Vehicle tire envelope design method and apparatus

Abstract

The application discloses a vehicle tire envelope design method, which tracks at least three reference points selected on the wheels of a sample vehicle in real time during movement of the sample vehicle under a preset driving condition, determines a movement track of a wheel center according to the movement track of the at least three reference points during movement of the sample vehicle under the preset driving condition, determines five-degree-of-freedom parameters of the wheel center according to the movement track of the wheel center, inputs the five-degree-of-freedom parameters of the wheel center into a five-degree-of-freedom parameterized point-line model built in advance, runs the five-degree-of-freedom parameterized point-line model, and obtains a tire envelope result. The tire envelope result is obtained by analyzing the movement state of the actual vehicle, realizes reverse mapping of the tire envelope, can significantly improve the precision of the tire envelope, greatly reduces the size of the tire envelope, and improves the space utilization. Accordingly, the application also provides a vehicle tire envelope design device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle design, and in particular to a vehicle tire envelope design method and device. BACKGROUND

[0002] The tire movement envelope is the space position occupied by the tire when the wheels jump and turn with the suspension under various driving conditions. Tire envelope analysis is mainly to obtain the tire envelope surface. The tire envelope surface determines the shape of the wheel cover and fender, and can check the motion interference of the wheels and the surrounding subsystems, and also affects the design changes of the subsystems, such as the transverse stabilizer and the frame; in the early design stage, the tire movement envelope also affects the wheel track and the minimum turning diameter of the vehicle architecture development parameters. Therefore, accurate analysis of the tire movement envelope has a certain effect and significance in the early development stage of the vehicle project.

[0003] The existing general tire envelope design method is to assemble each part of the suspension and add various kinematic pairs to make the model run, and to perform tire movement analysis according to the pre-set wheel center and steering stroke roof diagram to simulate the movement of the actual tire. Then, the tire envelope is generated according to the space swept by the tire, and finally the vehicle is designed and developed according to the tire envelope.

[0004] However, the applicant found in the implementation of the above process that the tire envelope method based on the modeling of the suspension system requires the design of dozens of parts and kinematic pairs in modeling, and the modeling process is complex and low in efficiency. In addition, the tire envelope obtained by using the above tire envelope design method has a large difference from the actual tire movement, and the precision is not high. In order to avoid the interference between the tire envelope and the surrounding parts, the tire envelope must be enlarged, and a larger safety gap must be reserved, which causes a great waste of space, compresses the space of the passenger compartment, and also limits the design space of the chassis, body and interior and exterior parts, which is not conducive to the improvement of the vehicle performance. SUMMARY

[0005] The vehicle tire envelope design method and device provided by the embodiments of the present application can effectively solve the problem of the large difference between the tire envelope generated by the tire envelope design method of the prior art and the actual tire movement and the low precision.

[0006] The vehicle tire envelope design method provided by the embodiments of the present application comprises:

[0007] tracking the movement trajectories of at least three reference points selected on the wheels of the sample vehicle in the movement process of the sample vehicle under the preset driving condition in real time;

[0008] determining the movement trajectory of the wheel center according to the movement trajectories of the at least three reference points in the movement process of the sample vehicle under the preset driving condition;

[0009] According to the motion trajectory of the wheel center, five-degree-of-freedom parameters of the wheel center are obtained;

[0010] The five-degree-of-freedom parameters of the wheel center are input into a pre-built five-degree-of-freedom parameterized point-line model, and the five-degree-of-freedom parameterized point-line model is run to obtain a tire envelope result.

[0011] Preferably, the real-time tracking of the motion trajectories of at least three reference points selected on the wheels of the sample vehicle during the movement of the sample vehicle under the preset driving condition specifically includes:

[0012] A first coordinate system is established based on the sample vehicle before movement, and three-dimensional coordinates of the at least three reference points in the first coordinate system before movement of the sample vehicle are obtained;

[0013] A second coordinate system that changes in real time with the movement of the sample vehicle is established based on the sample vehicle moving under the preset driving condition, and three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion time are obtained.

[0014] Preferably, the determination of the motion trajectory of the wheel center according to the motion trajectories of the at least three reference points during the movement of the sample vehicle under the preset driving condition specifically includes:

[0015] Three-dimensional coordinates of a wheel center reference position at a preset distance from the wheel center in the first coordinate system are obtained; wherein the wheel center reference position is located on the rotation axis of the wheel;

[0016] The three-dimensional coordinates of the wheel center in the first coordinate system are determined according to the three-dimensional coordinates of the wheel center reference position in the first coordinate system;

[0017] The three-dimensional coordinates of the wheel center reference position in the second coordinate system at each motion time are determined according to the three-dimensional coordinates of the wheel center reference position in the first coordinate system, the three-dimensional coordinates of the at least three reference points in the first coordinate system before movement of the sample vehicle, and the three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion time;

[0018] The three-dimensional coordinates of the wheel center in the second coordinate system at each motion time are determined according to the three-dimensional coordinates of the wheel center reference position in the second coordinate system at each motion time.

[0019] Preferably, the determination of the three-dimensional coordinates of the wheel center reference position in the second coordinate system at each motion time according to the three-dimensional coordinates of the wheel center reference position in the first coordinate system, the three-dimensional coordinates of the at least three reference points in the first coordinate system before movement of the sample vehicle, and the three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion time specifically includes:

[0020] For each motion moment, the following wheel center reference position determination operation is performed:

[0021] According to the three-dimensional coordinates of the at least three reference points in the first coordinate system before the sample vehicle moves and the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion moment, a translation vector of the at least three reference points on the X, Y and Z axes at the current motion moment is determined;

[0022] According to the translation vector of the at least three reference points on the X, Y and Z axes at the current motion moment, a translation vector corresponding to the current wheel center reference position is determined;

[0023] According to the three-dimensional coordinates of the at least three reference points in the first coordinate system before the sample vehicle moves and the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion moment, an anti-symmetric matrix corresponding to the current wheel center reference position is determined;

[0024] According to the anti-symmetric matrix corresponding to the current wheel center reference position, a rotation matrix corresponding to the current wheel center reference position is constructed;

[0025] According to the translation vector corresponding to the current wheel center reference position, the rotation matrix corresponding to the current wheel center reference position and the three-dimensional coordinates of the wheel center reference position in the first coordinate system, the three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion moment are determined.

[0026] Preferably, the anti-symmetric matrix corresponding to the current wheel center reference position is determined according to the three-dimensional coordinates of the at least three reference points in the first coordinate system before the sample vehicle moves and the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion moment, specifically comprising:

[0027] Select three reference points from the at least three reference points as operation reference points;

[0028] The anti-symmetric matrix corresponding to the current wheel center reference position is determined by the following formula:

[0029]

[0030]

[0031] Wherein, S is the anti-symmetric matrix corresponding to the current wheel center reference position, X Aij is the coordinate difference value of the operation reference point i and the operation reference point j on the X axis in the first coordinate system, Y Aij is the coordinate difference value of the operation reference point i and the operation reference point j on the Y axis in the first coordinate system, and Z Aijis a coordinate difference value of the operation reference point i and the operation reference point j on a Z-axis in the first coordinate system, X Bij is a coordinate difference value of the operation reference point i and the operation reference point j on an X-axis in the second coordinate system at a current motion moment, Y Bij is a coordinate difference value of the operation reference point i and the operation reference point j on a Y-axis in the second coordinate system at the current motion moment, Z Bij is a coordinate difference value of the operation reference point i and the operation reference point j on a Z-axis in the second coordinate system at the current motion moment;

[0032] The rotation matrix corresponding to the current wheel center reference position is constructed according to the antisymmetric matrix corresponding to the current wheel center reference position, and specifically includes:

[0033] The rotation matrix corresponding to the current wheel center reference position is constructed by the following formula:

[0034]

[0035] Wherein, R is the rotation matrix corresponding to the current wheel center reference position, and I is a unit matrix.

[0036] Preferably, the three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion moment are determined according to the translation vector corresponding to the current wheel center reference position, the rotation matrix corresponding to the current wheel center reference position and the three-dimensional coordinates of the wheel center reference position in the first coordinate system, and specifically include:

[0037] The three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion moment are calculated by the following formula:

[0038]

[0039] Wherein, is the three-dimensional coordinates of the wheel center reference position in the first coordinate system, is the translation vector corresponding to the current wheel center reference position, R is the rotation matrix corresponding to the current wheel center reference position, is the three-dimensional coordinates of the wheel center reference position in the second coordinate system.

[0040] Preferably, the five degrees of freedom parameters of the wheel center are obtained according to the motion trajectory of the wheel center, and specifically include:

[0041] According to the three-dimensional coordinates of the wheel center in the first coordinate system and the three-dimensional coordinates of the wheel center in the second coordinate system at each motion moment, the movement degrees of freedom of the wheel center along the X, Y and Z axes are determined;

[0042] The origins of the first coordinate system are coincided with the origins of the second coordinate system at each movement time respectively, and vector coordinates of the at least three reference points at each movement time are determined;

[0043] According to the vector coordinates of the at least three reference points at each movement time, the rotational freedom of the wheel center around the X and Z axis directions is determined;

[0044] The movement freedom of the wheel center along the X, Y and Z axis directions and the rotational freedom of the wheel center around the X and Z axis directions are taken as five freedom parameters of the wheel center.

[0045] Preferably, the first coordinate system is established based on the sample vehicle before movement, and three-dimensional coordinates of the at least three reference points in the first coordinate system before movement of the sample vehicle are obtained, and specifically includes:

[0046] The at least three reference points are tracked in real time by using a shooting device, the first coordinate system is established based on the sample vehicle before movement, and the three-dimensional coordinates of the at least three reference points in the first coordinate system before movement of the sample vehicle are obtained based on the shooting picture;

[0047] The second coordinate system which changes in real time with movement of the sample vehicle is established based on the sample vehicle moving in a preset driving condition, and three-dimensional coordinates of the at least three reference points in the second coordinate system at each movement time are obtained, and specifically includes:

[0048] The second coordinate system which changes in real time with movement of the sample vehicle is established based on the sample vehicle moving in a preset driving condition, and the three-dimensional coordinates of the at least three reference points in the second coordinate system at each movement time are obtained based on the shooting picture.

[0049] Preferably, the shooting device is a high-speed camera.

[0050] Correspondingly, the embodiment of the application also provides a vehicle tire envelope design device, which comprises:

[0051] A reference point movement trajectory tracking module is configured to track movement trajectories of at least three reference points selected on wheels of a sample vehicle in a process in which the sample vehicle moves in a preset driving condition in real time;

[0052] A wheel center movement trajectory determination module is configured to determine a movement trajectory of a wheel center according to the movement trajectories of the at least three reference points in the process in which the sample vehicle moves in the preset driving condition;

[0053] A wheel center five freedom parameter acquisition module is configured to obtain five freedom parameters of the wheel center according to the movement trajectory of the wheel center.

[0054] A tire envelope acquisition module is configured to input the five-degree-of-freedom parameters of the wheel center into a pre-built five-degree-of-freedom parameterized point-line model, and run the five-degree-of-freedom parameterized point-line model to obtain a tire envelope result.

[0055] Compared with the prior art, the vehicle tire envelope design method provided by the embodiment of the present application can track the motion trajectories of at least three reference points selected on the wheels of a sample vehicle in real time during the motion of the sample vehicle in a preset driving condition, determine the motion trajectory of the wheel center according to the motion trajectories of the at least three reference points during the motion of the sample vehicle in the preset driving condition, determine the five-degree-of-freedom parameters of the wheel center according to the motion trajectory of the wheel center, input the five-degree-of-freedom parameters of the wheel center into a pre-built five-degree-of-freedom parameterized point-line model, and run the five-degree-of-freedom parameterized point-line model to obtain a tire envelope result. The vehicle tire envelope design method provided by the embodiment of the present application can realize reverse mapping of a tire envelope by analyzing the motion state of a real vehicle, can significantly improve the accuracy of the tire envelope, can greatly reduce the size of the tire envelope under the premise of meeting the use requirements of customers, can improve the space utilization, can provide more space for a chassis, a vehicle body and a passenger compartment, and can reduce the gap between a tire and a wheel arch. Accordingly, the embodiment of the present application also provides a vehicle tire envelope design device. BRIEF DESCRIPTION OF DRAWINGS

[0056] Figure 1 is a flowchart of the vehicle tire envelope design method provided by the embodiment of the present application;

[0057] Figure 2 is a schematic diagram of the positions of the at least three reference points and the reference position of the wheel center in the vehicle tire envelope design method provided by the embodiment of the present application;

[0058] Figure 3 is a structural block diagram of the vehicle tire envelope design device provided by the embodiment of the present application. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0060] Reference is made to Figure 1 which is a flowchart of the vehicle tire envelope design method provided by the embodiment of the present application.

[0061] The vehicle tire envelope design method provided by the embodiment of the present application includes steps S1 to S4:

[0062] Step S1, tracking in real time the motion trajectory of at least three reference points selected on the wheels of the sample vehicle during the motion of the sample vehicle under a preset driving condition;

[0063] Step S2, determining the motion trajectory of the wheel center according to the motion trajectory of the at least three reference points during the motion of the sample vehicle under the preset driving condition;

[0064] Step S3, obtaining the five-degree-of-freedom parameters of the wheel center according to the motion trajectory of the wheel center;

[0065] Step S4, inputting the five-degree-of-freedom parameters of the wheel center into a pre-established five-degree-of-freedom parameterized point-line model, and running the five-degree-of-freedom parameterized point-line model to obtain the tire envelope result.

[0066] The vehicle tire envelope design method provided by the embodiment of the application tracks in real time the motion trajectory of at least three reference points selected on the wheels of the sample vehicle during the motion of the sample vehicle under a preset driving condition, determines the motion trajectory of the wheel center according to the motion trajectory of the at least three reference points during the motion of the sample vehicle under the preset driving condition, determines the five-degree-of-freedom parameters of the wheel center according to the motion trajectory of the wheel center, inputs the five-degree-of-freedom parameters of the wheel center into a pre-established five-degree-of-freedom parameterized point-line model, and runs the five-degree-of-freedom parameterized point-line model to obtain the tire envelope result. The method realizes reverse mapping of the tire envelope by analyzing the motion state of the actual vehicle, can significantly improve the accuracy of the tire envelope, greatly reduces the size of the tire envelope under the premise of meeting the use requirements of customers, improves the space utilization, provides more space for the chassis, the vehicle body and the passenger compartment, and reduces the gap between the tire and the wheel arch. In addition, the motion trajectory of the wheel center obtained by the embodiment of the application can also be used for feedback correction of the simulation analysis model to improve the accuracy of the tire envelope simulation analysis.

[0067] In an optional embodiment, the step S1 of tracking in real time the motion trajectory of at least three reference points selected on the wheels of the sample vehicle during the motion of the sample vehicle under a preset driving condition specifically comprises:

[0068] establishing a first coordinate system based on the sample vehicle before motion, and obtaining the three-dimensional coordinates of the at least three reference points in the first coordinate system before the motion of the sample vehicle;

[0069] establishing a second coordinate system that changes in real time with the motion of the sample vehicle based on the sample vehicle moving under a preset driving condition, and obtaining the three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion time.

[0070] In the embodiment of the present application, in order to obtain different motion states of the wheel relative to the vehicle body, at least three reference points are selected on the wheel of the sample vehicle, and the positions of the reference points on the wheel of the sample vehicle are located by establishing a coordinate system, so as to determine the position and angle change of the wheel center relative to the vehicle body during the movement of the sample vehicle in the preset driving condition. In some embodiments, the coordinate system can be established on the vehicle body, and the front-rear direction of the vehicle is defined as the X axis, the left-right direction of the vehicle is defined as the Y axis, and the up-down direction of the vehicle is defined as the Z axis. Since the spatial motion state of the sample vehicle changes during movement, the second coordinate system after movement changes in real time at each motion moment. It should be noted that each motion moment refers to each sampling moment, and in specific implementation, a sampling interval can be preset, and the coordinate positions of the at least three reference points are collected every preset sampling interval, and the motion change state of the wheel relative to the vehicle body is obtained through the coordinates of the at least three reference points.

[0071] In the embodiment of the present application, the preset driving condition can simulate the actual vehicle motion state, for example, the preset driving condition can be an experimental condition such as pit driving of the sample vehicle, so as to simulate the limit state of the wheel, and thus information such as the up-down limit position of the wheel can be obtained.

[0072] In an alternative embodiment, the wheel center motion trajectory is determined according to the motion trajectory of the at least three reference points during movement of the sample vehicle in the preset driving condition, and specifically includes:

[0073] The three-dimensional coordinates of the wheel center reference position in the first coordinate system are obtained, wherein the wheel center reference position is located on the rotation axis of the wheel;

[0074] The three-dimensional coordinates of the wheel center in the first coordinate system are determined according to the three-dimensional coordinates of the wheel center reference position in the first coordinate system;

[0075] The three-dimensional coordinates of the wheel center reference position in the second coordinate system at each motion moment are determined according to the three-dimensional coordinates of the wheel center reference position in the first coordinate system, the three-dimensional coordinates of the at least three reference points in the first coordinate system before movement of the sample vehicle, and the three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion moment;

[0076] The three-dimensional coordinates of the wheel center in the second coordinate system at each motion moment are determined according to the three-dimensional coordinates of the wheel center reference position in the second coordinate system at each motion moment.

[0077] In the embodiment of the present application, the position change of the sample vehicle wheel relative to the sample vehicle body is obtained through the position change of the at least three reference points. Since the structural parameters of the sample vehicle are known, the three-dimensional coordinates of any point on the wheel rigid body can be known on the basis of the position of the sample vehicle wheel relative to the sample vehicle body. Figure 2 The positions of the at least three reference points and the schematic diagram of the wheel center reference position are exemplarily given. In some embodiments, the at least three reference points are arranged on the wheel adapter, and the wheel center reference position C is arranged on a point of the side of the wheel adapter close to the tire. At this time, the preset value is equal to E+2 / W, wherein E is the offset distance representing the distance between the wheel adapter and the tire, and W is the tire width. Then, the three-dimensional coordinates of the wheel center at each motion time can be obtained by calculating the three-dimensional coordinates of the wheel center reference position at each motion time.

[0078] In an alternative embodiment, the determination of the three-dimensional coordinates of the wheel center reference position in the second coordinate system at each motion time according to the three-dimensional coordinates of the wheel center reference position in the first coordinate system, the three-dimensional coordinates of the at least three reference points in the first coordinate system before the sample vehicle moves, and the three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion time specifically comprises:

[0079] For each motion time, the following wheel center reference position determination operation is performed:

[0080] According to the three-dimensional coordinates of the at least three reference points in the first coordinate system before the sample vehicle moves and the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion time, the translation vectors of the at least three reference points on the X, Y, and Z axes at the current motion time are determined;

[0081] According to the translation vectors of the at least three reference points on the X, Y, and Z axes at the current motion time, the translation vector corresponding to the current wheel center reference position is determined;

[0082] According to the three-dimensional coordinates of the at least three reference points in the first coordinate system before the sample vehicle moves and the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion time, the skew-symmetric matrix corresponding to the current wheel center reference position is determined;

[0083] According to the skew-symmetric matrix corresponding to the current wheel center reference position, the rotation matrix corresponding to the current wheel center reference position is constructed;

[0084] According to the translation vector corresponding to the current wheel center reference position, the rotation matrix corresponding to the current wheel center reference position, and the three-dimensional coordinates of the wheel center reference position in the first coordinate system, the three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion moment are determined.

[0085] In the three-dimensional space, different coordinate systems can be transformed through the Euclidean transformation. Generally, the transformation between two coordinate systems consists of rotation and translation. In the embodiment of the present application, the coordinates of the wheel center reference position in the first coordinate system before the motion of the sample vehicle and in the second coordinate system at each motion moment are different. In order to obtain the position and attitude of the wheel center reference position during the motion, for the second coordinate system at each motion moment, the second coordinate system at each motion moment can be obtained by performing rotation transformation and translation transformation on the first coordinate system, so as to obtain the three-dimensional coordinates of the wheel center reference position at different motion moments.

[0086] For the translation transformation between the coordinate systems, in the embodiment of the present application, the translation vector before and after the change of any reference point can be obtained, and the translation vector is also the translation vector of the current wheel center reference position on the X, Y and Z axes. In addition, the coordinates of the vector from the origin of the first coordinate system to the origin of the second coordinate system at the current motion moment in the second coordinate system at the current motion moment can be obtained, and the translation vector, which is also the translation vector of the current wheel center reference position on the X, Y and Z axes, can be obtained.

[0087] For the rotation transformation in the coordinate system, the rotation relationship between the two coordinate systems can be obtained by obtaining the rotation matrix from the first coordinate system to the second coordinate system at the current motion moment. Therefore, the rotation matrix from the first coordinate system to the second coordinate system at the current motion moment needs to be obtained first, and the rotation matrix can be constructed by using the skew-symmetric matrix. Further, in an optional embodiment, the skew-symmetric matrix corresponding to the current wheel center reference position is determined according to the three-dimensional coordinates of the at least three reference points in the first coordinate system before the motion of the sample vehicle and the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion moment, specifically comprising:

[0088] Three reference points are selected from the at least three reference points as operation reference points; for example, the three operation reference points are a first operation reference point, a second operation reference point and a third operation reference point.

[0089] The skew-symmetric matrix corresponding to the current wheel center reference position is determined through formulas (1) and (2):

[0090]

[0091]

[0092] wherein S is an anti-symmetric matrix corresponding to the current wheel center reference position, X Aij is a coordinate difference value of the operation reference point i and the operation reference point j on the X axis in the first coordinate system, for example, X A12 is a coordinate difference value of the first operation reference point and the second operation reference point on the X axis in the first coordinate system; Y Aij is a coordinate difference value of the operation reference point i and the operation reference point j on the Y axis in the first coordinate system; Z Aij is a coordinate difference value of the operation reference point i and the operation reference point j on the Z axis in the first coordinate system; X Bij is a coordinate difference value of the operation reference point i and the operation reference point j on the X axis in the second coordinate system at the current motion moment, for example, X B12 is a coordinate difference value of the first operation reference point and the second operation reference point on the X axis in the second coordinate system; Y Bij is a coordinate difference value of the operation reference point i and the operation reference point j on the Y axis in the second coordinate system at the current motion moment, Z Bij is a coordinate difference value of the operation reference point i and the operation reference point j on the Z axis in the second coordinate system at the current motion moment;

[0093] The anti-symmetric matrix corresponding to the current wheel center reference position is constructed according to the anti-symmetric matrix corresponding to the current wheel center reference position, and specifically includes:

[0094] The rotation matrix corresponding to the current wheel center reference position is constructed through formula (3):

[0095]

[0096] wherein R is a rotation matrix corresponding to the current wheel center reference position, and I is a unit matrix.

[0097] In the embodiment of the application, a, b, and c are calculated through formula (2), and the anti-symmetric matrix S is determined according to a, b, c, and formula (1). In a specific implementation, when the rotation relationship and the translation relationship between the two coordinate systems are determined, the Euclidean transformation formula between the two coordinate systems can be determined, and the three-dimensional coordinates of the wheel center reference position in the second coordinate system at each motion moment are obtained from the Euclidean transformation formula between the two coordinate systems. Therefore, in an optional implementation, the three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion moment are determined according to the translation vector corresponding to the current wheel center reference position, the rotation matrix corresponding to the current wheel center reference position, and the three-dimensional coordinates of the wheel center reference position in the first coordinate system, and specifically include:

[0098] calculating the three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion time point through formula (4):

[0099]

[0100] wherein, is the three-dimensional coordinates of the wheel center reference position in the first coordinate system, is a translation vector corresponding to the current wheel center reference position, and R is a rotation matrix corresponding to the current wheel center reference position, is the three-dimensional coordinates of the wheel center reference position in the second coordinate system.

[0101] In the embodiment of the present application, the three-dimensional coordinates of the wheel center reference position at each motion time point are obtained based on the Euclidean transformation, and then the three-dimensional coordinates of the wheel center at each motion time point are obtained, so as to obtain the motion trajectory of the wheel center of the sample vehicle, so as to obtain the five-degree-of-freedom parameters of the wheel center of the sample vehicle based on the motion trajectory of the wheel center of the sample vehicle, and the tire motion envelope surface can be generated by inputting the five-degree-of-freedom parameters into the simulation model and running the simulation model.

[0102] In an alternative embodiment, the five-degree-of-freedom parameters of the wheel center are obtained according to the motion trajectory of the wheel center, specifically including:

[0103] determining the movement degrees of freedom of the wheel center along the X, Y and Z axis directions according to the three-dimensional coordinates of the wheel center in the first coordinate system and the three-dimensional coordinates of the wheel center in the second coordinate system at each motion time point;

[0104] coinciding the origins of the first coordinate system and the origins of the second coordinate system at each motion time point respectively, and determining the vector coordinates of the at least three reference points at each motion time point;

[0105] determining the rotation degrees of freedom of the wheel center around the X and Z axis directions according to the vector coordinates of the at least three reference points at each motion time point;

[0106] taking the movement degrees of freedom of the wheel center along the X, Y and Z axis directions and the rotation degrees of freedom of the wheel center around the X and Z axis directions as the five-degree-of-freedom parameters of the wheel center.

[0107] In the embodiment of the present application, the wheel center of each motion moment corresponds to a three-dimensional coordinate, and the difference between the three-dimensional coordinate and the three-dimensional coordinate before the sample vehicle moves is the movement freedom of the wheel center along the X, Y and Z axis directions at each motion moment, and the first angle between the vector coordinate of the reference point at any point in the first coordinate system (i.e. the three-dimensional coordinate) and the X, Y and Z axes is obtained by the projection method, and the second angle between the vector coordinate of the reference point in the second coordinate system at the current motion moment and the X, Y and Z axes is obtained, and the first angle between the vector coordinate of the reference point and the X, Y and Z axes and the second angle between the vector coordinate of the reference point and the X, Y and Z axes are subjected to difference operation, so that the rotation angle of the wheel center around the X, Y and Z axes is obtained. Since the wheel is round, the rotation around the Y axis direction does not need to be concerned, and only the rotation freedom of the wheel center around the X and Z axis directions needs to be concerned.

[0108] In an alternative embodiment, the first coordinate system is established based on the sample vehicle before movement, and the three-dimensional coordinates of at least three reference points in the first coordinate system before movement of the sample vehicle are obtained, specifically comprising:

[0109] The at least three reference points are tracked in real time by a shooting device, the first coordinate system is established based on the sample vehicle before movement, and the three-dimensional coordinates of at least three reference points in the first coordinate system before movement of the sample vehicle are obtained based on the shooting picture;

[0110] The second coordinate system which changes in real time with the movement of the sample vehicle is established based on the sample vehicle moving in a preset driving condition, and the three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion moment are obtained, specifically comprising:

[0111] The second coordinate system which changes in real time with the movement of the sample vehicle is established based on the sample vehicle moving in a preset driving condition, and the three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion moment are obtained based on the shooting picture.

[0112] In the embodiment of the present application, the motion trajectories of the at least three reference points are collected by a shooting device, and the shooting device is installed on the sample vehicle.

[0113] In an alternative embodiment, the shooting device is a high-speed camera. Since the high-speed camera can complete rapid and multiple sampling of high-speed targets in a very short time, when played at a conventional speed, the change process of the recorded target is clearly and slowly presented in front of our eyes. Therefore, in order to accurately capture the position change of the reference point, in the embodiment of the present application, the position change of the reference point of the sample vehicle is collected by the high-speed camera, and then the tire motion parameters are analyzed by using the position change of the reference point, and a five-degree-of-freedom parameterized point-line model based on Euler angle motion is established, and the tire motion parameters are input into the five-degree-of-freedom parameterized point-line model, so that the accurate tire motion envelope is obtained.

[0114] In the embodiment of the present application, the step S4 "inputting the five-degree-of-freedom parameters of the wheel center into a pre-built five-degree-of-freedom parameterized point-line model, and running the five-degree-of-freedom parameterized point-line model to obtain the tire envelope result" in the specific implementation can be constructed according to the five-degree-of-freedom parameter point-line model components and the joint design table in Table 1 below, and the five-degree-of-freedom parameters of the wheel center corresponding to each motion moment are input into the model, and the tire envelope result can be obtained.

[0115] Table 1 five-degree-of-freedom parameter point-line model components and joint design table

[0116]

[0117] Correspondingly, Figure 3 is a structural block diagram of a vehicle tire envelope design device provided by the embodiment of the present application. The embodiment of the present application also provides a vehicle tire envelope design device for executing all steps and processes of the above vehicle tire envelope design, including:

[0118] The reference point motion trajectory tracking module 110 is configured to track the motion trajectory of at least three reference points selected on the wheels of the sample vehicle in the process of the sample vehicle moving in the preset driving condition in real time.

[0119] The wheel center trajectory determination module 120 is configured to determine the motion trajectory of the wheel center according to the motion trajectory of the at least three reference points in the process of the sample vehicle moving in the preset driving condition.

[0120] The five-degree-of-freedom parameter acquisition module 130 is configured to obtain the five-degree-of-freedom parameters of the wheel center according to the motion trajectory of the wheel center.

[0121] The tire envelope acquisition module 140 is configured to input the five-degree-of-freedom parameters of the wheel center into a pre-built five-degree-of-freedom parameterized point-line model, and run the five-degree-of-freedom parameterized point-line model to obtain the tire envelope result.

[0122] In an optional embodiment, the reference point motion trajectory tracking module 110 is specifically configured to:

[0123] establish a first coordinate system based on the sample vehicle before motion, and obtain the three-dimensional coordinates of the at least three reference points in the first coordinate system before the sample vehicle moves;

[0124] establish a second coordinate system that changes in real time with the sample vehicle moving based on the sample vehicle moving in the preset driving condition, and obtain the three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion moment.

[0125] In an alternative embodiment, the wheel center trajectory determination module 120 is specifically configured to:

[0126] obtain a three-dimensional coordinate of a wheel center reference position with a preset wheel center distance in the first coordinate system; wherein the wheel center reference position is located on the rotation axis of the wheel;

[0127] determine a three-dimensional coordinate of the wheel center in the first coordinate system according to the three-dimensional coordinate of the wheel center reference position in the first coordinate system;

[0128] determine a three-dimensional coordinate of the wheel center reference position in the second coordinate system at each motion time according to the three-dimensional coordinate of the wheel center reference position in the first coordinate system, the three-dimensional coordinates of the at least three reference points in the first coordinate system before the motion of the sample vehicle, and the three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion time;

[0129] determine a three-dimensional coordinate of the wheel center in the second coordinate system at each motion time according to the three-dimensional coordinate of the wheel center reference position in the second coordinate system at each motion time.

[0130] In an alternative embodiment, the determination of the three-dimensional coordinate of the wheel center reference position in the second coordinate system at each motion time according to the three-dimensional coordinate of the wheel center reference position in the first coordinate system, the three-dimensional coordinates of the at least three reference points in the first coordinate system before the motion of the sample vehicle, and the three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion time specifically includes:

[0131] for each motion time, the following wheel center reference position determination operation is performed:

[0132] determine a translation vector of the at least three reference points on the X, Y, Z axes at the current motion time according to the three-dimensional coordinates of the at least three reference points in the first coordinate system before the motion of the sample vehicle and the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion time;

[0133] determine a translation vector corresponding to the current wheel center reference position according to the translation vector of the at least three reference points on the X, Y, Z axes at the current motion time;

[0134] determine an anti-symmetric matrix corresponding to the current wheel center reference position according to the three-dimensional coordinates of the at least three reference points in the first coordinate system before the motion of the sample vehicle and the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion time;

[0135] construct a rotation matrix corresponding to the current wheel center reference position according to the anti-symmetric matrix corresponding to the current wheel center reference position.

[0136] determining the three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion moment according to the translation vector corresponding to the current wheel center reference position, the rotation matrix corresponding to the current wheel center reference position, and the three-dimensional coordinates of the wheel center reference position in the first coordinate system.

[0137] In an optional implementation, the determining the skew-symmetric matrix corresponding to the current wheel center reference position according to the three-dimensional coordinates of the at least three reference points in the first coordinate system before the sample vehicle moves and the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion moment specifically comprises:

[0138] selecting three reference points from the at least three reference points as operation reference points; for example, the three operation reference points are a first operation reference point, a second operation reference point and a third operation reference point;

[0139] determining the skew-symmetric matrix corresponding to the current wheel center reference position through formulas (1) and (2):

[0140]

[0141]

[0142] wherein S is the skew-symmetric matrix corresponding to the current wheel center reference position, Xi and Xj are the coordinate difference values of the operation reference point i and the operation reference point j on the X-axis in the first coordinate system, for example, Xi and Xj are the coordinate difference values of the first operation reference point and the second operation reference point on the X-axis in the first coordinate system; Yi and Yj are the coordinate difference values of the operation reference point i and the operation reference point j on the Y-axis in the first coordinate system; Zi and Zj are the coordinate difference values of the operation reference point i and the operation reference point j on the Z-axis in the first coordinate system; Xi' and Xj' are the coordinate difference values of the operation reference point i and the operation reference point j on the X-axis in the second coordinate system at the current motion moment, for example, Xi' and Xj' are the coordinate difference values of the first operation reference point and the second operation reference point on the X-axis in the second coordinate system; Yi' and Yj' are the coordinate difference values of the operation reference point i and the operation reference point j on the Y-axis in the second coordinate system at the current motion moment; and Zj' and Zj' are the coordinate difference values of the operation reference point i and the operation reference point j on the Z-axis in the second coordinate system at the current motion moment. Aij A12 Aij Aij Bij B12 Bij Bij

[0143] the constructing the rotation matrix corresponding to the current wheel center reference position according to the skew-symmetric matrix corresponding to the current wheel center reference position specifically comprises:​​​​​​​​

[0144] A rotation matrix corresponding to the current wheel center reference position is constructed by formula (3):

[0145]

[0146] wherein R is a rotation matrix corresponding to the current wheel center reference position, and I is a unit matrix.

[0147] In an optional implementation, the determining of the three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion moment according to the translation vector corresponding to the current wheel center reference position, the rotation matrix corresponding to the current wheel center reference position, and the three-dimensional coordinates of the wheel center reference position in the first coordinate system specifically comprises:

[0148] The three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion moment are calculated by formula (4):

[0149]

[0150] wherein, is the three-dimensional coordinates of the wheel center reference position in the first coordinate system, is a translation vector corresponding to the current wheel center reference position, and R is a rotation matrix corresponding to the current wheel center reference position, is the three-dimensional coordinates of the wheel center reference position in the second coordinate system.

[0151] In an optional implementation, the five-degree-of-freedom parameter acquisition module 130 is specifically configured to:

[0152] determine the movement degrees of freedom of the wheel center along the X, Y, and Z axis directions according to the three-dimensional coordinates of the wheel center in the first coordinate system and the three-dimensional coordinates of the wheel center in the second coordinate system at each motion moment;

[0153] determine the vector coordinates of the at least three reference points at each motion moment by coinciding the origin of the first coordinate system with the origin of the second coordinate system at each motion moment;

[0154] determine the rotation degrees of freedom of the wheel center around the X and Z axis directions according to the vector coordinates of the at least three reference points at each motion moment;

[0155] take the movement degrees of freedom of the wheel center along the X, Y, and Z axis directions and the rotation degrees of freedom of the wheel center around the X and Z axis directions as the five-degree-of-freedom parameters of the wheel center.

[0156] It should be noted that the vehicle tire envelope design device described above is used to perform all steps and processes of the vehicle tire envelope design of the above-described embodiments, and the principles and effects of the two are one-to-one correspondence, and here will not be too much repetition.

[0157] In addition, the device embodiments described above are only illustrative, wherein the units illustrated as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment scheme according to actual needs. In addition, the connection relationship between the modules in the device embodiment figure of the present application indicates that there is a communication connection between them, which can be realized as one or more communication buses or signal lines. Those skilled in the art can understand and implement it without creative labor.

[0158] The above is the preferred embodiment of the present application, it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, which are also considered within the scope of protection of the present application.

Claims

1. A method of vehicle tire envelope design, characterized by, The method comprises: tracking the movement trajectory of at least three reference points selected on the wheel of the sample vehicle in the process of movement of the sample vehicle in a preset driving condition; determining the movement trajectory of the wheel center according to the movement trajectory of the at least three reference points in the process of movement of the sample vehicle in the preset driving condition; obtaining the five-degree-of-freedom parameters of the wheel center according to the movement trajectory of the wheel center; inputting the five-degree-of-freedom parameters of the wheel center into a pre-established five-degree-of-freedom parameterized point-line model, and running the five-degree-of-freedom parameterized point-line model to obtain the tire envelope result; wherein the obtaining of the five-degree-of-freedom parameters of the wheel center according to the movement trajectory of the wheel center comprises: determining the movement freedom of the wheel center along the X, Y and Z axis directions according to the three-dimensional coordinates of the wheel center in the first coordinate system and the three-dimensional coordinates of the wheel center in the second coordinate system at each movement time; wherein the first coordinate system is established based on the sample vehicle before movement; and the second coordinate system is a coordinate system that changes in real time with the movement of the sample vehicle; determining the vector coordinates of the at least three reference points at each movement time by coinciding the origins of the first coordinate system and the origins of the second coordinate system at each movement time; determining the rotation freedom of the wheel center around the X and Z axis directions according to the vector coordinates of the at least three reference points at each movement time; taking the movement freedom of the wheel center along the X, Y and Z axis directions and the rotation freedom of the wheel center around the X and Z axis directions as the five-degree-of-freedom parameters of the wheel center.

2. The vehicle tire envelope design method of claim 1 wherein, The tracking of the movement trajectory of the at least three reference points selected on the wheel of the sample vehicle in the process of movement of the sample vehicle in a preset driving condition comprises: establishing the first coordinate system based on the sample vehicle before movement, and obtaining the three-dimensional coordinates of the at least three reference points in the first coordinate system before movement of the sample vehicle; establishing the second coordinate system that changes in real time with the movement of the sample vehicle based on the sample vehicle moving in a preset driving condition, and obtaining the three-dimensional coordinates of the at least three reference points in the second coordinate system at each movement time.

3. The vehicle tire envelope design method of claim 2 wherein, The determining of the movement trajectory of the wheel center according to the movement trajectory of the at least three reference points in the process of movement of the sample vehicle in a preset driving condition comprises: obtaining the three-dimensional coordinates of the wheel center reference position in the first coordinate system; wherein the wheel center reference position is located on the rotation axis of the wheel; determining the three-dimensional coordinates of the wheel center in the first coordinate system according to the three-dimensional coordinates of the wheel center reference position in the first coordinate system; determining the three-dimensional coordinates of the wheel center reference position in the second coordinate system at each movement time according to the three-dimensional coordinates of the wheel center reference position in the first coordinate system, the three-dimensional coordinates of the at least three reference points in the first coordinate system before movement of the sample vehicle, and the three-dimensional coordinates of the at least three reference points in the second coordinate system at each movement time; determining the three-dimensional coordinates of the wheel center in the second coordinate system at each movement time according to the three-dimensional coordinates of the wheel center reference position in the second coordinate system at each movement time.

4. The vehicle tire envelope design method of claim 3 wherein, The three-dimensional coordinates of the wheel center reference position in the second coordinate system at each motion moment are determined according to the three-dimensional coordinates of the wheel center reference position in the first coordinate system, the three-dimensional coordinates of the at least three reference points in the first coordinate system before the motion of the sample vehicle, and the three-dimensional coordinates of the at least three reference points in the second coordinate system at each motion moment, and specifically include the following steps: For each motion moment, the following wheel center reference position determination operation is performed: Determine the translation vectors of the at least three reference points on the X, Y and Z axes at the current motion moment according to the three-dimensional coordinates of the at least three reference points in the first coordinate system before the motion of the sample vehicle and the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion moment; Determine the translation vector corresponding to the current wheel center reference position according to the translation vectors of the at least three reference points on the X, Y and Z axes at the current motion moment; Determine the skew-symmetric matrix corresponding to the current wheel center reference position according to the coordinate difference values of the three-dimensional coordinates of the at least three reference points in the first coordinate system before the motion of the sample vehicle and the coordinate difference values of the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion moment; Construct the rotation matrix corresponding to the current wheel center reference position according to the skew-symmetric matrix corresponding to the current wheel center reference position; Determine the three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion moment according to the translation vector corresponding to the current wheel center reference position, the rotation matrix corresponding to the current wheel center reference position, and the three-dimensional coordinates of the wheel center reference position in the first coordinate system.

5. The vehicle tire envelope design method of claim 4 wherein, The skew-symmetric matrix corresponding to the current wheel center reference position is determined according to the coordinate difference values of the three-dimensional coordinates of the at least three reference points in the first coordinate system before the motion of the sample vehicle and the coordinate difference values of the three-dimensional coordinates of the at least three reference points in the second coordinate system at the current motion moment, and specifically includes the following steps: Select three reference points from the at least three reference points as operation reference points; Determine the skew-symmetric matrix corresponding to the current wheel center reference position by the following formula: wherein, S is an anti-symmetric matrix corresponding to the current wheel center reference position, X Aij is an operation reference point i and an operation reference point j a coordinate difference value on the X-axis in the first coordinate system, Y Aij is an operation reference point i and an operation reference point j a coordinate difference value on the Y axis in the first coordinate system, Z Aij is an operation reference point i and an operation reference point j a coordinate difference value on the Z axis in the first coordinate system; X Bij is an operation reference point i and an operation reference point j a coordinate difference value on the X axis in the second coordinate system at the current motion time, Y Bij is an operation reference point i and an operation reference point j a coordinate difference value on the Y axis in the second coordinate system at the current motion time, Z Bij is an operation reference point i and an operation reference point j a coordinate difference value on the Z axis in the second coordinate system at the current motion time; The rotation matrix corresponding to the current wheel center reference position is constructed according to the skew-symmetric matrix corresponding to the current wheel center reference position, and specifically includes the following steps: The rotation matrix corresponding to the current wheel center reference position is constructed by the following formula: wherein, R is the rotation matrix corresponding to the current wheel center reference position, I is the identity matrix.

6. The vehicle tire envelope design method of claim 5 wherein, Determine the three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion moment according to the translation vector corresponding to the current wheel center reference position, the rotation matrix corresponding to the current wheel center reference position, and the three-dimensional coordinates of the wheel center reference position in the first coordinate system, and specifically includes the following steps: The three-dimensional coordinates of the wheel center reference position in the second coordinate system at the current motion moment are calculated by the following formula: wherein, is a three-dimensional coordinate of the wheel center reference position in the first coordinate system, is a translation vector corresponding to the current wheel center reference position, is a rotation matrix corresponding to the current wheel center reference position, is a three-dimensional coordinate of the wheel center reference position in the second coordinate system.

7. The vehicle tire envelope design method of claim 2 wherein, The first coordinate system is established based on the sample vehicle before the motion, and the three-dimensional coordinates of at least three reference points in the first coordinate system before the motion of the sample vehicle are obtained, and specifically includes the following steps: The at least three reference points are tracked in real time by a shooting device, a first coordinate system is established based on a sample vehicle before movement, and three-dimensional coordinates of the at least three reference points in the first coordinate system before movement of the sample vehicle are obtained based on a shooting picture; The second coordinate system which changes in real time with movement of the sample vehicle is established based on the sample vehicle moving in a preset driving condition, and three-dimensional coordinates of the at least three reference points in the second coordinate system at each movement moment are obtained, specifically including: The second coordinate system which changes in real time with movement of the sample vehicle is established based on the sample vehicle moving in a preset driving condition, and three-dimensional coordinates of the at least three reference points in the second coordinate system at each movement moment are obtained based on a shooting picture.

8. The vehicle tire envelope design method of claim 7 wherein, The shooting device is a high-speed camera.

9. A vehicle tire envelope design apparatus characterized by, The method comprises: A reference point movement trajectory tracking module is configured to track movement trajectories of at least three reference points selected on wheels of a sample vehicle during movement of the sample vehicle in a preset driving condition in real time; A wheel center movement trajectory determination module is configured to determine a movement trajectory of a wheel center according to the movement trajectories of the at least three reference points during movement of the sample vehicle in the preset driving condition; A wheel center five-degree-of-freedom parameter acquisition module is configured to obtain five-degree-of-freedom parameters of the wheel center according to the movement trajectory of the wheel center; A tire envelope acquisition module is configured to input the five-degree-of-freedom parameters of the wheel center into a pre-established five-degree-of-freedom parameterized point-line model, and run the five-degree-of-freedom parameterized point-line model to obtain a tire envelope result; The five-degree-of-freedom parameters of the wheel center are obtained according to the movement trajectory of the wheel center, specifically including: Three-dimensional coordinates of the wheel center in a first coordinate system and three-dimensional coordinates of the wheel center in a second coordinate system at each movement moment are determined to determine movement degrees of freedom of the wheel center along X, Y and Z axes, wherein the first coordinate system is established based on the sample vehicle before movement, and the second coordinate system is a coordinate system which changes in real time with movement of the sample vehicle; The origin of the first coordinate system is coincided with the origin of the second coordinate system at each movement moment to determine vector coordinates of the at least three reference points at each movement moment; The vector coordinates of the at least three reference points at each movement moment are determined to determine rotation degrees of freedom of the wheel center around X and Z axes; The movement degrees of freedom of the wheel center along X, Y and Z axes and the rotation degrees of freedom of the wheel center around X and Z axes are taken as the five-degree-of-freedom parameters of the wheel center.

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