Reliability bench test method and device for electric drive axle for new energy vehicle

Abstract

The invention discloses an electric drive bridge reliability bench test method and device for a new energy vehicle, and belongs to the technical field of electric drive bridge bench tests. A target electric drive axle is driven by testing the rotating speed and torque, multi-direction loads are applied to an axle housing of the target electric drive axle based on an action excitation spectrum generated by a road surface load spectrum, the reliability of the target electric drive axle is determined according to real-time monitoring signals in the testing process, and the actual working condition of the electric drive axle in operation is tested under the simulated actual comprehensive load. The method has the effects of short detection period and real reliability, and solves the problem that the reliability of the electric drive axle under extreme conditions cannot be truly detected by adopting a whole vehicle test.

Description

Technical Field

[0001] The invention relates to a reliability bench test method and device for an electric drive axle for a new energy vehicle, belonging to the technical field of electric drive axle bench test. Background Art

[0002] As one of the key components of new energy commercial vehicles, the electric drive axle is responsible for transmitting the power generated by the motor to the wheels. Its performance directly affects the vehicle's acceleration performance, energy utilization and safety, so it plays a vital role.

[0003] At present, the reliability verification of electric drive axles is mainly carried out on the whole vehicle as the carrier, and the whole vehicle reliability verification is carried out on the user road or reinforced road surface of the test site, or supplemented by bench testing to verify the reliability. The two tests are independent of each other, and the whole vehicle reliability test cycle is long and the cost is high. It is impossible to test the actual comprehensive load of the electric drive axle, such as vertical force and longitudinal braking force, and it is also impossible to conduct a comprehensive and effective verification of the reliability of the electric drive axle including the motor and gear shift mechanism under the application of the comprehensive load. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a reliability bench test method and device for an electric drive axle for a new energy vehicle, which can simulate the actual working conditions of the electric drive axle in operation under the actual comprehensive load, and has the effect of short detection cycle and real reliability, thus solving the problem that the reliability of the electric drive axle under extreme conditions cannot be truly detected by using whole vehicle tests.

[0005] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions: On one hand, the present invention provides a reliability bench test method for an electric drive axle for a new energy vehicle, comprising: generating an action excitation spectrum based on a pre-acquired road load spectrum of an electric drive axle of the same model as a target electric drive axle tested on a road surface; According to the pre-acquired road load spectrum of the target electric drive axle of the same model as the target electric drive axle in the road test, the test speed and torque are obtained; The target electric drive axle is driven according to the test speed and torque, and multi-directional loads are continuously applied to the axle housing of the target electric drive axle for a period of time based on the action excitation spectrum to obtain a real-time monitoring signal of the target electric drive axle; The reliability of the target electric drive axle is determined based on the real-time monitoring signal of the target electric drive axle.

[0006] Furthermore, the method for obtaining the road load spectrum of the electric drive axle of the same model as the target electric drive axle in the road test obtained in advance includes: On the reinforced road surface, the operating data of the vehicle equipped with the same type of electric drive axle as the target electric drive axle is collected; wherein the operating data includes: electric drive axle shaft head acceleration, electric drive axle housing stress, electric drive axle torque and electric drive axle speed data; Based on the operating data, a road load spectrum of the same model of the target electric drive axle is produced.

[0007] Further, the driving of the target electric drive axle according to the test speed and torque, and continuously applying multi-directional loads to the axle housing of the target electric drive axle for a period of time based on the action excitation spectrum, includes: Acquire a first response point output signal corresponding to an initial multi-directional load on the target electric drive axle; According to the road load spectrum, an output signal of a road load spectrum response point is obtained; Determining an excitation driving signal based on the first response point output signal and the road load spectrum response point output signal; The excitation drive signal is corrected based on the second response point output signal of the target electric drive bridge corresponding to the load and the road load spectrum response point output signal until the error between the second response point output signal and the test response point signal meets a preset threshold.

[0008] Furthermore, the step of determining the excitation drive signal based on the first response point output signal and the road load spectrum response point output signal includes: The frequency response function of the test bench is calculated by the following formula: ; in: represents the rig frequency response function corresponding to the initial multi-directional load; Indicates the output signal of the first response point; represents a white noise signal that causes the target electric drive axle to be subjected to an initial multi-directional load; The excitation drive signal is calculated by the following formula: ; in: represents an excitation driving signal that is not updated; represents the inverse matrix of the test bench frequency response function; Represents the output signal of the road load spectrum response point.

[0009] Furthermore, the excitation drive signal is updated based on the second response point output signal of the target electric drive bridge corresponding to the excitation drive signal and the road load spectrum response point output signal until the error between the updated second response point output signal corresponding to the updated excitation drive signal and the test response point signal meets a preset threshold, including: 1.1. Using the excitation drive signal to subject the target electric drive bridge to a load, and obtaining the second response point output signal of the target electric drive bridge corresponding to the excitation drive signal; 1.2. Compare the output signal of the second response point with the output signal of the road load spectrum response point, and update the excitation drive signal; 1.4. Using the updated excitation drive signal to subject the target electric drive bridge to a load, and obtaining a corresponding updated second response point output signal; 1.5. Compare the updated second response point output signal with the road load spectrum response point output signal to update the excitation drive signal; 1.6. Repeat steps 1.4 to 1.5 until the error between the updated second response point output signal and the test response point signal meets the preset threshold.

[0010] Furthermore, the comparing the second response point output signal with the road load spectrum response point output signal to update the excitation drive signal includes: Update the excitation drive signal by the following formula: ; ; in: represents an excitation driving signal that is not updated; Indicates n The excitation driving signal updated for the second time; Indicates n The updated correction signal; represents the inverse matrix of the test bench frequency response function; Indicates n The updated error signal, Depend on The corresponding second response point output signal is compared with the road load spectrum response point output signal; represents the compensation coefficient, .

[0011] Further, based on the real-time monitoring signal of the target electric drive axle, the reliability of the target electric drive axle is determined, including: Determine the monitoring signal waveform according to the real-time monitoring signal of the target electric drive bridge; If the amplitude of the monitoring signal waveform does not exceed the preset value, it is determined that the performance of the target electric drive axle is reliable, otherwise it is determined that the reliability of the performance of the target electric drive axle is questionable.

[0012] Another aspect of the present invention provides a reliability bench test device for an electric drive axle for a new energy vehicle, comprising: Bracket; A mounting seat, provided on the bracket, for mounting a target electric drive axle; A multi-directional load loading mechanism, distributed around the mounting base and arranged on the bracket, is used to apply a multi-directional load to the target electric drive axle housing; A dynamometer, connected to the target electric drive axle, for monitoring the speed and torque data of the target electric drive axle; A motor, connected to the target electric drive bridge, for driving the target electric drive bridge; Multiple acceleration sensors are respectively installed on the target electric drive axle shaft head and the axle housing to obtain real-time monitoring signals of the target electric drive axle; The controller is electrically connected to the multi-directional load loading mechanism, the dynamometer, the motor and the acceleration sensor.

[0013] Optionally, the multi-directional load loading mechanism includes a plurality of vertical dynamic actuators, a plurality of longitudinal dynamic actuators and a hydraulic oil source; The controllers are electrically connected to the vertical dynamic actuator and the longitudinal dynamic actuator; The hydraulic oil source is connected to the vertical dynamic actuator and the longitudinal dynamic actuator respectively; The housings of the vertical dynamic actuator and the longitudinal dynamic actuator are both connected to the bracket, and the action ends of the vertical dynamic actuator and the longitudinal dynamic actuator are both connected to the target electric drive axle.

[0014] Optionally, the target electric drive axle housing is also provided with a sound collecting device for collecting vibration radiation noise.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention obtains the test rotational speed and torque according to a pre-acquired road load spectrum of an electric drive axle of the same model as the target electric drive axle in a road test, drives the target electric drive axle by the test rotational speed and torque, applies multi-directional loads to the bridge shell of the target electric drive axle based on an action excitation spectrum generated based on the road load spectrum, determines the reliability of the target electric drive axle according to real-time monitoring signals during the test, simulates the actual working condition of the electric drive axle in operation under the actual comprehensive load, has the effects of short detection period and real reliability, and solves the problem that the reliability of the electric drive axle under extreme conditions cannot be truly detected by whole vehicle testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of a reliability bench test method for an electric drive axle for a new energy vehicle provided by an embodiment of the present invention; Figure 2 It is a schematic structural diagram of a reliability bench test device for an electric drive axle for a new energy vehicle provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of the installation of a bracket and a mounting seat in a reliability bench test device for an electric drive axle for a new energy vehicle provided by an embodiment of the present invention.

[0017] In the figure: 1, bracket; 2, mounting seat; 301, vertical dynamic actuator; 302, longitudinal dynamic actuator; 4, dynamometer; 5, electric drive axle; 6, bottom plate; 7, mounting hole; 8, first connecting hole; 9, second connecting hole. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0019] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. Example

[0020] like Figure 1 As shown, a reliability bench test method for an electric drive axle for a new energy vehicle includes: Based on the pre-acquired road load spectrum of the target electric drive axle of the same model in the road test, an action excitation spectrum is generated, wherein the method for acquiring the road load spectrum of the target electric drive axle of the same model in the road test includes: On the reinforced road surface, collect the operating data of the vehicle equipped with the same model of electric drive axle as the target electric drive axle; the operating data includes: electric drive axle shaft head acceleration, electric drive axle housing stress, electric drive axle torque and electric drive axle speed data; Based on the operating data, a road load spectrum of the same model of the target electric drive axle is produced.

[0021] According to the pre-acquired road load spectrum of the target electric drive axle of the same model as the target electric drive axle in the road test, the test speed and torque are obtained; The target electric drive axle is driven according to the test speed and torque, and multi-directional loads are continuously applied to the axle housing of the target electric drive axle for a period of time based on the action excitation spectrum. Specifically: Acquire a first response point output signal corresponding to an initial multi-directional load on the target electric drive axle; According to the road load spectrum, an output signal of a road load spectrum response point is obtained; Based on the first response point output signal and the road load spectrum response point output signal, an excitation driving signal is determined, including: The frequency response function of the test bench is calculated by the following formula: ; in: represents the rig frequency response function corresponding to the initial multi-directional load; Indicates the output signal of the first response point; represents a white noise signal that causes the target electric drive axle to be subjected to an initial multi-directional load; The excitation drive signal is calculated by the following formula: ; in: represents an excitation driving signal that is not updated; represents the inverse matrix of the test bench frequency response function; Represents the output signal of the road load spectrum response point; The excitation drive signal is corrected based on a second response point output signal of the target electric drive bridge corresponding to the excitation drive signal and a road load spectrum response point output signal until the error between the second response point output signal and the test response point signal meets a preset threshold, including: 1.1. Using the excitation drive signal to subject the target electric drive bridge to a load, and obtaining the second response point output signal of the target electric drive bridge corresponding to the excitation drive signal; 1.2. Compare the output signal of the second response point with the output signal of the road load spectrum response point, and update the excitation drive signal; 1.4. Using the updated excitation drive signal to subject the target electric drive bridge to a load, and obtaining a corresponding updated second response point output signal; 1.5. Compare the updated output signal of the second response point with the output signal of the road load spectrum response point, update the excitation drive signal, and update the excitation drive signal by the following formula: ; ; in: represents an excitation driving signal that is not updated; Indicates n The excitation driving signal updated for the second time; Indicates n The updated correction signal; represents the inverse matrix of the test bench frequency response function; Indicates n The updated error signal, Depend on The corresponding second response point output signal is compared with the road load spectrum response point output signal; represents the compensation coefficient, ; 1.6. Repeat steps 1.4 to 1.5 until the error between the updated second response point output signal and the test response point signal meets the preset threshold.

[0022] Obtain the real-time monitoring signal of the target electric drive axle, and determine the reliability of the target electric drive axle based on the real-time monitoring signal of the target electric drive axle, specifically: Determine the monitoring signal waveform according to the real-time monitoring signal of the target electric drive bridge; If the monitoring signal waveform is a time domain signal with a small fluctuation range, the target electric drive performance is reliable; If the monitoring signal waveform is an abnormal signal with a large fluctuation range, the reliability of the target electric drive performance is in doubt and requires further analysis and processing. Example

[0023] like Figure 2 As shown, a reliability bench test device for an electric drive bridge for a new energy vehicle comprises: a bracket 1, A mounting base 2, a multi-directional load loading mechanism, a dynamometer 4, a motor (not shown), a plurality of acceleration sensors (not shown) and a controller (not shown); wherein: the mounting base 2 is fixedly connected to the bottom of the bracket 1, such as Figure 3 As shown, in this example, a base plate 6 is further provided at the bottom of the bracket 1, and a plurality of mounting holes 7 are provided on the base plate 6. The bracket 1 and the mounting seat 2 are provided with a first connecting hole 8 and a second connecting hole 9 corresponding to the mounting holes. The installation position can be adjusted according to the size of the electric drive bridge 5 to be tested, thereby improving applicability.

[0024] The target electric drive axle 5 is mounted on the mounting seat 2; The motor is installed inside the target electric drive bridge 5 and is used to drive the target electric drive bridge 5; In this embodiment, there are two dynamometers 4, which are respectively connected to the two ends of the target electric drive axle 5 through universal joint couplings, and are used to monitor the speed and torque data of the target electric drive axle 5; A plurality of acceleration sensors are respectively installed on the shaft head and the bridge housing of the target electric drive bridge 5 to obtain real-time monitoring signals of the target electric drive bridge 5; In this example, the multi-directional load loading mechanism includes two vertical dynamic actuators 301, two longitudinal dynamic actuators 302 and a hydraulic oil source; the hydraulic oil source is connected to the two vertical dynamic actuators 301 and the two longitudinal dynamic actuators 302; Two vertical dynamic actuators 301 are arranged on the top of the target electric drive bridge 5, the housing of the vertical dynamic actuator 301 is connected to the bracket 1 through fasteners, and the action end is installed on the top of the target electric drive bridge 5; Two longitudinal dynamic actuators 302 are arranged on the front of the target electric drive axle 5, the housing of the longitudinal dynamic actuator 302 is connected to the bracket 1 through a fastener, and the action end is installed on the front of the target electric drive axle 5; The controller is electrically connected to the longitudinal dynamic actuator 302, the vertical dynamic actuator 301, the dynamometer 4, the motor and the acceleration sensor; The target electric drive axle 5 is also provided with a sound collecting device for collecting vibration radiation noise on the axle housing. The sound collecting device is electrically connected to the controller. In this embodiment, the sound collecting device is a microphone. The target electric drive axle 5 is mounted on the mounting seat 2; Inputting white noise signals to the vertical dynamic actuator 301 and the longitudinal dynamic actuator 302 through the controller, so that the vertical dynamic actuator 301 and the longitudinal dynamic actuator 302 apply initial multi-directional loads to the target electric drive axle 5; According to the road load spectrum of the same type of electric drive axle of the target electric drive axle 5 obtained in advance during the road test, the test speed and torque are obtained, and the target electric drive axle 5 is operated at the test speed and torque through the controller; The installation position of the acceleration sensor on the target electric drive bridge 5 is used as the response point, and the signal obtained by the acceleration sensor is used as the real-time monitoring signal. Through the acceleration sensor, the first response point output signal corresponding to the initial multi-directional load on the target electric drive bridge 5 is obtained; According to the road load spectrum, an output signal of a road load spectrum response point is obtained; Determining an excitation driving signal based on the first response point output signal and the road load spectrum response point output signal; The excitation drive signal is corrected based on the second response point output signal corresponding to the target electric drive bridge 5 subjected to the load and the road load spectrum response point output signal, until the error between the second response point output signal and the test response point signal meets a preset threshold; During the test, if the amplitude of the monitoring signal waveform does not exceed the preset value, the monitoring signal is a time domain signal with a small fluctuation range, and the performance of the target electric drive axle is determined to be reliable; If the amplitude of the monitoring signal waveform exceeds the preset value and shows a large fluctuation range, the monitoring signal is an abnormal signal, and the reliability of the target electric drive axle performance is questionable and needs further analysis and processing. Specifically: The vibration radiation noise sound pressure signal collected by the sound collection device during the test is also used as a monitoring signal, and the installation point of the sound collection device is used as a response point. NVH order analysis and processing are performed based on the monitoring signal, and combined with whether there are cracks near the response point on the target electric drive axle 5 to determine whether the problem ultimately comes from the electric drive axle 5 motor or shift gear.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0026] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A reliability bench test method for an electric drive axle for a new energy vehicle, characterized in that: include: Generate an action excitation spectrum based on a pre-acquired road load spectrum of an electric drive axle of the same model as the target electric drive axle in a road test; According to the pre-acquired road load spectrum of the target electric drive axle of the same model as the target electric drive axle in the road test, the test speed and torque are obtained; The target electric drive axle is driven according to the test speed and torque, and multi-directional loads are continuously applied to the axle housing of the target electric drive axle for a period of time based on the action excitation spectrum to obtain a real-time monitoring signal of the target electric drive axle; The reliability of the target electric drive axle is determined based on the real-time monitoring signal of the target electric drive axle.

2. The reliability bench test method for electric drive axles for new energy vehicles according to claim 1 is characterized in that: The method for obtaining the road load spectrum of the electric drive axle of the same model as the target electric drive axle in the road test obtained in advance comprises: On the reinforced road surface, the operating data of the vehicle equipped with the same type of electric drive axle as the target electric drive axle is collected; wherein the operating data includes: electric drive axle shaft head acceleration, electric drive axle housing stress, electric drive axle torque and electric drive axle speed data; Based on the operating data, a road load spectrum of the same model of the target electric drive axle is produced.

3. The reliability bench test method for electric drive axles for new energy vehicles according to claim 1 is characterized in that: The target electric drive axle is driven according to the test speed and torque, and a multi-directional load is continuously applied to the axle housing of the target electric drive axle for a period of time based on the action excitation spectrum, including: Acquire a first response point output signal corresponding to an initial multi-directional load on the target electric drive axle; According to the road load spectrum, an output signal of a road load spectrum response point is obtained; Determining an excitation driving signal based on the first response point output signal and the road load spectrum response point output signal; The excitation drive signal is corrected based on the second response point output signal of the target electric drive bridge corresponding to the load and the road load spectrum response point output signal until the error between the second response point output signal and the test response point signal meets a preset threshold.

4. The reliability bench test method for electric drive axles for new energy vehicles according to claim 3 is characterized in that: The step of determining the excitation drive signal based on the first response point output signal and the road load spectrum response point output signal comprises: The frequency response function of the test bench is calculated by the following formula: ； in: represents the rig frequency response function corresponding to the initial multi-directional load; Indicates the output signal of the first response point; represents a white noise signal that causes the target electric drive axle to be subjected to an initial multi-directional load; The excitation drive signal is calculated by the following formula: ； in: represents an excitation driving signal that is not updated; represents the inverse matrix of the test bench frequency response function; Represents the output signal of the road load spectrum response point.

5. The reliability bench test method for electric drive axles for new energy vehicles according to claim 3 is characterized in that: The method updates the excitation drive signal based on the second response point output signal of the target electric drive bridge corresponding to the excitation drive signal and the road load spectrum response point output signal until the error between the updated second response point output signal corresponding to the updated excitation drive signal and the test response point signal meets a preset threshold, including: 1.

1. Using the excitation drive signal to subject the target electric drive bridge to a load, and obtaining the second response point output signal of the target electric drive bridge corresponding to the excitation drive signal; 1.

2. Compare the output signal of the second response point with the output signal of the road load spectrum response point, and update the excitation drive signal; 1.

4. Using the updated excitation drive signal to subject the target electric drive bridge to a load, and obtaining a corresponding updated second response point output signal; 1.

5. Compare the updated second response point output signal with the road load spectrum response point output signal to update the excitation drive signal; 1.

6. Repeat steps 1.4 to 1.5 until the error between the updated second response point output signal and the test response point signal meets the preset threshold.

6. The reliability bench test method for electric drive axles for new energy vehicles according to claim 5 is characterized in that: The step of comparing the second response point output signal with the road load spectrum response point output signal to update the excitation drive signal includes: Update the excitation drive signal by the following formula: ； ； in: represents an excitation driving signal that is not updated; Indicates n The excitation driving signal updated, n>0; Indicates n The updated correction signal; represents the inverse matrix of the test bench frequency response function; Indicates n The updated error signal, Depend on The corresponding second response point output signal is compared with the road load spectrum response point output signal; represents the compensation coefficient, .

7. The reliability bench test method for electric drive axles for new energy vehicles according to claim 1 is characterized in that: Based on the real-time monitoring signal of the target electric drive axle, the reliability of the target electric drive axle is determined, including: Determine the monitoring signal waveform according to the real-time monitoring signal of the target electric drive bridge; If the amplitude of the monitoring signal waveform does not exceed the preset value, it is determined that the performance of the target electric drive axle is reliable, otherwise it is determined that the reliability of the performance of the target electric drive axle is questionable.

8. A reliability bench test device for electric drive axles for new energy vehicles, characterized in that: include: Bracket; A mounting seat, provided on the bracket, for mounting a target electric drive axle; A multi-directional load loading mechanism, distributed around the mounting base and arranged on the bracket, is used to apply a multi-directional load to the target electric drive axle housing; A dynamometer, connected to the target electric drive axle, for monitoring the speed and torque data of the target electric drive axle; A motor, connected to the target electric drive bridge, for driving the target electric drive bridge; Multiple acceleration sensors are respectively installed on the target electric drive axle shaft head and the axle housing to obtain real-time monitoring signals of the target electric drive axle; The controller is electrically connected to the multi-directional load loading mechanism, the dynamometer, the motor and the acceleration sensor.

9. The reliability bench test device for electric drive axle for new energy vehicles according to claim 8 is characterized in that: The multi-directional load loading mechanism includes a plurality of vertical dynamic actuators, a plurality of longitudinal dynamic actuators and a hydraulic oil source; The controllers are electrically connected to the vertical dynamic actuator and the longitudinal dynamic actuator; The hydraulic oil source is connected to the vertical dynamic actuator and the longitudinal dynamic actuator respectively; The housings of the vertical dynamic actuator and the longitudinal dynamic actuator are both connected to the bracket, and the action ends of the vertical dynamic actuator and the longitudinal dynamic actuator are both connected to the target electric drive axle.

10. The reliability bench test device for electric drive axles for new energy vehicles according to claim 9 is characterized in that: The target electric drive axle housing is also provided with a sound collecting device for collecting vibration radiation noise.

Images