Application of OpenModelica 1.12.0 for the Simulation of Mobile...

Application of OpenModelica 1.12.0 for the Simulation of Mobile Machinery

Linköping, 05/02/2018

OpenModelicaWorkshop 2018

Volker Waurich

Endowed Chair of Construction Machines

Outline

1. automation of a wheel loader

2. pile model

3. virtual sensors

4. operator control

5. wrap-up

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outline

AUTOMATION OF A WHEEL LOADER

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wheel loader operation

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automation of a wheel loader

• effective earth-moving dependsstrongly on operator skill level

• potencial for energy saving, increase in productivity, costreduction

• cutting and filling the bucket iscrucial

automation of a bucket filling

process

considerations

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automation of a wheel loader

F

α

bucket trajectory tire slip and wear performance

hardware setup

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automation of a wheel loader

CAN BCAN C

CAN D

CAN A

DAQ

ECU VKM

ECU HM

ECU FA

ECU MS

ECU AH

lidar process controladditional equipment

simulation setup

Linköping 05/02/2018 Simulation of Mobile Machinery slide 7

automation of a wheel loader

wheel loadermechanics and hydraulics

analyticalpile model

virtual 3D environment

process control

PILE MODEL

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analytical pile model

• 2D-model in the centre plane of bucket

• analytical computation of component forces

• F_cut = f(cutting depth);

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pile model

F_load

F_cut

F_downhill

F_friction

F_bottom

bucket

pose

cutting

depth,

intersection

area

forces,

loaded

mass,

contour

persistent contour

• pile surface must be persistent between loading cycles

• segmentation of surface

• enter segment: compute cutting depth

• leave segment: move contour, add load

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pile model

pileHeight[i] := min(pileHeight[i],bucket.z);

not in continuous models (online minimum problem)

persistent contour

• discrete behaviour with sampled time or state events is not efficient

• realtime criteria

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pile model

intersec = getExtIntersection(pile, bucket.x, bucket.z, time);

external C-model

VIRTUAL SENSORS

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3D-perception by distance measurement

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virtual sensors

Lidar: TOF-measurements oflaser beam

detection of angle of reposeand distance to pile Velodyne VLP-16

3D-lidar in unity

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virtual sensors

• comprehensive 3D world in unity

• virtual lidar using raycast() - bunch

• Velodyne VLP16 style UDP package

3D-environments in Modelica?

• coupling of unity with Modelica model

• model sends pose of sensor mounting

• sensor pose moves lidar gameObject

• lidar gameObject sends distance data

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virtual sensors

OPERATOR CONTROL

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operator model

• to accomplish driving tasks, working cycles

• emulate real operator

• algorithm for automated functions

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operator control

task,

perceptionoperator

model

actuator

signals

operator model

• modelling approach: discrete state machine

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operator control

operator control

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operator control

• target speed of cylinders , target wheel drive

WRAP-UP

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summary

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wrap-up

• OpenModelica is feasible to model mobile machinery (i.e. 3D mechanics, hydraulics, control)

• Modelica lacks comprehensive 3D-modelling and interaction

• tool-coupling to 3D-simulation software is a straightforwardpossibility to interact with 3D-worlds

OpenModelica achievements

• improvements with external C (Windows) enhance system simulations with hardware, networks and virtual

sensors

• important library improvements with OM 1.12.: OpenHydraulics and M_DD

hydraulic drive simulation and external tool coupling

• synchronous and state-machines operator control and process logic modelling

• 3D visualization

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wrap-up

outlook

• better 3D modelling in OM (live 3D models?)

• closer interaction with 3D-tools

• wheel-ground models

• multiple, persistent soil interaction

• collision detection

• hardware-in-the-loop (realtime!)

• ECU-coupling

• HMI-App design

• IoT interfaces (MQTT)

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wrap-up

IMU via CAN in OMEdit

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Thank you for your attention.

Thank you OM-developers for your support.

Volker Waurichvolker.waurich@tu-dresden.de