CN118205353A

CN118205353A - Height adjustment method and device for air suspension, electronic equipment and storage medium

Info

Publication number: CN118205353A
Application number: CN202410639455.1A
Authority: CN
Inventors: 周建波; 唐如意; 李杨; 苏星溢; 张操
Original assignee: Chengdu Seres Technology Co Ltd
Current assignee: Chengdu Seres Technology Co Ltd
Priority date: 2024-05-22
Filing date: 2024-05-22
Publication date: 2024-06-18

Abstract

The application relates to a height adjustment method and device of an air suspension, electronic equipment and a storage medium, wherein the method further comprises the following steps: acquiring a vector map corresponding to a vehicle navigation route, and generating a road surface elevation map and a target value map based on the vector map; according to the road surface elevation map and the target value map, determining a planning path of the vehicle and vehicle state information corresponding to each moment point when the vehicle runs along the planning path; planning the height from the road surface at the four-wheel chassis corresponding to each moment according to the vehicle state information corresponding to each moment; and adjusting the height of the air suspension corresponding to each moment of the vehicle according to the planning result. Therefore, the corresponding adjustment heights of the air suspension on the vehicle at different moments can be known in advance, advanced planning of the height adjustment of the air suspension is realized, and the problem that the existing height adjustment mode of the air suspension has a certain time lag when the height adjustment of the air suspension is carried out is effectively avoided.

Description

Height adjustment method and device for air suspension, electronic equipment and storage medium

Technical Field

The present application relates to the field of vehicle control technologies, and in particular, to a method and an apparatus for adjusting a height of an air suspension, an electronic device, and a storage medium.

Background

In the running process of a vehicle, the vehicle body is inclined due to uneven road or curve turning and the like, so that the running smoothness and comfort of the vehicle are poor, and in practical application, an air suspension is additionally arranged at the chassis position of four wheels of the vehicle to adjust the posture of the vehicle body, so that the running smoothness and comfort of the vehicle are improved.

However, in the conventional height adjustment method of the air suspension, after parameters such as a vehicle speed, a roll angle, a road surface condition and the like are collected, the collected parameters are used to determine the adjustment height of the air suspension, and then the air spring in the air suspension is subjected to inflation and deflation control according to the adjustment height of the air suspension, so that a certain time lag exists in the height adjustment of the air suspension by adopting the method. Therefore, how to plan the height adjustment value of the air suspension in advance becomes a technical problem to be solved.

Disclosure of Invention

The application provides a height adjusting method and device of an air suspension, electronic equipment and a storage medium, and aims to solve the problem that a certain time lag exists in the height adjusting mode of the air suspension when the height of the air suspension is adjusted.

In a first aspect, the present application provides a method for adjusting the height of an air suspension, the method comprising:

Acquiring a vector map corresponding to a vehicle navigation route, and generating a road surface elevation map and a target value map based on the vector map, wherein the road surface elevation map is determined based on road surface heights corresponding to different positions in the vector map, and the target value map is a value map obtained by comprehensively determining the type of an obstacle, the distribution position of the obstacle and the road surface height in the vector map;

Determining a planning path of the vehicle and vehicle state information corresponding to each moment point when the vehicle runs along the planning path according to the road surface elevation map and the target value map;

planning the height from the four-wheel chassis corresponding to each moment to the road surface according to the vehicle state information corresponding to each moment of the vehicle;

and adjusting the height of the air suspension corresponding to each moment of the vehicle according to the planning result.

Optionally, the planning the height of the vehicle from the road surface at the four-wheel chassis corresponding to each moment according to the vehicle state information corresponding to each moment of the vehicle includes:

Acquiring vehicle state information corresponding to the vehicle at the ith moment, wherein the vehicle state information comprises the height of a vehicle four-wheel chassis from a road surface, the rolling angle of the vehicle, the pitch angle of the vehicle and the maximum height of the road surface in a rectangular area of the road surface corresponding to the vehicle chassis, i is more than or equal to 0 and less than the total running time of the vehicle along a planned path;

determining a height combination set of the vehicle from the road surface at the four-wheel chassis corresponding to the (i+1) th moment according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the (i) th moment, and a preset maximum height variation of the air suspension and a preset minimum height variation of the air suspension;

Judging whether each height combination in the height combination set meets a preset constraint condition, wherein the preset constraint condition is used for constraining at least one of a height range from a four-wheel chassis at the i+1 moment to a road surface, a pitch angle variation of a vehicle from the i moment to the i+1 moment and a maximum height of the road surface in a rectangular area of the road surface corresponding to the vehicle chassis at the i+1 moment;

According to the judging result of each height combination in the height combination set, the height combination meeting the preset constraint condition in the height combination set is screened out, and the cost value of the height combination meeting the preset constraint condition is calculated by using a preset evaluation function, wherein the preset evaluation function is used for constraining the rolling angle of the vehicle at the i+1 moment;

and determining the height combination with the minimum cost value as the height combination of the vehicle from the road surface at the four-wheel chassis corresponding to the (i+1) th moment.

Optionally, the determining, according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the i time, the preset maximum height variation of the air suspension and the preset minimum height variation of the air suspension, the height combination set of the vehicle from the road surface at the four-wheel chassis corresponding to the i+1 time includes:

Respectively acquiring four sampling point sets corresponding to four wheels of the vehicle, wherein each sampling point set in the four sampling point sets comprises N sampling points, the N sampling points are obtained by sampling a preset search space according to a preset search step length, the preset search space is the distance between the maximum height variation of the air suspension and the minimum height variation of the air suspension, and N is an integer larger than 0;

Respectively selecting one sampling point from each of the four sampling point sets to be combined to obtain N ⁴ sampling point combinations;

And summing the height of the vehicle from the road surface at the four-wheel chassis corresponding to the i time with each sampling point combination in the N ⁴ sampling point combinations to obtain a height combination set of the vehicle from the road surface at the four-wheel chassis corresponding to the i+1 time, wherein the height combination set comprises N ⁴ height combinations, and each height combination in the N ⁴ height combinations corresponds to one sampling combination in the N ⁴ sampling point combinations.

Optionally, the preset constraint condition is expressed by the following formula:

；

Wherein, the method comprises the following steps of ,/>,/>,/>) Represents the j-th height combination in the height combination set, j is greater than 0 and less than or equal to N ⁴,/>Representing the height of the left front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the right front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the left rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the right rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the minimum height threshold of the chassis from the road surface after adding an air suspension,/>Representing the maximum height threshold of the chassis from the road surface after adding the air suspension,/>Representing the maximum variation threshold allowed by the pitch angle of the vehicle at two adjacent moments,/>Represents the pitch angle variation of the vehicle from the i-th time to the i+1-th time,/>，/>For calculating a pitch angle according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the ith moment and the air suspension height,/>For calculating a pitch angle according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the (i+1) th moment and the air suspension height,/>Represents the maximum height of the road surface in the rectangular area of the road surface corresponding to the chassis of the vehicle at the (i+1) th moment,/>Represents the road surface height corresponding to the left front wheel at the i+1 time,/>Represents the road surface height corresponding to the right front wheel at the i+1th moment,/>Represents the road surface height corresponding to the left rear wheel at the i+1 time,/>The road surface height corresponding to the right rear wheel at the i+1 time is shown.

Optionally, the preset evaluation function is expressed by the following formula:

；

Wherein, Representing an estimated cost of reaching a target node of the planned path from a starting node of the planned path,/>Representing the actual cost from the start node of the planned path to the corresponding node at time i +1,Representing the estimated cost of reaching the target node of the planned path from the corresponding node at time i +1, k being a weight value,Representing the corresponding rolling angle of the vehicle on the planned path at the (i+1) th moment,/>, andIn order to calculate the rolling angle according to the height of the vehicle from the road surface and the air suspension height at the four-wheel chassis corresponding to the (i+1) th moment, d is the axial length,/>Indicating the height of the left front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,Representing the height of the right front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the left rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the right rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Represents the road surface height corresponding to the left front wheel at the i+1 time,/>Represents the road surface height corresponding to the right front wheel at the i+1th moment,/>Represents the road surface height corresponding to the left rear wheel at the i+1 time,/>The road surface height corresponding to the right rear wheel at the i+1 time is shown.

Optionally, the determining, according to the road surface elevation map and the target value map, a planned path of the vehicle and vehicle state information corresponding to each moment point when the vehicle travels along the planned path includes:

Determining a planning path of the vehicle according to the target value map, wherein the planning path avoids a path obtained by a concave-convex area of a road surface as far as possible under the constraint condition of conforming to a preset traffic rule and vehicle movement;

Acquiring coordinate positions of four wheels of the vehicle in a target coordinate system at different moments and track curvature and running speed of the vehicle at different moments according to a planned path of the vehicle, wherein the target coordinate system is a coordinate system pre-constructed in the target value map;

according to the coordinate positions of the four wheels of the vehicle at different moments in the target coordinate system, determining the maximum height of the road surface in the rectangular road surface area corresponding to the vehicle chassis of the vehicle at different moments from the road surface elevation map;

determining the rolling angles of the vehicles at different moments according to the track curvature and the running speed of the vehicles at different moments;

and determining vehicle state information corresponding to each moment point when the vehicle runs along the planned path according to the maximum height of the road surface in the rectangular area of the road surface corresponding to the vehicle chassis of the vehicle at different moments and the rolling angle of the vehicle at different moment points.

Optionally, the coordinate positions of the four wheels of the vehicle in the target coordinate system are calculated using the following formula:

；

Wherein, Representing the abscissa of the left front wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the left front wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the left front wheel of the vehicle in the target coordinate system,Representing the ordinate of the left front wheel of the vehicle in the target coordinate system,/>Representing the abscissa of the right front wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the right front wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the right front wheel of the vehicle in the target coordinate system,/>Representing the ordinate of the right front wheel of the vehicle in the target coordinate system,/>Representing the abscissa of the left rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the left rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the left rear wheel of the vehicle in the target coordinate system,/>Representing the ordinate of the left rear wheel of the vehicle in the target coordinate system,/>Represents the abscissa of the right rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the right rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the right rear wheel of the vehicle in the target coordinate system,/>Representing the ordinate of the right rear wheel of the vehicle in the target coordinate system,/>Representing the abscissa of the centroid of the vehicle in the target coordinate system,/>Representing the ordinate of the centroid of the vehicle in the target coordinate system,/>Representing the roll angle of the centroid of the vehicle in the target coordinate system.

Optionally, the roll angle of the vehicle is calculated using the following formula:

；

Wherein, Representing gravitational acceleration,/>Representing the inverse of the curvature of the vehicle,/>Representing the travel speed of the vehicle.

Optionally, the obtaining a vector map corresponding to the navigation route of the vehicle, and generating a road surface elevation map and a target value map based on the vector map, includes:

Acquiring a vector map corresponding to a vehicle navigation route, wherein the vector map is a high-precision map or a real-time lane construction map;

Dividing the vector map into areas to obtain an initial value map, wherein the initial value map is used for representing the distance between the vehicle and the obstacle at different moments, and the grid value of each grid in the initial value map is determined by the type of the obstacle corresponding to the grid position and the distance between the grid and the obstacle;

performing road surface detection on the vector map to obtain the road surface elevation map, wherein the grid value of each grid in the road surface elevation map is determined by the road surface height corresponding to the grid position;

Dividing areas according to road surface height variables of adjacent grids in the road surface elevation map, wherein the road surface height variables are the same as the running direction of the vehicle, so as to obtain an intermediate value map, wherein the intermediate value map is used for representing the bumping condition of the vehicle at different moments, and the grid value of each grid in the intermediate value map is jointly determined by the road surface height variable corresponding to the grid position and a preset threshold value;

And merging the initial value map and the intermediate value map to obtain the target value map, wherein the grid value of each grid in the target value map is the maximum grid value of the corresponding grid in the initial value map and the corresponding grid in the intermediate value map.

In a second aspect, the present application also provides a height adjustment device for an air suspension, the device comprising:

The system comprises an acquisition module, a navigation module and a target value map, wherein the acquisition module is used for acquiring a vector map corresponding to a vehicle navigation route and generating a road surface elevation map and a target value map based on the vector map, the road surface elevation map is determined based on road surface heights corresponding to different positions in the vector map, and the target value map is a value map obtained by comprehensively determining the type of an obstacle, the distribution position of the obstacle and the road surface height in the vector map;

The determining module is used for determining a planning path of the vehicle and vehicle state information corresponding to each moment point when the vehicle runs along the planning path according to the road surface elevation map and the target value map;

The planning module is used for planning the height between the four-wheel chassis corresponding to each moment of the vehicle and the road surface according to the vehicle state information corresponding to each moment of the vehicle;

and the adjusting module is used for adjusting the height of the air suspension corresponding to each moment of the vehicle according to the planning result.

In a third aspect, the present application further provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, where the processor, the communication interface, and the memory complete communication with each other through the communication bus;

A memory for storing a computer program;

And the processor is used for realizing the height adjusting method of the air suspension according to any one of the first aspect when executing the program stored in the memory.

In a fourth aspect, the present application also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the height adjustment method of the air suspension of any one of the first aspects.

Compared with the prior art, the technical scheme provided by the application has the following advantages: according to the method provided by the application, a vector map corresponding to a vehicle navigation route is obtained, and a road surface elevation map and a target value map are generated based on the vector map, wherein the road surface elevation map is determined based on road surface heights corresponding to different positions in the vector map, and the target value map is a value map obtained by comprehensively determining the type of an obstacle, the distribution position of the obstacle and the road surface height in the vector map; determining a planning path of the vehicle and vehicle state information corresponding to each moment point when the vehicle runs along the planning path according to the road surface elevation map and the target value map; planning the height from the four-wheel chassis corresponding to each moment to the road surface according to the vehicle state information corresponding to each moment of the vehicle; and adjusting the height of the air suspension corresponding to each moment of the vehicle according to the planning result. By the method, the planning path of the vehicle and the vehicle state information corresponding to each moment point when the vehicle runs along the planning path can be obtained in advance, and then the height of the four-wheel chassis corresponding to each moment point of the vehicle from the road surface is planned according to the obtained vehicle state information in advance, so that the adjustment heights of the air suspensions on the vehicle at different moments can be obtained in advance, the advanced planning of the height adjustment of the air suspensions is realized, and the problem that the existing height adjustment mode of the air suspensions has a certain time lag when the height adjustment of the air suspensions is carried out is effectively avoided.

Drawings

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.

In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, and it will be obvious to a person skilled in the art that other drawings can be obtained from these drawings without inventive effort.

One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which the figures of the drawings are not to be taken in a limiting sense, unless otherwise indicated.

Fig. 1 is a schematic flow chart of a method for adjusting the height of an air suspension according to an embodiment of the present application;

fig. 2 is a schematic diagram of road surface heights corresponding to four wheels according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a stress analysis according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a road topology relationship in a vector map according to an embodiment of the present application;

FIG. 5 is a schematic diagram of an initial value map provided by an embodiment of the present application;

FIG. 6 is a schematic flow chart of a height adjustment method for an air suspension according to an embodiment of the present application;

Fig. 7 is a schematic structural diagram of a height adjusting device of an air suspension according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The following disclosure provides many different embodiments, or examples, for implementing different structures of the invention. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

In order to solve the problem that the existing height adjustment mode of the air suspension has a certain time lag when the height adjustment of the air suspension is carried out, the application provides a height adjustment method and device of the air suspension, electronic equipment and a storage medium, and the advanced planning of the height adjustment of the air suspension can be realized.

Referring to fig. 1, fig. 1 is a schematic flow chart of a method for adjusting the height of an air suspension according to an embodiment of the present application. As shown in fig. 1, the height adjusting method of the air suspension may include the steps of:

step 101, obtaining a vector map corresponding to a vehicle navigation route, and generating a road surface elevation map and a target value map based on the vector map, wherein the road surface elevation map is determined based on road surface heights corresponding to different positions in the vector map, and the target value map is a value map obtained based on comprehensive determination of obstacle types, obstacle distribution positions and road surface heights in the vector map.

Specifically, the vector map may be a commercial high-precision map or a real-time building map, and the vector map may include a topological relationship at a lane level and attributes of a plurality of map elements. The commercial high-precision map is different from a real-time constructed map in that: the precision of the real-time constructed map is lower than that of the commercial high-precision map, and the map elements of the real-time constructed map are fewer than those of the commercial high-precision map. The road surface elevation map is determined based on the road surface heights corresponding to different positions in the vector map, and the grid value of each grid in the road surface elevation map is a road surface height value, namely when the road surface height corresponding to a certain grid position is higher, the grid value is larger; when the road surface height corresponding to a certain grid position is low, the grid value is small. The target value map is a value map obtained by comprehensively determining the type of the obstacle, the distribution position of the obstacle and the road surface height in the vector map. The grid value of each grid in the target value map is determined by the type of the barrier at the grid position, the distance degree between the barrier and the road surface height, so that the target value map can be used for realizing the path planning of the vehicle and planning a track which meets the traffic rule and avoids the concave-convex road surface area as far as possible under the constraint condition of the vehicle kinematics.

And 102, determining a planned path of the vehicle and vehicle state information corresponding to each moment point when the vehicle runs along the planned path according to the road surface elevation map and the target value map.

Specifically, the above-mentioned vehicle state information includes, but is not limited to, information such as a height from the road surface at the vehicle four-wheel chassis, a roll angle of the vehicle, a pitch angle of the vehicle, and a maximum height of the road surface in a rectangular area of the road surface corresponding to the vehicle chassis.

In the step, a planned path of the vehicle can be determined firstly based on a target value map, a preset traffic rule, constraint conditions of vehicle kinematics and the like, and then vehicle state information corresponding to the vehicle at each moment can be determined according to the planned path of the vehicle.

And 103, planning the height from the road surface at the four-wheel chassis corresponding to each moment according to the vehicle state information corresponding to each moment.

In this step, after determining the vehicle state information corresponding to the vehicle at each time, the height of the vehicle from the road surface at the four-wheel chassis corresponding to each time can be planned according to the vehicle state information corresponding to the vehicle at each time, so as to obtain the height of the vehicle from the road surface at the four-wheel chassis corresponding to each time under the ideal state (with the air suspension at the optimal adjustment height).

And 104, adjusting the height of the air suspension corresponding to each moment of the vehicle according to the planning result.

In this step, the height of the air suspension of the vehicle at each time can be determined according to the height of the vehicle at the four-wheel chassis corresponding to each time from the road surface in an ideal state (the air suspension is at the optimal adjustment height) and the height of the vehicle at the four-wheel chassis corresponding to each time from the road surface in a non-ideal state (the air suspension is not introduced for height adjustment), and then the height of the air suspension is adjusted.

In this embodiment, the planned path of the vehicle and the vehicle state information corresponding to each time point when the vehicle runs along the planned path can be obtained in advance, and then the height of the four-wheel chassis corresponding to each time point of the vehicle from the road surface is planned according to the obtained vehicle state information in advance, so that the adjustment heights of the air suspensions on the vehicle corresponding to different time points can be obtained in advance, the advanced planning of the height adjustment of the air suspensions is realized, and the problem that the existing height adjustment mode of the air suspensions has a certain time lag when the height adjustment of the air suspensions is carried out is effectively avoided.

Further, the step 103 of planning the height of the vehicle from the road surface at the four-wheel chassis corresponding to each moment according to the vehicle state information corresponding to each moment, includes:

Acquiring vehicle state information corresponding to a vehicle at the ith moment, wherein the vehicle state information comprises the height of a vehicle four-wheel chassis from a road surface, the rolling angle of the vehicle, the pitch angle of the vehicle and the maximum height of the road surface in a rectangular area of the road surface corresponding to the vehicle chassis, and i is more than or equal to 0 and less than the total running time of the vehicle along a planned path;

determining a height combination set of the vehicle from the road surface at the four-wheel chassis corresponding to the (i+1) th moment according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the (i) th moment, the maximum height variation of the preset air suspension and the minimum height variation of the air suspension;

Judging whether each height combination in the height combination set meets a preset constraint condition, wherein the preset constraint condition is used for constraining at least one of a height range from the four-wheel chassis at the i+1 moment to a road surface, a pitch angle variation of a vehicle from the i moment to the i+1 moment and a maximum height of the road surface in a rectangular area of the road surface corresponding to the vehicle chassis at the i+1 moment;

According to the judging result of each height combination in the height combination set, screening out the height combinations meeting the preset constraint conditions in the height combination set, and respectively calculating the cost values of the height combinations meeting the preset constraint conditions by using a preset evaluation function, wherein the preset evaluation function is used for constraining the rolling angle of the vehicle at the i+1th moment;

When i is 0, the height from the road surface at the four-wheel chassis of the vehicle corresponding to the i-th moment can be understood as the height from the road surface at the four-wheel chassis of the vehicle acquired when the vehicle is at the starting position of the planned path. When i is greater than 0, the height from the road surface at the vehicle four-wheel chassis corresponding to the i-th moment can be understood as determining the height from the road surface at the vehicle four-wheel chassis according to the vehicle state information at the previous moment. The preset constraint condition may be used to constrain one or more of a range of heights from the road surface at the four-wheel chassis at the i+1 th moment, a pitch angle variation amount of the vehicle from the i moment to the i+1 th moment, and a maximum height of the road surface in a rectangular area of the road surface corresponding to the vehicle chassis at the i+1 th moment.

Specifically, the maximum height variation of the air suspension and the minimum height variation of the air suspension are manually preset based on the physical condition of the air suspension, and the height variation range of the air suspension can be limited. The preset evaluation function is used for evaluating the estimated cost of reaching the target node of the planning path from the starting node of the planning path, and the smaller the value is, the smaller the estimated cost of reaching the target node of the planning path from the starting node of the planning path is.

In an embodiment, when determining the height combination of the vehicle from the road surface at the four-wheel chassis corresponding to the i+1 time, vehicle state information corresponding to the vehicle at the previous time (i.e., the i time) such as the height of the vehicle from the road surface at the four-wheel chassis, the roll angle of the vehicle, the pitch angle of the vehicle, the maximum height of the road surface in the rectangular area of the road surface corresponding to the vehicle chassis, etc. can be obtained first, then according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the i+1 time, and the maximum height variation of the preset air suspension and the minimum height variation of the air suspension, determining a height combination set of the vehicle from the road surface at the four-wheel chassis corresponding to the i+1 time, then judging whether each height combination in the height combination set meets the preset constraint condition, screening the height combination meeting the preset constraint condition in the height combination set according to the judging result of each height combination set, and calculating the height combination meeting the preset constraint condition by using the preset evaluation function, and finally determining the height combination with the minimum cost value as the height combination of the road surface corresponding to the four-wheel chassis at the i+1 time. And the like, the determined height combination of the four-wheel chassis corresponding to the (i+1) th moment of the vehicle and the road surface can be utilized to determine the height combination of the four-wheel chassis corresponding to the (i+2) th moment of the vehicle and the road surface, so that the heights of the four-wheel chassis corresponding to different moments of the vehicle in the running process along the planned path can be obtained.

In the implementation, the constraint condition can be used for constraining at least one of the height range of the four-wheel chassis of the vehicle from the road surface, the pitch angle variation of the vehicle and the maximum height of the road surface in the rectangular area of the road surface corresponding to the vehicle chassis, so that an air suspension height adjustment scheme can be provided according to the physical condition constraint and the safe driving constraint of the air suspension, and drivers and passengers can have better experience and safety; and the rolling angle of the vehicle can be restrained by the preset evaluation function, the vehicle can be prevented from rolling over, the left and right shaking feeling of drivers is reduced, and the planned track is safer and more comfortable.

Further, the step of determining a height combination set of the vehicle from the road surface at the four-wheel chassis corresponding to the i+1 th moment according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the i th moment, and a preset maximum height variation of the air suspension and a preset minimum height variation of the air suspension, includes:

Respectively acquiring four sampling point sets corresponding to four wheels of a vehicle, wherein each sampling point set in the four sampling point sets comprises N sampling points, the N sampling points are obtained by sampling a preset search space according to a preset search step length, the preset search space is the distance between the maximum height variation of an air suspension and the minimum height variation of the air suspension, and N is an integer larger than 0;

And respectively carrying out summation calculation on the height of the vehicle from the road surface at the four-wheel chassis corresponding to the i time and each sampling point combination in N ⁴ sampling point combinations to obtain a height combination set of the vehicle from the road surface at the four-wheel chassis corresponding to the i+1 time, wherein the height combination set comprises N ⁴ height combinations, and each height combination in N ⁴ height combinations corresponds to one sampling combination in N ⁴ sampling point combinations.

In an embodiment, for any wheel on the vehicle, the distance between the maximum height variation of the air suspension and the minimum height variation of the air suspension may be sampled according to a preset search step, so as to obtain a set of sampling points corresponding to the wheel. The sampling point set corresponding to each wheel is assumed to comprise N sampling points, the sampling point sets corresponding to the four wheels are totally provided with N ⁴ sampling point combinations, and therefore the height of the vehicle from the road surface at the four-wheel chassis corresponding to the ith moment is summed with each sampling point combination in the N ⁴ sampling point combinations, and a height combination set comprising N ⁴ height combinations can be obtained.

For ease of understanding, the left front wheel of the vehicle will be described herein as an example. For example, assume that the maximum height variation of the air suspension is usedThe minimum height variation of the air suspension is expressed as/>Representing that the sampling point set corresponding to the i-th moment of the left front wheel can be used/>Representation, where/>There are N sampling points in (c). Similarly, a sampling point set/>, corresponding to the i-th moment, of the right front wheel of the vehicle can be obtainedSampling point set/>, corresponding to the i-th moment, of the left rear wheel of the vehicleSampling point set/>, corresponding to the i-th moment of the right rear wheel of the vehicle. When one sampling point is randomly selected from the four sampling point sets to calculate, a height combination corresponding to four wheels of the vehicle can be obtained, and the height combination can be expressed by adopting the following formula:

；

Wherein, the method comprises the following steps of ,/>,/>,/>) Represents the j-th height combination in the height combination set, j is greater than 0 and less than or equal to N ⁴,/>Indicating the height of the left front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,Representing the height of the right front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the left rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the right rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the minimum height threshold of the chassis from the road surface after adding an air suspension,/>Representing the height of the chassis of the left front wheel from the road surface at the ith moment,/>Representing the height of the right front wheel chassis from the road surface at the ith moment,/>Representing the height of the chassis of the left rear wheel from the road surface at the ith moment,/>Representing the height of the right rear wheel chassis from the road surface at the ith moment,/>Represents the j-th sampling point in the sampling point set corresponding to the left front wheel,/>Represents the j-th sampling point in the sampling point set corresponding to the right front wheel,/>Represents the j-th sampling point in the sampling point set corresponding to the left rear wheel,/>And represents the j-th sampling point in the sampling point set corresponding to the rear right wheel.

In this embodiment, the distance between the maximum height variation of the air suspension and the minimum height variation of the air suspension may be sampled to obtain a plurality of sampling combinations, so as to obtain all possible height combinations of the vehicle from the road surface at the four-wheel chassis at the next moment, so that the vehicle can conveniently traverse all possible height combinations, and find the optimal height combination as the height of the vehicle from the road surface at the four-wheel chassis at the next moment.

Further, the preset constraint condition is expressed by the following formula:

；

Wherein, the method comprises the following steps of ,/>,/>,/>) Represents the j-th height combination in the height combination set, j is greater than 0 and less than or equal to N ⁴,/>Indicating the height of the left front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,Representing the height of the right front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the left rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the right rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the minimum height threshold of the chassis from the road surface after adding an air suspension,/>Representing the maximum height threshold of the chassis from the road surface after adding the air suspension,/>Representing the maximum variation threshold allowed by the pitch angle of the vehicle at two adjacent moments,/>Represents the pitch angle variation of the vehicle from the i-th time to the i+1-th time,，/>In order to calculate the pitch angle according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the ith moment and the air suspension height,For calculating the pitch angle according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the (i+1) th moment and the air suspension height,/>Represents the maximum height of the road surface in the rectangular area of the road surface corresponding to the chassis of the vehicle at the (i+1) th moment,/>Represents the road surface height corresponding to the left front wheel at the i+1 time,/>Represents the road surface height corresponding to the right front wheel at the i+1th moment,/>Represents the road surface height corresponding to the left rear wheel at the i+1 time,/>The road surface height corresponding to the right rear wheel at the i+1 time is shown.

Specifically, the above、/>And/>The setting may be performed according to actual situations, and is not particularly limited in the embodiment of the present application. /(I)Wherein, l is the distance between axes,A function is calculated for the pitch angle. /(I)

In an embodiment, the constraint condition may be used to simultaneously constrain a height range from the road surface at the four-wheel chassis at the i+1 th moment, a pitch angle variation amount of the vehicle from the i moment to the i+1 th moment, and a maximum height of the road surface in a rectangular area of the road surface corresponding to the vehicle chassis at the i+1 th moment. In particular, the method comprises the steps of,The height from the road surface at the (i+1) th moment is in a specified height range for restraining the left front wheel chassis. /(I)The height from the road surface at the (i+1) th moment is in a specified height range for restraining the right front wheel chassis. /(I)The height from the road surface at the (i+1) th moment is in a specified height range for restraining the left rear wheel chassis. /(I)The height from the road surface at the (i+1) th moment is in a specified height range for restraining the right rear wheel chassis. Therefore, the vehicle can run in a smaller fluctuation range, and the excessive inclination of the vehicle is avoided. /(I)For restraining the pitch angle variation of the vehicle from the i-th time to the i+1-th time within a specified range, so that discomfort to the driver caused by pitching of the vehicle can be avoided.The maximum height of the road surface in the rectangular area of the road surface corresponding to the vehicle chassis at the i+1 moment is constrained to be smaller than the minimum value of the sum of the height of each wheel chassis in the four wheels from the road surface and the height of the bottom surface corresponding to each wheel position, so that the vehicle chassis can be prevented from scraping the road surface.

In the implementation, the constraint condition can simultaneously constrain the height range of the four-wheel chassis of the vehicle from the road surface, the pitch angle variation of the vehicle and the maximum height of the road surface in the rectangular road surface area corresponding to the vehicle chassis, so that an air suspension height adjustment scheme can be provided according to the physical condition constraint and the safe driving constraint of the air suspension, and a driver and a passenger can have better experience and safety.

Further, the preset evaluation function is expressed by the following formula:

；

Wherein, Representing an estimated cost of reaching a target node of the planned path from a starting node of the planned path,Representing the actual cost of the corresponding node from the starting node to the i+1th moment of the planned path,/>Representing estimated cost of reaching a target node of a planned path from a corresponding node at time i+1, k being a weight value,/>Representing corresponding rolling angle of vehicle on planned path at i+1th moment,/>In order to calculate the rolling angle according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the (i+1) th moment and the air suspension height, d is the axial length,/>Representing the height of the left front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the right front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the left rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Indicating the height of the right rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,Represents the road surface height corresponding to the left front wheel at the i+1 time,/>Represents the road surface height corresponding to the right front wheel at the i+1 moment,Represents the road surface height corresponding to the left rear wheel at the i+1 time,/>The road surface height corresponding to the right rear wheel at the i+1 time is shown.

In one embodiment, each height combination that satisfies the preset constraint may be evaluated using the above formula. As can be seen from the above formula, due to the cost valueThe smaller and better, i.e. the need/>The smaller and better the value of (c) and thus the need/>The closer/>. That is, the roll angle obtained after the height adjustment of the air suspension is required to be as close as possible to the roll angle of the vehicle at the i+1th moment, so that the cost value can be obtainedThe vehicle rollover angle can be restrained by the preset evaluation function, rollover of the vehicle can be prevented, the left and right shaking feeling of drivers is reduced, and the planned track is safer and more comfortable.

Further, the step 102 of determining the planned path of the vehicle and the vehicle state information corresponding to each time point when the vehicle travels along the planned path according to the road surface elevation map and the target value map includes:

determining a planning path of the vehicle according to the target value map, wherein the planning path avoids the path obtained by the concave-convex area of the road surface as much as possible under the constraint condition of conforming to the preset traffic rule and the vehicle movement;

According to the planned path of the vehicle, coordinate positions of four wheels of the vehicle at different moments in a target coordinate system and track curvature and running speed of the vehicle at different moments are obtained, wherein the target coordinate system is a coordinate system pre-constructed in a target value map;

according to the coordinate positions of four wheels of the vehicle at different moments in a target coordinate system, determining the maximum height of the road surface in a rectangular area of the road surface corresponding to the vehicle chassis of the vehicle at different moments in a road surface elevation chart;

and determining the maximum height of the road surface in the rectangular area of the road surface corresponding to the vehicle chassis of the vehicle at different moments and the rolling angle of the vehicle at different moments as vehicle state information corresponding to each moment when the vehicle runs along the planned path.

Specifically, according to the preset constraint condition and the formula of the preset evaluation function, it is necessary to obtain the maximum height of the road surface in the rectangular area of the road surface corresponding to the vehicle chassis at the i+1 time in advanceAnd the corresponding rolling angle/>, on the planned path, of the vehicle at the (i+1) th momentProcessing analysis can be performed by using preset constraint conditions and preset evaluation functions. That is, it is necessary to acquire in advance the maximum height of the road surface in the rectangular area of the road surface corresponding to the chassis of the vehicle at each time and the roll angle corresponding to the vehicle at each time on the planned path.

In an embodiment, a planned path of the vehicle may be determined according to the target value map, where the planned path avoids a path obtained by the concave-convex area of the road surface as much as possible under the constraint condition that the planned path conforms to a preset traffic rule and the motion of the vehicle. And then, according to the planned path of the vehicle, acquiring the coordinate positions of the four wheels of the vehicle at different moments in a target coordinate system, and further, according to the coordinate positions of the four wheels of the vehicle at different moments in the target coordinate system, determining the maximum height of the road surface in the rectangular area of the road surface corresponding to the vehicle chassis of the vehicle at different moments from the road surface elevation map. For example, according to the coordinate positions of the four wheels of the vehicle at the i-th moment in the target coordinate system, the road surface heights corresponding to the four wheels can be obtained in the elevation chart. As shown in fig. 2, it can be seen from fig. 2 that the rear wheel is a waveform in which the front wheel delays for a period of time, and the specific delay time is determined by the speed of the current time, and the maximum height of the road surface in the rectangular area of the road surface corresponding to the vehicle chassis at each moment can be obtained in the elevation chart.

Meanwhile, the track curvature and the running speed of the vehicles at different moments can be obtained according to the planned path of the vehicle, and then the rolling angles of the vehicles at different moments are determined according to the track curvature and the running speed of the vehicles at different moments. Of course, other state information such as the pitch angle, the speed, the running position, the road surface height of the running position and the like of the vehicle can be obtained according to the planned path of the vehicle.

By the method, the vehicle state information corresponding to each moment point when the vehicle runs along the planned path can be accurately obtained, and the following planning of the height of the vehicle from the road surface at the four-wheel chassis corresponding to each moment point is facilitated according to the vehicle state information corresponding to each moment point.

Further, the coordinate positions of the four wheels of the vehicle in the target coordinate system are calculated using the following formula:

；

Wherein, Representing the abscissa of the left front wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the left front wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the left front wheel of the vehicle in the target coordinate system,/>Representing the ordinate of the left front wheel of the vehicle in the target coordinate system,/>Representing the abscissa of the right front wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the right front wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the right front wheel of the vehicle in the target coordinate system,/>Representing the ordinate of the right front wheel of the vehicle in the target coordinate system,/>Representing the abscissa of the left rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the left rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the left rear wheel of the vehicle in the target coordinate system,/>Representing the ordinate of the left rear wheel of the vehicle in the target coordinate system,/>Representing the abscissa of the right rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the right rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the right rear wheel of the vehicle in the target coordinate system,/>Representing the ordinate of the right rear wheel of the vehicle in the target coordinate system,/>Representing the abscissa of the centroid of the vehicle in the target coordinate system,/>Representing the ordinate of the centroid of the vehicle in the target coordinate system,/>Representing the roll angle of the centroid of the vehicle in the target coordinate system.

In one embodiment, a vehicle coordinate system may be established, and then the positions of the four wheels of the vehicle on the vehicle coordinate system may be set according to the vehicle parameters, respectively. Traversing the planned path point under the target coordinate system, and when the centroid of the vehicle is in the pose/>, of the path pointIn this case, the above formula can be used to obtain the coordinate positions of the four wheels of the vehicle in the target coordinate system, which are/>, respectively。

Through the method, the coordinate positions of the four wheels of the vehicle at each moment in the target coordinate system can be obtained, and the maximum height of the road surface in the rectangular road surface area corresponding to the vehicle chassis at each moment can be conveniently and subsequently determined in the road surface elevation chart according to the position index.

Further, the roll angle of the vehicle is calculated using the following formula:

；

Wherein, Representing gravitational acceleration,/>Representing the reciprocal of the curvature of the vehicle,/>Indicating the running speed of the vehicle.

In one embodiment, the roll angle of the vehicle may be obtained according to the above formula. Specifically, the derivation process of the formula is as follows:

first, the centripetal force acceleration is known from the vehicle kinematics Where v is the running speed of the vehicle and 1/r is the curvature of the vehicle. And, after determining the planned path of the vehicle according to the objective cost function, the curvature corresponding to the planned path at different times may be calculated by a difference method, specifically, for points P0 (x 0, y 0), P1 (x 1, y 1) and P2 (x 2, y 2), the vector difference may be expressed as Δp0=p1-p0= (x 1-x0, y1-y 0), Δp1=p2-p1= (x 2-x1, y2-y 1), the angle of the two vector differences is calculated by the point and the module length, the included angle is converted into radian, and then divided by the distance between adjacent points, so as to obtain the approximate value of the curvature.

Then, in order to improve the comfort of the person in the vehicle, the body is perpendicular to the plane of the seat, and the gravity, the seat supporting force and the centripetal force are subjected to stress analysis, wherein the component in the x direction of the seat supporting force is the centripetal force, the component in the y direction of the seat supporting force is the gravity, and the included angle between the supporting force and the centripetal force is shown in fig. 3，/>; Thereby can be obtained。

From the stress analysis of fig. 3, it can be further known that the planned chassis plane is obtained after the air suspension needs to be adjusted, and the height of the left air suspension needs to be adjusted when the vehicle turns around a curve isThe right air suspension needs to be adjusted to have the height ofWherein d is the vehicle axial length,/>Is the angle between the centripetal force and the chassis plane.

By the method, the corresponding rolling angles of the vehicles on the planned path at all times can be obtained, and the subsequent evaluation of all the height combinations according to the corresponding rolling angles of the vehicles on the planned path at all the times is facilitated.

Further, the step 101 of obtaining a vector map corresponding to the navigation route of the vehicle and generating a road surface elevation map and a target value map based on the vector map includes:

dividing the vector map into areas to obtain an initial value map, wherein the initial value map is used for representing the distance between the vehicle and the obstacle at different moments, and the grid value of each grid in the initial value map is determined by the type of the obstacle corresponding to the grid position and the distance between the obstacle and the vehicle;

Detecting the road surface of the vector map to obtain a road surface elevation map, wherein the grid value of each grid in the road surface elevation map is determined by the road surface height corresponding to the grid position;

Dividing areas according to road surface height variables of adjacent grids in the same running direction of the vehicle in the road surface elevation map to obtain an intermediate value map, wherein the intermediate value map is used for representing the bumping situation of the vehicle at different moments, and the grid value of each grid in the intermediate value map is jointly determined by the road surface height variable corresponding to the grid position and a preset threshold value;

And merging the initial value map and the intermediate value map to obtain a target value map, wherein the grid value of each grid in the target value map is the maximum grid value of the corresponding grid in the initial value map and the corresponding grid in the intermediate value map.

In an embodiment, a vector map corresponding to a navigation route of a vehicle, such as a high-precision map or a real-time lane building map, may be obtained first, and then the vector map is divided into regions to obtain an initial value map. As an alternative embodiment, the vector map may be divided into five drivable regions according to traffic rules and road driving hazard levels, wherein the first drivable region may be a drivable region with a higher hazard level in regions allowed to be driven by the traffic rules, for example, regions including guardrails, trees, bars, sidewalks with a road edge higher than a preset threshold, and the like. The second travelable region may be a region that can be borrowed by a special situation but cannot be occupied for a long period of time, such as a reverse lane, an intersection region, an emergency lane, a solid line portion of a lane that does not lead to a destination, a single solid line, a sidewalk with a road edge below a preset threshold, or the like. The third travelable region may be a region that needs to be travelable when certain conditions specified by the traffic regulations are met, such as a sidewalk, a waiting area, a stop line, etc. The fourth drivable region may be a region which normally does not need to be occupied, for example, a lane broken line, and the vehicle should be kept as straight as possible during normal driving, so that a merging operation is not required by occupying the lane broken line. The fifth drivable region may be a permitted driving region, and the fifth drivable region is a drivable region of the host vehicle according to a communication relationship between the navigation route and the lane, for example, the host vehicle is required to turn right at the intersection according to the navigation route, and the host vehicle cannot turn right or cannot change lanes and is not included. Wherein, the grid value of the grid corresponding to the first travelable region > the grid value of the grid corresponding to the second travelable region > the grid value of the grid corresponding to the third travelable region > the grid value of the grid corresponding to the fourth travelable region > the grid value of the grid corresponding to the fifth travelable region. Specifically, it is possible to set the grid value in the first drivable region to 4, the grid value in the second drivable region to 3, the grid value in the third drivable region to 2, the grid value in the fourth drivable region to 1, and the grid value in the fifth drivable region to a value greater than 0 and less than 1. The closer the grid value in the fifth drivable region is to 0, the closer the region in which the grid is located is to the lane center line. For example, assuming that the topological relation of the roads in the vector map is shown in fig. 4, after the vector map is divided into areas, an initial value map as shown in fig. 5 can be obtained.

And, the vector map can be subjected to road surface detection to obtain a road surface elevation map. Specifically, a network model occupied by a road boundary or a special-shaped barrier network model can be intercepted to obtain a three-dimensional voxel map in a road, then a grid map is established on an x-y plane in a vehicle coordinate system, the grid size is consistent with an initial value map, the grid median is the maximum value of z-axis voxels, and a two-dimensional road surface elevation map is generated; the road surface detection model can also be utilized to generate a two-dimensional road surface elevation map. After the two-dimensional road surface elevation map is generated, the area division can be performed according to the road surface elevation variable of the adjacent grid, which is the same as the running direction of the vehicle, in the road surface elevation map, so as to obtain the intermediate value map. Specifically, when the absolute value of the altitude change amount on the road surface elevation map is higher than a preset threshold value (such as 0.3, etc.), the grid area is set as a first area, otherwise, the grid area is set as a fifth area, and different values are set in the fifth area according to the absolute value of the altitude change amount. For example, parabolic functions may be utilizedAnd calculating, wherein k is a preset coefficient, such as 10, x represents a road surface height variable corresponding to the grid position, and y represents a grid value corresponding to the grid position.

After the initial value map and the intermediate value map are acquired, the initial value map and the intermediate value map can be combined to obtain the target value map. Specifically, the maximum grid value of the grids with the same serial numbers as the initial value map and the intermediate value map is taken and combined into the target value map.

In the embodiment, a time prediction value map representing the distance degree between the vehicle and the obstacle and the road surface height change degree can be generated, and traffic rule constraint and lane topological relation constraint are considered, so that the path optimization process is more in line with the actual situation, meanwhile, the road surface concave-convex area is avoided as far as possible, and more comfortable experience can be brought to users.

In an embodiment, as shown in fig. 6, the height adjustment flow of the air suspension provided by the embodiment of the application may be that the vehicle includes a map module, a track prediction module, a decision module, a chassis data acquisition module, and a road plane detection module. Firstly, map information can be subjected to regional division through a map module to generate a first value map (namely the initial value map), a road plane detection module is utilized to detect a road plane to obtain an elevation map, then, the elevation map is subjected to regional division to obtain a second value map (namely the intermediate value map), and the first value map and the second value map are combined to obtain a third value map. And then, carrying out track prediction on the third value map by utilizing a track prediction module to generate a value map time sequence. And then, planning a smooth track by utilizing a decision signal in the decision module, then, planning a vehicle side-tipping angle by utilizing a vehicle attitude angle in the chassis data acquisition module, and finally, planning the air suspension height of the concave-convex road section by utilizing the planned vehicle side-tipping angle and an elevation map.

Therefore, the planned track can avoid the concave-convex area as far as possible under the condition of conforming to traffic rules and vehicle kinematics constraint, so that the vibration of drivers and passengers is reduced, and better experience is realized; in addition, the planned track contains a rolling angle, so that the vehicle is prevented from rolling over, the left and right shaking feeling of drivers is reduced, and the planned track is safer and more comfortable; in addition, the planned track provides an air suspension height adjustment scheme in the physical condition constraint and the safety constraint of the air suspension on the undulating concave-convex road section, so that drivers and passengers can experience better and safety.

Referring to fig. 7, fig. 7 is a schematic structural diagram of a height adjusting device of an air suspension according to an embodiment of the present application. As shown in fig. 7, the height adjusting apparatus 700 of the air suspension includes:

The obtaining module 701 is configured to obtain a vector map corresponding to a vehicle navigation route, and generate a road surface elevation map and a target value map based on the vector map, where the road surface elevation map is determined based on road surface heights corresponding to different positions in the vector map, and the target value map is a value map determined comprehensively based on an obstacle type, an obstacle distribution position and the road surface heights in the vector map;

the determining module 702 is configured to determine, according to the road surface elevation map and the target value map, a planned path of the vehicle and vehicle state information corresponding to each moment when the vehicle travels along the planned path;

a determining module 703, configured to plan a height from the road surface at the four-wheel chassis corresponding to each moment according to the vehicle state information corresponding to each moment of the vehicle;

and the adjusting module 704 is used for adjusting the height of the air suspension corresponding to each moment of the vehicle according to the planning result.

Further, the determining module 703 includes:

The first acquisition submodule is used for acquiring vehicle state information corresponding to the vehicle at the ith moment, wherein the vehicle state information comprises the height of the vehicle from the road surface at the four-wheel chassis, the rolling angle of the vehicle, the pitch angle of the vehicle and the maximum height of the road surface in a rectangular area of the road surface corresponding to the vehicle chassis, i is more than or equal to 0 and is less than the total running time of the vehicle along a planned path;

The first determining submodule is used for determining a height combination set of the vehicle at the position of the four-wheel chassis corresponding to the (i+1) th moment from the road surface according to the height of the vehicle at the position of the four-wheel chassis corresponding to the (i) th moment from the road surface, and a preset maximum height variation of the air suspension and a preset minimum height variation of the air suspension;

The judging submodule is used for judging whether each height combination in the height combination set meets a preset constraint condition or not, wherein the preset constraint condition is used for constraining at least one of a height range from the four-wheel chassis at the i+1 moment to a road surface, a pitch angle variation of a vehicle from the i moment to the i+1 moment and a maximum height of the road surface in a rectangular area of the road surface corresponding to the vehicle chassis at the i+1 moment;

The screening submodule is used for screening out the height combinations meeting the preset constraint conditions in the height combination set according to the judging result of each height combination in the height combination set, and calculating the cost values of the height combinations meeting the preset constraint conditions by using preset evaluation functions, wherein the preset evaluation functions are used for constraining the rolling angle of the vehicle at the i+1th moment;

and the second determining submodule is used for determining the height combination with the minimum cost value as the height combination of the vehicle from the road surface at the four-wheel chassis corresponding to the (i+1) th moment.

Further, the first determining submodule includes:

the acquisition unit is used for respectively acquiring four sampling point sets corresponding to four wheels of the vehicle, wherein each sampling point set in the four sampling point sets comprises N sampling points, the N sampling points are obtained by sampling a preset search space according to a preset search step length, the preset search space is the distance between the maximum height variation of the air suspension and the minimum height variation of the air suspension, and N is an integer larger than 0;

the combination unit is used for respectively selecting one sampling point from each of the four sampling point sets to be combined to obtain N ⁴ sampling point combinations;

The computing unit is used for carrying out summation computation on the height of the vehicle from the road surface at the four-wheel chassis corresponding to the i time and each sampling point combination in N ⁴ sampling point combinations to obtain a height combination set of the vehicle from the road surface at the four-wheel chassis corresponding to the i+1 time, wherein the height combination set comprises N ⁴ height combinations, and each height combination in N ⁴ height combinations corresponds to one sampling combination in N ⁴ sampling point combinations.

Further, the preset constraint condition is expressed by the following formula:

；

Further, the preset evaluation function is expressed by the following formula:

；

Further, the determining module 702 includes:

the third determining submodule is used for determining a planning path of the vehicle according to the target value map, wherein the planning path avoids the path obtained by the concave-convex area of the road surface as far as possible under the constraint condition of conforming to the preset traffic rule and the vehicle movement;

the second acquisition sub-module is used for acquiring coordinate positions of four wheels of the vehicle at different moments in a target coordinate system according to a planning path of the vehicle, and track curvature and running speed of the vehicle at different moments, wherein the target coordinate system is a coordinate system pre-constructed in a target value map;

a fourth determining submodule, configured to determine, according to coordinate positions of four wheels of the vehicle at different times in the target coordinate system, maximum heights of the road surface in the rectangular area of the road surface corresponding to the vehicle chassis of the vehicle at different times from the road surface elevation map;

A fifth determining submodule for determining the rolling angle of the vehicle at different moments according to the track curvature and the running speed of the vehicle at different moments;

And the sixth determining submodule is used for determining vehicle state information corresponding to each moment point when the vehicle runs along the planned path according to the maximum height of the road surface in the rectangular area of the road surface corresponding to the vehicle chassis of the vehicle at different moments and the rolling angles of the vehicle at different moments.

；

Further, the acquired module 701 includes:

The third acquisition sub-module is used for acquiring a vector map corresponding to the vehicle navigation route, wherein the vector map is a high-precision map or a real-time lane construction map;

the first dividing sub-module is used for dividing the vector map into areas to obtain an initial value map, wherein the initial value map is used for representing the distance between the vehicle and the obstacle at different moments, and the grid value of each grid in the initial value map is determined by the type of the obstacle corresponding to the grid position and the distance between the vehicle and the obstacle;

The detection submodule is used for detecting the road surface of the vector map to obtain a road surface elevation map, wherein the grid value of each grid in the road surface elevation map is determined by the road surface height corresponding to the grid position;

The second dividing sub-module is used for dividing areas according to road surface height variables of adjacent grids in the road surface elevation graph, wherein the road surface height variables are the same as the running direction of the vehicle, so that an intermediate value map is obtained, the intermediate value map is used for representing the bumping condition of the vehicle at different moments, and the grid value of each grid in the intermediate value map is determined jointly by the road surface height variable corresponding to the grid position and a preset threshold value;

And the merging sub-module is used for merging the initial value map and the intermediate value map to obtain a target value map, wherein the grid value of each grid in the target value map is the maximum grid value of the corresponding grid in the initial value map and the corresponding grid in the intermediate value map.

It should be noted that, the device 700 may implement the height adjustment method of the air suspension provided in any of the foregoing method embodiments, and may achieve the same technical effects, which will not be described in detail herein.

As shown in fig. 8, the embodiment of the present application further provides an electronic device, which includes a processor 811, a communication interface 812, a memory 813, and a communication bus 814, wherein the processor 811, the communication interface 812, the memory 813 complete communication with each other through the communication bus 814,

A memory 813 for storing a computer program;

In one embodiment of the present application, the processor 811 is configured to implement the method for adjusting the height of the air suspension provided in any of the foregoing method embodiments when executing the program stored in the memory 813.

The embodiment of the application also provides a computer readable storage medium, and a computer program is stored on the computer readable storage medium, and when the computer program is executed by a processor, the height adjusting method of the air suspension provided by any one of the method embodiments is realized.

The apparatus embodiments described above are merely illustrative, wherein the elements illustrated as separate elements may or may not be physically separate, and the elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

From the above description of embodiments, it will be apparent to those skilled in the art that the embodiments may be implemented by means of software plus a general purpose hardware platform, or may be implemented by hardware. Based on such understanding, the foregoing technical solution may be embodied essentially or in a part contributing to the related art in the form of a software product, which may be stored in a computer readable storage medium, such as ROM/RAM, a magnetic disk, an optical disk, etc., including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the method described in the respective embodiments or some parts of the embodiments.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless an order of performance is explicitly stated. It should also be appreciated that additional or alternative steps may be used.

The foregoing is only a specific embodiment of the invention to enable those skilled in the art to understand or practice the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of height adjustment of an air suspension, the method comprising:

2. The method according to claim 1, wherein the planning the height of the vehicle from the road surface at the four-wheel chassis corresponding to each moment according to the vehicle state information corresponding to each moment of the vehicle comprises:

3. The method according to claim 2, wherein the determining the combined set of the heights of the vehicle from the road surface at the four-wheel chassis corresponding to the i+1 th moment according to the heights of the vehicle from the road surface at the four-wheel chassis corresponding to the i th moment, and the preset maximum height variation of the air suspension and the preset minimum height variation of the air suspension comprises:

4. The method of claim 2, wherein the predetermined constraint is expressed by the following formula:

；

Wherein, the method comprises the following steps of , />, />, />) Represents the j-th height combination in the height combination set, j is greater than 0 and less than or equal to N ⁴,/>Representing the height of the left front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Indicating the height of the right front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,Representing the height of the left rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the right rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the minimum height threshold of the chassis from the road surface after adding an air suspension,/>Representing the maximum height threshold of the chassis from the road surface after incorporation of the air suspension,Representing the maximum variation threshold allowed by the pitch angle of the vehicle at two adjacent moments,/>Represents the pitch angle variation of the vehicle from the i-th time to the i+1-th time,/>，For calculating a pitch angle according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the ith moment and the air suspension height,/>For calculating a pitch angle according to the height of the vehicle from the road surface at the four-wheel chassis corresponding to the (i+1) th moment and the air suspension height,/>Represents the maximum height of the road surface in the rectangular area of the road surface corresponding to the chassis of the vehicle at the (i+1) th moment,/>Represents the road surface height corresponding to the left front wheel at the i+1 time,/>Represents the road surface height corresponding to the right front wheel at the i+1th moment,/>Represents the road surface height corresponding to the left rear wheel at the i+1 time,/>The road surface height corresponding to the right rear wheel at the i+1 time is shown.

5. The method of claim 4, wherein the predetermined evaluation function is expressed using the following formula:

；

Wherein, Representing an estimated cost of reaching a target node of the planned path from a starting node of the planned path,/>Representing the actual cost from the starting node of the planned path to the corresponding node at time i+1,/>Representing estimated cost of arrival at a target node of the planned path from a corresponding node at time i+1, k being a weight value,/>Representing the corresponding rolling angle of the vehicle on the planned path at the (i+1) th moment,/>, andIn order to calculate the rolling angle according to the height of the vehicle from the road surface and the air suspension height at the four-wheel chassis corresponding to the (i+1) th moment, d is the axial length,/>Representing the height of the left front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the right front wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the left rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Representing the height of the right rear wheel chassis from the road surface at the (i+1) th moment in the j-th height combination,/>Represents the road surface height corresponding to the left front wheel at the (i+1) th moment,Represents the road surface height corresponding to the right front wheel at the i+1th moment,/>Represents the road surface height corresponding to the left rear wheel at the (i+1) th moment,The road surface height corresponding to the right rear wheel at the i+1 time is shown.

6. The method according to claim 1, wherein determining a planned path of the vehicle and vehicle state information corresponding to each point in time when the vehicle travels along the planned path according to the road surface elevation map and the target value map includes:

7. The method of claim 6, wherein the coordinate positions of the four wheels of the vehicle in the target coordinate system are calculated using the following formula:

；

Wherein, Representing the abscissa of the left front wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the left front wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the left front wheel of the vehicle in the target coordinate system,/>Representing the ordinate of the left front wheel of the vehicle in the target coordinate system,/>Representing the abscissa of the right front wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the right front wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the right front wheel of the vehicle in the target coordinate system,/>Representing the ordinate of the right front wheel of the vehicle in the target coordinate system,/>Representing the abscissa of the left rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the left rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the left rear wheel of the vehicle in the target coordinate system,/>Representing the ordinate of the left rear wheel of the vehicle in the target coordinate system,/>Represents the abscissa of the right rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the ordinate of the right rear wheel of the vehicle in the own vehicle coordinate system,/>Representing the abscissa of the right rear wheel of the vehicle in the target coordinate system,/>Representing the ordinate of the right rear wheel of the vehicle in the target coordinate system,/>Representing the abscissa of the centroid of the vehicle in the target coordinate system,/>Representing the ordinate of the centroid of the vehicle in the target coordinate system,/>Representing the roll angle of the centroid of the vehicle in the target coordinate system.

8. The method of claim 6, wherein the roll angle of the vehicle is calculated using the formula:

；

9. The method of claim 1, wherein the obtaining a vector map corresponding to a vehicle navigation route and generating a road surface elevation map and a target value map based on the vector map comprises:

10. A height adjustment device for an air suspension, the device comprising:

11. The electronic equipment is characterized by comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are communicated with each other through the communication bus;

A memory for storing a computer program;

a processor for implementing the height adjustment method of an air suspension according to any one of claims 1 to 9 when executing a program stored on a memory.

12. A computer-readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the height adjustment method of an air suspension according to any one of claims 1-9.