Automatic driving path tracking and vehicle stability control cooperation method and system

Abstract

The invention discloses an automatic driving path tracking and vehicle stability control cooperation method and system, and the method comprises the steps: determining whether a vehicle is in an automatic driving mode or a manual driving mode based on a driving mode judgment module; when the vehicle is in a manual driving mode, the vehicle stability control module and the chassis fusion control module identify and control the driving action of the vehicle according to the intention of a driver; when the vehicle is in an automatic driving mode, the driving action of the vehicle is jointly controlled by an automatic driving module, a limit working condition extension control safety judgment module, a vehicle stability control module, a chassis fusion control module and the like; the stability control triggering frequency is reduced and the safety problem caused by the exit of the automatic driving system is alleviated and even avoided on the premise of ensuring the safety and in the scene that the stability control of the vehicle is easily triggered originally, such as lane change on a low-adhesion road surface.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile automatic driving and intelligent chassis, and in particular to a method and system for coordinating automatic driving path tracking and vehicle stability control. Background Art

[0002] In recent years, the technology of autonomous driving has become more and more mature, and the level of autonomous driving on mass-produced models is gradually approaching L3, and more and more working conditions can be covered by the autonomous driving system. With the widespread application of autonomous driving technology, the problem of autonomous driving exiting and taking over has gradually emerged, and has received attention from the automotive academic and industrial circles. Among them, the representative problem is that the lane change of autonomous driving vehicles on slippery roads may trigger vehicle stability control, causing the autonomous driving system to exit and take over, creating safety hazards. Under this special working condition, how to reduce or avoid the triggering of stability control while completing the lane change operation of autonomous driving under the premise of safety is an issue that needs to be solved urgently. Summary of the invention

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

[0004] The present invention proposes a method for coordinating automatic driving path tracking and vehicle stability control, which can reduce or even avoid the phenomenon of automatic driving exit when automatically changing lanes on slippery and low-adhesion roads, thereby ensuring the safety performance of the vehicle.

[0005] Another object of the present invention is to propose an autonomous driving path tracking and vehicle stability control collaborative system.

[0006] To achieve the above objectives, the present invention provides, on one hand, a method for coordinating automatic driving path tracking and vehicle stability control, comprising:

[0007] S100 identifies vehicle driving mode;

[0008] S101 determines whether to enter the automatic driving mode; if it is identified as the manual driving mode, enter S109, if it is identified as the automatic driving mode, enter S102;

[0009] S109 performs driver intention analysis;

[0010] S110 performs calculation of key states for determining vehicle stability;

[0011] S111 determines whether the key state exceeds the first stability triggering threshold in the current state; if it exceeds the first stability triggering threshold, enter S112; if it does not exceed the first stability triggering threshold, enter S113;

[0012] S112 activates the vehicle stability control algorithm and controls the chassis actuators;

[0013] S113 activates chassis fusion control to optimize the distribution of actuators, and finally controls the chassis actuators for control;

[0014] S102 receiving a current state stability triggering a second threshold;

[0015] S103 plans an automatic driving path using the second threshold as a hard constraint, and calculates a key state for current stability determination;

[0016] S104 compares the stability to determine whether the key state exceeds the stability triggering first threshold, if not, proceed to S108; if yes, proceed to S105;

[0017] S105 determines whether the stability exceeds the second threshold. If it exceeds the second threshold, the process proceeds to S106. If it does not exceed the second threshold, the process proceeds to S107.

[0018] S106 activates the vehicle stability control algorithm and controls the chassis actuators;

[0019] S107 determines whether the path tracking error and the vehicle stability trend are safe. If they are within the safe range, the process proceeds to S108; if they are not within the safe range, the process proceeds to S106;

[0020] S108 performs chassis fusion control with the second stability threshold as a soft constraint, and ultimately controls the chassis actuator.

[0021] The autonomous driving path tracking and vehicle stability control collaboration method of the embodiment of the present invention may also have the following additional technical features:

[0022] In one embodiment of the present invention, when the vehicle is in manual driving mode, it is determined whether to activate the vehicle stability control algorithm according to the vehicle stability determination key state and the stability triggering first threshold value. If the stability determination key state exceeds the stability triggering first threshold value, the vehicle stability control algorithm is activated to control the movement of the vehicle according to the driver's intention and the ideal steering characteristic; if the stability determination key state does not exceed the stability triggering first threshold value, a chassis actuator control command is allocated according to the driver's intention, and the movement of the vehicle is controlled;

[0023] When the vehicle is in the automatic driving mode, it receives the stability triggering second threshold, takes the stability triggering second threshold as a hard constraint, and dynamically adjusts the planned path.

[0024] In one embodiment of the present invention, based on the vehicle state information, when the key state for determining vehicle stability is less than the first threshold value for triggering stability of the current vehicle state, the vehicle stability control program is not activated; when the key state for determining stability, such as the vehicle yaw angular velocity, exceeds the original stability trigger threshold value under the current vehicle state and is less than the second threshold value for triggering stability under the current vehicle state, it is determined whether the path tracking error and the vehicle stability trend at the current moment are within a safe range, if so, the vehicle stability control program is not activated, if not, the vehicle stability control program is activated; when the key state for determining stability, such as the vehicle yaw angular velocity, exceeds the second threshold value for triggering stability under the current vehicle state, the vehicle stability control program is activated.

[0025] In one embodiment of the present invention, whether the path tracking error and vehicle stability trend at the current moment are within a safe range includes:

[0026] If the deviation between the current vehicle's actual path and the autonomous driving planned path is less than the trajectory tolerance threshold, and the time exceeding the stability trigger threshold is less than the trajectory tolerance threshold, then it is within the safe range, otherwise it is in the unsafe range.

[0027] In one embodiment of the present invention, the key state for determining vehicle stability includes: one or more combinations of yaw rate, sideslip angle of center of mass, vehicle speed, wheel speed, and road adhesion information.

[0028] In one embodiment of the present invention, the chassis fusion control system receives a stability trigger first threshold and sets it as a soft constraint; when the stability control program is not activated, the driving path planned by the autonomous driving is received, and motion control and execution control optimization allocation are performed in combination with the soft constraint to control the movement of the vehicle; when the stability control program is activated, the driving path is locally adjusted based on the received driving path planned by the autonomous driving to assist in maintaining the stability of the vehicle posture until the stability control algorithm exits.

[0029] To achieve the above-mentioned object, the present invention further provides an autonomous driving path tracking and vehicle stability control cooperation system, comprising:

[0030] A driving mode determination module, used to determine whether the vehicle is in a manual driving mode or an automatic driving mode;

[0031] The autonomous driving module is used to plan the autonomous driving path;

[0032] The extreme working condition extended control safety judgment module is used to monitor whether the vehicle is in a controllable motion range in the autonomous driving mode and activate the vehicle stability control before serious instability occurs;

[0033] A vehicle stability control module, used to call the vehicle stability control algorithm in manual driving mode and automatic driving mode;

[0034] The chassis fusion control module is used to distribute chassis actuator control commands and control the vehicle's movement in manual driving mode. In automatic driving mode, it constrains motion control and optimizes distributed execution control when stability control is not activated. When stability control is activated, it assists stability control to maintain the stability of the vehicle's posture.

[0035] The autonomous driving path tracking and vehicle stability control collaboration method and system of the embodiments of the present invention redefine the relationship between the two tasks of path tracking and vehicle stability control in the autonomous driving mode, fully expand the available motion range in the autonomous driving mode, improve the scope of application of autonomous driving, and reduce the safety risks caused by the exit of autonomous driving.

[0036] Additional aspects and advantages of the present invention 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 invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0038] Figure 1 is a flow chart of a method for coordinating an autonomous driving path tracking and vehicle stability control according to an embodiment of the present invention;

[0039] Figure 2 is a structural diagram of an autonomous driving path tracking and vehicle stability control collaborative system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0042] The following describes the autonomous driving path tracking and vehicle stability control collaboration method and system proposed according to an embodiment of the present invention with reference to the accompanying drawings.

[0043] Figure 1is a flow chart of a method for coordinating an automatic driving path tracking and a vehicle stability control according to an embodiment of the present invention. Figure 1 As shown, the method includes:

[0044] S100 identifies vehicle driving mode;

[0045] S101 determines whether to enter the automatic driving mode; if it is identified as the manual driving mode, enter S109, if it is identified as the automatic driving mode, enter S102;

[0046] S109 performs driver intention analysis;

[0047] S110 performs calculation of key states for determining vehicle stability;

[0048] S111 determines whether the key state exceeds the first stability triggering threshold in the current state; if it exceeds the first stability triggering threshold, enter S112; if it does not exceed the first stability triggering threshold, enter S113;

[0049] S112 activates the vehicle stability control algorithm and controls the chassis actuators;

[0050] S113 activates chassis fusion control to optimize the distribution of actuators, and finally controls the chassis actuators for control;

[0051] S102 receiving a current state stability triggering a second threshold;

[0052] S103 plans an automatic driving path using the second threshold as a hard constraint, and calculates a key state for current stability determination;

[0053] S104 compares the stability to determine whether the key state exceeds the stability triggering first threshold, if not, proceed to S108; if yes, proceed to S105;

[0054] S105 determines whether the stability exceeds the second threshold. If it exceeds the second threshold, the process proceeds to S106. If it does not exceed the second threshold, the process proceeds to S107.

[0055] S106 activates the vehicle stability control algorithm and controls the chassis actuators;

[0056] S107 determines whether the path tracking error and the vehicle stability trend are safe. If they are within the safe range, the process proceeds to S108; if they are not within the safe range, the process proceeds to S106;

[0057] S108 performs chassis fusion control with the second stability threshold as a soft constraint, and ultimately controls the chassis actuator.

[0058] In one embodiment of the present invention, the autonomous driving path tracking and vehicle stability control collaboration method of the present invention can determine whether the vehicle is in autonomous driving mode or manual driving mode based on the driving mode judgment module; when the vehicle is in manual driving mode, the vehicle stability control module and the chassis fusion control module control the vehicle's driving action based on the driver's intention recognition; when the vehicle is in autonomous driving mode, the autonomous driving module, the extreme working condition extended control safety judgment module, the vehicle stability control module, the chassis fusion control module, etc. jointly control the vehicle's driving action.

[0059] In one embodiment of the present invention, when the vehicle is in manual driving mode, the vehicle stability control module includes: judging whether to activate the vehicle stability control algorithm according to the vehicle stability judgment key state and the stability trigger first threshold; if the stability judgment key state exceeds the stability trigger first threshold, activating the vehicle stability control algorithm to control the movement of the vehicle according to the driver's intention and ideal steering characteristics; if the stability judgment key state does not exceed the stability trigger first threshold, the chassis fusion control module allocates chassis actuator control commands and controls the movement of the vehicle according to the driver's intention, taking into account the vehicle's movement safety, economy, comfort and other goals.

[0060] In one embodiment of the present invention, the key state for determining stability includes one or more combinations of information such as yaw rate, sideslip angle of center of mass, vehicle speed, wheel speed, and road adhesion, which can be obtained through theoretical deduction or experimental calibration.

[0061] In one embodiment of the present invention, when the vehicle is in the automatic driving mode, the automatic driving module includes: the automatic driving module receives the stability triggering second threshold value sent by the stability control module, takes the stability triggering second threshold value as a hard constraint (which cannot be violated or exceeded), dynamically adjusts the planned path in combination with the traffic environment, and sends the planned path to the chassis fusion control module.

[0062] In one embodiment of the present invention, the extreme working condition extended control safety judgment module of the automatic driving mode includes: combining the vehicle state information such as the current vehicle speed and wheel speed, when the key state for determining stability such as the vehicle yaw angular velocity is less than the first threshold for triggering stability of the current vehicle state, the vehicle stability control module is not activated; when the key state for determining stability such as the vehicle yaw angular velocity exceeds the original stability trigger threshold under the current vehicle state and is less than the second threshold for triggering stability under the current vehicle state, it is determined whether the path tracking error and the vehicle stability trend at the current moment are within a safe range, if so, the vehicle stability control module is not activated, otherwise the vehicle stability control module is activated; when the key state for determining stability such as the vehicle yaw angular velocity exceeds the second threshold for triggering stability under the current vehicle state, the vehicle stability control module is activated.

[0063] In one embodiment of the present invention, the key state for determining stability includes one or more combinations of information such as yaw rate, sideslip angle of center of mass, vehicle speed, wheel speed, and road adhesion, which can be obtained through theoretical deduction or experimental calibration.

[0064] In one embodiment of the present invention, whether the current path tracking error and vehicle stability trend of the extreme operating condition extended control safety judgment module are within a safe range includes: if the deviation between the current actual path of the vehicle and the automatic driving planned path is less than the trajectory allowable deviation threshold, and the time exceeding the stability trigger threshold is less than the trajectory allowable deviation threshold, then it is within the safe range, otherwise it is within the unsafe range; the trajectory allowable deviation threshold and the trajectory allowable deviation threshold can be obtained by theoretical derivation or experimental calibration.

[0065] In one embodiment of the present invention, the vehicle stability control module of the automatic driving mode includes: the vehicle stability control module sends a stability trigger second threshold to the automatic driving module, and sends a stability trigger first threshold to the chassis fusion control module; when the stability control module is activated, the vehicle stability control algorithm is called, and the actuator command is sent directly to the chassis actuator.

[0066] In one embodiment of the present invention, the chassis fusion control module of the automatic driving mode includes: the chassis fusion control module receives the first threshold value of the stability trigger and sets it as a soft constraint (allowing short-term violation or exceeding); when the stability control module is not activated, it receives the driving path planned by the automatic driving, and performs motion control and execution control optimization allocation in combination with the soft constraint to control the movement of the vehicle; when the stability control module is activated, based on the received driving path planned by the automatic driving, it locally adjusts the driving path to assist the stability control module in maintaining the stability of the vehicle posture until the stability control algorithm exits.

[0067] With the improvement and application of autonomous driving levels, the problems solved by this method and system will gradually become apparent, providing solutions for subsequent industrial applications, greatly improving the driving safety performance of autonomous driving vehicles, and having strong prospects for implementation and application.

[0068] The method for coordinating the path tracking and vehicle stability control of the automatic driving according to the embodiment of the present invention takes into account the coordination of path planning and vehicle stability control in the automatic driving mode. On the one hand, it limits the automatic driving path planning to a path that causes serious vehicle instability. On the other hand, compared with the traditional conservative stability control, it expands the motion control range available for path planning, and stabilizes it to be triggered only in extremely serious instability. The combination of the two improves the control capability of the automatic driving motion control under extreme working conditions, reduces or even reduces the exit of the automatic driving due to the triggering of stability control, and improves the vehicle's motion safety performance.

[0069] In order to implement the above embodiment, this embodiment also provides an autonomous driving path tracking and vehicle stability control collaboration system, including:

[0070] A driving mode determination module, used to determine whether the vehicle is in a manual driving mode or an automatic driving mode;

[0071] The autonomous driving module is used to plan the autonomous driving path;

[0072] The extreme working condition extended control safety judgment module is used to monitor whether the vehicle is in a controllable motion range in the autonomous driving mode and activate the vehicle stability control before serious instability occurs;

[0073] A vehicle stability control module, used to call the vehicle stability control algorithm in manual driving mode and automatic driving mode;

[0074] The chassis fusion control module is used to distribute chassis actuator control commands and control the vehicle's movement in manual driving mode. In automatic driving mode, it constrains motion control and optimizes distributed execution control when stability control is not activated. When stability control is activated, it assists stability control to maintain the stability of the vehicle's posture.

[0075] Specifically, Figure 2 It is a schematic diagram of the automatic driving path tracking and vehicle stability control cooperation system of the present invention. Under the judgment of the driving mode judgment module 201, in the manual driving mode, the driver 301 receives the environmental information 300 and manipulates the control mechanism 302, and the vehicle stability control module 204 and the chassis fusion control module 205 recognize the driver's intention and control the actuator 303 to realize the motion control of the vehicle 304; in the automatic driving mode, the automatic driving module 202 receives the environmental information 300, cooperates with the vehicle stability control module 204 to plan a safe path, the extreme working condition extended control safety judgment module 204 and the chassis fusion control module 205 cooperate to expand the chassis controllable motion range, control the actuator 303 and implement the vehicle 304 motion control, the extreme working condition extended control safety judgment module 204 and the vehicle stability control module 205 cooperate to implement the stability algorithm under the unavoidable severe instability condition, and control the actuator 303 to realize the motion control of the vehicle 304.

[0076] The autonomous driving path tracking and vehicle stability control collaboration system according to the embodiment of the present invention takes into account the coordination of path planning and vehicle stability control in the autonomous driving mode. On the one hand, it limits the autonomous driving path planning to paths that cause serious vehicle instability. On the other hand, compared with the traditional conservative stability control, it expands the motion control range available for path planning, and stabilizes it to be triggered only in extremely serious instability. The combination of the two improves the control capability of autonomous driving motion control under extreme working conditions, reduces or even reduces the exit of autonomous driving caused by the triggering of stability control, and improves the vehicle's motion safety performance.

[0077] In the description of this specification, 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 invention. 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.

[0078] 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 the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Claims

1. A method for coordinating automatic driving path tracking and vehicle stability control, characterized in that: include: S100 identifies vehicle driving mode; S101 determines whether to enter the automatic driving mode; if it is identified as the manual driving mode, enter S109, if it is identified as the automatic driving mode, enter S102; S109 performs driver intention analysis; S110 performs calculation of key states for determining vehicle stability; S111 determines whether the critical state exceeds the stability triggering first threshold in the current state; If the stability triggering first threshold is exceeded, the process proceeds to S112; If the stability triggering first threshold is not exceeded, the process goes to S113; S112 activates the vehicle stability control algorithm and controls the chassis actuators; S113 activates chassis fusion control to optimize the distribution of actuators, and finally controls the chassis actuators for control; S102 receiving a current state stability triggering a second threshold; S103 plans an automatic driving path using the second threshold as a hard constraint, and calculates a key state for current stability determination; S104 compares the stability to determine whether the key state exceeds the stability triggering first threshold, if not, proceed to S108; if yes, proceed to S105; S105 determines whether the stability exceeds the second threshold. If it exceeds the second threshold, the process proceeds to S106. If it does not exceed the second threshold, the process proceeds to S107. S106 activates the vehicle stability control algorithm and controls the chassis actuators; S107 determines whether the path tracking error and the vehicle stability trend are safe. If they are within the safe range, the process proceeds to S108; if they are not within the safe range, the process proceeds to S106; S108 performs chassis fusion control with the second stability threshold as a soft constraint, and ultimately controls the chassis actuator.

2. The method according to claim 1, characterized in that When the vehicle is in the manual driving mode, judging whether to activate the vehicle stability control algorithm according to the key state of vehicle stability judgment and the first stability triggering threshold, activating the vehicle stability control algorithm if the key state of stability judgment exceeds the first stability triggering threshold, and controlling the movement of the vehicle according to the driver's intention and the ideal steering characteristic; if the key state of stability judgment does not exceed the first stability triggering threshold, assigning a chassis actuator control command according to the driver's intention, and controlling the movement of the vehicle; When the vehicle is in the automatic driving mode, it receives the stability triggering second threshold, takes the stability triggering second threshold as a hard constraint, and dynamically adjusts the planned path.

3. The method according to claim 1, characterized in that According to the vehicle state information, when the vehicle stability determination key state is less than the current vehicle state stability triggering first threshold value, the vehicle stability control program is not activated; When the key stability determination state such as the vehicle yaw rate exceeds the original stability trigger threshold under the current vehicle state and is less than the second stability trigger threshold under the current vehicle state, determine whether the path tracking error and the vehicle stability trend at the current moment are within the safety range. If so, do not activate the vehicle stability control program; if not, activate the vehicle stability control program; When the key stability determination state such as the vehicle yaw rate exceeds the stability triggering second threshold under the current vehicle state, the vehicle stability control program is activated.

4. The method according to claim 3, characterized in that Whether the path tracking error and vehicle stability trend at the current moment are within a safe range includes: If the deviation between the current vehicle's actual path and the autonomous driving planned path is less than the trajectory tolerance threshold, and the time exceeding the stability trigger threshold is less than the trajectory tolerance threshold, then it is within the safe range, otherwise it is in the unsafe range.

5. The method according to claim 1, characterized in that The key state for determining vehicle stability includes: one or more combinations of yaw rate, center of mass sideslip angle, vehicle speed, wheel speed, and road adhesion information.

6. The method according to claim 1, characterized in that The chassis fusion control system receives the first stability trigger threshold and sets it as a soft constraint. When the stability control program is not activated, it receives the driving path planned by the autonomous driving, and performs motion control and execution control optimization allocation in combination with the soft constraints to control the movement of the vehicle. When the stability control program is activated, based on the received driving path planned by the autonomous driving, it locally adjusts the driving path to help maintain the stability of the vehicle's posture until the stability control algorithm exits.

7. An autonomous driving path tracking and vehicle stability control collaborative system, characterized in that: include: A driving mode determination module, used to determine whether the vehicle is in a manual driving mode or an automatic driving mode; The autonomous driving module is used to plan the autonomous driving path; The extreme working condition extended control safety judgment module is used to monitor whether the vehicle is in a controllable motion range in the autonomous driving mode and activate the vehicle stability control before serious instability occurs; A vehicle stability control module, used to call the vehicle stability control algorithm in manual driving mode and automatic driving mode; The chassis fusion control module is used to distribute chassis actuator control commands and control the vehicle's movement in manual driving mode. In automatic driving mode, it constrains motion control and optimizes distributed execution control when stability control is not activated. When stability control is activated, it assists stability control to maintain the stability of the vehicle's posture.

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