Truck path planning method and device under curve coordinate system and electronic equipment

Abstract

The invention relates to a truck path planning method and device under a curve coordinate system and electronic equipment. The truck path planning method under the curve coordinate system is applied to the technical field of vehicle path planning, and comprises the following steps: during truck path planning, adopting an overall state-space equation comprising kinematic models of a tractor and a trailer, and performing curve coordinate system conversion and linearization processing on the overall state-space equation to obtain a truck path planning result; determining the projections of the tractor and the trailer on the reference line; based on the projections of the tractor and the trailer on the reference line, respectively determining the transverse position deviations of the centers of the rear axles of the tractor and the trailer to construct an optimized objective function, and then based on constraint conditions, solving the optimized objective function, determining an optimized variable and determining a planned path of the truck. Therefore, the accuracy of obstacle avoidance during path planning is effectively improved.

Description

Technical Field

[0001] The present disclosure relates to the field of autonomous driving technology, and in particular to a truck path planning method in a curved coordinate system, a truck path planning device in a curved coordinate system, a storage medium, and an electronic device. Background Art

[0002] For unmanned vehicles or manually driven vehicles that may have blind spots during driving, path planning is generally required to avoid collisions with obstacles. Related technologies include path planning methods based on search, sampling, or optimization, but these common methods are not applicable to path planning for trailer vehicles. During path planning and obstacle avoidance, the resulting planned path is inaccurate and prone to collisions with obstacles. Summary of the Invention

[0003] In view of this, embodiments of the present disclosure are intended to provide a truck path planning method in a curvilinear coordinate system, a truck path planning device in a curvilinear coordinate system, a storage medium, and an electronic device.

[0004] The technical solution of the present disclosure is achieved as follows:

[0005] In a first aspect, the present disclosure provides a truck path planning method in a curvilinear coordinate system.

[0006] The truck path planning method in a curvilinear coordinate system provided by the embodiments of the present disclosure includes:

[0007] Establish an overall state space equation for the truck, wherein the overall state space equation includes a kinematic model of the tractor and the trailer; wherein the kinematic model of the tractor and the kinematic model of the trailer are the same model; wherein the overall state space equation includes:

[0008] in, is the time derivative of the vehicle's displacement on the reference line, υ is the vehicle's longitudinal velocity along the vehicle's heading direction, κ is the curvature of the trajectory of the tractor's rear axle center, and κ r is the curvature of the vehicle at the reference line matching point, L2 is the distance from the trailer hinge point to the rear axle, d is the distance from the center of the rear axle of the migration vehicle to the hinge point, and e y is the distance between the center of the tractor's rear axle and the matching point on the reference line, is the heading angle deviation between the center of the tractor's rear axle and the matching point on the reference line, β is the heading angle deviation between the trailer and the tractor, It is e y The derivative with respect to time, yes The derivative with respect to time, is the derivative of β with respect to time;

[0009] Converting the overall state-space equation into a curvilinear coordinate system and performing linearization processing at the equilibrium point to obtain a linearized state-space equation;

[0010] Based on the linearized state space equation, the projections of the tractor and trailer on the reference line are determined using a circular arc approximation method;

[0011] Determining the lateral position deviations of the tractor and trailer at the rear axle centers based on the projections of the tractor and trailer on the reference line;

[0012] Establishing an optimization problem model, the optimization problem model including optimization variables, an optimization objective function, and constraints; wherein the optimization objective function is constructed based on the lateral position deviation at the rear axle centers of the tractor and trailer; the optimization variables include the lateral position deviation, heading angle deviation, and curvature at the rear axle centers of the tractor and trailer; and the constraints include at least one of the following: a kinematic constraint, a starting point constraint, an end point constraint, a tire-in-lane constraint, a collision-free constraint, a curvature constraint, and a curvature change rate constraint;

[0013] Based on the optimization variables and the constraints, the optimization objective function is solved to determine the planned path of the truck.

[0014] In some embodiments, converting the overall state-space equation into a curvilinear coordinate system and performing linearization processing at the equilibrium point to obtain a linearized state-space equation includes:

[0015] Converting the overall state space equation into a curvilinear coordinate system to obtain a curvilinear state space equation;

[0016] The curve state space equation is linearized at the equilibrium point to obtain a linearized state space equation; wherein the curve state space equation is

[0017]

[0018] The linearized state space equation is:

[0019] in,

[0020] Among them, e′ y It is e y The derivative of displacement S is: yes The derivative of displacement S, β′ is the derivative of β with respect to displacement S, is the heading angle deviation between the center of the tractor's rear axle at the balance point and the matching point on the reference line, is the heading angle deviation of the trailer and tractor at the equilibrium point, is the distance between the center of the tractor's rear axle at the equilibrium point and the matching point on the reference line, is the curvature of the trajectory of the rear axle center of the tractor at the equilibrium point, Indicates the balance point.

[0021] In some embodiments, determining the projections of the tractor and trailer on the reference line using a circular arc approximation method based on the linearized state-space equation includes:

[0022] Determine the coordinates of the rear axle center of the tractor in the curvilinear coordinate system;

[0023] Determining the distance between the center of the rear axle of the tractor and the matching point on the reference line based on the coordinates of the center of the rear axle of the tractor in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the tractor;

[0024] Determine the coordinates of the trailer's rear axle center in the curvilinear coordinate system;

[0025] Based on the coordinates of the trailer's rear axle center in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the trailer, the distance between the trailer's rear axle center and the matching point on the reference line is determined.

[0026] In some embodiments, the optimization objective function includes:

[0027] in,

[0028] are the lateral position deviations of the rear axle centers of the tractor and trailer, respectively; J is the overall optimization objective function, where Je represents the minimum difference between the area swept by the tractor and the area swept by the trailer; J κ represents the expectation of smoothness of the planned path; i refers to the order of the optimization variables; K i represents the i-th curvature of the driving trajectory of the rear axle center of the tractor, K i+1 Represents the i+1th curvature of the driving trajectory of the rear axle center of the tractor.

[0029] In some embodiments, solving the optimization objective function based on the optimization variables and the constraints to determine the planned path of the truck includes:

[0030] Based on the constraints, a total optimization objective function in the optimization objective function is minimized, a difference between the expected area swept by the tractor and the area swept by the trailer in the optimization objective function is minimized, and an expected smoothness of the planned path is minimized to obtain optimization variables corresponding to the constraints;

[0031] Based on the optimization variables, a planned path for the truck is determined.

[0032] In a second aspect, the present disclosure provides a truck path planning device in a curvilinear coordinate system, comprising:

[0033] A space equation establishment module is used to establish the overall state space equation of the truck, wherein the overall state space equation includes the kinematic model of the tractor and the trailer; wherein the kinematic model of the tractor and the kinematic model of the trailer are the same model; wherein the overall state space equation includes:

[0034] in, is the time derivative of the vehicle's displacement on the reference line, υ is the vehicle's longitudinal velocity along the vehicle's heading direction, κ is the curvature of the trajectory of the tractor's rear axle center, and κ r is the curvature of the vehicle at the reference line matching point, L2 is the distance from the trailer hinge point to the rear axle, d is the distance from the center of the rear axle of the migration vehicle to the hinge point, and e y is the distance between the center of the tractor's rear axle and the matching point on the reference line, is the heading angle deviation between the center of the tractor's rear axle and the matching point on the reference line, β is the heading angle deviation between the trailer and the tractor, It is e y The derivative with respect to time, yes The derivative with respect to time, is the derivative of β with respect to time;

[0035] A linearization module, configured to convert the overall state-space equation into a curvilinear coordinate system and perform linearization processing at the equilibrium point to obtain a linearized state-space equation;

[0036] a projection determination module for determining the projections of the tractor and trailer on the reference line using a circular arc approximation device based on the linearized state space equation;

[0037] a position deviation determining module for determining lateral position deviations at the rear axle centers of the tractor and trailer, respectively, based on projections of the tractor and trailer on a reference line;

[0038] a model building module for building an optimization problem model, the optimization problem model including optimization variables, an optimization objective function, and constraints; wherein the optimization objective function is constructed based on the lateral position deviation at the rear axle centers of the tractor and trailer; the optimization variables include the lateral position deviation, heading angle deviation, and curvature at the rear axle centers of the tractor and trailer; and the constraints include at least one of the following: a kinematic constraint, a starting point constraint, an end point constraint, a tire-in-lane constraint, a collision-free constraint, a curvature constraint, and a curvature change rate constraint;

[0039] The path planning module is used to solve the optimization objective function based on the optimization variables and the constraint conditions to determine the planned path of the truck.

[0040] In some embodiments, the linearization module is used to

[0041] Converting the overall state space equation into a curvilinear coordinate system to obtain a curvilinear state space equation;

[0042] The curve state space equation is linearized at the equilibrium point to obtain a linearized state space equation; wherein the curve state space equation is

[0043]

[0044] The linearized state space equation is:

[0045] in,

[0046] Among them, e′ y It is e y The derivative of displacement S is: yes The derivative of displacement S, β′ is the derivative of β with respect to displacement S, is the heading angle deviation between the center of the tractor's rear axle at the balance point and the matching point on the reference line, is the heading angle deviation of the trailer and tractor at the equilibrium point, is the distance between the center of the tractor's rear axle at the equilibrium point and the matching point on the reference line, is the curvature of the trajectory of the rear axle center of the tractor at the equilibrium point, Indicates the balance point.

[0047] In some embodiments, the projection determination module is used to

[0048] Determine the coordinates of the rear axle center of the tractor in the curvilinear coordinate system;

[0049] Determining the distance between the center of the rear axle of the tractor and the matching point on the reference line based on the coordinates of the center of the rear axle of the tractor in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the tractor;

[0050] Determine the coordinates of the trailer's rear axle center in the curvilinear coordinate system;

[0051] Based on the coordinates of the trailer's rear axle center in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the trailer, the distance between the trailer's rear axle center and the matching point on the reference line is determined.

[0052] In a third aspect, the present disclosure provides a computer-readable storage medium on which a truck path planning program in a curved coordinate system is stored. When the truck path planning program in the curved coordinate system is executed by a processor, the truck path planning method in the curved coordinate system described in the first aspect is implemented.

[0053] In a fourth aspect, the present disclosure provides an electronic device comprising a memory, a processor, and a truck path planning program in a curved coordinate system stored in the memory and executable on the processor. When the processor executes the truck path planning program in the curved coordinate system, the truck path planning method in the curved coordinate system described in the first aspect is implemented.

[0054] According to an embodiment of the present disclosure, a truck path planning method in a curvilinear coordinate system includes: establishing an overall state space equation of the truck, wherein the overall state space equation includes a kinematic model of a tractor and a trailer; wherein the kinematic model of the tractor and the kinematic model of the trailer are the same model; wherein the overall state space equation includes:

[0055] Where s is the displacement of the vehicle on the reference line, v is the longitudinal velocity of the vehicle along the vehicle heading direction, κ is the curvature of the driving trajectory of the center of the rear axle of the tractor, and κ r is the curvature of the vehicle at the reference line matching point, L2 is the distance from the trailer hinge point to the rear axle, d is the distance from the center of the rear axle of the migration vehicle to the hinge point, and e y is the distance between the center of the tractor's rear axle and the matching point on the reference line, is the heading angle deviation between the center of the tractor's rear axle and the matching point on the reference line, and β is the heading angle deviation between the trailer and the tractor; the overall state-space equation is converted to a curvilinear coordinate system and linearized at the equilibrium point to obtain a linearized state-space equation; based on the linearized state-space equation, the arc approximation method is used to determine the projections of the tractor and trailer on the reference line; based on the projections of the tractor and trailer on the reference line, the lateral position deviations at the centers of the rear axles of the tractor and trailer are determined respectively; an optimization problem model is established, the optimization problem model including optimization variables, an optimization objective function and constraints; wherein the optimization objective function is constructed based on the lateral position deviation at the centers of the rear axles of the tractor and trailer; the optimization variables include the lateral position deviation, heading angle deviation and curvature at the centers of the rear axles of the tractor and trailer; the constraints include at least one of the following: kinematic constraints, starting point constraints, end point constraints, tire driving within lane constraints, collision-free constraints, curvature constraints and curvature change rate constraints; based on the optimization variables and the constraints, the optimization objective function is solved for the optimization target to determine the planned path of the truck. In this application, when performing truck path planning, the overall state-space equation of the kinematic model including the tractor and trailer is used. By performing curvilinear coordinate system conversion and linearization processing on the overall state-space equation, the projections of the tractor and trailer on the reference line are determined; based on the projections of the tractor and trailer on the reference line, the lateral position deviations at the centers of the rear axles of the tractor and trailer are determined respectively to construct an optimization objective function, and then the optimization objective function is solved based on the constraints, the optimization variables are determined, and the planned path of the truck is determined, thereby effectively improving the accuracy of obstacle avoidance during path planning.

[0056] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is a flow chart of a truck path planning method in a curvilinear coordinate system according to an exemplary embodiment;

[0058] Figure 2 The figure is a schematic structural diagram of a truck path planning device in a curvilinear coordinate system according to an exemplary embodiment. DETAILED DESCRIPTION

[0059] The following describes in detail embodiments of the present disclosure, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present disclosure, and should not be construed as limiting the present disclosure.

[0060] For unmanned vehicles or manually driven vehicles that may have blind spots during driving, path planning is generally required to avoid collisions with obstacles. Related technologies include path planning methods based on search, sampling, or optimization, but these commonly used methods are generally not applicable to path planning for trailer vehicles. During path planning and obstacle avoidance, the resulting planned path is inaccurate and prone to collisions with obstacles.

[0061] In view of the above situation, the present disclosure provides a truck path planning method in a curvilinear coordinate system. Figure 1 FIG. 1 is a flow chart of a truck path planning method in a curved coordinate system according to an exemplary embodiment. Figure 1 As shown, the truck path planning method in the curvilinear coordinate system includes:

[0062] Step 10: Establish the overall state space equation of the truck, wherein the overall state space equation includes the kinematic model of the tractor and the trailer; wherein the kinematic model of the tractor and the kinematic model of the trailer are the same model; wherein the overall state space equation includes:

[0063] in, is the time derivative of the vehicle's displacement on the reference line, υ is the vehicle's longitudinal velocity along the vehicle's heading direction, κ is the curvature of the trajectory of the tractor's rear axle center, and κ r is the curvature of the vehicle at the reference line matching point, L2 is the distance from the trailer hinge point to the rear axle, d is the distance from the center of the rear axle of the migration vehicle to the hinge point, and e y is the distance between the center of the tractor's rear axle and the matching point on the reference line, is the heading angle deviation between the center of the tractor's rear axle and the matching point on the reference line, β is the heading angle deviation between the trailer and the tractor, It is e y The derivative with respect to time, yes The derivative with respect to time, is the derivative of β with respect to time;

[0064] Step 11: convert the overall state space equation into a curvilinear coordinate system and perform linearization processing at the equilibrium point to obtain a linearized state space equation;

[0065] Step 12: Based on the linearized state space equation, the projections of the tractor and trailer on the reference line are determined using a circular arc approximation method;

[0066] Step 13: Determine the lateral position deviations of the rear axle centers of the tractor and trailer respectively based on the projections of the tractor and trailer on the reference line;

[0067] Step 14: Establish an optimization problem model, wherein the optimization problem model includes optimization variables, an optimization objective function, and constraints. The optimization objective function is constructed based on the lateral position deviation at the rear axle centers of the tractor and trailer. The optimization variables include the lateral position deviation, heading angle deviation, and curvature at the rear axle centers of the tractor and trailer. The constraints include at least one of the following: a kinematic constraint, a starting point constraint, an end point constraint, a tire-in-lane constraint, a collision-free constraint, a curvature constraint, and a curvature change rate constraint.

[0068] Step 15: Based on the optimization variables and the constraints, the optimization objective function is solved to determine the planned path of the truck.

[0069] In this exemplary embodiment, when optimizing the objective function, multiple constraints such as kinematic constraints, starting point constraints, end point constraints, tire lane-travel constraints, collision-free constraints, curvature constraints, and curvature change rate constraints can be combined to optimize the objective function and solve the problem. The starting point constraints are the conditions that the tractor and trailer must meet at the start state, and the end point constraints are the conditions that the tractor and trailer must meet at the end state; the kinematic constraints are linearized state space equations; the tire lane-travel constraints are the conditions that must be met.

[0070] The non-collision constraints include the position constraints corresponding to the left front, right front, left rear, and right rear corners of the tractor, and the left rear and right rear corners of the trailer;

[0071] Curvature constraint: -K max ≤Ki≤K max ;i=0,1,2,3,…,N-2;

[0072] The curvature change rate constraint is:

[0073] -ΔK max ≤K i+1 -K i ≤ΔK max ; i = 0, 1, 2, 3, ..., N-2; where K max and ΔK max It can be calculated from the vehicle's steering characteristics. i refers to the order of the optimization variable, for example, the i-th optimization variable.

[0074] When determining the equilibrium point, two known quantities are required during planning: the starting point of planning, i.e., the vehicle's state at the start of planning; and the target lane for planning, such as the current lane or an adjacent lane. Starting from the planning start point, with the centerline of the target lane as the target, a pure tracking control algorithm is used to calculate the truck's front wheel angle. Then, using the truck's kinematic model, the truck's next state (i.e., the next path point) can be determined. Using this state as the starting point, a pure tracking algorithm and the truck's kinematic model are used to determine the state at the next next moment. This calculation, in turn, yields a path to the target lane. This path and the coordinates of the points on the target lane are used to calculate the desired equilibrium point.

[0075] In this application, when performing truck path planning, the overall state-space equation of the kinematic model including the tractor and trailer is used. By performing curvilinear coordinate system conversion and linearization processing on the overall state-space equation, the projections of the tractor and trailer on the reference line are determined; based on the projections of the tractor and trailer on the reference line, the lateral position deviations at the centers of the rear axles of the tractor and trailer are determined respectively to construct an optimization objective function, and then the optimization objective function is solved based on the constraints, the optimization variables are determined, and the planned path of the truck is determined, thereby effectively improving the accuracy of obstacle avoidance during path planning.

[0076] In some embodiments, converting the overall state-space equation into a curvilinear coordinate system and performing linearization processing at the equilibrium point to obtain a linearized state-space equation includes:

[0077] Converting the overall state space equation into a curvilinear coordinate system to obtain a curvilinear state space equation;

[0078] The curve state space equation is linearized at the equilibrium point to obtain a linearized state space equation; wherein the curve state space equation is

[0079]

[0080] The linearized state space equation is:

[0081]

[0082] Among them, e′ y It is e y The derivative of displacement S is: yes The derivative of displacement S, β′ is the derivative of β with respect to displacement S, is the heading angle deviation between the center of the tractor's rear axle at the balance point and the matching point on the reference line, is the heading angle deviation of the trailer and tractor at the equilibrium point, is the distance between the center of the tractor's rear axle at the equilibrium point and the matching point on the reference line, is the curvature of the trajectory of the rear axle center of the tractor at the equilibrium point, Indicates the balance point.

[0083] In some embodiments, determining the projections of the tractor and trailer on the reference line using a circular arc approximation method based on the linearized state-space equation includes:

[0084] Determine the coordinates of the rear axle center of the tractor in the curvilinear coordinate system;

[0085] Determining the distance between the center of the rear axle of the tractor and the matching point on the reference line based on the coordinates of the center of the rear axle of the tractor in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the tractor;

[0086] Determine the coordinates of the trailer's rear axle center in the curvilinear coordinate system;

[0087] Based on the coordinates of the trailer's rear axle center in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the trailer, the distance between the trailer's rear axle center and the matching point on the reference line is determined.

[0088] In this exemplary embodiment, since the reference line generally does not have a uniform curvature of zero, the projection of the vehicle body envelope on the reference line (sl) will be deformed. Assuming the curvature of the reference line is the same as the curvature of the tractor's rear axle center point, the reference line is bent in the opposite direction of the curvature to form a straight line, approximating the projection of the vehicle body on the reference line as an arc.

[0089] In this exemplary embodiment, the tractor projects the reference line and calculates:

[0090] The coordinates of the rear axle center of the tractor in the curvilinear coordinate system are (s, e y ), then the corresponding coordinates of the circle center are:

[0091]

[0092] The innermost and outermost arc radii of the tractor are Where ω is the width of the tractor (positive on the left and negative on the right);

[0093] W is the width of any point on the tractor body envelope, R road The radius of the reference line is a scalar, that is, a positive number;

[0094] Assume that the coordinates of the points on the vehicle body envelope are but:

[0095]

[0096] It can be deduced that:

[0097] To obtain nonlinear 2-3 through 2-1 and 2-2;

[0098] in, Is a constant, linearization is:

[0099] Taking the partial derivative of 2-4 gives 2-5:

[0100] in:

[0101]

[0102] in W i e They are the length and width of the points on the outer envelope of the car body.

[0103] Calculation of trailer projection on reference line:

[0104] Since the distance from the hinge point to the center of the rear axle of the tractor is very small compared to the size of the vehicle, we can ignore this distance and consider it to be hinged at the axle to simplify the problem. The coordinates of the center of the arc formed by the deformation of the trailer in the curvilinear coordinate system are (s, e y ), then the corresponding center coordinates are:

[0105]

[0106] The coordinates of the points on the trailer's outer envelope can be obtained by the same calculation as for the tractor:

[0107]

[0108] Linearize it to:

[0109]

[0110] in:

[0111]

[0112] In this exemplary embodiment, the optimization objective function includes:

[0113] in,

[0114] are the lateral position deviations of the rear axle centers of the tractor and trailer, respectively; J is the overall optimization objective function, where Je represents the minimum difference between the area swept by the tractor and the area swept by the trailer; J κ represents the expectation of smoothness of the planned path.

[0115] In this exemplary embodiment, solving the optimization objective function based on the optimization variables and the constraints to determine the planned path of the truck includes:

[0116] Based on the constraints, a total optimization objective function in the optimization objective function is minimized, a difference between the expected area swept by the tractor and the area swept by the trailer in the optimization objective function is minimized, and an expected smoothness of the planned path is minimized to obtain optimization variables corresponding to the constraints;

[0117] Based on the optimization variables, a planned path for the truck is determined.

[0118] The path planning algorithm designed in this application can achieve accurate obstacle collision avoidance. It can be quickly solved using an efficient numerical optimization problem solver and can be deployed on an L4 autonomous driving vehicle processor. It should be noted that the solution process involved in this application is based on conventional solution processes in the field of mathematics.

[0119] The present disclosure provides a truck path planning device in a curvilinear coordinate system. Figure 2 FIG. 1 is a schematic diagram of a truck path planning device in a curved coordinate system according to an exemplary embodiment. Figure 2 As shown, the truck path planning device in the curvilinear coordinate system includes:

[0120] The space equation building module 20 is used to build the overall state space equation of the truck, wherein the overall state space equation includes the kinematic model of the tractor and the trailer; wherein the kinematic model of the tractor and the kinematic model of the trailer are the same model; wherein the overall state space equation includes:

[0121] in, is the time derivative of the vehicle's displacement on the reference line, υ is the vehicle's longitudinal velocity along the vehicle's heading direction, κ is the curvature of the trajectory of the tractor's rear axle center, and κ r is the curvature of the vehicle at the reference line matching point, L2 is the distance from the trailer hinge point to the rear axle, d is the distance from the center of the rear axle of the migration vehicle to the hinge point, and e y is the distance between the center of the tractor's rear axle and the matching point on the reference line, is the heading angle deviation between the center of the tractor's rear axle and the matching point on the reference line, β is the heading angle deviation between the trailer and the tractor, It is e y The derivative with respect to time, yes The derivative with respect to time, is the derivative of β with respect to time;

[0122] A linearization module 21 is used to convert the overall state space equation into a curvilinear coordinate system and perform linearization processing at the equilibrium point to obtain a linearized state space equation;

[0123] a projection determination module 22 for determining the projections of the tractor and trailer on the reference line using a circular arc approximation device based on the linearized state space equation;

[0124] a position deviation determining module 23 for determining the lateral position deviations at the rear axle centers of the tractor and trailer, respectively, based on the projections of the tractor and trailer on the reference line;

[0125] A model building module 24 is configured to establish an optimization problem model, wherein the optimization problem model includes optimization variables, an optimization objective function, and constraints. The optimization objective function is constructed based on the lateral position deviation at the rear axle centers of the tractor and trailer. The optimization variables include the lateral position deviation, heading angle deviation, and curvature at the rear axle centers of the tractor and trailer. The constraints include at least one of the following: a kinematic constraint, a starting point constraint, an end point constraint, a tire-in-lane constraint, a collision-free constraint, a curvature constraint, and a curvature change rate constraint.

[0126] The path planning module 25 is used to solve the optimization objective function based on the optimization variables and the constraint conditions to determine the planned path of the truck.

[0127] In some embodiments, the linearization module is used to

[0128] Converting the overall state space equation into a curvilinear coordinate system to obtain a curvilinear state space equation;

[0129] The curve state space equation is linearized at the equilibrium point to obtain a linearized state space equation; wherein the curve state space equation is

[0130]

[0131] The linearized state space equation is:

[0132]

[0133] Among them, e′ y It is e y The derivative of displacement S is: yes The derivative of displacement S, β′ is the derivative of β with respect to displacement S, is the heading angle deviation between the center of the tractor's rear axle at the balance point and the matching point on the reference line, is the heading angle deviation of the trailer and tractor at the equilibrium point, is the distance between the center of the tractor's rear axle at the equilibrium point and the matching point on the reference line, is the curvature of the trajectory of the rear axle center of the tractor at the equilibrium point, Indicates the balance point.

[0134] In some embodiments, the projection determination module is used to

[0135] Determine the coordinates of the rear axle center of the tractor in the curvilinear coordinate system;

[0136] Determining the distance between the center of the rear axle of the tractor and the matching point on the reference line based on the coordinates of the center of the rear axle of the tractor in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the tractor;

[0137] Determine the coordinates of the trailer's rear axle center in the curvilinear coordinate system;

[0138] Based on the coordinates of the trailer's rear axle center in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the trailer, the distance between the trailer's rear axle center and the matching point on the reference line is determined.

[0139] In some embodiments, the optimization objective function includes:

[0140] in,

[0141] are the lateral position deviations of the rear axle centers of the tractor and trailer, respectively; J is the overall optimization objective function, where Je represents the minimum difference between the area swept by the tractor and the area swept by the trailer; J κ represents the expectation of smoothness of the planned path; i refers to the order of the optimization variables; K i represents the i-th curvature of the driving trajectory of the rear axle center of the tractor, K i+1 Represents the i+1th curvature of the driving trajectory of the rear axle center of the tractor.

[0142] In some embodiments, the path planning module is used to

[0143] Based on the constraints, a total optimization objective function in the optimization objective function is minimized, a difference between the expected area swept by the tractor and the area swept by the trailer in the optimization objective function is minimized, and an expected smoothness of the planned path is minimized to obtain optimization variables corresponding to the constraints;

[0144] Based on the optimization variables, a planned path for the truck is determined.

[0145] It can be understood that the truck path planning device under the curvilinear coordinate system of the present application can refer to the truck path planning method under the curvilinear coordinate system mentioned above.

[0146] The present disclosure provides a machine-readable storage medium on which a truck path planning program in a curvilinear coordinate system is stored. When the truck path planning program in a curvilinear coordinate system is executed by a processor, the truck path planning method in a curvilinear coordinate system described in the above embodiments is implemented.

[0147] The present disclosure provides an electronic device, including a memory, a processor, and a truck path planning program in a curved coordinate system stored in the memory and executable on the processor. When the processor executes the truck path planning program in the curved coordinate system, the truck path planning method in the curved coordinate system described in the above-mentioned embodiments is implemented.

[0148] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be specifically implemented in any machine-readable medium for use by an instruction execution system, device, or apparatus (such as a machine-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device, or apparatus and execute them), or in conjunction with such instruction execution systems, devices, or apparatuses. For the purposes of this specification, a "machine-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, device, or apparatus, or in conjunction with such instruction execution systems, devices, or apparatuses. More specific examples (non-exhaustive list) of machine-readable media include the following: an electrical connection portion having one or more wires (electronic device), a portable machine disk cartridge (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disc read-only memory (CDROM). Furthermore, the determining machine-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in the determining machine memory.

[0149] It should be understood that various parts of the present disclosure can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0150] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0151] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present disclosure.

[0152] In addition, the terms "first" and "second" used in the embodiments of the present disclosure are only used for descriptive purposes and should not be understood as indicating or implying relative importance, or implicitly indicating the number of technical features indicated in the embodiments. Therefore, the features defined in the embodiments of the present disclosure with terms such as "first" and "second" can explicitly or implicitly indicate that the embodiment includes at least one such feature. In the description of the present disclosure, the word "plurality" means at least two or two or more, such as two, three, four, etc., unless otherwise clearly and specifically defined in the embodiments.

[0153] In this disclosure, unless otherwise clearly specified or limited in the embodiments, the terms "installed," "connected," "connect," and "fixed" appearing in the embodiments should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection. It can also be a mechanical connection, an electrical connection, etc.; of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication between two elements, or the interaction between two elements. For those skilled in the art, the specific meanings of the above terms in this disclosure can be understood based on the specific implementation.

[0154] In the present disclosure, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0155] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A truck path planning method in a curvilinear coordinate system, characterized in that: include: Establish an overall state space equation for the truck, wherein the overall state space equation includes a kinematic model of the tractor and the trailer; wherein the kinematic model of the tractor and the kinematic model of the trailer are the same model; wherein the overall state space equation includes: in, is the time derivative of the vehicle's displacement on the reference line, υ is the vehicle's longitudinal velocity along the vehicle's heading direction, κ is the curvature of the trajectory of the tractor's rear axle center, and κ r is the curvature of the vehicle at the reference line matching point, L2 is the distance from the trailer hinge point to the rear axle, d is the distance from the center of the rear axle of the migration vehicle to the hinge point, and e y is the distance between the center of the tractor's rear axle and the matching point on the reference line, is the heading angle deviation between the center of the tractor's rear axle and the matching point on the reference line, β is the heading angle deviation between the trailer and the tractor, It is e y The derivative with respect to time, yes The derivative with respect to time, is the derivative of β with respect to time; Converting the overall state-space equation into a curvilinear coordinate system and performing linearization processing at the equilibrium point to obtain a linearized state-space equation; Based on the linearized state space equation, the projections of the tractor and trailer on the reference line are determined using a circular arc approximation method; Determining the lateral position deviations of the tractor and trailer at the rear axle centers based on the projections of the tractor and trailer on the reference line; Establishing an optimization problem model, the optimization problem model including optimization variables, an optimization objective function, and constraints; wherein the optimization objective function is constructed based on the lateral position deviation at the rear axle centers of the tractor and trailer; the optimization variables include the lateral position deviation, heading angle deviation, and curvature at the rear axle centers of the tractor and trailer; and the constraints include at least one of the following: a kinematic constraint, a starting point constraint, an end point constraint, a tire-in-lane constraint, a collision-free constraint, a curvature constraint, and a curvature change rate constraint; Based on the optimization variables and the constraints, the optimization objective function is solved to determine the planned path of the truck.

2. The truck path planning method in a curvilinear coordinate system according to claim 1, characterized in that: The overall state space equation is converted into a curvilinear coordinate system and linearized at the equilibrium point to obtain a linearized state space equation, including: Converting the overall state space equation into a curvilinear coordinate system to obtain a curvilinear state space equation; The curve state space equation is linearized at the equilibrium point to obtain a linearized state space equation; wherein the curve state space equation is: The linearized state space equation is: in, ′ Among them, e y It is e y The derivative of displacement S is: yes The derivative of displacement S, β′ is the derivative of β with respect to displacement S, is the heading angle deviation between the center of the tractor's rear axle at the balance point and the matching point on the reference line, is the heading angle deviation of the trailer and tractor at the equilibrium point, is the distance between the center of the tractor's rear axle at the equilibrium point and the matching point on the reference line, is the curvature of the trajectory of the rear axle center of the tractor at the equilibrium point, Indicates the balance point.

3. The truck path planning method in a curvilinear coordinate system according to claim 1, characterized in that: The method of determining the projections of the tractor and the trailer on the reference line by using a circular arc approximation method based on the linearized state space equation includes: Determine the coordinates of the rear axle center of the tractor in the curvilinear coordinate system; Determining the distance between the center of the rear axle of the tractor and the matching point on the reference line based on the coordinates of the center of the rear axle of the tractor in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the tractor; Determine the coordinates of the trailer's rear axle center in the curvilinear coordinate system; Based on the coordinates of the trailer's rear axle center in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the trailer, the distance between the trailer's rear axle center and the matching point on the reference line is determined.

4. The truck path planning method in a curvilinear coordinate system according to claim 1, characterized in that: The optimization objective function includes: in, are the lateral position deviations of the rear axle centers of the tractor and trailer, respectively; J is the overall optimization objective function, where Je represents the minimum difference between the area swept by the tractor and the area swept by the trailer; J κ represents the expectation of smoothness of the planned path; i refers to the order of the optimization variables; K i represents the i-th curvature of the driving trajectory of the rear axle center of the tractor, K i+1 Represents the i+1th curvature of the driving trajectory of the rear axle center of the tractor.

5. The truck path planning method in a curvilinear coordinate system according to claim 4, characterized in that: The step of solving the optimization objective function based on the optimization variables and the constraint conditions to determine the planned path of the truck includes: Based on the constraints, a total optimization objective function in the optimization objective function is minimized, a difference between the expected area swept by the tractor and the area swept by the trailer in the optimization objective function is minimized, and an expected smoothness of the planned path is minimized to obtain optimization variables corresponding to the constraints; Based on the optimization variables, a planned path for the truck is determined.

6. A truck path planning device in a curvilinear coordinate system, characterized in that: include: space An equation building module is used to build an overall state space equation of the truck, wherein the overall state space equation includes a kinematic model of the tractor and the trailer; wherein the kinematic model of the tractor and the kinematic model of the trailer are the same model; wherein the overall state space equation includes: in, is the time derivative of the vehicle's displacement on the reference line, υ is the vehicle's longitudinal velocity along the vehicle's heading direction, κ is the curvature of the trajectory of the tractor's rear axle center, and κ r is the curvature of the vehicle at the reference line matching point, L2 is the distance from the trailer hinge point to the rear axle, d is the distance from the center of the rear axle of the migration vehicle to the hinge point, and e y is the distance between the center of the tractor's rear axle and the matching point on the reference line, is the heading angle deviation between the center of the tractor's rear axle and the matching point on the reference line, β is the heading angle deviation between the trailer and the tractor, It is e y The derivative with respect to time, yes The derivative with respect to time, is the derivative of β with respect to time; A linearization module, configured to convert the overall state-space equation into a curvilinear coordinate system and perform linearization processing at the equilibrium point to obtain a linearized state-space equation; a projection determination module for determining the projections of the tractor and trailer on the reference line using a circular arc approximation device based on the linearized state space equation; a position deviation determining module for determining lateral position deviations at the rear axle centers of the tractor and trailer, respectively, based on projections of the tractor and trailer on a reference line; a model building module for building an optimization problem model, the optimization problem model including optimization variables, an optimization objective function, and constraints; wherein the optimization objective function is constructed based on the lateral position deviation at the rear axle centers of the tractor and trailer; the optimization variables include the lateral position deviation, heading angle deviation, and curvature at the rear axle centers of the tractor and trailer; and the constraints include at least one of the following: a kinematic constraint, a starting point constraint, an end point constraint, a tire-in-lane constraint, a collision-free constraint, a curvature constraint, and a curvature change rate constraint; The path planning module is used to solve the optimization objective function based on the optimization variables and the constraint conditions to determine the planned path of the truck.

7. The truck path planning device in a curvilinear coordinate system according to claim 6, characterized in that: The linearization module is used to Converting the overall state space equation into a curvilinear coordinate system to obtain a curvilinear state space equation; The curve state space equation is linearized at the equilibrium point to obtain a linearized state space equation; wherein the curve state space equation is The linearized state space equation is: in, ′ Among them, e y It is e y The derivative of displacement S is: yes The derivative of displacement S, β′ is the derivative of β with respect to displacement S, is the heading angle deviation between the center of the tractor's rear axle at the balance point and the matching point on the reference line, is the heading angle deviation of the trailer and tractor at the equilibrium point, is the distance between the center of the tractor's rear axle at the equilibrium point and the matching point on the reference line, is the curvature of the trajectory of the rear axle center of the tractor at the equilibrium point, Indicates the balance point.

8. The truck path planning device in a curvilinear coordinate system according to claim 7, characterized in that: The projection determination module is used to Determine the coordinates of the rear axle center of the tractor in the curvilinear coordinate system; Determining the distance between the center of the rear axle of the tractor and the matching point on the reference line based on the coordinates of the center of the rear axle of the tractor in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the tractor; Determine the coordinates of the trailer's rear axle center in the curvilinear coordinate system; Based on the coordinates of the trailer's rear axle center in the curvilinear coordinate system and the radii of the innermost and outermost arcs of the trailer, the distance between the trailer's rear axle center and the matching point on the reference line is determined.

9. A computer-readable storage medium, characterized in that A truck path planning program in a curvilinear coordinate system is stored thereon. When the truck path planning program in a curvilinear coordinate system is executed by a processor, the truck path planning method in a curvilinear coordinate system according to any one of claims 1 to 5 is implemented.

10. An electronic device, characterized in that: The invention comprises a memory, a processor and a truck path planning program in a curved coordinate system stored in the memory and executable on the processor. When the processor executes the truck path planning program in the curved coordinate system, the truck path planning method in the curved coordinate system according to any one of claims 1 to 5 is implemented.

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