A method for preventing steering wheel shaking after intelligent driving parking is ended

Abstract

A method for preventing steering wheel shaking after intelligent driving parking is ended, comprising the following steps: in step S101, vehicle state information and vehicle environment information are collected to obtain predicted trajectory information; the vehicle state information comprises vehicle motion state and vehicle self parameters, and the vehicle environment information comprises obstacle conditions around the vehicle; in step S102, according to physical constraint conditions, the vehicle state information, the vehicle environment information and the predicted trajectory information are combined to obtain moving route information and moving speed information; and in step S103, the vehicle executes the moving route information and the moving speed information. By applying the method, the internal stress of an electric power steering system (EPS) executor hardware can be eliminated, and the steering wheel shaking can be effectively prevented.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobiles, in particular to a method for preventing steering wheel shaking after intelligent driving parking is completed. BACKGROUND

[0002] Parking scenarios are always the starting point and end point of a driving path, and are a high-frequency scenario for driving a vehicle. The current parking lot is limited by the site and space, and these factors greatly test the parking skills of the driver and consume the time and energy of the driver. With the development of intelligent driving technology, many car companies have begun to configure auxiliary driving automatic parking functions, which can solve the problem of parking to a certain extent and meet the needs of users for convenient parking.

[0003] However, in the prior art, during the automatic driving process of the vehicle in the parking-out / parking-in working condition, due to the load on the steering shaft, some lateral stress may be maintained in the steering mechanical system after the vehicle completes the automatic parking and the control system is disconnected from the actuator. This stress will cause the steering wheel to shake and affect the driving experience. SUMMARY

[0004] In view of the defects in the prior art, the purpose of the present application is to provide a method for preventing steering wheel shaking after intelligent driving parking is completed, which eliminates the internal stress of the electric power steering system (EPS) actuator hardware by planning a straight line after parking is completed., effectively prevent the steering wheel from shaking.

[0005] To achieve the above technical effects, the present application adopts the following technical solutions:

[0006] The present application provides a method for preventing steering wheel shaking after intelligent driving parking is completed, comprising:

[0007] In step S101, vehicle state information and vehicle environment information are collected to obtain predicted trajectory information;

[0008] The vehicle state information includes vehicle motion state and vehicle self parameters, and the vehicle environment information includes the obstacle condition around the vehicle;

[0009] In step S102, according to the physical constraint condition, the vehicle state information, the vehicle environment information and the predicted trajectory information are combined to obtain the movement route information and the movement speed information;

[0010] In step S103, the vehicle executes the movement route information and the movement speed information.

[0011] Preferably, the physical constraint condition includes acceleration / deceleration constraint, nonholonomic constraint and dynamics constraint.

[0012] Preferably, the moving speed information comprises: the vehicle speed during the vehicle executing the moving route information process should be less than a preset speed threshold value.

[0013] The vehicle acceleration during the vehicle executing the moving route information process should be less than a preset acceleration threshold value.

[0014] Preferably, in the moving speed information, when the vehicle finishes executing the moving route information, the speed is 0 and the acceleration is 0.

[0015] Preferably, when the moving route information is planned, the following steps are included:

[0016] In step 201, a starting node is selected, the distance of the starting node is set to 0, and the distances of all other nodes are set to infinity.

[0017] In step 202, in combination with the physical constraint condition, the node closest to the starting node from the unprocessed nodes is selected as the selected node.

[0018] In step S203, for the selected node, the distance from the starting node to its neighbor node through the selected node is calculated, and if the distance from the neighbor node to the starting node through the selected node is less than the distance from the neighbor node to the starting node, the distance of the neighbor node is updated to the newly calculated distance.

[0019] In step S204, the selected node is marked as processed.

[0020] In step S205, steps S202 to S204 are repeated until all nodes are processed or the target node is processed.

[0021] In step S206, the shortest path is constructed by backtracking from the target node to the starting node.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The present application can plan a driving route according to current vehicle state information, vehicle environment information, predicted trajectory information, etc., in combination with physical constraint conditions, so as to eliminate the internal stress of the electric power steering system (EPS) executor hardware and effectively prevent the steering wheel from shaking. BRIEF DESCRIPTION OF DRAWINGS

[0024] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the accompanying drawings:

[0025] Figure 1 The method flowchart of the embodiments of the present application is shown in the figure;

[0026] Figure 2A route planning example of an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0029] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, all directional indications (such as up, down, left, right, front, back, bottom, etc.) in the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), if the specific posture changes, the directional indications also change accordingly. DETAILED DESCRIPTION

[0031] The technical solutions of the present application will be described in detail below through embodiments, the following embodiments are only exemplary, and can only be used to explain and illustrate the technical solutions of the present application, but not to be interpreted as a limitation on the technical solutions of the present application.

[0032] When the vehicle completes automatic parking, the control system (host computer) is disconnected with the actuator, and some lateral stress may be maintained in the steering mechanical system. This stress will cause the steering wheel to shake, affecting the driving experience. In order to solve this problem, the embodiment provides a method for preventing the steering wheel from shaking after intelligent driving parking ends. The vehicle system can plan and execute a small straight driving according to the current vehicle motion state, obstacle information, and vehicle itself parameters, etc. information, combined with the kinematics limit of the vehicle, to eliminate the residual stress in the electric power steering system (EPS) actuator, so as to reduce the shaking feeling of the steering wheel.

[0033] As shown in Figure 1 The method provided by the embodiment includes the following steps:

[0034] In step S101, current vehicle state information and vehicle environment information are collected, and predicted trajectory information is obtained, which is then transmitted to the vehicle path planning module. The vehicle state information includes vehicle motion status, obstacle information, and vehicle parameters. This information can be collected by the vehicle's own sensors, such as onboard cameras or radar, or by other means, which are not limited in this embodiment.

[0035] In step S102 , the vehicle path planning module performs route planning based on physical constraints, vehicle state information, vehicle environment information, and predicted trajectory information to obtain moving route information and moving speed information.

[0036] In step S103, the vehicle performs movement route information and movement speed information.

[0037] Preferably, the movement speed information should at least include the vehicle speed and acceleration when the vehicle actually executes the movement route information, so that the vehicle can smoothly complete the planned route. That is, when the vehicle executes the movement route information, the vehicle speed is always less than a preset speed threshold, and the vehicle acceleration is always less than a preset acceleration threshold. Preferably, when the vehicle completes the movement route information, its speed should be 0 and its acceleration should be 0, so that the vehicle can stop exactly at the end point of the planned route.

[0038] Furthermore, the specific steps in the route planning process are explained, including the following steps:

[0039] In step S201, initialization is performed by selecting a starting node, setting the distance of the starting node to 0, and setting the distances of all other nodes to infinity.

[0040] In step S202, the nearest node is selected. Based on the physical constraints, the node closest to the starting node is selected from the unprocessed nodes as the selected node. Initially, the nearest node is the starting node.

[0041] In step S203, the distance is updated. For the selected node, the distance from the starting node through it to its neighboring nodes is calculated. If the distance from the selected node to the neighboring node is less than the distance from the starting node to the neighboring node, the distance of the neighboring node is updated to the newly calculated distance.

[0042] In step S204, the processed node is marked. Marking the selected node as processed indicates that the shortest path from the starting node to the node has been found.

[0043] In step S205, steps S202 to S204 are repeated, and the process of selecting the nearest node, updating the distance, and marking the processed node is repeated until the target node is processed.

[0044] In step S206, path backtracking is performed. Once the target node is processed, the shortest path can be constructed by backtracking from the target node to the start node.

[0045] In actual scenarios, the planning process needs to consider various physical constraints, including acceleration / deceleration constraints, nonholonomic constraints, and dynamic constraints. Specifically, the acceleration / deceleration constraints consider the performance limits of the powertrain and braking system, as well as the safety and comfort constraints of the driver, ensuring that the acceleration and deceleration of the vehicle are within a safe range and avoiding discomfort and danger caused by rapid acceleration or deceleration.

[0046] The nonholonomic constraint refers to the fact that the vehicle has three degrees of freedom of motion, namely lateral, longitudinal, and rotational, but only two degrees of freedom of control, i.e., only forward / reverse and steering motion, which determines that the vehicle cannot move directly sideways and needs to change the lateral position through steering, i.e., this nonholonomic constraint determines the physical feasibility of the trajectory.

[0047] The dynamic constraint refers to considering the dynamic characteristics of the vehicle, such as the maximum steering angle, the minimum turning radius, and the body stability, to ensure that the vehicle remains stable during turning and acceleration / deceleration, thus having certain constraints on the curvature and yaw rate during vehicle driving.

[0048] The vehicle motion planning principle plans a straight line of a preset length according to the current vehicle motion state, obstacle information, and vehicle parameters, etc., to eliminate the internal stress of the EPS actuator hardware and effectively prevent steering wheel shaking. In this embodiment, the length of the straight line planned is 20 cm, as shown in FIG. 1, the vehicle travels from S1 to S2, the initial speed is V1, the initial acceleration is a1, when it travels to S2, the speed is 0, and the acceleration is 0, wherein S2-S1=20 cm. Figure 2

[0049] The above describes specific embodiments of the present application, and through the above description, relevant personnel can make various changes and modifications without deviating from the technical concept of the present application.​

Claims

1. A method for preventing steering wheel vibration after intelligent driving parking is completed, characterized in that: include: In step S101, vehicle status information and vehicle environment information are collected to obtain predicted trajectory information; The vehicle state information includes the vehicle motion state and the vehicle's own parameters, and the vehicle environment information includes the obstacle conditions around the vehicle; In step S102, according to the physical constraints, combined with the vehicle state information, vehicle environment information, and predicted trajectory information, the moving route information and moving speed information are planned and obtained; In step S103, the vehicle executes the moving route information and the moving speed information; The moving speed information includes: the vehicle speed during the process of executing the moving route information should be less than a preset speed threshold; The vehicle acceleration during the execution of the movement route information should be less than a preset acceleration threshold; Planning and obtaining movement route information includes the following steps: In step 201, a starting node is selected, the distance of the starting node is set to 0, and the distances of all other nodes are set to infinity; In step 202, in combination with the physical constraint condition, the node closest to the starting node is selected from the unprocessed nodes as the selected node; In step S203, for the selected node, the distance from the starting node through it to its neighboring node is calculated. If the distance from the selected node to the neighboring node is less than the distance from the starting node to the neighboring node, the distance of the neighboring node is updated to the newly calculated distance. In step S204, the selected node is marked as processed; In step S205, steps S202 to S204 are repeated until the target node is processed; In step S206, the shortest path is constructed by backtracking from the target node to the starting node.

2. The method for preventing steering wheel vibration after intelligent driving parking according to claim 1 is characterized in that: The physical constraints include acceleration and deceleration constraints, non-holonomic constraints, and dynamic constraints.

3. The method for preventing steering wheel vibration after intelligent driving parking according to claim 2 is characterized in that: In the moving speed information, when the vehicle completes executing the moving route information, its speed is 0 and its acceleration is 0.

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