Vehicle control method

Abstract

The invention provides a vehicle control method which comprises the following steps: respectively constructing a trajectory tracking controller and a stability controller based on a longitudinal, lateral and yaw three-degree-of-freedom dynamic model of a vehicle; identifying whether the vehicle is in an unstable state; in response to the situation that the vehicle is not in the unstable state, disabling a vehicle control function of a stability controller, and controlling the vehicle through a trajectory tracking controller; in response to the vehicle being in the unstable state, the vehicle is controlled by a trajectory tracking controller and a stability controller. According to the scheme, compared with a two-degree-of-freedom vehicle model, the influence of the longitudinal vehicle speed on the yaw velocity and the transverse velocity in the emergency braking and steering working condition process can be better represented, and meanwhile, in the emergency braking and steering process, when trajectory tracking and stability control jointly act on the vehicle chassis, the motion characteristics of the whole vehicle are improved; and through a designed coordination control strategy, the outputs of the two controllers are properly adjusted, so that the stability of the vehicle can be ensured while the trajectory tracking precision is improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of vehicle dynamics control, and in particular to a vehicle control method. Background Art

[0002] The vehicle motion control problem is one of the core technologies of intelligent driving. Vehicle motion control is mainly divided into two aspects: lateral and longitudinal. Longitudinal control mainly solves the tracking of target displacement and target speed. Typical longitudinal control systems include Adaptive Cruise Control (ACC) system and Autonomous Emergency Braking (AEB) system. The lateral control is mainly reflected in trajectory tracking and vehicle yaw stability control. Among them, vehicle yaw stability control has a relatively mature application in traditional cars. It can provide additional yaw torque to the vehicle through active steering or differential braking, thereby ensuring stable driving of the vehicle. Intelligent car trajectory tracking requires simultaneous control of the longitudinal and lateral motion of the vehicle to accurately track the target trajectory. Summary of the invention

[0003] The present disclosure aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, an object of the present disclosure is to provide a vehicle control method.

[0005] A second objective of the present disclosure is to provide a vehicle control device.

[0006] A third objective of the present disclosure is to provide an electronic device.

[0007] A fourth object of the present disclosure is to provide a non-transitory computer-readable storage medium.

[0008] A fifth object of the present disclosure is to provide a computer program product.

[0009] To achieve the above-mentioned purpose, the first aspect of the present disclosure proposes a vehicle control method, including: based on the three-degree-of-freedom dynamic model of the vehicle's longitudinal, lateral and yaw, respectively constructing a trajectory tracking controller and a stability controller for the vehicle; identifying whether the vehicle is in an unstable state; in response to the vehicle not being in an unstable state, disabling the vehicle control function of the stability controller, and controlling the vehicle through the trajectory tracking controller; in response to the vehicle being in an unstable state, activating the vehicle control function of the stability controller, and controlling the vehicle through the trajectory tracking controller and the stability controller.

[0010] According to one embodiment of the present disclosure, after controlling the vehicle through the trajectory tracking controller and the stability controller, it also includes: in response to the center of mass sideslip angle of the vehicle being less than a first set value, and the center of mass sideslip angular velocity of the vehicle being less than a second set value, disabling the vehicle control function of the stability controller, and controlling the vehicle through the trajectory tracking controller.

[0011] According to one embodiment of the present disclosure, after controlling the vehicle through the trajectory tracking controller and the stability controller, it also includes: in response to the center of mass sideslip angle being greater than or equal to a first set value, and / or the center of mass sideslip angular velocity being greater than or equal to a second set value, re-identifying whether the vehicle is in an unstable state; in response to the vehicle not being in an unstable state, disabling the vehicle control function of the stability controller, and controlling the vehicle through the trajectory tracking controller.

[0012] According to one embodiment of the present disclosure, after re-identifying whether the vehicle is in an unstable state, it also includes: in response to the vehicle being in an unstable state, maintaining the vehicle control function of the stability controller in an activated state, and continuing to control the vehicle through the trajectory tracking controller and the stability controller.

[0013] According to one embodiment of the present disclosure, controlling the vehicle by the trajectory tracking controller and the stability controller includes: inputting a first state quantity of the vehicle into the trajectory tracking controller, and outputting a first control quantity of the vehicle by the trajectory tracking controller; inputting a second state quantity of the vehicle into the stability controller, and outputting a second control quantity of the vehicle by the stability controller; and controlling the vehicle based on the first control quantity and the second control quantity.

[0014] According to one embodiment of the present disclosure, controlling the vehicle based on the first control amount and the second control amount includes: determining a target control amount of the vehicle from the first control amount and the second control amount to control the vehicle; and / or fusing the first control amount and the second control amount to obtain the target control amount to control the vehicle.

[0015] According to one embodiment of the present disclosure, determining the target control amount of the vehicle from the first control amount and the second control amount includes: taking the equivalent longitudinal force of the vehicle in the first control amount, and the front wheel turning angle and additional yaw moment of the vehicle in the second control amount as the target control amount.

[0016] According to one embodiment of the present disclosure, each type of state quantity includes the longitudinal velocity, lateral velocity and yaw rate of the vehicle.

[0017] According to one embodiment of the present disclosure, the second state quantity of the vehicle is input into the stability controller, and the stability controller outputs the first front wheel steering angle and the additional yaw moment of the vehicle, including: adding the equivalent control force of the vehicle to the disturbance quantity of the stability controller; inputting the second state quantity of the vehicle and the disturbance quantity of the stability controller into the stability controller, and the stability controller outputs the first front wheel steering angle and the additional yaw moment.

[0018] According to one embodiment of the present disclosure, the three-degree-of-freedom dynamic model based on the longitudinal, lateral and yaw of the vehicle respectively constructs the trajectory tracking controller and the stability controller of the vehicle, including: constructing a trajectory tracking kinematic error model of the vehicle; constructing the trajectory tracking controller based on the three-degree-of-freedom dynamic model and the trajectory tracking kinematic error model.

[0019] To achieve the above-mentioned purpose, the second aspect embodiment of the present disclosure proposes a vehicle control device, including: a construction module, used to construct a trajectory tracking controller and a stability controller of the vehicle based on the three-degree-of-freedom dynamic model of the longitudinal, lateral and yaw of the vehicle, respectively; an identification module, used to identify whether the vehicle is in an unstable state; a first control module, used to disable the vehicle control function of the stability controller in response to the vehicle not being in an unstable state, and control the vehicle through the trajectory tracking controller; a second control module, used to activate the vehicle control function of the stability controller in response to the vehicle being in an unstable state, and control the vehicle through the trajectory tracking controller and the stability controller.

[0020] To achieve the above-mentioned purpose, the third aspect embodiment of the present disclosure proposes an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to implement the vehicle control method as described in the first aspect embodiment of the present disclosure.

[0021] To achieve the above-mentioned purpose, the fourth aspect embodiment of the present disclosure proposes a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to implement the vehicle control method as described in the first aspect embodiment of the present disclosure.

[0022] To achieve the above-mentioned purpose, the fifth aspect of the present disclosure proposes a computer program product, including a computer program, which is used to implement the vehicle control method as described in the first aspect of the present disclosure when executed by a processor.

[0023] Therefore, the vehicle's lateral and longitudinal coupling characteristics can be overcome through the disclosed solution. The stability controller and the trajectory tracking controller are generated through a three-degree-of-freedom dynamic model. Compared with the two-degree-of-freedom vehicle model, the three-degree-of-freedom model can better characterize the influence of the longitudinal vehicle speed on the yaw angular velocity and lateral velocity during emergency braking and steering conditions due to the addition of the longitudinal vehicle speed. At the same time, during the emergency braking and steering process, the motion characteristics of the entire vehicle when trajectory tracking and stability control work together on the vehicle chassis, through the designed coordinated control strategy, the outputs of the two controllers are appropriately adjusted, which can improve the accuracy of trajectory tracking while ensuring the stability of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of a vehicle control method according to an embodiment of the present disclosure;

[0025] Figure 2 is a schematic diagram of a trajectory tracking kinematic error model according to an embodiment of the present disclosure;

[0026] Figure 3 is a schematic diagram of another vehicle control method according to an embodiment of the present disclosure;

[0027] Figure 4 is a schematic diagram of another vehicle control method according to an embodiment of the present disclosure;

[0028] Figure 5 is a schematic diagram of a vehicle control device according to one embodiment of the present disclosure;

[0029] Figure 6 is a schematic diagram of an electronic device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] Embodiments of the present disclosure are described in detail below, 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.

[0031] The acquisition, storage, use, and processing of data in the technical solution disclosed in this disclosure are in compliance with the relevant provisions of relevant laws and regulations.

[0032] It should be noted that in the embodiments of the present application, certain software, components, models and other existing solutions in the industry may be mentioned, and they should be considered as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0033] Figure 1is a schematic diagram of a vehicle control method according to an embodiment of the present disclosure, such as Figure 1 As shown, the vehicle control method includes the following steps:

[0034] S101, based on the three-degree-of-freedom dynamic model of the vehicle, the trajectory tracking controller and the stability controller of the vehicle are respectively constructed.

[0035] The vehicle control method of the embodiment of the present application can be applied to the scenario of vehicle dynamics control. The executor of the vehicle control of the embodiment of the present application can be the vehicle control device of the embodiment of the present application, and the vehicle control device can be set on an electronic device.

[0036] It should be noted that the main task of the trajectory tracking controller is to enable the vehicle to drive along a predetermined path or trajectory. This controller is usually used in autonomous driving systems to ensure that the vehicle can drive safely and accurately in complex road environments.

[0037] The stability controller is designed to maintain the dynamic stability of the vehicle and prevent loss of control due to oversteer, understeer or other reasons.

[0038] In current technology, the two-degree-of-freedom dynamics model is mainly used to calculate and predict the vehicle posture. The two-degree-of-freedom dynamics model of a vehicle is a simplified vehicle dynamics model, which is mainly used to analyze and study the dynamic behavior of a car in lateral motion. This model assumes that the vehicle moves only in two directions: longitudinal (along the direction of travel) and lateral (perpendicular to the direction of travel). However, in the two-degree-of-freedom dynamics model, only lateral motion and yaw motion are usually considered, so it is actually modeled for these two degrees of freedom.

[0039] The inventors of the present disclosure propose a three-degree-of-freedom dynamics model, and select the three-degree-of-freedom vehicle model as the vehicle dynamics model of the trajectory tracking controller and the stability controller as follows. In addition, compared with two degrees of freedom, the addition of longitudinal vehicle speed will greatly increase the nonlinear characteristics of the model. In a possible implementation method, the three-degree-of-freedom dynamics model can be simplified to the following form:

[0040]

[0041] Among them, v hx is the longitudinal velocity of the vehicle; v hy is the lateral velocity of the vehicle; ω is the yaw angular velocity of the vehicle; F ux-tra is the equivalent longitudinal force of the vehicle; C f and C r are the front and rear wheel cornering stiffness respectively; l fand l r are the distances from the center of mass to the front and rear axes respectively; δ f-tra is the front wheel turning angle; β is the sideslip angle of the center of mass.

[0042] In the disclosed embodiment, after the three-degree-of-freedom dynamics model is obtained, the trajectory tracking controller and stability controller of the vehicle can be established according to the three-degree-of-freedom dynamics model. The establishment method can be various, and no limitation is made here. In one possible implementation method, the data generated by the three-degree-of-freedom dynamics model and the data generated by the actual vehicle can be compared and processed, and the trajectory tracking controller and stability controller of the vehicle can be constructed according to the comparison results and the processing results.

[0043] In another possible implementation, a trajectory tracking controller can be constructed by constructing a trajectory tracking kinematic error model of the vehicle and then based on the three-degree-of-freedom dynamics model and the trajectory tracking kinematic error model. Both the trajectory tracking controller and the stability controller are composed of at least two control modules among quasi-steady-state control, feedforward control, and error feedback control. For example, Figure 2 As shown in , after obtaining the simplified three-degree-of-freedom vehicle dynamics model, a trajectory tracking model is established to obtain the actual tracking error for controller design. Figure 2 The figure shows a schematic diagram of the trajectory tracking kinematic error model, where the actual center of mass position of the intelligent vehicle is P1, the center of mass position of the target matching point given by the trajectory planning layer is P3, and P2 is the projection point of the normal along the desired velocity at P3 in the longitudinal velocity direction at P1.

[0044] according to Figure 2 The geometric relationship in can be used to obtain the trajectory tracking error model as follows:

[0045]

[0046] In the formula, x e represents the longitudinal tracking error, y e represents the lateral tracking error, and denote the actual and expected yaw angles of the vehicle, respectively, e represents the error between the desired yaw angle and the actual yaw angle of the vehicle, v xd and ω d They represent the desired longitudinal speed and yaw rate of the vehicle, respectively, and R p Represents the road curvature of the target trajectory.

[0047] The rotation matrix of the vehicle posture error from the earth coordinate system to the vehicle coordinate system can be expressed as:

[0048]

[0049] In the formula, X, Y, X d ,Y d They represent the actual position coordinates of the vehicle and the target matching point coordinates in the geodetic coordinate system respectively.

[0050] The three-degree-of-freedom dynamics model is introduced into the trajectory tracking error model to obtain the lateral and longitudinal coupled trajectory tracking dynamics error model, which is converted into the state space equation form as follows:

[0051]

[0052]

[0053] y G =x G1 (10)

[0054] In the formula, x G1 =[x e y e ] T , y G =[F ux-tra δ f-tra ] T ,

[0055] F1(x G1 )=0 2×1 , G1(x G1 )=I 2×2 , P1=[ρ1ρ2ρ4ρ5] T and P2=[ρ3ρ6] T is the changing parameter matrix, where ρ oi represents the model reference value obtained through calibration experiments, It represents the change value of the real parameters of the vehicle system, and its value can be obtained through the inherent parameters of the vehicle.

[0056] f 2,1 (x G1 ), g 2,1 (x G1 )、f2(x Gq )、g2(x G1 ) are respectively represented as follows:

[0057] f2(x G1 )=[f 2,2 (x G1 )f 2,3 (x G1 )f 2,4 (x G1 )f 2,5(x G1 )] T ,

[0058]

[0059]

[0060] The error model state space equation output is rewritten as follows

[0061]

[0062]

[0063] In the formula, B g (x G1 )=G1(x G1 )G2(x G1 ), C G (x G1 )=G1(x G1 )F2(x G1 ).

[0064] Next, the trajectory tracking control rate is designed based on the model. The control rate of the present invention mainly consists of two parts, namely, quasi-steady-state control and state error feedback control, and its mathematical expression is as follows:

[0065] u trajectory =u s_trajectory +u e_trajectory (13)

[0066] Among them, u trajectory is the control rate, x s_trajectory For quasi-steady-state control, x e_trajectory It is the state error feedback control.

[0067] First, design a quasi-steady-state feedback control law. The most common method in steady-state control is the table lookup method. A map table can be flexibly made according to the controlled target, but the calibration process of the map table is very time-consuming. Therefore, the quasi-steady-state idea is used. It is assumed that the control output when the system is already in a balanced state is used to quickly adjust the system to be near the control equilibrium point. The most ideal situation for the trajectory tracking control system is that both the lateral error and the longitudinal error are 0, so let the expected tracking value of the trajectory tracking output be y Gd =[0 0] T , in order to obtain a class steady-state map table, let Substituting it into formula (12) we can obtain the quasi-steady-state control law u s :

[0068]

[0069] Due to the simplification of the vehicle model and the lack of consideration of the influence of external disturbances, the real trajectory tracking system has unmodeled dynamics and external disturbances. Therefore, only the steady-state control rate cannot completely eliminate the system tracking error. In order to further adjust the system to make it track the target trajectory stably and quickly, a state error feedback control link is added, and an error feedback control law is designed. The following error of the trajectory tracking closed-loop system is defined as e G1 =y Gd -y G , the design error feedback control rate is

[0070]

[0071] At this point, the complete nonlinear trajectory tracking controller system control law u is obtained G for:

[0072]

[0073] Next, the design process of the stability controller is introduced in detail. When the vehicle is turning in emergency braking, the longitudinal force and front wheel steering angle output by the trajectory tracking controller acting on the chassis system may exceed the tire adhesion ellipse, thus failing to ensure the stability of the vehicle. In order to achieve the goal of maintaining the vehicle's stability without losing too much trajectory tracking accuracy, it is necessary to correct the vehicle's steering wheel angle δ stable And provide additional yaw moment T uz-S To help the vehicle track the steady-state yaw rate of the target, the three-degree-of-freedom vehicle dynamics model can be updated as follows:

[0074]

[0075]

[0076]

[0077] Select the vehicle longitudinal velocity v hx , lateral speed v hy and yaw angular velocity ω as the state variables of the stability control system, let x stable =[v hx ,v hy ,ω] T ; δ stable and T uz-S As the control input of the stability control system, let u stable =[δ stable ,T stable ] T The goal of the control system is to track the target longitudinal velocity v xd , target lateral velocity v ydand the target steady-state yaw angular velocity ω d_stavle , let the target state x target =[v xd ,v yd ,ω d_stable ] T , where v xd It can be obtained according to the trajectory tracking error model, In steady state, the relationship between the target lateral acceleration and the target yaw rate is a yd =v·ω d_stable ; Equivalent longitudinal force F of trajectory tracking input ux-tra As the input disturbance of the stability control system, that is, w = F ux-tra The updated three-degree-of-freedom dynamic equation is rewritten into the state space equation form as follows:

[0078]

[0079] y stable =C stable x stable (twenty one)

[0080] In the formula,

[0081] Next, the vehicle stability control rate is designed based on the updated model. The stability control rate consists of three parts: quasi-steady-state control, feedforward control, and feedback control. Its mathematical expression is as follows:

[0082] u stable =u stable_s +u stable_f +u stable_e (twenty two)

[0083] First, the quasi-steady-state control u s_stable , let the system state Existence stable_s =[δ stable_s ,T stable_s ] T Satisfying formula (23):

[0084]

[0085] Therefore, the quasi-steady-state control rate can be derived as follows:

[0086]

[0087] For a complex system, only quasi-steady-state control can keep it near the system stability point, but the accuracy cannot meet the control requirements. Therefore, reference feedforward control is introduced so that the system can respond quickly when the reference dynamics changes. Let the reference dynamic feedforward control rate u f_stable =[δ stable_f ,T stable_f ] T Satisfying formula (25):

[0088]

[0089] According to the target state setting, Combining formula (23), f(x stable )+B stable u stable_s +B s w=0, we can get Therefore, the specific form of the reference dynamic feedforward control rate can be obtained as follows:

[0090]

[0091] Due to the interference, parameter uncertainty, delay and other factors in the real system, the mathematical model of the system cannot fully represent the real system characteristics, so it is necessary to introduce error feedback control to correct the impact of the difference between the model and the real system. The tracking error of the system is defined as:

[0092]

[0093] Introducing error feedback control rate u stable_e =[δ stable_e ,T stable_e ] T , so that it satisfies:

[0094]

[0095] The errors of the vehicle's longitudinal velocity, lateral velocity, and yaw rate are defined as: e ω =ω-ω d_stable According to formula (27), the derivative of the system tracking error can be obtained:

[0096]

[0097] Substituting equation (24) and equation (26) into equation (29), we can get the specific form of the system state variable error as follows:

[0098]

[0099] Assume that the stability tracking error feedback control rate has the form of state feedback:

[0100]

[0101] Substituting formula (31) into formula (30) yields:

[0102]

[0103] Where:

[0104] Solve the characteristic equation of the matrix |λI-z|=0. As long as the eigenvalue λ of the matrix satisfies λ i (z)<0,i=1,2,3, then the system is stable.

[0105] Since the system is a second-order system, λ i (z)<0,i=1,2,3 is equivalent to: ①λ1+λ2+λ3<0; ②λ1·λ2·λ3>0

[0106] Therefore, as long as appropriate m1, m2, m3, m4, m5, and m6 are selected to meet the above conditions, the stability error feedback control rate u can be obtained. stable_e .

[0107] S102, identifying whether the vehicle is in an unstable state.

[0108] Vehicle instability refers to the situation where the vehicle cannot maintain the expected driving trajectory or posture under certain driving conditions, resulting in loss of control. This situation may be caused by a variety of factors, including but not limited to driver error, poor road conditions, vehicle design defects or system failures.

[0109] In the embodiments of the present disclosure, there may be multiple methods for identifying whether the vehicle is in an unstable state. In one possible implementation, the method may be determined by collecting and analyzing data through vehicle sensors. The vehicle sensors may be multiple, and no limitation is made here. For example, the vehicle sensors may include one or more of a yaw rate sensor, a wheel speed sensor, and a steering wheel angle sensor.

[0110] In another possible implementation, the vehicle's driving data may be processed or predicted based on a trained model or system to determine whether the vehicle is currently in an unstable state. The model or system may be an electronic stability control system, an anti-lock braking system, or the like.

[0111] S103 , in response to the vehicle not being in an unstable state, disabling a vehicle control function of a stability controller, and controlling the vehicle through a trajectory tracking controller.

[0112] S104 , in response to the vehicle being in an unstable state, activating a vehicle control function of a stability controller, and controlling the vehicle through a trajectory tracking controller and a stability controller.

[0113] In the disclosed embodiment, firstly, based on the longitudinal, lateral and yaw three-degree-of-freedom dynamics model of the vehicle, the trajectory tracking controller and the stability controller of the vehicle are respectively constructed, and then it is identified whether the vehicle is in an unstable state. In response to the vehicle not being in an unstable state, the vehicle control function of the stability controller is disabled, and the vehicle is controlled by the trajectory tracking controller. In response to the vehicle being in an unstable state, the vehicle control function of the stability controller is activated, and the vehicle is controlled by the trajectory tracking controller and the stability controller. Thus, the vehicle's lateral and longitudinal coupling characteristics can be overcome through the disclosed scheme. The stability controller and the trajectory tracking controller are generated through the three-degree-of-freedom dynamics model. Compared with the two-degree-of-freedom vehicle model, the three-degree-of-freedom can better characterize the influence of the longitudinal vehicle speed on the yaw angular velocity and the lateral velocity during the emergency braking and steering process due to the addition of the longitudinal vehicle speed. At the same time, the motion characteristics of the whole vehicle when the trajectory tracking and stability control work together on the vehicle chassis during the emergency braking and steering process of this scheme, through the designed coordinated control strategy, the outputs of the two controllers are appropriately adjusted, which can improve the accuracy of trajectory tracking while ensuring the stability of the vehicle.

[0114] In the above embodiment, after the vehicle is controlled by the trajectory tracking controller and the stability controller, the following steps are also included: Figure 3 As shown:

[0115] S301, in response to a vehicle's center of mass sideslip angle being less than a first set value and a vehicle's center of mass sideslip angular velocity being less than a second set value, disabling a vehicle control function of a stability controller and controlling the vehicle through a trajectory tracking controller.

[0116] It should be noted that the vehicle's center of mass slip angle refers to the angle between the velocity direction at the center of mass of the vehicle and the longitudinal axis of the vehicle. In other words, it is the difference between the actual direction of the vehicle and the direction of its front. The center of mass slip angle is one of the important parameters for evaluating the dynamic behavior of the vehicle, especially when the vehicle is turning, sliding or losing control. The vehicle's center of mass slip angular velocity refers to the rate of change of the vehicle's center of mass slip angle over time.

[0117] When an intelligent vehicle encounters a strong lateral and longitudinal coupling condition such as high-speed emergency turning and braking, the lateral and longitudinal forces of the tires are often close to the boundaries of the tire force attachment ellipse. At this time, the vehicle is very likely to be transiently laterally unstable due to interference from some external conditions. If the trajectory tracking still maintains the original control output after the stability controller intervenes at this time, the two controllers acting on the longitudinal and lateral movements of the vehicle at the same time will inevitably lead to control conflicts, resulting in the inability to track the target trajectory and even the risk of rollover. In order to solve the above problems, the disclosed solution proposes a first set value and a second set value to determine the current state of the vehicle and calibrate which control strategy to adopt.

[0118] It should be noted that the first set value and the second set value are stability boundary coefficients, which are designed in advance and can be changed according to the vehicle parameters and operating parameters of the actual vehicle, and no limitation is made here.

[0119] S302: In response to a center-of-mass sideslip angle being greater than or equal to a first set value, and / or a center-of-mass sideslip angle velocity being greater than or equal to a second set value, re-identify whether the vehicle is in an unstable state.

[0120] In the disclosed embodiment, in response to the center of mass slip angle being greater than or equal to the first set value, and / or the center of mass slip angle velocity being greater than or equal to the second set value, it indicates that the vehicle may have changed from an unstable state to a stable state, or the previous judgment that the vehicle is in an unstable state is wrong. It is necessary to re-identify whether the vehicle is in an unstable state.

[0121] S303 , in response to the vehicle not being in an unstable state, disabling a vehicle control function of a stability controller, and controlling the vehicle through a trajectory tracking controller.

[0122] In the disclosed embodiment, in response to the vehicle's center of mass slip angle being less than a first set value, and the vehicle's center of mass slip angular velocity being less than a second set value, the vehicle control function of the stability controller is disabled, and the vehicle is controlled by a trajectory tracking controller; or in response to the center of mass slip angle being greater than or equal to the first set value, and / or the center of mass slip angular velocity being greater than or equal to the second set value, it is re-identified whether the vehicle is in an unstable state, and in response to the vehicle not being in an unstable state, the vehicle control function of the stability controller is disabled, and the vehicle is controlled by a trajectory tracking controller. This intelligent control strategy based on the center of mass slip angle and the center of mass slip angular velocity not only improves the safety of the vehicle, but also improves the driving experience and the efficiency of the entire control system. It ensures optimal performance under various driving conditions through a reasonable controller switching mechanism, thereby providing the driver with a safer and more comfortable driving environment.

[0123] It should be noted that after re-identifying whether the vehicle is in an unstable state, in response to the vehicle being in an unstable state, the vehicle control function of the stability controller is maintained in an activated state, and the vehicle continues to be controlled by the trajectory tracking controller and the stability controller.

[0124] In the above embodiment, the vehicle is controlled by the trajectory tracking controller and the stability controller. Figure 4 Explaining further, the method includes:

[0125] S401, inputting a first state variable of the vehicle into a trajectory tracking controller, and the trajectory tracking controller outputs a first control variable of the vehicle.

[0126] S402, inputting a second state variable of the vehicle into a stability controller, and the stability controller outputs a second control variable of the vehicle.

[0127] It should be noted that the first state quantity and the second state quantity both include the longitudinal velocity, lateral velocity and yaw angular velocity of the vehicle.

[0128] In the embodiment of the present disclosure, the first control variable is the equivalent longitudinal force F ux-tra Still given by the trajectory tracking controller, the second state quantity is the modified front wheel steering angle δ stable , and the additional yaw moment T stable .

[0129] In the disclosed embodiment, the equivalent control force of the vehicle can be added to the disturbance amount of the stability controller, and then the second state amount of the vehicle and the disturbance amount of the stability controller are input into the stability controller, and the stability controller outputs the first front wheel steering angle and the additional yaw moment.

[0130] S403, controlling the vehicle based on the first control amount and the second control amount.

[0131] In the embodiment of the present disclosure, the target control amount of the vehicle can be determined from the first control amount and the second control amount to control the vehicle, or the first control amount and the second control amount can be fused to obtain the target control amount to control the vehicle.

[0132] In the embodiment of the present disclosure, there may be multiple methods for fusing the first control amount and the second control amount, which are not limited here. In one possible implementation, the first control amount and the second control amount may be processed by a fusion processing algorithm to calculate the target control amount. In another possible implementation, the first control amount and the second control amount may also be processed by a fusion model to output the target control amount.

[0133] In the embodiment of the present disclosure, the target control amount of the vehicle is determined from the first control amount and the second control amount. The equivalent longitudinal force of the vehicle in the first control amount, and the front wheel angle and additional yaw moment of the vehicle in the second control amount can be used as the target control amount.

[0134] Corresponding to the vehicle control methods provided in the above-mentioned embodiments, an embodiment of the present disclosure also provides a vehicle control device. Since the vehicle control device provided in the embodiment of the present disclosure corresponds to the vehicle control methods provided in the above-mentioned embodiments, the implementation methods of the above-mentioned vehicle control methods are also applicable to the vehicle control devices provided in the embodiments of the present disclosure and will not be described in detail in the following embodiments.

[0135] Figure 5 is a schematic diagram of a vehicle control device according to an embodiment of the present disclosure, such as Figure 5 As shown, the vehicle control device 500 includes: a construction module 510, an identification module 520, a first control module 530 and a second control module 540.

[0136] The construction module 510 is used to construct a trajectory tracking controller and a stability controller of the vehicle based on the three-degree-of-freedom dynamic model of the longitudinal, lateral and yaw directions of the vehicle.

[0137] The identification module 520 is used to identify whether the vehicle is in an unstable state.

[0138] The first control module 530 is configured to disable the vehicle control function of the stability controller and control the vehicle through the trajectory tracking controller in response to the vehicle not being in an unstable state.

[0139] The second control module 540 is configured to activate the vehicle control function of the stability controller in response to the vehicle being in an unstable state, and control the vehicle through the trajectory tracking controller and the stability controller.

[0140] According to one embodiment of the present disclosure, after controlling the vehicle through the trajectory tracking controller and the stability controller, it also includes: in response to the vehicle's center of mass sideslip angle being less than a first set value and the vehicle's center of mass sideslip angular velocity being less than a second set value, disabling the vehicle control function of the stability controller, and controlling the vehicle through the trajectory tracking controller.

[0141] According to one embodiment of the present disclosure, after controlling the vehicle through the trajectory tracking controller and the stability controller, it also includes: in response to the center of mass sideslip angle being greater than or equal to a first set value, and / or the center of mass sideslip angular velocity being greater than or equal to a second set value, re-identifying whether the vehicle is in an unstable state; in response to the vehicle not being in an unstable state, disabling the vehicle control function of the stability controller, and controlling the vehicle through the trajectory tracking controller.

[0142] According to one embodiment of the present disclosure, after re-identifying whether the vehicle is in an unstable state, it also includes: in response to the vehicle being in an unstable state, maintaining the vehicle control function of the stability controller in an activated state, and continuing to control the vehicle through the trajectory tracking controller and the stability controller.

[0143] According to one embodiment of the present disclosure, a vehicle is controlled by a trajectory tracking controller and a stability controller, including: inputting a first state quantity of the vehicle into the trajectory tracking controller, and the trajectory tracking controller outputting a first control quantity of the vehicle; inputting a second state quantity of the vehicle into the stability controller, and the stability controller outputting a second control quantity of the vehicle; and controlling the vehicle based on the first control quantity and the second control quantity.

[0144] According to one embodiment of the present disclosure, a vehicle is controlled based on a first control amount and a second control amount, including: determining a target control amount of the vehicle from the first control amount and the second control amount to control the vehicle; and / or fusing the first control amount and the second control amount to obtain a target control amount to control the vehicle.

[0145] According to one embodiment of the present disclosure, a target control amount of a vehicle is determined from a first control amount and a second control amount, including: taking the equivalent longitudinal force of the vehicle in the first control amount, and the front wheel turning angle and additional yaw moment of the vehicle in the second control amount as the target control amount.

[0146] According to one embodiment of the present disclosure, each type of state quantity includes the longitudinal velocity, lateral velocity and yaw rate of the vehicle.

[0147] According to one embodiment of the present disclosure, a second state quantity of the vehicle is input into a stability controller, and the stability controller outputs a first front wheel steering angle and an additional yaw moment of the vehicle, including: adding an equivalent control force of the vehicle to a disturbance quantity of the stability controller; inputting the second state quantity of the vehicle and the disturbance quantity of the stability controller into the stability controller, and the stability controller outputs a first front wheel steering angle and an additional yaw moment.

[0148] According to one embodiment of the present disclosure, based on the three-degree-of-freedom dynamic model of the vehicle's longitudinal, lateral and yaw, a trajectory tracking controller and a stability controller of the vehicle are respectively constructed, including: constructing a trajectory tracking kinematic error model of the vehicle; constructing a trajectory tracking controller based on the three-degree-of-freedom dynamic model and the trajectory tracking kinematic error model.

[0149] Therefore, the vehicle's lateral and longitudinal coupling characteristics can be overcome through the disclosed solution. The stability controller and the trajectory tracking controller are generated through a three-degree-of-freedom dynamic model. Compared with the two-degree-of-freedom vehicle model, the three-degree-of-freedom model can better characterize the influence of the longitudinal vehicle speed on the yaw angular velocity and lateral velocity during emergency braking and steering conditions due to the addition of the longitudinal vehicle speed. At the same time, during the emergency braking and steering process, the motion characteristics of the entire vehicle when trajectory tracking and stability control work together on the vehicle chassis, through the designed coordinated control strategy, the outputs of the two controllers are appropriately adjusted, which can improve the accuracy of trajectory tracking while ensuring the stability of the vehicle.

[0150] In order to implement the above embodiment, the present disclosure further provides an electronic device 600, Figure 6 is a schematic diagram of an electronic device according to an embodiment of the present disclosure, such as Figure 6 As shown, the electronic device 600 includes: a processor 601 and a memory 602 that is communicatively connected to the processor, the memory 602 stores instructions that can be executed by at least one processor, and the instructions are executed by at least one processor 601 to implement the present disclosure. Figure 1-Figure 4 A vehicle control method according to an embodiment.

[0151] In order to implement the above embodiments, the present disclosure also provides a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to enable the computer to implement the above embodiments. Figure 1-Figure 4 A vehicle control method according to an embodiment.

[0152] In order to implement the above embodiments, the present disclosure also provides a computer program product, including a computer program. When the computer program is executed by a processor, the computer program implements the above embodiments. Figure 1-Figure 4 A vehicle control method according to an embodiment.

[0153] It should be noted that personal information from users should be collected for legitimate and reasonable purposes and should not be shared or sold outside of these legitimate uses. In addition, such collection / sharing should be carried out after receiving the user's informed consent, including but not limited to notifying the user to read the user agreement / user notice and sign the agreement / authorization including authorization of relevant user information before the user uses the function. In addition, any necessary steps should be taken to protect and safeguard access to such personal information data and ensure that others who have access to personal information data comply with its privacy policy and procedures.

[0154] The present application is expected to provide an implementation scheme for users to selectively block the use or access of personal information data. That is, the present disclosure is expected to provide hardware and / or software to prevent or block access to such personal information data. Once the personal information data is no longer needed, the risk can be minimized by limiting data collection and deleting the data. In addition, when applicable, such personal information is de-identified to protect the privacy of the user.

[0155] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0156] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0157] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0158] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that contains, stores, communicates, propagates or transmits a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (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 disk read-only memory (CDROM). In addition, the computer-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 in other suitable ways if necessary, and then stored in a computer memory.

[0159] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0160] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0161] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0162] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A vehicle control method, characterized in that: include: Based on the three-degree-of-freedom dynamic model of the vehicle, namely longitudinal, lateral and yaw, a trajectory tracking controller and a stability controller of the vehicle are respectively constructed; identifying whether the vehicle is in an unstable state; In response to the vehicle not being in an unstable state, disabling a vehicle control function of the stability controller and controlling the vehicle via the trajectory tracking controller; In response to the vehicle being in an unstable state, a vehicle control function of the stability controller is activated, and the vehicle is controlled by the trajectory tracking controller and the stability controller.

2. The method according to claim 1, characterized in that: After the vehicle is controlled by the trajectory tracking controller and the stability controller, the method further includes: In response to a sideslip angle of the vehicle being less than a first set value and a sideslip angle velocity of the vehicle being less than a second set value, a vehicle control function of the stability controller is disabled and the vehicle is controlled by the trajectory tracking controller.

3. The method according to claim 2, characterized in that After the vehicle is controlled by the trajectory tracking controller and the stability controller, the method further includes: In response to the center-of-mass sideslip angle being greater than or equal to a first set value, and / or the center-of-mass sideslip angle velocity being greater than or equal to a second set value, re-identifying whether the vehicle is in an unstable state; In response to the vehicle not being in an unstable state, a vehicle control function of the stability controller is disabled and the vehicle is controlled by the trajectory tracking controller.

4. The method according to claim 3, characterized in that After re-identifying whether the vehicle is in an unstable state, the method further includes: In response to the vehicle being in an unstable state, maintaining the vehicle control function of the stability controller in an activated state, and continuing to control the vehicle through the trajectory tracking controller and the stability controller.

5. The method according to claim 1, characterized in that The controlling of the vehicle by the trajectory tracking controller and the stability controller comprises: Inputting a first state quantity of the vehicle into the trajectory tracking controller, and having the trajectory tracking controller output a first control quantity of the vehicle; inputting a second state variable of the vehicle into the stability controller, and having the stability controller output a second control variable of the vehicle; The vehicle is controlled based on the first control amount and the second control amount.

6. The method according to claim 5, characterized in that The controlling the vehicle based on the first control amount and the second control amount includes: determining a target control amount of the vehicle from the first control amount and the second control amount to control the vehicle; and / or, The first control amount and the second control amount are fused to obtain the target control amount to control the vehicle.

7. The method according to claim 6, characterized in that The determining the target control amount of the vehicle from the first control amount and the second control amount includes: The equivalent longitudinal force of the vehicle in the first control amount, and the front wheel steering angle and additional yaw moment of the vehicle in the second control amount are used as the target control amount.

8. The method according to claim 5, characterized in that Each type of state quantity includes the longitudinal velocity, lateral velocity and yaw angular velocity of the vehicle.

9. The method according to claim 5, characterized in that The step of inputting the second state quantity of the vehicle into the stability controller, and outputting the first front wheel steering angle and the additional yaw moment of the vehicle by the stability controller, comprises: adding an equivalent control force of the vehicle to a disturbance amount of the stability controller; The second state quantity of the vehicle and the disturbance quantity of the stability controller are input to the stability controller, and the stability controller outputs the first front wheel turning angle and the additional yaw moment.

10. The method according to any one of claims 1 to 9, characterized in that The three-degree-of-freedom dynamic model based on the longitudinal, lateral and yaw of the vehicle respectively constructs a trajectory tracking controller and a stability controller of the vehicle, including: Constructing a trajectory tracking kinematic error model of the vehicle; The trajectory tracking controller is constructed based on the three-degree-of-freedom dynamics model and the trajectory tracking kinematic error model.

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