A method for testing the driving performance of a corner module

Abstract

The application relates to the field of vehicle testing, in particular to a kind of angle module driving performance test method.The test method comprises: according to initial rotational speed, determining torque response test working condition, controlling test bench to execute torque response test;According to the rotational speed-torque grid matrix, determine the efficiency Map test working condition, control execution efficiency Map test;According to rated load and rated torque, determine the thermal decay characteristic test working condition, control execution thermal decay characteristic test;According to vertical load, determine the adhesion limit and starting traction force combined test working condition, control execution adhesion limit and starting traction force combined test;According to the set vehicle speed, determine the uniform speed driving stability test working condition, control frame to execute uniform speed driving stability test;Control test bench to execute 0-100km / h acceleration test.The method can test the angle module driving system in full dimension, high precision and high repeatability, accurately reflect the driving performance of the angle module under real vehicle working condition.

Description

Technical Field

[0001] This application relates to the field of vehicle testing, and more specifically, to a method for testing the driving performance of a corner module. Background Technology

[0002] The wheel-side corner module is the core execution unit of the intelligent chassis, integrating functions such as driving, braking, steering, and suspension. It realizes independent power output and motion control for each wheel, becoming an important development form of chassis architecture for new energy vehicles. The driving performance of the corner module directly determines the core indicators such as vehicle power, driving stability, and energy economy. Precise testing of its dynamic response, thermal stability, and extreme traction capacity are key aspects of the corner module's research, development, calibration, and acceptance.

[0003] Existing vehicle drive system testing methods are mostly based on traditional in-wheel motors or the entire vehicle powertrain. These methods suffer from limited testing conditions and incomplete coverage, failing to design specific test scenarios tailored to the integrated and independently controlled characteristics of corner module technology. Consequently, they cannot accurately reflect the true driving performance of corner modules under different speeds, torques, loads, and disturbance conditions. Furthermore, traditional testing methods lack standardized testing conditions, quantifiable evaluation indicators, and unified judgment criteria, resulting in poor repeatability of test results and hindering the support for the design optimization, control strategy calibration, and vehicle powertrain matching of corner module drive systems.

[0004] Furthermore, corner modules face complex operating conditions in real-world vehicle operation, including low-speed, high-torque start-up, high-speed constant-speed driving, continuous high-load operation, and accelerated load transfer. Existing testing methods fail to simulate these conditions across all dimensions, and the appropriate testing equipment cannot accurately reproduce the actual motion and stress conditions at the wheel ends, thus hindering the effective evaluation of the robustness and ultimate performance of the corner module drive system. Therefore, there is an urgent need to develop a standardized drive performance testing method that aligns with the technical characteristics of corner modules and covers all operating conditions, filling the gap in specialized corner module testing technology and providing technical support for the performance verification of core components of intelligent chassis.

[0005] In view of the above, this application is hereby submitted. Summary of the Invention

[0006] The purpose of this application is to provide a method for testing the driving performance of corner modules, so as to achieve standardized driving performance testing that conforms to the technical characteristics of corner modules and covers all operating conditions.

[0007] To achieve the above objectives, this application adopts the following technical solution: This application provides a method for testing the performance of corner module drivers, including: Based on the initial rotational speed, determine the torque response test conditions and control the test bench to perform the torque response test; Based on the speed-torque grid matrix, determine the efficiency Map test conditions and control the test bench to perform the efficiency Map test; Based on the rated load and rated torque, determine the test conditions for thermal decay characteristics and control the test bench to perform thermal decay characteristic tests. Based on the vertical load, determine the joint test conditions for adhesion limit and starting traction force, and control the test bench to perform the joint test of adhesion limit and starting traction force. Based on the set vehicle speed, determine the constant speed driving stability test conditions, and control the test bench to perform the constant speed driving stability test. The test bench was controlled to perform an acceleration test from 0-100 km / h. The step of determining the torque response test condition based on the initial rotational speed includes: Based on three different initial speeds, three sets of step torque command conditions are determined, which are torque response test conditions. The three sets of step torque command conditions are as follows: Condition 1 is an initial speed of 50 rpm, with a step command of 0 Nm to 80% of the rated torque applied; Condition 2 is an initial speed of 500 rpm, with a step command of 0 Nm to 80% of the rated torque applied; Condition 3 is an initial speed of 20 rpm, with a step command of 0 Nm to 50% of the rated torque applied.

[0008] In some technical solutions, the control test bench performs torque response testing, including: Drive the corner module to the initial speed of each step torque command condition and maintain stable operation for more than 3 seconds; control the drive controller to send step torque commands, and control the command rise time to within 1ms; synchronously collect and record the actual torque value, motor speed, and bus current, and record the duration to cover the entire response process; repeat the test 3 times for each condition, and take the average value after removing abnormal data as the test result.

[0009] In some technical solutions, determining the efficiency Map test conditions based on the speed-torque grid matrix includes: The speed-torque grid matrix scanning was adopted, with the speed range set from 0 to the motor peak speed and the single step size of the speed being 500 rpm; the torque range was set from 0 to the motor rated torque and the single step size of the torque being 10% of the rated torque, to obtain the efficiency map test conditions.

[0010] In some technical solutions, the control test bench performs an efficiency Map test, including: According to the speed-torque grid matrix, the driving angle module enters the steady state operation in sequence. The stable operation time of each set of operating conditions exceeds 30 seconds. Data is collected after the temperature fluctuation within adjacent 10 seconds is ≤2℃. Synchronously collect DC bus input power P_in, output shaft mechanical power P_out, and real-time temperature, and calculate the real-time efficiency η at a single operating point based on the formula η=P_out / P_in; After completing 5 sets of continuous operating condition tests, forced cooling is activated to reduce the temperature of the core components of the corner module to 25°C before continuing the test. After completing all operating point tests, an efficiency map distribution is generated.

[0011] In some technical solutions, determining the test conditions for thermal attenuation characteristics based on rated load and rated torque includes: Using the rated load continuous loading mode, with 80% of the rated torque and 1500 rpm as constant test conditions, the entire process of preheating, continuous loading, and cooling recovery was completed to obtain the test conditions for thermal decay characteristics.

[0012] In some technical solutions, the control test bench performs thermal attenuation characteristic testing, including: The starting angle module is preheated for 30 minutes under the constant test conditions to allow the motor windings, power devices, and reducer to reach thermal equilibrium. The constant test conditions were maintained under continuous loading, and the motor winding temperature, real-time output torque, system efficiency, and controller temperature were recorded every 10 minutes. When the output torque drops by more than 5% or the motor winding temperature exceeds 150°C, the loading is immediately terminated and the motor winding temperature, real-time output torque, system efficiency, and controller temperature are recorded at the time of termination. Disconnect the drive power supply, allow the corner module to cool naturally, and record the cooling time required for the system to recover to 95% of its initial performance; Each test was repeated twice, and the average value was taken after removing outliers as the test result.

[0013] In some technical solutions, the determination of the combined test conditions of adhesion limit and starting traction force based on vertical load includes: Based on the vertical load, determine the adhesion limit condition: the vertical load covers the entire range from 500N to 5000N, with progressive loading in 500N increments; each vertical load increment is further reduced by 10N. Increase drive torque at a constant rate of m / s; Based on the vertical load, the starting traction force conditions are determined: simulating three vertical loads: 1000N unloaded, 2500N half-loaded, and 4000N fully loaded. For each vertical load level, the slope resistance corresponding to 20%, 30%, and 40% gradients is simulated. The corner module is stationary with a 5N load. The driving torque increases linearly at a rate of m / s.

[0014] In some technical solutions, determining the constant-speed driving stability test condition based on a set vehicle speed includes: Three set vehicle speeds of 30 km / h, 60 km / h, and 100 km / h were selected. At each set vehicle speed, standard vertical interference excitation and standard lateral interference excitation were applied sequentially. The standard vertical interference excitation had an amplitude of ±5 cm and a duration of 150 ms. The standard lateral interference excitation had an amplitude of ±3 mm and a duration of 150 ms.

[0015] In some technical solutions, the control test bench performs a constant speed driving stability test, including: The equivalent vehicle speed of the test bench is stabilized to the set vehicle speed and maintained for more than 60 seconds. The standard vertical interference excitation and the standard lateral interference excitation are applied sequentially, and the vehicle speed is kept constant during the interference application. After the interference ends, the steering return time, steering residual angle, steady-state deviation after interference reset, speed fluctuation, and torque fluctuation are collected. Each type of interference is tested three times at the same set vehicle speed, and the average value is taken as the result after removing abnormal data.

[0016] Compared with the prior art, the beneficial effects of this application are as follows: The corner module drive performance testing method proposed in this application is based on the construction of a standardized testing environment and unified testing specifications. Leveraging the superior precision control and simulation capabilities of the test bench, it meticulously constructs test scenarios covering multiple dimensions, including dynamic response, energy conversion efficiency, thermal management stability, extreme traction performance, driving smoothness, and acceleration performance. Simultaneously, it establishes clear and quantifiable evaluation standards and universally applicable judgment rules, achieving the testing objective of high precision and high reproducibility for the corner module drive system, realistically and accurately presenting the drive performance of the corner module in actual vehicle operating scenarios. The test results of this application not only provide crucial technical support for the structural improvement of the corner module drive system, the precise tuning of control strategies, and the coordinated matching of vehicle power, but also create a standardized testing process and model for the industry acceptance of corner module drive performance. Detailed Implementation

[0017] The following description provides exemplary embodiments of this application, including various details to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0018] As mentioned in the background section, existing technologies lack solutions for simulating and testing the full-dimensional drive performance of corner modules, thus failing to effectively evaluate the robustness and ultimate performance of corner module drive systems. To address this, this application sets full-dimensional corner module drive performance test conditions and controls the test bench to perform drive performance tests based on these conditions, comprehensively and accurately reflecting the drive performance of corner modules under real-vehicle conditions. The following detailed description, in conjunction with embodiments, further illustrates this application.

[0019] Example 1 This embodiment provides a method for testing the performance of corner module drivers, including the following steps: S110. Based on the initial rotational speed, determine the torque response test conditions and control the test bench to perform the torque response test.

[0020] The step of determining the torque response test condition based on the initial rotational speed includes: Based on three different initial speeds, three sets of step torque command conditions are determined, which are torque response test conditions. The three sets of step torque command conditions are as follows: Condition 1 is an initial speed of 50 rpm, with a step command of 0 Nm to 80% of the rated torque applied; Condition 2 is an initial speed of 500 rpm, with a step command of 0 Nm to 80% of the rated torque applied; Condition 3 is an initial speed of 20 rpm, with a step command of 0 Nm to 50% of the rated torque applied.

[0021] In the torque response test, the corner module is driven to the initial speed of each step torque command condition and kept running stably for more than 3 seconds; the drive controller is controlled to send a step torque command, and the command rise time is controlled within 1ms; the actual torque value, motor speed, and bus current are collected and recorded synchronously, and the recording time covers the entire response process; each condition is tested 3 times, and the average value is taken as the test result after removing abnormal data.

[0022] S120. Based on the speed-torque grid matrix, determine the efficiency Map test conditions and control the test bench to perform the efficiency Map test.

[0023] Optionally, determining the efficiency Map test conditions based on the speed-torque grid matrix includes: A speed-torque grid matrix scan was used, with the speed range set from 0 to the motor's peak speed and a single step size of 500 rpm; the torque range was set from 0 to the motor's rated torque and a single step size of 10% of the rated torque, resulting in the efficiency map test condition. This test condition covers all conventional drive operating points of the corner module.

[0024] In the efficiency Map test, the speed-torque grid matrix is ​​used to enter each working point in sequence. The drive angle module enters steady-state operation. The stable operation time of each working condition exceeds 30 seconds. Data is collected after the temperature fluctuation within adjacent 10 seconds is ≤2℃. Synchronously collect DC bus input power P_in, output shaft mechanical power P_out, and real-time temperature, and calculate the real-time efficiency η at a single operating point based on the formula η=P_out / P_in; After completing 5 sets of continuous operating condition tests, forced cooling is activated to reduce the temperature of the core components of the corner module to 25°C before continuing the test. After completing all operating point tests, an efficiency map distribution is generated.

[0025] The testing process can be carried out using the test bench's speed and torque coordinated control capabilities, and the efficiency map distribution can be generated using data processing software.

[0026] S130. Determine the test conditions for thermal attenuation characteristics based on the rated load and rated torque, and control the test bench to perform the thermal attenuation characteristic test.

[0027] Optionally, determining the test conditions for thermal attenuation characteristics based on rated load and rated torque includes: Using the rated load continuous loading mode, with 80% of the rated torque and 1500 rpm as constant test conditions, the entire process of preheating, continuous loading, and cooling recovery was completed to obtain the test conditions for thermal decay characteristics.

[0028] In the thermal decay characteristic test, the starting angle module is preheated for 30 minutes under the constant test conditions to allow the motor windings, power devices, and reducer to reach thermal equilibrium. The constant test conditions were maintained under continuous loading, and the motor winding temperature, real-time output torque, system efficiency, and controller temperature were recorded every 10 minutes. When the output torque drops by more than 5% or the motor winding temperature exceeds 150°C, the loading is immediately terminated and the motor winding temperature, real-time output torque, system efficiency, and controller temperature are recorded at the time of termination. Disconnect the drive power supply, allow the corner module to cool naturally, and record the cooling time required for the system to recover to 95% of its initial performance; Each test was repeated twice, and the average value was taken after removing outliers as the test result.

[0029] Thermal attenuation characteristic testing can be carried out by relying on the test bench's ability to maintain constant operating conditions.

[0030] S140. Based on the vertical load, determine the joint test conditions for adhesion limit and starting traction force, and control the test bench to perform the joint test of adhesion limit and starting traction force.

[0031] Optionally, the step of determining the combined test condition of adhesion limit and starting traction force based on vertical load includes: Based on the vertical load, determine the adhesion limit condition: the vertical load covers the entire range from 500N to 5000N, with progressive loading in 500N increments; each vertical load increment is further reduced by 10N. Increase drive torque at a constant rate of m / s; Based on the vertical load, the starting traction force conditions are determined: simulating three vertical loads: 1000N unloaded, 2500N half-loaded, and 4000N fully loaded. For each vertical load level, the slope resistance corresponding to 20%, 30%, and 40% gradients is simulated. The corner module is stationary with a 5N load. The driving torque increases linearly at a rate of m / s.

[0032] The combined test conditions of adhesion limit and starting traction force are divided into two sub-items: adhesion limit test and starting traction force test. They are executed sequentially based on the load loading and slope resistance simulation capabilities of the test bench.

[0033] In the combined adhesion limit and starting traction force test, the adhesion limit test involved vertical loads covering the entire range from 500N to 5000N, applied in increments of 500N; each load increment was further increased by 10N. The driving torque is increased at a constant rate of m / s. When the wheel speed suddenly increases by more than 5%, tire slippage is determined, and the maximum output torque T_max is recorded. The adhesion coefficient μ is calculated according to the formula μ=T_max / (F_z×r), where F_z is the real-time vertical load and r is the effective rolling radius of the tire. Each working condition is repeated 3 times, and the average value is taken as the result.

[0034] Starting traction test: Simulates three vertical loads: 1000N unloaded, 2500N half-loaded, and 4000N fully loaded. For each load level, simulates the slope resistance corresponding to 20%, 30%, and 40% gradients. The corner module is stationary with a 5N load. The driving torque increases linearly at a rate of m / s. When the wheel speed exceeds the drum speed by 5%, the maximum non-slip torque T_max is recorded. The maximum starting traction force F is calculated according to the formula F = T_max / r.

[0035] S150. Based on the set vehicle speed, determine the constant speed driving stability test conditions and control the test bench to perform the constant speed driving stability test.

[0036] Optionally, the determining of the uniform driving stability test condition according to the set vehicle speeds comprises: selecting three set vehicle speeds of 30 km / h, 60 km / h and 100 km / h, applying a standard vertical interference excitation and a standard lateral interference excitation sequentially at each set vehicle speed; wherein the standard vertical interference excitation has an amplitude of ±5 cm and a duration of 150 ms; the standard lateral interference excitation has an amplitude of ±3 mm and a duration of 150 ms.

[0037] In the uniform driving stability test, stabilize the equivalent vehicle speed of the test bench to the set vehicle speed, keep it running stably for more than 60 seconds; apply the standard vertical interference excitation and the standard lateral interference excitation sequentially, keep the vehicle speed constant during the interference application; after the interference ends, collect the steering return time, residual steering angle, steady-state deviation after interference reset, rotational speed fluctuation, and torque fluctuation; repeat the test 3 times for each interference at the same set vehicle speed, and take the average value as the result after eliminating abnormal data.

[0038] S160, controlling the test bench to perform 0-100km / h acceleration test.

[0039] The 0-100km / h acceleration test condition comprises: generating dynamic vertical load based on the vehicle dynamics mathematical model, wherein the dynamic vertical load is used to reproduce bearing transfer during acceleration; the 0-100km / h continuous acceleration test is performed by using the dynamic vertical load.

[0040] In the 0-100km / h acceleration test, based on the vehicle dynamics mathematical model, the continuous acceleration process of 0-100km / h is simulated, and relying on the dynamic load loading capability of the test bench, dynamic vertical load is applied synchronously to reproduce the axle load transfer during acceleration; the corner module is tested in two installation states: front axle wheel and rear axle wheel, respectively. Input the key vehicle parameters to generate a dynamic control command file for the sprung loading mechanism of the test bench, so as to realize linkage control of the test bench and the load actuator; preheat the corner module, and keep it running stably at 50% rated torque for 10 minutes; start the full-automatic test program, perform the 0-100km / h continuous acceleration test, and collect parameters such as vehicle speed, driving torque, dynamic vertical load, wheel slip rate, and core component temperature throughout the whole process; monitor the wheel slip state in real time, when the sudden increase of wheel speed relative to vehicle speed is more than 5%, it is determined as slipping and relevant data is recorded; one complete test is completed for each of the front axle and rear axle states.

[0041] Before S110, pre-test preparations are also included: mechanically assembling the corner module onto the wheel-coupled five-degree-of-freedom test bench, completing the debugging of the lubrication and cooling systems to ensure there are no mechanical interference or leakage issues; calibrating all test sensors, such as the high-precision dynamic torque sensor, wheel speed / rotation sensor, and voltage and current acquisition module, and setting the sampling frequency of the CANoe data acquisition system to no less than 1kHz; controlling the test environment temperature to 20±5℃ and maintaining the battery SOC within the optimal operating range of 40%~80%; starting the test bench for pre-running to a thermally stable state to eliminate initial system disturbances and confirm that there are no fault alarms in the corner module and the test bench.

[0042] Following S160, it also includes indicator evaluation, including: (a) After the torque response test, calculate five evaluation indicators based on the test results: torque response time, torque overshoot, torque stabilization time, speed fluctuation value, and current response time. All indicators must meet the following requirements: torque response time ≤ 15ms, torque overshoot ≤ 8%, torque stabilization time ≤ 30ms, speed fluctuation value at 50rpm and 500rpm operating conditions ≤ 2rpm, and current response time ≤ 12ms.

[0043] (b) After the efficiency map test, calculate the three evaluation indicators of the system’s high efficiency zone, peak working efficiency, and rated operating point efficiency based on the efficiency map distribution map. All indicators must meet the following requirements: the proportion of working area with efficiency η > 90% is not less than 35%, peak working efficiency is not less than 95.5%, and rated operating point efficiency is not less than 93%.

[0044] (c) After the thermal decay characteristic test, the evaluation indicators must meet the following requirements: torque decay ≤5% during continuous loading, motor winding temperature ≤150℃, performance recovers to more than 95% of the initial performance within 60 minutes of natural cooling, and temperature fluctuation ≤3℃ / 10min after thermal equilibrium.

[0045] (d) After the adhesion limit, the asphalt pavement adhesion coefficient μ should be ≥ 0.8, and the fluctuation error should be ≤ ±0.05. After the starting traction force test, under a full load of 4000N and a 40% slope, the starting traction force should not be less than 1.2 times the theoretical resistance. Common requirements: The repeatability of both sub-tests should be such that the deviation of the results of three tests under the same working conditions is ≤ 3%, and the vertical load control accuracy should meet ±10N for the adhesion test and ±50N for the starting test.

[0046] (e) After the constant speed driving stability test, all indicators must meet the following requirements: steering return time ≤ 0.5s, steering residual angle ≤ 0.5°, steady state deviation after disturbance reset ≤ 0.2°, constant speed driving speed fluctuation ≤ ±15rpm, constant speed driving torque fluctuation ≤ ±3%, and there should be no deviation, vibration, abnormal noise or fault alarm throughout the test.

[0047] (f) After the 0-100km / h acceleration test, the acceleration time meets the design target and there is no obvious power loss. The wheel slip rate is controlled ≤5% throughout the acceleration process, the steering return torque fluctuation is ≤±5%, the motor and controller do not trigger overheat protection, the dynamic vertical load following error is ≤±3%, and there is no abnormal noise, vibration, or torque interruption throughout the test.

[0048] Next, a comprehensive qualification assessment is conducted: if all the evaluation indicators of the above test items meet the quantitative requirements set in this application, and there are no sensor abnormalities, equipment alarms, corner module failures, etc. during the test, the driving performance of the corner module is deemed qualified; if any evaluation indicator of any test item fails to meet the requirements, or if the above-mentioned abnormalities occur during the test, the driving performance of the corner module is deemed unqualified, and hardware or control strategy problems need to be investigated before the full process test is re-executed.

[0049] The method described in this application can achieve the following: (1) Full coverage of test dimensions: This application designed six core test items, including torque response, efficiency map, thermal decay characteristics, adhesion limit and starting traction combined, constant speed driving stability, and 0-100km / h acceleration. These items cover all dimensions of performance indicators of the corner module drive system, such as dynamic response, energy efficiency, thermal stability, limit traction, driving stability, and acceleration performance. They accurately match the complex working conditions of the corner module in real vehicle operation, and the test results can truly reflect the actual driving performance of the corner module.

[0050] (2) High degree of standardization in testing: This application sets unified test environment conditions, sensor calibration requirements, and data acquisition standards. It designs standardized working parameters and test steps for each test item, clarifies quantitative evaluation indicators and general judgment criteria, effectively solves the problems of poor repeatability and lack of unified standards in traditional test methods, and establishes a standardized paradigm for industry acceptance of corner module drive performance.

[0051] (3) The test conditions closely match the actual vehicle: Based on the simulation capability of the test bench, this application reproduces the dynamic load transfer of the actual vehicle acceleration process in the acceleration test, simulates the actual vehicle starting scenario with different loads and slopes in the adhesion limit and starting traction force test, and applies common interferences of the actual vehicle such as road bumps and cross winds in the constant speed driving stability test, so that the test conditions are highly consistent with the actual use scenario of the corner module, and the test data is more valuable for engineering applications.

[0052] (4) The test results are highly instructive: This application can not only determine the passability of the corner module drive performance by drawing efficiency map distribution diagrams, recording torque decay curves, and analyzing slip ratio changes, but also accurately identify key features such as the system's high-efficiency operating range, thermal decay law, and extreme working boundary. This provides core data support for the structural optimization, control strategy calibration, and vehicle power matching of the corner module drive system, and helps improve the efficiency of corner module R&D.

[0053] (5) Strong test bench adaptability: If this application is based on a wheel coupling five-degree-of-freedom test bench, it can more accurately realize multi-dimensional collaborative control and simulation of wheel end speed, torque, load and interference, and reproduce the real motion state and force situation of the corner module when running on the actual vehicle, meet the high precision and multi-condition requirements of corner module drive performance test, and significantly improve the authenticity and reference of test data.

[0054] Example 2 This embodiment provides a method for testing the performance of corner module drivers, including the following steps: 1. Precise preparation of test benches and supporting equipment A wheel-coupled five-degree-of-freedom test bench with precise control over wheel-end speed, torque, triaxial load, and vertical / lateral disturbances was selected. The bench must meet the requirements of multi-parameter collaborative closed-loop control, with core control accuracy reaching: speed ±1 rpm, torque ±0.1 Nm, vertical load ±10 N, equivalent vehicle speed ±0.5 km / h, and disturbance excitation response time ≤10 ms. High-precision test sensors and high-frequency data acquisition equipment were provided. Specific configuration and calibration requirements are as follows: Dynamic torque sensor: accuracy ±0.1%, sampling frequency 1kHz, 3-point calibration (0Nm, 50% rated torque, rated torque) to be completed before testing; Wheel speed / rotation speed sensor: resolution 0.1 rpm, sampling frequency 1 kHz, no pulse loss; Voltage and current acquisition module: accuracy ±0.5%, sampling frequency 1kHz, compatible with high voltage DC drive systems; Temperature sensor: accuracy ±0.5℃, located in the core positions of motor windings, reducer, and controller; CANoe High-Frequency Data Acquisition System: Version V11 and above, sampling frequency 2kHz, supports multi-channel synchronous data acquisition and real-time storage. All sensors have completed professional calibration and are within their validity period. The test bench is debugged to ensure precise control of each degree of freedom with no linkage error, and the bench self-test pass rate is 100%. The communication baud rate of each system is ≥500kbps, and there is no delay in data interaction.

[0055] 2. Integrated installation of corner modules and full system debugging Mechanical installation: The corner module to be tested is fixed to the wheel end mounting position of the test bench using a customized high-strength aluminum alloy clamp. The clamp is double fixed with positioning pins and bolts to ensure that the coaxiality of the corner module is ≤0.02mm and the perpendicularity is ≤0.01°. Shock-absorbing pads (hardness 50 Shore A) are added to the contact parts between the clamp and the corner module to avoid interference from test vibration. System connection: The corner module is connected to the drive controller, power battery pack, cooling system and lubrication system in sequence. The wiring is arranged with shielded wires and grounded. The cooling pipes are high-pressure explosion-proof pipes. The pipe pressure is adjusted to 0.3MPa±0.02MPa. The lubrication system oil level is at the calibrated scale and there is no leakage. Full system debugging: Single system debugging: Trigger the drive, cooling, and lubrication systems separately to check whether the motor torque output, speed regulation, cooling flow, and lubrication pressure are normal, and whether there is any mechanical jamming, abnormal noise, or leakage; Bench linkage debugging: Start the bench idle program to simulate typical speeds such as 50rpm, 500rpm, and 1500rpm, and confirm that the speed and torque response of the angle module are synchronized in real time, with no fault codes and no packet loss in data acquisition. Protection program test: Trigger overcurrent, overheat, and overtorque protection programs to confirm the linkage between the bench and corner module protection logic, and the test can be terminated and an alarm can be triggered in a timely manner.

[0056] 3. Precise control of standardized testing conditions Environmental conditions: The testing laboratory will be controlled by a constant temperature and humidity air conditioner at a temperature of 23℃±1℃ and a relative humidity of 55%RH±5%RH. Frequent entry and exit of personnel will be avoided during the testing process to reduce environmental fluctuations. Power battery: The SOC of the power battery is precisely adjusted to 60%±2% through charging and discharging equipment. During the test, the bus voltage is kept stable through a regulated power supply with voltage fluctuation ≤±0.1V to avoid voltage fluctuation affecting torque output; Test bench preheating: Start the test bench pre-run program and pre-run at 30% rated torque and 500 rpm for 15 minutes to allow the angle module motor winding, reducer and controller to reach a thermally stable state. The motor winding temperature is stable at 45℃±2℃ and the temperature fluctuation is ≤2℃ / 10min. Data acquisition settings: Set the sampling frequency of the CANoe data acquisition system to 2kHz (higher than 1kHz), complete the calibration and debugging of all acquisition channels, set the data storage path and format, and ensure that multi-channel data is acquired synchronously (synchronization error ≤1ms), without packet loss or garbled characters.

[0057] 4. Refined implementation of six core test items 4.1 Torque Response Test The test bench uses closed-loop control to drive the corner module to initial speeds of 50rpm±1rpm, 500rpm±1rpm, and 20rpm±1rpm respectively, maintaining stable operation for more than 3 seconds with speed fluctuations ≤±1rpm. The drive controller sends a step torque command with a rise time precisely controlled within 0.8ms (better than 1ms), with no delay or overshoot. Simultaneously, the CANoe system collects data such as actual torque, motor speed, and bus current at 1ms intervals, recording the entire process from command issuance to torque stabilization. Each operating condition is repeated three times, with a 3-minute interval between tests to allow the corner module components to return to a stable temperature. Abnormal data with deviations exceeding ±8% are discarded from the three tests, and the arithmetic mean of the valid data is taken as the test result. Five core indicators, including torque response time, overshoot, and settling time, are calculated as required, verifying that all indicators meet the set requirements.

[0058] 4.2 Efficiency Map Test Tests are performed sequentially according to the set speed-torque grid matrix (speed from 0 to peak speed, step size 500 rpm; torque from 0 to rated torque, step size 10% of rated torque). The test bench achieves coordinated closed-loop control of speed and torque, with speed control accuracy ±5 rpm and torque control accuracy ±0.1 Nm. After each set of working conditions is entered, the test bench runs stably for no less than 30 seconds. Data collection begins after the temperature fluctuation of the core components is ≤2℃ within the adjacent 10 seconds. Parameters such as DC bus input power, output shaft mechanical power, and real-time temperature are collected synchronously, with power acquisition accuracy ±0.5%. The real-time efficiency of a single working point is accurately calculated based on the formula η=P_out / P_in. After completing 5 sets of continuous operating condition tests, the bench forced water cooling system is immediately started to reduce the temperature of core components such as the corner module motor windings and reducers to 25℃±2℃ before continuing subsequent tests, so as to avoid heat accumulation affecting test accuracy. After completing all grid point tests, a two-dimensional efficiency map distribution is generated using Matlab / Simulink professional data processing software, marking the efficiency value and high-efficiency zone range of each operating point, and statistically analyzing the percentage of high-efficiency zone, peak working efficiency, and rated operating point efficiency.

[0059] 4.3 Thermal Attenuation Characteristics Test The starting angle module preheats at a constant speed for 30 minutes under the set operating conditions of 80% rated torque ±0.5% and 1500rpm ±5rpm until the motor windings, power devices, and reducer reach thermal equilibrium (temperature fluctuation ≤2℃ for 10 consecutive minutes). Relying on the constant operating condition maintenance capability of the test bench, closed-loop control maintains continuous loading under the set operating conditions. Every 10 minutes, key data such as motor winding temperature, real-time output torque, system efficiency, controller temperature, and cooling system flow rate are recorded. The temperature acquisition accuracy is ±0.5℃, and the torque acquisition accuracy is ±0.1Nm. When the output torque drops by more than 5% or the motor winding temperature exceeds 150°C, the bench protection program is immediately triggered to terminate the loading and record all relevant data at the time of termination. The drive power is cut off, the forced cooling system is turned off, and the corner module is allowed to cool in the laboratory under natural conditions. The torque recovery value and the temperature drop value of the core components are recorded every 5 minutes until the system performance recovers to more than 95% of the initial performance. The required cooling time is recorded. Each test is repeated twice, and the average value is taken after removing abnormal data to verify that the torque attenuation, temperature control, and cooling recovery indicators all meet the requirements.

[0060] 4.4 Joint Test of Adhesion Limit and Starting Traction Force Adhesion limit test: Vertical loads are applied in increments of 500N to 5000N, with a load control accuracy of ±10N. Each load increment is further reduced by 10N. The driving torque is increased uniformly at a constant rate of m / s, with a torque loading accuracy of ±0.1Nm. When a sudden increase in wheel speed exceeding 5% is detected, the tire is immediately determined to be in a slipping state, the torque loading is stopped, and the maximum output torque T_max is recorded. The adhesion coefficient μ is calculated based on the formula μ=T_max / (F_z×r) (r is the effective rolling radius of the tire, with an accuracy of ±0.001m). Each working condition is repeated 3 times, and the average value is taken as the result to verify that the asphalt pavement adhesion coefficient μ≥0.8, and the fluctuation error of the 3 test results under the same working condition is ≤±0.05. Starting traction test: Accurately simulate three vertical loads: no load 1000N, half load 2500N, and full load 4000N, with a load control accuracy of ±50N. Under each load level, the slope resistance corresponding to 20%, 30%, and 40% gradients is simulated, with a resistance simulation accuracy of ±1%. The corner module remains stationary, and a 5N... The driving torque increases linearly at a speed of m / s. When the wheel speed exceeds the drum speed by 5%, the maximum non-slip torque T_max is recorded. The maximum starting traction force is calculated based on the formula F = T_max / r. It is verified that under the conditions of full load of 4000N and 40% slope, the starting traction force is not less than 1.2 times the theoretical resistance, and both sub-tests meet the common requirement that the deviation of the results of 3 tests under the same conditions is ≤3%.

[0061] 4.5 Stability Test During Constant Speed ​​Driving The test bench was set with three equivalent vehicle speeds of 30km / h, 60km / h, and 100km / h in sequence. The closed-loop control accuracy of the vehicle speed was ±0.5km / h. The test bench maintained stable operation for no less than 60 seconds at each speed, and the vehicle speed fluctuation was ≤±0.5km / h. Standard vertical disturbance excitation (amplitude ±5cm, duration 150ms) and standard lateral disturbance excitation (amplitude ±3mm, duration 150ms) were applied sequentially through the test bench actuator. The disturbance loading response time was ≤10ms, and the vehicle speed was kept constant during the disturbance application process. After the interference ended, parameters such as steering return time, steering residual angle, steady-state deviation after interference reset, speed fluctuation, and torque fluctuation were continuously collected within 5 seconds. The angle acquisition accuracy was ±0.01°, the speed acquisition accuracy was ±1 rpm, and the torque acquisition accuracy was ±0.1 Nm. Each type of interference was tested three times at the same vehicle speed, with a 5-minute interval between each test. After removing abnormal data, the average value was taken as the result to verify that all indicators met the set requirements. Throughout the test, the angle module did not exhibit any deviation, vibration, abnormal noise, or fault alarm.

[0062] 4.6 0-100km / h acceleration test Key parameters such as vehicle curb weight, track width, wheelbase, effective rolling radius of tires, and center of gravity height are pre-entered. Dynamic control command files for the test bench's sprung loading mechanism are generated using bench simulation software, achieving synchronous linkage control between the bench drum and the load actuator. Dynamic vertical load following accuracy is ±3%, accurately replicating the axle load transfer characteristics during vehicle acceleration. The diagonal modules are preheated and run stably at 50% rated torque for 10 minutes to bring core components to normal operating temperature. The fully automatic bench test program is then initiated, executing a continuous acceleration test from 0-100km / h. Throughout the test, data is collected at 1ms intervals, simultaneously capturing parameters such as vehicle speed, drive torque, dynamic vertical load, wheel slip rate, and core component temperature. Wheel slip is monitored in real-time; a sudden increase in wheel speed relative to vehicle speed exceeding 5% is considered slip, and the slip time, slip rate, and real-time torque are recorded. The corner module was tested once in each of the two installation states: front axle wheel and rear axle wheel. After the test, the corner module was allowed to cool naturally to room temperature before the installation state was switched. The acceleration time was verified to meet the design target, the slip rate during the acceleration was ≤5%, there was no overheat protection triggering, and there was no abnormal noise / vibration / torque interruption.

[0063] 5. Professional data processing and accurate assessment of overall eligibility Professional data processing software such as Matlab / Simulink and Origin were used to filter, denoise, and synchronize the collected raw data, eliminating outlier data points. The core evaluation indicators for each test item were accurately calculated according to the formulas and requirements in this application's technical solution. Simultaneously, efficiency map distribution diagrams, torque decay curves, acceleration-time curves, and slip ratio change curves were plotted to visually demonstrate the corner module drive performance characteristics. Strictly adhering to the comprehensive pass / fail criteria, all evaluation indicators for the six core test items, including torque response, efficiency map, and thermal decay characteristics, were verified to ensure they met the quantitative requirements set in this application. Furthermore, the test bench fault log and data acquisition log were reviewed to confirm that there were no sensor anomalies, equipment alarms, corner module failures, or data acquisition interruptions during the testing process. If all indicators meet the requirements, a formal corner module drive performance qualification test report will be issued. The report will include complete content such as basic test information, bench and corner module parameters, raw test data, data processing results, calculated values ​​of core indicators, performance characteristic curves, and judgment conclusions. If any indicator fails to meet the requirements, the root cause of the problem will be located through fault tracing analysis. If it is a control strategy problem, the drive controller parameters and control algorithm will be optimized. If it is a hardware structure problem, the corner module motor, reducer, transmission structure, etc. will be rectified. After rectification, a full-process test will be carried out again on the wheel coupling five-degree-of-freedom test bench.

[0064] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this application can be achieved, and this is not limited herein.

[0065] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for testing the performance of a corner module driver, characterized in that, include: Based on the initial rotational speed, determine the torque response test conditions and control the test bench to perform the torque response test; Based on the speed-torque grid matrix, determine the efficiency Map test conditions and control the test bench to perform the efficiency Map test; Based on the rated load and rated torque, determine the test conditions for thermal decay characteristics and control the test bench to perform thermal decay characteristic tests. Based on the vertical load, determine the joint test conditions for adhesion limit and starting traction force, and control the test bench to perform the joint test of adhesion limit and starting traction force. Based on the set vehicle speed, determine the constant speed driving stability test conditions, and control the test bench to perform the constant speed driving stability test. The test bench was controlled to perform an acceleration test from 0-100 km / h. The step of determining the torque response test condition based on the initial rotational speed includes: Based on three different initial speeds, three sets of step torque command conditions are determined, which are torque response test conditions. The three sets of step torque command conditions are as follows: Condition 1 is an initial speed of 50 rpm, with a step command of 0 Nm to 80% of the rated torque applied; Condition 2 is an initial speed of 500 rpm, with a step command of 0 Nm to 80% of the rated torque applied; Condition 3 is an initial speed of 20 rpm, with a step command of 0 Nm to 50% of the rated torque applied.

2. The corner module drive performance testing method according to claim 1, characterized in that, The control test bench performs torque response testing, including: Drive the corner module to the initial speed of each step torque command condition and maintain stable operation for more than 3 seconds; control the drive controller to send step torque commands, and control the command rise time to within 1ms; synchronously collect and record the actual torque value, motor speed, and bus current, and record the duration to cover the entire response process; repeat the test 3 times for each condition, and take the average value after removing abnormal data as the test result.

3. The corner module drive performance testing method according to claim 1, characterized in that, The determination of the efficiency Map test conditions based on the speed-torque grid matrix includes: The speed-torque grid matrix scanning was adopted, with the speed range set from 0 to the motor peak speed and the single step size of the speed being 500 rpm; the torque range was set from 0 to the motor rated torque and the single step size of the torque being 10% of the rated torque, to obtain the efficiency map test conditions.

4. The corner module drive performance testing method according to claim 3, characterized in that, The control test bench execution efficiency Map test includes: According to the speed-torque grid matrix, the driving angle module enters the steady state operation in sequence. The stable operation time of each set of operating conditions exceeds 30 seconds. Data is collected after the temperature fluctuation within adjacent 10 seconds is ≤2℃. Synchronously collect DC bus input power P_in, output shaft mechanical power P_out, and real-time temperature, and calculate the real-time efficiency η at a single operating point based on the formula η=P_out / P_in; After completing 5 sets of continuous operating condition tests, forced cooling is activated to reduce the temperature of the core components of the corner module to 25°C before continuing the test. After completing all operating point tests, an efficiency map distribution is generated.

5. The corner module drive performance testing method according to claim 1, characterized in that, The determination of the thermal attenuation characteristic test conditions based on rated load and rated torque includes: Using the rated load continuous loading mode, with 80% of the rated torque and 1500 rpm as constant test conditions, the entire process of preheating, continuous loading, and cooling recovery was completed to obtain the test conditions for thermal decay characteristics.

6. The corner module drive performance testing method according to claim 5, characterized in that, The control test bench performs thermal decay characteristic tests, including: The starting angle module is preheated for 30 minutes under the constant test conditions to allow the motor windings, power devices, and reducer to reach thermal equilibrium. The constant test conditions were maintained under continuous loading, and the motor winding temperature, real-time output torque, system efficiency, and controller temperature were recorded every 10 minutes. When the output torque drops by more than 5% or the motor winding temperature exceeds 150°C, the loading is immediately terminated and the motor winding temperature, real-time output torque, system efficiency, and controller temperature are recorded at the time of termination. Disconnect the drive power supply, allow the corner module to cool naturally, and record the cooling time required for the system to recover to 95% of its initial performance; Each test was repeated twice, and the average value was taken after removing outliers as the test result.

7. The corner module drive performance testing method according to claim 1, characterized in that, The determination of the combined test conditions for adhesion limit and starting traction force based on vertical load includes: Based on the vertical load, determine the adhesion limit condition: the vertical load covers the entire range from 500N to 5000N, with progressive loading in 500N increments; each vertical load increment is further reduced by 10N. Increase drive torque at a constant rate of m / s; Based on the vertical load, the starting traction force conditions are determined: simulating three vertical loads: 1000N unloaded, 2500N half-loaded, and 4000N fully loaded. For each vertical load level, the slope resistance corresponding to 20%, 30%, and 40% gradients is simulated. The corner module is stationary with a 5N traction force. The driving torque increases linearly at a rate of m / s.

8. The corner module drive performance testing method according to claim 1, characterized in that, The process of determining the constant-speed driving stability test conditions based on a set vehicle speed includes: Three set vehicle speeds of 30 km / h, 60 km / h, and 100 km / h were selected. At each set vehicle speed, standard vertical interference excitation and standard lateral interference excitation were applied sequentially. The standard vertical interference excitation had an amplitude of ±5 cm and a duration of 150 ms. The standard lateral interference excitation had an amplitude of ±3 mm and a duration of 150 ms.

9. The corner module drive performance testing method according to claim 8, characterized in that, The control test bench performs a constant speed driving stability test, including: The equivalent vehicle speed of the test bench is stabilized to the set vehicle speed and maintained for more than 60 seconds. The standard vertical interference excitation and the standard lateral interference excitation are applied sequentially, and the vehicle speed is kept constant during the interference application. After the interference ends, the steering return time, steering residual angle, steady-state deviation after interference reset, speed fluctuation, and torque fluctuation are collected. Each type of interference is tested three times at the same set vehicle speed, and the average value is taken as the result after removing abnormal data.