Control method, device and electronic equipment of intelligent vehicle

Abstract

The application discloses a control method and device of an intelligent vehicle and electronic equipment. The method is applied to a target vehicle. Wheels of the target vehicle include one front wheel, one rear wheel and two side wheels arranged oppositely. The method comprises the following steps: determining a speed range corresponding to a driving speed of the target vehicle; determining an equivalent wheelbase of the target vehicle based on the speed range and wheel track radii of two non-adjacent wheels of the target vehicle; determining a spatial state constraint set corresponding to the target vehicle based on the equivalent wheelbase and determined kinematic characteristics; determining a front wheel steering angle corresponding to the front wheel based on a model predictive control strategy under the condition that the spatial state constraint set is taken as a constraint condition; and determining a rear wheel steering angle corresponding to the rear wheel and a side wheel steering angle corresponding to each side wheel based on the front wheel steering angle, the equivalent wheelbase and the wheel track radii by using an Ackerman steering control mode. The method controls each wheel, and the control accuracy of the target vehicle is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of intelligent vehicle control, and in particular to a control method and device of an intelligent vehicle and an electronic device. BACKGROUND

[0002] With the development of automobile electrification and intelligence, it is more and more possible to apply automatic driving vehicles to various scenarios such as commuting, sightseeing, and factory patrol. These scenarios have high requirements for the flexibility of vehicles. At present, the structure of most intelligent vehicles is a non-circular chassis, that is, two front wheels are constructed on the front side of the chassis, and two rear wheels are constructed on the rear side. This structure is not flexible in some scenarios. Moreover, in the intelligent control of the vehicle, it is not possible to flexibly control each wheel according to the actual use state of the vehicle, and the control accuracy is low. SUMMARY

[0003] The purpose of the embodiments of the present application is to provide a control method and device of an intelligent vehicle and an electronic device. The method can determine the corresponding control operation for each wheel according to the actual driving state of a target vehicle with a circular or circular-like chassis, thereby improving the control accuracy of the target vehicle.

[0004] To achieve the above purpose, the present application provides a control method of an intelligent vehicle applied to a target vehicle, wherein the wheels of the target vehicle include one front wheel, one rear wheel, and two side wheels arranged opposite to each other, and the method comprises:

[0005] determining a speed range corresponding to the driving speed of the target vehicle;

[0006] determining an equivalent wheelbase of the target vehicle based on the speed range and the track radii of two non-adjacent wheels of the target vehicle, wherein the equivalent wheelbase represents the physical relationship between the front wheel and the steering center line of the target vehicle during turning;

[0007] determining a corresponding set of spatial state constraints of the target vehicle based on the equivalent wheelbase and the determined kinematic characteristics, wherein the set of spatial state constraints represents the logical relationship between the equivalent wheelbase and the kinematic characteristics, and / or the logical relationship between different kinematic characteristics, and the kinematic characteristics at least include one of the following: the geometric center position of the target vehicle, the steering center position, the change information of the vehicle heading angle, and the speed change information;

[0008] determining a corresponding front wheel steering angle of the front wheel based on a model predictive control strategy with the set of spatial state constraints as a constraint condition;

[0009] Based on the front wheel steering angle, the equivalent wheelbase and the track radius, a rear wheel steering angle corresponding to the rear wheel and a side wheel steering angle corresponding to each side wheel are determined by using Ackerman steering control mode, so as to control the target vehicle.

[0010] As an option, the speed range includes three ranges with sequentially increasing values, and in each of the speed ranges, the track radius and the equivalent wheelbase have a corresponding relationship. Based on the speed range and the track radius of two non-adjacent wheels of the target vehicle, the equivalent wheelbase of the target vehicle is determined, including:

[0011] The corresponding relationship of the speed range is determined.

[0012] Based on the track radius and the determined relationship, the equivalent wheelbase is determined.

[0013] As an option, the speed range includes a first speed range, a second speed range and a third speed range; the first speed range, the second speed range and the third speed range are sequentially adjacent and contain sequentially increasing values.

[0014] As an option, a coordinate system is established for the driving state of the target vehicle, and based on the equivalent wheelbase and the determined kinematic characteristics, the spatial state constraint set corresponding to the target vehicle is determined, including:

[0015] The angle information between the vehicle heading of the target vehicle and the coordinate axis of the coordinate system, and the turning radius of the target vehicle are determined.

[0016] In the coordinate system, based on the angle information and the turning radius, the change information of the steering center position is determined.

[0017] Based on the change information of the steering center position, the change information of the geometric center position is determined.

[0018] Based on the change information of the geometric center position, a first spatial state constraint subset in the corresponding spatial state constraint set is determined.

[0019] As an option, a coordinate system is established for the driving state of the target vehicle, and based on the equivalent wheelbase and the determined kinematic characteristics, the spatial state constraint set corresponding to the target vehicle is determined, including:

[0020] The angle information between the vehicle heading of the target vehicle and the coordinate axis of the coordinate system, and the turning radius of the target vehicle are determined.

[0021] In the coordinate system, based on the included angle information and the turning radius, determine the change information of the turning center position;

[0022] Based on the change information of the turning center position, determine the change information of the vehicle heading angle;

[0023] Based on the change information of the vehicle heading angle, determine the second spatial state constraint subset in the corresponding spatial state constraint set.

[0024] As an option, based on the equivalent wheelbase and the determined kinematic characteristics, determining the spatial state constraint set corresponding to the target vehicle, includes:

[0025] In the driving process of the target vehicle, determine the speed change information;

[0026] Based on the speed change information, determine the third spatial state constraint subset in the corresponding spatial state constraint set.

[0027] As an option, in the case of taking the spatial state constraint set as a constraint condition, based on a model predictive control strategy, determine the front wheel steering angle corresponding to the front wheel, includes:

[0028] The distance deviation of the geometric center position from the to-be-tracked trajectory, and the angle deviation of the vehicle heading angle from the to-be-tracked trajectory heading angle, are both taken as cost functions;

[0029] Iteratively calculate the spatial state constraint set to minimize the parameter deviation in the spatial state constraint set and the corresponding value in the to-be-tracked trajectory;

[0030] Based on the correlation between the equivalent wheelbase and the turning radius of the target vehicle, determine the front wheel steering angle.

[0031] As an option, based on the front wheel steering angle, the equivalent wheelbase and the track radius, the rear wheel steering angle corresponding to the rear wheel and the side wheel steering angle corresponding to each side wheel are determined using the Ackerman steering control method, includes:

[0032] Based on the track radius, the track radius and the equivalent wheelbase, determine the rear wheel steering angle, the first side wheel steering angle and the second side wheel steering angle.

[0033] As an option, the method further includes:

[0034] In the case of vehicle control of the target vehicle based on the front wheel steering angle, the rear wheel steering angle and the side wheel steering angle, detect the corresponding control results, which include:

[0035] detect an average deviation distance between a driving track of the target vehicle and a test track;

[0036] determine whether the control result meets a control requirement according to a detection result corresponding to the detection operation.

[0037] The embodiment of the present application further provides a control device of an intelligent vehicle, which is applied to a target vehicle, wherein wheels of the target vehicle include one front wheel, one rear wheel and two side wheels arranged oppositely, and the device includes:

[0038] a determining module configured to determine a speed range corresponding to a driving speed of the target vehicle, and determine an equivalent wheelbase of the target vehicle based on the speed range and a track radius of two non-adjacent wheels of the target vehicle, wherein the equivalent wheelbase represents a physical relationship between the front wheel and a turning center line of the target vehicle in a turning process;

[0039] a space state module configured to determine a space state constraint set corresponding to the target vehicle based on the equivalent wheelbase and determined kinematic characteristics, wherein the space state constraint set represents a logical relationship between the equivalent wheelbase and the kinematic characteristics, and / or a logical relationship between different kinematic characteristics, and the kinematic characteristics at least include one of a geometric center position of the target vehicle, a turning center position, change information of a vehicle heading angle and change information of a speed;

[0040] a processing module configured to determine a front wheel steering angle corresponding to the front wheel based on a model predictive control strategy under the condition that the space state constraint set is taken as a constraint condition, and determine a rear wheel steering angle corresponding to the rear wheel and a side wheel steering angle corresponding to each side wheel by using Ackerman steering control mode based on the front wheel steering angle, the equivalent wheelbase and the track radius, so as to control the target vehicle.

[0041] The embodiment of the present application further provides an electronic device including a processor and a memory, wherein the memory stores an executable program, and the processor executes the executable program to perform steps of the method described above.

[0042] The control method of the embodiment of the present application can determine a corresponding equivalent wheelbase according to a driving speed of a target vehicle, so as to construct a space state equation according to the equivalent wheelbase and kinematic characteristics, and then perform iterative calculation based on the space state equation to realize that a deviation between the target vehicle and a to-be-tracked track is minimum, and then accurately determine wheel steering angles, realize that corresponding control operations are performed on each wheel according to an actual driving state of the target vehicle, and improve control accuracy and intelligence of the target vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 Flow chart of the control method of the intelligent vehicle of the embodiment of the present application;

[0044] Figure 2 Flow chart of the control method of the embodiment of the present application Figure 1 Flow chart of one embodiment of step S200 in the embodiment of the present application;

[0045] Figure 3 Flow chart of the control method of the embodiment of the present application Figure 1 Flow chart of the first embodiment of step S300 in the embodiment of the present application;

[0046] Figure 4 Flow chart of the control method of the embodiment of the present application Figure 1 Flow chart of the second embodiment of step S300 in the embodiment of the present application;

[0047] Figure 5 Flow chart of the control method of the embodiment of the present application Figure 1 Flow chart of the third embodiment of step S300 in the embodiment of the present application;

[0048] Figure 6 Flow chart of the control method of the embodiment of the present application Figure 1 Flow chart of one embodiment of step S400 in the embodiment of the present application;

[0049] Figure 7 Flow chart of the control method of the embodiment of the present application

[0050] Figure 8 Schematic diagram of the distribution of the wheels of the intelligent vehicle on the chassis in the embodiment of the present application;

[0051] Figure 9 Flow chart of one specific embodiment of the control method in the embodiment of the present application;

[0052] Figure 10 Schematic diagram of the steering dynamic process analysis of the full-wheel steering of the circular chassis in the embodiment of the present application;

[0053] Figure 11 Schematic diagram of the calculation of the steering angle of each wheel of the circular chassis in the embodiment of the present application;

[0054] Figure 12 Schematic diagram of the result of tracking the test track in the embodiment of the present application;

[0055] Figure 13 Structural block diagram of the control device of the intelligent vehicle in the embodiment of the present application.

[0056] Explanation of reference numerals

[0057] 10 - chassis; 11 - front wheels; 12 - rear wheels; 13 - side wheels; 14 - steering center position; 15 - geometric center position; 16 - steering center line; 100 - determination module; 200 - spatial state module; 300 - processing module. DETAILED DESCRIPTION

[0058] Various aspects and features of the present application are described herein with reference to the accompanying drawings.

[0059] It is to be understood that various alterations, modifications, and improvements can be made to the embodiments of the application herein disclosed. Accordingly, it is intended to embrace all such alterations, modifications, and improvements as fall within the scope and spirit of the application.

[0060] The accompanying drawings incorporated in and forming a part of the specification illustrate embodiments of the present application and, together with the description given above and the detailed description of the embodiments given below, serve to explain the principles of the application.

[0061] These and other characteristics of the present application will become apparent upon consideration of the following detailed description taken in conjunction with the accompanying drawings.

[0062] It should also be understood that, although the terms "first" and "second" can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element could be termed a second element without departing from the scope of example embodiments of the present application.

[0063] The above and other aspects, features, and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

[0064] Specific embodiments of the present application are described herein with reference to the accompanying drawings. However, it should be noted that the application can be implemented in various ways and should not be limited to the embodiments described herein. It will be apparent to persons skilled in the art that numerous modifications and variations within the scope of the present application are possible in light of this disclosure. Duplicative functionality and structural elements have not been described in detail to avoid obscuring the present application unnecessarily.

[0065] The present specification can use the phrases "in one embodiment," "in another embodiment," "in yet another embodiment," or "in at least one embodiment" to convey that a particular feature, structure, or characteristic described in connection with these phrases can be included in the currently described feature, structure, or characteristic, in one or more embodiments of the application.

[0066] The control method of an intelligent vehicle according to an embodiment of the present application is applied to a target vehicle, and the target vehicle has a circular chassis or a quasi-circular chassis. The wheels of the target vehicle are arranged on the chassis 10, as shown in FIG. 1. Figure 8As shown, the wheels of the target vehicle include: a front wheel 11, a rear wheel 12 and two side wheels 13 arranged oppositely. Specifically, in the driving direction of the target vehicle, among the wheels, the front wheel 11 is located at the frontmost of the target vehicle, the rear wheel 12 is located at the rearmost of the target vehicle, and the two side wheels 13 can be arranged on the left and right sides of the target vehicle respectively. Each wheel can be independently controlled. For example, each wheel on the chassis 10 can be independently controlled to rotate 180° clockwise or counterclockwise, etc.

[0067] The control method of the present application determines the geometric center position 15 of the target vehicle, constructs the spatial state constraint set (spatial state equation) of the vehicle, and determines the steering angle of each wheel under the constraint of the spatial state constraint set using the established model predictive control strategy (MPC) under the constraint of the spatial state constraint set, in the case of the wheelbase variability of the target vehicle, using the intersection of the target vehicle steering center line 16 and the wheel axis, and the equivalent wheelbase of the target vehicle. The equivalent wheelbase can refer to the distance from the front wheel 11 of the target vehicle to the steering center line 16. This method takes into account the steering flexibility at low speed and the steering comfort at high speed by selecting different equivalent wheelbases at different speeds; after the equivalent wheelbase is determined, this method calculates the steering angle of each wheel based on the Ackerman steering principle according to the determined front wheel steering angle, through the geometric relationship between each wheel of the target vehicle and the distance from the steering center line 16, so as to accurately and flexibly control the target vehicle.

[0068] The control method will be described in detail below in conjunction with the drawings, Figure 1 The flowchart of the control method of the intelligent vehicle of the embodiment of the present application is shown as Figure 1 and combined with Figure 9 The method comprises the following steps:

[0069] S100, determine the speed range corresponding to the driving speed of the target vehicle.

[0070] Exemplarily, the speed range can be an interval range of speed, and a plurality of speed ranges are provided in the embodiment. Each speed range is different, and the numerical value of the speed contained therein is different. The speed range can be pre-set.

[0071] The steering control information of the target vehicle includes driving speed, kinematic characteristics and to-be-tracked trajectory and the like. Among them, the steering control information can be obtained during the driving of the target vehicle, including the driving speed, comparing the driving speed with the speed range, the speed range corresponding to the driving speed can be determined. Of course, the driving speed can also be in constant dynamic change, when the driving speed changes, the speed range corresponding to the driving speed can be determined again, and finally the target vehicle can be controlled in real time.

[0072] S200, determining an equivalent wheelbase of the target vehicle based on the speed range and a track radius of two non-adjacent wheels of the target vehicle, wherein the equivalent wheelbase represents a physical relationship between the front wheel 11 and a steering center line 16 of the target vehicle during a turning process of the target vehicle.

[0073] For example, the target vehicle can travel based on a current road (including a straight line and an arc line) or a to-be-tracked trajectory (including a straight line and an arc line). For example, the to-be-tracked trajectory is pre-set on the current road, and the target vehicle can be controlled to travel along the to-be-tracked trajectory. During the turning process of the target vehicle, the center of the arc line corresponding to the body of the target vehicle corresponds to the steering center line 16.

[0074] The equivalent wheelbase represents the physical relationship between the front wheel 11 and the steering center line 16 of the target vehicle during the turning process of the target vehicle. In an embodiment, the equivalent wheelbase refers to the vertical distance between the axis of the front wheel 11 of the target vehicle and the steering center line 16.

[0075] The track radius of the target vehicle is half of the distance between two non-adjacent wheels of the target vehicle. When the chassis 10 of the target vehicle is circular, the track radius can be half of the distance between the front wheel 11 and the rear wheel 12, or half of the distance between the left wheel and the right wheel.

[0076] In this embodiment, the equivalent wheelbase of the target vehicle is determined based on the speed range and the track radius. In different speed ranges, the logical relationship between the equivalent wheelbase and the track radius is different. For example, when the form speed of the target vehicle is in a first speed range, a first equivalent wheelbase is determined based on a first logical relationship between the equivalent wheelbase and the track radius on the premise that the track radius is fixed. When the form speed of the target vehicle is in a second speed range, a second equivalent wheelbase is determined based on a second logical relationship between the equivalent wheelbase and the track radius on the premise that the track radius is fixed. When the form speed of the target vehicle is in a third speed range, a third equivalent wheelbase is determined based on a third logical relationship between the equivalent wheelbase and the track radius on the premise that the track radius is fixed, and so on.

[0077] S300, determining a spatial state constraint set corresponding to the target vehicle based on the equivalent wheelbase and the determined kinematic characteristics, wherein the spatial state constraint set represents a logical relationship between the equivalent wheelbase and the kinematic characteristics, and / or a logical relationship between different kinematic characteristics, the kinematic characteristics at least including one of the following: the geometric center position 15 of the target vehicle, the steering center position 14, the change information of the vehicle heading angle, and the speed change information.

[0078] For example, the kinematic features (kinematic characteristics) are related feature data of the target vehicle in the process of motion. The kinematic features include the geometric center position 15 of the target vehicle, the turning center position 14 of the target vehicle, the change information of the vehicle heading angle, and the change information of the speed. The geometric center position 15 can be related information of the position point where the geometric center of the target vehicle is located. For example, when the target vehicle establishes a coordinate system during driving, the geometric center position 15 can be related position information of the geometric center point in the coordinate system. The turning center position 14 can be the intersection of the front wheel 11 to the perpendicular line on the turning center line 16. The change information of the vehicle heading angle can be the change information of the driving angle of the target vehicle during turning. The change information of the speed can be related information of the change of the driving speed of the target vehicle during driving.

[0079] In this embodiment, based on the equivalent wheelbase and the above-mentioned various kinematic features, the corresponding spatial state constraint set of the target vehicle is determined. The spatial state constraint set can be represented by a spatial state equation. It represents the logical relationship between the equivalent wheelbase and the kinematic features, and / or the logical relationship between different kinematic features. For example, the logical relationship between the equivalent wheelbase, the turning radius, and the front wheel steering angle. The angle information between the vehicle heading of the target vehicle and the coordinate axis of the coordinate system, the logical relationship between the turning radius of the target vehicle and the turning center position 14. The logical relationship between the change information of the turning center position 14 and the change information of the vehicle heading angle, etc.

[0080] The operation of specifically determining the spatial state constraint set can include using a plurality of spatial state constraint subsets (which can be represented in the form of specific sub-equations) that are constructed in advance based on the logical relationship between the equivalent wheelbase and the kinematic features, and the logical relationship between different kinematic features, and then determining the spatial state constraint set based on the plurality of spatial state constraint subsets.

[0081] S400, based on the model predictive control strategy, determine the front wheel steering angle corresponding to the front wheel 11 under the condition that the spatial state constraint set is used as a constraint condition.

[0082] For example, the model predictive control strategy (MPC) adopts a method of obtaining the current control action at each sampling instant by solving a finite time domain open-loop optimal control problem. The current state is used as the initial state of the optimal control problem, and the optimal control sequence obtained is only implemented for the first control action. The model predictive control strategy is actually to solve an open-loop optimal control problem.

[0083] In this embodiment, the spatial state constraint set is taken as a constraint condition, and the spatial state constraint set is iteratively calculated to minimize the deviation between the parameters in the spatial state constraint set and the corresponding values in the to-be-tracked trajectory. In this case, the front wheel steering angle can be accurately determined based on the correlation between the equivalent wheelbase and the turning radius of the target vehicle.

[0084] Of course, the determination of the front wheel steering angle can also be based on other control strategies or control models similar to MPC. Similarly, the front wheel steering angle can be calculated when the spatial state constraint set is taken as a constraint condition.

[0085] S500, based on the front wheel steering angle, the equivalent wheelbase and the track radius, the Ackerman steering control mode is used to determine the corresponding rear wheel steering angle of the rear wheel 12 and the corresponding side wheel steering angle of each side wheel 13 to control the target vehicle.

[0086] For example, the target vehicle has a circular or circular-like chassis, and each wheel is arranged on the chassis 10. Specifically, among each wheel, the front wheel 11 is located at the front of the target vehicle in the driving direction, the rear wheel 12 is located at the rear of the target vehicle in the driving direction, and the two side wheels 13 can be arranged on the left and right sides of the target vehicle, respectively.

[0087] The Ackerman steering control mode is based on the Ackerman principle. It decomposes the control into steering control and speed control, where the steering control is to control the wheel to change along the specified path, and the speed control is to control the wheel speed to move along the specified path. The Ackerman steering control mode includes the logical relationship between all wheel steering angles. Based on the logical relationship and using the Ackerman steering control mode to control the target vehicle to turn, the inside wheel turns at a larger angle than the outside wheel, so that the target vehicle can turn around a center and all the wheel perpendiculars of the target vehicle can point to the center, so that the direction of the resultant force of each wheel under external force is more unified, and the body posture when turning is stable.

[0088] In one embodiment, the logical relationship between the wheel steering angles determined in the Ackerman steering control mode specifically includes the relationship between the front wheel steering angle, the rear wheel steering angle, the side wheel steering angle, the equivalent wheelbase and the track radius. Therefore, after the front wheel steering angle, the equivalent wheelbase and the track radius are determined, the Ackerman steering control mode can be used to determine the corresponding rear wheel steering angle of the rear wheel 12 and the corresponding side wheel steering angle of each side wheel 13, such as the left side wheel steering angle and the right side wheel steering angle. After the wheel steering angles of each wheel are determined, the wheels of the target vehicle can be controlled to rotate according to the corresponding steering angles, thereby achieving flexible and accurate intelligent control.

[0089] The control method of the embodiment of the present application can determine the corresponding equivalent wheelbase according to the driving speed of the target vehicle, so as to construct the space state equation according to the equivalent wheelbase and the kinematic characteristics, and then perform iterative calculation based on the space state equation to minimize the deviation between the target vehicle and the to-be-tracked trajectory, and then accurately determine the steering angle of each wheel, so as to accurately determine the corresponding control operation for each wheel according to the actual driving state of the target vehicle, and improve the control accuracy and intelligence of the target vehicle.

[0090] In an embodiment of the present application, wherein the speed range includes three ranges with sequentially increasing values, in each of the speed ranges, the wheelbase radius and the equivalent wheelbase have a respective corresponding relationship, and the equivalent wheelbase of the target vehicle is determined based on the speed range and the wheelbase radius of the two non-adjacent wheels of the target vehicle, as shown in the following steps: Figure 2

[0091] S210, determining the corresponding relationship of the speed range.

[0092] For example, the relationship between the wheelbase radius and the equivalent wheelbase corresponding to each speed range is different. In the process of increasing the driving speed of the target vehicle, the level of the corresponding speed range will also gradually increase. For example, the driving speed is originally in the first speed range, and the driving speed increases continuously. When the driving speed exceeds the boundary between the first speed range and the second speed range, the driving speed is determined to be in the second speed range, wherein the level of the second speed range is higher than that of the first speed range. Therefore, the relationship between the wheelbase radius and the equivalent wheelbase changes. In an embodiment, the equivalent wheelbase will increase with the increase of the level of the speed range.

[0093] In an embodiment, the speed range includes a first speed range, a second speed range and a third speed range; the first speed range, the second speed range and the third speed range are sequentially adjacent and contain sequentially increasing values.

[0094] Specifically, the first speed range and the second speed range are adjacent, and the second speed range and the third speed range are adjacent. The values in the second speed range increase relative to the values in the first speed range, and the values in the third speed range increase relative to the values in the second speed range.

[0095] S220, determining the equivalent wheelbase based on the wheelbase radius and the determined relationship.

[0096] For example, the relationship between the wheelbase radius and the equivalent wheelbase corresponding to each speed range is relatively fixed. Therefore, the equivalent wheelbase can be calculated based on the wheelbase radius and the determined relationship.​

[0097] In one embodiment, the association relationship can be represented by a specific relationship formula, and then the equivalent wheelbase is determined according to the relationship formula. For example, as follows:

[0098] According to the design parameters and actual use of the circular chassis of the target vehicle, the speed range of the target vehicle is divided. Specifically, the driving speed range of the target vehicle is divided into a low speed range, a medium speed range and a high speed range, and the equivalent wheelbase is divided in each range and the corresponding wheelbase radius. Among them, the low speed range is the first speed range, the medium speed range is the second speed range, and the high speed range is the third speed range.

[0099] The use scenario corresponding to the low speed range is starting, driving through complex or extremely curved roads, and parking at a fixed point. This kind of scene has higher requirements for the steering flexibility of the target vehicle, and since the speed is slow, the comfort of the passengers does not need to be considered. Therefore, for the low speed range, the equivalent wheelbase of the vehicle is set as shown in formula (1):

[0100] L = r (v < 3 km / h) (1)

[0101] Wherein, L is the equivalent wheelbase, v < 3 km / h is the low speed range, i.e. the first speed range, r is the wheelbase radius, v is the driving speed, and 3 km / h is kilometers per hour.

[0102] The use scenario corresponding to the medium speed range is normal sightseeing, patrol and other scenarios. The road driven by the target vehicle under this scenario is often straight, and the curvature radius of the road is often large, so the scene has lower requirements for the flexibility of the vehicle and higher requirements for the comfort of the passengers. At the same time, since the driving speed of the scene is not very fast, the vehicle does not need too long equivalent wheelbase, so for the medium speed range, the equivalent wheelbase of the target vehicle is set as shown in formula (2):

[0103]

[0104] Wherein, L is the equivalent wheelbase, 3 km / h < v < 15 km / h is the medium speed range, i.e. the second speed range, r is the wheelbase radius, and v is the driving speed.

[0105] The use scenario corresponding to the high speed range is passenger transport, transportation and other scenarios. Under this scenario, the target vehicle needs to transport passengers or goods to the destination at a faster speed, and the driving speed of the target vehicle is often high, and the road driven is often an open highway with fewer curves and larger curvature radius than the medium speed range. Due to the faster driving speed, the vehicle needs longer equivalent wheelbase, so for the high speed range, the equivalent wheelbase of the vehicle is set as shown in formula (3):

[0106]

[0107] Wherein, L is the equivalent wheelbase, 15km / h << v << 30km / h is the high speed region, i.e. the third speed range, r is the wheelbase radius, and v is the driving speed.

[0108] In summary, in each speed range of the target vehicle, the equivalent wheelbase of the vehicle can be set according to the driving speed.

[0109] In an embodiment of the present application, a coordinate system is established for the driving state of the target vehicle, and the spatial state constraint set corresponding to the target vehicle is determined based on the equivalent wheelbase and the determined kinematic characteristics, such as Figure 3 as shown, including:

[0110] S301, determining the included angle information between the vehicle heading of the target vehicle and the coordinate axis of the coordinate system, and the turning radius of the target vehicle.

[0111] For example, a coordinate system is established for the driving state of the target vehicle, which can represent the position information of the target vehicle during driving. The coordinate axis of the coordinate system includes the horizontal axis (x-axis) and the vertical axis (y-axis). In an embodiment, the coordinate system takes the north direction as the positive direction of the x-axis and the east direction as the positive direction of the y-axis, and the vehicle heading angle in the coordinate system is 0° with the north direction.

[0112] The vehicle heading is the driving direction of the target vehicle, and the vehicle heading has an included angle with the coordinate axis (such as the horizontal axis) of the coordinate system. In addition, the target vehicle has a corresponding turning radius R during arc driving. The above-mentioned included angle information and turning radius can be detected by using corresponding devices during the driving process of the target vehicle.

[0113] S302, in the coordinate system, based on the included angle information and the turning radius, determining the change information of the turning center position 14.

[0114] For example, with respect to the stationary coordinate system, the turning center position 14 refers to the instantaneous center of all parts and particles of the target vehicle rotating around the same point with different turning radii when the target vehicle turns. Therefore, based on the included angle information and the turning radius, the turning center position 14 and the change information of the turning center position 14 during the driving process of the target vehicle can be determined according to the corresponding geometric relationship.

[0115] S303, based on the change information of the turning center position 14, determining the change information of the geometric center position 15.

[0116] For example, the geometric center position 15 can be the relevant information of the position point where the geometric center of the target vehicle is located, for example, can be the relevant position information of the geometric center point of the target vehicle in the coordinate system. During the driving of the target vehicle, the change information of the geometric center position 15 can be determined based on the change information of the steering center position 14, the equivalent wheelbase and the track radius, by using the geometric relationship thereof.

[0117] In S304, a first spatial state constraint subset in the corresponding spatial state constraint set is determined based on the change information of the geometric center position 15.

[0118] For example, the change information of the geometric center position 15 corresponds to the first spatial state constraint subset. The first spatial state constraint subset contains the mathematical relationship of the position change of the target vehicle in the coordinate system after the position change of the target vehicle.

[0119] The following will be described in detail Figure 10 For example, the kinematic characteristics of the target vehicle are analyzed in a very short time period dt. For any equivalent wheelbase L, when the target vehicle drives forward with a front wheel steering angle and a speed v for a distance ds, the change information of the steering center position 14 (black solid dot, represented as: x1, y1) of the target vehicle, the geometric center position 15 (black hollow dot, represented as: x0, y0) of the target vehicle and the vehicle heading angle are as shown in Figure 10

[0120] It can be analyzed that the vehicle drives a distance ds in dt, which is shown in the following formula (4):

[0121] ds = v*dt = Δθ*R (4)

[0122] Where Δθ is the change information of the vehicle heading angle, and the turning radius is shown in the following formula (5):

[0123]

[0124] Therefore, the change information of the steering center position 14 can be calculated as shown in the following formula (6):

[0125]

[0126] Where x 10 , y 10 is the coordinate system position of the steering center of the target vehicle before the time period dt, x 11 , y 11 ​is the coordinate system position of the geometric center position 15 of the target vehicle after the time period dt. θ0is the included angle between the vehicle heading before the time period dt and the coordinate axis.

[0127] Further, the change information of the geometric center position 15 of the target vehicle can be calculated as shown in the following formula (7):

[0128]

[0129] wherein x 00 , y 00 is the coordinate system position of the geometric center position 15 of the target vehicle before the time period dt, x 01 , y 01 is the coordinate system position of the geometric center position 15 of the target vehicle after the time period dt. θ0is the included angle between the vehicle heading before the time period dt and the coordinate axis, and θ1is the included angle between the vehicle heading after the time period dt and the coordinate axis.

[0130] In an embodiment of the present application, a coordinate system is established for the driving state of the target vehicle, and based on the equivalent wheelbase and the determined kinematic characteristics, a set of spatial state constraints corresponding to the target vehicle is determined, as shown in the following formula (9): Figure 4 The set of spatial state constraints includes the following steps:

[0131] S305, determining the included angle information between the vehicle heading of the target vehicle and the coordinate axis of the coordinate system, and the turning radius of the target vehicle;

[0132] S306, in the coordinate system, based on the included angle information and the turning radius, determining the change information of the turning center position 14;

[0133] S307, based on the change information of the turning center position 14, determining the change information of the vehicle heading angle;

[0134] S308, based on the change information of the vehicle heading angle, determining a second spatial state constraint subset in the set of spatial state constraints.

[0135] For example, similar to the above embodiment, after the change information of the turning center position 14 is determined, the change information of the vehicle heading angle can be determined based on the change information of the turning center position 14, the equivalent wheelbase and the front wheel steering angle, by using the geometric relationship thereof.

[0136] In combination with the above embodiment, the change of the vehicle heading angle can also be calculated as shown in the following formula (8):

[0137]

[0138] Wherein, θ0 is the angle between the vehicle heading and the coordinate axis before the dt time period, θ1 is the angle between the vehicle heading and the coordinate axis after the dt time period. L is the equivalent wheelbase, is the front wheel steering angle, and v is the driving speed.

[0139] The change information of the vehicle heading angle corresponds to a second spatial state constraint subset. The second spatial state constraint subset contains a mathematical relationship of the change of the vehicle heading angle of the target vehicle after the position change.

[0140] In an embodiment of the present application, the spatial state constraint set corresponding to the target vehicle is determined based on the equivalent wheelbase and the determined kinematic characteristics, as shown in the following formula (1): Figure 5 As shown in the following formula (1), the method comprises the following steps:

[0141] S309, determining the speed change information during the driving of the target vehicle;

[0142] S310, determining a third spatial state constraint subset in the spatial state constraint set based on the speed change information.

[0143] For example, the driving speed of the target vehicle may change during the driving of the target vehicle in the dt time period, such as gradually increasing during continuous driving. The speed change information represents the change of the target vehicle before and after the dt time period.

[0144] The speed change information corresponds to a third spatial state constraint subset. The third spatial state constraint subset contains a mathematical relationship of the driving speed of the target vehicle before and after a time period, as shown in the following formula (9):

[0145] v1 = v0 + a*dt

[0146] Wherein, v0 is the driving speed of the target vehicle before the dt time period, v1 is the driving speed of the target vehicle after the dt time period, and a is the acceleration of the target vehicle.

[0147] Based on the above formula (1) to formula (9), the spatial state equation (spatial state constraint set) of the target vehicle can be determined, as shown in the following formula (10):

[0148]

[0149] In an embodiment of the present application, the front wheel steering angle corresponding to the front wheel 11 is determined based on the model predictive control strategy under the condition that the spatial state constraint set is used as a constraint condition, as shown in the following formula (2): Figure 6 As shown in the following formula (2), the method comprises the following steps:

[0150] S410, taking the distance deviation of the geometric center position 15 from the to-be-tracked trajectory and the angle deviation of the vehicle heading angle from the to-be-tracked trajectory heading angle as cost functions;

[0151] S420, iteratively calculating the spatial state constraint set to minimize the parameter deviation in the spatial state constraint set from the corresponding value in the to-be-tracked trajectory;

[0152] S430, determining the front wheel steering angle based on the correlation between the equivalent wheelbase and the turning radius of the target vehicle.

[0153] For example, the model predictive control strategy adopts a current control action at each sampling instant by solving a finite-time open-loop optimal control problem, taking the current state as the initial state of the optimal control problem, and implementing only the first control action in the optimal control sequence. Using this principle, the distance deviation of the geometric center position 15 from the to-be-tracked trajectory is taken as a cost function, and the angle deviation of the vehicle heading angle from the to-be-tracked trajectory heading angle is also taken as a cost function, where the cost function is also a loss function, which is the optimization condition of the model predictive control strategy, and can be associated with the learning criterion and the optimization problem, i.e., solving and evaluating the model (model predictive control strategy) by minimizing the loss function.

[0154] The spatial state constraint set is iteratively calculated to minimize the parameter deviation in the spatial state constraint set from the corresponding value in the to-be-tracked trajectory, i.e., to minimize the deviation between the actual driving path of the target vehicle during driving and the to-be-tracked trajectory, and then the front wheel steering angle is determined based on the correlation between the equivalent wheelbase and the turning radius of the target vehicle, so that the determined front wheel steering angle is most accurate.

[0155] In an embodiment of the present application, the determination of the corresponding rear wheel steering angle of the rear wheel 12 and the corresponding side wheel steering angle of each side wheel 13 based on the front wheel steering angle, the equivalent wheelbase, and the wheelbase radius using the Ackermann steering control method includes:

[0156] Based on the wheelbase radius, the wheelbase radius, and the equivalent wheelbase, the rear wheel steering angle, the first side wheel steering angle, and the second side wheel steering angle are determined.

[0157] For example, according to the calculated front wheel steering angle, the steering angles of each wheel of the vehicle can be calculated according to the Ackermann principle and the geometric characteristics of the vehicle, as shown in the following formula (11): Figure 11

[0158] ​

[0159] wherein, is a front wheel steering angle, is a left side wheel steering angle, is a right side wheel steering angle, is a rear wheel steering angle, L is an equivalent wheelbase, and r is a track radius. Thus, the steering angles of each wheel of the target vehicle are determined, and then the corresponding wheels can be controlled according to the steering angles of each wheel, thereby achieving flexible and accurate control of the target vehicle.

[0160] In an embodiment of the present application, the method further comprises the following steps:

[0161] In the case of vehicle control of the target vehicle based on the front wheel steering angle, the rear wheel steering angle, and the side wheel steering angle, the corresponding control result is detected, such as Figure 7 as shown and in combination with Figure 9 wherein, including:

[0162] S510, detecting the average deviation distance between the driving trajectory of the target vehicle and the test trajectory;

[0163] S520, determining whether the control result meets the control requirement according to the detection result corresponding to the detection operation.

[0164] For example, in order to verify whether the front wheel steering angle, the rear wheel steering angle, and the side wheel steering angle are accurate, i.e., whether accurate control of the target vehicle can be achieved, the control result of the target vehicle can be verified based on the actual running state of the target vehicle.

[0165] Specifically, a test trajectory is drawn in advance, wherein the test trajectory can be the same as or different from the to-be-tracked trajectory. The target vehicle is controlled to drive along the test trajectory, but there will be a deviation between the actual driving trajectory of the target vehicle and the test trajectory during actual driving. In the detection of the control result, the average deviation distance between the driving trajectory of the target vehicle and the test trajectory can be detected.

[0166] For example, the average deviation distance is shown in the following formula (12):

[0167] D = mean(d0)

[0168] wherein, D is the average deviation distance, and d0 is the deviation distance of the actual driving trajectory of the target vehicle.

[0169] For example, the wheels are arranged on a circular chassis 10 with a diameter of 1.95 meters, i.e., r = 0.975 meters. As Figure 12As shown, a to-be-tracked trajectory is tracked in advance. Through real vehicle test, the tracking result of the control method on the trajectory can be obtained. From the tracking situation, the target vehicle can track the medium-high speed curve with large radius and the low speed curve with small radius well, meeting the design requirement of high-low speed compatibility. From the tracking deviation, the tracking effect of the target vehicle is good, and there is only tracking deviation in part of the curve with small radius or complex angle. From the tracking trajectory deviation distance, the average tracking deviation distance of the trajectory under the control method is 0.18 meters, and the width of the vehicle is 1.95 meters. Therefore, the average deviation distance is small, and the purpose of accurate control is achieved.

[0170] In an embodiment of the present application, the detection of the corresponding control result can also include detection of the control result from other factors. For example, during driving, detection can be performed from at least one of the following aspects: the riding comfort of the target vehicle, and the adjustment continuity of the equivalent wheelbase. The adjustment continuity of the equivalent wheelbase means that the target vehicle can adjust to a shorter equivalent wheelbase to pass through a curve with a smaller radius, and can pass through a curve with a larger radius in a more comfortable manner with a longer equivalent wheelbase, achieving the purpose of flexibility and comfort of the vehicle.

[0171] Based on the same inventive concept, the embodiments of the present application also provide a control device of an intelligent vehicle, which is applied to a target vehicle, such as Figure 8 and Figure 13 As shown, the wheels of the target vehicle include: one front wheel 11, one rear wheel 12, and two side wheels 13 arranged opposite to each other, and the device includes:

[0172] A determination module 100 configured to determine a speed range corresponding to the driving speed of the target vehicle, and determine an equivalent wheelbase of the target vehicle based on the speed range and the track radius of the two non-adjacent wheels of the target vehicle, wherein the equivalent wheelbase represents the physical relationship between the front wheel 11 and the center line 16 of the target vehicle during turning.

[0173] For example, the speed range can be an interval range of speed, and in the embodiment, a plurality of speed ranges are provided. Each speed range is different, and the values of the speeds contained therein are different. The speed range can be pre-set.

[0174] The steering control information of the target vehicle includes information such as a driving speed, a kinematic characteristic, and a to-be-tracked trajectory. The steering control information can be obtained by the determination module 100 when the target vehicle is driving, including the driving speed. The driving speed corresponding speed range can be determined by comparing the driving speed with the speed range. Of course, the driving speed can also be dynamically changing. When the driving speed changes, the determination module 100 can re-determine the driving speed corresponding speed range, and thus the target vehicle can be controlled in real time.

[0175] The target vehicle can drive based on a current road (including a straight line and an arc line) or a to-be-tracked trajectory (including a straight line and an arc line). For example, the to-be-tracked trajectory is pre-set on the current road, and the target vehicle can be controlled to drive along the to-be-tracked trajectory. During the turning of the target vehicle, the perpendicular line between the center of the arc line passed by the vehicle body and the direction of the vehicle body is the steering center line 16.

[0176] The equivalent wheelbase represents the physical relationship between the front wheel 11 and the steering center line 16 of the target vehicle during turning. In an embodiment, the equivalent wheelbase refers to the vertical distance between the axis of the front wheel 11 of the target vehicle and the steering center line 16.

[0177] The wheelbase radius of the target vehicle is half of the distance between two non-adjacent wheels of the target vehicle. When the chassis 10 of the target vehicle is circular, the wheelbase radius can be half of the distance between the front wheel 11 and the rear wheel 12, or half of the distance between the left wheel and the right wheel.

[0178] In the embodiment, the determination module 100 determines the equivalent wheelbase of the target vehicle based on the speed range and the wheelbase radius. The logical relationship between the equivalent wheelbase and the wheelbase radius is different at different speed ranges. For example, when the form speed of the target vehicle is in the first speed range, the first equivalent wheelbase is determined based on the first logical relationship between the equivalent wheelbase and the wheelbase radius under the condition that the wheelbase radius is fixed. When the form speed of the target vehicle is in the second speed range, the second equivalent wheelbase is determined based on the second logical relationship between the equivalent wheelbase and the wheelbase radius under the condition that the wheelbase radius is fixed. When the form speed of the target vehicle is in the third speed range, the third equivalent wheelbase is determined based on the third logical relationship between the equivalent wheelbase and the wheelbase radius under the condition that the wheelbase radius is fixed, and so on.

[0179] a space state module 200 configured to determine kinematic features of the target vehicle, and determine a space state constraint set corresponding to the target vehicle based on the equivalent wheelbase and the determined kinematic features, wherein the space state constraint set represents logical relationships between the equivalent wheelbase and the kinematic features, and / or logical relationships between different kinematic features, the kinematic features including at least one of: a geometric center position 15 of the target vehicle, a steering center position 14 of the target vehicle, a change in a vehicle heading angle, and a change in a vehicle speed.

[0180] For example, the kinematic features (kinematic characteristics) are relevant feature data of the target vehicle during movement. The kinematic features include the geometric center position 15 of the target vehicle, the steering center position 14 of the target vehicle, the change in the vehicle heading angle, and the change in the vehicle speed. The geometric center position 15 can be relevant information of a position point of the geometric center of the target vehicle, for example, when a coordinate system is established during movement of the target vehicle, the geometric center position 15 can be relevant position information of the geometric center point in the coordinate system. The steering center position 14 can be the intersection of the front wheel 11 to the perpendicular line on the steering center line 16. The change in the vehicle heading angle can be the change in the travel angle of the target vehicle during turning. The change in the vehicle speed can be relevant information of the change in the travel speed of the target vehicle during movement.

[0181] In this embodiment, the space state module 200 determines the space state constraint set corresponding to the target vehicle based on the equivalent wheelbase and the above-mentioned kinematic features. The space state constraint set can be represented by a space state equation. It represents the logical relationships between the equivalent wheelbase and the kinematic features, and / or the logical relationships between different kinematic features. For example, the logical relationships between the equivalent wheelbase, the turning radius, and the front wheel steering angle. The angle information between the vehicle heading of the target vehicle and the coordinate axis of the coordinate system, the logical relationships between the turning radius of the target vehicle and the steering center position 14. The logical relationships between the change information of the steering center position 14 and the change information of the vehicle heading angle, etc.

[0182] The operation of the space state module 200 to specifically determine the space state constraint set can include using a plurality of space state constraint subsets (which can be represented in the form of specific sub-equations) that are pre-constructed based on the logical relationships between the equivalent wheelbase and the kinematic features, and the logical relationships between different kinematic features, and determining the space state constraint set based on the plurality of space state constraint subsets.

[0183] The processing module 300 is configured to determine, based on a model predictive control strategy, a front wheel steering angle corresponding to the front wheel 11 under the condition that the set of spatial state constraints is taken as a constraint condition; and determine, based on the front wheel steering angle, the equivalent wheelbase and the track radius, a rear wheel steering angle corresponding to the rear wheel 12 and a side wheel steering angle corresponding to each of the side wheels 13 by using the Ackermann steering control mode, so as to control the target vehicle.

[0184] For example, the model predictive control strategy (MPC) adopts a method of obtaining a current control action at each sampling moment by solving a finite-time open-loop optimal control problem. The current state is taken as an initial state of the optimal control problem, and the optimal control sequence is only implemented for the first control action. The model predictive control strategy is actually to solve an open-loop optimal control problem.

[0185] In this embodiment, the processing module 300 takes the set of spatial state constraints as a constraint condition by using the model predictive control strategy, iteratively calculates the set of spatial state constraints, and minimizes the deviation between the parameters in the set of spatial state constraints and the corresponding values in the trajectory to be tracked in the process of multiple optimal calculations. In this case, the front wheel steering angle can be accurately determined based on the correlation between the equivalent wheelbase and the turning radius of the target vehicle.

[0186] Of course, the processing module 300 can also determine the front wheel steering angle based on other control strategies or control models similar to MPC. Similarly, the front wheel steering angle can be calculated under the condition that the set of spatial state constraints is taken as a constraint condition.

[0187] In one embodiment, the target vehicle has a circular or circular-like chassis, and each wheel is arranged on the chassis 10. Specifically, among the wheels, the front wheel 11 is located at the frontmost position in the driving direction of the target vehicle, the rear wheel 12 is located at the rearmost position in the driving direction of the target vehicle, and the two side wheels 13 can be arranged on the left and right sides of the target vehicle, respectively.

[0188] The Ackermann steering control mode is constructed based on the Ackermann principle. It decomposes the control into steering control and speed control, where the steering control is to control the wheels to change along a specified path, and the speed control is to control the wheel speed to move along a specified path. The Ackermann steering control mode includes the logical relationship between all wheel steering angles. When the processing module 300 controls the target vehicle to turn based on the logical relationship and by using the Ackermann steering control mode, the inside wheel has a larger turning angle than the outside wheel, so that the target vehicle can turn around a center, and all the wheel perpendicular lines of the target vehicle can point to the center, so that the direction of the resultant force of each wheel under external force is more uniform, and the posture of the vehicle body when turning is stable.

[0189] In one embodiment, the logical relationship between the steering angles of the wheels determined by the Ackerman steering control mode specifically includes the relationship between the front wheel steering angle, the rear wheel steering angle, the side wheel steering angle, the equivalent wheelbase and the track radius. Thus, after the front wheel steering angle, the equivalent wheelbase and the track radius are determined, the processing module 300 can determine the rear wheel steering angle corresponding to the rear wheel 12 and the side wheel steering angle corresponding to each side wheel 13, such as the left side wheel steering angle and the right side wheel steering angle, by using the Ackerman steering control mode. After the processing module 300 determines the steering angles of the wheels, the wheels of the target vehicle can be controlled to rotate according to the corresponding steering angles, thereby achieving flexible and accurate intelligent control.

[0190] In one embodiment of the present application, the speed range includes three ranges with sequentially increasing values, and in each of the speed ranges, the track radius and the equivalent wheelbase have a corresponding relationship. The determining module 100 is further configured to:

[0191] determine the corresponding relationship between the track radius and the equivalent wheelbase in each of the speed ranges;

[0192] determine the equivalent wheelbase based on the track radius and the determined relationship.

[0193] In one embodiment of the present application, the speed range includes a first speed range, a second speed range and a third speed range; the first speed range, the second speed range and the third speed range are sequentially adjacent and contain sequentially increasing values.

[0194] In one embodiment of the present application, a coordinate system is established for the driving state of the target vehicle, and the spatial state module 200 is further configured to:

[0195] determine the included angle information between the vehicle heading of the target vehicle and the coordinate axis of the coordinate system, and the turning radius of the target vehicle;

[0196] determine the change information of the steering center position 14 in the coordinate system based on the included angle information and the turning radius;

[0197] determine the change information of the geometric center position 15 based on the change information of the steering center position 14;

[0198] determine the first spatial state constraint subset in the corresponding spatial state constraint set based on the change information of the geometric center position 15.

[0199] In one embodiment of the present application, a coordinate system is established for the driving state of the target vehicle, and the spatial state module 200 is further configured to:

[0200] determining an angle information between a vehicle heading of the target vehicle and a coordinate axis of the coordinate system, and a turning radius of the target vehicle;

[0201] in the coordinate system, based on the angle information and the turning radius, determining change information of the turning center position 14;

[0202] based on the change information of the turning center position 14, determining change information of the vehicle heading angle;

[0203] based on the change information of the vehicle heading angle, determining a second spatial state constraint subset in the corresponding spatial state constraint set.

[0204] In an embodiment of the present application, the spatial state module 200 is further configured to:

[0205] in the driving process of the target vehicle, determining the speed change information;

[0206] based on the speed change information, determining a third spatial state constraint subset in the corresponding spatial state constraint set.

[0207] In an embodiment of the present application, the processing module 300 is further configured to:

[0208] the distance deviation of the geometric center position 15 from the to-be-tracked trajectory, and the angle deviation of the vehicle heading angle from the to-be-tracked trajectory heading angle, are both taken as cost functions;

[0209] iteratively calculating the spatial state constraint set so as to minimize the parameter deviation in the spatial state constraint set from the corresponding value in the to-be-tracked trajectory;

[0210] based on the correlation between the equivalent wheelbase and the turning radius of the target vehicle, determining the front wheel steering angle.

[0211] In an embodiment of the present application, the processing module 300 is further configured to:

[0212] based on the wheelbase radius, the wheelbase radius and the equivalent wheelbase, determining the rear wheel steering angle, the first side wheel steering angle and the second side wheel steering angle.

[0213] In an embodiment of the present application, the device further comprises a detection module, which is configured to:

[0214] in the case of vehicle control of the target vehicle based on the front wheel steering angle, the rear wheel steering angle and the side wheel steering angle, detecting the corresponding control results, which include:

[0215] detecting an average deviation distance between a driving track of the target vehicle and a track to be tracked;

[0216] determining whether the control result meets a control requirement according to a detection result corresponding to the detecting operation.

[0217] The embodiments of the present application also provide an electronic device, including a processor and a memory, the memory storing an executable program, and the processor executing the executable program to perform the steps of the method.

[0218] The embodiments of the present application also provide a computer readable storage medium, which carries one or more computer programs, and the one or more computer programs are executed by a processor to implement the steps of the method.

[0219] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, an electronic device, a computer readable storage medium or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware. Furthermore, the present application can take the form of a computer program product implemented on one or more computer usable storage media (including a computer readable storage medium) having a computer usable program code embodied therein. When implemented by software, the functions can be stored in a computer readable medium or transmitted as one or more instructions or code on a computer readable medium.

[0220] The processor can be a general processor, a digital signal processor, an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof. The general processor can be a microprocessor or any conventional processor.

[0221] The memory can include a non-persistent memory in a computer readable medium, a random access memory (RAM) and / or a non-volatile memory such as a read-only memory (ROM) or a flash memory. The memory is an example of the computer readable medium.

[0222] The readable storage medium can be a magnetic disc, an optical disc, a DVD, a USB, a read-only memory (ROM), a random access memory (RAM), or the like, and the specific storage medium form is not limited in the present application.

[0223] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present application within the spirit and protection scope of the present application, and such modifications or equivalent replacements shall also be considered to fall within the protection scope of the present application.

Claims

1. A control method for an intelligent vehicle, characterized in that: Applied to a target vehicle, the wheels of the target vehicle include: a front wheel, a rear wheel, and two side wheels arranged opposite to each other, the method includes: Determine the speed range corresponding to the target vehicle's travel speed; determining an equivalent wheelbase of the target vehicle based on the speed range and the wheelbase radius of two non-adjacent wheels of the target vehicle, wherein the equivalent wheelbase represents a physical relationship between the front wheels and a turning centerline of the target vehicle during a turn; Determining a spatial state constraint set corresponding to the target vehicle based on the equivalent wheelbase and the determined kinematic characteristics, wherein the spatial state constraint set represents a logical relationship between the equivalent wheelbase and the kinematic characteristics, and / or a logical relationship between different kinematic characteristics, wherein the kinematic characteristics include at least one of the following: a geometric center position, a steering center position, change information of a vehicle heading angle, and speed change information of the target vehicle; determining a front wheel steering angle corresponding to the front wheel based on a model predictive control strategy while taking the spatial state constraint set as a constraint condition; Based on the front wheel steering angle, the equivalent wheelbase and the wheelbase radius, using an Ackerman steering control method, determining the rear wheel steering angle corresponding to the rear wheel and the side wheel steering angle corresponding to each of the side wheels to control the target vehicle; The speed range includes three ranges with increasing values ​​in sequence, and in each speed range, there is a corresponding correlation between the wheelbase radius and the equivalent wheelbase. The determining the equivalent wheelbase of the target vehicle based on the speed range and the wheelbase radius of two non-adjacent wheels of the target vehicle includes: Determining the association relationship corresponding to the speed range; Determining the equivalent wheelbase based on the wheelbase radius and the determined association relationship; A coordinate system is established for the driving state of the target vehicle. The spatial state constraint set corresponding to the target vehicle is determined based on the equivalent wheelbase and the determined kinematic characteristics, including: Determining angle information between the vehicle heading of the target vehicle and the coordinate axes of the coordinate system, and a turning radius of the target vehicle; In the coordinate system, determining change information of the turning center position based on the angle information and the turning radius; determining the change information of the geometric center position based on the change information of the steering center position; Determining a first spatial state constraint subset of the corresponding spatial state constraint set based on the change information of the geometric center position; Determining angle information between the vehicle heading of the target vehicle and the coordinate axes of the coordinate system, and a turning radius of the target vehicle; In the coordinate system, determining change information of the turning center position based on the angle information and the turning radius; determining, based on the change information of the steering center position, change information of the vehicle heading angle; Determining a second spatial state constraint subset of the corresponding spatial state constraint set based on the change information of the vehicle heading angle; During the travel of the target vehicle, determining the speed change information; Determining a third spatial state constraint subset in the corresponding spatial state constraint set based on the speed change information; The determining of the front wheel steering angle corresponding to the front wheel based on the model predictive control strategy when the spatial state constraint set is used as a constraint condition includes: The distance deviation between the geometric center position and the track to be tracked, and the angular deviation between the vehicle heading angle and the track to be tracked are both used as cost functions; Iteratively calculating the spatial state constraint set to minimize the deviation between the parameters in the spatial state constraint set and the corresponding numerical values ​​in the trajectory to be tracked; The front wheel steering angle is determined based on a correlation between the equivalent wheelbase and the turning radius of the target vehicle.

2. The method according to claim 1, characterized in that in, The speed range includes a first speed range, a second speed range and a third speed range; the first speed range, the second speed range and the third speed range are adjacent to each other in sequence, and the values ​​included therein increase in sequence.

3. The method according to claim 1, characterized in that The method of determining the rear wheel steering angle corresponding to the rear wheel and the side wheel steering angle corresponding to each side wheel by using an Ackerman steering control method based on the front wheel steering angle, the equivalent wheelbase and the wheelbase radius includes: The rear wheel steering angle, the first side wheel steering angle, and the second side wheel steering angle are determined based on the wheelbase radius, the front wheel steering angle, and the equivalent wheelbase.

4. The method according to claim 1, wherein The method further comprises: When the target vehicle is controlled based on the front wheel steering angle, the rear wheel steering angle, and the side wheel steering angle, corresponding control results are detected, including: Performing a detection operation on an average deviation distance between the driving trajectory of the target vehicle and the test trajectory; Determine whether the control result meets the control requirement based on the detection result corresponding to the detection operation.

5. A control device for an intelligent vehicle, characterized in that: Applied to a target vehicle, the wheels of the target vehicle include: a front wheel, a rear wheel and two side wheels arranged opposite to each other, and the device includes: a determination module configured to determine a speed range corresponding to a driving speed of a target vehicle; and determine an equivalent wheelbase of the target vehicle based on the speed range and a wheelbase radius of two non-adjacent wheels of the target vehicle, wherein the equivalent wheelbase represents a physical relationship between the front wheels of the target vehicle and a turning centerline of the target vehicle during a turn; a spatial state module configured to determine a spatial state constraint set corresponding to the target vehicle based on the equivalent wheelbase and the determined kinematic characteristics, wherein the spatial state constraint set represents a logical relationship between the equivalent wheelbase and the kinematic characteristics, and / or a logical relationship between different kinematic characteristics, wherein the kinematic characteristics include at least one of the following: geometric center position, steering center position, vehicle heading angle change information, and speed change information of the target vehicle; a processing module configured to determine, based on a model predictive control strategy and with the spatial state constraint set as a constraint condition, a front wheel steering angle corresponding to the front wheel; and determine, based on the front wheel steering angle, the equivalent wheelbase, and the wheelbase radius, a rear wheel steering angle corresponding to the rear wheel and a side wheel steering angle corresponding to each of the side wheels using an Ackerman steering control method, so as to control the target vehicle; The speed range includes three ranges with increasing values ​​in sequence. In each speed range, there is a corresponding correlation between the wheelbase radius and the equivalent wheelbase. The determination module is further configured to: Determining the association relationship corresponding to the speed range; Determining the equivalent wheelbase based on the wheelbase radius and the determined association relationship; A coordinate system is established for the driving state of the target vehicle, and the spatial state module is further configured as follows: Determining angle information between the vehicle heading of the target vehicle and the coordinate axes of the coordinate system, and a turning radius of the target vehicle; In the coordinate system, determining change information of the turning center position based on the angle information and the turning radius; determining the change information of the geometric center position based on the change information of the steering center position; Determining a first spatial state constraint subset of the corresponding spatial state constraint set based on the change information of the geometric center position; Determining angle information between the vehicle heading of the target vehicle and the coordinate axes of the coordinate system, and a turning radius of the target vehicle; In the coordinate system, determining change information of the turning center position based on the angle information and the turning radius; determining, based on the change information of the steering center position, change information of the vehicle heading angle; Determining a second spatial state constraint subset of the corresponding spatial state constraint set based on the change information of the vehicle heading angle; During the travel of the target vehicle, determining the speed change information; Determining a third spatial state constraint subset in the corresponding spatial state constraint set based on the speed change information; The processing module is further configured to: The distance deviation between the geometric center position and the track to be tracked, and the angular deviation between the vehicle heading angle and the track to be tracked are both used as cost functions; Iteratively calculating the spatial state constraint set to minimize the deviation between the parameters in the spatial state constraint set and the corresponding numerical values ​​in the trajectory to be tracked; The front wheel steering angle is determined based on a correlation between the equivalent wheelbase and the turning radius of the target vehicle.

6. An electronic device, characterized in that: The method comprises a processor and a memory, wherein an executable program is stored in the memory, and the processor executes the executable program to perform the steps of the method according to any one of claims 1 to 4.

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