Pure electric commercial vehicle gearbox offline test system based on UDS communication

Abstract

The utility model discloses a pure electric commercial vehicle gearbox offline test system based on UDS communication, which comprises a battery and a battery manager, the battery and battery manager inputs direct current into a front-end driving motor MCU through high-voltage power distribution, the front-end driving motor MCU drives a front-end driving motor, and the front-end driving motor is mechanically connected with a gearbox to be tested; the battery and the battery manager input direct current into the rear-end load motor MCU through high-voltage power distribution; the rear-end load motor MCU drives the rear-end load motor, and the rear-end load motor is mechanically connected with the gearbox to be tested; the gearbox to be tested is in low-voltage connection with the gearbox TCU to be tested, and the gearbox TCU to be tested communicates with the industrial personal computer through a UDS network; the industrial personal computer is communicated with the MCU of the front-end driving motor through a CAN (Controller Area Network); and the industrial personal computer communicates with the rear-end load motor MCU through a CAN (Controller Area Network). According to the utility model, the UDS communication is applied to the off-line test of the gearbox, so that the communication of the off-line module is prevented from occupying the CAN network load rate of the whole vehicle and causing interference to the whole vehicle.

Description

Technical Field

[0001] This utility model belongs to the field of pure electric commercial vehicle technology, and relates to gearboxes, specifically to a pure electric commercial vehicle gearbox off-line testing system based on UDS communication. Background Technology

[0002] With the growth of the pure electric commercial vehicle market and the increasing maturity of its technology, reducing the overall vehicle failure rate has become a critical and urgent issue. The overall vehicle failure rate is mainly caused by individual components and their combinations; therefore, reducing the failure rate of individual components is crucial to lowering the overall vehicle failure rate. In the pure electric commercial vehicle sector, the transmission, as a vital powertrain component, primarily controls the vehicle's power transmission, fulfilling requirements such as speed reduction, torque increase, and power take-off. With electrification, transmissions have incorporated electronic control units (ECUs) into their traditional mechanical structures, enabling functions such as automatic shifting, self-learning, precise control of transmission sleeve displacement, and precise control of the solenoid valves in the shift actuators. These functions significantly improve the transmission's shifting performance and transmission efficiency. Furthermore, the application of ECU technology in pure electric transmissions, compared to traditional mechanical transmissions, not only requires higher mechanical reliability but also places higher demands on the stability and reliability of the ECU system and the coordination between the mechanical and ECU components.

[0003] Currently, test benches for pure electric commercial vehicle transmissions can only perform basic tests such as airtightness and static gear shifting. Most lack performance testing such as load-bearing capacity testing and dynamic shifting based on road spectrum, making it impossible to comprehensively assess various test indicators. They also lack remote diagnostic capabilities and data recording, hindering timely and effective fault identification and making it difficult to trace test data and results. Therefore, there is an urgent need to research and develop a comprehensive testing system for pure electric commercial vehicle transmissions. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a pure electric commercial vehicle transmission off-line testing system based on UDS communication, thereby solving the technical problem of difficulty in tracing test data and test results in existing technologies.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A pure electric commercial vehicle transmission off-line testing system based on UDS communication includes a battery and a battery manager. The battery and battery manager input DC power to a front-end drive motor MCU through high-voltage power distribution. The front-end drive motor MCU drives the front-end drive motor, and the front-end drive motor is mechanically connected to the transmission under test.

[0007] The battery and battery manager input DC power to the back-end load motor MCU through high-voltage power distribution; the back-end load motor MCU drives the back-end load motor, and the back-end load motor is mechanically connected to the gearbox under test.

[0008] The gearbox under test is connected to the gearbox TCU at low voltage, and the gearbox TCU communicates with the industrial control computer through the UDS network.

[0009] The industrial control computer communicates with the front-end drive motor MCU via CAN; the industrial control computer also communicates with the back-end load motor MCU via CAN.

[0010] This utility model also has the following technical features:

[0011] The aforementioned front-end drive motor MCU converts high-voltage DC into three-phase AC power (U, V, and W) via an IGBT module to drive the front-end drive motor; the aforementioned rear-end load motor MCU converts high-voltage DC into three-phase AC power (U, V, and W) via an IGBT module to drive the rear-end load motor.

[0012] The front-end drive motor and the gearbox under test are mechanically connected via a splined shaft; the rear-end load motor and the gearbox under test are mechanically connected via a splined shaft.

[0013] The industrial control computer is connected to the front-end drive motor MCU and the back-end load motor MCU via a DB9 serial port connector.

[0014] Compared with the prior art, this utility model has the following technical effects:

[0015] (I) This utility model adopts a novel architecture to achieve off-line testing of transmissions for new energy commercial vehicles. Using an industrial control computer as the core control unit, it controls the front-end drive motor to simulate the driver's operating conditions and controls the rear-end load motor to load according to the actual classic road patterns of the vehicle. The operator can complete the clamping and testing of the transmission assembly with a single click on the industrial control computer. After receiving the instruction, the TCU performs the off-line testing process according to the corresponding procedure. The final test results are saved locally, enabling traceability of off-line data for each transmission. Through the TCU's Tbox function, remote diagnosis of off-line transmission faults is achieved, realizing cloud-based synchronization between R&D and production, and improving the timeliness of fault handling.

[0016] (II) This utility model applies UDS communication to the off-line testing of the transmission, avoiding the communication of the off-line module from occupying the load rate of the vehicle's CAN network and causing interference to the entire vehicle. It realizes that the off-line control module is embedded in the TCU program, with one TCU and one transmission, meeting the TCU's self-learning requirements. Through self-learning, the machining errors of the mechanical sliding sleeves of each transmission and the errors of sensors can be canceled, avoiding control problems caused by errors.

[0017] (III) This utility model enables the platformization of offline testing, meeting the needs of different models of transmissions. Pure electric commercial vehicles include light trucks, medium trucks, heavy trucks, and construction machinery. Depending on the needs of each type of vehicle, the input speed, torque, and power of different transmissions vary greatly. This invention, through the control of the front and rear motors, can simulate the operating conditions of different vehicles. One test bench can meet the offline loading test of different transmission models, greatly saving the offline cost of different transmissions.

[0018] (IV) This utility model enables consistency testing of the solenoid valve enablement in an electro-pneumatic gear shifting actuator. As a crucial component of the gear shifting actuator, the solenoid valve's control precision is often at the millisecond level, and even reaches the microsecond level. Its control accuracy determines the shifting efficiency and quality. During vehicle operation, shifting failures frequently occur due to factors such as gas compressibility and poor solenoid valve enablement consistency. By performing millisecond-level enablement testing on the solenoid valves during the gearbox production process, its reliability can be assessed. This control strategy can effectively screen out faulty solenoid valves, preventing defective parts from entering the market.

[0019] (V) This invention enables the accuracy verification of the input and output shaft speed sensors. The input shaft speed determines the accuracy of the gearbox shifting timing and controls the gearbox input speed to not exceed the upper limit. The output shaft speed is the source of vehicle speed calculation and the source of the motor target speed during shifting. Therefore, the accuracy of the input and output shaft speeds is crucial to the vehicle's operation and shifting. This invention obtains the front-end motor speed of the offline test bench through communication between the UDS and MCU, acquires the input and output shaft speeds through TCU signal acquisition, and performs speed ratio verification to determine that the measurement accuracy of the input and output shaft speed sensors meets the standard (speed < 100 rpm, error less than 5 rpm; speed ≥ 100 rpm, error less than 3%).

[0020] (VI) This invention enables reliability testing of the PTO's engagement and operation. Traditional gearbox assembly requires manual control of the air supply to perform PTO engagement / disengagement tests, which cannot effectively test the reliability of the PTO limit switches. Limit switch failures frequently lead to abnormal PTO engagement / disengagement. The TCU (Transmission Control Unit) enables automatic PTO engagement / disengagement, controlling the air circuit solenoid valve. After the PTO is engaged, the limit switch sends a signal back to the TCU, achieving automatic testing.

[0021] (VI) This invention enables pressure holding tests on shift actuators. Pneumatic shift actuators have high pressure requirements; a pressure greater than 7.5 bar is necessary to guarantee a high success rate for shifting. The pressure holding performance of the actuator cannot be tested by immersion in water. This invention uses an industrial control computer to control the on / off state of the pneumatic solenoid valve and uses UDS communication to provide real-time feedback of the actuator's air pressure value to the TCU. The TCU's internal control strategy can calculate the rate of air pressure decrease per unit time, thereby calculating the precise leakage and completing the pressure holding test of the shift actuator. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of a pure electric commercial vehicle transmission off-line testing system based on UDS communication.

[0023] Figure 2 A schematic diagram of signals transmitted by an industrial control computer.

[0024] Figure 3 This is a schematic diagram of the gear shifting actuator.

[0025] The meanings of the labels in the diagram are as follows: 1-Battery and battery manager, 2-Front-end drive motor MCU, 3-Front-end drive motor, 4-Gearbox under test, 5-Rear-end load motor MCU, 6-Rear-end load motor, 7-Gearbox under test TCU, 8-Industrial computer, 9-Shift actuator.

[0026] 901 - I- and II-axis displacement sensors; 902 - III- and IV-axis displacement sensors; 901 - V- and VI-axis displacement sensors; 904 - I- and II-axis solenoid valves; 905 - III- and IV-axis solenoid valves; 906 - V- and VI-axis solenoid valves.

[0027] The specific content of this utility model will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0028] It should be noted that, unless otherwise specified, all modules, devices and components in this utility model are based on modules, devices and components known in the prior art.

[0029] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0030] Example:

[0031] This embodiment presents a pure electric commercial vehicle transmission off-line testing system based on UDS communication, such as... Figure 1 As shown, it includes a battery and a battery manager 1. The battery and battery manager 1 input DC power to the front drive motor MCU (Microcontroller Unit) 2 through high voltage power distribution. The front drive motor MCU 2 drives the front drive motor 3. The front drive motor 3 is mechanically connected to the gearbox 4 under test.

[0032] like Figure 1 As shown, the battery and battery manager 1 input DC power to the back-end load motor MCU5 through high-voltage power distribution; the back-end load motor MCU5 drives the back-end load motor 6, and the back-end load motor 6 is mechanically connected to the gearbox 4 under test.

[0033] like Figure 1 As shown, the transmission under test 4 is connected to the transmission under test TCU (Telematics Control Unit) 7 via a low-voltage connection. The transmission under test TCU 7 communicates with the industrial control computer 8 through the UDS (Unified Diagnostic Services) network.

[0034] like Figure 1 As shown, the industrial computer 8 communicates with the front-end drive motor MCU2 via CAN (Controller Area Network); the industrial computer 8 also communicates with the back-end load motor MCU5 via CAN.

[0035] As a preferred embodiment, the front-end drive motor MCU2 converts high-voltage DC into three-phase AC power (U, V, and W) via an IGBT (Insulated Gate Bipolar Transistor) module to drive the front-end drive motor 3; the rear-end load motor MCU5 converts high-voltage DC into three-phase AC power (U, V, and W) via an IGBT module to drive the rear-end load motor 6; the IGBT module is an IGBT module known in the art.

[0036] In a preferred embodiment, the front-end drive motor 3 is mechanically connected to the gearbox 4 under test via a splined shaft; the rear-end load motor 6 is also mechanically connected to the gearbox 4 under test via a splined shaft. This splined shaft can be replaced depending on the shaft of the gearbox under test, making it suitable for testing various different gearboxes.

[0037] As a preferred embodiment, the industrial computer 8 is connected to the front-end drive motor MCU2 and the back-end load motor MCU5 via a DB9 serial port connector.

[0038] In this embodiment, the battery and battery manager 1 adopts a battery and battery manager known in the art, and the battery and battery manager 1 provides the entire system with a high voltage of 600V and a low voltage of 24V.

[0039] In this embodiment, the operating interface of the industrial control computer 8 mainly includes a start button, an emergency stop button, and an operation display screen. The operator can perform functional tests of the gearbox through the touch screen. In addition, the touch screen of the industrial control computer 8 can also control the front-end drive motor individually. When clamping and testing the gearbox, a low-speed command (10-30 rpm) is sent to the motor to control the front-end drive motor to rotate at a low speed, which facilitates the automatic mating connection between the spline shaft and the internal spline.

[0040] In this embodiment, the CAN network uses the J16949 CAN communication protocol for signal interaction.

[0041] In this embodiment, as Figure 2 As shown, the solenoid valves of the gearbox under test 4 are installed above the known shift actuator 9. Solenoid valves 904, 905, and 906 on the shift actuator correspond one-to-one with displacement sensors 901, 902, and 903. The solenoid valves are responsible for engaging and disengaging gears. The displacement sensors monitor the displacement of the sliding sleeve and feed back the displacement value to the gearbox TCU7 under test to determine the actual gear position. The gearbox TCU7 under test controls the corresponding solenoid valve on the gearbox shift actuator to enable the target gear position according to the industrial control computer. Pneumatic pressure pushes the shift fork shaft, carrying the sliding sleeve, to complete the engagement and disengagement of gears. The displacement sensors send the actual gear displacement to the gearbox TCU7 under test. The gearbox TCU7 determines whether the actual gear position matches the target gear position and sends the actual displacement corresponding to the gear position to the industrial control computer via UDS communication to generate a test report.

[0042] In this embodiment, the TCU7 of the transmission under test incorporates a known solenoid valve enable control circuit. The solenoid valve is enabled via a PWM signal or high / low side signal. The solenoid valve switch controls the opening or closing of the air circuit on the transmission shift actuator 9, using air pressure to push the slider to complete the transmission's shifting and disengaging actions. To ensure that the shifting conditions are consistent with actual vehicle operation, the industrial control computer monitors the air pressure signal of the offline system in real time via a pressure sensor during testing, ensuring the air pressure value is between 7.5 and 9 Bar. If the air pressure value exceeds this range, the operator will be prompted to check the airtightness of the offline test bench and the air compressor settings.

[0043] In this embodiment, as Figure 2 As shown, displacement sensors are located at the front end and both sides of the shift actuator 9, respectively. They are mechanically connected to the shift fork, feeding back the horizontal displacement value of the shift fork as a voltage signal to the TCU7 of the transmission under test. The TCU7 controller of the transmission under test calculates the current gear of the transmission based on the displacement values ​​of the three axes, verifies it with the target gear, and determines whether the gear engagement is successful.

[0044] In this embodiment, during the off-line testing process, the industrial control computer 8 sends the target torque to the back-end load motor 6 according to the gearbox type, and controls the back-end load motor 6 to perform tests according to the corresponding road spectrum. During the test, the acceleration, deceleration, and gear shifting conditions during actual vehicle operation are simulated. This ensures that the gearbox off-line testing is consistent with actual operating conditions.

[0045] In this embodiment, the TCU7 of the transmission under test controls the gear shifting of the transmission under test 4 and collects sensor signals on the TCU7, sending relevant solenoid valve control signals. The TCU7 of the transmission under test interacts with the industrial control computer 8 to obtain signals of gear position and speed during the gear shifting process of the transmission under test 4, realizing the offline test of the transmission simulating real working conditions. The industrial control computer 8 sends the target torque, speed, and operating mode signals of vehicle drive and load road spectrum to the front-end drive motor MCU2 and the back-end load motor MCU5.

[0046] In this embodiment, specifically, the signals transmitted by the industrial control computer 8 are as follows: Figure 3 As shown in the diagram. The dashed box represents the signal interaction between the industrial computer 8 and the motor, mainly for receiving motor status and sending motor operation commands. The solid box represents the signal interaction between the industrial computer 8 and the TCU7 of the gearbox under test. The industrial computer 8 receives the status feedback from the TCU7 of the gearbox under test, executes the corresponding target commands, and displays relevant information on the screen. The TCU7 of the gearbox under test receives commands from the industrial computer to perform offline testing.

[0047] During the test, the display screen of the industrial control computer 8 displays data synchronously in real time via the CAN line. The operator can observe the status of the gearbox through the real-time data. The industrial control computer 8 will also monitor whether the gearbox is functioning normally by judging the motor speed, gearbox output shaft speed, gearbox displacement value, and gearbox gear position signal.

[0048] During testing, the TCU7 of the gearbox under test enters the gearbox testing function via a request signal from the industrial control computer 8, sequentially performing tests such as pressure holding test, solenoid valve consistency test, gearbox gear self-learning, gearbox speed ratio verification, and dynamic load shifting test. Real-time monitoring is performed according to standards during the testing process. If any test item fails, the testing process is stopped, and the result is fed back to the industrial control computer 8. The industrial control computer 8 displays the fault diagnosis results and troubleshooting measures, and simultaneously controls the front-end drive motor 3 and the rear-end load motor 6 to stop working, restoring the offline test bench to its initial state. After all tests are successful, the success result is displayed on the industrial control computer 8.

[0049] The specific test items and functions of the pure electric commercial vehicle transmission off-line testing system based on UDS communication of this utility model are as follows:

[0050] First, pressure holding test:

[0051] The electro-pneumatic shift actuator 9 has high requirements for air pressure, and its airtightness is crucial. The operator sends a pressure holding test start signal via the industrial control computer 8's panel. The TCU7 of the transmission under test opens the solenoid valves in the air circuit via an enable signal, and also opens the six shift solenoid valves on the shift actuator 9, connecting an air source of 8 bar or higher to the cylinders of the shift actuator 9. Simultaneously, the air pressure sensor feeds back the air pressure value to the TCU7 of the transmission under test in real time via UDS communication. Once the TCU7 detects that the air pressure value has stabilized, it closes the solenoid valves in the air circuit via an enable signal. The TCU7 monitors the air pressure value changes within a set time. If the air pressure drop rate exceeds the target within the set time, the pressure holding test fails. If the air pressure drop rate is within the target value, the shift solenoid valves on the shift actuator 9 close, and a notification of successful pressure holding test is sent to the industrial control computer 8.

[0052] Second, solenoid valve consistency testing:

[0053] The operator sends a solenoid valve consistency test start signal via the panel of the industrial control computer 8. The TCU7 of the gearbox under test determines that the test conditions are met (output shaft speed < 10 rpm, no system faults, air source pressure > 7.5 bar). The first and second solenoid valves on the first shaft of the gearbox are simultaneously enabled, with the activation time difference between the two solenoid valves not exceeding 1 ms. After simultaneous activation, the actual displacement of the gearbox sliding sleeve is obtained through a displacement sensor. At this time, the displacement value should be within the range of 0 ± 0.5 mm. After a set time, the first and second solenoid valves on the first shaft are simultaneously deactivated. At this time, the displacement value should remain in the neutral position at 0 ± 0.5 mm. If the sliding sleeve displacement value shifts to one side, it means that the solenoid valves are inconsistent in deactivation. The same method is used to test the second and third shafts of the gearbox, repeating the cycle three times. If inconsistent deactivation of the solenoid valves occurs, the solenoid valve is determined to be faulty. By enabling each shaft separately, the faulty solenoid valve can be identified, the fault point can be pinpointed, and the testing efficiency can be improved.

[0054] Third, self-learning:

[0055] Self-learning can compensate for machining errors and angular displacement sensor measurement errors in each test gearbox 4, greatly improving the reliability of the gearbox. After receiving the self-learning command, the test gearbox TCU7 first controls the test gearbox 4 to return to neutral. During the self-learning process, the motor works in conjunction to prevent gear misalignment in the test gearbox 4. The test gearbox TCU7 controls the test gearbox 4 to sequentially shift from the lowest gear to the highest gear, learning the displacement values ​​during the shifting process. This learning process is repeated multiple times, and the displacement value corresponding to each gear is written to the controller for storage, serving as a parameter for later gear selection.

[0056] Fourth, speed ratio verification test:

[0057] The TCU7 of the gearbox under test controls the gearbox 4 to shift sequentially from the lowest gear to the highest gear, and controls the speed of the front-end drive motor 3 at each gear. At different speeds, the ratio between the input shaft speed and the output shaft speed of the gearbox 4 under test is verified to ensure it matches the speed ratio of the current gear. The input shaft speed sensor is verified by aligning it with the motor speed, and the output shaft speed sensor is verified by comparing the input shaft speed or the motor speed with the output shaft speed in the current gear ratio. All speed values ​​used in this process are filtered values.

[0058] Fifth, dynamic load shifting test:

[0059] Load spectrum data for each model of the transmission under test 4 is imported into the industrial control computer 8, and the back-end load motor 6 simulates real working conditions. Under the command of the VCU (Vehicle Control Unit), the front-end drive motor 3 begins dynamic upshifting and downshifting tests, simulating the driver's throttle and brake signals to control the output speed and torque of the front-end motor, completing the shift when the appropriate upshifting or downshifting point is reached. This test comprehensively assesses the shifting quality of the transmission under test 4, as well as the reliability of the controller, solenoid valves, angular displacement sensors, and speed sensors.

[0060] In addition, the system is equipped with NVH (Noise, Vibration, and Harshness) sensors, which can accurately record the noise level in decibels during gear shifting. The test bench is also equipped with acceleration sensors in the X, Y, and Z directions, which can accurately reflect the vibration spectrum of the test bench during gear shifting. By accurately identifying the shift noise and vibration spectrum of each gearbox during shifting, it is determined whether the shift smoothness standard is met.

[0061] This pure electric commercial vehicle transmission off-line testing system, through the joint control of an industrial control computer, VCU, TCU, and MCU, achieves one-click operation for the platform-based off-line testing of new energy transmissions. It simulates classic operating routes and conditions of actual vehicles, ensuring that the off-line transmissions meet the actual operational needs of the vehicle, improving the reliability of transmission off-line testing and reducing testing labor costs. After assembling the transmission, staff only need to scan a code to input information such as transmission type and sensor type, and select "start test" with one click. The industrial control computer automatically coordinates the functions of each unit, automatically performs tests according to the test program in the controller, progressively completes the testing of each module's functions, generates an electronic test report, records key parameters during the testing process, and achieves traceability of transmission off-line data. If a module malfunctions during testing, the system can automatically pause the test, pinpoint the cause of the fault, and display a prompt on the industrial control computer interface, helping operators quickly identify the problem and troubleshoot.

Claims

1. A pure electric commercial vehicle gearbox off-line test system based on UDS communication, comprising a battery and a battery manager (1), characterized in that, The battery and battery manager (1) input DC power to the front-end drive motor MCU (2) through high-voltage power distribution, the front-end drive motor MCU (2) drives the front-end drive motor (3), the front-end drive motor (3) is mechanically connected with the transmission to be tested (4); The battery and battery manager (1) input DC power to the back-end load motor MCU (5) through high-voltage power distribution; the back-end load motor MCU (5) drives the back-end load motor (6), the back-end load motor (6) is mechanically connected with the transmission to be tested (4); The transmission to be tested (4) is low-voltage connected with the transmission TCU (7) to be tested, the transmission TCU (7) to be tested is communicated with the industrial computer (8) through the UDS network; The industrial computer (8) is communicated with the front-end drive motor MCU (2) through CAN; the industrial computer (8) is communicated with the back-end load motor MCU (5) through CAN.

2. The UDS communication based off-line testing system for a transmission of a pure electric commercial vehicle according to claim 1, wherein, The front-end drive motor MCU (2) converts high-voltage DC into U, V and W three-phase AC through IGBT module to drive the front-end drive motor (3); the back-end load motor MCU (5) converts high-voltage DC into U, V and W three-phase AC through IGBT module to drive the back-end load motor (6).

3. The UDS communication based off-line testing system for a transmission of a pure electric commercial vehicle of claim 1, wherein, The front-end drive motor (3) is mechanically connected with the transmission to be tested (4) through the spline shaft; the back-end load motor (6) is mechanically connected with the transmission to be tested (4) through the spline shaft.

4. The UDS communication based off-line testing system for a transmission of a pure electric commercial vehicle of claim 1, wherein, The industrial computer (8) is connected with the front-end drive motor MCU (2) and the back-end load motor MCU (5) through DB9 pin serial connector respectively.

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