Bench test method for carrying out load spectrum enhancement test based on WLTC standard working condition

Abstract

The invention discloses a bench test method for carrying out a load spectrum enhancement test based on a WLTC standard working condition, and relates to the technical field of automatic gearbox control, and the method comprises the following steps: 1, inputting parameters needing to be simulated and measured; step 2, carrying out load calculation on the rack; step 3, the rack carries out WLTC working condition test to obtain a working condition signal; step 4, the rack WLTC carries out data processing; and step 5, generating a rack load spectrum. A rack for realizing the method comprises an input motor and an output motor, wherein the output motor comprises a left output motor and a right output motor. The rack is used as a test data source, the rotating speed and torque signals of the input motor and the output motor are high in precision and small in interference influence, the test working condition is the WLTC standard working condition, most people and terrains are covered, rack test data are strengthened, the same rack is used for testing, variables are reduced, the influence of other parts of the whole vehicle on the transmission is avoided, and the test efficiency is improved. And the test period is greatly shortened.

Description

Technical Field

[0001] The present invention belongs to the technical field of automatic transmission control, and in particular, relates to a WLTC standard automatic transmission control system. Bench test method for load spectrum strengthening test under quasi-working conditions. Background Art

[0002] At present, the common load spectrum enhancement test methods mostly use the actual road test of the whole vehicle as the test data source. In the existing technology, firstly, the wheel-end torque meter is difficult to install, and the signal data collected on the whole vehicle is easily affected by the environment. For example, if there is an uneven road surface suddenly, the whole vehicle will be bumpy, the collection equipment will be bumpy, the collected signal will have errors, and the data will be greatly affected by interference; secondly, the engine torque is a calculated value, and there is an error between the data and the actual value; thirdly, the test conditions mainly include mountain, highway, and city, but the proportion of various vehicles driving on different road surfaces is different, and it is impossible to guarantee that enough vehicles are covered when calculating the equivalent life.

[0003] Currently, no technical solution to the above problems has been found. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a bench test method for load spectrum strengthening test based on WLTC standard working conditions, which overcomes the defects of existing control methods. The control method of the present invention uses the bench as the test data source, the equipment has high precision, there is no external force impact, the speed and torque signals of the input motor and the output motor have high precision, and are less affected by interference. The test working conditions are WLTC standard working conditions covering most people and terrains. The bench test data is strengthened and tested on the same bench to reduce variables and avoid the influence of other components of the vehicle on the transmission.

[0005] In order to solve the above technical problems, the technical solution of the present invention is a bench test method for load spectrum strengthening test based on WLTC standard working conditions, comprising the following steps: Step 1: Input the parameters to be simulated and measured; Step 2, the bench performs load calculation; Step 3: Perform WLTC working condition test on the bench to obtain working condition signals; Step 4, the WLTC performs data processing; Step 5: Generate the bench load spectrum.

[0006] Furthermore, in step 1, the whole vehicle is simulated using the test bench drive and load motor. The target torque and target speed of the dynamic mode change in real time. The parameters that need to be simulated and measured need to be input into the test bench host computer software parameters to support real-time calculation.

[0007] Furthermore, in step 2, the control system uses the torque obtained by the left torque sensor and the right torque sensor as the driving force, and the various resistances during vehicle operation as the total resistance, calculates the acceleration at the current moment, and then calculates the vehicle speed, and converts it to the target control speed of the wheels as the target control speed of the output motor.

[0008] Furthermore, the specific steps of obtaining the operating condition signal in step 3 include: Step 1: Edit the WLTC standard operating condition program on the test bench host computer. The WLTC standard operating condition program script contains four different speed ranges, namely low speed, medium speed, high speed and ultra-high speed. The test speed and acceleration of each range are different to simulate different driving environments, and then proceed to step 2; Step 2: Test run: (1) First check whether the communication is normal and whether there are any important fault codes; (2) In manual mode, control the throttle gradually from low to high to check if there is any abnormality. (3) Run the program in automatic mode to verify whether there are any abnormalities in the program; (4) The temperature of the transmission rises to 85±5℃ and the signal status is confirmed; (5) When the test run program and signals are normal, proceed to step 3; Step three: The test bench officially runs the test program.

[0009] Further, in step 4: the test bench WLTC data processing includes the speed and torque of the input motor, and the WLTC test data is classified according to the gear position, and the classifications are: D1 / D2 / D3 / D4 / D5 / D6 / D7 / D8. Each gear position has the corresponding number of rotations of the input shaft of the input motor and the torque test data of the input shaft. According to the basic requirements for the calculation of the rolling bearing life, it is converted into the transmission damage calculation relationship as follows: D=N*T e Where: D-damage value; N - number of rotations of the input shaft; e-ball bearing e=3, roller bearing e=10 / 3; T-input shaft torque, Nm.

[0010] Furthermore, in step 5: the bench WLTC test load spectrum is generated, and the bench host computer processes the data, taking the engine rated speed as the target input speed for each gear, and 110% of the maximum input torque value in the WLTC test as the target input torque for each gear. Among them, the D1 gear takes into account the torque limit requirements of the whole vehicle, and the torque is calculated as 80% of the maximum input torque.

[0011] Furthermore, a test bench for performing load spectrum intensive testing based on WLTC standard working conditions to implement the test method described above includes an input motor and an output motor, the output motor includes a left output motor and a right output motor, and both ends of the input motor are transmission-connected to the left output motor and the right output motor. The left output motor is coaxially arranged with the input motor and the right output motor.

[0012] Furthermore, a left torque sensor is provided between the left output motor and the input motor, a right torque sensor is provided between the right output motor and the input motor, and a torque sensor is provided on the input motor.

[0013] Furthermore, the input motor is a permanent magnet synchronous motor with high dynamic response.

[0014] The present invention adopts the above technical solution, and has the following advantages compared with the prior art: 1. The present invention uses a test bench as a test data source, the equipment has high precision, there is no external force impact, the speed and torque signals of the input motor and the output motor have high precision, and are less affected by interference.

[0015] 2. The test condition of the present invention is the WLTC standard condition. The WLTC standard condition program script contains four different speed intervals, namely low speed, medium speed, high speed and ultra-high speed. The test speed and acceleration of each interval are different to simulate different driving environments and cover most people and terrains.

[0016] 3. The bench test data is strengthened and then tested on the same bench to reduce variables, avoid the impact of other vehicle components on the transmission, avoid the possibility of test failure due to human errors, and improve the efficiency of operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attached Figure 1 It is a frame diagram of the rack structure in an embodiment of the present invention; Attached Figure 2 is a diagram of the parameters of the test bench matching the whole vehicle in an embodiment of the present invention; Attached Figure 3 is a load diagram of a whole vehicle on a test bench in an embodiment of the present invention; Attached Figure 4 is a WLTC working condition test diagram in an embodiment of the present invention; Attached Figure 5 is a bench simulation equivalent time diagram in an embodiment of the present invention; Attached Figure 6 It is a test load spectrum of the bench WLTC test in an embodiment of the present invention.

[0018] In the picture: 1-input motor, 2-left output motor, 3-right output motor, 4-left torque sensor, 5-right torque sensor, 6-torque sensor. DETAILED DESCRIPTION

[0019] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation modes of the present invention are now described with reference to the accompanying drawings. Those skilled in the art should understand that the following does not constitute a limitation on the protection scope of the present invention.

[0020] Examples, such as Figure 1-6 As shown, a bench test method for load spectrum strengthening test based on WLTC standard working conditions includes the following steps: Step 1: Use the test bench drive and load motor to simulate the vehicle. The target torque and target speed of the dynamic mode change in real time. The parameters to be simulated and measured need to be entered in the test bench host computer software parameters to support real-time calculation. The specific parameters are as follows: Figure 2 shown.

[0021] Step 2: When the bench host computer software calculates the bench load, Figure 3 As shown, the various resistances (brake force, friction resistance, slope resistance, air resistance) during vehicle operation are controlled as the total resistance, the acceleration at the current moment is calculated, and then the vehicle speed is calculated and converted to the target control speed of the wheel.

[0022] The bench load calculation has the following characteristics: 1) The core principle is Newton's second law: a=F / m; 2) When going uphill, the slope resistance prevents the vehicle from moving forward; conversely, it promotes the vehicle to move forward; 3) Air resistance changes in real time according to vehicle speed and is proportional to the square of vehicle speed. When vehicle speed increases, air resistance becomes the main factor; 4) The output motor can simulate differential speed conditions according to the turning radius; 5) The braking force is in a linear relationship with the brake pedal by default. For example, if the maximum braking capacity is 5000N and the brake pedal is depressed 50%, the braking force is 2500N.

[0023] Step 3: The bench performs WLTC working condition test. The specific steps for obtaining working condition signals include: Step 1: Edit the WLTC (Worldwide Harmonized Light Vehicles Test Cycle) standard operating program on the test bench host computer. The WLTC standard operating program script contains four different speed ranges, namely low speed, medium speed, high speed and ultra-high speed. The test speed and acceleration of each range are different to simulate different driving environments, and then go to step 2; Step 2: Test run: (1) First check whether the communication is normal and whether there are any important fault codes; (2) In manual mode, gradually increase the throttle to check for any abnormalities. (3) Run the program in automatic mode to verify whether there are any abnormalities in the program; (4) The temperature of the transmission rises to 85±5℃ and the signal status is confirmed; (5) When the test run program and signals are normal, proceed to step 3; Step three: The test bench officially runs the test program, recording the input speed and torque signals, the left and right half-axle output torque signals and speed signals, the vehicle speed signal, the gear position signal, the throttle opening signal, the transmission oil temperature signal, and the brake signal.

[0024] Step 4: The test bench WLTC performs data processing: including inputting the speed and torque of motor 1, such as Figure 5 As shown, the WLTC test data is classified according to the gear position, and the classifications are: D1 / D2 / D3 / D4 / D5 / D6 / D7 / D8. Each gear position has corresponding input motor 1 input shaft rotation number and input shaft torque test data.

[0025] According to the basic requirements for calculating the life of rolling bearings in the national standards GBT 6391-2010 "Rated dynamic load and rated life of rolling bearings" and GBT 24607-2009 "Test and evaluation of the life and reliability of rolling bearings", the transmission damage calculation formula is as follows: D=N*T e Where: D-damage value; N – number of rotations of the input shaft; e-ball bearing e=3, roller bearing e=10 / 3; T-input shaft torque, Nm.

[0026] Specifically, there is only one ball bearing and 11 roller bearings in the transmission structure; the smaller the index is during the calculation process, the greater the calculated damage is.

[0027] Transmission damage is calculated and analyzed according to the roller bearing index 10 / 3.

[0028] By analyzing and calculating the cumulative damage value of each gear required for the entire life cycle of the transmission, and then based on the principle of equal damage.

[0029] The maximum torque, maximum speed and gear information that cause relatively large damage in the actual bench WLTC test are used as the conditions for the enhanced endurance test, and the required equivalent time is calculated.

[0030] The test bench is used as the source of test data. The equipment has high precision and is free of external force impact. The speed and torque signals of the input motor and the output motor are highly accurate and are less affected by interference.

[0031] Step 5: Generate the test load spectrum of the bench WLTC test, such as Figure 6 As shown, the test bench host computer processes the data and takes the rated engine speed as the target input speed for each gear, and 110% of the maximum input torque value in the WLTC test (tested with a safety factor of 1.1) as the target input torque for each gear. Among them, the D1 gear takes into account the torque limit requirements of the whole vehicle, and the torque is calculated as 80% of the maximum input torque.

[0032] A bench for performing load spectrum intensive testing based on WLTC standard working conditions to implement the above test method includes an input motor 1 and an output motor, the output motor includes a left output motor 2 and a right output motor 3, and both ends of the input motor 1 are transmission-connected to the left output motor 2 and the right output motor 3; The left output motor 2 is coaxially arranged with the input motor 1 and the right output motor 3 .

[0033] A left torque sensor 4 is provided between the left output motor 2 and the input motor 1 , a right torque sensor 5 is provided between the right output motor 3 and the input motor 1 , and a torque sensor 6 is provided on the input motor 1 .

[0034] The input motor 1 is a permanent magnet synchronous motor with high dynamic response.

[0035] The bench test conditions are WLTC standard conditions that cover most people and terrains. The bench test data is strengthened and then tested using the same bench test to reduce variables, avoid the impact of other vehicle components on the transmission, and avoid the possibility of test failures due to human errors, while improving the efficiency of working conditions.

[0036] In dynamic mode, the left output motor 2 and the right output motor 3 are responsible for vehicle simulation. The various resistances (brake force, friction resistance, ramp resistance, air resistance) during vehicle operation are controlled as the total resistance, the acceleration at the current moment is calculated, and then the vehicle speed is calculated and converted to the target control speed of the wheels as the target control speed of the left output motor 2 and the right output motor 3. The vehicle transmission control unit TCU communicates with the test bench through CAN.

[0037] For example, at a certain moment, the throttle opening is 50%, the engine speed is 2000rpm, and the initial target torque is 373Nm by looking up the engine Map table (a well-known table, which will not be repeated here). If the automatic transmission control unit receives a torque reduction request of 350Nm at this time, then the target torque is 350Nm, and the test bench control system will control the input motor 1 torque to reach the target value.

[0038] The above is an example of the best implementation of the present invention, and the parts not described in detail are common knowledge of ordinary technicians in the field. The protection scope of the present invention shall be based on the content of the claims, and any equivalent transformation based on the technical enlightenment of the present invention is also within the protection scope of the present invention.

Claims

1. A bench test method for load spectrum strengthening test based on WLTC standard working conditions, Features: The following steps are involved: Step 1: Input the parameters to be simulated and measured; Step 2, the bench performs load calculation; Step 3: Perform WLTC working condition test on the bench to obtain working condition signals; Step 4, the WLTC performs data processing; Step 5: Generate the bench load spectrum.

2. A bench test method for performing load spectrum strengthening test based on WLTC standard working conditions as claimed in claim 1, Features: In step 1, the test bench drive and load motor are used to simulate the whole vehicle. The target torque and target speed of the dynamic mode change in real time. The parameters that need to be simulated and measured need to be entered in the test bench host computer software parameters to support real-time calculation.

3. A bench test method for performing load spectrum strengthening test based on WLTC standard working conditions as claimed in claim 1, Features: In step 2, the control system uses the torque obtained by the left torque sensor (4) and the right torque sensor (5) as the driving force, and uses the various resistances during vehicle operation as the total resistance, calculates the acceleration at the current moment, and then calculates the vehicle speed, and converts it into the target control speed of the wheel as the target control speed of the output motor.

4. A bench test method for performing load spectrum strengthening test based on WLTC standard working conditions as claimed in claim 1, Features: The specific steps of obtaining the working condition signal in step 3 include: Step 1: Edit the WLTC standard operating condition program on the test bench host computer. The WLTC standard operating condition program script contains four different speed ranges, namely low speed, medium speed, high speed and ultra-high speed. The test speed and acceleration of each range are different to simulate different driving environments, and then proceed to step 2; Step 2: Test run: (1) First check whether the communication is normal and whether there are any important fault codes; (2) In manual mode, control the throttle gradually from low to high to check if there is any abnormality. (3) Run the program in automatic mode to verify whether there are any abnormalities in the program; (4) The temperature of the transmission rises to 85±5℃ and the signal status is confirmed; (5) When the test run program and signals are normal, proceed to step 3; Step three: The test bench officially runs the test program.

5. A bench test method for load spectrum strengthening test based on WLTC standard working conditions as claimed in claim 1, Features: In step 4: the test bench WLTC data processing includes the speed and torque of the input motor (1). The WLTC test data is classified according to the gear position, and the classifications are: D1 / D2 / D3 / D4 / D5 / D6 / D7 / D8. Each gear position has the corresponding number of rotations of the input shaft of the input motor (1) and the torque test data of the input shaft. According to the basic requirements for the calculation of the rolling bearing life, it is converted into the transmission damage calculation relationship as follows: D=N*T e Where: D-damage value; N – the number of rotations of the input shaft; e-ball bearing e=3, roller bearing e=10 / 3; T-input shaft torque, Nm.

6. A bench test method for performing load spectrum strengthening test based on WLTC standard working conditions as claimed in claim 1, Features: In step 5: the bench WLTC test load spectrum is generated, and the bench host computer processes the data, taking the engine rated speed as the target input speed for each gear, and 110% of the maximum input torque value in the WLTC test as the target input torque for each gear. Among them, the D1 gear takes into account the torque limit requirements of the whole vehicle, and the torque is calculated as 80% of the maximum input torque.

7. A test bench for performing load spectrum strengthening test based on WLTC standard working conditions according to the test method of claim 1, It is characterized in that It comprises an input motor (1) and an output motor, wherein the output motor comprises a left output motor (2) and a right output motor (3), and two ends of the input motor (1) are transmission-connected to the left output motor (2) and the right output motor (3); The left output motor (2) is coaxially arranged with the input motor (1) and the right output motor (3).

8. A bench for performing load spectrum strengthening test based on WLTC standard working conditions as claimed in claim 7, Features: A left torque sensor (4) is provided between the left output motor (2) and the input motor (1), a right torque sensor (5) is provided between the right output motor (3) and the input motor (1), and a torque sensor (6) is provided on the input motor (1).

9. A bench for performing load spectrum strengthening test based on WLTC standard working conditions as claimed in claim 7, Features: The input motor (1) is a permanent magnet synchronous motor with high dynamic response.

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