Reliability test method, device and system for dynamic parking of electric drive axle

Abstract

The invention relates to the technical field of electric vehicle testing, and discloses a reliability test method, device and system for dynamic parking of an electric drive axle, and the method comprises the steps: reading the whole vehicle data of a test vehicle under a pre-defined dynamic parking test condition; according to the test conditions of the whole vehicle data under each dynamic parking test working condition, executing the dynamic parking performance test and durability test of the electric drive axle of the real vehicle at different vehicle speeds, and recording the rotating speed data of the driving motor and the rotating speed data of the rotating speed sensor along with the time change in the test process; and acquiring rotating speed values of the driving motor and the rotating speed sensor when the vehicle is completely driven into the parking gear, calculating the wheel end vehicle speed of the electric drive axle, and judging whether the dynamic parking performance test result is qualified or not and whether the dynamic parking durability test result meets the dynamic parking reliability requirement or not. According to the scheme, the performance and durability of the parking system can be subjected to bench test verification in the early product research and development process, so that the product development period is shortened, and the product quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle testing, and particularly to a reliability test method, device and system for dynamic parking of an electric drive axle. Background Art

[0002] The parking mechanism of an electric drive axle is an important part of the vehicle braking system of new energy vehicles. The performance and durability of the parking mechanism directly affect the safety performance of the whole vehicle. The parking mechanism of the electric drive axle mainly realizes mechanical parking by engaging the parking pawl into the tooth groove of the parking ratchet. According to the national standard requirements, the dynamic parking function should be realized when the vehicle speed is less than 6 km / h during low-speed operation. In order to ensure the reliable operation of the parking mechanism, it is necessary to conduct dynamic parking performance and durability tests on the parking mechanism.

[0003] At present, the existing dynamic performance and durability tests of the parking mechanism are carried out by loading the vehicle on a road test. The test results of the parking mechanism are determined based on the test results of the whole vehicle. This test method has low efficiency, high cost and long cycle. At the same time, the parking test includes misoperation tests, which pose safety risks to the whole vehicle parking test during the development process. Summary of the Invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a reliability test method, device and system for dynamic parking of an electric drive axle, which makes up for the problems of low efficiency, high cost and long cycle in the dynamic parking performance and durability tests of the electric drive axle parking mechanism in the prior art, and there are safety risks.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] In a first aspect, the present application provides a reliability test method for dynamic parking of an electric drive axle, the method comprising:

[0007] Reading the vehicle data of the test vehicle under the predefined dynamic parking test conditions;

[0008] According to the test conditions of each dynamic parking test condition of the vehicle data, performing the dynamic parking performance test and durability test of the electric drive axle of the vehicle at different vehicle speeds, and recording the rotational speed data of the drive motor and the rotational speed sensor changing with time during the test;

[0009] Obtaining the rotational speed values of the drive motor and the rotational speed sensor when the vehicle completely enters the parking gear from the rotational speed data, calculating the wheel-end vehicle speed of the electric drive axle, and judging whether the result of the dynamic parking performance test is qualified based on the wheel-end vehicle speed of the electric drive axle, and whether the result of the dynamic parking durability test meets the dynamic parking reliability requirements.

[0010] Optionally, the predefined dynamic parking test conditions include: analyzing the historical dynamic parking data of the test vehicle under different conditions, obtaining the vehicle data of dynamic parking, calculating the wheel-end inertia in combination with the vehicle model parameters, and formulating dynamic parking test conditions, including: forward parking vehicle speed, reverse parking vehicle speed, and wheel-end inertia.

[0011] Optionally, before performing the dynamic parking performance test and durability test of the electric drive axle of the vehicle at different vehicle speeds according to the test conditions of each dynamic parking test condition of the vehicle data, it further includes: connecting the high-voltage and low-voltage wiring harnesses of the drive motor, motor controller, parking controller, and parking actuator low-voltage wiring harness on the electric drive axle, and installing the electric drive axle to be tested on the test platform through the test fixture;

[0012] One output end of the electric drive axle is free, and the other output end is connected to the rotational speed sensor through a drive shaft. At the same time, the rotational speed sensor

[0013] is connected to the controller host computer through its own data transmission line for rotational speed signal transmission and feedback, and the other end is connected to the inertia device simulating the vehicle inertia through a drive shaft.

[0014] Optionally, performing the dynamic parking performance test of the electric drive axle of the vehicle at different vehicle speeds includes:

[0015] When the test condition includes the forward parking vehicle speed, set the motor controller in the controller host computer software to define the drive motor of the electric drive axle to rotate forward, and perform the dynamic parking performance test of the electric drive axle; and, according to the forward parking vehicle speed extracted from the vehicle data, perform the dynamic parking performance test at each vehicle speed;

[0016] When the test condition includes the reverse parking vehicle speed, according to the reverse parking vehicle speed extracted from the vehicle data, perform the dynamic parking performance test at each vehicle speed to obtain the dynamic parking performance test results at different vehicle speeds.

[0017] Optionally, when the test condition includes the forward parking vehicle speed, setting the motor controller in the controller host computer software to define the drive motor of the electric drive axle to rotate forward and performing the dynamic parking performance test of the electric drive axle includes:

[0018] Send a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the parking released state before the test;

[0019] Check through the observation window that the parking pawl and parking ratchet in the parking mechanism of the electric drive axle are in a separated state;

[0020] Perform the dynamic parking performance test of the electric drive axle. Set the motor controller in the controller host computer software to define the drive motor of the electric drive axle to rotate forward, corresponding to the forward direction of the vehicle;

[0021] Control the rotational speed of the drive motor of the electric drive axle simultaneously, and control the rotational speed of the drive motor of the electric drive axle to be n +1 , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +1 After operating stably for a preset duration, cut off the high voltage power supply to let the drive motor decelerate by free coasting;

[0022] Connect the wheel ends of the electric drive axle to the inertia device, and control the rotational speeds of the wheel ends on both sides of the electric drive axle to be greater than 0 through the inertia device;

[0023] Meanwhile, control the parking actuator to perform the parking engagement operation through the parking controller until the parking gear is fully engaged;

[0024] Send a parking release command to the parking actuator to release the parking; manually rotate the inertia device to randomly rotate a preset angle to make the teeth of the parking pawl and the parking ratchet engage;

[0025] When the rotational speed of the drive motor of the electric drive axle is n +1 , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +1 Under the test conditions, repeat the above actions until the quantity threshold is reached.

[0026] Optionally, when the working condition of the test conditions includes the parking vehicle speed in the reverse direction, perform the dynamic parking performance test under each vehicle speed condition according to the parking vehicle speed in the reverse direction extracted from the vehicle data, including:

[0027] Set the motor controller in the controller upper computer software, define the drive motor of the electric drive axle to rotate in reverse, and simultaneously control the rotational speed of the drive motor of the electric drive axle to the maximum vehicle speed; after operating stably for a preset duration, cut off the high voltage power supply to let the drive motor decelerate by free coasting;

[0028] Connect the wheel ends of the electric drive axle to the inertia device, and control the rotational speeds of the wheel ends on both sides of the electric drive axle to be greater than 0 through the inertia device;

[0029] Meanwhile, control the parking actuator to perform the parking engagement operation through the parking controller until the parking gear is fully engaged;

[0030] Send a parking release command to the parking actuator to release the parking; manually rotate the inertia device to randomly rotate a preset angle to make the teeth of the parking pawl and the parking ratchet engage;

[0031] After repeating the above actions until the quantity threshold is reached, disassemble and inspect the sample, record the sample status, and perform failure analysis on the failed samples.

[0032] Optionally, the dynamic parking durability test of the electric drive axle of the vehicle at different vehicle speeds includes:

[0033] Send a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the parking released state before the test;

[0034] Check through the observation window that the parking pawl and the parking ratchet in the parking mechanism of the electric drive axle are in a separated state;

[0035] When the actual vehicle is moving forward, set the motor controller in the upper computer software of the controller to define the drive motor of the electric drive axle to rotate forward; at the same time, control the rotational speed of the drive motor of the electric drive axle and the parking vehicle speed in the forward direction of the corresponding electric drive axle;

[0036] When the actual vehicle is moving backward, set the motor controller in the upper computer software of the controller to define the drive motor of the electric drive axle to rotate backward, and at the same time control the rotational speed of the drive motor of the electric drive axle and the parking vehicle speed in the reverse direction of the corresponding electric drive axle;

[0037] After running stably for a predetermined duration, cut off the high voltage power supply to make the drive motor coast and decelerate; connect the wheel ends of the electric drive axle to the inertia device, and control the rotational speeds of the wheel ends on both sides of the electric drive axle to be greater than 0 through the inertia device;

[0038] At the same time, control the parking actuator to perform the parking engagement operation through the parking controller until it is fully engaged in the parking gear;

[0039] Send a parking release command to the parking actuator to release the parking; manually rotate the inertia device to make it randomly rotate a preset angle;

[0040] Repeat the above actions until the quantity threshold is reached, and complete the dynamic parking durability test of the electric drive axle of the actual vehicle in different directions.

[0041] In a second aspect, the present application provides a reliability test device for dynamic parking of an electric drive axle, including: a test fixing device, an electric drive axle, a battery simulator, a motor controller, a parking controller, a parking actuator, an upper computer of the controller, a drive shaft, a rotational speed sensor, and an inertia device;

[0042] Among them, the test fixing device is used to fix the electric drive axle on the test platform;

[0043] The motor controller is connected to the battery simulator through a high-voltage wire harness and is connected to the parking actuator and the upper computer of the controller through a low-voltage wire harness, and is used to control the operation and shutdown of the drive motor on the electric drive axle;

[0044] The parking controller is connected to the parking actuator through a low-voltage wire harness and sends a parking command request to the parking actuator;

[0045] The battery simulator is used to provide working voltage and current for the motor controller and the parking controller;

[0046] The parking actuator is used to control the engagement of the parking pawl and the parking ratchet in the parking mechanism to be tested, so that the parking mechanism to be tested is locked at the target parking position;

[0047] The upper computer of the controller is connected to the motor controller and the parking controller through a low-voltage harness, contains software for monitoring the motor controller and the parking controller, and performs test configuration and operation through the user interface;

[0048] The rotational speed sensor is connected to the output end of the electric drive axle through a transmission shaft, measures the output rotational speed of the output end of the electric drive axle and the rotational speed of the inertia device, and records it in real time on the upper computer of the controller;

[0049] The inertia device is connected to the rotational speed sensor through a transmission shaft, and is used to simulate the inertia of a real vehicle and output rotational speed.

[0050] Optionally, the electric drive axle includes a bridge housing, a drive motor, a transmission assembly, a half shaft, and a parking mechanism.

[0051] In a third aspect, the present application provides a reliability test system for dynamic parking of an electric drive axle, and the system includes:

[0052] An information acquisition unit for reading the vehicle data of the test vehicle under a predefined dynamic parking test condition;

[0053] A test unit for performing a dynamic parking performance test and a durability test of the electric drive axle of the real vehicle at different vehicle speeds according to the test conditions under each dynamic parking test condition of the vehicle data, and recording the rotational speed data of the drive motor and the rotational speed sensor changing with time during the test;

[0054] A demand evaluation unit for obtaining the rotational speed values of the drive motor and the rotational speed sensor when the vehicle completely enters the parking gear from the rotational speed data, calculating the wheel-end vehicle speed of the electric drive axle, and judging whether the result of the dynamic parking performance test is qualified and whether the result of the dynamic parking durability test meets the dynamic parking reliability requirements based on the wheel-end vehicle speed of the electric drive axle.

[0055] The beneficial effects of the present invention are reflected in:

[0056] The above-provided reliability test method, device, and system for dynamic parking of an electric drive axle start from the dynamic verification requirement analysis of the parking mechanism of the electric drive axle, and in combination with the requirements of the real vehicle working conditions, develop a test device and scheme for the dynamic parking performance and durability of the electric drive axle, which can simulate the real vehicle at the bench verification stage, realize the dynamic parking performance and durability test of the electric drive axle under different working conditions, so as to determine the range of vehicle speeds within which the parking mechanism of the electric drive axle can achieve dynamic parking and ensure the safe stop of the real vehicle; it can avoid the safety risks existing in the vehicle parking test during the development process and reduce the complex installation process of the sample.

[0057] Meanwhile, the present invention can conduct bench tests on the performance and durability of the parking system during the early R & D process of the product, providing support for shortening the product development cycle and improving product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally denoted by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0059] Figure 1 It is a flowchart of a reliability test method for dynamic parking of an electric drive axle provided by the present invention;

[0060] Figure 2 It is a schematic structural diagram of a reliability test device for dynamic parking of an electric drive axle provided by the present invention;

[0061] Figure 3 It is a structural block diagram of a reliability test system for dynamic parking of an electric drive axle provided by the present invention;

[0062] In the figure: 1 - battery simulator; 2 - motor controller; 3 - electric drive axle; 4 - parking controller; 5 - parking actuator; 6 - controller host computer; 7 - speed sensor; 8 - test fixing device; 9 - drive shaft; 10 - inertia device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0063] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the following further details the present application in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0064] In order to overcome the deficiencies existing in the prior art, a reliability test method for dynamic parking of an electric drive axle provided in an embodiment of the present application is mainly applied to in-vehicle devices. The method can be applied to a terminal, or to a server, or to a vehicle system including a terminal and a server, and is implemented through the interaction between the terminal and the server. Among them, the terminal can be, but is not limited to, various personal computers, laptop computers, smart phones, tablet computers, etc.

[0065] The following embodiments take the vehicle side as an example and elaborate in detail on the design process of the method. Through the method proposed in the embodiments of the present invention, as Figure 1 shown. In one embodiment, a reliability test method for dynamic parking of an electric drive axle provided in an embodiment of the present invention, the method includes:

[0066] S1 Reads the vehicle's overall data when the test vehicle is under predefined dynamic parking test conditions;

[0067] S2 According to the test conditions under each dynamic parking test condition of the vehicle's overall data, conducts the dynamic parking performance test and durability test of the electric drive axle of the actual vehicle at different vehicle speeds, and records the rotational speed data of the drive motor and the rotational speed sensor changing with time during the test;

[0068] S3 Obtains the rotational speed values of the drive motor and the rotational speed sensor when the vehicle completely enters the parking gear from the rotational speed data, calculates the wheel-end vehicle speed of the electric drive axle, and determines whether the result of the dynamic parking performance test is qualified and whether the result of the dynamic parking durability test meets the dynamic parking reliability requirements based on the wheel-end vehicle speed of the electric drive axle.

[0069] In the above embodiment, the predefined dynamic parking test conditions in step S1 include: analyzing the historical dynamic parking data of the test vehicle under different conditions, obtaining the vehicle's overall data for dynamic parking, calculating the wheel-end inertia in combination with the vehicle model parameters, and formulating the dynamic parking test conditions, including: forward-direction parking vehicle speed, reverse-direction parking vehicle speed, and wheel-end inertia.

[0070] Optionally, analyze the dynamic parking data of the test vehicle on roads under different conditions, extract the vehicle speed data commonly used by the vehicle during dynamic parking, and at the same time calculate the wheel-end inertia according to the vehicle model parameters to formulate the dynamic parking test conditions, including: forward-direction parking vehicle speed V + (constituted by multiple vehicle speeds), reverse-direction parking vehicle speed V- (constituted by multiple vehicle speeds), and wheel-end inertia I b .

[0071] Install the tested electric drive axle (including the parking mechanism) onto the test platform through the test fixture, and conduct the dynamic parking performance and durability tests on the electric drive axle (including the parking mechanism).

[0072] During the dynamic parking performance and durability tests of the electric drive axle, the low-voltage systems of the actual vehicle motor controller and the parking controller are continuously powered, record the rotational speed data of the drive motor and the rotational speed of the rotational speed sensor changing with time, and read and record the rotational speed of the drive motor (judged according to the turning point of the drive motor rotational speed slope) and the rotational speed value of the rotational speed sensor when completely entering the parking gear.

[0073] In the above embodiment, before step S2 conducts the dynamic parking performance test and durability test of the electric drive axle of the actual vehicle at different vehicle speeds according to the test conditions under each dynamic parking test condition of the vehicle's overall data, it also includes: connecting the high- and low-voltage harnesses of the drive motor and the motor controller on the electric drive axle, and the low-voltage harnesses of the parking controller and the parking actuator, and installing the tested electric drive axle onto the test platform through the test fixture;

[0074] One output end of the electric drive axle is free, and the other output end is connected to a rotational speed sensor through a transmission shaft. At the same time, the rotational speed sensor is connected to the host computer of the controller through its own data transmission line for rotational speed signal transmission and feedback. The other end is connected to an inertia device that simulates the inertia of a real vehicle through a transmission shaft.

[0075] In the above embodiment, the step S2 of performing the dynamic parking performance test of the electric drive axle at different vehicle speeds of the real vehicle includes:

[0076] When the working condition of the test condition includes the parking vehicle speed in the forward direction, in the software of the host computer of the controller, set the motor controller to define the drive motor of the electric drive axle to rotate forward to perform the dynamic parking performance test of the electric drive axle; and, according to the parking vehicle speed in the forward direction extracted from the vehicle data, perform the dynamic parking performance test at each vehicle speed;

[0077] When the working condition of the test condition includes the parking vehicle speed in the reverse direction, according to the parking vehicle speed in the reverse direction extracted from the vehicle data, perform the dynamic parking performance test at each vehicle speed to obtain the dynamic parking performance test results at different vehicle speeds.

[0078] In the above embodiment, when the working condition of the test condition includes the parking vehicle speed in the forward direction, setting the motor controller in the software of the host computer of the controller to define the drive motor of the electric drive axle to rotate forward and performing the dynamic parking performance test of the electric drive axle includes:

[0079] Send a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the parking released state before the test;

[0080] Check through the observation window that the parking pawl and the parking ratchet in the parking mechanism of the electric drive axle are in the separated state;

[0081] Perform the dynamic parking performance test of the electric drive axle. In the software of the host computer of the controller, set the motor controller to define the drive motor of the electric drive axle to rotate forward, corresponding to the forward direction of the real vehicle;

[0082] At the same time, control the rotational speed of the drive motor of the electric drive axle. At the same time, control the rotational speed of the drive motor of the electric drive axle to be n

[0083] +1 corresponding to the forward direction parking vehicle speed V +1 +1 After stably operating for a predetermined time, cut off the high voltage power supply to make the drive motor coast and decelerate;

[0084] Connect the wheel end of the electric drive axle to the inertia device, and control the rotational speeds of both wheel ends of the electric drive axle to be greater than 0 through the inertia device;

[0085] At the same time, control the parking actuator to perform the parking engagement operation through the parking controller until it is fully engaged in the parking gear;

[0086] Send a parking release command to the parking actuator to release the parking; manually rotate the inertia device to randomly rotate it by a preset angle to engage the teeth of the parking pawl and the parking ratchet;

[0087] When the rotational speed of the drive motor of the electric drive axle is n +1 , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +1 Under the test conditions, repeat the above actions until the quantity threshold is reached.

[0088] In the above embodiment, when the working condition of the test conditions includes the parking vehicle speed in the reverse direction, and the parking vehicle speed in the reverse direction extracted according to the vehicle data, performing the dynamic parking performance test under each vehicle speed condition includes:

[0089] Set the motor controller in the controller upper computer software, define the drive motor of the electric drive axle to rotate in reverse, and at the same time control the rotational speed of the drive motor of the electric drive axle to the maximum vehicle speed; after running stably for a preset duration, cut off the high voltage to make the drive motor free-wheel and decelerate;

[0090] Connect the wheel end of the electric drive axle to the inertia device, and control the rotational speeds of the wheel ends on both sides of the electric drive axle to be greater than 0 through the inertia device;

[0091] At the same time, control the parking actuator to perform the parking engagement operation through the parking controller until it is fully engaged in the parking gear;

[0092] Send a parking release command to the parking actuator to release the parking; manually rotate the inertia device to randomly rotate it by a preset angle to engage the teeth of the parking pawl and the parking ratchet;

[0093] After repeating the above actions until the quantity threshold is reached, disassemble and inspect the sample, record the sample status, and perform failure analysis on the failed samples.

[0094] In step S2, performing the dynamic parking durability test of the electric drive axle of the vehicle at different vehicle speeds includes:

[0095] Send a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the released parking state before the test;

[0096] Check through the observation window that the parking pawl and the parking ratchet in the parking mechanism of the electric drive axle are in a separated state;

[0097] When the vehicle is moving forward, set the motor controller in the controller upper computer software to define the drive motor of the electric drive axle to rotate forward; at the same time, control the rotational speed of the drive motor of the electric drive axle and the corresponding parking vehicle speed in the forward direction of the electric drive axle;

[0098] When the vehicle is moving in reverse, set the motor controller in the controller upper computer software to define the drive motor of the electric drive axle to rotate in reverse, and at the same time control the rotational speed of the drive motor of the electric drive axle and the corresponding parking vehicle speed in the reverse direction of the electric drive axle;

[0099] After running stably for a preset duration, cut off the high-voltage power supply to allow the drive motor to coast and decelerate; connect the wheel end of the electric drive axle to the inertia device, and control the rotational speeds of the wheel ends on both sides of the electric drive axle to be greater than 0 through the inertia device;

[0100] At the same time, control the parking actuator to perform the parking engagement operation through the parking controller until it is fully engaged in the parking gear;

[0101] Send a parking release command to the parking actuator to release the parking; manually rotate the inertia device to randomly rotate it by a preset angle;

[0102] Repeat the above actions until the quantity threshold is reached to complete the dynamic parking durability test of the electric drive axle of the vehicle in different directions.

[0103] The test method proposed in the above step S2 mainly includes two aspects. One is the performance test, and the other is the durability test. Specifically, first, open an observation window at the electric drive axle housing above the meshing position of the parking pawl and the parking ratchet to facilitate the test personnel to analyze the test results;

[0104] Install and fix the test electric drive axle (including the parking mechanism) on the test platform through the test fixing device, and connect the high- and low-voltage wiring harnesses of the drive motor and the motor controller on the electric drive axle, as well as the low-voltage wiring harnesses of the parking controller and the parking actuator. One output end of the electric drive axle (including the parking mechanism) is free, and the other output end of the electric drive axle (including the parking mechanism) is connected to the rotational speed sensor through a drive shaft. At the same time, the rotational speed sensor is connected to the controller host computer through its own data transmission line for rotational speed signal transmission and feedback.

[0105] The other end of the rotational speed sensor is connected to the inertia device that simulates the inertia of the actual vehicle through a drive shaft.

[0106] Before the test, turn on the power supplies of the motor controller and the parking controller, set the output DC power supply voltage of the battery simulator to 540V, set the drive motor working mode of the motor controller to speed control in the controller host computer software, set the power supply working voltage of the parking controller to 24V in the controller host computer software, and send a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the parking released state before the test, that is, the output end of the electric drive axle can rotate freely. At this time, through the observation window, the separated state of the parking pawl and the parking ratchet in the parking mechanism of the electric drive axle can be seen.

[0107] Start the dynamic parking performance test of the electric drive axle. In the controller host computer software, set the motor controller to define the drive motor of the electric drive axle to rotate forward (corresponding to the forward direction of the actual vehicle), and at the same time control the rotational speed of the drive motor of the electric drive axle to be n +1 corresponding to the forward parking vehicle speed V of the electric drive axle +1, after running stably for 1 minute, cut off the high voltage to make the drive motor coast and decelerate. At this time, since the inertia device is connected to the wheel ends of the electric drive axle, this inertia device can ensure that the rotational speeds of the wheel ends on both sides of the electric drive axle will not drop to 0 instantaneously. At the same time, the upper computer of the application controller controls the parking actuator to perform the parking gear engagement operation through the parking controller until the parking gear is fully engaged (until the sample comes to a complete stop). At this time, through the observation window at the electric drive axle housing, it can be checked whether the parking pawl and the parking ratchet are engaged with each other. If they are engaged, it is considered that the dynamic parking performance test of the electric drive axle is qualified at this vehicle speed; otherwise, it is regarded as unqualified for the dynamic parking performance test at this vehicle speed.

[0108] Then, perform the parking release operation in the upper computer software of the controller. Send a parking release command to the parking actuator through the parking controller to release the parking. Manually rotate the inertia device to make it randomly rotate a certain angle. The purpose is that during the next dynamic parking test, the parking pawl and the teeth of other parking ratchets can be engaged to facilitate comprehensive assessment.

[0109] When the rotational speed of the drive motor of the electric drive axle is n +1 , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +1 Under the test conditions, repeat the above operations no less than 3 times, then the dynamic parking performance test at this vehicle speed is completed.

[0110] During the dynamic parking performance test of the electric drive axle, the low-voltage systems of the motor controller and the parking controller are continuously powered. Record the data of the rotational speed of the drive motor and the rotational speed of the rotational speed sensor changing with time, read and record the rotational speed of the drive motor when fully parked in the parking gear (judged according to the turning point of the rotational speed slope of the drive motor) and the rotational speed value of the rotational speed sensor. Calculate the wheel end vehicle speed value of the electric drive axle through the recorded rotational speed value of the drive motor and the rotational speed value of the rotational speed sensor, so as to clarify whether the dynamic parking performance requirements are met at a specific vehicle speed for the designer.

[0111] The dynamic parking performance test method of the electric drive axle of the present invention further includes:

[0112] The dynamic parking performance tests under various vehicle speed conditions of the forward direction parking vehicle speed V + (constituted by multiple vehicle speeds), that is, when the rotational speed of the drive motor of the electric drive axle is n +2 , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +2； When the rotational speed of the drive motor of the electric drive axle is n +3 , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +3； When the rotational speed of the drive motor of the electric drive axle is n +4 , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +4 and so on. That is to say, the working conditions in the test conditions of the dynamic parking performance test include the forward direction parking vehicle speed V +For each vehicle speed (composed of multiple vehicle speeds), the test results of the dynamic parking performance of these vehicle speeds are respectively evaluated for compliance.

[0113] The method for testing the dynamic parking performance of the electric drive axle of the present invention further includes:

[0114] Experimental verification of the reverse parking vehicle speed for the dynamic parking performance test of the electric drive axle, the method is the same as the way of verifying the forward parking vehicle speed, only the test conditions are different. According to the reverse parking vehicle speed V extracted from the vehicle data + (For each of the multiple vehicle speeds) the dynamic parking performance test under each vehicle speed condition, that is, the rotational speed of the drive motor of the electric drive axle is n -1 , corresponding to the forward parking vehicle speed V of the electric drive axle -1 ; the rotational speed of the drive motor of the electric drive axle is n -2 , corresponding to the forward parking vehicle speed V of the electric drive axle -2 ; the rotational speed of the drive motor of the electric drive axle is n -3 , corresponding to the forward parking vehicle speed V of the electric drive axle -3 and so on. That is to say, the working conditions in the test conditions of the dynamic parking performance test include the reverse parking vehicle speed V - for each of the multiple vehicle speeds, and the test results of the dynamic parking performance of these vehicle speeds are respectively evaluated for compliance.

[0115] The method for testing the dynamic parking durability of the electric drive axle of the present invention includes:

[0116] Install and fix the tested electric drive axle (including the parking mechanism) on the test platform through the test fixing device, and connect the high- and low-voltage wiring harnesses of the drive motor, motor controller, parking controller, and parking actuator low-voltage wiring harness on the electric drive axle. One output end of the electric drive axle (including the parking mechanism) is free, and the other output end of the electric drive axle (including the parking mechanism) is connected to the rotational speed sensor through a drive shaft. At the same time, the rotational speed sensor is connected to the controller upper computer through its own data transmission line for rotational speed signal transmission and feedback, and the other end of the rotational speed sensor is connected to the inertia device simulating the vehicle inertia through the drive shaft.

[0117] Before the test, turn on the power of the motor controller and the parking controller, set the output DC power supply voltage of the battery simulator to 540V, set the drive motor working mode of the motor controller to speed control in the controller upper computer software, set the power supply working voltage of the parking controller to 24V in the controller upper computer software, and send a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the parking release state before the test, that is, the output end of the electric drive axle can rotate freely.

[0118] Start the dynamic parking durability test of the electric drive axle. In the upper computer software of the controller, set the motor controller to define the drive motor of the electric drive axle to rotate forward (corresponding to the forward direction of the actual vehicle), and at the same time control the rotational speed of the drive motor of the electric drive axle to be n +m , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +m (This vehicle speed is the maximum limit vehicle speed of the product design ability). After stable operation for 1 minute, cut off the high voltage power, and let the drive motor coast and decelerate. At this time, due to the inertia device connected to the wheel end of the electric drive axle, this inertia device can ensure that the rotational speeds of the wheel ends on both sides of the electric drive axle will not drop to 0 instantaneously. At the same time, the upper computer of the application controller controls the parking actuator to execute the parking gear engagement operation through the parking controller until it is fully engaged in the parking gear (until the sample is completely stationary and terminated).

[0119] Then, perform the parking release operation in the upper computer software of the controller. Send a parking release command to the parking actuator through the parking controller to release the parking. Manually rotate the inertia device so that it rotates randomly by a certain angle. The purpose is that during the next dynamic parking test, the parking pawl and the teeth of other parking ratchets can be engaged to facilitate comprehensive assessment. Repeat and complete the number of times specified by the design target value. After the test, the sample should be disassembled and inspected, and the sample status should be recorded. If there is a failure, failure analysis should be carried out. If necessary, metallographic analysis should be carried out on relevant parts.

[0120] The dynamic parking durability test method of the electric drive axle of the present invention also includes:

[0121] Install and fix the tested electric drive axle (including the parking mechanism) on the test platform through the test fixing device, and connect the high- and low-voltage wiring harnesses of the drive motor, motor controller, parking controller, and parking actuator on the electric drive axle. One output end of the electric drive axle (including the parking mechanism) is free, and the other output end of the electric drive axle (including the parking mechanism) is connected to the rotational speed sensor through a drive shaft. At the same time, the rotational speed sensor is connected to the upper computer of the controller through its own data transmission line for rotational speed signal transmission and feedback. The other end of the rotational speed sensor is connected to the inertia device that simulates the inertia of the actual vehicle through a drive shaft.

[0122] Before the test, turn on the power supplies of the motor controller and the parking controller, set the output DC power supply voltage of the battery simulator to 540V, set the drive motor working mode of the motor controller to speed control in the upper computer software of the controller, set the power supply working voltage of the parking controller to 24V in the upper computer software of the controller, and send a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the parking release state before the test, that is, the output end of the electric drive axle can rotate freely.

[0123] Start the dynamic parking durability test of the electric drive axle. In the upper computer software of the controller, set the motor controller to define the drive motor of the electric drive axle to rotate in reverse (corresponding to the reverse direction of the actual vehicle), and at the same time control the rotational speed of the drive motor of the electric drive axle to be n-m corresponding to the parking vehicle speed V in the reverse direction of the electric drive axle -m (This vehicle speed is the maximum limit speed of the product design capacity). After operating stably for 1 minute, cut off the high-voltage power supply to make the drive motor coast and decelerate. At this time, due to the inertia device connected to the wheel ends of the electric drive axle, this inertia device can ensure that the rotational speeds of the wheel ends on both sides of the electric drive axle will not drop to 0 instantaneously. At the same time, the upper computer of the application controller controls the parking actuator to perform the parking gear engagement operation through the parking controller until the parking gear is fully engaged (until the sample comes to a complete stop).

[0124] Then, perform the parking release operation in the upper computer software of the controller. Send a parking release command to the parking actuator through the parking controller to release the parking. Manually rotate the inertia device to make it rotate randomly by a certain angle. The purpose is that during the next dynamic parking test, the parking pawl and the teeth of other parking ratchets can be engaged to facilitate a comprehensive assessment. Repeat and complete the number of times specified by the design target value. After the test, the sample should be disassembled and inspected, and the sample status should be recorded. In case of failure, failure analysis should be carried out. If necessary, metallographic analysis should be carried out on relevant parts.

[0125] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are displayed in sequence according to the arrows, these steps do not necessarily have to be executed in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps does not have a strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages do not necessarily have to be executed at the same time, but can be executed at different times. The execution order of these steps or stages does not necessarily have to be sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0126] In one embodiment, the present invention also provides a reliability test device for dynamic parking of an electric drive axle, including: a battery simulator 1, a motor controller 2, an electric drive axle 3, a parking controller 4, a parking actuator 5, an upper computer 6 of the controller, a speed sensor 7, a test fixing device 8, a drive shaft 9, and an inertia device 10; the electric drive axle includes a bridge housing, a drive motor, a transmission assembly, a half shaft, and a parking mechanism. The test device is shown in the appendix Figure 2 .

[0127] Among them, the test fixing device is used to fix the electric drive axle on the test platform;

[0128] The motor controller is connected to the battery simulator through a high-voltage wire harness and is connected to the parking actuator and the upper computer of the controller through a low-voltage wire harness, and is used to control the operation and shutdown of the drive motor on the electric drive axle;

[0129] The parking controller is connected to the parking actuator through a low-voltage harness and sends a parking instruction request to the parking actuator;

[0130] The battery simulator is used to provide working voltage and current for the motor controller and the parking controller; in this embodiment, the battery simulator replaces the power battery.

[0131] The parking actuator is used to control the engagement of the parking pawl and the parking ratchet in the parking mechanism to be tested, so that the parking mechanism to be tested is locked at the target parking position;

[0132] The controller host computer is connected to the motor controller and the parking controller through a low-voltage harness, contains software for monitoring the motor controller and the parking controller, and performs test configuration and operation through the user interface;

[0133] The speed sensor is connected to the output end of the electric drive axle through a transmission shaft, measures the output speed of the output end of the electric drive axle and the speed of the inertia device, and records them in real time on the controller host computer;

[0134] The inertia device is connected to the speed sensor through a transmission shaft, is used to simulate the inertia of a real vehicle, and outputs speed.

[0135] Parking controller: Connected to the parking actuator through a low-voltage harness, and sends a parking instruction request to the parking actuator;

[0136] Speed sensor: Connected to the output end of the electric drive axle through a transmission shaft, measures the output speed of the output end of the electric drive axle and the speed of the inertia device, and records them in real time on the controller host computer;

[0137] Inertia device: Connected to the speed sensor through a transmission shaft, simulates the inertia of a real vehicle, and is used to stably output speed.

[0138] Based on the above specific implementation solutions, the present application provides the following embodiments. The embodiments of the present invention provide a test method for the dynamic parking performance and durability of an electric drive axle, including:

[0139] Analyze the dynamic parking data of the test vehicle on roads under different working conditions, extract the vehicle speed data commonly used by the whole vehicle during dynamic parking, and calculate the wheel end inertia according to the vehicle type parameters to formulate dynamic parking test conditions, including: forward direction parking vehicle speed V + (constituted by multiple vehicle speeds), reverse direction parking vehicle speed V- (constituted by multiple vehicle speeds) and wheel end inertia I b .

[0140] First, open an observation window at the electric drive axle housing above the engagement position of the parking pawl and the parking ratchet to facilitate the test personnel to analyze the test results;

[0141] The tested electric drive axle (including the parking mechanism) is installed and fixed on the test platform through the test fixture, and the high- and low-voltage wiring harnesses of the drive motor and motor controller on the electric drive axle, as well as the low-voltage wiring harnesses of the parking controller and parking actuator, are connected. One output end of the electric drive axle (including the parking mechanism) is free, and the other output end of the electric drive axle (including the parking mechanism) is connected to the speed sensor through a drive shaft. At the same time, the speed sensor is connected to the upper computer of the controller through its own data transmission line for speed signal transmission and feedback. The other end of the speed sensor is connected to the inertia device that simulates the inertia of the actual vehicle through a drive shaft.

[0142] Before the test, turn on the power of the motor controller and the parking controller, set the output DC power voltage of the battery simulator to 540V, set the drive motor working mode of the motor controller to speed control in the upper computer software of the controller, set the power supply working voltage of the parking controller to 24V in the upper computer software of the controller, and send a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the parking release state before the test, that is, the output end of the electric drive axle can rotate freely. At this time, through the observation window, the separated state of the parking pawl and the parking ratchet in the parking mechanism of the electric drive axle can be seen.

[0143] Start the dynamic parking performance test of the electric drive axle. In the upper computer software of the controller, set the motor controller to define the drive motor of the electric drive axle to rotate forward (corresponding to the forward direction of the actual vehicle), and at the same time control the rotation speed of the drive motor of the electric drive axle to be n +1 , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +1 . After running stably for 1 minute, cut off the high voltage to make the drive motor coast and decelerate. At this time, because the inertia device is connected to the wheel end of the electric drive axle, this inertia device can ensure that the rotational speeds of the two wheel ends of the electric drive axle will not drop to 0 instantaneously. At the same time, the upper computer of the application controller controls the parking actuator to perform the parking engagement operation through the parking controller until it is fully engaged in the parking gear (terminating until the sample is completely stationary). At this time, through the observation window at the electric drive axle housing, it can be checked whether the parking pawl and the parking ratchet are engaged with each other. If they are engaged, it is considered that the dynamic parking performance test of the electric drive axle is qualified at this vehicle speed; otherwise, it is regarded as unqualified for the dynamic parking performance test at this vehicle speed.

[0144] Then, perform the parking release operation in the upper computer software of the controller, send a parking release command to the parking actuator through the parking controller to release the parking, and manually rotate the inertia device to make it rotate randomly by a certain angle. The purpose is that in the next dynamic parking test, the parking pawl and the teeth of other parking ratchets can be engaged to facilitate comprehensive assessment.

[0145] When the rotational speed of the drive motor of the electric drive axle is n +1 , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +1Under the test conditions, repeat the above operations no less than 3 times, then the dynamic parking performance test at this vehicle speed is completed.

[0146] During the dynamic parking performance test of the electric drive axle, the low-voltage systems of the motor controller and the parking controller are continuously powered. Record the data of the driving motor speed and the speed of the speed sensor changing with time, read and record the driving motor speed (judged according to the turning point of the driving motor speed slope) and the speed value of the speed sensor when fully parked in the parking gear. Through the recorded driving motor speed value and the speed value of the speed sensor, calculate the vehicle speed value at the wheel end of the electric drive axle, and then determine whether the dynamic parking performance requirements are met at the specified vehicle speed for the designer.

[0147] The dynamic parking performance test method of the electric drive axle of the present invention further includes:

[0148] The forward parking vehicle speed V extracted according to the vehicle data + (Multiple vehicle speeds) The dynamic parking performance test under each vehicle speed condition, that is, the driving motor speed of the electric drive axle is n +2 , corresponding to the forward parking vehicle speed V of the electric drive axle +2； The driving motor speed of the electric drive axle is n +3 , corresponding to the forward parking vehicle speed V of the electric drive axle +3； The driving motor speed of the electric drive axle is n +4 , corresponding to the forward parking vehicle speed V of the electric drive axle +4 , and so on. That is to say, the working conditions in the test conditions of the dynamic parking performance test include the forward parking vehicle speed V + (Multiple vehicle speeds) Each vehicle speed, and evaluate whether the test results of the dynamic parking performance of these vehicle speeds are qualified respectively.

[0149] The dynamic parking performance test method of the electric drive axle of the present invention further includes:

[0150] The test verification of the reverse parking vehicle speed in the dynamic parking performance test of the electric drive axle is the same as the method of verifying the forward parking vehicle speed, only the test conditions are different. The reverse parking vehicle speed V extracted according to the vehicle data + (Multiple vehicle speeds) The dynamic parking performance test under each vehicle speed condition, that is, the driving motor speed of the electric drive axle is n -1 , corresponding to the forward parking vehicle speed V of the electric drive axle -1 ; the driving motor speed of the electric drive axle is n -2 , corresponding to the forward parking vehicle speed V of the electric drive axle -2 ; the driving motor speed of the electric drive axle is n -3 , corresponding to the forward parking vehicle speed V of the electric drive axle -3 , and so on. That is to say, the working conditions in the test conditions of the dynamic parking performance test include the reverse parking vehicle speed V -For each vehicle speed (composed of multiple vehicle speeds), the dynamic parking performance test results of these vehicle speeds are respectively evaluated for qualification.

[0151] The dynamic parking durability test method for the electric drive axle of the present invention includes:

[0152] Install and fix the tested electric drive axle (including the parking mechanism) on the test platform through the test fixing device, and connect the high- and low-voltage wiring harnesses of the drive motor and the motor controller on the electric drive axle, as well as the low-voltage wiring harnesses of the parking controller and the parking actuator. One output end of the electric drive axle (including the parking mechanism) is free, and the other output end of the electric drive axle (including the parking mechanism) is connected to the rotational speed sensor through a drive shaft. At the same time, the rotational speed sensor is connected to the controller host computer through its own data transmission line for rotational speed signal transmission and feedback. The other end of the rotational speed sensor is connected to the inertia device that simulates the inertia of the actual vehicle through a drive shaft.

[0153] Before the test, turn on the power supplies of the motor controller and the parking controller, set the output DC power supply voltage of the battery simulator to 540V, set the drive motor working mode of the motor controller to speed control in the controller host computer software, set the power supply working voltage of the parking controller to 24V in the controller host computer software, and send a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the parking released state before the test, that is, the output end of the electric drive axle can rotate freely.

[0154] Start the dynamic parking durability test of the electric drive axle. In the controller host computer software, set the motor controller to define the drive motor of the electric drive axle to rotate forward (corresponding to the forward direction of the actual vehicle), and at the same time control the rotational speed of the drive motor of the electric drive axle to be n +m , corresponding to the forward direction parking vehicle speed V +m (this vehicle speed is the limit maximum vehicle speed of the product design ability). After stable operation for 1 minute, cut off the high voltage, and let the drive motor coast and decelerate. At this time, because the inertia device is connected to the wheel ends of the electric drive axle, this inertia device can ensure that the rotational speeds of the two wheel ends of the electric drive axle will not drop to 0 instantaneously. At the same time, the controller host computer is used to control the parking actuator to perform the parking engagement operation through the parking controller until it is fully engaged in the parking gear (terminating until the sample is completely stationary).

[0155] Then, perform the parking release operation in the controller host computer software, send a parking release command to the parking actuator through the parking controller to release the parking, and manually rotate the inertia device to make it rotate randomly by a certain angle. The purpose is that in the next dynamic parking test, the parking pawl and the teeth of other parking ratchets can be engaged to facilitate comprehensive assessment. Repeat and complete the number of times specified by the design target value. After the test, the sample should be disassembled and inspected, and the sample status should be recorded. If there is a failure, failure analysis should be carried out. If necessary, metallographic analysis should be carried out on relevant parts.

[0156] The dynamic parking durability test method for the electric drive axle of the present invention further includes:

[0157] Install and fix the tested electric drive axle (including the parking mechanism) on the test platform through the test fixture, and connect the high- and low-voltage wiring harnesses of the drive motor, motor controller, parking controller, and parking actuator low-voltage wiring harness on the electric drive axle. One output end of the electric drive axle (including the parking mechanism) is free, and the other output end of the electric drive axle (including the parking mechanism) is connected to the speed sensor through a drive shaft. At the same time, the speed sensor is connected to the controller host computer through its own data transmission line for speed signal transmission and feedback. The other end of the speed sensor is connected to the inertia device that simulates the inertia of the actual vehicle through a drive shaft.

[0158] Before the test, turn on the power of the motor controller and the parking controller, set the output DC power supply voltage of the battery simulator to 540V, set the drive motor working mode of the motor controller to speed control in the controller host computer software, set the power supply working voltage of the parking controller to 24V in the controller host computer software, and send a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the parking release state before the test, that is, the output end of the electric drive axle can rotate freely.

[0159] Start the dynamic parking durability test of the electric drive axle. In the controller host computer software, set the motor controller to define the drive motor of the electric drive axle to reverse (corresponding to the reverse direction of the actual vehicle), and at the same time control the speed of the drive motor of the electric drive axle to be n -m , corresponding to the parking vehicle speed V -m (this vehicle speed is the maximum limit vehicle speed of the product design capacity). After stable operation for 1 minute, cut off the high voltage to make the drive motor coast and decelerate. At this time, because the inertia device is connected to the wheel end of the electric drive axle, this inertia device can ensure that the rotational speeds of both wheel ends of the electric drive axle will not drop to 0 instantaneously. At the same time, the controller host computer is used to control the parking actuator to perform the parking engagement operation through the parking controller until the parking gear is fully engaged (until the sample comes to a complete stop).

[0160] Then, perform a parking release operation in the controller host computer software, send a parking release command to the parking actuator through the parking controller to release the parking, and manually rotate the inertia device to make it rotate randomly by a certain angle. The purpose is that during the next dynamic parking test, the parking pawl and the teeth of other parking ratchets can be engaged to facilitate comprehensive assessment. Repeat and complete the number of times specified by the design target value. After the test, the sample should be disassembled and inspected, and the sample status should be recorded. If there is a failure, a failure analysis should be carried out. If necessary, a metallographic analysis should be carried out on the relevant parts.

[0161] Based on the same inventive concept, an embodiment of the present application also provides a reliability test system for the dynamic parking of an electric drive axle for implementing the reliability test method for the dynamic parking of an electric drive axle involved above. The solution provided by this system for solving problems is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the reliability test system for the dynamic parking of an electric drive axle provided below can refer to the limitations on the reliability test method for the dynamic parking of an electric drive axle in the above text, and will not be repeated here.

[0162] In one embodiment, a reliability test system for the dynamic parking of an electric drive axle is provided, as Figure 3 shown, which includes an information acquisition unit 210, a test unit 220, and a requirement evaluation unit 230, where:

[0163] The information acquisition unit 210 is configured to read the vehicle data of the test vehicle under a predefined dynamic parking test condition;

[0164] The test unit 220 is configured to perform a dynamic parking performance test and a durability test of the electric drive axle of the actual vehicle at different vehicle speeds according to the test conditions under each dynamic parking test condition of the vehicle data, and record the rotational speed data of the drive motor speed and the rotational speed sensor changing with time during the test;

[0165] The requirement evaluation unit 230 is configured to obtain the rotational speed values of the drive motor and the rotational speed sensor when the vehicle completely enters the parking gear from the rotational speed data, calculate the wheel-end vehicle speed of the electric drive axle, and determine whether the result of the dynamic parking performance test is qualified and whether the result of the dynamic parking durability test meets the dynamic parking reliability requirements based on the wheel-end vehicle speed of the electric drive axle.

[0166] It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0167] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A reliability test method for dynamic parking of an electric drive axle, characterized in that, The method includes: Reading the vehicle data of the test vehicle under pre-defined dynamic parking test conditions; According to the test conditions under each dynamic parking test condition of the vehicle data, performing the dynamic parking performance test and durability test of the electric drive axle of the vehicle at different vehicle speeds, and recording the rotational speed data of the drive motor speed and the rotational speed sensor changing with time during the test; Obtaining the rotational speed values of the drive motor and the rotational speed sensor when the vehicle completely enters the parking gear from the rotational speed data, calculating the wheel-end vehicle speed of the electric drive axle, and judging whether the result of the dynamic parking performance test is qualified and whether the result of the dynamic parking durability test meets the dynamic parking reliability requirements based on the wheel-end vehicle speed of the electric drive axle.

2. The method according to claim 1, characterized in that, The pre-definition of the dynamic parking test conditions includes: analyzing the historical dynamic parking data of the test vehicle under different conditions, obtaining the vehicle data of dynamic parking, calculating the wheel-end inertia in combination with the vehicle type parameters, and formulating the dynamic parking test conditions, including: the parking vehicle speed in the forward direction, the parking vehicle speed in the reverse direction, and the wheel-end inertia.

3. The method according to claim 2, wherein, Before performing the dynamic parking performance test and durability test of the electric drive axle of the vehicle at different vehicle speeds according to the test conditions under each dynamic parking test condition of the vehicle data, it further includes: connecting the high-voltage and low-voltage wiring harnesses of the drive motor, motor controller, parking controller, and parking actuator on the electric drive axle, and installing the tested electric drive axle to the test platform through the test fixture; One output end of the electric drive axle is free, and the other output end is connected to the rotational speed sensor through a drive shaft. At the same time, the rotational speed sensor is connected to the controller upper computer through its own data transmission line for rotational speed signal transmission and feedback, and the other end is connected to the inertia device simulating the vehicle inertia through a drive shaft.

4. The method according to claim 1, wherein Performing the dynamic parking performance test of the electric drive axle of the vehicle at different vehicle speeds includes: When the working condition of the test conditions includes the parking vehicle speed in the forward direction, setting the motor controller in the controller upper computer software to define the drive motor of the electric drive axle to rotate forward, and performing the dynamic parking performance test of the electric drive axle; and, according to the parking vehicle speed in the forward direction extracted from the vehicle data, performing the dynamic parking performance test at each vehicle speed; When the working condition of the test conditions includes the parking vehicle speed in the reverse direction, performing the dynamic parking performance test at each vehicle speed according to the parking vehicle speed in the reverse direction extracted from the vehicle data to obtain the dynamic parking performance test results at different vehicle speeds.

5. The method according to claim 4, wherein When the working condition of the test conditions includes the parking vehicle speed in the forward direction, setting the motor controller in the controller upper computer software to define the drive motor of the electric drive axle to rotate forward and performing the dynamic parking performance test of the electric drive axle includes: Sending a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the parking released state before the test; Checking through the observation window that the parking pawl and parking ratchet in the parking mechanism of the electric drive axle are in a separated state; Performing the dynamic parking performance test of the electric drive axle, setting the motor controller in the controller upper computer software to define the drive motor of the electric drive axle to rotate forward, corresponding to the forward direction of the vehicle; Control the rotational speed of the drive motor of the electric drive axle simultaneously, and control the rotational speed of the drive motor of the electric drive axle to be n +1 , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +1 , after running stably for a predetermined duration, cut off the high voltage power supply to make the drive motor coast and decelerate; Connecting the wheel end of the electric drive axle to the inertia device, and controlling the rotational speeds of both wheel ends of the electric drive axle to be greater than 0 through the inertia device; At the same time, controlling the parking actuator to perform the parking gear engagement operation through the parking controller until it is completely engaged in the parking gear; Send a parking release command to the parking actuator to release the parking; manually rotate the inertia device to randomly rotate a preset angle, so that the teeth of the parking pawl and the parking ratchet are engaged; When the rotational speed of the drive motor of the electric drive axle is n +1 , corresponding to the parking vehicle speed V in the forward direction of the electric drive axle +1 Under the test conditions, repeat the above actions until the quantity threshold is reached.

6. The method according to claim 4, wherein When the working condition of the test condition includes the parking vehicle speed in the reverse direction, and the parking vehicle speed in the reverse direction is extracted according to the vehicle data, the dynamic parking performance test under each vehicle speed condition includes: Set the motor controller in the controller upper computer software, define the drive motor of the electric drive axle to rotate in reverse, and at the same time control the speed of the drive motor of the electric drive axle to the maximum vehicle speed; after stable operation for a preset duration, cut off the high voltage, so that the drive motor free slides and decelerates; Connect the wheel end of the electric drive axle to the inertia device, and control the rotational speeds of the two wheel ends of the electric drive axle to be greater than 0 through the inertia device; At the same time, control the parking actuator to perform the parking engagement operation through the parking controller until it is fully engaged in the parking gear; Send a parking release command to the parking actuator to release the parking; manually rotate the inertia device to randomly rotate a preset angle, so that the teeth of the parking pawl and the parking ratchet are engaged; After repeating the above actions to the quantity threshold, disassemble and inspect the sample, record the sample status, and perform failure analysis on the failed samples.

7. The method according to claim 4, wherein The dynamic parking durability test of the electric drive axle of the vehicle at different vehicle speeds includes: Send a parking release command to the parking actuator through the parking controller to ensure that the parking mechanism is in the released parking state before the test; Check through the observation window that the parking pawl and the parking ratchet in the parking mechanism of the electric drive axle are in the separated state; When the vehicle is moving forward, set the motor controller in the controller upper computer software to define the drive motor of the electric drive axle to rotate forward; at the same time, control the rotational speed of the drive motor of the electric drive axle and the corresponding parking vehicle speed in the forward direction of the electric drive axle; When the vehicle is moving in reverse, set the motor controller in the controller upper computer software to define the drive motor of the electric drive axle to rotate in reverse, and at the same time control the rotational speed of the drive motor of the electric drive axle and the corresponding parking vehicle speed in the reverse direction of the electric drive axle; After stable operation for a preset duration, cut off the high voltage, so that the drive motor free slides and decelerates; connect the wheel end of the electric drive axle to the inertia device, and control the rotational speeds of the two wheel ends of the electric drive axle to be greater than 0 through the inertia device; At the same time, control the parking actuator to perform the parking engagement operation through the parking controller until it is fully engaged in the parking gear; Send a parking release command to the parking actuator to release the parking; manually rotate the inertia device to randomly rotate a preset angle; After repeating the above actions to the quantity threshold, complete the dynamic parking durability test of the electric drive axle of the vehicle in different directions.

8. A reliability test device for dynamic parking of an electric drive axle, characterized in that, It includes: Test fixture, electric drive axle, battery simulator, motor controller, parking controller, parking actuator, controller upper computer, drive shaft, speed sensor and inertia device; Among them, the test fixture is used to fix the electric drive axle on the test platform; The motor controller is connected to the battery simulator through a high-voltage wire harness, and is connected to the parking actuator and the controller upper computer through a low-voltage wire harness, and is used to control the operation and shutdown of the drive motor on the electric drive axle; The parking controller is connected to the parking actuator through a low-voltage wire harness and sends a parking command request to the parking actuator; The battery simulator is used to provide working voltage and current for the motor controller and the parking controller; The parking actuator is used to control the engagement of the parking pawl and the parking ratchet in the parking mechanism to be tested, so that the parking mechanism to be tested is locked at the target parking position; The controller host computer is connected to the motor controller and the parking controller through a low-voltage harness, contains software for monitoring the motor controller and the parking controller, and performs test configuration and operation through the user interface; The speed sensor is connected to the output end of the electric drive axle through a drive shaft, measures the output speed of the output end of the electric drive axle and the speed of the inertia device, and records it in real time on the controller host computer; The inertia device is connected to the speed sensor through a drive shaft, and is used to simulate the inertia of the actual vehicle and output speed; 9. The device according to claim 8, characterized in that, The electric drive axle includes a bridge housing, a drive motor, a transmission assembly, a half shaft and a parking mechanism; 10. A reliability test system for dynamic parking of an electric drive axle, characterized in that, The system includes: An information acquisition unit for reading the vehicle data of the test vehicle under the predefined dynamic parking test conditions; A test unit for performing the dynamic parking performance test and durability test of the electric drive axle of the actual vehicle at different vehicle speeds according to the test conditions of each dynamic parking test condition of the vehicle data, and recording the speed data of the drive motor speed and the speed sensor changing with time during the test; A requirement evaluation unit for obtaining the speed values of the drive motor and the speed sensor when the vehicle completely enters the parking gear from the speed data, calculating the wheel-end vehicle speed of the electric drive axle, and judging whether the result of the dynamic parking performance test is qualified and whether the result of the dynamic parking durability test meets the dynamic parking reliability requirements based on the wheel-end vehicle speed of the electric drive axle.

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