Road surface model reconstruction method, suspension height control method and related device

Abstract

The invention relates to a road surface model reconstruction method, a suspension height control method and a related device, and relates to the technical field of vehicle chassis suspensions, the method comprises the following steps: obtaining vehicle state information, and obtaining vehicle tire track information and road surface information based on the vehicle state information; performing coordinate fusion on the tire track information and the road surface information to obtain height information of the tire of the corresponding sampling point; according to the height information of the tire at the sampling point, a road surface model is obtained, and the road surface model is used for fitting the height information of the tire at the sampling point. In this way, the road surface model can accurately obtain the height information of the tire under various road conditions, so that the control quantity of the vehicle suspension can be determined based on the road surface model, vibration from the ground is better buffered, the adaptability to the road surface and the road conditions is improved, and the riding experience feeling is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle chassis suspension, and in particular to a road surface model reconstruction method, a suspension height control method and related devices. Background Art

[0002] Suspension is the general term for all force-transmitting connection devices between the frame, body and axle or wheels of a car. Its function is to transmit the force and torque acting between the wheels and the frame, and to cushion the impact force transmitted to the frame or body by uneven roads, and reduce the vibration caused by it, so as to ensure that the car can run smoothly.

[0003] In the related technology, the suspension is generally divided into non-independent suspension, independent suspension and other types according to the structure of the suspension to buffer the vibration from the ground. However, the actual road conditions are more complex and changeable, and the related suspension control technology lacks the ability to identify the real-time road conditions and has poor ability to adapt to various road conditions, and the riding experience needs to be improved. Summary of the invention

[0004] The present invention provides a road surface model reconstruction method, a suspension height control method and related devices, which improve the problem of low adaptability of chassis suspension to road conditions in related technologies.

[0005] In a first aspect, the present invention provides a road surface model reconstruction method, the method comprising: Acquiring vehicle status information, and obtaining tire track information and road surface information of the vehicle based on the vehicle status information; The tire track information and the road surface information are coordinate-fused to obtain the height information of the tire corresponding to the sampling point; A road surface model is acquired according to the height information of the tire at the sampling point, wherein the road surface model is used to fit the height information of the tire at the sampling point.

[0006] Optionally, the step of fusing the tire track information and the road surface information to obtain tire height information corresponding to a sampling point includes: Fusing the tire track information with the road surface information, and projecting the tire track information onto the road surface information after the coordinate fusion to obtain projection track information of the tire; Based on the projection trajectory information, height information of the tire at the sampling point is obtained.

[0007] Optionally, acquiring the height information of the tire at the sampling point based on the projection trajectory information includes: Acquire tire width information, and obtain a tire footprint area based on the tire width information and the projection trajectory information, wherein the tire footprint area includes a plurality of tire footprint point sets, and the tire footprint point sets correspond one-to-one to the sampling points in the projection trajectory information; Based on the contact state between the tire and each point in the tire mark point set, the projection trajectory information corresponding to the sampling point is corrected, and based on the corrected projection trajectory information, the height information of the tire at the sampling point is obtained.

[0008] Optionally, acquiring the road surface model according to the tire height information at the sampling point includes: Dividing the tire track according to the height information of the tire at the sampling point to obtain a plurality of track segments, each of the plurality of track segments including a plurality of discrete sampling points; Selecting a preset number of sampling points from each of the plurality of trajectory segments for reconstruction to obtain a reconstruction curve of each trajectory segment, wherein the curvatures of the reconstruction curves of any two adjacent trajectory segments at the connection points are equal, and the connection points are the sampling points selected from the corresponding two trajectory segments; The road surface model is obtained based on the reconstructed curve of each trajectory segment.

[0009] Optionally, the vehicle state information includes vehicle longitudinal speed, steering wheel angle, vehicle mass, vehicle front axle wheelbase, vehicle rear axle wheelbase, vehicle front wheel cornering stiffness, vehicle rear wheel cornering stiffness, vehicle inertia moment and road surface perception information; The obtaining of tire track information and road surface information of the vehicle based on the vehicle state information comprises: Based on the longitudinal speed of the vehicle, the steering wheel angle, the vehicle mass, the front axle wheelbase of the vehicle, the rear axle wheelbase of the vehicle, the front wheel cornering stiffness of the vehicle, the rear wheel cornering stiffness of the vehicle and the moment of inertia of the vehicle, the vehicle body trajectory information is calculated, and the vehicle body trajectory information is coordinate-converted to obtain the tire trajectory information, wherein the vehicle body trajectory information is used to characterize the heading angle and position coordinates of the vehicle at each time point in a preset time period in the future; Based on the road surface perception information, the road surface information is obtained.

[0010] In a second aspect, the present invention further provides a suspension height control method, the method comprising: The road surface model obtained by the road surface model reconstruction method described in any one of the first aspects is used to control the height of the suspension so that the chassis height changes with the height of the suspension.

[0011] In a third aspect, the present invention further provides a road surface model reconstruction device, the device comprising: A first acquisition module, used to acquire vehicle status information, and obtain tire track information and road surface information of the vehicle based on the vehicle status information; A coordinate fusion module, used to coordinately fuse the tire track information and the road surface information to obtain tire height information corresponding to a sampling point; The second acquisition module is used to acquire a road surface model according to the height information of the tire at the sampling point, wherein the road surface model is used to fit the height information of the tire at the sampling point.

[0012] In a fourth aspect, the present invention further provides a new energy vehicle, the new energy vehicle comprising: A vehicle sensing device, used to obtain vehicle status information; A road surface model reconstruction device, used to obtain tire track information and road surface information of the vehicle based on the vehicle state information; coordinately fuse the tire track information and the road surface information to obtain height information of the tire corresponding to the sampling point; and obtain a road surface model according to the height information of the tire at the sampling point, wherein the road surface model is used to fit the height information of the tire at the sampling point; The suspension control device is used to control the height of the suspension using the road surface model so that the chassis height changes following the height of the suspension.

[0013] In a fifth aspect, the present invention further provides an electronic device, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; Memory, used to store computer programs; The processor is used to implement the road surface model reconstruction method described in the first aspect or the suspension height control method described in the second aspect when executing the program stored in the memory.

[0014] In a sixth aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the road surface model reconstruction method described in the first aspect or the suspension height control method described in the second aspect is implemented.

[0015] The above technical solution provided by the present invention has the following advantages over the prior art: the method provided by the present invention obtains vehicle status information, and obtains the tire track information and road surface information of the vehicle based on the vehicle status information; coordinates the tire track information and the road surface information to obtain the height information of the tire corresponding to the sampling point; and obtains the road surface model according to the height information of the tire at the sampling point, wherein the road surface model is used to fit the height information of the tire at the sampling point. In the above manner, the tire track information and road surface information of the vehicle can be used to obtain the height information of the tire at the corresponding sampling point, and then the road surface model can be obtained according to the height information of the tire at the sampling point, so that the road surface model can accurately obtain the height information of the tire under various road conditions, so that the control amount of the vehicle suspension can be determined based on the road surface model, so as to better buffer the vibration from the ground, improve the adaptability to the road surface and road conditions, and increase the riding experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0019] Figure 1 A schematic flow chart of a road surface model reconstruction method provided by an embodiment of the present invention; Figure 2 A schematic diagram of projecting tire track information onto road surface information provided by an embodiment of the present invention; Figure 3 A schematic diagram of correcting projection trajectory information provided by an embodiment of the present invention; Figure 4 A side view of the corrected projection trajectory information provided by an embodiment of the present invention; Figure 5 A schematic diagram of reconstruction using a Bezier curve provided by an embodiment of the present invention; Figure 6 A schematic diagram of tire track information provided by an embodiment of the present invention; Figure 7 A schematic flow chart of a suspension height control method provided by an embodiment of the present invention; Figure 8 A schematic structural diagram of a road surface model reconstruction device provided by an embodiment of the present invention; Fig. 9 A schematic diagram of the structure of a new energy vehicle provided by an embodiment of the present invention; Fig.10 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0022] The suspension of a car is used to cushion the vibrations generated by the ground. Due to the complex road conditions, the posture and acceleration of the suspension and car body will change with the changes in road conditions, affecting the riding experience.

[0023] Active suspension technology can be used to adjust the suspension's posture to adapt to changes in road conditions. For example, by sensing the vibrations generated by the ground, information such as the impact force and impact acceleration corresponding to the vibrations can be obtained, and the height of the suspension can be adjusted to adapt to the ups and downs of road conditions. This allows the vehicle body and the cabin connected to the vehicle body to be in a stable state, thereby improving the riding experience. However, the method of adjusting the suspension by sensing vibrations from the ground has low adaptability to road conditions.

[0024] In order to solve the problem of low adaptability of chassis suspension to road conditions in related technologies, the present invention provides a method for reconstructing a road model, which obtains the height information of the tire at the corresponding sampling point by obtaining vehicle status information, determining tire track information and road information, and performing coordinate fusion, and obtains the road model according to the tire height information at the sampling point. The road model can reflect the height information of the road surface on which the vehicle is about to travel, and based on the height information, before the tire vibrates with the ground, the height of the suspension is controlled to reduce the impact force and impact acceleration corresponding to the vibration, thereby improving the stability of the chassis and the riding experience.

[0025] See also Figure 1 , Figure 1 A schematic diagram of a process flow of a road surface model reconstruction method provided by an embodiment of the present invention. Figure 1 As shown, the road surface model reconstruction method may include the following steps: Step S101: Acquire vehicle status information, and obtain tire track information and road surface information of the vehicle based on the vehicle status information.

[0026] Specifically, the above vehicle state information may include, but is not limited to, vehicle longitudinal speed, steering wheel angle, vehicle mass, vehicle front axle wheelbase, vehicle rear axle wheelbase, vehicle front wheel lateral stiffness, vehicle rear wheel lateral stiffness, vehicle inertia moment, and road surface perception information acquired by the vehicle. When acquiring vehicle state information, for real-time changing information (such as speed, steering wheel angle, road surface perception information, etc.), it can be acquired in real time according to sensors on the vehicle; for fixed information (such as lateral stiffness, front and rear axle wheelbase, etc.), it can be determined according to vehicle model or experimental data. After acquiring vehicle state information, tire track information and road surface information of the vehicle can be obtained based on the vehicle state information. Specifically, the vehicle state information can be input into a vehicle dynamics prediction model to predict the running state of the vehicle in a preset period of time in the future, and obtain the tire track information of the vehicle. It should be noted that in order to simplify the vehicle dynamics prediction model, the influence of road height changes can be ignored, and only the lateral movement and longitudinal movement of the vehicle are considered, so that the vehicle body track information obtained is a two-dimensional motion track. The vehicle dynamics prediction model here can be any vehicle kinematic model or any vehicle dynamics model. As an optional implementation, the vehicle dynamics prediction model can be a vehicle differential dynamics prediction model. At the same time, the road surface information in the vehicle driving direction can also be obtained based on the road surface perception information in the vehicle state information. The road surface information at least includes information such as the ups and downs of the road and the flatness.

[0027] Step S102: coordinate fusion of the tire track information and the road surface information to obtain tire height information corresponding to the sampling point.

[0028] After the tire track information and the road surface information are obtained, the tire track information and the road surface information can be coordinate-fused so that the tire track information and the road surface information are in the same coordinate system, and then the height information of the tire corresponding to the sampling point is obtained based on the projection of the tire track information on the road surface information.

[0029] Step S103: acquiring a road surface model according to the tire height information at the sampling point, wherein the road surface model is used to fit the tire height information at the sampling point.

[0030] After obtaining the height information of the tires at the corresponding sampling points, the height information of the tires at the sampling points can be fitted to obtain a curve used to characterize the height change of the tires, thereby obtaining a road surface model. In other words, the road surface model is not represented by a three-dimensional surface, but by a two-dimensional curve of the tire height change corresponding to each wheel. In addition, the road surface model can reflect the height information of the road surface on which the vehicle is about to travel, and based on the height information, the height of the suspension is controlled before the tires vibrate with the ground, thereby reducing the impact force and impact acceleration corresponding to the vibration.

[0031] In this embodiment, the tire track information and road surface information of the vehicle can be used to obtain the height information of the tire at the corresponding sampling point, and then the road surface model can be obtained based on the tire height information at the sampling point, so that the road surface model can accurately obtain the tire height information under various road conditions, so that the control amount of the vehicle suspension can be determined based on the road surface model, better buffering the vibration from the ground, improving the adaptability to the road surface and road conditions, and enhancing the riding experience.

[0032] Furthermore, the above step S102, performing coordinate fusion of the tire track information and the road surface information to obtain the height information of the tire corresponding to the sampling point, includes: The tire track information and the road surface information are coordinate-fused, and after the coordinate fusion, the tire track information is projected onto the road surface information to obtain the projection track information of the tire; Based on the projection trajectory information, the height information of the tire at the sampling point is obtained.

[0033] In one embodiment, when obtaining the height information of the tire corresponding to the sampling point, the tire track information and the road surface information can be coordinate fused, and after the coordinate fusion, the tire track information can be projected onto the road surface information to obtain the projection track information of the tire, and then the height information of the tire at the sampling point can be obtained based on the projection track information. For example, assuming that the road surface information is a three-dimensional surface, which is represented as ,in, are local coordinates on the 3D surface, Represents local coordinates The three-dimensional coordinates of Represents local coordinates The coordinate on the X axis, Represents local coordinates The coordinate on the Y axis, Represents local coordinates The coordinates on the Z axis. After the tire track information and road surface information are fused, Figure 2 As shown, at this time, the plane space projection algorithm (such as Matlab drawing toolbox or open source projection algorithm tool, etc.) can be used to project the tire track information onto the road surface information, so as to obtain the projection track information , where N is any positive integer, represents the three-dimensional coordinates of the first sampling point, represents the three-dimensional coordinates of the second sampling point, In this way, the height information of the tire at the sampling point can be directly or indirectly determined based on the projection trajectory information.

[0034] In the above manner, the height information of the tire corresponding to the sampling point can be accurately determined according to the tire track information and the road surface information, so as to facilitate the subsequent acquisition of the road surface model according to the tire height information of the sampling point.

[0035] Furthermore, the above step of obtaining the tire height information of the sampling point based on the projection trajectory information includes: Acquire tire width information, and obtain a tire footprint area based on the tire width information and the projection trajectory information, wherein the tire footprint area includes a plurality of tire footprint point sets, and the tire footprint point sets correspond one-to-one to the sampling points in the projection trajectory information; Based on the contact state between the tire and each point in the tire mark point set, the projection trajectory information of the corresponding sampling point is corrected, and based on the corrected projection trajectory information, the height information of the tire at the sampling point is obtained.

[0036] In one embodiment, since the projection trajectory information corresponding to each wheel reflects only the contact point trajectory between the center point of each wheel periphery and the road surface, it cannot truly reflect the contact situation between the entire wheel and the road surface, so that there is a deviation between the projection trajectory information corresponding to each wheel and the actual height information of each tire. Therefore, in this embodiment, the height information of the tire at the sampling point is not directly determined based on the projection trajectory information, but the projection trajectory information is corrected according to the contact state of each point on the tire width information to obtain the height information of the tire at the sampling point. Specifically, the tire width information can be obtained first, and the tire mark area can be obtained based on the tire width information and the projection trajectory information. Then, based on the contact state between the tire and each point in the tire mark point set, the projection trajectory information corresponding to the sampling point is corrected, and the height information of the tire at the sampling point is obtained based on the corrected projection trajectory information.

[0037] like Figure 2 As shown, the sampling points in the projection trajectory information and the tire mark boundary points that are relatively offset from the projection trajectory information can be combined to form a tire mark point set, which can be specifically expressed as ,in, represents the tire mark boundary point on the left side of the i-th tire mark point set, represents the sampling point in the middle of the i-th tire mark point set, Indicates the tire mark boundary point on the right side of the i-th tire mark point set. Finally, the tire mark area of ​​a single wheel can be obtained. ,in represents the first tire mark point set, represents the second tire mark point set, Represents the i-th tire mark point set. According to the tire mark area , the contact state between the vehicle's wheels and the road surface at each discrete time point can be estimated, such as the tire's contact area, contact pressure, contact angle and other parameters.

[0038] For the sake of simplicity in calculation, the tire can be assumed to be a rigid body, so only the geometric relationship is considered. According to the geometric relationship and the contact state between the wheel and the road surface, the projection trajectory information of each wheel can be corrected, such as Figure 3 As shown. Figure 3 middle, Indicates the height value of the tire mark boundary point on the left side of a tire mark point set. Indicates the height value of the tire mark boundary point on the right side of a tire mark point set. Indicates the height value of the sampling point in the middle of a tire mark point set. , and The position relationship of each wheel can be obtained .

[0039] Through forward discrete prediction, the corrected projection trajectory information of each wheel can be obtained, such as Figure 4 According to the corrected projection trajectory information of each wheel, the three-dimensional trajectory corresponding to each wheel can be finally determined. ,in, Indicates the X-axis coordinate value of the 0th sampling point. Indicates the Y-axis coordinate value of the 0th sampling point. Indicates the corrected height value of the 0th sampling point. Indicates the X-axis coordinate value of the first sampling point. Indicates the Y-axis coordinate value of the first sampling point. Indicates the corrected height value of the first sampling point. Indicates the X-axis coordinate value of the second sampling point. Indicates the Y-axis coordinate value of the second sampling point. Indicates the corrected height value of the second sampling point. Indicates the X-axis coordinate value of the nth sampling point, Indicates the Y-axis coordinate value of the nth sampling point. Indicates the corrected height value of the nth sampling point. . Convert the entire road model into a point set containing only the Z-axis runout height Ignoring the horizontal movement of the vehicle and only caring about the vertical movement, we can get the three-dimensional trajectory corresponding to each wheel. Determine the tire height information of the sampling point .

[0040] By means of the above method, the projection trajectory information of the corresponding sampling point can be corrected based on the contact state between the tire and each point in the tire mark point set, so that the height information of the tire at the sampling point is more accurate.

[0041] Furthermore, the above step S103, obtaining the road surface model according to the tire height information at the sampling point, includes: According to the height information of the tire at the sampling point, the tire track is divided to obtain a plurality of track segments, each of the plurality of track segments includes a plurality of discrete sampling points; Selecting a preset number of sampling points from each of the multiple trajectory segments for reconstruction to obtain a reconstruction curve of each trajectory segment, wherein the curvatures of the reconstruction curves of any two adjacent trajectory segments at the connection points are equal, and the connection points are the sampling points selected from the corresponding two trajectory segments; Based on the reconstructed curve of each trajectory segment, a road surface model is obtained.

[0042] In one embodiment, in order to further simplify and restore the road surface model, the height information of discrete tires can be reconstructed by using Bezier curves. Specifically, the Bezier curve here can be a Bezier curve of any order, such as a second-order Bezier curve, a third-order Bezier curve, a fourth-order Bezier curve, etc., which is not specifically limited in the embodiment of the present invention. As an optional implementation, in order to balance the accuracy of road surface model reconstruction and the amount of calculation, a third-order Bezier curve can be used to reconstruct multiple discrete road surface height prediction points in the road surface height prediction trajectory corresponding to each wheel. For example, assuming that a third-order Bezier curve is used to restore the road surface, the number of sampling points of each Bezier curve can be set to 4, so that the shape of the curve can be determined by these 4 sampling points, thereby realizing the reconstruction of the road surface model. It should be noted that in order to ensure the continuity of the road surface, it is necessary to limit the curvature of the connection points of the adjacent Bezier curves at both ends to be equal, such as Figure 5 As shown. Among them, the third-order Bezier curve can be expressed by the following formula: , ; in, Indicates the height value of the selected i-th sampling point, i=0,1,2,3, represents a parameter between 0 and 1, t represents time, Represents the value of a third-order Bezier curve that varies with time. Figure 5 As shown, , , , For the first section to be fitted, the sampling points are selected according to the Bessel control node selection method. In order to ensure the continuity of the road surface, As a common sampling point, and the curvature needs to be constrained in Through the above method, the road surface model can be finally obtained as The value of k depends on the density of the fitting. Respectively represent the four sampling points on the first Bezier curve, Respectively represent the four sampling points on the second Bezier curve, In this embodiment, the Bezier curve can be used to reconstruct the tire height information of the sampling points in the three-dimensional trajectory corresponding to each wheel to obtain a road model, further simplify the road model, and convert the road model into a controllable digital model.

[0043] Further, the vehicle state information includes vehicle longitudinal speed, steering wheel angle, vehicle mass, vehicle front axle wheelbase, vehicle rear axle wheelbase, vehicle front wheel cornering stiffness, vehicle rear wheel cornering stiffness, vehicle inertia moment and road surface perception information; The above step S101, obtaining tire track information and road surface information of the vehicle based on the vehicle state information, includes: Based on the longitudinal speed of the vehicle, the steering wheel angle, the vehicle mass, the wheelbase of the front axle of the vehicle, the wheelbase of the rear axle of the vehicle, the cornering stiffness of the front wheels of the vehicle, the cornering stiffness of the rear wheels of the vehicle and the moment of inertia of the vehicle, the vehicle body trajectory information is calculated, and the coordinates of the vehicle body trajectory information are converted to obtain the tire trajectory information, wherein the vehicle body trajectory information is used to characterize the heading angle and position coordinates of the vehicle at each time point in a preset time period in the future; Based on the road surface perception information, road surface information is obtained.

[0044] In one embodiment, when obtaining tire track information, a simple dynamic model of the vehicle can be constructed, assuming that the vehicle itself is a rigid body, and the future state of the vehicle can be predicted using a discrete dynamic difference method. The input of the prediction system is the longitudinal velocity of the vehicle. and steering wheel angle , the output includes the direction, position and other information of the vehicle. Among them, the discrete dynamic difference method can be expressed by the following formula: ; in, represents the lateral acceleration of the vehicle, is the yaw angular acceleration, represents the lateral velocity of the vehicle, represents the yaw angular velocity, represents the longitudinal velocity of the vehicle, Indicates the steering wheel angle, Indicates the vehicle mass, Indicates the front axle wheelbase of the vehicle. Indicates the rear axle wheelbase of the vehicle. Indicates the vehicle's front wheel cornering stiffness, Indicates the vehicle rear wheel cornering stiffness, Represents the vehicle's moment of inertia.

[0045] Through the above formula, the path that the vehicle will take in the next t seconds can be calculated based on the current speed and steering angle of the vehicle. The following is the discrete expression of the vehicle differential dynamics prediction model: ; ; ; ; ; ; ; in, represents the lateral acceleration of the vehicle, represents the lateral velocity of the vehicle at time t, represents the lateral velocity of the vehicle at time t+1, is the yaw angular acceleration, represents the yaw angular velocity, represents the yaw angular velocity corresponding to time t, represents the yaw angular velocity corresponding to time t+1, represents the longitudinal velocity of the vehicle, Indicates the steering wheel angle, Indicates the vehicle mass, Indicates the front axle wheelbase of the vehicle. Indicates the rear axle wheelbase of the vehicle. Indicates the vehicle's front wheel cornering stiffness, Indicates the vehicle rear wheel cornering stiffness, represents the vehicle's moment of inertia, represents the heading angle corresponding to time t, represents the heading angle corresponding to time t+1, represents the horizontal coordinate of the vehicle at time t, represents the horizontal coordinate of the vehicle at time t+1, represents the ordinate of the vehicle at time t, Represents the vertical coordinate of the vehicle at time t+1.

[0046] Next, the vehicle body coordinates and wheel coordinates can be used to convert the vehicle body track information into tire track information corresponding to each wheel. Specifically, the vehicle body coordinates and wheel coordinates conversion relationship is as follows: ; in, represents the wheel coordinates, represents the body coordinates (i.e. the coordinates of the center of the vehicle's rear axle), represents the rotation matrix, Represents translation matrix, rotation matrix and translation matrix It is determined by the vehicle heading angle φ and the body coordinates.

[0047] Assume that the vehicle body trajectory information is ,in, represents the heading angle corresponding to the first moment, represents the horizontal coordinate of the vehicle at the first moment, represents the ordinate of the vehicle at the first moment, represents the heading angle corresponding to the second moment, represents the horizontal coordinate of the vehicle at the second moment, Represents the ordinate of the vehicle at the second moment. Using the conversion relationship between the vehicle body coordinates and wheel coordinates, the tire track information corresponding to each wheel can be obtained, such as Figure 6 As shown, the tire track information corresponding to the rear left wheel can be , represents the horizontal coordinate of the rear left wheel at the first moment, represents the ordinate of the rear left wheel at the first moment, represents the horizontal coordinate of the rear left wheel at the second moment, Represents the ordinate of the rear left wheel at the second moment. In this embodiment, based on the vehicle state information and the vehicle dynamics prediction model, the vehicle body trajectory information within a preset time period in the future can be accurately predicted, and the vehicle body trajectory information can be converted into tire trajectory information corresponding to each wheel, so as to facilitate the subsequent reconstruction of the road model based on the tire trajectory information.

[0048] In addition, the embodiment of the present invention also provides a suspension height control method, such as Figure 7 As shown, the method may include the following steps: Step S701: Use the road surface model to control the height of the suspension so that the chassis height changes with the height of the suspension.

[0049] In one embodiment, the road surface model obtained by the road surface model reconstruction method in the above embodiment can be Provided to the vehicle magic carpet function, the intelligent control algorithm in the vehicle magic carpet function determines the control amount of the vehicle suspension at each time point in the future preset period. Specifically, the proportional-integration-differential (PID), linear quadratic regulator (LQR), fuzzy and other controllers can be used to control the suspension control amount calculated by the main function of the magic carpet function so that the chassis height changes with the height of the suspension. Among them, the parameters of the controller can be adjusted according to the actual situation.

[0050] Through the above method, the calculation amount and hardware requirements of the vehicle's magic carpet function can be effectively reduced, and the comfort and stability of the vehicle in specific environments such as bad weather and complex road conditions can be improved. At the same time, the accuracy of modeling can also be improved, thereby improving the control effect of the suspension.

[0051] See also Figure 8 , Figure 8 The following is a schematic diagram of the structure of a road surface model reconstruction device provided by an embodiment of the present invention. Figure 8 As shown, the road surface model reconstruction device 800 includes: The first acquisition module 801 is used to acquire vehicle status information, and obtain tire track information and road surface information of the vehicle based on the vehicle status information; A coordinate fusion module 802 is used to coordinately fuse the tire track information and the road surface information to obtain the height information of the tire corresponding to the sampling point; The second acquisition module 803 is used to acquire a road surface model according to the height information of the tire at the sampling point, wherein the road surface model is used to fit the height information of the tire at the sampling point.

[0052] Furthermore, the coordinate fusion module 802 includes: A coordinate fusion submodule is used to coordinately fuse the tire track information and the road surface information, and after the coordinate fusion, project the tire track information onto the road surface information to obtain the projection track information of the tire; The first acquisition submodule is used to acquire tire height information of a sampling point based on the projection trajectory information.

[0053] Furthermore, the first acquisition submodule includes: an acquisition unit, configured to acquire tire width information, and obtain a tire footprint area based on the tire width information and the projection track information, wherein the tire footprint area includes a plurality of tire footprint point sets, and the tire footprint point sets correspond one-to-one to the sampling points in the projection track information; The correction unit is used to correct the projection trajectory information of the corresponding sampling point based on the contact state between the tire and each point in the tire mark point set, and obtain the height information of the tire at the sampling point based on the corrected projection trajectory information.

[0054] Further, the second acquisition module 803 includes: A division submodule, used for dividing the tire track according to the height information of the tire at the sampling point to obtain a plurality of track segments, each of the plurality of track segments including a plurality of discrete sampling points; A reconstruction submodule, used for selecting a preset number of sampling points from each of the multiple trajectory segments for reconstruction, to obtain a reconstruction curve of each trajectory segment, wherein the curvatures of the reconstruction curves of any two adjacent trajectory segments at the connection points are equal, and the connection points are the sampling points selected from the corresponding two trajectory segments; The second acquisition submodule is used to acquire a road surface model based on the reconstructed curve of each trajectory segment.

[0055] Further, the vehicle state information includes the vehicle longitudinal speed, the steering wheel angle, the vehicle mass, the vehicle front axle wheelbase, the vehicle rear axle wheelbase, the vehicle front wheel cornering stiffness, the vehicle rear wheel cornering stiffness, the vehicle inertia moment and road surface perception information; the first acquisition module 801 includes: The third acquisition submodule is used to calculate the vehicle body trajectory information based on the vehicle longitudinal speed, the steering wheel angle, the vehicle mass, the vehicle front axle wheelbase, the vehicle rear axle wheelbase, the vehicle front wheel cornering stiffness, the vehicle rear wheel cornering stiffness and the vehicle moment of inertia, and perform coordinate conversion on the vehicle body trajectory information to obtain tire trajectory information, wherein the vehicle body trajectory information is used to characterize the heading angle and position coordinates of the vehicle at various time points in a preset time period in the future; The fourth acquisition submodule is used to obtain road surface information based on road surface perception information.

[0056] It should be noted that the road surface model reconstruction device 800 can implement the road surface model reconstruction method provided by any of the aforementioned method embodiments and can achieve the same technical effects, which will not be described in detail herein.

[0057] like Fig. 9 As shown, an embodiment of the present invention further provides a new energy vehicle, and the new energy vehicle 900 includes: Vehicle sensing device 901, used to obtain vehicle status information; The road surface model reconstruction device 902 is used to obtain the tire track information and road surface information of the vehicle based on the vehicle state information; coordinately fuse the tire track information and the road surface information to obtain the height information of the tire at the corresponding sampling point; obtain the road surface model according to the height information of the tire at the sampling point, wherein the road surface model is used to fit the height information of the tire at the sampling point; The suspension control device 903 is used to control the height of the suspension using the road surface model so that the chassis height changes along with the height of the suspension.

[0058] like Fig.10 As shown, an embodiment of the present invention further provides an electronic device, including a processor 1011, a communication interface 1012, a memory 1013 and a communication bus 1014, wherein the processor 1011, the communication interface 1012, and the memory 1013 communicate with each other through the communication bus 1014. Memory 1013, used for storing computer programs; In one embodiment of the present invention, the processor 1011 is used to implement the road model reconstruction method provided by the aforementioned method embodiment, or implement the suspension height control method provided by the aforementioned method embodiment, when executing the program stored in the memory 1013 .

[0059] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the road surface model reconstruction method provided by the aforementioned method embodiment is implemented, or the suspension height control method provided by the aforementioned method embodiment is implemented.

[0060] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0061] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a general hardware platform, and of course, by hardware. Based on this understanding, the above technical solution, in essence or in other words, the part that contributes to the relevant technology, can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiment.

[0062] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0063] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A road surface model reconstruction method, characterized in that: The method comprises: Acquiring vehicle status information, and obtaining tire track information and road surface information of the vehicle based on the vehicle status information; The tire track information and the road surface information are coordinate-fused to obtain the height information of the tire corresponding to the sampling point; A road surface model is acquired according to the height information of the tire at the sampling point, wherein the road surface model is used to fit the height information of the tire at the sampling point.

2. The road surface model reconstruction method according to claim 1, characterized in that: The step of fusing the tire track information and the road surface information to obtain tire height information corresponding to a sampling point includes: Fusing the tire track information with the road surface information, and projecting the tire track information onto the road surface information after the coordinate fusion to obtain projection track information of the tire; Based on the projection trajectory information, height information of the tire at the sampling point is obtained.

3. The road surface model reconstruction method according to claim 2, characterized in that: The step of acquiring the height information of the tire at the sampling point based on the projection trajectory information includes: Acquire tire width information, and obtain a tire footprint area based on the tire width information and the projection trajectory information, wherein the tire footprint area includes a plurality of tire footprint point sets, and the tire footprint point sets correspond one-to-one to the sampling points in the projection trajectory information; Based on the contact state between the tire and each point in the tire mark point set, the projection trajectory information corresponding to the sampling point is corrected, and based on the corrected projection trajectory information, the height information of the tire at the sampling point is obtained.

4. The road surface model reconstruction method according to claim 1, characterized in that: The step of obtaining a road surface model according to the tire height information at the sampling point includes: Dividing the tire track according to the height information of the tire at the sampling point to obtain a plurality of track segments, each of the plurality of track segments including a plurality of discrete sampling points; Selecting a preset number of sampling points from each of the plurality of trajectory segments for reconstruction to obtain a reconstruction curve of each trajectory segment, wherein the curvatures of the reconstruction curves of any two adjacent trajectory segments at the connection points are equal, and the connection points are the sampling points selected from the corresponding two trajectory segments; The road surface model is obtained based on the reconstructed curve of each trajectory segment.

5. The road surface model reconstruction method according to claim 1, characterized in that: The vehicle state information includes vehicle longitudinal speed, steering wheel angle, vehicle mass, vehicle front axle wheelbase, vehicle rear axle wheelbase, vehicle front wheel cornering stiffness, vehicle rear wheel cornering stiffness, vehicle inertia moment and road surface perception information; The obtaining of tire track information and road surface information of the vehicle based on the vehicle state information comprises: Based on the longitudinal speed of the vehicle, the steering wheel angle, the vehicle mass, the front axle wheelbase of the vehicle, the rear axle wheelbase of the vehicle, the front wheel cornering stiffness of the vehicle, the rear wheel cornering stiffness of the vehicle and the moment of inertia of the vehicle, the vehicle body trajectory information is calculated, and the vehicle body trajectory information is coordinate-converted to obtain the tire trajectory information, wherein the vehicle body trajectory information is used to characterize the heading angle and position coordinates of the vehicle at each time point in a preset time period in the future; Based on the road surface perception information, the road surface information is obtained.

6. A suspension height control method, characterized in that: The method comprises: The road surface model obtained by the road surface model reconstruction method according to any one of claims 1 to 5 is used to control the height of the suspension so that the chassis height changes with the height of the suspension.

7. A road surface model reconstruction device, characterized in that: The device comprises: A first acquisition module, used to acquire vehicle status information, and obtain tire track information and road surface information of the vehicle based on the vehicle status information; A coordinate fusion module, used to coordinately fuse the tire track information and the road surface information to obtain tire height information corresponding to a sampling point; The second acquisition module is used to acquire a road surface model according to the height information of the tire at the sampling point, wherein the road surface model is used to fit the height information of the tire at the sampling point.

8. A new energy vehicle, characterized in that: The new energy vehicles include: A vehicle sensing device, used to obtain vehicle status information; A road surface model reconstruction device, used to obtain tire track information and road surface information of the vehicle based on the vehicle state information; coordinately fuse the tire track information and the road surface information to obtain height information of the tire corresponding to the sampling point; and obtain a road surface model according to the height information of the tire at the sampling point, wherein the road surface model is used to fit the height information of the tire at the sampling point; The suspension control device is used to control the height of the suspension using the road surface model so that the chassis height changes following the height of the suspension.

9. An electronic device, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; Memory, used to store computer programs; The processor is used to implement the road surface model reconstruction method described in any one of claims 1 to 5, or the suspension height control method described in claim 6 when executing the program stored in the memory.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the road surface model reconstruction method described in any one of claims 1 to 5 or the suspension height control method described in claim 6 is implemented.

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