ANNEX V

VERIFYING AIR DRAG DATA

1. DEFINTIONS

...

2. INTRODUCTION

...

3. AIR DRAG

3.1 This Annex sets out the test procedure for verifying air drag data.

The air drag resistance force is calculated in VECTO by

Fair=Cd A cr(vveh)∗ρair ,ref∗vveh

2

2

where:

Fair = air drag [N]

Cd Acr (vveh) = product of drag coefficient (Cd) by cross sectional area (Acr) including vehicle speed dependent influence of crosswind [m²]

ρair, ref = air density at reference conditions1 1.188 [kg/m³]

vveh = vehicle velocity [m/s]

The function Cd Acr (vveh) is calculated in VECTO by

1 Reference conditions are defined with 20°C, 1000mbar and 50% humidity

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Cd A cr (v veh)=1

2 π∗vveh2∫

0

2π

[Cd Acr (0 )+∆Cd Acr ( β ) ] ∙ vair (vveh ,α)2 dα

and:

vair=√ (vwind∗cos α+vveh)2+( vwind∗sin α )2

β=arctan (vwind∗sin (α )

v veh+vwind∗cos (α ))

Fig. 1: Geometrics of air flow and vehicle speed

where:

Cd Acr (0) = product of drag coefficient (Cd) by cross sectional area (Acr) for zero crosswind conditions as determined by the constant speed test procedure [m²]

ΔCd Acr (β) = generic dependency of air drag on yaw angle [m²] (see section 3.12)

β = yaw angle between air flow direction and driving direction [rad]

α = angle between wind direction and driving direction [rad]

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vwind = average wind velocity for European conditions = 3 [m/s]

The constant speed test procedure shall be applied to determine the product of drag coefficient by cross sectional area for zero crosswind conditions Cd Acr (0). The measurement data of this test shall be entered into the VECTO-CSE tool which determines Cd Acr (0) as input for VECTO. Alternatively the family concept can be applied to determine the Cd Acr (0) for a certain HDV configuration.

3.2 Constant speed test

During the constant speed test the driving torque, vehicle speed, air flow velocity and yaw angle shall be measured at two different constant vehicle speeds (low and high speed) under defined conditions on a test track.

The execution of the constant speed testing shall meet the following requirements:

3.3 General requirements

3.3.1 Test track

i. Shape / Geometry of test track:The test track shall be either a

a. Circuit track (drivable in one direction*):with two measurement areas on each straight part, approximately parallel to each other (max. deviation: 20  degrees);*at least for the misalignment correction of the mobile anemometer the test track has to be driven in both directions (>=5 laps)or

b. Circuit track (drivable in both directions):with one measurement area (or two with the above named max. deviation);or

c. Straight line track (drivable in both directions):with one measurement area;

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ii. Track surfaceThe test track shall consist of high quality asphalt or concrete. The surface shall be flat, clean, dry and free of obstacles or wind barriers that might impede the measurement of the running resistance (see also viii).

iii. Lengths of measurement area and measurement sectionsThe measurement area(s) consists of at least one measurement section and a stabilization section. Each measurement section shall have a length of 250 m with a tolerance of ± 3 m. The first measurement section of a measurement area is preceded by a stabilization section to stabilize the constant speed & constant torque. The stabilisation section shall have a length of minimum 125 m. The test track layout has to enable that the vehicle enters the stabilisation section already with the intended maximum vehicle speed during the test. As the data evaluation considers separate data blocks for each measurement of 250 m length, useable measurement area lengths are multiples of 250 m added to the stabilization section length.

iv. Shape of the measurement sectionThe measurement section and the stabilization section have to be a straight line which can be passed without correctional steering.

v. Slope of the measurement sectionSlope variations on the measurement section shall not lead to velocity and torque variations above the thresholds specified in 3.3.2.

vi. Side inclination of the measurement sectionThe side inclination shall not exceed 2 degrees.

vii. Selected standstill areaThere shall be a selected standstill area on the test track where the vehicle can be stopped to perform the zeroing and the drift check of the torque measurement system (torque sensors and or other relevant equipment e.g. amplifiers). This area shall have a maximum slope of 1 percent and a maximum side inclination of 2 degrees. The location of the standstill section shall enable a coast down of the vehicle to a complete stop.

viii. Distance to roadside obstacles and vertical clearance

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There shall be no obstacles within 5 m distance to both sides of the vehicle. Safety barriers up to a height of 1 m with more than 2.5 m distance to the vehicle are permitted. Any bridges or similar constructions over the measurement sections are not allowed. The test track shall have enough vertical clearance to allow the anemometer installation on the vehicle as specified in 3.5 viii.

3.3.2 Thresholds for variation of torque and vehicle speed

High speed testSpeed variation threshold [km/h]:

(v¿¿hms ,avrg−0.3km /h)≤ v hm, avrg ≤(vhms, avrg+0.3 km /h)¿

where:vhms,avrg = average of vehicle speed per 10 s measurement section [km/h]vhm,avrg = 1 s moving average of vehicle speed [km/h]

Torque variation threshold [Nm]:

(T ¿¿hms , avrg∗0.9)≤T hm ,avrg ≤ (T¿¿hms , avrg∗1.1)¿¿

where:Thms,avrg = average of Tsum per 10 s measurement section [Nm]Tsum = TL+TR; sum of corrected torque values left and right wheel

[Nm]Thm,avrg = 1 s moving average of Tsum [Nm]

Low speed testSpeed variation threshold [km/h]:

(v¿¿lms , avrg−0.5 km /h)≤ v lm, avrg ≤(v¿¿l ms , avrg+0.5 km /h)¿¿

where:vlms,avrg = average of vehicle speed per Xms seconds measurement section

[km/h]vlm,avrg = moving average of vehicle speed with Xms seconds time base

[km/h]Xms = time needed to drive 25 meter distance with low speed [s]

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Torque variation threshold [Nm]:

(T ¿¿ lms , avrg∗0.9)≤T lm ,avrg ≤ ¿¿)

where:Tlms,avrg = average of Tsum per Xms seconds [Nm]Tsum = TL+TR; sum of corrected torque values left and right wheel

[Nm]

Measurement data which do not meet the thresholds as specified above are automatically excluded in the data evaluation by VECTO-CSE.

3.3.3 Ambient conditions

i. The ambient conditions shall be measured with the equipment specified in 3.5.

ii. The ambient temperature shall be in the range of 0°C to 25°C. This criterion is checked by VECTO-CSE based on the signal for ambient temperature measured on the vehicle. This criterion only applies to the low speed – high speed - low speed sequence but not to the misalignment test and the warm-up phases.

iii. The variation of the ambient temperature during the low speed – high speed – low speed sequence shall not exceed 3°C. This criterion is checked by VECTO-CSE based on the signal for ambient temperature measured on the vehicle.

iv. The ground temperature shall not exceed 40°C. This criterion is checked by VECTO-CSE based on the signal for ground temperature measured on the vehicle. This criterion only applies to the low speed – high speed - low speed sequence but not to the misalignment calibration and the warm-up phases. It is recommended to perform the constant speed tests during cloudy conditions or during night time.

v. Weather conditions

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The weather shall be completely dry during the low speed – high speed - low speed sequence and during the misalignment calibration. The road surface shall be completely dry during the low speed – high speed - low speed sequence to provide comparable rolling resistance coefficients. A limited amount of precipitation during warm-up is allowed.

vi. WindThe wind conditions shall be within the following range:Average wind speed: ≤ 5 m/s (Bft. 3) (average over the full measurement section)Gust wind speed: ≤ 8 m/s (Bft. 4) (1 second moving average)Average yaw angle (β) (average over full measurement section; after application of boundary layer correction):

≤ 3 degrees for high speed tests≤ 5 degrees during misalignment calibration

The validity of wind conditions is checked by VECTO-CSE based on the signals recorded at the vehicle. Measurement data collected under conditions exceeding the above named limits are automatically excluded from the calculation.

3.4 Installation of the vehicle

i. The vehicle shall be measured without payload. ii. The front height and slope of the truck and standard trailer / box shall be

adjusted to meet the conditions corresponding to a standard laden vehicle as good as possible.

iii. The minimal distance between cabin and semi-trailer / box shall be in accordance with manufacturer requirements.

iv. The trailer setup shall be as defined in Annex XXX.v. The vehicle shall be equipped with tyres meeting the following demands:

Lowest rolling resistance available for the application; (A label ,alternatively B-label tyres)

Shaved tyres with a maximum thread depth of 4 mm. Tyres inflated to the highest allowable pressure

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For the pilot phase the tyres shall be stored to allow for retesting of vehicle (purpose of round robin testing)

vi. The axle alignment shall be within the manufacturer specifications.vii. Free rotation of wheels shall be given. Check disk brakes for inadvertent

contact friction after instrumentation of the vehicle (max. 20Nm per wheel).

3.5 Measurement equipment

The calibration of all measuring instruments and systems shall be traceable to national (international) standards. The measuring instruments and systems shall comply with the linearity requirements given in Table 7 of Annex 4 to UN/ECE Regulation No 49.06. The linearity verification shall be done as required by internal audit procedures, by the instrument manufacturer or in accordance with ISO 9000 requirements. If not specified differently below, the accuracy of the measurement equipment shall be such that the above named linearity requirements are not exceeded.Additional requirements for verification of repeatability, hysteresis, etc. to be further specified.

i. TorqueThe direct torque at all driven axles shall be measured with one of the following measurement systems:

a. Hub torque meter

b. Rim torque meter

c. Half shaft torque meter

System requirements:

Non linearity: < ± 6 Nm

Repeatability: < ± 3 Nm

Hysteresis: < ± 15 Nm

Measurement rate: ≥ 20 Hz

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The recorded torque data shall be corrected for the instrument error determined by the supplier.

T L=T Lr∗f TLie+f TLd

T R=T Rr∗f TRie+ f TRd

where:

T L = corrected torque left wheel [Nm]

T R = corrected torque right wheel [Nm]

T Lr = torque meter reading left wheel [Nm]

T Rr = torque meter reading right wheel [Nm]

f TLie = torque meter left - instrument error correction factor [-]

f TRie = torque meter right - instrument error correction factor [-]

f TLd = drift correction factor left torque meter [Nm]

f TRd = drift correction factor right torque meter [Nm]

ii. Vehicle speedThe vehicle speed is determined by VECTO-CSE based on the CAN-bus front axle signal which calibrated based on eitherOption a) a reference speed calculated by a delta-time from two fixed opto electronic

barriers (see iv) and the known length of the measurement section(s) or Option b) the ground speed signal of a differential GPS (DGPS) or alternatively a

delta-time determined from the position signal of a DGPS and the known length(s) of the measurement section(s)

For the final vehicle speed calibration the data recorded during the high speed test are used.

iii. Engine speed or cardan shaft speed

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The CAN engine speed signal is used together with the transmission ratios (gears for low speed test and high speed test, axle ratio) to calculate the rotational speed of the wheels at the driven axle. Accuracy requirements:

Engine speed: ± 2 rpm (t.b.d.)

Cardan speed: ± 2 rpm (t.b.d.)

Update rate: ≥20 Hz

Verification methods to be defined

iv. Opto-electronic barriersThe signal of the barriers is used for triggering begin and end of the measurement section and the check of the vehicle speed signal (see ii). The measurement rate of the trigger signal has to be greater or equal to 100Hz.

v. GPS systemfor position measurement:Required accuracy: Position: < 3m 95% Circle of Error Probable

Update rate: ≥ 5 Hzoptional for vehicle speed calibration and position measurement:Differential GPS system (DGPS)Required accuracy: Position: t.b.d.

Update rate: 100 Hz

vi. Stationary weather stationThe system shall be a calibrated weather station with registration of ambient conditions (temperature, pressure, humidity).Average measurement values shall be recorded at least once every 5 minutes.Required accuracy: Temperature: ± 1° C

Humidity: ± 5 %RHPressure: ± 1 mbar

Installation position:The meteorological instrumentation should be positioned adjacent to one of the measurement areas.

vii. Temperature transducer for ambient temperature on vehicle

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Required accuracy: Temperature: ± 1° CInstallation position:Install the thermocouple on the pole of the mobile anemometer. The sensor shall be shielded by a tube (synthetic material, e.g. water pipe; diameter approx. 50 mm; length approx. 80mm), the tube middle axis parallel to the vehicle longitudinal axis. The installation height shall be 20 to 30 mm below the mobile anemometer.

viii. Mobile anemometerSystem to measure air flow conditions (air flow velocity and yaw angle between total air flow and vehicle longitudinal axis).Required accuracy: Air speed: ± 2 % of actual reading

Yaw angle: ± 1 degreeThe anemometer shall be calibrated in a specified facility in accordance with the zero air speed and wind tunnel test procedures described in ISO 16622. A focus shall be put on the air speed range of 20 to 33 m/s and the β-range of ±7 °.The mobile anemometer shall be installed on the vehicle in the prescribed position:

X position: truck: front face of the semi-trailer or box-body;bus/coach: in the 2nd fourth or 3rd fourth of vehicle length

Y position: plane of symmetry Z position: installation height above the vehicle shall be one third of total

vehicle height

The alignment of the instrument shall be done as exact as possible using geometrical/optical aids. Any remaining misalignment is subject to the misalignment calibration.

Misalignment calibration:

The remaining misalignment of the anemometer shall be determined by calibration tests on the proving ground (see 3.8).

ix. Pressure transducer for tyre pressure (preliminary provision for the pilot phase)

Required accuracy: Pressure: ± 0.1 barInternal direct tyre pressure sensors shall be used. Further requirements t.b.d.If applied for later legislation: T.b.d whether VECTO-CSE shall process separate values for each tire?

x. Proving ground temperature (preliminary provision for the pilot phase)

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The temperature of the proving ground shall be recorded on vehicle by means of a contactless IR sensor. Required accuracy: Temperature: ± 2.5 °C

Update rate: ≥ 1 HzThe IR sensor shall be calibrated to the emissivity of the proving ground. Further provisions on calibration procedure to be added, refer to ASTM E2847?

3.6 Measurement signals and data recording

The following table shows the requirements for the measurement data recording and the preparatory data processing for the input into the VECTO-CSE tool. A detailed description of the requested data formats, the input files and the evaluation principles can be found in the technical documentation of the VECTO-CSE tool. The data processing shall be applied as specified in 3.10.

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Signal Column identifier Unit Measurement rate Remarks

Vehicle class code [-] 1 - 17 for trucks, 21 - 23 for buses

Vehicle configuration [-] "rigid" or "tractor" for truck/tractor&trailer configuration

Vehicle test mass [kg] Actual mass during measurements

Wheels inertia [kg m2] Rotational inertia of all wheels

Axle ratio [-] Axle transmission ratio

Gear ratio high speed [-] Transmission ratio of gear engaged during high speed test

Gear ratio low speed [-] Transmission ratio of gear engaged during low speed test

Anemometer height [m] Height above ground of the measurement point of installed anemometer

Vehicle height [m] Maximum vehicle height

Vehicle width [m] Vehicle width (without side mirrors)

Gear box type [-]Manual or automated transmission: “MT_AMT”, Automatic transmission with

torque converter: “AT”

Time <t> [s] since daystart - -

Ambient temperature <t_amb_stat> [°C] Stationary weather station

Ambient pressure <p_amb_stat> [mbar] Stationary weather station

Relative air humidity <rh_stat> [%] Stationary weather station

Trigger signal used [-] 1 = trigger signal used; 0 = no trigger signal used

Measurement section ID [-] user defined ID number

Driving direction ID [-] user defined ID number

Heading [°] Heading of the driving direction

Length of the measurement section [m] -

Latitude start point of section

Longitude start point of section

Latitude end point of section

Longitude end point of section

Measurement section configuration

Input CSE-tool

Vehicle data file

Ambient conditionshigher than 1 averaged value per 5 minutes

- -

- -

standard GPS: minimum 5 digits after decimal separator; DGPS: minimum 6 digits after decimal separator[mm.mm]

continued

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Signal Column identifier Unit Measurement rate Remarks

Time <t> [s] since day start 100 Hz rate fixed to 100Hz; time signal used for correlation with weather data and for check of frequency

(D)GPS latitude <lat> [mm.mm] ≥ 20 Hz

(D)GPS longitude <long> [mm.mm] ≥ 20 Hz

(D)GPS heading <hdg> [°] ≥ 20 Hz

(D)GPS velocity <v_veh_GPS> [km/h] ≥ 20 Hz not used in analysis if opto-electronic barriers are used

Vehicle velocity <v_veh_CAN> [km/h] ≥ 20 Hz raw CAN bus front axle signal

Air speed <v_air> [m/s] 4 Hz raw data (instrument reading)

Inflow angle (beta) <beta> [°] 4 Hz raw data (instrument reading); "180°" refers to air flow from front

Engine speed <n_eng> [rpm] ≥ 20 Hz -

Torque meter (left wheel) <tq_l> [Nm] ≥ 20 Hz

Torque meter (right wheel) <tq_r> [Nm] ≥ 20 Hz

Ambient temperature on vehicle <t_amb_veh> [°C] 10 Hz

Trigger signal <trigger> [-] 100 Hzoptional signal; required if measurement sections are identified by opto electronic

barriers (option "trigger_used=1")

Tyre temperature <t_tire> [°C] ≥ 1/3min average value; optional signal

Tyre pressure <p_tire> [bar] ≥ 1/3min average value; optional signal

Proving ground temperature <t_ground> [°C] ≥ 20 Hz signal recommended for the pilot phase

Validity <valid> [-] - optional signal (1=valid; 0=invalid);

primary torque calibration (y=kx+d) to be done in data capturing system (i.e. before import into VECTO CSE)

standard GPS: minimum 4 digits after decimal separator; DGPS: minimum 5 digits after decimal separator

Input CSE-tool

Measurement data file (fixed data input rate: 100 Hz)

Table 1: Measurement data

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3.7 Constant speed test procedure

The constant vehicle speed test shall be conducted with a maximum velocity span between the measurement of mechanical resistance (low speed) and total running resistance (high speed).

The target speed of the low speed testing shall be a constant velocity of 10 - 15 km/h.

The target speed of the high speed testing shall be a constant velocity of:

Trucks: 85 – 90 km/h

Coaches: 90 – 100 km/h

Construction vehicles and city busses: 85 - 90 km/h or speed 5 km/h below maximum possible speed (if maximum speed is below 85 km/h)

The average vehicle speed recorded in each dataset2 shall not deviate more than 5 km/h from the relevant target speed. The vehicle speed shall meet the speed variation thresholds (see 3.3.2).

The testing shall be performed according to the following sequence:

i. Install the torque meters on the driven axles of the test vehicle and check the installation and signal data according to the manufacturer specification.

ii. Check the drive-wheels for proper rotation with installed torque meters and half shafts (wheels off the ground; manually rotating the wheel; without heavy points). The torque required to rotate the wheels shall not exceed 20Nm.

iii. Documentation of relevant general vehicle data for the Testing Logbook (see 3.9).

iv. For the calculation of the acceleration correction by the VECTO-CSE tool the actual vehicle weight shall be noted. Therefore, measure the total mass of the vehicle or if applicable compute the mass with the values of the previous measurement and the fuel consumption. The actual vehicle weight can be calculated based on the last weighing by

reducing the mass by 0.25 kg per meanwhile driven kilometre adding 100 kg per additional vehicle occupant

2 A „dataset“ refers to the data recorded during a single measurement section.

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adding 0.83 kg per each additionally tanked litre of fuel

v. After finalisation of the constant speed test the average vehicle mass during the measurement sequence shall be noted in the testing logbook (see 3.9) and specified in the VECTO-CSE input data.

vi. Check tyres for the maximum allowable inflation pressure and document pressure values and ambient temperature.

vii. Prepare the opto-electronic barriers at the measurement section(s) or the DGPS reference station (whatever is applicable).

viii. Mount the mobile anemometer on the vehicle and control the installation, position and orientation. A misalignment calibration test has to be performed every time the anemometer has been mounted newly on the vehicle (see 3.5 viii).

ix. Check the data registration of all relevant measurement signals.

x. Start engine to pre-condition the vehicle (idling without parking brake).

xi. Check the vehicle setup regarding the height and geometry. Adjust the height of the semi-trailer to the target value if necessary.

Any additional explicit setup prescriptions required? (e.g. positions of mirrors, roof spoilers, …)

xii. Warm-up phase

Drive the vehicle minimum 90 minutes at the intended high speed to assure that the tyres reach a constant pressure and temperature level.The warm-up phase can be used to perform the misalignment calibration test (see 3.5 viii).

xiii. Standstill phase for zeroing / drift check for torque meters

Bring the vehicle to a standstill on the selected standstill area (see 3.2 vii) of the test track. Lift the instrumented axle(s) off the ground. The vehicle shall be slowed down carefully and rolled out for the last meters, with free clutch / neutral gear and engine switched off. Perform the zeroing of the amplifier reading of the torque meters.

The standstill phase shall not exceed 10 minutes.

xiv. Drive another warm-up phase of minimum 10 minutes at the intended high speed.

xv. First low speed test

Perform the first measurement at the low speed. It shall be ensured that:

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a. the driving speed is constant in a range of 10-15 km/h at least for the measurement section and the preceding stabilization section;

b. the vehicle is driven through the measurement section along a straight line without steering;

c. the amount of recorded measurement sections (of 250 m length each) leads to at least 1 valid dataset for each combination of measurement section and driving direction as driven in the high speed test;

d. the begin and end of the measurement section is clearly recognizable in the measurement data via a recorded trigger signal (opto-electronic barriers plus recorded GPS data) or via use of a DGPS system;

e. During the low speed test the driving at the parts of the proving ground outside the measurement sections and the preceding stabilization sections shall be performed at the highest possible vehicle speed. Any unnecessary manoeuvres shall be avoided during these phases (e.g. driving in sinuous lines, unnecessary accelerations or decelerations).

f. The maximum time for the low speed test shall not exceed 20 minutes in order to prevent cool down of the tires.

xvi. Drive another warm-up phase of minimum 5 minutes at the intended high-speed.

xvii. High speed test

Perform the measurement at the high speed. It shall be ensured that:

a. the driving speed is constant at least for the measurement section and the preceding stabilization section;

b. the vehicle is driven through the measurement section along a straight line without steering;

c. an equal amount of measurement sections is driven in both headings;e.g.: either enough laps on an one-way circuit track with two measurement areas or an equal amount of measurements driven in each direction on a circuit track or straight line track with one measurement area;

d. the amount of recorded measurement sections (of 250 m length each) leads to at least 2 valid datasets for every defined combination of measurement section and driving direction;

e. the begin and end of the measurement sections is clearly recognizable in the measurement data via a recorded trigger signal (opto-electronic barriers plus recorded GPS data) or via use of a DGPS system;

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f. In the driving phases outside the measurement sections and the preceding stabilization sections any unnecessary manoeuvres shall be avoided (e.g. driving in sinuous lines, unnecessary accelerations or decelerations).

xviii. Second low speed test

Perform the second measurement at the low speed directly after the high speed test. Ensure that similar provisions a. to f. than for the first low speed test are fulfilled.

xix. Drift check of torque meters

Directly after the finalisation of the second low speed test the drift check of the torque meters shall be performed:

Bring the vehicle to standstill on the selected standstill area of the test track

Lift the instrumented axle(s) off the ground

Record the signals of all torque meters for a minimum sequence of 30 seconds.

The drift of each torque meter calculated from the average of the minimum sequence of 30 seconds shall be less than < ± 25 Nm.

Exceeding this limit leads to an invalid test.

It is not allowed to change the vehicle load (e.g. by changing the number of occupants) during the sequence starting with xiv and ending with xix.

xx. General checks

Check the axle/wheel bearings for overheating. Measurement shall be done with e.g. a hand-held infrared thermometer at the start of each measurement campaign and after exchanging the test vehicle/trailer.

Re-check the vehicle configuration. Note any differences in height of the box/semi-trailer, etc. in the Testing Logbook.

Fig. 1 gives an overview on the entire test sequence.

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Check of vehicle setup

Preparation of opto-electronic barriers

Installation / Check of torque meters

Check of wheel rotation

Documentation of relevant vehicle data

Determination of vehicle test weight

Check of tyre pressure

Warm-up phase (min. 90 minutes at high speed) optional including

"misalignment test"

Zeroing of torque meter drift

Warm-up phase (min. 10 minutes at high speed)

First low speed test

Warm-up phase (min. 5 minutes at high speed)

Drift check of the torque meters

General checks

Mounting of mobile anemometer

Check of measurement signals / data recording

Engine pre-conditioning (idle)

High speed test

Second low speed test

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Fig. 1: Constant speed test

3.8 Misalignment calibration test

The misalignment of the anemometer shall be determined by a misalignment calibration test on the proving ground. At least 5 valid passings of minimum one of the measurement sections in each direction driven at high vehicle speed are required. The validity criteria for wind conditions as specified in section 3.2 ambient conditions item vi are applicable. The data recorded during the misalignment calibration test are used by the VECTO-CSE tool to calculate the misalignment error and perform the according correction. The signals for wheel torques and engine speed are not used in the evaluation.

The misalignment calibration test can be performed independently from the constant speed test procedure. If the misalignment calibration test is performed separately it shall be executed as follows:

a. Prepare the opto-electronic barriers at the measurement section(s) or the DGPS reference station (whatever is applicable).

b. Check the data registration of all relevant measurement signals (torque meter and engine speed readings as well as vehicle weight are not relevant)

c. Start engine to pre-condition the vehicle (idling without parking brake).d. Check the vehicle setup regarding the height and geometry. Adjust the height of the

semi-trailer to the target value if necessary.e. No prescriptions for warm-up are applicablef. Preform the misalignment calibration test by at least 5 valid passings of minimum one

of the measurement sections in each direction at high vehicle speed. g. Re-check the vehicle configuration. Note any differences in height of the box/semi-

trailer, etc. in the Testing Logbook.

It is required that the anemometer has not been dismounted from the vehicle between the execution of the misalignment calibration test and the constant speed test procedure.

3.9 Testing Logbook

In addition to the recording of the modal measurement data, the testing shall be documented in a logbook which contains at least the following data:

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a. General vehicle description (specifications see Appendix 2 - Information Document)b. Pictures of the tested vehiclec. Actual maximum vehicle height and width and potential deviations during the testingd. km reading (at each step of the testing sequence)e. Start time of the warm-up phase, the high speed test, the low-speed tests and the

misalignment testf. Fuel level and amount of additionally tanked fuel (combined with time and km

reading)g. Number of vehicle occupants (if applicable: time and detail of changes)h. Actual vehicle mass (combined with km reading, occupants and fuel level)i. Time of zeroing the drift of the torque metersj. ID of the first measurement section for each testing sequencek. Driving directionl. Filename of measurement datam. Tarmac temperatures (if applicable according to 3.3.2)n. Documentation of extraordinary events (with time and number of measurement

sections), e.g.

close passing of another vehicle driving errors technical errors measurement errors

o. Engaged gear of the transmission for the low speed test and high speed test

3.10 Data processing

The recorded data shall be synchronised and aligned to 100Hz temporal resolution, either by arithmetical average or linear interpolation.

All recorded data shall be checked for any errors. Measurement data shall be excluded from further consideration in the following cases:

Datasets became invalid due to events during the measurement (see 3.9 item n)

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Instrument saturation during measurement (e.g. high wind gusts which might have led to anemometer signal saturation)

Measurements in which the permitted limits for the torque meter drift were exceeded

For the evaluation of the constant speed tests the application of the VECTO-CSE tool as provided by the European Commission is obligatory. All other evaluation steps including all validity checks (with exception of the list as specified above) are performed by VECTO-CSE.

3.11 VECTO-CSE evaluation algorithms

This section gives a documentation of the evaluation algorithms applied by VECTO-CSE to determine the CdAcr(0) value from the measurement data.

a. Processing of data for vehicle position

In a first step VECTO-CSE converts the (D)GPS coordinates to UTM coordinates. The according results for UTM coordinates can be found in the results files (values: “Lat (UTM)” and “Long (UTM)”). For data inside of measurement sections also the theoretical position of the vehicle projected to the line defined by the start- and end-coordinates of the measurement section (result file values “Lat (root)” and “Long (root)”) is calculated. This coordinate is the reference for the identification of the vehicle position inside the measurement sections.

b. Assignment of measurement data to measurement sections

For assignment of recorded data to the measurement sections two options can be chosen how the point in time is determined when the vehicle enters and exits the predefined measurement sections.

Option 1: Trigger signal

VECTO-CSE identifies the entry or the exit of the vehicle if the criteria 1. to 3. are met:

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1. The trigger signal shows a change in integer value2. The position of the vehicle is inside a control area around the start point or the

end-point a measurement section. The control area is defined by +/- 10 meters (in driving direction) and +/- 100 meters (perpendicular to the driving direction).

3. The heading of the vehicle is within +/- 10° of the target heading.

Option 2: DGPS signal

CSE identifies the entry or the exit of the vehicle if both criteria 1. and 2. are met:

1. An imaginary line perpendicular to a measurement section going through the start point or the end-point is crossed within +/- 100 meters to the start point or to the end-point

2. The heading of the vehicle is within +/- 10° of the target heading.

Important remarks:

If a measurement section is specified in the *.csms file only in a single driving direction, the data recorded on this section during driving in the opposite direction is not evaluated in VECTO-CSE.

If the end point of a measurement section is identical with the start point of the next measurement section the events for “exit” of the first measurement section and “entry” into the next measurement section happen at the same point in time.

c. Calibration of signals for vehicle speed and from anemometry

The signals for:

vehicle speed air speed and yaw angle (beta)

are calibrated in VECTO-CSE as laid down below.

Step 1: Calibration of vehicle speed

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The vehicle speed used in the evaluations is calculated by

vveh=vveh ,CAN∗f v , veh

where:vveh = calibrated vehicle speed [km/h]vveh,CAN = vehicle speed from CAN front axle signal [km/h]fv,veh = calibration factor for vehicle speed [-]and:

f v , veh=vref , avrg

vveh, CAN , avrg

where:vref ,avrg = average reference speed for all valid datasetsvve h ,CAN ,avrg = average CAN vehicle speed for all datasets

The reference vehicle speed is determined depending on the method of assignment of measurement sections as described below:

Option 1: Trigger signal

The reference vehicle speed is calculated by division of the length of the measurement section by the driving time in the measurement section as determined based on the trigger signal.

Option 2: DGPS signal

For the DGPS option the vehicle reference speed is determined by two methods:

by directly using the DGPS vehicle speed by division of the length of the measurement section by the driving time in the

measurement section as determined based on the DGPS coordinates.

Position and velocity are determined by (D)GPS devices by different physical principles. Currently it is not known which of the two methods a) and b) result in higher accuracy. Test data as available during VECTO-CSE development showed only very small deviations of the vehicle speed as determined by methods a) and b). A general selection of

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the method to be used shall be made after the pilot phase. In the current VECTO-CSE version method a) is used for further processing. Calibration factors determined by both methods are shown in the result file.

The vehicle speed calibration is calculated separately for the misalignment test and for the high speed test. The evaluation of the low speed – high speed – low speed sequence is performed based on the calibration factor from the high speed test.

Step 2: Calibration of air speed and yaw angle

For calibration of air speed and yaw angle VECTO-CSE determines the calibration factors “fvpe” (position error of measured air speed) and “βame” (misalignment factor for measured yaw angle). The evaluation steps are done as specified below:

1. In a first evaluation step it is assumed that all datasets have been recorded in valid wind conditions assigning the label “valid=1”.

2. VECTO-CSE checks if a minimum set of five valid datasets per measurement section and driving direction (for the misalignment test) and per headings respectively (for the high speed test) are available. If uneven numbers of datasets for the two driving directions or headings are available, VECTO-CSE discards the last dataset(s) from the driving direction / heading with the higher number of available valid datasets. Invalid datasets are labelled with “used=0”.

3. Based on all “used=1” datasets the calibration factors “fvpe” and “βame” are determined using the formulas as specified below.

f vpe=vveh ,avrg

1/2∗(vair ,ar ,1+vair , ar ,2)❑

where:

fvpe = air speed position error correction factor [-]

vveh, avrg = average vehicle speed during test [m/s]

vair , ic ,1 = average air speed (anemometer reading)

in driving direction 1 [m/s]

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vair , ic , 2 = average air speed (anemometer reading)

in driving direction 2 [m/s]

βame=(βar ,1+βar ,2)

2

where:3

βame = angle misalignment error [°]

βar ,1 = average yaw angle (anemometer reading)

in driving direction 1 [°]

βar , 2 = average yaw angle (anemometer reading)

in driving direction 2 [°]

4. For the yaw angle the correction factor fape (position error) is taken from generic data.Tractor + semi-trailer : f ape=1.0

Rigid truck : f ape=1.0

Citybus : f ape=0.XX (t.b.d)Coach : f ape=0.XX (t.b.d.)

5. With these correction factors the undisturbed air flow for air speed and yaw angle are calculated as specified below:

vUF=vair ,ar∗f vpe

where:

3 Before applying this formula 180° are subtracted from the beta angle as read in from the input file (definition of beta in input file: 180° refers to “headwind conditions)

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vUF = air speed in undisturbed flow conditions [m/s]

f vpe = air speed position error correction factor [-]

vair,ic = air speed signal (anemometer reading) [m/s]

βUF=(β¿¿ar−βame)∗f ape ¿

where: 4

βUF = yaw angle at undisturbed flow conditions [°]

βar = yaw angle signal [°]

βame = angle misalignment error [°]

f ape = angle position error correction factor [-]

6. The boundary layer correction is applied to correct air speed, yaw angle and wind speed as determined for undisturbed flow conditions to average flow conditions as acting on the vehicle.Wind speed (vwind) at undisturbed flow location at height of anemometer (ha):

vwindx (ha )=vUF∗cos ( βUF )−v veh

vwindy (ha )=vUF∗sin ( βUF )

vwind (ha )=¿¿

Wind speed variation with height: Assumption for wind profile using the power law boundary layer and δ=0.2:

4 Before applying this formula 180° are subtracted from the beta angle as read in from the input file (definition of beta in input file: 180° refers to “headwind conditions)

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vwindx (h )=vwindx (ha )∗( hha )

δ

vwindy (h )=vwindy (ha )∗( hha )

δ

Air speed and β variation with height:

vair (h )=¿¿

β (h )=atan ¿

Height-averaged air speed and β

vair=( 1hv )∗∫

0

hv

vair (h ) dh

β=( 1hv )∗∫

0

hv

β (h ) dh

where:

hv = vehicle height [m]

ha = installation height of anemometer above ground [m]

h = height above ground [m]

δ = atmospheric stability coefficient [-]

vwindx = wind speed in x-direction [km/h]

vwindy = wind speed in y-direction [km/h]

vair = air speed [km/h]

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7. Based on the values calculated in 6. the validity of the wind criteria for the single datasets is checked. If the validity of single datasets has been modified, the evaluation process is started again with point 3. If not, the calibration factors “fvpe” and “βame” determined in point 3. are considered final.

The air speed position error correction factor fvpe is calculated both for the misalignment test and for the high speed test separately. The evaluation of the low speed – high speed – low speed sequence is performed based on the calibration factor from the high speed test.

The angle misalignment error factor βame as calculated from the misalignment test is also applied in the evaluation of the low speed – high speed – low speed sequence.

d. Evaluation of the constant speed tests

This section describes the evaluation steps performed for the measurement data recorded in the low speed – high speed –low speed test sequence to determine the the product of drag coefficient by cross sectional area for zero crosswind conditions Cd Acr(0).

Step   1: Calculation of air speed, yaw angle and wind speed VECTO-CSE calculates the values for air speed, yaw angle and wind speed using the formulas as specified in 3.11 item c. This is done in the 100Hz time basis.

Step   2: Calculation of forces from driving resistances VECTO-CSE determines the forces which apply to the vehicle from the driving resistances in the 100Hz time resolution according items i. to iv.:

i. Calculation of total traction force: The total traction force is calculated as specified below:

F trac=(T L+T ¿¿ R)∙

neng∙ π30∙ igear ∙iaxle

vveh¿

where:Ftrac = total traction force [N]TL, TR = corrected torque for left and right wheel [Nm]neng = engine speed [rpm]igear = transmission ratio of engaged gear [-]

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iaxle = axle transmission ratio [-]vveh = vehicle speed [m/s]

ii. Correction for forces from road gradient and accelerations From the total traction force the forces from road gradient and vehicle inertia are subtracted gaining the driving resistance force caused by air drag and rolling resistance:

F res=F trac−Fgrd ∙ sgrd−Facc ∙ sacc

where:Ftrac = driving resistances force (air drag and rolling resistance) [N]Fres = total traction force [N]Fgrd = gradient force [N]sgrd = parameter gradient correction (1=enabled, 0 =disabled) [-]Facc = force from vehicle inertia [N]sacc = parameter acceleration correction (1=enabled, 0=disabled) [-]

The acceleration force is calculated from:

Facc=mveh ∙ aavg+∙I wh ∙ ω̇ ∙ ω

v veh

where:mveh = vehicle mass as specified in *.csveh-file [kg]aavg = vehicle acceleration calculated from the 1s moving averagedvehicle speed signal [m/s²] Iwh = wheels rotational inertia [kgm²]ω̇ = wheels angular acceleration [rad/s²]ω = wheels angular speed [rad/s]vveh = vehicle speed [m/s]

Planned simplification after pilot phase to avoid determination of wheels rotational inertia:

Facc=1.03∗mveh ∙ aavg

The gradient force is calculated from:

Fgrd=mveh ∙ g ∙ sin( ∆ alt∆ dist )

where:mveh = vehicle mass as specified in *.csveh-file [kg]

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g = earth gravitational acceleration (9.81) [m/s²]Δalt = altitude difference from next to previous timestep [m]Δdist = difference of driven distance from next to previous timestep [m]

In VECTO-CSE for the use in the official declaration the gradient correction is disabled. The influence of road gradient does not affect the Cd Acr test result due to the general VECTO-CSE evaluation principle. Hence no altitude profile is required for the measurements. However, the determined values for rolling resistance on single combinations of measurement sections and driving directions are biased by road gradient forces.

iii. Calculation of the air density and vapour pressure The air density is calculated from the air temperature measured on the vehicle and the air temperature, air pressure and relative humidity as measured at the stationary weather station based on the following equations:

pv , H 2O=611 ∙RH stat

100∙ 10

7.5 ∙tamb ,stat

(237+t amb, stat)

ρair=pamb, stat−pv , H 2 O

287.1 ∙(t amb, veh+273.15)+

pv , H 2O

461.9 ∙ (tamb , veh+273.15)

where:pv,H2O = H2O vapour pressure [Pa]RHstat = relative humidity measured by stationary weather station [%]tamb,stat = ambient temperature from stationary weather station [°C]tamb,stat = ambient temperature measured on the vehicle [°C]pamb,stat = ambient pressure from stationary weather station [Pa]

iv. Correction of driving resistance force for the low speed tests The driving resistance forces for the low speed tests are furthermore corrected by the factor froll,corr. :

F res, ref=F res ∙ f roll ,corr

This feature aims for correction of a systematic change of rolling resistance in the low speed tests compared to the high speed tests as driven in the test sequence.

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Example: If the rolling resistance in the low speed tests is known to be at 85% from the rolling resistance in the high speed tests a correction factor of 1/0.85 = 1.176 has to be specified in VECTO-CSE.Default setting for froll,corr in the pilot phase is 1 (i.e. no correction). value t.b.d. for final legislation

Step   3: Check of validity criteria for datasets to be included in the analysis

VECTO-CSE includes single datasets in the test evaluation in case the following validity criteria are met:

valid heading of the vehicle during passing a measurement section (< 10° deviation from target heading applicable for low speed test, high speed test and misalignment test)

valid average wind speed conditions (< 5m/s applicable for low speed test, high speed test and misalignment test)

valid gust wind speed conditions (< 8m/s applicable for low speed test, high speed test and misalignment test)

valid average yaw angle conditions (< 3° applicable for high speed test, < 5° applicable for misalignment test)

stability criteria for vehicle speed met (see 3.2 item “Thresholds for variation of torque and vehicle speed” applicable for low speed test and high speed test)

stability criteria for vehicle torque met (see 3.2 item “Thresholds for variation of torque and vehicle speed” applicable for low speed test and high speed test)

driven distance inside measurement section does not differ from target distance by more than 3 meters (applicable for low speed test and high speed test)

plausibility check for engine speed passed (see formulas below)

High speed test:

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Low speed test:

where:vhms,avrg = average vehicle speed (high speed measurement section)[km/h]neng,1s = 1s moving average of engine speed (high speed measurement

section) [km/h]vlms,avrg = average of vehicle speed per Xms seconds low speed measurement

section [km/h]Xms = time needed to drive 25 meter distance with low speed [s]neng,float = moving average of engine speed with Xms seconds time base (low

speed measurement section) [km/h]rdyn,ref,HS = average effective rolling radius (high speed meas. sections) [m]rdyn,ref,LS = average effective rolling radius (low speed meas. sections) [m]iaxle = axle transmission ratio [-]igear = transmission ratio of the gear selected in high speed or low speed

test [-]

VECTO-CSE excludes single datasets from the evaluation in the following cases:

unequal number of datasets per vehicle heading direction (high speed test)In this case the last dataset(s) from the heading with the higher number of datasets are excluded.

unequal number of datasets for a particular combination of measurement section and driving direction for the first and the second low speed testIn this case the last dataset(s) from the low speed run with the higher number of datasets are excluded.

VECTO-CSE excludes single combinations of measurement sections and driving directions from the evaluation if less than two valid high speed datasets are available.

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VECTO-CSE considers the entire constant speed test invalid in the following cases:

test track requirements not met (max. 20° direction deviations from +/-180° between measurement sections)

less than 10 valid datasets per heading available valid range of ambient conditions (0°C to 25°C) exceeded maximum variation of ambient temperature (3°C) exceeded valid range of proving ground temperature (below 40°C) exceeded maximum deviation of RRC between first and second low speed test (0.3 kg/t)

exceeded

Step   4: Calculation of C dxAcr values for all combination of measurement sections and driving directionsFor all applicable combinations of measurement sections and driving directions the following analysis is performed:

Setup of a linear regression for all used=1 datasets from the high speed tests and the two low speed tests for Fres,ref as a function of squared air speed (vair

2) achieving an constant term F0 (unit [N]) and regression coefficient F2 (unit: [Ns²/m²]). In the regression weighting factors are applied so that the cumulative weighting of all high speed datasets is 50%. The constant term F0 is interpreted as sum of all constant forces (rolling resistance, gradient resistance, side inclination, bearing losses etc.).

The value for Cd∙Acr (β) is calculated for each high speed dataset as follows:

Cd ∙ A cr(β )=2 ∙( F res ,ref−F0 )(vair

2∙ ρair ,ref ) The average value for Cd∙Acr(β) for the particular combination of measurement and

driving direction is calculated from the related values of all used high speed datasets by arithmetical averaging.

The average absolute yaw angle β is calculated from all high speed datasets The rolling resistance coefficient (RRC, unit [kg/t]) is calculated for the first low

speed test (LS1) and for the second low speed test (LS2) from

RRC LS1/LS 2=1000∙ F0 LS1 /LS2

mveh ∙9.81where:F0,LS1 / LS2 = constant term from the regression of Fres,ref as a function of squared

air speed (vair2) using all high speed datasets and the dataset of the

particular low speed test (LS1 or LS2) [N]

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mveh = average vehicle mass during the test [kg]

Step   5: Determination of overall test result The result for overall Cd∙Acr (βavrg) and the according overall average yaw angle βavrg is calculated from the results for all applicable combinations of measurement sections and driving directions by arithmetical averaging.The final result for product of drag coefficient by cross sectional area for zero cross-wind conditions Cd∙Acr(0) is then achieved performing the yaw angle correction as specified below:

Cd ∙ A cr (0 )=Cd ∙ A cr ( βavrg )−∆ Cd ∙ Acr (βavrg)

where:Cd ∙ Acr ( βavrg ) = average result for product of air drag coefficient and frontal area

from constant speed tests comprising the average absolute yaw angle of βavrg

∆ Cd ∙ A cr (βavrg) = yaw angle correction applying the generic curve for ∆ Cd ∙ A fr as a function yaw angle for the value of βavrg. In this correction the applicable generic curve for the particular vehicle class and vehicle configuration (rigid or with trailer) as specified in 3.12 is used.

3.12 Generic data for dependency of CdAcr with yaw angle β

In the evaluations the following dependency of CdAcr with yaw angle shall be used:

∆ Cd ∙ A cr ( β )=a1 ∙ β+a2 ∙ β2+a3 ∙ β3

For the coefficients a1 to a3 the following vehicle class specific values are applicable:

rigid solo rigid + trailer

tractor + semitrailer coach, bus

a1 0.013526 0.017125 0.030042 -0.000794

a2 0.017746 0.072275 0.040817 0.021090

a3 -0.000666 -0.004148 -0.002130 -0.001090

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Table 1: Coefficients for yaw angle dependency

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Appendix 1

MODEL OF EC TYPE-APPROVAL CERTIFICATE OF APPROVED COMPONENTS

[Applicable to step-by-step [and mixed type approval?] approach in the case that the component manufacturer is applying for component approval]

Maximum format: A4 (210 x 297 mm)

EC TYPE-APPROVAL CERTIFICATE

Communication concerning:

– EC type-approval(1)

– extension of EC type-approval(1)

– refusal of EC type-approval(1)

– withdrawal of EC type-approval(1)

approved components with regard to Regulation (EC) No XXXX as implemented by Regulation No … [this Regulation].

Regulation (EC) No XXXXX and Regulation No … [this Regulation] as last amended by ……………..

EC type-approval number:

Reason for extension:

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Stamp administration

SECTION I (to be drafted for each component)

0.1. Make (trade name of manufacturer):

0.2. Type:

0.3. Means of identification of type, if marked on the component

0.3.1. Location of the marking:

0.4. Name and address of manufacturer:

0.5. In the case of components and separate technical units, location and method of affixing of the EC approval mark:

0.6. Name(s) and address(es) of assembly plant(s):

0.7. Name and address of the manufacturer's representative (if any)

SECTION II (to be drafted for each component)

1. Additional information (where applicable): see Addendum

2. Technical service responsible for carrying out the tests:

3. Date of test report:

4. Number of test report:

5. Remarks (if any): see Addendum

6. Place:

7. Date:

8. Signature:

Attachments:

Information package. Test report.

Appendix 2

Vehicle Body and Air Drag Information Document – Draft V1

Description sheet no.: Issue:

from:

Amendment:

pursuant to … of Council directive … relating to EC Type-Approval(of a axle type - if applicable)

Vehicle Body and Air Drag type:

General remark: For VECTO input data an electronic file format need to be defined which can be used for data import to the VECTO. The VECTO input data may differ from the data requested in the information document and vice versa (to be defined). A data file is especially necessary wherever large data such as efficiency maps need to be handled (no manual transfer / input necessary).

…

0.0. GENERAL

0.1. Name and address of manufacturer

0.2. Make (trade name of manufacturer):

0.3. Vehicle Body and Air Drag type:

0.4. Vehicle Body and Air Drag family (if applicable):

0.5.

Vehicle Body and Air Drag type as separate technical unit / Vehicle Body and Air Drag family as separate technical unit

0.6. Commercial name(s) (if available):

0.7.

Means of identification of type, if marked on the vehicle:

0.8.

In the case of components and separate technical units, location and method of affixing of the EC approval mark:

0.9. Name(s) and address(es) of assembly plant(s):

0.10.

Name and address of the manufacturer's representative:

PART 1

ESSENTIAL CHARACTERISTICS OF THE (PARENT) VEHICLE BODY AND AIR DRAG AND THE VEHICLE BODY AND AIR DRAG

TYPES WITHIN A VEHICLE BODY AND AIR DRAG FAMILY

Parent Vehicle configuration

Vehicle configuration(s) of family

1.0.

SPECIFIC AIR DRAG INFORMATION

1.1. VEHICLE

1.2.0. Vehicle class

1.2.1. Vehicle type

1.2.2. Model

1.2.3. Sub model

1.2.4. Axle configuration

1.2.5. Max. gross vehicle weight

1.2.6.

HDV class according to HDV CO2 scheme

1.2.7. Cabin line

1.2.8. Cabin width

1.2.9. Cabin length

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Parent Vehicle configuration

Vehicle configuration(s) of family

1.2.10. Roof height

1.2.11. Wheel base

1.2.12. Frame height

1.2.13.

Aeordynamic accessories or add-ons (e.g. roof spoiler, side extender, side skirts, corner vanes)

1.2.14. Tire dimensions front axle

1.2.15. Tire dimensions driven axles(s)

1.3.

Body specifications (according to norm body definition)

1.4.

(Semi-) Trailer specifications (according to norm (semi-) trailer specification)

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LIST OF ATTACHMENTS

No. Description Date of issue

1 Information on test conditions

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Attachment 1 to Information Document

Information on test conditions (if applicable)

Test track on which tests have been conducted:

Total vehicle weight during measurement:

Ambient conditions:

Product of drag coefficient (Cd) by cross sectional area (Acr) for zero crosswind conditions CdAcr(0):

Product of drag coefficient (Cd) by cross sectional area (Acr) for average crosswind conditions during constant speed test CdAcr(β):

Average yaw angle during constant speed test β [°]:

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