Evaluation method and system of slip joint, storage medium and equipment

Abstract

The invention discloses a slip joint evaluation method and system, a storage medium and equipment. The method comprises the following steps: acquiring a first center point coordinate of an electric drive end slip joint of a vehicle in a static state and a second center point coordinate of a wheel end fixed joint; acquiring torque on a driving shaft in an acceleration state of the vehicle and vertical displacement variation between central points of upper and lower mounting seats of a suspension spring; according to the torque and the first center point coordinate, the first displacement variation of the electric drive end slip joint is determined; according to the first center point coordinate, the vertical displacement variable quantity and the first displacement variable quantity, determining a new center point coordinate of the electric drive end slip joint; determining a dynamic included angle between the driving shaft and the electric drive torque output shaft according to the second center point coordinate, the new center point coordinate and the axis of the electric drive torque output shaft; and according to the dynamic included angle and a preset included angle value, determining whether the electric drive end slip joint is qualified. According to the invention, the qualification of the slip joint is detected through the dynamic included angle, so that the purposes of optimizing vehicle noise and reducing vehicle vibration are achieved.

Description

Technical Field

[0001] The present invention relates to the field of automobile transmission systems, and in particular to a slip joint evaluation method, system, storage medium and equipment. Background Art

[0002] The slip joint is a core component of power transmission in electric vehicles, and its performance directly affects the vehicle's dynamics, NVH performance, and transmission system reliability. If there are design or manufacturing defects in the slip joint during the development stage, it will lead to abnormal vibration, abnormal noise, reduced transmission efficiency, and other problems in mass-produced vehicles, and even cause safety hazards such as power interruption. Therefore, it is necessary to conduct qualified performance testing of the slip joint during the development stage. The existing technology usually fixes the slip joint on a test bench and directly applies a single-direction torque or axial thrust to it to measure the sliding resistance of the slip joint, so as to determine whether the slip joint has passed the test. However, this technology cannot capture abnormal responses of the slip joint under dynamic conditions. Summary of the Invention

[0003] In view of this, the present invention provides a slip joint evaluation method, system, storage medium and device, which aim to detect the eligibility of the slip joint in a vehicle motion state through dynamic angle, so as to optimize vehicle noise and reduce vehicle vibration.

[0004] To achieve the above objectives, a first aspect of an embodiment of the present application provides a method for evaluating a slip joint, the method comprising: Obtain the coordinates of the first center point of the electric drive end sliding joint and the second center point of the wheel end fixed joint when the vehicle is stationary; Obtain the torque on the drive shaft and the vertical displacement change between the center points of the upper and lower mounting bases of the suspension spring when the vehicle is accelerating; Determining a first displacement change of the center point coordinate of the electric drive end sliding joint according to the torque and the first center point coordinate; Determining new center point coordinates of the electric drive end sliding joint according to the first center point coordinates, the vertical displacement change, and the first displacement change; determining a dynamic angle between the drive shaft and the electric drive torque output shaft according to the second center point coordinates, the new center point coordinates, and the axis of the electric drive torque output shaft; Whether the electric drive end sliding joint is qualified is determined based on the dynamic angle and the preset angle value.

[0005] Optionally, determining a change in vertical displacement between center points of upper and lower mounting seats of a suspension spring includes: Obtain the coordinates of the center point of the suspension spring mounting seat in a stationary state and the coordinates of the center point of the suspension spring mounting seat in an accelerated state; Obtain the coordinates of the center point of the suspension spring lower mounting seat in a stationary state and the coordinates of the center point of the acceleration point in an accelerated state; By performing displacement calculation on the coordinates of the static center point and the acceleration center point of the upper mounting seat of the suspension spring, as well as the coordinates of the static center point and the acceleration center point of the lower mounting seat of the suspension spring, the vertical displacement change between the center points of the upper and lower mounting seats of the suspension spring is determined.

[0006] Optionally, determining a first displacement change of the center point coordinate of the electric drive end sliding joint according to the torque and the first center point coordinate includes: Applying the torque generated by the drive shaft to a pre-established multi-body dynamics model to cause displacement of the slip joint at the electric drive end of the drive shaft in the multi-body dynamics model; When the sliding joint at the electric drive end of the drive shaft is displaced, obtaining the coordinates of the third center point of the displaced sliding joint at the electric drive end; According to the first center point coordinates and the third center point coordinates, a first displacement change of the center point coordinates of the electric drive end sliding joint is determined.

[0007] Optionally, determining a dynamic angle between the drive shaft and the electric drive torque output shaft according to the second center point coordinate, the new center point coordinate, and the axis of the electric drive torque output shaft includes: Determine the axis vector of the drive shaft according to the coordinates of the second center point and the new center point coordinates of the electric drive end sliding joint; The axis vector of the drive shaft and the axis vector of the electric drive torque output shaft are calculated using a spatial angle algorithm to obtain the dynamic angle between the drive shaft and the electric drive torque output shaft.

[0008] Optionally, determining whether the electric drive end sliding joint is qualified according to the dynamic angle and the preset angle value includes: Comparing the dynamic angle with the preset angle value to obtain a comparison result; If the comparison result shows that the dynamic angle is smaller than the preset angle value, it is determined that the electric drive end sliding joint is qualified; When the comparison result shows that the dynamic angle is greater than or equal to the preset angle value, it is determined that the electric drive end sliding joint is unqualified and the electric drive end sliding joint is not compatible with the vehicle.

[0009] Optionally, the determination of the torque includes: Obtain the vehicle's motor output torque and the gear ratio of the reducer; The torque on the drive shaft is obtained according to the output torque of the motor and the transmission ratio of the reducer.

[0010] Optionally, the multi-body dynamics model is a dynamics model including suspension position, stiffness, electric drive mass and moment of inertia.

[0011] A second aspect of an embodiment of the present application provides a sliding joint evaluation system, the system comprising: A center point coordinate first determination module is used to obtain the first center point coordinate of the electric drive end sliding joint and the second center point coordinate of the wheel end fixed joint when the vehicle is in a stationary state; a first displacement change determination module, configured to obtain the torque on the drive shaft and the vertical displacement change between the center points of the upper and lower mounting seats of the suspension spring when the vehicle is accelerating; a second displacement change determination module, configured to determine a first displacement change of the center point coordinates of the electric drive end sliding joint according to the torque and the first center point coordinates; a second center point coordinate determination module, configured to determine a new center point coordinate of the electric drive end sliding joint according to the first center point coordinate, the vertical displacement change, and the first displacement change; a dynamic angle determination module, configured to determine a dynamic angle between the drive shaft and the electric drive torque output shaft based on the second center point coordinates, the new center point coordinates, and the axis of the electric drive torque output shaft; The slip joint judgment module is used to determine whether the slip joint at the electric drive end is qualified based on the dynamic angle and the preset angle value.

[0012] A third aspect of an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps in any one of the slip joint evaluation methods described in the first aspect are implemented.

[0013] A fourth aspect of an embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of any of the slip joint evaluation methods described in the first aspect are implemented.

[0014] A slip joint evaluation method provided in the present application includes: obtaining the first center point coordinates of the slip joint at the electric drive end and the second center point coordinates of the fixed joint at the wheel end when the vehicle is stationary; obtaining the torque on the drive shaft and the vertical displacement change between the center points of the upper and lower mounting seats of the suspension spring when the vehicle is accelerated; determining the first displacement change of the center point coordinates of the slip joint at the electric drive end based on the torque and the first center point coordinates; determining the new center point coordinates of the slip joint at the electric drive end based on the first center point coordinates, the vertical displacement change and the first displacement change; determining the dynamic angle between the drive shaft and the electric drive torque output shaft based on the second center point coordinates, the new center point coordinates and the axis of the electric drive torque output shaft; and determining whether the slip joint at the electric drive end is qualified based on the dynamic angle and a preset angle value.

[0015] By obtaining the coordinates of the first center point of the electric drive-end slip joint when the vehicle is stationary, and then obtaining the displacement change between the center points of the upper and lower suspension spring mountings and the displacement change of the electric drive-end slip joint during acceleration (i.e., the vertical displacement change and the first displacement change), the new center point coordinates of the electric drive-end slip joint are determined. Based on these new center point coordinates, the coordinates of the second center point of the wheel-end fixed joint, and the axis of the electric drive torque output shaft, the dynamic angle between the drive shaft and the electric drive torque output shaft can be accurately determined. This dynamic angle is used to evaluate the dynamic performance of the electric drive-end slip joint, allowing only qualified slip joints to enter the assembly process, ensuring geometric compatibility and dynamic compatibility between the installed drive-end slip joint and the vehicle's driveline. Unqualified slip joints are intercepted and replaced to prevent abnormal vehicle vibration or friction noise caused by transmission imbalance after installation. The slip joint evaluation method of the present application ensures that the type of drive-end slip joint loaded on the vehicle is suitable for the type of vehicle loaded, and also avoids vibration and abnormal noise caused by unqualified drive-end slip joint, thereby ensuring the safety performance and comfort of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a step diagram of a slip joint evaluation method proposed in one embodiment of the present application; Figure 2 This is a schematic diagram of a dynamic angle provided by an embodiment of the present application; Figure 3 This is a schematic diagram of an electric drive output shaft flip provided by an embodiment of the present application; Figure 4 Schematic diagram of a sliding joint evaluation system provided in one embodiment of the present application. DETAILED DESCRIPTION

[0017] The following describes the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the various details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0018] In the prior art, a slip joint detection device is usually used to sample and test the key geometric parameters of the slip joint, but this technology only detects static geometric dimensions and cannot evaluate the performance degradation of the slip joint under dynamic loads (such as high-frequency torsion, impact vibration). In addition, the present application takes into account that in the actual working conditions of vehicle driving, the important role of the slip joint is to compensate for the changes in the length and angle of the drive shaft caused by the suspension movement, and the displacement suspension bounce (vertical displacement) and torque reaction (axial tension / compression) of the slip joint are jointly driven, and the coupling of the two affects the motion trajectory of the slip joint. Therefore, the present application simulates the changes that occur in the slip joint in dynamic working conditions through suspension bounce and torque action to determine whether the slip joint is qualified. In view of this, the present application determines the qualification of the electric drive end slip joint by obtaining the dynamic angle between the drive shaft and the electric drive torque output shaft when the vehicle is in motion, so as to avoid the problem of dynamic performance blind spots in slip joint detection in the prior art.

[0019] refer to Figure 1 , Figure 1 1 is a step diagram of a slip joint evaluation method proposed in one embodiment of the present application, the method comprising the following steps: S11: Obtain the coordinates of the first center point of the electric drive end sliding joint and the coordinates of the second center point of the wheel end fixed joint when the vehicle is in a stationary state.

[0020] In this embodiment, the electric drive end slip joint refers to the sliding part of the constant velocity joint on the vehicle's drive shaft. Its core function is to transmit torque and adapt to the axial displacement and angular changes caused by suspension movement. The drive shaft is connected to the vehicle's electric drive torque output shaft through the electric drive end slip joint. The other end of the drive shaft is the wheel end fixed joint, which connects the drive shaft to the wheel. Figure 2 As shown, this embodiment also provides a dynamic angle schematic diagram. Figure 2In this embodiment, the drive shaft is provided with an electric drive end slip joint and a wheel end fixed joint at each end. To more accurately determine the displacement change of the drive shaft during vehicle acceleration, this embodiment measures the coordinates of the center point of the electric drive end slip joint of the drive shaft when the vehicle is stationary, obtaining the corresponding first center point coordinates. The coordinates of the center point of the wheel end fixed joint of the drive shaft are also measured, obtaining the corresponding second center point coordinates.

[0021] S12: Obtain the torque on the drive shaft in the vehicle acceleration state and the vertical displacement change between the center points of the upper and lower mounting seats of the suspension spring.

[0022] The vehicle's motor generates torque, which is then transmitted to the electric drive torque output shaft through the drive shaft. Under the action of the torque, the electric drive torque output shaft flips. Therefore, this embodiment can obtain the flipping condition of the electric drive torque output shaft by measuring the torque on the drive shaft when the vehicle is accelerated.

[0023] When a vehicle accelerates, the center points of the upper and lower mounting bases of the suspension springs also move up and down. Because the suspension springs are connected to the drive shaft, this movement also causes the drive shaft to move. Therefore, this embodiment also measures the coordinates of the center points of the upper and lower mounting bases of the suspension springs to determine the change in vertical displacement between the center points of the upper and lower mounting bases after the vehicle transitions from a stationary state to a moving state. This vertical displacement change is also the change in displacement of the drive shaft.

[0024] S13: Determine a first displacement change of the center point coordinate of the electric drive end sliding joint according to the torque and the first center point coordinate.

[0025] The torque acting on the electric drive torque output shaft causes it to flip, which in turn causes the electric drive end slip joint between the electric drive torque output shaft and the drive shaft to shift. By obtaining the coordinates of the electric drive end slip joint after displacement due to torque, as well as the coordinates of the first center point of the electric drive end slip joint when the vehicle is stationary, the first displacement change of the coordinates of the electric drive end slip joint center point can be obtained.

[0026] S14: Determine the new center point coordinates of the electric drive end sliding joint according to the first center point coordinates, the vertical displacement change and the first displacement change.

[0027] In this embodiment, the first center point coordinates represent the coordinates of the electric drive-side sliding joint before it is displaced by vehicle acceleration. The vertical displacement change and the first displacement change obtained through the above steps represent the displacement change of the electric drive-side sliding joint due to vehicle acceleration. This is because the suspension spring is connected to the drive shaft. If the suspension spring is displaced, the drive shaft must also be displaced to maintain the connection. Furthermore, because the wheel-end fixed joint on the drive shaft is fixed, the displacement change of the drive shaft is ultimately reflected by the displacement change of the electric drive-side sliding joint. By adding the vertical displacement change and the first displacement change to the first center point coordinates, the new center point coordinates of the electric drive-side sliding joint after the displacement change can be obtained.

[0028] S15: Determine a dynamic angle between the drive shaft and the electric drive torque output shaft according to the second center point coordinates, the new center point coordinates, and the axis of the electric drive torque output shaft.

[0029] The axis vector of the drive shaft when the vehicle is accelerating can be obtained by the coordinates of the second center point of the fixed joint at the wheel end of the drive shaft and the new center point coordinates of the sliding joint at the electric drive end. This axis vector reflects the position of the drive shaft in space. Then, the axis vector reflecting the spatial position of the electric drive torque output shaft is determined based on the axis of the electric drive torque output shaft. The dynamic angle between the drive shaft and the electric drive torque output shaft is determined by the output shaft axis vector and the electric drive torque output shaft axis vector, as shown in the figure. Figure 2 The angle shown in .

[0030] S16: Determine whether the electric drive end sliding joint is qualified according to the dynamic angle and the preset angle value.

[0031] Since the larger the dynamic angle, the more pronounced the vibration experienced by the vehicle, if the vehicle vibrates too violently, power transmission may be interrupted in severe cases. Therefore, the electric drive end slip joint needs to be replaced to restore its angle compensation capability and prevent vibration from worsening, which could lead to mechanical failure. To this end, this embodiment provides a preset angle value. This preset angle value is used to determine whether the dynamic angle between the drive shaft and the electric drive torque output shaft is too large, posing a threat to the vehicle's safe driving. Furthermore, the vehicle's current electric drive end slip joint is determined to be qualified. If qualified, the electric drive end slip joint is confirmed to be suitable for the vehicle model and the assessment is passed. If unqualified, the assessment is considered to have failed, and the vehicle's current drive end slip joint is considered to be prone to causing noise and abnormal vibration.

[0032] This application assembles various types of electric drive end sliding joints to vehicles of corresponding models, and evaluates the electric drive end sliding joints by obtaining the dynamic angle between the drive shaft and the electric drive torque output shaft when the vehicle accelerates. If the evaluation passes, it is considered that the type of drive end sliding joint currently assembled on the vehicle is compatible with the vehicle, and the electric drive end sliding joint can be normally assembled on the corresponding vehicle; if the evaluation fails, it indicates that the drive end sliding joint will cause abnormal vibration and noise to the vehicle, and the electric drive end sliding joint cannot be assembled on the vehicle. Through this evaluation method, the assembled electric drive end sliding joint is a type of sliding joint that can better adapt to the vehicle model, thereby ensuring the safety performance and comfort of the vehicle, and bringing users a safer and more comfortable driving experience.

[0033] In conjunction with the above embodiments, in one embodiment, the present invention further provides a method for evaluating a slip joint. In the method for evaluating a slip joint, determining the vertical displacement change between the center points of the upper and lower mounting seats of a suspension spring includes steps S21 to S23: S21: Obtain the coordinates of the stationary center point of the mounting seat on the suspension spring in a stationary state and the coordinates of the acceleration center point in an accelerated state.

[0034] S22: Obtain the coordinates of the stationary center point of the mounting seat under the suspension spring in a stationary state and the coordinates of the acceleration center point in an accelerated state.

[0035] S23: Determine a vertical displacement change between the center points of the upper and lower mounting seats of the suspension spring by performing displacement calculation on the coordinates of the stationary center point and the acceleration center point of the upper mounting seat of the suspension spring, as well as the coordinates of the stationary center point and the acceleration center point of the lower mounting seat of the suspension spring.

[0036] When the vehicle accelerates, the suspension spring undergoes spring compression due to the action of torque, which is specifically manifested as a decrease in the distance between the upper and lower mounting seats. When the suspension spring undergoes displacement changes, the drive shaft connected to the suspension spring also undergoes corresponding displacement changes to adapt to the displacement change. Therefore, in this embodiment, in order to determine the displacement change of the drive shaft caused by the displacement change of the suspension spring, the displacement change of the suspension spring is calculated.

[0037] Specifically, the center coordinates of the upper suspension spring mounting seat when the vehicle is stationary are measured to obtain the stationary center coordinates A1 (x1, y1, z1). The center coordinates of the upper suspension spring mounting seat when the vehicle is accelerated are then measured to obtain the accelerated center coordinates A2 (x2, y2, z2). The center coordinates of the lower suspension spring mounting seat when the vehicle is stationary are measured to obtain the stationary center coordinates B1 (x3, y3, z3). The center coordinates of the lower suspension spring mounting seat when the vehicle is accelerated are then measured to obtain the accelerated center coordinates B2 (x4, y4, z4). Based on the static center coordinates A1 (x1, y1, z1) and the acceleration center coordinates A2 (x2, y2, z2) of the upper suspension spring mount, the change in center displacement (dAx, dAy, dAz) of the upper suspension spring mount under accelerated conditions compared to the vehicle's static state is determined. This is the difference between the static center coordinates A1 (x1, y1, z1) and the acceleration center coordinates A2 (x2, y2, z2) of the upper suspension spring mount. Based on the static center coordinates B1 (x3, y3, z3) and the acceleration center coordinates B2 (x4, y4, z4) of the lower suspension spring mount, the change in center displacement (dBx, dBy, dBz) of the lower suspension spring mount under accelerated conditions compared to the vehicle's static state is determined. This is the difference between the static center coordinates B1 (x3, y3, z3) and the acceleration center coordinates B2 (x4, y4, z4) of the lower suspension spring mount. Then, based on the difference between the center point displacement changes of the upper mounting seat of the suspension spring (dAx, dAy, dAz) and the center point displacement changes of the lower mounting seat of the suspension spring (dBx, dBy, dBz), the vertical displacement change between the center points of the upper and lower mounting seats of the suspension spring is determined.

[0038] In addition, if the spring is a coil spring, the vertical displacement change can be measured by a wire displacement sensor, etc. If it is an air spring, the spring height change signal can be directly read through the vehicle CAN signal to obtain the vertical displacement change.

[0039] In combination with the above embodiments, in one embodiment, an embodiment of the present invention further provides a method for evaluating a sliding joint. In the method for evaluating a sliding joint, determining a first displacement change of the center point coordinate of the sliding joint at the electric drive end based on the torque and the first center point coordinate includes steps S31 to S33: S31: applying the torque to a pre-established multi-body dynamics model, so as to cause displacement of the slip joint at the electric drive end of the drive shaft in the multi-body dynamics model.

[0040] S32: When the sliding joint at the electric drive end of the drive shaft is displaced, the coordinates of the third center point of the displaced sliding joint at the electric drive end are obtained.

[0041] S33: Determine a first displacement change of the center point coordinate of the electric drive end sliding joint according to the first center point coordinate and the third center point coordinate.

[0042] Since the torque flip of the electric drive torque output shaft will cause a sudden change in the force state of the drive shaft, thereby affecting the displacement of the electric drive end slip joint, and because the drive shaft is dynamically coupled with components such as the motor, wheels, and suspension, the torque change will be transmitted to the slip joint through paths such as suspension geometry, bearing clearance, and spline friction, and simple static analysis cannot capture dynamic inertia forces, it is necessary to construct a multi-body dynamics model to simulate the dynamic interaction between multiple components and thereby determine the displacement change of the electric drive end slip joint of the drive shaft. Specifically, a multi-body dynamics model involving the electric drive torque output shaft is established, and torque simulation is applied to the multi-body dynamics model, causing the electric drive torque output shaft in the model to flip, thereby causing the electric drive slip joint connected to the electric drive torque output shaft to undergo a displacement change, such as Figure 3 As shown, this embodiment provides a schematic diagram of the flipping of the electric drive output shaft. When the electric drive end sliding joint of the drive shaft undergoes a displacement change, the third center point coordinates of the electric drive end sliding joint after the displacement change are measured and obtained. Since the displacement coordinates of the electric drive end sliding joint in the initial state are the first center point coordinates, the first displacement change of the electric drive end sliding joint center point coordinate caused by the flipping of the electric drive torque output shaft can be obtained based on the third center point coordinates after the displacement and the first center point coordinates before the displacement.

[0043] In conjunction with the above embodiments, in one embodiment, the present invention further provides a method for evaluating a slip joint. In this method, determining the dynamic angle between the drive shaft and the electric drive torque output shaft based on the second center point coordinates, the new center point coordinates, and the axis of the electric drive torque output shaft includes steps S41 to S42: S41: Determine the axis vector of the drive shaft according to the coordinates of the second center point and the new center point coordinates of the electric drive end sliding joint.

[0044] S42: Calculate the axis vector of the drive shaft and the axis vector of the electric drive torque output shaft using a spatial angle algorithm to obtain a dynamic angle between the drive shaft and the electric drive torque output shaft.

[0045] In this embodiment, the new center coordinates of the electric drive-end slip joint represent the position of the electric drive-end slip joint when the vehicle is accelerating, and the second center coordinates represent the position of the fixed joint at the wheel end of the drive shaft. The axis vector of the drive shaft can be determined based on the new center coordinates of the electric drive-end slip joint and the second center coordinates of the fixed joint at the wheel end of the drive shaft. For example, if the new center coordinates of the electric drive-end slip joint on the drive shaft are (x5, y5, z5) and the second center coordinates of the fixed joint at the wheel end of the drive shaft are (x6, y6, z6), then the axis vector of the drive shaft is (x5-x6, y5-y6, z5-z6).

[0046] The axis of the electric drive torque output shaft is parallel to the front and rear wheels of the vehicle, and the vector of the electric drive torque output shaft axis can be directly measured, or the axis of the electric drive torque output shaft can be directly set on the x-axis in the three-dimensional coordinate system, and based on this, the center point coordinates of the slip joint at the electric drive end of the drive shaft and the center point coordinates of the fixed joint at the wheel end of the drive shaft are measured. The vector of the electric drive torque output shaft axis and the axis vector of the drive shaft are substituted into the spatial angle algorithm for calculation to obtain the dynamic angle between the drive shaft and the electric drive torque output shaft. The expression of the spatial angle algorithm is:

[0047] in, is the dynamic angle between the drive shaft and the electric drive torque output shaft, is the axis vector of the driving shaft, is the axis modulus length of the drive shaft, is the vector of the electric drive torque output shaft axis, is the module length of the electric drive torque output shaft axis.

[0048] In combination with the above embodiments, in one embodiment, the present invention further provides a method for evaluating a sliding joint. In the method for evaluating a sliding joint, determining whether the sliding joint at the electric drive end is qualified based on the dynamic angle and the preset angle value includes steps S51 to S53: S51: Compare the dynamic angle with the preset angle value to obtain a comparison result.

[0049] S52: When the comparison result shows that the dynamic angle is smaller than the preset angle value, it is determined that the electric drive end sliding joint is qualified.

[0050] S53: When the comparison result shows that the dynamic angle is greater than or equal to the preset angle value, it is determined that the electric drive end sliding joint is unqualified and the electric drive end sliding joint is not compatible with the vehicle.

[0051] In order to determine whether the electric drive end slip joint currently assembled on the vehicle is suitable for the vehicle, this embodiment is also provided with a preset angle value. Specifically, the dynamic angle is compared with the preset angle value to obtain a corresponding comparison result, and based on the comparison result, it is determined whether the current electric drive end slip joint has passed the inspection and is suitable for the vehicle. In the case where the comparison result is that the dynamic angle is less than the preset angle value, it is determined that the current electric drive end slip joint will not cause the vehicle to generate large vibration and noise, so the evaluation result of the electric drive end slip joint is determined to be qualified and can be used normally. In the case where the comparison result is that the dynamic angle is greater than or equal to the preset angle value, it is determined that the current electric drive end slip joint will cause the vehicle to generate large vibration and noise, thereby causing a greater impact on the safe driving of the vehicle, so the evaluation result of the electric drive end slip joint is determined to be unqualified, and the current electric drive end slip joint is not suitable for the vehicle.

[0052] In combination with the above embodiments, in one embodiment, the present invention further provides a method for evaluating a slip joint. In the method for evaluating a slip joint, determining the torque includes steps S61 to S62: S61: Obtaining the motor output torque of the vehicle and the transmission ratio of the reducer; S62: Obtain the torque on the drive shaft according to the motor output torque and the transmission ratio of the reducer.

[0053] This embodiment also provides a method for determining the torque on the drive shaft, by determining the magnitude of the torque on the drive shaft, so as to facilitate the subsequent model simulation of the flipping of the electric drive torque output under the action of torque. Specifically, the output torque directly generated by the vehicle's motor and the speed ratio of the motor output shaft to the drive shaft are obtained. This ratio is the transmission ratio of the reducer, wherein the transmission ratio reflects the torque amplification factor. This is because the torque output by the motor is small and cannot directly drive the wheels, so it is necessary to obtain the torque on the drive shaft based on the output torque and the transmission ratio used to amplify the torque. The torque on the drive shaft acts on the wheels to rotate the wheels, and also acts on the connected electric drive torque output shaft to flip the electric drive torque output shaft.

[0054] In combination with the above embodiments, in one implementation, the present invention further provides a sliding joint evaluation method, wherein the multi-body dynamics model is a dynamics model including suspension position, stiffness, electric drive mass, and rotational inertia.

[0055] Specifically, the multi-body dynamics model includes the entire vehicle powertrain, of which the electric drive torque output shaft is a part. Figure 3This is the part of the electric drive torque output shaft. The powertrain also includes the motor, reducer, suspension system, drive shaft, electric drive end slip joint, etc. When building a dynamic model, it is necessary to first determine the parameters of the suspension position, stiffness, electric drive mass and moment of inertia. Among them, the suspension position is the installation point of the powertrain on the vehicle body, such as Figure 3 The left, right, and rear mounting points also determine the "fulcrum" location for the electric drive torque output shaft to flip. Mounting stiffness, the degree of hardness or softness of the mounting system, determines the amount of deformation of the electric drive torque output shaft when subjected to torque. This is because a high-stiffness mounting system can effectively resist the reaction force generated by torque, reducing the displacement of the powertrain, thereby limiting the deformation of the electric drive torque output shaft and minimizing the flip amplitude of the electric drive torque output shaft. A low-stiffness mounting system allows for greater displacement, causing the electric drive torque output shaft to deform more due to unstable support, resulting in a larger flip amplitude. The electric drive mass is the mass of the powertrain, which also includes the mass of the electric drive output shaft. The greater the electric drive mass, the greater the inertial resistance to flipping of the electric drive torque output shaft, and the greater the torque required to drive the flip. The moment of inertia is the inertia of the powertrain, including the electric drive torque output shaft, rotating around the axis of rotation. The greater the moment of inertia, the greater the ability of the electric drive torque output shaft to resist flipping.

[0056] By first building a 3D model of the powertrain and mounting points in dynamics software such as ADAMS, the obtained mounting position, stiffness, electric drive mass, and moment of inertia are input into the model to create a multi-body dynamics model. Torque is then applied to the electric drive torque output shaft in the multi-body dynamics model to simulate dynamic behaviors such as shaft rollover and slip joint displacement.

[0057] Based on the same inventive concept, an embodiment of the present application provides an evaluation system for a sliding joint, referring to Figure 4 , Figure 4 4 is a schematic diagram of a sliding joint evaluation system 400 proposed in one embodiment of the present application, wherein the system includes a vehicle-mounted terminal and a vehicle body controller; The center point coordinate first determination module 401 is used to obtain the first center point coordinate of the electric drive end sliding joint and the second center point coordinate of the wheel end fixed joint when the vehicle is in a stationary state; a first displacement change determination module 402 for obtaining the torque on the drive shaft and the vertical displacement change between the center points of the upper and lower mounting bases of the suspension spring when the vehicle is accelerating; A second displacement change determination module 403 is configured to determine a first displacement change of the center point coordinates of the electric drive end sliding joint according to the torque and the first center point coordinates; A second center point coordinate determination module 404 is configured to determine a new center point coordinate of the electric drive end sliding joint based on the first center point coordinate, the vertical displacement change, and the first displacement change; a dynamic angle determination module 405 for determining a dynamic angle between the drive shaft and the electric drive torque output shaft based on the second center point coordinates, the new center point coordinates, and the axis of the electric drive torque output shaft; The slip joint judgment module 406 is used to determine whether the slip joint at the electric drive end is qualified according to the dynamic angle and the preset angle value.

[0058] Optionally, the displacement change first determining module 402 includes: A first suspension coordinate determination module is used to obtain the coordinates of the stationary center point of the mounting seat on the suspension spring in a stationary state and the coordinates of the acceleration center point in an accelerated state; A second suspension coordinate determination module is used to obtain the coordinates of the stationary center point of the mounting seat under the suspension spring in a stationary state and the coordinates of the acceleration center point in an accelerated state; The vertical displacement change determination module is used to determine the vertical displacement change between the center points of the upper and lower mounting seats of the suspension spring by performing displacement calculations on the coordinates of the stationary center point and the acceleration center point of the upper mounting seat of the suspension spring, as well as the coordinates of the stationary center point and the acceleration center point of the lower mounting seat of the suspension spring.

[0059] Optionally, the second displacement change determination module 403 includes: a torque simulation module, configured to apply the torque to a pre-established multi-body dynamics model so as to cause displacement of the slip joint at the electric drive end of the drive shaft in the multi-body dynamics model; A third center point coordinate determination module is used to obtain the coordinates of the third center point of the displaced electric drive end sliding joint when the electric drive end sliding joint of the drive shaft is displaced; The first displacement change determination module is used to determine the first displacement change of the center point coordinate of the electric drive end sliding joint according to the first center point coordinate and the third center point coordinate.

[0060] Optionally, the dynamic angle determination module 405 includes: a drive shaft axis vector determination module, configured to determine the drive shaft axis vector according to the coordinates of the second center point and the new center point coordinates of the electric drive end sliding joint; The dynamic angle determination submodule is used to calculate the axis vector of the drive shaft and the axis vector of the electric drive torque output shaft through a spatial angle algorithm to obtain the dynamic angle between the drive shaft and the electric drive torque output shaft.

[0061] Optionally, the slip joint determination module 406 includes: A first judgment module is used to compare the dynamic angle with the preset angle value to obtain a comparison result; A second judgment module is configured to determine that the electric drive end sliding joint is qualified if the comparison result shows that the dynamic angle is smaller than the preset angle value; The third judgment module is used to determine that the electric drive end sliding joint is unqualified and the electric drive end sliding joint is not compatible with the vehicle when the comparison result shows that the dynamic angle is greater than or equal to the preset angle value.

[0062] Optionally, the slip joint evaluation system further includes: a first torque determination module, configured to obtain the motor output torque of the vehicle and the transmission ratio of the reducer; The second torque determination module is used to obtain the torque on the drive shaft according to the output torque of the motor and the transmission ratio of the reducer.

[0063] Based on the same inventive concept, another embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps in the slip joint evaluation method as described in any of the above embodiments are implemented.

[0064] Based on the same inventive concept, another embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, it implements the steps of the slip joint evaluation method as described in any of the above embodiments.

[0065] This application obtains the displacement change of the electric drive end sliding joint of the drive shaft caused by the suspension displacement change and the flip of the electric drive torque output shaft when the vehicle is in motion, and obtains the center point coordinates of the electric drive end sliding joint when the vehicle is stationary, to determine the new center point coordinates of the electric drive end sliding joint after the vehicle accelerates. The driving end position when the vehicle accelerates is thereby obtained, and then based on the driving shaft axis vector and the electric drive torque output shaft axis vector, the dynamic angle between the driving shaft and the electric drive torque output shaft is accurately obtained. The electric drive end sliding joint under the vehicle's accelerated motion is evaluated by the dynamic angle to evaluate whether the electric drive end sliding joint is qualified under the vehicle's accelerated state and whether it is suitable for the current vehicle. The evaluation method provided by this application detects the dynamic performance of the electric drive end sliding joint, so that the electric drive end sliding joint assembled on the vehicle is more compatible with the vehicle, thereby avoiding abnormal vibration and noise caused by the unqualified assembled electric drive end sliding joint.

[0066] Those skilled in the art will appreciate that embodiments of the present invention may provide methods, devices, electronic devices, storage media, or computer program products. Therefore, embodiments of the present invention may take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0067] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0068] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

[0069] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0070] In addition, in the specification and claims, "and / or" represents at least one of the connected objects, and the character " / " generally indicates that the previous and subsequent related objects are in an "or" relationship.

[0071] The above is a detailed introduction to the evaluation method, system, storage medium and equipment for a slip joint provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for evaluating a slip joint, characterized in that: The method comprises: Obtain the coordinates of the first center point of the electric drive end sliding joint and the second center point of the wheel end fixed joint when the vehicle is stationary; Obtain the torque on the drive shaft and the vertical displacement change between the center points of the upper and lower mounting bases of the suspension spring when the vehicle is accelerating; Determining a first displacement change of the center point coordinate of the electric drive end sliding joint according to the torque and the first center point coordinate; Determining new center point coordinates of the electric drive end sliding joint according to the first center point coordinates, the vertical displacement change, and the first displacement change; determining a dynamic angle between the drive shaft and the electric drive torque output shaft according to the second center point coordinates, the new center point coordinates, and the axis of the electric drive torque output shaft; Whether the electric drive end sliding joint is qualified is determined based on the dynamic angle and the preset angle value.

2. The slip joint evaluation method according to claim 1, characterized in that: Determine the vertical displacement change between the center points of the upper and lower mounting bases of the suspension spring, including: Obtain the coordinates of the center point of the suspension spring mounting seat in a stationary state and the coordinates of the center point of the suspension spring mounting seat in an accelerated state; Obtain the coordinates of the center point of the suspension spring lower mounting seat in a stationary state and the coordinates of the center point of the acceleration point in an accelerated state; By performing displacement calculation on the coordinates of the static center point and the acceleration center point of the upper mounting seat of the suspension spring, as well as the coordinates of the static center point and the acceleration center point of the lower mounting seat of the suspension spring, the vertical displacement change between the center points of the upper and lower mounting seats of the suspension spring is determined.

3. The slip joint evaluation method according to claim 1, characterized in that: Determining a first displacement change of the center point coordinate of the electric drive end sliding joint according to the torque and the first center point coordinate includes: Applying the torque to a pre-established multi-body dynamics model to cause displacement of the slip joint at the electric drive end of the drive shaft in the multi-body dynamics model; When the sliding joint at the electric drive end of the drive shaft is displaced, obtaining the coordinates of the third center point of the displaced sliding joint at the electric drive end; According to the first center point coordinates and the third center point coordinates, a first displacement change of the center point coordinates of the electric drive end sliding joint is determined.

4. The slip joint evaluation method according to claim 1, characterized in that: Determining a dynamic angle between the drive shaft and the electric drive torque output shaft according to the second center point coordinate, the new center point coordinate, and the axis of the electric drive torque output shaft includes: Determine the axis vector of the drive shaft according to the coordinates of the second center point and the new center point coordinates of the electric drive end sliding joint; The axis vector of the drive shaft and the axis vector of the electric drive torque output shaft are calculated using a spatial angle algorithm to obtain the dynamic angle between the drive shaft and the electric drive torque output shaft.

5. The slip joint evaluation method according to claim 1, characterized in that: Determining whether the electric drive end sliding joint is qualified according to the dynamic angle and the preset angle value includes: Comparing the dynamic angle with the preset angle value to obtain a comparison result; If the comparison result shows that the dynamic angle is smaller than the preset angle value, it is determined that the electric drive end sliding joint is qualified; When the comparison result shows that the dynamic angle is greater than or equal to the preset angle value, it is determined that the electric drive end sliding joint is unqualified and the electric drive end sliding joint is not compatible with the vehicle.

6. The slip joint evaluation method according to claim 1, characterized in that: The determination of torque includes: Obtain the vehicle's motor output torque and the gear ratio of the reducer; The torque on the drive shaft is obtained according to the output torque of the motor and the transmission ratio of the reducer.

7. The slip joint evaluation method according to claim 3, characterized in that: The multi-body dynamics model is a dynamics model including suspension position, stiffness, electric drive mass and rotational inertia.

8. A sliding joint evaluation system, characterized in that: The system comprises: A center point coordinate first determination module is used to obtain the first center point coordinate of the electric drive end sliding joint and the second center point coordinate of the wheel end fixed joint when the vehicle is in a stationary state; a first displacement change determination module, configured to obtain the torque on the drive shaft and the vertical displacement change between the center points of the upper and lower mounting seats of the suspension spring when the vehicle is accelerating; a second displacement change determination module, configured to determine a first displacement change of the center point coordinates of the electric drive end sliding joint according to the torque and the first center point coordinates; a second center point coordinate determination module, configured to determine a new center point coordinate of the electric drive end sliding joint according to the first center point coordinate, the vertical displacement change, and the first displacement change; a dynamic angle determination module, configured to determine a dynamic angle between the drive shaft and the electric drive torque output shaft based on the second center point coordinates, the new center point coordinates, and the axis of the electric drive torque output shaft; The slip joint judgment module is used to determine whether the slip joint at the electric drive end is qualified based on the dynamic angle and the preset angle value.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the slip joint evaluation method according to any one of claims 1 to 7 are implemented.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the slip joint evaluation method according to any one of claims 1 to 7 are implemented.

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