Embed Size (px)
Citation preview
INOM EXAMENSARBETE FARKOSTTEKNIK,AVANCERAD NIVÅ, 30 HP
, STOCKHOLM SVERIGE 2016
Chassis layout of an autonomous truckA transportation concept for the mining industry
GABRIÉL-ANDRÉ GRÖNVIK
KTHSKOLAN FÖR TEKNIKVETENSKAP
Postal address Visiting Address Telephone Telefax Internet KTH Teknikringen 8 +46 8 790 6000 +46 8 790 6500 www.kth.se Vehicle Dynamics Stockholm SE-100 44 Stockholm, Sweden
Chassis layout of an autonomous truck
A transportation concept for the mining industry
Gabriél-André Grönvik
Master Thesis in Vehicle Engineering
Department of Aeronautical and Vehicle Engineering KTH Royal Institute of Technology
TRITA-AVE 2016:54 ISSN 1651-7660
.1
Chassis layout of an autonomous truck A transportation concept for the mining industry
E7011T Master thesis – Mechanical engineering, 30p
SD221X Master thesis – Vehicle engineering, 30p
Dahl Johannes
Grönvik Gabriél-André
16 June 2016
I
Abstract
Autonomous driving might increase safety and profitability of trucks in many applications. The
mining industry, with its enclosed and controlled areas, is ideal for early implementation of
autonomous solutions. The possibility of increased productivity, profitability and safety for the
mining industry and the mining area as a ground for development could, through collaboration,
result in many benefits for both mining companies and truck manufactures.
Scania must investigate how these autonomous vehicles should be constructed. The project goal
is thereby to develop a chassis layout concept for an autonomous truck. The concept should
improve profitability and safety for transportation of materials within the mining industry while
minimizing the introduction of new components to Scania.
The chosen approach is based on the Ulrich & Eppinger method for product development
including generation and selection of concepts. Product requirements were specified from
identified customer needs. The generated concepts were evaluated against these requirements
and comparisons were performed with weighted matrices.
Some benefits of the final chassis layout concept are a higher load carrying capacity, more
robust component placement and higher ground clearance. The vehicle concept would also be
able to operate in underground mines with low roof clearance which could open new market
segments for Scania. However, the concept requires development to gain higher performance
on load carrying components in the chassis front.
The suggested concept shows that Scania could build and deliver autonomous mining vehicles
with optimized chassis layouts based on Scania’s existing components within a near future.
Keywords
Autonomous, cab-less, driver-less, dump truck, chassis layout, hauling, mining transportation,
underground mines, open-pit mines, mining industry.
II
Sammanfattning
Autonom körning kan öka säkerheten och lönsamheten för lastbilar i många applikationer.
Gruvindustin, med dess avgränsade och kontrollerade områden, är ideal för tidig
implementation av autonoma lösningar. Möjligheten till ökad produktivitet, lönsamhet och
säkerhet med gruvindustrin och gruvområderna som plats för utveckling kan, genom samarbete,
resultera i många fördelar för både gruvföretagen och lastbilstillverkarna.
Scania måste därmed undersöka hur dessa autonoma fordon bör konstrueras. Projektmålet är
därmed att ta fram ett koncept på en chassilayout för en autonom lastbil. Konceptet bör öka
lönsamheten och säkerheten för transport av material inom gruvindustrin medan introduktionen
av, för Scania, nya komponenter minimeras.
Det valda angreppssättet är baserat på Ulrich & Eppingers metod för produktutveckling
inkluderande generering och urval av koncept. Produktkraven specificerades utifrån de
identifierade kundkraven. De framtagna koncepten utvärderades mot dessa krav och
jämförelser genomfördes med viktade matriser.
Några fördelar hos det slutgiltiga chassilayoutskonceptet är högre lastkapacitet, mer robust
komponentplacering och högre markfri gång. Fordonskonceptet har även möjlighet att köra i
underjordiska gruvor med låg takhöjd vilket kan öppna upp nya marknadssegment för Scania.
Dock kräver konceptet utveckling för att nå högre prestanda hos lastbärande komponenter i
främre chassi.
Det föreslagna konceptet visar att Scania skulle kunna bygga och leverera autonoma gruvbilar
med optimerad chassilayout baserat på Scanias existerande komponenter inom en snar framtid.
Nyckelord
Autonom, hyttlös, förarlös, gruvbil, chassilayout, gruvtransport, undergjordsgruvor, dagbrott,
gruvindustri.
III
Preface
This thesis was performed by Johannes Dahl and Gabriél-André Grönvik at Scania. Johannes
was studying Mechanical Engineering at Luleå University of Technology and has experience
in product development and great knowledge in machine design and components. Gabriél was
studying Vehicle Engineering at KTH and has competence in vehicle concepts, components
and dynamics.
The authors want to thank the supervisors Jenny Jerrelind at KTH, Torbjörn Lindbäck at LTU
and Måns Lundberg at Scania for their support and advices. We also want to thank other
personnel at Scania; our boss Christian Lauffs, Eric Falkgrim and Jan Dellrud for running this
project, Mikael Wågberg and Daniel Bergqvist for sharing their expertise about the mining
industry and everyone that we have been in contact with at Scania for exchanging many great
ideas. Finally, we want to thank all staff at RTMX for great support, good advice and
involvement.
IV
Contents
1 Background ......................................................................................................................... 1
2 Problem formulation ........................................................................................................... 1
2.1 Project aim and goals ................................................................................................... 1
2.2 Project delimitations .................................................................................................... 1
2.3 Risk analysis ................................................................................................................ 2
3 Approach ............................................................................................................................. 3
4 Market analysis ................................................................................................................... 5
4.1 The mining industry ..................................................................................................... 5
4.2 Operating conditions .................................................................................................... 8
4.3 Benchmarking .............................................................................................................. 9
4.4 Customer needs .......................................................................................................... 18
4.5 Legal requirements .................................................................................................... 18
4.6 Market opportunities .................................................................................................. 18
5 Product requirements ........................................................................................................ 20
5.1 Mission statement ...................................................................................................... 20
5.2 Function degradation ................................................................................................. 20
5.3 Product specification ................................................................................................. 22
6 Concept design .................................................................................................................. 23
6.1 Technical specification .............................................................................................. 23
6.2 Wheel configuration and powertrain ......................................................................... 24
6.3 First concept selection ............................................................................................... 31
6.4 Bodywork and main components .............................................................................. 33
6.5 Second concept selection ........................................................................................... 44
6.6 Finalizing ................................................................................................................... 45
7 Final concept ..................................................................................................................... 46
8 Suggestions on new parts and modifications .................................................................... 49
9 Discussion and conclusions .............................................................................................. 51
10 Future work ................................................................................................................... 53
Appendix A ............................................................................................................................ A.1
Appendix B ............................................................................................................................ B.1
Appendix C ............................................................................................................................ C.1
Appendix D ............................................................................................................................ D.1
Appendix E .............................................................................................................................. E.1
Appendix F .............................................................................................................................. F.1
V
List of figures
Figure 1: Scheme of general product development process. ................................................................... 3
Figure 2: Final workflow. ........................................................................................................................ 4
Figure 3: Open pit mine [5]. .................................................................................................................... 5
Figure 4: Schematic of an underground mine [6]. ................................................................................... 6
Figure 5: Transportation solution within the mining industry. ................................................................ 6
Figure 6: Open pit mine material flow [7]. .............................................................................................. 7
Figure 7: Value creation of mining transportation tasks. ........................................................................ 9
Figure 8: Rigid haul tuck [15]. .............................................................................................................. 10
Figure 9: Articulated haulers, (a) underground use [16], (b) over-ground use [15]. ............................. 10
Figure 10: Scania dump truck [17]. ....................................................................................................... 11
Figure 11: EcoTwin platooning [20]. .................................................................................................... 12
Figure 12: Mercedes-Benz 2025 highway pilot concept [23]. .............................................................. 12
Figure 13: Komatsu autonomous haulage system in Australia [27]. ..................................................... 13
Figure 14: Function degradation including eleven different sub-categories. ........................................ 20
Figure 15: Reference truck used in Vehicle Optimizer. ........................................................................ 24
Figure 16: Cab-less truck with forward extended body. ....................................................................... 25
Figure 17: Cab-less truck with stronger front axles. ............................................................................. 26
Figure 18: Cab-less truck with shortened axle distances. ...................................................................... 26
Figure 19: Cab-less truck with greater overhang................................................................................... 27
Figure 20: Extended, cab-less truck with support axle and centred bogie. ........................................... 27
Figure 21: Cab-less truck with front extended frame and steering axles. ............................................. 28
Figure 22: Axle ground clearance. ........................................................................................................ 30
Figure 23: Ground clearance of frame mounted components. .............................................................. 30
Figure 24: Wheel configuration and suspensions. ................................................................................. 31
Figure 25: First suggestion of performance step. .................................................................................. 32
Figure 26: Second suggestion of performance step. .............................................................................. 32
Figure 27: Piston unloading material [32]. ............................................................................................ 33
Figure 28: Tipping the whole truck [33]. .............................................................................................. 33
Figure 29: Falling object protection system [35]................................................................................... 34
Figure 30: High air intake, forward position. ........................................................................................ 35
Figure 31: High air intake, angled forward position. ............................................................................ 35
Figure 32: Silencer positions, illustrated by large silencers. ................................................................. 36
Figure 33: 200G Fuel tanks right and left hand position. ...................................................................... 37
Figure 34: 300G Fuel tank left hand position. ....................................................................................... 38
Figure 35: AdBlue tank positions. ......................................................................................................... 38
Figure 36: Front axel air tanks positiones. ............................................................................................ 39
Figure 37: Rear axle air tanks positiones. ............................................................................................. 39
Figure 38: Air processing system, left corner position. ......................................................................... 40
Figure 39: Horn, repositioned left corner. ............................................................................................. 40
Figure 40: Steering servo left and right hand positon. .......................................................................... 41
Figure 41: Engine cover from R-cab floor. ........................................................................................... 42
Figure 42: Large engine cooler.............................................................................................................. 42
Figure 43: Front interface layout with cut corners. ............................................................................... 43
Figure 44: Washer tank, left corner position. ........................................................................................ 43
Figure 45: Example truck specified with parts from concept selection two.......................................... 44
Figure 46: Final concept. ....................................................................................................................... 46
VI
List of tables
Table 1: Risk analysis. ............................................................................................................................. 2
Table 2: Tasks of Planning and Concept development phase in original method. .................................. 3
Table 3: Truck components divided into three categories, phase 1, phase 2 and phase 3. .................... 21
Table 4: Summary of product specification. ......................................................................................... 22
1.1
1 Background
Scania has provided heavy trucks for the transport industry for the last 120 years and during the
last 15 years they have been involved in the mining industry. This worldwide mining industry,
found in deserts to jungles and arctic settings, is known for its rough and harsh environment [1].
Scania is currently delivering manually driven trucks for the transportation of ore and waste in
the mining industry. With the constant competition in the vehicle industry it is important to find
new, more cost efficient, solutions to transportation. An autonomous vehicle has the potential
to make the transportation more efficient since it does not require a driver. Hence the vehicle
does not require any cab which enables a variety of chassis layouts rather different from the
standard Scania trucks of today. The new degrees of freedom enable new, possibly more
efficient and flexible, vehicle concepts that may increase profitability for the customer. It is
thereby important for Scania to explore these possibilities and investigate how and to which
extent they could include these vehicles in their portfolio. Scania has therefore employed five
groups of master thesis students within the subjects; chassis layout, communication, sensors
vision, sensor placement and lighting. The students will cooperate with the aim to develop a
vehicle concept of an autonomous mine transportation vehicle.
2 Problem formulation
2.1 Project aim and goals
The overall question, leading to this project, was how Scania should include driverless, cab-
less, efficient and flexible autonomous vehicles with the existing Scania bygglada in mind.
Where the bygglada is Scania’s modular system including all truck components with several
performance steps. A suitable environment for developing autonomous trucks would be an
enclosed and controlled area such as a mine. Accordingly, the projects main aim was to
investigate how a chassis layout for an autonomous mining vehicle for transportation of ore and
waste can be realized with Scania’s existing bygglada. The secondary aim was to give
suggestions of modifications of existing components or new components that could be added
to the bygglada for future concept development.
The result will be supporting decisions regarding Scania’s future development of autonomous
trucks within the mining industry. The project will also guide future concept development.
The project goal was to develop a vehicle with better performance than the conventional
solutions on the market today, such as higher availability, flexibility, lower environmental
impact, greater personnel safety and be more profitable for the customer. The vehicle should
also be able to equip different bodyworks.
2.2 Project delimitations
The project was performed by two engineer students in 20 weeks, see Appendix A, during the
spring of 2016.
The chassis should be designed for the mining industry based on Scania’s bygglada. It should
also originate from the current standard frame width, frame cross section and frame bend angle
2
used by Scania today as well as the existing powertrain. These components are crucial to the
modularity of Scania’s bygglada and have been a great investment. The concepts should be
developed from the customer needs and applications identified in the pre-study ”Förstudie om
autonoma fordon i gruvindustrin” by Alina Ekström and Josephine Sörensen [2]. As well as
requirements from the other master thesis groups.
The autonomous vehicle is intended to operate within demarcated and controlled areas, and not
on public roads. However, future mining vehicles might operate in both areas and the possibility
to drive on public roads is therefore advantageous.
2.3 Risk analysis
In order to prevent unnecessary harm to the project a risk analysis was made, shown in Table 1
below. This analysis displays identified risks during the project. Prevention plans are stated in
order to prevent the risks from occurring. There are also action plans if one of the risk were to
occur. The possible damage is rated from 1-5, where 1 is a minor disturbance and 5 is a huge
setback. The probability is also rated from 1-5, where 1 is very unlikely and 5 is very likely.
The score is a product of damage multiplied with probability and ranges from 1-25, where
anything above 10 is a risk that has to be solved. Our analysis shows that none of the risks are
scored high enough to make changes in the approach or the problem formulation. However, if
a risk would have emerged during the project with a higher score than 10 it would have been
solved to ensure that the project runs with as little risks as possible.
Table 1: Risk analysis.
Risk Damage Probability Score Prevention plan Action plan
Data loss 5 1 5 Keeping data on Scania network Restore as much as
possible, rewrite
Missed deadlines 2 3 6 Continuous follow-up of GANTT Reschedule
Illness - Minor 1 3 3 - Communication and
rescheduling
Illness - Major 5 1 5 - Change of scope and
goal, contact mentor
Lack of competence 1 5 5 Literature study Consult experts within
the area
Lack of project
resources 4 2 8 Continuous follow-up of GANTT
Revise scope and goal,
contact mentor
3
3 Approach
The final concept was to be generated through a modified version of the general product design
process described in “Product Design and Development” [3]. The process, shown in Figure 1,
consist of six phases; Planning, Concept development, System level design, Detailed design,
Testing and refinement and Production ramp-up. Since the project result, as specified in 2.1
Project aim and goals, should be a final concept only the two first phases of the design process
will be used.
Figure 1: Scheme of general product development process.
The two phases can be broken down in to four main areas; market, design, manufacturing and
other functions according to Table 2.
Table 2: Tasks of Planning and Concept development phase in original method.
Planning Concept development
Marketing
Articulate market opportunity.
Define market segments.
Collect customer needs.
Identify lead users.
Identify competitive products.
Design
Consider product platform and
architecture.
Assess new technologies.
Investigate feasibility of product
concepts.
Develop industrial design concepts.
Build and test experimental prototypes.
Develop product architecture.
Manufacturing
Identify production constrains.
Set supply chain strategy
Estimate manufacturing cost
Assess production feasibility.
Other functions
Research: Demonstrate available
technologies.
Finance: Provide planning goals.
General management: Allocate project
resources.
Finance: Facilitate economic analysis.
Legal: Investigate patent issues.
PlaningConcept
developmentSystem level
designDetailed design
Testing and refinement
Production ramp-up
4
Financial, legal and supply strategies are outside the scope of this project. Market opportunities
and segments as well as customer needs has been identified in the pre-study “Förstudie om
Autonoma Fordon I Gruvindustrin” [2]. Though both were considered as requiring further
investigation, or at least confirmation since the pre-study was done in 2012. The market and
customer demands might have changed during the past four years. The remaining tasks forms
the design process and was ordered into six phases as shown in Figure 2.
Figure 2: Final workflow.
The first step in the project was to state a project scope and an initial plan of the project
resources. The second step was then to understand and verify the customer needs, operating
environment and conditions, demonstrate available technologies through benchmarking and
document related technologies. A comparison between the potential of the autonomous vehicle
and the conventional solutions could then be performed. This would give the possibility to find
areas where the autonomous vehicle is competitive.
Based on the identified situations, where the autonomous vehicle has an advantage, a
requirement specification was created to define the vehicle. It is also against this specification
that the vehicle was verified. The chassis layout was then developed during three phases,
assessing different parts of the vehicle concept. The overall vehicle concept was developed
through iteration and the different subsystems were chosen by narrowing down developed
concepts through selection. The selections were done based on related literature and
consultancy from experts at Scania. The final concept is the result of the overall layout concept
and the concepts chosen for each subsystem. Suggestions on new components or changes to
existing components were also made.
In order to achieve the goal, the following questions were answered:
What are the customer needs regarding transportation of ore and waste?
How are conventional ore and waste transportation vehicles designed and used today?
What potential is there in autonomous mining vehicles?
What is required of the vehicle?
How is the set of requirements effecting the vehicle chassis layout?
How can the layout be optimized to the new circumstances?
What new components or modifications to existing components should be included in
the chassis layout?
How is maximum customer value achieved?
What are the benefits of a new layout?
5
4 Market analysis
The market analysis consists of three main sections. An overall description of the mining
industry describing the different mine types and material flows. A definition of the operating
area and identification of operating conditions addressed by the project. A benchmark of
competitive solutions and solutions available at Scania. The benchmarking consisted of five
main areas;
Common transportation concepts within the mining industry.
Components from Scania’s bygglada relevant for heavy-duty dump trucks.
Competitive solutions on specific problems and subsystems.
Scania’s autonomous trucks today.
Competitors’ development of autonomous trucks.
The market analysis also identifies customer needs and relevant legal requirements. Finally,
Scania’s position on the market and future market opportunities are discussed.
4.1 The mining industry
The mining industry spans many countries all over the world such as South Africa, Russia,
Australia, Ukraine, Guinea and Sweden. There are different mining strategies including several
transportations of waste and ore in an environment that is harsh and dangerous for both workers
and vehicles.
4.1.1 Mining strategies
There are two main types of mines, open pit mines and underground mines. When choosing
which type of mine to operate there are many factors to take into account; size, shape and depth
of the deposit, rock conditions, productivity, and costs are a few examples. An open pit mine is
commonly used when excavating a near surface deposit [4]. The ore is excavated by using
horizontal benches to get deeper into the ground, see Figure 3.
Figure 3: Open pit mine [5].
6
Underground mining is used if the ore deposit is shaped in a way that isn’t beneficial for open-
pit mining or if surface mining has gone deep enough that underground mining is the next
logical step to keep production rates high and costs low [4]. A schematic of an underground
mine can be seen in Figure 4.
Figure 4: Schematic of an underground mine [6].
The material flow in a mine vary depending on what is extracted, the mines location, if it is an
open pit or underground mine as well as the strategies chosen by the mining company. An
illustrated overview of the transports within a mine can be seen in Figure 5. In contrast to coal
mining, ore mining requires pre-processing before shipment. In the pre-processing the ore is
grinded into smaller stones. This creates one transportation from the mine to the grinder and
one transportation from the grinder to a long distance transport. The long distance transport is
usually a train or a ship. In a coal mine, on the other hand, the material can be transported
directly from the pit to the long distance transport. Though if the distance is long, it might be
beneficial to reload the material onto a long haulage truck once out of the mine.
Figure 5: Transportation solutions within the mining industry.
7
A typical material flow from an open pit mine extracting ore, is shown in Figure 6. The process
in an underground mine is in principle the same, with the difference that the first transportations
takes place in tunnels. The in-pit or underground transportation takes place between the loading
of the blasted material to the unloading at the crusher. A second vehicle transportation moves
the material to the long distance transport.
Figure 6: Open pit mine material flow [7].
4.1.2 Safety
The mining industry is among the most dangerous industries in the world [8] and a common
problem for all transportation solutions are accidents and deadly accidents in particular [9].
Manual systems are prone to human error and in an analysis of mining incidents, unsafe acts of
the operator were associated with 81.9% of the accidents [10]. Manual systems also involve
more personnel. An investigation on fatal dump truck accidents shows that truck drivers
accounted for 36% of the deaths during 1992-2007 [11]. This indicates that many accidents and
deaths can be avoided by introducing autonomous trucks.
8
4.2 Operating conditions
This project addresses the first transportation in the mine, either over ground or underground,
from loading of the blasted material to the pre-processing or reloading of the material. That is
not outside the mining area and on no public roads. The transported material may vary from
coal to waste and ore.
4.2.1 Environment
As mentioned earlier, dump trucks in the mining industry are working in very harsh
environment. The operating conditions are putting trucks to the test and the expected life span
of a vehicle is about three and a half to four years [12]. The trucks have to withstand for example
rough roads, mud and dust, ice and snow, rocks and stones, temperatures ranging from -50 to
50 degrees Celsius, different humidity and all types of weather [2]. Today most of the mines
are located below 2000 meters in altitude with the exception of mines in Peru where they are
located at an altitude above 4000 meters [13]. In addition, when operating in an underground
mine, blast gases and the risks of cave in after blasts has to be considered.
4.2.2 Terrain
The terrain in mines differ, open-pit mines usually have gradients from 10-16% and
underground mines around 14-19%. The road conditions are very different depending on what
kind of mine it is. Open-pit mines are ranging from rough, very rough to off-road conditions
and are also affected by weather. A road can be washed away or turned into a mud puddle and
the terrain can change from one hour to another. Underground mines have more constant road
conditions and are not affected by the weather to the same extent. In underground mines, there
are many narrow passages and the ceiling can be very low from just under 3 to about 4 meters
[14].
4.2.3 Daily operation
The average annual mileage for a mining dump truck is 60 000 – 210 000 kilometres, this
mileage is covered in 6 000 – 7 000 hours. During this mileage there are continuous stops for
loading, unloading and meeting of other vehicles and personnel in narrow passages. A mining-
truck can do up to 200 runs in one day. The speed limit differs depending on country and the
mining companies own policies. In India there is a speed limit of 40 km/h, in Brazil 45 km/h
and in Indonesia 60 km/h. However, the average laden speed is usually 10-30 km/h within the
mine [13].
9
4.2.4 Customer profitability
To reach a high profitability it is important to understand the vehicle tasks. These can be divided
into three main categories; value creating tasks, non-value creating tasks and necessary but non-
value creating tasks. As illustrated in Figure 7, a mine hauling truck is value creating when
laden and transporting to the unloading station. Two good examples of necessary but non-value
creating work are refuelling and driving the truck unladen to the loading point. Examples of
non-value creating tasks are queuing, driver breaks and changeover of drivers.
Figure 7: Value creation of mining transportation tasks.
4.3 Benchmarking
4.3.1 Transportation concepts
The identified competition consists of manual or autonomous road and rail vehicles and
automatic conveyor systems.
The pre-study [2] states that the autonomous trucks have a good opportunity when either of the
loading or unloading point, or both, are mobile. Since conveyors and rail vehicles don’t have
the same flexibility as road vehicles, they are mainly a competition when transportation takes
place between two fixed points, and are thereby not considered as a big competitor.
Three main road vehicle categories were identified; rigid haul trucks, articulated mining haulers
and dump trucks.
Rigid haul trucks
Rigid haul trucks, see Figure 8, has a payload ranging from about 30 tonnes to over 360 tonnes
resulting in gross vehicle masses from about 60 tonnes to over 560 tonnes. The load is typically
distributed on two axles holding a total of six wheels. They can be as high as 8 meters, with a
maximum height of 16 meters while tipping, almost 10 meters wide and over 15 meters long.
Compared to their height, they have a relatively short wheelbase resulting in an outer turning
radius of about 20 meters for the largest trucks. The trucks normally have a combustion engine
10
but can also be equipped with a hybrid powertrain with an electrical motor. There are examples
of rigid haul trucks with pantographs that attaches to overhead lines in steep inclinations or over
longer stretches [15].
Figure 8: Rigid haul tuck [15].
The rigid haul trucks require broad roads and can have such a high payload that it takes even
the larger excavators several batches to fill, resulting in idling time. On the other hand, the high
payload allows one single driver to transport large amount of material but this is no longer an
advantage when trucks are automated. When the haul truck needs maintenance up to 363 tonnes
of payload capacity is standing still. The customer might need many extra tons in payload to be
able to operate continuously. With high payloads there are a lot more requirements on the
surroundings during both loading and unloading. The loaders have to be bigger in order to
minimize the loading time and the ore crushers have to be able to handle a big load. With a
wider vehicle the roads have to be a lot wider resulting in either a bigger pit or less depth of the
mine. Both of these results in less profits. The vehicles are also very specialized and thereby
requires many unique components.
Articulated haulers
The articulated haulers can be divided into two subgroups. Haulers for underground or over-
ground use, (a) and (b) respectively in Figure 9. They carry about the same amount of payload
from 20 tonnes to 60 tonnes and has similar gross vehicle mass on 40 tonnes to a bit over 100
tonnes and have about the same dimensions. On the over-ground vehicles, the load is typically
distributed on three axles holding a total of six wheels. The underground vehicles on the other
hand, often have two axels holding four wheels in total. Both the over and underground trucks
are about 2 to 3 meters high and 5 to 6 meters high while tipping, where the over ground haulers
are slightly higher than the underground haulers. The vehicles overall width spans from about
2.4 to 3.5 meters and the length is typically 9 to 11 meters [15] [16].
Figure 9: Articulated haulers, (a) underground use [16], (b) over-ground use [15].
11
Characterizing for underground haulers is the low profile, suited for the low roof in the tunnels,
with the components placed up to the maximum height of the body. These vehicles outer shape
is also optimized for tight corners, often having a chamfered front and rear minimizing both the
outer and inner turning radius [15].
The joint just behind the cab and engine allows for rotation around all tree axis and give the
trucks a tight outer turning radius of about 7 to 10 meters. The joint makes the vehicle well
suited for rough and uneven terrain. The vehicle’s main drawback is that it is very specialized
and thereby requires many unique components [15].
Dump trucks
Dump trucks, see Figure 10, are typically basic trucks with a payload ranging from 15 to 70
tonnes and a gross vehicle mass from about 30 to 100 tonnes. A dump truck specified as a
heavy-duty truck usually has multiple steering and driving axles to enable maximum load
carrying capacity and payload. Trucks for use on public roads are limited by regulated
dimensions which may vary between countries. The most common limits to the outer dimension
are; width 2.55 meters, height 4 meters and length 12 meters. The unloading of the truck is
usually performed by tilting the body over the rear end or sideways.
Figure 10: Scania dump truck [17].
The main advantage of trucks is their diversity and flexibility in both layout and usage. Trucks
can relatively easy be built for different tasks, loads and operating conditions while taking
advantage of cost reduction through larger volumes and common solutions. However, the
diversity of trucks also mean that it never becomes truly specialized. The smaller size of trucks
lowers the amount of unavailable load carrying capacity during down-time and allows for
narrower benches in open-pit mines. This enables steeper and deeper pits which may result in
higher profit by avoiding overburden and allow a bigger fraction of the ore body to be mined
within the open-pit. A typical dump truck is also allowed to drive and transport material on
public roads which could make reloading unnecessary and transportation more efficient.
Autonomous transport solutions
EU is recognising autonomous trucks as a future transport solution. EU Truck Platooning
Challenge 2016 is an initiative from the Netherlands who holds the presidency of the Council
of Europe of the European Union. The challenge is a cross boarder project with the truck
12
manufactures DAF Trucks, Daimler Trucks, Iveco, MAN Truck & Bus, Scania and Volvo
Group. The goal is to bring political attention to autonomous driving in Europe and to accelerate
the development of smart mobility [18].
DAF and TNO has presented what is called EcoTwin, see Figure 11. A concept where a second
truck autonomously follows a first leading truck driven by a driver. DAF’s goal is to have a
system on the roads commercially before the year 2020 [19].
Figure 11: EcoTwin platooning [20].
Mercedes are developing a truck for the year 2025, shown in Figure 12, with a high level of
automation relieving the driver on highways. The system is called Highway Pilot and manage
accelerating, braking and steering. The vehicle supports vehicle-to-vehicle communication
allowing it to alert the driver of approaching emergency vehicles. It also notifies the driver on
slow vehicles blocking the trucks lane. The system is a type of autopilot. The truck is equipped
with rear cameras rather than mirrors and side mounted radars to cover the blind spot. However,
Dr. Wolfgang Bernhard at Mercedes concludes that laws and regulations have to change and
national lawmakers needs to take action for these vehicles to be able to drive on public roads
[21] [22].
Figure 12: Mercedes-Benz 2025 highway pilot concept [23].
13
Komatsu is offering FrontRunner® Autonomous Haulage System, Figure 13. A system of
haulage trucks that can start, navigate along routes, recognize other trucks and vehicles as well
as load and unload autonomously. A central computer is keeping track of, controlling and
analysing the trucks in real time. These vehicles are able to work long shifts and does not require
the same amount of stops as a manually driven truck. The system has been implemented and is
tested in mines in Australia [24] [25] [26].
Figure 13: Komatsu autonomous haulage system in Australia [27].
4.3.2 Scania bygglada
A mining truck consists of many subsystems and a selection of components were considered
relevant for the vehicle concept. These components include the air tanks, axles, batteries, bodies,
brakes, cooling, electrical control units, framework, fuel tanks, pneumatic systems, power take-
off units, powertrain, after-treatment and exhaust system, air intake, steering, storage, wheel
suspension and wheels.
Air inlet and outlet
The air for the engine combustion is usually taken from the front or closer to the roof via a
snorkel. The snorkel is common for heavy duty trucks and is used in order to get cleaner air
with less dust. The snorkels can have different length and be fastened to either the cab or the
chassis.
The position of the exhaust pipe on the trucks also vary. Its outlet can be placed to the left hand
side, right hand side, in the middle of the cassis or vertically behind the cab. A high exhaust
pipe requires more space but, besides looking powerful, it keeps the outlet out of water and mud
as well as avoiding stirring up dust. If the opening gets blocked the engine has to pump the
exhaust against a higher pressure resulting in higher fuel consumption or lower power output.
Swirling dust increases the need of maintenance hence by minimizing dust in the operating
environment the maintenance cycle can be extended [14].
Axles
There are many different kinds of wheel setups. The number of wheels on a Scania dump-truck
usually varies from 6 to 16 on 3 to 5 axles. Axles can be either steering, driving, both steering
and driving or simply supporting. An axle normally holds two or four wheels and can be
arranged separately or together as bogies with typically two axles. Wheels can sometimes be
raised in order to lower the rolling resistance during unladen operation or to increase traction
by increasing the load on the driving axle. Heavy duty trucks normally have rear-wheel drive
14
or all-wheel drive. They normally steer with one or two axles in the front but may also have
steering axles in the rear.
Batteries
Scania offers batteries in two different setups, single and double configuration which both offers
several different battery capacities. The single configuration consists of two 12 V batteries in a
group giving 24 V and the double configuration consists of two of these groups. The double
configuration is used to ensure that at least one group of batteries is charged so that the truck
can be started.
Bodies
Scania does not build any bodies, instead Scania’s trucks are built so that different bodies can
be fitted. For mining applications, the body typically consists of a flatbed and a subframe. While
the flatbed holds the material, the purpose of the subframe is to make sure that the bodywork
has the right stiffness and flexibility. The subframe also provides an interface to the truck frame
with enough clearance between the flatbed and the wheels and helps distributing the load on to
the truck frame.
There are several different unloading techniques and the most common is the possibility to tip
the body in one or two directions. Bodies for mining applications on Scania trucks are usually
rear or side tipping.
Brakes
Scania uses two main types of brakes, disc and drum brakes, which are powered by a pneumatic
system. Drum brakes are robust and enclosed which makes them suitable for harsh
environments.
Scania also has two supporting brake systems; an exhaust braking system and the retarder. The
exhaust brake is implemented in the exhaust pipe and works by creating a higher exhaust
pressure resulting in a higher resistance for the engine. The system is more powerful at low
speeds and high engine rpm. The retarder, developed by Scania, is a hydraulic system mounted
on the gearbox and generates most braking power in high speed [28].
Cooling
The cooling of the engine is critical to maintain a high efficiency and low emissions. On Scania
trucks the cooler is solely positioned in the front. The cooling effect is highly dependent on the
size of the cooler which needs to provide the required cooling power. This is usually achieved
solely by the head wind but when the speed is too low a fan mounted on the engine behind the
cooler helps to increase the airflow.
Electrical control units
Many components on the truck require control by electrical control units, ECUs. There are
currently several ECUs mounted on the truck and the number depends on the truck
configuration. With an autonomous vehicle it is likely that the number of ECUs will increase,
even though some will be removed together with the cab.
Framework
The framework consists of different components, such as side members and crossmembers.
Scania’s side members consist of U-profiles which allows torsion while having a high load
carrying capacity. To increase the load carrying capacity a side member reinforcement can be
used. The side members are bent to create a Y-shape which enables the engine with mounts and
15
gearbox to fit. The crossmembers consists of single plate U-profiles which connect the
sidemembers.
Fuel tanks
The fuel tanks are made in different material and sizes. Diesel tanks are made out of aluminium
or aluminized steel depending on the requirements on robustness, corrosion and weight. Scania
has a cylindrical aluminium tank that is specially designed for harsh environments such as rough
roads where there are much vibrations [28].
Horn
The horn is used for signalling and is located in the front, lower left corner, of the truck.
Pneumatic system
The pneumatic system is crucial on a Scania truck. It provides power to the brakes and may
power trailers, air suspensions and the vehicle body. The system includes a compressor
mounted on the engine followed by an air dryer, a pressure regulator and several air pressure
tanks.
There are different air pressure tank sizes depending on their positions. The sizes range from
10 litres up to 36.5 litres per air tank. There are some restrictions regarding the placement of
the tanks. The tanks must be placed within sufficient range from the brakes to reduce the delay
and must hold a sufficient volume and pressure of air. An air suspended chassis must also carry
extra volume of air for the air springs. A regular non-air suspended 8x4 has 50-60 litres of
compressed air for the front axles and 80-105 litres for the rear axles [29].
Power take-off
The vehicle can be equipped with different power take-off units, PTOs. Engine-driven,
flywheel-driven, gearbox-driven and transfer driven power take-off units in case of all wheel
drive. When choosing power take-off unit there are many parameters to take into account hence
a dialog with the bodybuilder is necessary.
Powertrain
The main components of the powertrain are the engine, clutch, gearbox, propeller shafts, a
transfer gearbox in case of driven front axles and optionally a hub reduction gear. Scania’s
engines are world leading in performance and emissions. Heavy duty trucks are equipped with
diesel engines that may be set up in a hybrid configuration even though there are no examples
of that today among Scania’s mining trucks. In the hybrid configuration an electric motor is
attached in between the engine and the gearbox, extending total length of the package.
In fully automated Opticruise, providing automatic gearshifts, the clutch is operated by an
electric actuator and therefore require no clutch pedal. The gearbox can also be equipped with
an oil cooler. This is important if the engine often runs on high engine speed combined with
low gear or if the PTO is used often. Automatic gearboxes are not produced by Scania but
bought from suppliers. The automatic gearbox is especially good for trucks with many starts
and stops.
Hub reduction gears, also known as final planetary gears, provides extra torque which facilitates
starting in inclinations and on poor road surfaces easier.
16
SCR-system
Scania SCR (selective catalytic reduction) is an after-treatment system that minimises the
nitrogen oxide (NOx) levels in the exhaust gases. This is done by injecting urea-based additives,
AdBlue, into the exhaust gases which converts the nitrogen oxides into water and nitrogen. The
injection of AdBlue is done by a nozzle inside the silencer which has many different sizes
depending on engine power and emission class. There are also different sizes of the AdBlue
tank, ranging from 47 to 124 litres. The AdBlue tank can be positioned on either side of or
under the frame.
Steering
Front axles are steered by a draglink arm connected to the steering servo positioned in the front
right or left hand corner.
Storage boxes
The storage boxes are frame mounted and used to store tools and components. They come in
three sizes; 600 m, 620 mm and 1000 mm in length [30].
Washer tank
The washer tank is located in the front left corner. It is currently being used to clean windscreens
and headlights.
Wheel suspension
Depending on the vehicle application different wheel suspensions are used. The main two
categories are air and leaf springs which can be used in different combinations. Air springs give
good comfort regardless of the load and the possibility to raise and lower the vehicle chassis.
Leaf springs are used when robustness and simplicity is important and the loads are heavy.
Scania has two main types of leaf springs; parabolic and trapezoidal springs. Parabolic springs
gives better comfort and has relatively low weight which allows for more payload. They also
have a longer life time than trapezoidal springs. Trapezoidal springs can take high loads and
does not require dampers but they are heavy and usually used when there are no restrictions on
vehicle weight [28].
Wheels
Almost all rims at Scania are tubeless. Rims in steel are more durable but heavier then rims in
aluminium and are common in construction and mining vehicles [28]. Depending on the
operating environment different tires are used and the most common tire for heavy-duty
applications is a larger off-road tire.
4.3.3 Unconventional solutions
There are examples of bodies that enable unloading via hatches underneath the body, pushing
the load of the flatbed or unloading it with a rolling belt. These methods do not require the body
to be tilted at all and can be effective in tight environments.
There exist many different and some unconventional wheel setups. Bogies can have up to three
axles and there are vehicles with up to 20 wheels on up to 5 axels, all-wheel drive and all-wheel
steering. There are some examples of vehicles able to steer close to 90 degrees on the front axle
and some have separate axles on each side making it possible to steer the wheels individually.
Also some trucks and trailers are tracked rather than having wheels.
17
There are examples of electrified transportation solutions in mines where hybrid trucks are used.
These trucks can also utilize pantographs for recharging during operation or extending the
vehicle electric range. It is then advantageously to position the overhead wires in steeper slopes
or long stretches where the road will not be rerouted for a longer period of time.
4.3.4 Scania autonomous trucks
An autonomous mining vehicle must be able to detect other vehicles, pedestrians and objects
as well as understanding and judging the terrain. The vehicle also has to be able to communicate
with other vehicles and the control centre. To monitor the surroundings, the vehicle utilizes
different sensors such as cameras and radars. The sensors complement each other by providing
vision of different kinds of objects at different ranges from the trucks as well as giving some
redundancy. The sensors require a protected environment, safe from water, rocks, mud and dirt.
One of the biggest concerns, when it comes to blocked vision, is dense particles containing
water such as wet snow or slush.
The communication between vehicles and the communication central is performed via antennas.
The antennas must be able to emit and receive signals all around the truck. The signalling
antennas also require clearance against metal objects that otherwise would block the signal.
Only minor changes in the chassis layout are mandatory to automate trucks. Sensors, antennas
and light for vision and communication are needed to be able to navigate the truck as well as a
positioning system to accurately determine the position of the truck. To be able to steer the
truck autonomously an electrical steering actuator controlling the steering mechanism is
required.
Camera
The camera has a broad field of view and generates a high resolution measurement but its range
is limited. The camera has to sit behind a transparent and clean surface in a protected
environment. The position of the camera highly influences its measurement. A lower camera
can easier identify irregularities in the ground. The camera also benefits from sitting on a rigid
part of the vehicle since it is dependent of knowing its exact position. On Scania’s autonomous
trucks today, the camera is sitting behind the windscreen in the suspended cab which creates
complications.
Radar
Radars are good at detecting hard surfaces reflecting its signal but not as effective on soft
objects such as pedestrians. A radar is quite robust and does not require a very clean operating
environment. Radars may also be covered by plastic housings without disruption of the signal.
4.3.5 Scania mining truck specifications
Scania mining trucks are usually specified with 3 to 5 axles and four driven wheels. They have
a load carrying capacity of 22 to 37 tonnes, loading 9 tonnes on a front axle, 18 tonnes on a rear
axle and up to 14 tonnes on a tag axle. The vehicles are equipped with drum brakes, leaf springs
and off-road wheels.
18
4.4 Customer needs
The main function of a transportation vehicle is to hold and move material. In order to do this
within a mine many other requirements occur. A full list of these requirements related to the
chassis layout can be found in Appendix C.
The vehicle has to be compatible with the loader and unloading stations. It also has to be able
to work in different climate and weather, drive on rough terrain, level differences and varying
road conditions. To navigate the mine, the vehicle also has to be able to take sharp turns and go
around tight corners, see 4.2 Operating conditions. Due to the harsh environment the customer
demands robust vehicles with lasting chassis and body [2].
Other important properties are simple, quick, gentle and secure loading and unloading. The
truck should minimize operating cost, maintenance and idling time. It should also be able to
operate continuously for long hours. The customer wants a flexible vehicle able to fit different
bodies and able to transport different material. The safety of the personnel is of high priority
within the industry. The truck should therefore lower the risk of accidents, and personnel also
has to feel safe around the vehicles [2].
4.5 Legal requirements
Vehicles in the mining industry does not need to follow the regulations of road vehicles since
the area in which they operate is considered enclosed. The only regulations that the vehicles
need to fulfil are the emission and work-related regulations in each country. Though the
customer often demands that the vehicle fulfils the regulations of public roads. It is currently
not possible to operate an autonomous vehicle on public roads as there are no laws or
regulations allowing that. To enable an autonomous vehicle to operate on public roads it has
to fulfil many of the requirements of a normal truck as well as the upcoming laws and
regulations regarding autonomous vehicles.
4.6 Market opportunities
Scania’s largest markets are currently located in Brazil, Indonesia, India, Peru, Chile, Russia,
South Africa and Australia. Not all of these markets are suited for autonomous mining vehicles,
at least not in all parts of the mine. However, there are customers that would buy autonomous
trucks if Scania offered these today [14].
The majority of Scania’s sales in mining are for open-pit mining and there are only few
examples of Scania trucks running in underground mines, mainly due to low roof clearances. If
autonomous vehicles could solve this issue, there would be a new potential market in
underground mining for Scania.
The largest potential for trucks is found where the mine is not adapted for rigid haul trucks.
That includes smaller mines, old reopened mines or mines about to open, where trucks can be
sold as the transport solution from the start [12]. Scania is for example not selling in-pit trucks
in Australia. It wouldn’t be possible to compete against the rigid haul trucks as the infrastructure
and loaders are dimensioned for those vehicles. To resize the mine and adapt it to trucks would
be too costly for the customer [14].
19
Autonomous vehicles make the mining process more cost efficient by removing the driver. This
does not only save the cost of the salary but the mining company does not need to build
infrastructure to the same extent. Today some mining companies have to build hospitals,
apartments, airports and stores, as well as providing bus transportation only for their drivers.
Fewer or no drivers would decrease the need of supporting infrastructure.
The removal of the driver will also make more uptime available. There are several occasions
where the driver cannot or should not operate. For example, due to toxic blast gases that occurs
after a blast. These gases have to be ventilated before a driver can work at that location. Other
occasions could be breaks or driver changes. Without the downtime caused by drivers there will
be an increase of uptime and productivity.
Another limiting factor for manually driven trucks is the need of driver recruitment and
education. It is sometimes hard to find enough drivers when the mine is expanding. In some
markets it is common that the drivers lack driving skills. Many of the drivers are not educated
truck drivers and they may not even have a license for a regular car. This is especially
problematic in India where the circulation of drivers is very high. Scania is therefore unable to
keep up with driver education which normally is an important part of Scania’s business idea.
An autonomous truck is programed for efficient driving which lowers wear and saves fuel while
minimising risks for accidents. An autonomous truck fleet is also more predictable which
enables better management and utilisation of the trucks [31].
20
5 Product requirements
In order to state a distinct course and establish a strong foundation for the concept generation
the product requirements were identified. This was done with a mission statement and a product
specification. As a complement and to ensure that the problem is fully thought through, a
function degradation was performed. The product functions and components as well as their
correlation were identified.
5.1 Mission statement
The course for the concept development is expressed by the mission statement. The mission
statement guides the development process and help to ensure that the project is progressing in
the right direction. The statement was based on the identified main requirements; autonomous,
cab-less, safe, profitable, reliable and transportation of material for the mining industry. The
statement says that the project mission is to develop:
“Reliable, cab-less and autonomous vehicles. Designed to improve profitability and safety for
transportation of materials within the mining industry.”
5.2 Function degradation
In order to generate chassis layout concepts, it is important to understand what components that
has to be considered and how they are related. Therefore, a function degradation was performed
to subdivide the vehicle tasks and functions into solutions and required components. The main
function to transport material gave rise to eleven subtasks, see Figure 14. Note that, in contrast
to manually driven trucks, there is no need of any cab, door, entry, interior or driver interface
which allows for many new chassis configurations. The complete function degradation can be
found in Appendix B.
Figure 14: Function degradation including eleven different sub-categories.
These subtasks require several components that were divided into three groups according to
Table 3. These groups were to be processed during three phases respectively in the concept
generation phase. Note that some components might be optional and there may be several
21
solutions to their task. Group 1 components are associated to the vehicle main attributes such
as load carrying capacity, turning radius, length and width. Group 2 components, and the tasks
giving rise to them, has a great impact on the chassis layout. Group 3 consists of components
with unknown specifications and requirements which thereby requires further investigation.
Table 3: Truck components divided into three categories, phase 1, phase 2 and phase 3.
Group 1
Axles Gearbox
Clutch Suspension
Crossmembers Transfer gearbox
Electric motor Propeller shaft
Engine Wheel brakes
Frame Wheels
Group 2
AdBlue tank Engine protective casing
Air intake Fan
Air tank Fuel tank
Air processing system Horn
Batteries Mudguard
Body Silencer
Bumper Steering system
Cooling system Subframe
Exhaust pipe Washer container
Group 3
Antennas Sensors
Electric computer units Side markings
Head and rear lamps Retro-reflectors
22
5.3 Product specification
The product specification is an important document that guides projects and establishes a solid
foundation for the concept generation phase. The specification was created from the project
description and the information acquired during the need finding and benchmarking process. It
presents quantified requirements and requests as well as a ranking of their importance. It is also
against this specification that the concepts were verified. In Table 4 below a summary of the
requirements are shown and the full product specification is found in Appendix C.
Table 4: Summary of product specification.
Requirements and requests Description
Compatible with loaders Requirements influenced by loaders. Such as loading height and
load carrying capacity.
Compatible with public roads Legal requirements.
Drivable in environment Defines the accessibility of the vehicle.
Easy to produce Body building and currently available components.
Fit in underground mines Dimensions required by underground mines.
High availability Describes requirements for maintenance.
Human friendly Communication to nearby personnel.
Legal Required laws and regulations have to be fulfilled.
Move material How the vehicle is supposed to function within the mine.
Productive Involves maintaining or improving the productivity. Such as
engine power and range.
Robust Requirements to sustain operation in the mining environment.
Safe Safety requirements concerning both vehicle and personnel.
23
6 Concept design
The final concept was generated through three phases addressing each of the component groups
presented in Table 3 respectively. Each phase generated, evaluated and selected solutions for
the specific parts and functions of each group, keeping the final function and layout in mind.
The first phase, presented in 6.2 Wheel configuration and powertrain, generated overall
concepts with focus on the frame, powertrain, suspension, axles and wheels. Concepts were
generated as sketches and setups in Vehicle Optimizer, a program created by Scania to analyse
parameters such as load distribution and turning radius.
In the second phase, described in 6.4 Bodywork and main components, more detailed concepts
were created through 3D-modelling in CATIA. The feasibility of the concept selected in phase
1 was also evaluated. The concept generation in phase 2 considered the components in group 2
in Table 3.
The third phase, presented in 6.6 Finalizing, considered the areas for sensors, electronic control
units, antennas, headlight placement and retroreflectors. The space for sensors and electronic
control units was roughly described by interfaces in the CATIA model as research on the
subjects was not completed.
The phases were initiated by identifying related requirements and requests, limiting factors and
possibilities to the addressed functions. The different possibilities were then combined into
concepts which were narrowed down and carried over to the next phase. As an example, after
each phase a basic concept was generated and two performance steps to the basic concept were
created during the first phase.
6.1 Technical specification
A technical specification is a document used by Scania to allow customers to configure their
truck to fit their demands instead of only offering fixed models. The chassis layout concept is
developed by altering existing components and creating new combinations within the technical
specification. This as well as introducing new components expands the technical specification.
Every concept generated from the specification does not have to fulfil both the underground
and open pit requirements. However, the technical specification should be able to offer choices
to fulfil both. In order to generate concepts a draft of a technical specification was created, see
Appendix D. The document accounts for all considered solutions, contained in a matrix, and
the combination of these solutions gives all possible concepts.
24
6.2 Wheel configuration and powertrain
The first phase addresses a section of the truck including suspension, axles, powertrain, side
members, crossmembers and wheels. The absolute majority of the trucks sold to the mining
industry by Scania are basic trucks with three to five axles. Therefore, and due to time
limitations, the project was narrowed down to only consider basic truck concepts with five or
less axles.
The generated concepts in Appendix E were analysed in Vehicle Optimizer. The application
uses simplified models to estimate many parameters of which load distribution, total load
carrying capacity and turning radius were evaluated. A Scania mining truck was used as
reference. The truck was specified with the maximum load carrying capacity of 12 tonnes on
each front axle and 42 tonnes over the bogie as shown in Figure 15. The truck was also specified
with a front axle moved forward by 50 mm which enhances load distribution and allows further
extension of the body as explained below. The result is a front axle distance of 1990 mm, a
wheel base of 4350 mm and 1450 mm between the axels in the bogie. The frame overhang is
840 mm and the body extends 270 mm after the frame end. The overall vehicle length is 8450
mm.
Figure 15: Reference truck used in Vehicle Optimizer.
6.2.1 Considered attributes and solutions
The related vehicle properties and requirements are length, width, load carrying capacity,
turning radius, supported driving and tipping directions, fuel consumption and ground clearance.
Whether the vehicle is drivable on public roads or not and to what extent the concept can be
realized with Scania’s bygglada are also important properties.
Load carrying capacity
The load carrying capacity is highly dependent on a good load carrying distribution. On the
reference truck and Scania’s mining trucks today, the centre of gravity when loaded is just in
front of the bogie, see Figure 15. Hence the majority of the load is carried on the rear axles.
25
The absence of the cab saves almost a tonne on the front axles and enables space to carry more
load. However, the density of the ore is greater than the weight per occupied volume ratio of
the cab. This drives the centre of mass forward if the body was to be extended towards the front
as shown in Figure 16. This results in poor load distribution which gives a lower load carrying
capacity. The maximum load of the front axles is thereby a limiting factor. In order to address
this issue several solutions were considered.
Figure 16: Cab-less truck with forward extended body.
One approach is to increase the maximum technical load of the front axles. However, this is
limited by the space under the engine, the steering mechanism and suspension. In discussion
with the axle, suspension and wheel development departments, NAA and RTCB at Scania it
was concluded that an increase to 14 tonnes maximum technical load is reasonable, see Figure
17. That is an increase of 2 tonnes per axle. This would require heavier front axles, stiffer
suspension and more durable and probably larger tires. Larger tires could limit the maximum
steering angle on the front most axle resulting in larger turning radius. Though this cannot be
evaluated at this point since that would require more information.
26
Figure 17: Cab-less truck with stronger front axles.
Another concept is to decrease total load on the front axles by also moving the second axle
forward. Discussions with RTCB resulted in a limitation of a 450 mm decrease of the axle
distance resulting in a distance of 1540 mm as shown in Figure 18. Note that the solution only
supports a small forward extension of the body. In this example the load on the front axles is
reduced by about a tonne but does not compensate fully for the forward shifted centre of mass.
Figure 18: Cab-less truck with shortened axle distances.
The solution could be achieved by shortening the suspension, which also would make it stiffer,
or with asymmetric suspensions, altering its configuration between the first and the second front
axle. Though an asymmetric suspension will give rise to steering errors and discussions with
RTCB resulted in a recommendation of the first alternative.
The load distribution could also be shifted towards the bogie by centring it under the load. This
could be achieved by extending the frame behind the bogie, see Figure 19. The greater rear
overhang would relieve the front axles but increases the risk of tip over when unloading. The
27
solution would also increase the volume capacity of the truck. Though, the truck becomes
increasingly sensitive with higher load density and a heavy duty truck should therefore have a
small overhang, making this option unsuitable.
Figure 19: Cab-less truck with greater overhang.
To allow the body to extend behind the bogie, without creating a large overhang over the last
rear axle, a steering supporting axle could be added. It would then be beneficial to also centre
the bogie by moving it forward, see Figure 20.
Figure 20: Extended, cab-less truck with support axle and centred bogie.
However, the main limit is the maximum angle and angular speed of the steering mechanism
for the supporting axle. None of the suggested solution above allow the whole cab to be replaced
by heavy payload, that is extending the body all the way to the front for transportation of ore
and stone. Instead the space could be used for mounting those components that today are
mounted on the frame. The overall weight of these components are less than the heavy load.
This would retain a lower load in the front of the truck and the centre of mass would remain
28
closer to the bogie. The solution might also simplify sensor placement, give greater ground
clearance and allow for smaller axle distances, since less components require space on the frame
between the wheels. The components would act as a counter weight when tipping the body,
lowering the risk of tip over when unloading.
Any new developed front axles positioned under the engine would be restricted by the available
space, limiting the maximum load carrying capacity. A more futuristic concept would therefore
be to extend the frame in front of the engine to enable stronger steering axles with dual wheels.
The concept cannot be built in Vehicle Optimizer but Figure 21 illustrates the wheel
configuration. The axles could possibly be placed in both the front and the rear resulting in a
symmetric wheel configuration with optimal load distribution when the body covering the truck
from the front to the rear. The axles should have a maximum technical load of 16.5 tonnes in
order for the vehicle to maintain the load carrying capacity. The concept would result in a longer
vehicle with a large wheel base which puts high demands on the frame and subframe.
Figure 21: Cab-less truck with front extended frame and steering axles.
However, the concept requires many new components that add to Scania’s bygglada while only
contributing to a small segment of trucks. This is contrary to Scania’s modular system and
highly undesired. Though if it would be found that the axles could be utilized by other types of
trucks or if autonomous mining trucks are sold in larger numbers than Scania’s mining trucks
today, the concept might be beneficial.
Safety
Safety is critical in the mining industry and some changes could contribute to the overall safety.
With a lowered centre of gravity, the risk for the truck to roll over would be less. With a heavy
front and a long vehicle, compared to body length, the risk of tip over would also be lower.
These two accident are usually caused by material not unloading properly and sticking to the
flat bed. A truck that only drives in one direction is also safer since it is clearly visible to
personnel in which direction the truck is driving.
Turning radius
The turning radius is mainly influenced by the steering angles and wheel base, at Scania
measured as the distance between the first steering axle and the first rear driven axle.
An effective way of decreasing the turning radius is to design a shorter truck. However, to keep
the truck length a steering supporting axle could be added at the rear allowing the non-steered
axles to move forward.
Another solution could be to have steering axles in both ends and with non-steering axles, if
any, positioned in the middle of the truck, Figure 21 shows an example. If the axles allow the
same steering angles as the front axles enables today, the effective wheelbase would in theory
29
be halved. The turning radius would be drastically decreased compared to a truck with non-
steering rear axles and could be as low as 8 meters. This could be achieved by making a
symmetric vehicle with the Y-shape in each end, allowing the existing front axles to be mounted.
Another way of decreasing the turning radius would be to enable larger steering angles. This
can be achieved by increasing the track width and thereby increasing the distance between the
wheel and the frame. This would also slightly increase truck stability. The solution would be
effective on the first steering axle, where the space between the wheel and the frame is narrow.
The disadvantage of the solution is that it would require new axles that would be illegal to drive
on public roads.
Driving directions
The vehicle could possibly drive in two directions and due to the autonomous driving, the
forward direction is arbitrary. Via a modification of the driveline and gearbox in particular, the
truck could even go in both directions in full speed. The autonomous driving also allows for
different steering. The truck could be front, rear or all wheel steered and even alter between
these in different situations and driving directions. Though, in order to gain sufficient traction,
the rear set of axles should be driven. This is especially important when the truck is loaded or
going uphill. This gives that a rear wheel steered concept requires axles that are both steering
and driving. It also implies that a concept with altering forward direction would benefit from
an all-wheel drive configuration.
Tipping directions
Side tipping does not put any special demands on the truck since the load usually is distributed
over several axles. In contrast, rear tipping tends to put a high pressure on the rear most set of
wheels and single wheels tend to dig into the ground. Hence, dual wheels or extra wide tires are
required on the end which the body tip about.
A considered solution to that problem was to equip the truck with stabilizers that would support
the single wheels when tipping over them. This might lengthen the unloading cycle time and
can be hard to fit if equipped in the front of the truck.
Though the unloading point for mine transportation trucks is in almost all cases known in
advance. This brings that the position and orientation of the vehicle can be planned and adjusted
to the unloading location. Hence there is no reason for a transportation vehicle to be able to tip
in more than one direction. Important is only that the concept is compatible with bodyworks
featuring either side tipping or tipping over one end. In the case of end-tipping it is beneficial
to allow tipping over the rear end that is not over the engine, since that does not require any
new components or solutions.
Length and width
The length of the truck is, in this phase, given by the length of the frame. However, the frame
must have enough space for frame mounted components and axles. The frame must also not
extend to far out on the end around which the body tip about, as discussed above. Another
dimensioning factor is the length between the supporting points on frame from the suspension.
Shorter axle distances and wheel base decreases the moment and stress experienced by the
frame.
The width of the truck, in this first phase, is given by the axles. Scania’s regular axles fit within
2500 mm which is the limit to be able to drive on all public roads. Scania also uses a special
30
rear supporting axle for mining applications that is 2600 mm wide. The axle is steering, has a
dual wheel setup and a mechanism bypassing the suspension to support the increased load when
tipping over the rear side. It is thereby assumed that the concept will be wider than 2500 mm if
an axle with this functionality is used.
Ground clearance
The ground clearance is given by several measures. One is height of the axle, illustrated in
Figure 22, which is limited by the wheel size.
Figure 22: Axle ground clearance.
A second measure is given by the lowest height of non-wheel and non-axle components, as
shown in Figure 23. The measure depends on the axle distances and height of the frame as well
as size and position of frame mounted components.
Figure 23: Ground clearance of frame mounted components.
Hence ground clearance increases with larger tires, higher or no frame mounted components
and a suspension configuration raising the frame.
Fuel consumption
The fuel consumption per transported tonne payload is mainly influenced by the choice of
powertrain. Hence the chassis layout may mainly influence the fuel economy by allowing
different powertrains such as different engines and hybrid drives. A full-electric vehicle
requires recharging, a slow process that cause much down-time. This is contrary to the
industry’s demand on up-time and availability. Therefore, the full-electric vehicle was rejected.
31
6.3 First concept selection
The first concept selection was performed by comparing the different solutions in a matrix, see
Appendix F. The first stage of the comparison was made by ensuring that each concept fulfilled
all related requirements. The second stage was based on a reference system. Where one of the
concepts which had the potential to fulfil all of the requests was set as a reference, with a score
of 3 in each criteria. All other concepts were scored against this reference, where 1 was the
lowest score and 5 was the highest. Each criteria score was multiplied with the weight
percentage of the corresponding request, where the weight percentage is based on how
important the request is. This gave a weighted score that was summed up to achieve a total
score for the concept. The top three concepts were then chosen for further evaluation.
During this evaluation a basic concept and two corresponding performance steps were selected.
A 3D mock-up of the basic concept was created in CATIA. An evaluation of the clearance
between the gearbox and the second front axle showed that the minimum allowed axel distance
between the front axles was 1640 millimetres. This to be able to remove the gearbox from
beneath the truck. The suggested axle distance of 1540 millimetres was thereby rejected and
changed to 1640 millimetres. The winning basic concept is evolved from a Scania 8x4 basic
tipper. The technical specification was then updated to include solely the required solutions.
New features to Scania are stronger front axles with 14 tonnes maximum technical load and the
smaller front axle distance.
The new front axle concepts require shorter and stiffer leaf springs and more durable tires
dimensioned to fit within 1640 millimetres and to be able to withstand the 14 tonnes of nominal
load. Also the axles, steering, frame and subframe requires dimensioning for the heavier load.
6.3.1 Basic concept
The concept example is one of the most basic models generated from the technical specification
with two steering axles in the front and a bogie in the rear, see Figure 24.
Figure 24: Wheel configuration and suspensions.
Performance
The concept, together with the available performance steps, fulfils all related requirements and
four out of six requests. The supported gross vehicle mass is 70 tonnes, the outer track radius
was estimated to just under 10 m and the frame has a length of 7471 mm. The length of the
frame enables bodies long enough, to keep the vehicle overall height under 2.8 m while holding
enough volume to carry the available payload. The layout concept allows rear, front and all-
wheel drive configurations as well as two-way driving in full speed. The concept is also
1031 1640 2510 1450 840
32
compatible with the highest, at Scania today available, frame configuration which enables a
high ground clearance.
6.3.2 Performance steps
If higher load carrying capacity is requested, it could be achieved with an extra axle. For this,
two concepts were considered.
To maintain the manoeuvrability and turning radius the extra axle should be added as a steered
supporting axle behind the bogie, keeping the wheelbase of 4150 mm unchanged, see Figure
25. This would increase the load carrying capacity by 14 tonnes. The solution is currently used
in Scania’s 10x4*6 trucks in mining applications but have experienced some complications.
The axle also makes the truck illegal to drive on public roads.
Figure 25: First suggestion of performance step.
To maintain the vehicle width, the extra axle should be added as a third steered front axle, see
Figure 26. This would increase the load carrying capacity by 9 tonnes. To ensure that the axle
is not overloaded a smart air suspension would be used though this limits the maximum
technical load. This solution also increases the wheelbase to 5300 mm resulting in a kerb
radius of about 12 m corresponding to an increase of 2300 mm turning radius.
Figure 26: Second suggestion of performance step.
If several full speed-driving directions are requested the concepts could be equipped with a
special powertrain designed for this task. An all-wheel drive configuration would then be
preferred which is achieved via a transfer gearbox between the last front axle and the first rear
axle. Note that while driving with the bogie in front the vehicle will be rear wheel steered.
1031 1640 2510 1450 1350 840
1031 1640 1540 2120 1450 840
33
6.4 Bodywork and main components
The second phase addresses the bodywork, bumper, air tanks, air intake, exhaust treatment and
outlet, AdBlue tank, cooling system, steering systems, fuel tanks, batteries, mudguards, washer
tank, horn, air processing unit and the engine protective cover. This section of the truck is
related to all vehicle requirements and requests, found in Appendix C. Considered components
and solutions
Bodywork and unloading techniques
The main function of the body work is to hold and unload material. A method to unload material
without tipping is to push the load of the body with a piston, see Figure 27 or rolling belt.
Figure 27: Piston unloading material [32].
This method does not create the instability that might occur when tipping and the vehicle does
not require extra roof clearance in underground mines. There are also examples of where
hydraulic tipping is not needed. Instead the whole truck is tipped by an external mechanism,
see Figure 28. However, the solutions are not commonly used and experience at Scania
concludes that the system causes increased maintenance and down-time.
Figure 28: Tipping the whole truck [33].
The solution to tip the body is more reliable. Compare to non-tipping solutions in underground
applications, it has proved to be more cost efficient to create extra roof clearance at the
unloading locations.
34
Rear tipping is generally more robust, simple and less costly than side tipping. Though side
tipping is safer and quicker and requires less roof clearance. In order to enable both strategies
the body must have sufficient clearance to the surrounding components both to the rear and the
sides.
It is important that the body volume matches the load carrying capacity so that the maximum
possible pay load can be utilized while the truck is still not easily overloaded. Though the
density of the load is varying greatly. The minimum volume is thereby given by an
approximated average load density of mixed stone and ore of 2100-2600 kg/m3 [34]. To
increase or decrees the volume capacity for a given flatbed length, the body height or with can
be adjusted. These variations already exist on the market today. However, broadening the
flatbed makes the vehicle illegal to drive on public roads.
It is also important that the frame can withstand the stresses from the extra load and shifted load
distribution. This could be ensured by extending the subframe forward, a solution that is
allowed by the absence of the cab. The extra length would reduce stresses on the main frame
and could help support the extra load shifted towards the front. Another possibility would be to
strengthen the regular frame and body while removing the subframe. This would be beneficial
to get into underground mines as it would decrease the overall height.
A secondary function of the body is to protect the truck from falling rocks and dirt. The body
therefore often has a falling object protection system, FOPS, covering the cab. On a cab-less
truck the FOPS could cover sensitive components mounted in the front as well as the engine.
The FOPS often cover the cab and has a small inclination that prevents rocks from falling in
front of the vehicle, see Figure 29.
Figure 29: Falling object protection system [35].
However, the bodywork has the main influence on the vehicle overall height, which increases
with the FOPS. This could become limiting to the trucks ability to enter underground mines. A
body work for underground applications, with low clearance to the roof, would thereby
preferably have a FOPS without inclination or no FOPS at all. A removal of the FOPS would
greatly reduce the maximum height when tipping over the truck end.
35
Air intake
The performance of the high air intake, HAI, and its filter will be the same even if relocated as
long as it is kept high. This allows for the intake to be moved forward, kept on the right side of
the truck, into the space normally occupied by the cab as shown in Figure 30. The forward
position of the intake allows for a longer body which enables a greater volume and payload. As
well as shorter piping as the inlet to the engine is positioned right next to the HAI. The solution
would require new brackets and a new outlet, after the filter, adapted to a position in level with
the inlet of the turbocharger.
Figure 30: High air intake, forward position.
If a chamfered front is used, as discussed under Truck front nedan, the air intake could be
slightly angled in order to align with the truck front, as shown in Figure 31.
Figure 31: High air intake, angled forward position.
36
Exhaust and silencer
In case the vehicle is specified with a shortened front axle distance, the existing silencer
positions are no longer feasible. A solution is then to use a modification of the existing rear
position on 4626 mm of the silencer, moving it forward by 450 mm, resulting in position a) in
Figure 32. The solution only requires minor changes of the pipes and utilizes thereby Scania’s
existing bygglada to a high extent.
Figure 32: Silencer positions, illustrated by large silencers.
Another concept is to place the silencer where the cab used to be, either over the first front
wheel or the engine, position b) and c) in Figure 32. The current position of the silencer as well
as position a) is exposed to falling rocks and wheel loaders loading the truck. The altered
positions also allow for higher ground clearance and greater robustness as the component is less
exposed. The silencer could also be rotated in position b) and c) to gain a low inlet pointing
downwards and a high outlet pointing upwards. The solution would result in very short exhaust
pipes both to the inlet and from the outlet of the silencer while providing vertical exhaust. The
rotation would require minor changes of the silencer such as replacement of sensors and new
supports.
In comparison to position b), position c) shifts the carried payload and moves the centre of mass
slightly towards the rear which enhance load distribution. However, it uses more spaces in the
front that could be needed for sensors, ECUs and headlights. The close proximity to sensors
and ECUs would also require heat covers for isolation between these components and the
silencer. The position also complicates the design of brackets as it would have to be supported
by both sidemembers, creating complications when the sidemembers move relative to each
other. It would also slightly complicate the removal of the engine cover and thereby
maintenance.
The exhaust system is quite flexible. It is relatively easy to reroute and the exhausts could even
be led through the body. If a close cooperation with the body builders or if the body can be
strictly specified, the body could be used as the only exhaust outlet eliminating the need of a
vertical exhaust. The body could also be specified to allow both heating and non-heating of the
freight and still lead the exhausts through the body. Whether the body is heated or not is
especially important when transporting material in very cold conditions where the freight might
stick to the body due to refreezing water, melted by the body heater.
37
Fuel and AdBlue tanks
Mining trucks are today refuelled during driver change, something that does not take place with
an autonomous vehicle. This gives the opportunity to operate continuously for a whole shift, 22
hours, if the truck can carry enough fuel. Though the fuel is heavy. A Scania truck today carries
typically 200 to 400 litre of diesel and refuels one or two times a day. The weight of the filled
fuel tanks is about 225 to 450 kilograms. The necessary time to refuel varies but, if refuelled
by a fuel truck, it can be done within ten minutes. In order to operate a whole 22 hour shift
without refuelling, the truck would have to carry about three times the amount of fuel, that is
600 to 1200 litres corresponding to 675 and 1350 kg. This would reduce the load carrying
capacity by 450 to 900 kilograms and thereby the productivity by 0.9 % to 1.8 %, given a
payload of 50 tonnes. The saved time for not refuelling twice a day saving six to ten minutes
each time, the up-time would be increased by about 0.95 % to 1.5 %, assuming operation during
22 hours per day. This indicates that the impact on increasing the fuel capacity to avoid
refuelling, might be small and not certainly positive. However, a more thorough analysis would
be needed for each case and customer. The stop for refuelling could also allow for the vehicle
to be cleaned and a quick inspection of the vehicle to be carried out. This might ease
maintenance and prevent unplanned disruption.
The position and type of fuel tanks should ease refuelling while maintaining a high ground
clearance and robustness. Placing the fuel tanks in the old cab space would enable the greatest
ground clearance but would also complicate refuelling. If the regular position on the frame is
used, the G tanks should be chosen for maximum ground clearance. The short wheelbase of
4150 mm in combination with the tighter front axle distance allows for 200 and 300 litre G-
tanks, as shown in Figure 33 and Figure 34. That is a maximum of 600 litres on the frame if
dedicating all available space on the frame to the fuel.
Figure 33: 200 G Fuel tanks right and left hand position.
38
Figure 34: 300 G Fuel tank left hand position.
Scania’s Euro 5 and 6 engines allow the AdBlue tank to be placed anywhere on the chassis. But
if the tank is used together with a euro 4 engine the AdBlue-pump cannot be placed above the
injection to the silencer as it will disturb the ratio between exhausts and AdBlue. However, the
Euro 3 engines do not use any AdBlue.
The maximum amount of fuel and AdBlue held by the truck should be in such proportion so
that they are depleted and require refilling at the same time. As an example, an AdBlue tank
with a nominal volume of 47, 80 or 105 litre is enough for 650, 1250 or 1600 litres of diesel
respectively. Ongoing development will also allow a combination of up to two tanks.
For ground clearance one or two 500 S, 47 litre tanks are preferably chosen due to its small size
and high position on the frame. The considered positions are shown in Figure 35. Another
solution would be to place the AdBlue tank in the front in the previous cab space. This would
free more space on the frame, reduce the amount of tubing and result in greater robustness.
Though refilling of the tank would most likely be more difficult since the tank would be
positioned higher above the ground. Another special installation could be to place the tank in
the lower right corner. This space is unoccupied in a heavy duty mining vehicle since it is the
position of the air inlet filter for the frontal air intake. Mining vehicles are preferably specified
with a high air intake.
Figure 35: AdBlue tank positions.
39
Air tanks
The air tanks hold 10 to 36.5 litre of pressurised air and there are several available mounting
positions, resulting in many possible combinations and available solutions. Some pressure tank
positions are suitable for both rear and front axle brakes while some positions only are suitable
for either of them. At least one of the tanks should be positioned close to the brakes in order to
prevent delay while braking.
The front axle air tanks, shown in Figure 36, should hold 50-60 litres and would typically
consist of two 30 litres air tanks. The most suitable positions would be above either front wheel
or in the triangular space between the mudguards.
Figure 36: Front axel air tanks positiones.
The rear axle air tanks, shown in Figure 37, holds 80-105 litres of pressurised air, normally
divided on several 15 or 30 litres tanks. Suitable positions are both on the outside and inside of
the frame. Though tanks mounted on the inside are less vulnerable and leaves space for other
frame mounted components.
Figure 37: Rear axle air tanks positiones.
One solution to gain 105 litres of air would be to mount two 30 litres air tanks on top of each
other on the outside of the frame and three 15 litres tanks in between the frame side members.
The two 30 litres tanks could also be replaced with one 30 litres air tank on each side, in the
triangular area between the front axle mudguards. Another option is to place one 30 litres air
40
tank in the triangular area between the front axle mudguards and have one of the 15 litres tanks
mounted inside the frame.
Air Processing System
The air processing unit, APS, has not been repositioned, see Figure 38. The size of the APS is
determined by how much compressed air is used by the truck. If the compressed air will be used
to clean the sensors as well as braking the vehicle, another dryer will probably be needed. This
would increase the APS size. With an increased size the layout may be changed as two dryers
does not fit with the XL wheel house.
Figure 38: Air processing system, left corner position.
Horn
The universal way of signalling that the vehicle is ready for loading or notice someone of the
vehicle approaching is to sound the horn. As the wheel loaders will be driven by workers and
other humans will work around these trucks the component is kept even in the autonomous
concept, see Figure 39. With the cut corners in the front the horn must be repositioned, however
it is still positioned in the front left corner.
Figure 39: Horn, repositioned left corner.
41
Steering system
In contrast to trucks steered by a driver, the absence of the steering wheel and steering wheel
shaft enables the steering servo to be placed on either side of the truck, disregarding left or right
hand traffic, as shown in Figure 40. This could enable more optimal and compact packaging of
components in the vehicle front. Dump trucks in mining applications does not utilize the frontal
air intake, FAI. This leaves a great amount of space in the right front corner of the vehicle where
the FAI filter otherwise is positioned. A suggested layout concept would thereby be to use the
right hand side position of the steering mechanism, design for left hand traffic.
Figure 40: Steering servo left and right hand positon.
The steering could either use hydraulic or electric servo steering. The hydraulic system is used
in the trucks today and the electric system is under development. The hydraulic system is
controlled by an electric motor which acts as the driver input. The main advantage of the electric
system is that it can operate when the engine is shut off and that it is more robust since it does
not use a hydraulic system.
As the steering wheel shaft to the cab is removed it is possible to relocate the steering
mechanism. This enables more optimum positioning relative the suspension which could result
in a decrease of steering errors.
Engine protective casing
The cab, on regular trucks, work as an engine protective casing and a noise reducer. Since the
cab is removed a new casing should be developed. With an engine protective casing it is
possible to lead the generated heat from the engine away from the silencer, which would greatly
improve its working condition. The new concept could originate from the existing floor of the
R- or S-cab, as shown in Figure 41, depending on the space requirements of the cooler in the
front. To avoid unnecessary tilting or removal of components during maintenance the casing
should cover solely the engine and be possible to remove or tilt without dismounting
components mounted above the front wheels.
42
Figure 41: Engine cover from R-cab floor.
Cooling system
With the driver removed there are possibilities to improve the current cooling of the engine
compared to Scania’s mining trucks today. This could be achieved by installing the biggest
cooler available, seen in Figure 42, or even develop a larger cooler.
Figure 42: Large engine cooler.
The increased payload will most likely demand more cooling, which could be solved with the
biggest fan currently available. According to experts at RTGR, the cooling system should be
able to support driving in two directions if the truck is equipped with the biggest cooler and fan
available. If needed it would also be possible to develop new side mounted coolers to further
enhance the cooling for multi-directional driving.
43
Truck front
The truck does no longer need the boarding steps to the cab which allow the outer turning radius
to be improved by cutting the corners of the front and bumper as shown in Figure 43. This
would require either a relocation or redesign of the head lamp installation. The opportunity
seems feasible and promising but requires further investigation.
Figure 43: Front interface layout with cut corners.
Washer tank
Even though the driver is removed there is still a need for a washer tank, see Figure 44. There
are sensors that will need a clear protective screen. Depending on how often the protective
screen in front of the sensors have to be cleaned and how much washer fluid it requires the size
of the tank can vary.
Figure 44: Washer tank, left corner position.
44
6.5 Second concept selection
The second concept selection was performed as a selection and combination of several partial
concepts. An example of a truck, based on a basic 8x4 from concept selection one, featuring
the parts from the second concept selection is shown in Figure 45. The concept supports both
side and rear tipping bodies. The forward angled position of the high air intake was suggested
as well as position c) in Figure 32 of the silencer. The concept was equipped with two 200 G
tanks holding a total of 400 litres of fuel and the AdBlue tank was positioned on the outside of
the frame on the right hand side behind the fuel tank. The air pressure tanks for the front axles
were positioned over the front wheel on the left hand side together with the batteries. The rear
pressure tanks were positioned both within and on the outside of the frame behind the fuel tank
on the left hand side. The air processing unit, horn, washer tank and steering servo was kept in
their original positions in the left front corner. The engine was covered by the floor from an R-
cab and the corresponding cooler was used. Finally, an approximate model for a front with cut
corners was added.
In order to ease maintenance, the concept was also equipped with boarding steps between the
front mudguards as well as a catwalk on top of the subframe.
Figure 45: Example truck specified with parts from concept selection two.
The concept requires development of new brackets and variations on some existing components
as well as and mudguards for the second axle. The body building interface should be updated
to allow the flatbed and the subframe to extend further forward. The extended subframe would
support the increased load on the frame and front axles.
45
6.6 Finalizing
During this phase the focus was on assuring that there is enough space for sensors, antennas
and headlamps as well as electronic control units. This was done through discussions with
experts and employees within the different areas. The overall aim was to keep antennas and
sensors mounted on the chassis as it would be more complicated to integrate them into the truck
body since Scania does not build these.
Antennas
The vehicle to vehicle communication will be done by a combination of patch antennas and
dipole antennas. The placement of the antennas is currently being investigated but the
discussions held has concluded that there shouldn’t be any conflict between the current chassis
layout and the requirement of the sensors.
Electrical control units
To make the system more robust the electronic control units have been placed in a protective
casing in the front. The aim is to keep their working environment stationary with a certain
temperature and moisture to assure that they will work during the vehicles lifetime.
Headlamps
With the cut corners it's no longer possible to have the headlamps in the same position without
altering them. This together with the removal of the driver and absence of legal requirements
enables the option for different placements and configurations. When the driver is removed it
is possible that the lighting will be optimised for the cameras instead. One suggestion is to put
the headlamps next to the sensors to get a better illumination for the sensors as this would
minimise shadows.
Retro-reflectors
There will be people working around the autonomous vehicles, but to which extent is not clear.
Therefore, further investigation on safety measures have to be conducted. The placement of
retro-reflectors will depend on the need of visibility and placement of position lighting.
Sensors
There would be no space complications if the vehicle would use the current configuration of
sensors. The current configuration is a combination of cameras and radars providing a 360-
degree vision. If additional sensors would be needed or some sensors would have to change
position, there is several available positions in the front of the truck.
This configuration is suitable when the vehicle is driving in one direction. To drive in two
directions, both forward and backward, two fronts would be needed. The current rear positions
for sensors is not high enough for the road surface assessment. With two fronts only side tipping
is possible and the benefits of two-way driving does not outweigh the benefits from being
compatible with rear tipping flatbeds in terms of flexibility and productivity.
46
7 Final concept
As stated in 4.6 Market opportunities there are many advantages with an autonomous vehicle.
With the presented final concept, see Figure 46, additional advantages can be achieved by a
more optimized chassis layout. The performance of the concept as well as benefits and
drawbacks are described below.
Figure 46: Final concept.
Enhanced cooling capacity
As the cab is removed, the truck can be specified with a larger cooler. It is even possible to
develop bigger coolers to further enhance the cooling capacity. This is especially important
since the concept increases the load carrying capacity and thereby the powertrain and engine
load.
Greater ground clearance
The combination of larger tires, smaller and higher positioned frame mounted components as
well a shorter wheelbase results in high ground clearance, greater then Scania’s mining trucks
today. This increases flexibility and ensures production even under bad road conditions.
Greater range
The concept is able to carry more fuel than Scania’s mining trucks of the same size today. This
gives the possibility to reduce the need of refuelling which might raise up-time for some
customers and result in higher productivity and profitability.
Higher payload to weight ratio
With the cab removed and an overall shorter vehicle the vehicle weight is reduced. This
increases the payload to vehicle weight ratio which in turn decreases fuel consumption per
transported tonne, increases profitability and lowers environmental impact.
Increased payload
The development of stronger front axles and the new chassis layout results in an increase of
about 5 tonnes, around 10 %, payload compared to an 8x4 truck with maximum loaded axles.
This increases the productivity and profitability for the customer.
47
More robust component placement
Those components that today are mounted on the frame but in the final concept are placed above
the frame in the truck front has a lowered risk of being damaged. The risk of components being
hit by wheel loaders when the truck is loaded or damaged by stones lying on the road is
decreased. This in combination with the higher ground clearance results in more robust
component placement which could extend the maintenance cycle.
Optimized air in and outlet position
With the new position and orientation of the high air intake, HAI, and silencer there will be
much less piping. The in- and outlet of the engine is next to the HAI and silencer respectively.
The silencer will also be less affected by the heat radiated from the engine which results in
better operating condition for the silencer.
Public roads
The concept follows the same restrictions to the outer dimensions as Scania’s manual trucks on
the field today. This makes implementation of the concept where trucks are already present
easier as well as allowing the vehicle to be transported on public roads and simplifies
transportation between mining sites. It also enables further development of the concept for long
distance transportations on public roads and not only within the mine, once the legal
requirements regarding autonomous vehicles are in place.
Underground and open-pit compatibility
The same vehicle can be used in both underground and open-pit mines. The vehicle height is
about 2760 millimetres which is enough to enter underground mines with the lowest roof
clearance today. The only component that decides the vehicle height over 2.8 meters is the body.
By choosing the appropriate body the vehicle is able to operate in all mines. This could open a
new segment of the mining industry and expand Scania’s available market.
Simplified maintenance
Maintenance is eased by removal of the cab and by adding a catwalk on the subframe which
provides easy access to the chassis front. While fuel and AdBlue tanks are positioned for easy
access, the silencer and batteries are positioned to gain robustness which reduces the risk of
failure. The high utilization of Scania’s existing bygglada also favours maintenance since much
of the customer’s knowledge about Scania’s trucks is valid also for this autonomous solution.
Smaller turning radius
With a shorter wheelbase and cut front corners, the turning radius was decreased with about 0.6
meters corresponding to a 6 % reduction. With smaller turning radius it is easier to manoeuvre
on narrow roads and in tight underground mine tunnels which allows the customer to save
money by keeping roads and tunnels smaller.
Suitable for different applications
The final concept is not constrained to hauling applications. The body is the main deciding
factor on what application the vehicle will be applied to. The vehicles could be used in both
open pit and underground mines for transportation of ore and waste, of personnel and equipment
or as a water tank truck and much more.
Tip stability
The removal of the cab and shortening of the truck decreases the truck weight, especially in the
front, which increases the risk of tip over when unloading over the rear end. The tip cylinder
48
must be placed under rather than in front of the flat bed which further decreases stability.
Though it usually results in faster unloading.
Utilization of Scania’s bygglada
The concept utilizes the bygglada to a high extent as most components are carried over from
the manual trucks of today. This reduces the time for development and lowers the cost of the
vehicle.
49
8 Suggestions on new parts and modifications
To be able to produce this concept, some components would have to be modified or added. The
modifications are described in summary here and individually in detail below.
The concept requires development of new brackets for those components moved from their
standard positions. It also requires a new variation of the silencer adapted to the new rotation.
The exhaust pipes have to be rerouted and a new air outlet from the high air intake filter is
needed. The concept also requires a new truck front including redesign of external panels and
reconsideration of headlight positioning. Mudguards compatible with XL-wheels for the second
front axle should be developed in order to protect sensors from dirt and a cover for the engine
must also be developed. To utilize the available volume over the engine and front axles the
body building interface has to be redefined.
The concept could also benefit from a new higher mount for air tanks on the outer side of the
frame in order to gain maximum ground clearance though it is not mandatory. Whether the
higher mount, which adds variations to the bygglada, would be profitable is subject for further
investigation.
Air inlet and exhaust
The new silencers position requires the exhaust pipes to be rerouted. The piping is dependent
on the chosen solution, such as vertical exhaust or exhaust through the body. A new air outlet
from the high air intake filter is also needed in order to fit the new position.
Bodybuilding interface
The new layout enables more space for the body and a new body builder interface must be
established. The different possible specifications of the concept create variations of the interface.
The most influencing variations are engine and silencer type. A Euro 6, V8 engine and silencer
enables least space while a Euro 3 or less with a 13 litres engine or smaller gives most space
for the body.
Brackets
New brackets must be developed for those components that has been moved from their standard
positions of today. That is high air intake, silencer, front axle air tanks and batteries.
Engine protective casing
With the removal of the cab there is still a need for protection of the engine. As well as heat
and noise protection from the engine towards other components. The cover could originate from
the engine tunnel on the cab which has these functions and features.
Front
With the cut corners a new front has to be developed. The new sensor, electronic control unit,
antenna and headlight placement should be taken into account when designing the front as well
as their climate and cleaning systems.
Front wheel suspension
A new front wheel suspension, including leaf springs, axles, tires and steering mechanism, that
has a maximum technical load of 14 tonnes has to be developed. The suspension and tires must
also fit within 1640 millimetres axle distance.
50
Mudguards
To protect the sensors from dirt, mudguards for XL-wheels on second front axle are needed.
Though these could be built by the bodybuilder if Scania does not develop them.
Silencer
The new orientation of the silencer, and rotated 180 degrees around its Y-axis, requires a variant.
The new version includes altered sensor positions to ensure the right dosage of AdBlue into the
exhaust.
51
9 Discussion and conclusions
The project shows that Scania has the potential to develop a driverless and cables autonomous
truck for the mining industry with a few modifications of the bygglada. The suggested concept
would have better overall performance and in particular higher availability, higher flexabillity,
lower environmental impact and greater personnel safety while providing higher profitability
for the customer compared to the conventional solutions on the market today. However, the
suggested changes to the bygglada are based on what experts at each department at Scania
believe is possible. Thereby, to confirm that the concept is feasible further research and
development is required.
In order to be able to develop a concept for a whole autonomous truck within the project limits
some assumptions and delimitations were made.
Basic trucks or tractors
To limit the scope in the beginning of the project a sales analysis was performed. This showed
that the basic trucks accounts for the majority of the trucks sold for transportation within the
mining industry. With this analysis in mind tractors and trailers were ignored. These type of
trucks are currently being sold and are operating within the mining industry. A chassis layout
for autonomous tractors would be subject for further investigation.
Cabling and piping
During the project some knowledge about cabling and piping has been acquired. However, the
layout is not very dependent of these at this stage of the concept. Although the design minimizes
the piping by placing components as close to the source as possible. Many of the cables that are
routed to the cab are removed as they are for the driver. Even though there are more electronic
control units with autonomous driving it will most likely be a lesser or equal amount of cables.
Calculations
In order to be able to create a layout for a whole truck an overall knowledge was achieved.
However, there was no time for calculations on specific components as to evaluate how they
would be affected by the suggested changes. Instead an overall calculation of load distribution
was performed with Vehicle Optimizer and the feasibility of the suggested concepts was instead
assessed through discussions with experts on the different areas.
In order to simulate a cab-less truck in Vehicle Optimizer some estimations had to be done since
the programme is limited to chassis layouts including a cab. However, loads can be added or
subtracted directly to the front and rear axles respectively. The chassis concepts were thereby
specified with the smallest cab with an estimated weight of about 900 kg. The front axle load
was then compensated by a subtraction of 900 kg. However, the cab’s centre of gravity is not
located over the middle of the front axles. This creates a lever arm from the cabs centre of mass
to the front axle’s centre. The lever arm contributes towards an over estimate of the front axle
load and underestimated rear axle load. That is, the front axles might be relived more than 900
kg and the rear axles might experience an increased load which has not been taken into account.
On the other hand, not the whole cab is removed since some modified parts of the front are kept.
This gives that the weight of the removed components might be less than 900 kg and contributes
to an underestimate of the front axle load. These two errors partially cancel each other, resulting
in a smaller total error.
52
Vehicle Optimizer does also not allow the user to specify a body that extends further forward
then the cab. In order to evaluate the forward extension of the flatbed, the weight of the body
and the centre of mass for both body and load was adjusted to the corresponding weight and
position of a longer flatbed. These two workarounds fully simulate the forward extended body
in a load distribution analysis. When evaluating the flatbed volume relative to load density the
flatbed was simply specified with its correct length. This results in false load distributions on
the axles but the axle loads are not of interest in the volume and density analysis.
Another source of error to the load distribution analysis is that the exact weight of the different
components on the truck is unknown.
Customer needs
The list of customer needs was based on a four years old pre-study, performed in 2012. Some
of these needs could have changed and new could have emerged but there were no resources to
perform another study. Therefore, the ranking had to rely on a combination of the pre-study and
the competence of experts on Scania.
Dimensioning
When designing the vehicle, the most extreme case was used for dimensioning. The biggest
possible components were used, such as V8 engine, large Euro 6 silencer and cooling system.
If all of these components are able fit on the truck it is possible to use any smaller performance
step as well.
53
10 Future work
The possibility to increase the maximum technical load up to 14 tonnes on the front axles must
be further evaluated and confirmed through more thorough analysis of the whole chassis front.
The higher load carrying capacity increases productivity which is profitable for the customer
but the profitability for Scania must be evaluated. Development costs and other consequences
as well as benefits of the new performance steps has to be analysed. The new components and
performance steps might be useful in other applications than mining and autonomous vehicles.
Scania’s mining segment might also grow with the new technology and enhanced performance.
There is a new possibility to outcompete specialised mining transportation vehicle and the
ability to operate in low underground mines opens a new segment of the market. These factors
should all enhance the profitability for Scania.
The decreased front axle distance leaves little space for removal of the gearbox which
complicates maintenance. The extent of this problem for the future gearboxes must be made
clear and possible solutions to ease the procedure should be addressed.
The final concept is a basic concept designed for high density load such as ore and stone. The
performance steps on the wheel configuration presented in 6.3.2 Performance steps should be
able to utilize the component placements of the basic concept but this requires confirmation.
However, the component placement for a vehicle optimized for transportation of lighter
materials, such as coal, would differ from the final concept. Then volume capacity and vehicle
length may then become the dimensioning factors. In that case, the silencer could be kept on
the frame and behind the second front axle allowing the flatbed to extend over the engine,
batteries and pressure tanks, all the way to the high air intake and electronic control units in the
front. The author’s belief is that, aside from the already suggested changes to the bygglada, an
introduction of silencer position a) presented in Figure 32 on page 36, would allow for that coal
transportation concept. However, this requires further investigation.
Suggestion on different technical solutions to manage the increased load on the front axles has
been discussed during the project. One of these suggestions is a distributing suspension. The
solution could reduce the load variation on the axles and thereby lower the demands on
components in the chassis front. Another issue is that the increased maximum load on the
wheels might require larger tires. This could result in a decreased maximum steering angle and
thereby an increased smallest turning radius. Though there is no requirement on comfort which
could enable new types of tires with sufficient load carrying capacity and smaller or equal size
as Scania’s larger tires today. Another solution could be to implement the idea of wider track
with, allowing for larger steering angles. The performance of the steering mechanism could
also be enhanced since it does no longer need to connect to the steering shaft. The steering servo
would then be moved relative to the suspension into a more optimized position. However, that
would create new performance steps only applicable on cab-less trucks.
Regarding safety, a big question is how the vehicle is supposed to be turned off when something
goes wrong. It must be possible to force a shut down but how would that be performed? Does
this require an emergency stop button on the vehicle? And how would it then be accessed when
the vehicle is driving and does this requirement change the chassis layout? These questions
must be answered and requires further studies.
54
The positioning of the sensors, radars, headlights and antennas have to be re-evaluated once
their requirements are known. Depending on the sensor, electronic control unit, and antenna
placement and on how big their respective protective casings with climate control has to be, the
layout might have to be changed slightly.
55
Bibliography
[1] Scania CV AB, “Scania Global transportation solutions,” September 2012. [Online].
Available:
http://www.scania.com/global/Images/ScaMiningSolutions_201209_enxx1599652_tcm
306-382603.Pdf. [Accessed 09 02 2016].
[2] A. Ekström and J. Sörensen, “Förstudie om Autonoma Fordon i Gruvindustrin,”
Scania, Mälardalens högskola, Södertälje, 2012.
[3] K. Ulrich and S. Eppinger, Product Design and Development, 5th edition, New York:
McGraw-Hilton Education, 2012.
[4] E. Bakhtavar, K. Shahriar and K. Oraee, “A Model for Determining Optimal Transition
Depth over from Open-pit to Underground Mining,” 2008.
[5] “Mining-technology,” [Online]. Available: http://www.mining-
technology.com/contractors/project/marston/marston4.html. [Accessed 22 February
2016].
[6] “Viewpoint Perspective on modern mining,” [Online]. Available:
http://viewpointmining.com/article/going-underground-in-china. [Accessed 22
February 2016].
[7] Boliden, “Welcome to Boliden Aitik,” 09 August 2012. [Online]. Available:
http://www.boliden.com/Documents/Press/Publications/Broschures/Aitik_folder_eng_
web.pdf. [Accessed 22 February 2016].
[8] P. J. Coleman and J. C. Kerkering, “Measuring mining safety with injury statistics:
Lost workdays as indicators of risk,” Journal of Safety Research, p. 11, 2007.
[9] M. Zhang, V. Kecojevic and D. Komljenovic, “Investigation of haul truck-related fatal
accidents in surface mining using fault tree analysis,” Safety Science, p. 12, 2014.
[10] J. M. Patterson and S. A. Shappell, “Operator error and system deficiencies: Analysis
of 508 mining incidents and accidents from Queensland, Australia using HFACS,”
Accident Analysis and Prevention, p. 7, 2010.
[11] M. McCann and M.-T. Cheng, “Dump Truck-Related Deaths in Construction, 1992-
2007,” American journal of industrial medecine, p. 8, 2012.
[12] J. Gustafsson and D. Karlsson, “Mining industry guidelines,” Scania, Södertälje, 2009.
[13] M. Edstam, “Performance Specification - Dump truck in Mining,” Scania, Södertälje,
2013.
[14] M. Wågberg, Interviewee, [Interview]. 22 February 2016.
56
[15] Alban Cat, “AlbanCat Earthmoving Equipment,” [Online]. Available:
http://www.albancat.com/new/earth-moving/. [Accessed 18 February 2016].
[16] “Atlas Copco Gruvtruckar - Dieseldrivna,” [Online]. Available:
http://www.atlascopco.se/sesv/products/last--och-transportutrustning/3506192/.
[Accessed 18 February 2016].
[17] Scania CV AB, “Scania to supply 200 trucks to leading Indian mining company,”
Scania, [Online]. Available: http://www.scania.com/group/en/scania-to-supply-200-
trucks-to-leading-indian-mining-company/. [Accessed 07 06 2016].
[18] D. M. o. I. a. t. Environment, “European Truck Platooning Challenge 2016,” [Online].
Available:
file:///C:/Users/ggrkbt/Downloads/Storybook%20European%20Truck%20Platooning%
20Challenge%202016.pdf. [Accessed 31 05 2016].
[19] DAF Trucks N.V. Corporate Communication Department, Rutger Kerstiens, “Self-
driving trucks tested on Dutch highway - NL Times,” 10 02 2015. [Online]. Available:
http://www.nltimes.nl/2015/02/10/self-driving-trucks-tested-dutch-highway/.
[Accessed 2 Mars 2016].
[20] “DAF and TNO demonstrate ‘EcoTwin’,” DAF, [Online]. Available:
http://www.daf.com/en/news-and-media/articles/global/2015/q1/27-03-2015-daf-and-
tno-demonstrate-ecotwin. [Accessed 16 Mars 2016].
[21] “Youtube - World premier Mercedes-Benz Future Truck 2025,” 23 September 2014.
[Online]. Available: https://www.youtube.com/watch?v=uwr26H80w44. [Accessed 2
Mars 2016].
[22] Mercedes-Benz, “Mercedes-Benz The long-haul truck of the future,” [Online].
Available: https://www.mercedes-benz.com/en/mercedes-benz/innovation/the-long-
haul-truck-of-the-future/. [Accessed 2 Mars 2016].
[23] “Mercedes, The long-haul truck of the future,” [Online]. Available:
https://www.mercedes-benz.com/en/mercedes-benz/innovation/the-long-haul-truck-of-
the-future/. [Accessed 16 Mars 2016].
[24] KOMATSU Corporate Communications, “Komatsu, Press Release, Rio Tinto activated
Komatsu's autonomous haulage system in Australia,” 25 December 2008. [Online].
Available: http://www.komatsu.com/CompanyInfo/press/2008122516111923820.html.
[Accessed 2 Mars 2016].
[25] KOMATSU Corporate Communications, “Komatsu, Press Release, Komatsu
announces autonomous haulage project with Rio Tinto,” 18 January 2008. [Online].
Available: http://www.komatsu.com/CompanyInfo/press/2008011815580104227.html.
[Accessed 2 Mars 2016].
57
[26] Komatsu, “Komatsu Magazine Down to earth,” November 2009. [Online]. Available:
http://www.komatsu.com.au/AboutKomatsu/NewsAndPublications/D2E/Issue%2052/
DownToEarth-52.pdf. [Accessed 2 Mars 2016].
[27] “Komatsu, Rio Tinto activated Komatsu's autonomous haulage system in Australia,”
[Online]. Available:
http://www.komatsu.com/CompanyInfo/press/2008122516111923820.html. [Accessed
16 Mars 2016].
[28] Scania CV AB, “CombaT Basic,” [Online]. Available:
http://combat.scania.com/basic/main_combat_basic.html. [Accessed 29 February
2016].
[29] J. R. -. C. A. I. Erlemeier, “Air Tank Layout PD,” Scania, Södertälje, 2016.
[30] Scania CV AB - RTMP, “Technical specification - General,” Scania CV AB,
Södertälje, 2015.
[31] D. Bergqvist, Interviewee, [Interview]. 19 02 2016.
[32] Caterpillar, “Rental Articulated Trucks 740B,” [Online]. Available:
http://www.cat.com/en_US/products/rental/equipment/articulated-trucks/three-axle-
articulated-trucks/17748745.html. [Accessed 06 10 2016].
[33] AB Seals, “What is Hydraulic Truck Unloader ?,” [Online]. Available:
http://www.abseals.co.in/BLOG/?p=23. [Accessed 06 10 2016].
[34] Scania CV AB - Göran Svensson, “Technical Product Data,” Scania CV AB,
Södertälje, 2009.
[35] Scania CV AB, “Scania delivers 150th tipper to BGR Mining,” [Online]. Available:
https://www.scania.com/group/en/scania-delivers-150th-tipper-to-bgr-mining/.
[Accessed 10 06 2016].
A.1
Appendix A
A.1 GANTT-Table and scheme
A.2
B.1
Appendix B
B.1 Function degradation schemes
B.2
B.3
C.1
Appendix C
C.1 Product specification
Ge
ne
ral re
qu
irem
en
tO
pe
n-p
it req
uire
me
nt
Sp
ec
ializ
ed
for u
nd
erg
rou
nd
req
uire
me
nt
Mo
ve m
ate
rial
≤ 1
10
00
mm
.≤
10
00
0 m
m.
≥ 5
70
mm
.≥
39
0 m
m.
Unlo
ad
ove
r front o
r rea
r ed
ge
≤ 4
20
0 m
m.
≤ 2
70
0 m
m.
-≤
34
00
mm
.
-≤
70
00
mm
.
Ea
sy to
pro
duce
Hig
h a
vaila
bility
Le
ga
l
Ge
ne
ral re
qu
es
tsS
pe
cific
req
ue
sts
Prio
rityO
pe
n-p
it req
ue
st
Sp
ec
ializ
ed
for u
nd
erg
rou
nd
req
ue
st
Sm
all o
ute
r turn
ing
rad
ius
2≤
90
00
mm
.≤
80
00
mm
.
Hig
h g
round
cle
ara
nce
on fra
me
mo
unte
d c
om
po
ne
nts
2≥
63
0 m
m.
≥ 4
40
mm
.
Re
duce
bo
dy c
ycle
time
1
Mo
re e
fficie
nt lo
ad
ing
and
unlo
ad
ing
2
Ab
le to
he
at fre
ight
1
Pro
fitab
leL
ow
fue
l co
nsum
ptio
n2
Co
mp
atib
le w
ith b
igg
er lo
ad
ers
2≥
60
tonne
s L
CC
. -
Lo
w m
axim
um
tipp
ing
he
ight
2≤
70
00
mm
.≤
56
00
mm
.
Fitt in
und
erg
round
min
es w
ith lo
w ro
of c
lea
rence
1 -
he
ight ≤
28
00
mm
.
Le
ng
th fo
r pub
lic ro
ad
2
Wid
th fo
r pub
lic ro
ad
2
He
ight fo
r pub
lic ro
ad
2
Pre
stig
ious
Ro
bust a
pp
ea
rance
3
Ea
sy b
od
y build
ing
2
Ea
sy to
rea
lize3
Pro
vide
custo
me
r fea
ture
sS
tora
ge
ca
pa
bility
1
No
te: 3
= h
ighe
st p
rio th
en 2
and
1 e
qua
ls lo
we
st p
rio.
Ea
sy to
pro
duce
Fit in
und
erg
round
min
es
Susta
in m
ud
, dust a
nd
dirt
Ro
bust c
om
po
ne
nts
.
Hum
an frie
nd
ly
Fa
ste
r tha
n c
om
pe
titors
.
Go
od
driva
bility
Co
mp
atib
le
≤1
20
00
mm
.
Co
mp
atib
le w
ith p
ub
lic ro
ad
s
≤ 4
00
0 m
m.
≤ 2
55
0 m
m.
De
fine
d b
od
y build
ing
inte
rface
.
Pro
tective
co
vers
on a
ll se
nsitive
co
mp
one
nts
. Dura
ble
ma
teria
ls.
Ea
sy b
od
y build
ing
Ea
sy to
cle
an a
nd
rep
air
Pro
duct s
pecific
atio
n
Sa
fe
Driva
ble
in e
nviro
nm
ent
Ro
bust
Pro
ductive
≥ 3
0-4
0 L
pre
ssure
d a
ir pe
r axle
.
Tip
pin
g h
eig
ht ≤
80
00
mm
.
Suffic
ient e
ng
ine
po
we
r
Fa
st u
nlo
ad
ing
Suffic
ient ra
ng
e
Fit d
iffere
nt e
ng
ine
s.
Pe
rform
a fu
ll op
era
ting
cyc
leP
ote
ntia
l to s
tart, lo
ad
, transp
ort, u
nlo
ad
and
drive
ba
ck.
Pa
rkE
quip
pe
d w
ith a
pa
rkin
g b
rake
sys
tem
.
One
ea
sy to
acce
ss s
tora
ge
bo
x.
Cle
arly s
ho
w w
he
n d
riving
, bre
akin
g, tu
rnin
g, re
vers
ing
, unlo
ad
ing
etc
.
If ICE
po
we
rtrain
: ab
le to
fit Sca
nia
Euro
3-6
eng
ine
s.
So
und
-pro
ofin
g o
f eng
ine
and
ge
arb
ox.
Avo
id tu
rn a
round
.
Sp
ace
for h
ybrid
drive
.
Utilize
Sca
nia
's b
ygg
lad
a to
a h
igh e
xtent.
No
n-c
ha
ng
ing
.
Sup
po
rt 36
0 d
eg
ree
s vis
ion a
round
the
truck. S
om
e b
lind
sp
ots
ma
y exis
t.
Unkno
wn
Sup
po
rt dire
ctio
na
l lights
.
Sup
po
rt sid
e m
ark
ing
lights
.
All s
ensitive
or c
rucia
l co
mp
one
nts
co
vere
d. D
ura
ble
ma
teria
ls o
n e
xterio
r.
Effe
ctive
bra
kin
g
Sp
ec
ific re
qu
irem
en
t
Avo
id T
ip-o
ver
Go
od
se
nso
r visio
n a
nd
co
mm
unic
atio
n
Suffic
ient lig
htn
ing
for c
am
era
s
Ind
ica
te d
riving
dire
ctio
n
Vis
ible
Susta
in fa
lling
rocks a
nd
hits
from
sid
e, fro
nt a
nd
rea
r.
Susta
in h
igh te
mp
era
ture
rang
e a
nd
we
ath
er
Ne
w c
om
po
ne
nts
must s
usta
in -4
0 to
50
de
g C
els
ius a
nd
diffe
rent w
ea
the
r.
At le
ast a
s g
oo
d a
s H
AI.
Eq
ua
l or fa
ste
r tha
n re
ar tip
pin
g.
Ma
ximum
2 re
fue
ls p
er d
ay.
Inta
ke
of c
lea
n a
ir
Suffic
ient o
ute
r turn
ing
rad
ius
Suffic
ient g
round
cle
ara
nce
on a
xles
Ste
era
bility
≥ 2
3%
loa
d o
n s
tee
ring
axle
s.
≥ 3
00
mm
.
Suffic
ient g
round
cle
ara
nce
on fra
me
mo
unte
d c
om
po
ne
nts
"Wa
terp
roo
f". Ea
sy to
acce
ss a
ll co
mp
one
nts
.
Unlo
ad
ove
r front o
r rea
r ed
ge
and
sup
po
rt sid
e tip
pin
g.
Co
mp
atib
le w
ith to
da
ys
infra
stru
ctu
re
Pro
ductive
min
imum
35
tonne
s.
sup
po
rt 23
m^3
bo
die
s.
Suffic
ient L
CC
Suffic
ient vo
lum
e
Suffic
ient lo
ad
ing
he
ight
Lo
w m
axim
um
he
ight
Lo
w m
axim
um
tipp
ing
he
ight
Acce
pta
ble
no
ise
leve
l
Co
mm
unic
ate
inte
ntio
ns
Fulfil le
ga
l req
uire
me
nts
Ke
ep
the
freig
ht a
ga
inst th
e b
od
y unfro
zen.
D.1
Appendix D
D.1 Technical Specification - Draft 0
Technical specificationType Basic Articulated
Vehicle width ≤ 2,55m >2,55m
Vehicle length ≤ 12m >12m
Vehicle height ≤ 4m <2.8m
Wheel configuration 6x4 8x4 10x4*6 10x8*6 8x6*4 12x12*8 8x8*/8 10x4*8 10x8*8 10x6*6 ?
Propulsion
Wheels Small Medium Large
Powertrain ICE Electric Hybrid
Gearbox Yes
Differential Yes
Propeller shaft Yes
Clutch Yes
Middle drive Yes No
Exhaust pipe Vertical (long) Vertical (short) Middle Side Rear Through body None
Store energy Fuel tank Battery Fuel tank & Battery
Accept energy Pantograph None
Air intake + filter FAI HAI Side None
Cooling system Front Side Front & Rear None
Silencer / SCR Yes No
SCR tank Yes No
Hub reduction gear Yes No
Stop / slow / hold vehicle
Air tank Yes
Braking Drum
Retarder Yes No
Exhaust brake Yes No
APS Yes
Compressor Yes On ICE
Parking brake system Yes
Carry
Frame Y Double Y Extra long Y Extra short Y
Suspension Air Leaf
Axles Front Rear Support Steered bogie
Join frames Crossmembers Boxes
Subframe Yes No
Hold material
Body Non-removeable Removeable
Drain freight Through body Side Rear Front None
Non-freeze Yes No
Unload material
Unload Tip front Tip side Tip rear
PTO Yes
Start
Starter battery Yes No
Navigate
Lighting Headlamp
Sensors + casing Yes
Steering Draglink EST
Antennas Yes
Electric control units Yes
Power steering + pump Yes No
Avoid vehicle damage
Protective casing (engine) Yes
Bumper Yes
Mudguard Yes No
Avoid personnel injury
Visibility Side-markings Rearlamp Retro reflectors
Horn Yes
E.1
Appendix E
E.1 Wheel configuration concepts
Steering front axle
Steering driven front axle
Steering front axle with double mounted
wheels
Steering driven front axle with double
mounted wheels
Driven bogie
Non-driven bogie
Non-driven supporting axle
Driven support axle
Non-driven steering support axle
Driven steering support axle
Truck stabilizers
Engine and gearbox
Electric motor
Frame Y-shape
Frame straight
NOTE: Drawings are not to scale
.
E.2
E.2 Concept 1 – Tight wheel setup
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
10x4 78 ton 9.9 m 8.5 m 2.55 m
Pros
High LCC
Cons
No space for frame mounted components
E.3
E.3 Concept 2 – Tight wheel setup, steering rear axle
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
10x4*6 80 ton 8 m 8 m 2.60 m
Pros
Small turning radius
High LCC
Cons
Wide, not legal on public roads
No space for frame mounted components
E.4
E.4 Concept 2.2 – 2-way driveable, tight wheel setup, steering rear axle
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
10x4*6 80 ton 8 m 8 m 2.60 m
Pros
Small turning radius
High LCC
Driveable in two directions
Cons
Wide, not legal on public roads
No space for frame mounted components
E.5
E.5 Concept 3 - Tight wheel setup, enhanced load carrying capacity
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
12x4*8 92 ton 9.9 m 9.1 m 2.60 m
Pros
Very high LCC
Cons
Wide, not legal on public roads
No space for frame mounted components
Note
Performance step on Concept 1 and Concept 2
E.6
E.6 Concept 5 – Two way driving
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
10x4 78 ton 9.9 m 8.5 m 2.55 m
Pros
May tip in 2 directions
Drivable in 2 directions
Cons
Tipping cycle over front may be slower due to deployment of stilts
Alternating between front and rear wheel steering when changing driving direction
E.7
E.7 Concept 6 – Two way driving
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
12x10 78 -92 ton 9.6 m 10 m 2.55-2.60 m
Pros
May have very high LCC
Drivable in 2 directions
Cons
Front wheel steered in both directions
E.8
E.8 Concept 7 – Two way driving
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
12x8 80 -108 ton ~9 m 11 m 2.55-2.60 m
Pros
May have very high LCC
Drivable in 2 directions
May tip in 2 directions
Electric drive for alternated driving direction
Regenerative breaking downhill
May crab (generate lateral acceleration without generating yaw)
Cons
Very long
E.9
E.9 Concept 8 – Two way driving
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
8x8 56 -84 ton ~7.7 m 9 m 2.55-2.60 m
Pros
Drivable in 2 directions
May tip in 2 directions
May crab (generate lateral acceleration without generating yaw)
Cons
E.10
E.10 Concept 9 – Stronger front axles,
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
10x4 80 ton 10,2 m 9,2 m 2.55 m
Pros
Cons
Requires stronger front axles
E.11
E.11 Concept 10 – Stronger front axles, symmetric
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
12x8 90 ton 10,2 m 11 m 2.55 m
Pros
Very high LCC
Drivable in 2 directions
Cons
Requires stronger front axles
Only supports side tipping
Very long
E.12
E.12 Concept 11 – Stronger front axles, symmetric, front tipping
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
12x8 90 ton 10,2 m 11 m 2.55 m
Pros
Very high LCC
Drivable in 2 directions
Front / side tipping
Cons
Requires stronger front axles
Very long
May slow down unloading time
E.13
E.13 Concept 12 – Symmetric; Hybrid; Side-tipping
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
12x8 90 ton 8,2 m 9,5 m 2,5 m
Pros
High LCC
Drivable in 2 directions
Uses Y-frame
Possibly hybrid
Cons
Requires stronger front axles
Only supports side tipping
Long vehicle
E.14
E.14 Concept 13 – Single wheel; Side-tipping; Large volumes
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
10x4 62 ton 8,2 m 10,2 m 2,5 m
Pros
Good turning radius
Able to transport large volumes
Could possibly be hybrid with “double Y”
Side mounted components
Cons
Need stronger front axles for higher LCC
Side-tipping only, unless very high tipping height is allowed.
E.15
E.15 Concept 14 – Rear steering;
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
10x6*6 78 ton 9.9 m 8.5 m 2.55 m
Pros
Side tip / Front tip
Drives both directions
Only known components
Cons
Rear steering
No frame mounted components
E.16
E.16 Concept 15 – Rear / Side-tipping; Small turning radius
Wheel
configuration
Max technical
load
Kerb
radius
Approximate
length
Width
8x6*4 66 ton 8,2m 7,1m 2,5m
Pros
Very good turning radius
Able to side tip / rear tip
Cons
Need supports to rear tip
Lower LCC
F.1
Appendix F
F.1 First concept selection
Priority Open-pit request Weight
1. 2 ≤ 8000 mm 12,12%
2. 1,5 ≥ 700 mm 9,09%
3. 2 12,12%
4. 2,5 15,15%
5. 2,5 ≥ 60 tonnes LCC 15,15%
6. 1,5 9,09%
7. 1,5 9,09%
8. 3 18,18%
100%
Green: Winning concept
Yellow: Available concept
Red: Does not fulfil all requirements
Note Note Note
1. 3 0,4 9,9 m 4 0,5 8 m 4 0,5 8 m
2. 3 0,3 no fr.m. comp. 3 0,3 no fr.m. comp. 3 0,3 no fr.m. comp.
3. 3 0,4 No 3 0,4 No 4 0,5 Yes
4. 3 0,5 No 3 0,5 No 3 0,5 No
5. 3 0,5 78 ton GVM 3 0,5 80 ton GVM 3 0,5 80 ton GVM
6. 3 0,3 8,5 m 3 0,3 8 m 3 0,3 8 m
7. 3 0,3 2500 mm 3 0,3 2600 mm 3 0,3 2600 mm
8. 3 0,5 New f.susp. 3 0,5 New f.susp. 3 0,5 New f.susp.+gerabox
3,00 3,12 3,24
Note Note Note
1. 3 0,4 9,9 m 3 0,4 9,9 m 4 0,4 9,6 m
2. 3 0,3 no fr.m. comp. 3 0,3 no fr.m. comp. 3 0,3 no fr.m. comp.
3. 3 0,4 No 4 0,5 Yes 3 0,4 No
4. 3 0,5 No 3 0,5 No 3 0,5 No
5. 4 0,6 92 ton GVM 3 0,5 78 ton GVM 4 0,6 92 ton GVM
6. 3 0,3 9,1 m 3 0,3 8,5 m 3 0,3 9,6 m
7. 3 0,3 2600 mm 3 0,3 2550 mm 3 0,3 2600 mm
8. 2,5 0,5 New f.susp. 2 0,4 New f.susp.+stilts 1 0,2 New f.susp.+steer.ax.
3,06 2,94 2,85
Note Note Note
1. 3 0,4 9 m 4,5 0,5 7,7 m 2 0,2 10,2 m
2. 2 0,2 Fr.m. comp. 2 0,2 Fr.m. comp. 2 0,2 Fr.m. comp.
3. 3 0,4 No 4 0,5 Yes 3 0,4 No
4. 4 0,6 Yes 3 0,5 No 3 0,5 No
5. 5 0,8 100 ton GVM 3 0,5 84 ton GVM 3 0,5 80 ton GVM
6. 2 0,2 11 m 3 0,3 9 m 3 0,3 9,2 m
7. 3 0,3 2550 mm 3 0,3 2550 mm 3 0,3 2550 mm
8. 2 0,4 New steer.ax.+frame 2 0,4 New steer.ax.+frame 3 0,5 Stronger front axles
3,09 3,03 2,79
Note Note Note
1. 2 0,2 10,2 m 2 0,2 10,2 m 4 0,5 8,2 m
2. 2 0,2 Fr.m. comp. 2 0,2 Fr.m. comp. 3 0,3 No fr.m. comp.
3. 3 0,4 No 4 0,5 Yes 3 0,4 No
4. 3 0,5 No 3 0,5 No 3 0,5 No
5. 4 0,6 90 ton GVM 4 0,6 90 ton GVM 4 0,6 90 ton GVM
6. 2 0,2 11 m 2 0,2 11 m 2 0,2 9,5 m
7. 3 0,3 2550 mm 3 0,3 2550 mm 3 0,3 2550 mm
8. 3 0,5 Stronger front axles 3 0,5 Stronger front axles 3 0,5 New fr.susp.
2,85 2,97 3,18
Note Note Note
1. 4 0,5 8,2 m 3 0,4 9,9 m 3 0,4 8,2 m
2. 2 0,2 Fr.m. comp. 3 0,3 no fr.m. comp. 2 0,2 fr.m. comp.
3. 3 0,4 No 4 0,5 Yes 3 0,4 No
4. 3 0,5 No 3 0,5 No 3 0,5 No
5. 2 0,3 60 ton GVM 3 0,5 78 ton GVM 2 0,3 66 ton GVM
6. 2 0,2 9,5 m 3 0,3 8,5 m 3 0,3 7,1 m
7. 3 0,3 2550 mm 3 0,3 2500 mm 3 0,3 2500 mm
8. 4 0,7 None 3 0,5 New f.susp. 3 0,5 New f.axles
2,97 3,12 2,76
Hybrid drive
-
≤12000 mm
≤ 2550 mm
Utilize Scania's bygglada to a high extent
Concept 10 Concept 11 Concept 12
Concept 13 Concept 14 Concept 15
Concept 2.2
Concept 3 Concept 5 Concept 6
Concept 7 Concept 8 Concept 9
Concept 1 Concept 2
Length for public road
Width for public road
Easy to realize
Specific requests
Small outer turning radius
High ground clearance on frame mounted components
More efficient loading and unloading
Underground request
≤ 7300 mm
Low fuel consumption
Compatible with bigger loaders
≥ 440 mm
Avoid turn around.
TRITA AVE 2016:54
ISSN 1651-7660
www.kth.se
