T/CSAE 78-2018Evaluation and test methods for regenerative braking comfort of electric vehicles (English PDF)

Foreword

This standard is based on GB/T 1.1-2009 "Standardization Work Guide Part 1. Standard Structure and Compilation" Read on.

1 Scope

This standard specifies the evaluation and test methods for the regenerative braking comfort of electric vehicles.

This standard applies to Class M and Class N electric vehicles equipped with a coordinated regenerative braking system.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only the dated version applies to this file. For dated documents, the latest edition (including all amendments) applies to this document.

GB/T 18384.1 Electric Vehicle Safety Requirements Part 1. Vehicle Rechargeable Energy Storage System (REESS) GB/T 19596 electric vehicle terminology GB 21670 Passenger car brake system technical requirements and test methods GB 12676 Technical requirements and test methods for brake systems for commercial vehicles and trailers GB/T 4970 Automotive ride test method

3 Terms and definitions

The definitions of GB/T 18384.1-2015 and GB/T 19596-2017, as well as the following terms and definitions, apply to this document. For the sake of for use, some of the terms and definitions in GB/T 18384.1-2015 and GB/T 19596-2017 are repeated below.

4 Test conditions

5 Test equipment

The test equipment should include an accelerometer, a data acquisition instrument, a vehicle speedometer, a filter, and the like. Test system consisting of test instruments it should be suitable for smoothness measurement, and its performance should be stable and reliable. [GB/T 4970-2009 4.1]

6 Test methods

6.1 Acceleration sensor installation location.

1) Class M vehicles. the driver and the upper seat cushion on the same side, on the seat back, on the floor of the foot;

2) Class N vehicles. above the driver's seat cushion, seat back, and foot floor.

Accelerometers only need to measure longitudinal (X-axis) vibration. For the arrangement of the sensors on the seat back, see GB/T 4970-2009

Figure 2; The sensor on the floor of the step is placed in the middle of the driver's (or occupant) feet. Mounted above the seat cushion, seated

The sensor on the back should be in close contact with the human body. The sensor structure above the seat cushion can be seen in GB/T 4970-2009. Figure B.1.

For the structure of the sensor, see Figure B.2 of GB/T 4970-2009. [GB/T 4970-2009 5.1]

6.2 Adjust the state of charge of the rechargeable energy storage system to near the middle value.

6.3 Test according to the following braking strength.

1) The braking strength is 0.05g;

2) The braking strength is 0.1g;

3) The braking strength is 0.15g;

4) The braking strength is 0.2g;

5) The braking strength is 0.3g.

6.4 Accelerate the vehicle to 120km/h. If the maximum vehicle speed is less than 120km/h, it will run at the highest speed that can be achieved.

6.5 Release the accelerator pedal and wait until the vehicle speed drops to 10km/h below the test speed (ie 110km/h or (maximum speed)-10km/h)), depress the brake pedal and brake at the braking intensity specified in 6.3 until the vehicle stops, recording the test positions Acceleration time history.

3T/CSAE 78 -.2018

6.6 The effective number of tests for each braking strength shall be not less than 5 times.

6.7 For vehicles with multiple coasting regenerative braking strength modes, the corresponding mode should be set before the test and the regenerative braking strength should be set.

The mode is recorded in the test report and the regenerative braking strength mode is not allowed to be changed during the test.

7 Regenerative brake ride comfort evaluation

Regenerative braking ride comfort is evaluated using the vibration dose value (see Appendix A).

8 Data acquisition and processing

Anti-aliasing filters should be used in the data acquisition process. The sampling time interval and frequency resolution involved in data processing should be full.

The foot sampling theorem is determined based on the actual anti-aliasing filter performance indicators and actual engineering needs.

The following parameters are recommended for data collection and data processing.

1) Cutoff frequency. ;

2) Frequency resolution. ;

3) The sampling time interval is based on the anti-aliasing filter performance index used in the data acquisition process on the basis of satisfying the cutoff frequency.

determine. [GB/T 4970-2009 7] 4T/CSAE 78 -.2018 Appendix A (normative appendix) Calculation of Rectification Evaluation Index the regenerative braking smoothness is evaluated by the vibration dose value, and the vibration dose value VDV (unit m/s 1.75) is calculated by the following formula [GB/T 4970-2009 Appendix A A.1.2].

In the formula.

- weighted acceleration time history, in meters per square second (m/s2);

-- The action time (from the time the brake pedal is depressed to the vehicle stop time), in seconds (s).

Wherein, the weighted acceleration time history is weighted by the acceleration time history by the frequency specified in Table A.1 and Table A.2.

Filter network is obtained.

Table A.1 Weighting factors for the octave bands of different longitudinal measurement points

Position frequency weighting function wj Wd above the seat cushion Backrest wc Foot wk

Table A.2 Main weighting factors for the 1/3 octave band

Frequency band number x frequency f/Hz Wk wd wc Frequency weighting Number × 1000 dB Frequency weighting Number × 1000 dB Frequency weighting Number × 1000 dB 1 0.5 418 -7.57 853 -1.38 843 -1.48 2 0.63 459 -6.77 944 -0.50 929 -0.64 3 0.8 477 -6.43 992 -0.07 972 -0.24 4 1 482 -6.33 1011 0.1 991 -0.08 5 1.25 484 -6.29 1008 0.07 1000 0.00 6 1.6 494 -6.12 968 -0.28 1007 0.06 7 2 531 -5.49 890 -1.01 1012 0.10 8 2.5 631 -4.01 776 -2.20 1017 0.15 9 3.15 804 -1.90 642 -3.85 1022 0.19 10 4 967 -0.29 512 -5.82 1024 0.20 11 5 1039 0.33 409 -7.76 1013 0.11 5T/CSAE 78 -.2018 Continued Frequency band number x frequency f/Hz Wk wd wc Frequency weighting Number × 1000 dB Frequency weighting Number × 1000 dB Frequency weighting Number × 1000 dB 12 6.3 1054 0.46 323 -9.81 974 -0.23 13 8 1036 0.31 253 -11.93 891 -1.00 14 10 988 -0.1 212 -13.91 776 -2.20 15 12.5 902 -0.89 161 -15.87 647 -3.79 16 16 768 -2.28 125 -18.03 512 -5.82 17 20 636 -3.93 100 -19.99 409 -7.77 18 25 513 -5.80 80.0 -21.94 325 -9.76 19 31.5 405 -7.86 63.2 -23.98 256 -11.84 20 40 314 -10.05 49.4 -26.13.199 -14.02 21 50 246 -12.19 38.8 -28.22 156 -16.13 22 63 186 -14.61 29.5 -30.60 118 -18.53 23 80 132 -17.56 21.1 -33.53 84.4 -21.47