Vehicle Path Tracking Control With Dynamic Preview Steering
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Solution Overview
Problem
The accuracy of path tracking in automatic driving systems, particularly for off-road vehicles like agricultural vehicles, is low, leading to reduced operation quality and land utilization.
Innovation Solution
A method for controlling a vehicle that involves obtaining current state information, determining a preview tracking point based on reference information including preview time, calculating first and second turning angles to correct distance and heading errors, and performing a weighting calculation to determine a target turning angle for the front wheel. Parameters such as preview time and weights are dynamically adjusted based on the distance error between the vehicle and the target path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed path tracking control method is used, then the control system is simple, but the path tracking accuracy is low
Solution Approach 1:
The patent applies dynamics by making the preview time parameter dynamic rather than fixed. The preview time is adjusted in real-time based on the vehicle's distance to the target path, creating a dynamic control system that adapts to varying tracking conditions. This resolves the contradiction by implementing a moderately complex dynamic mechanism that significantly improves path tracking accuracy without requiring overly complex system architecture.
Solution Approach 2:
The patent changes the parameter of preview time from a constant value to a variable parameter that changes based on distance error. By establishing a correlation between preview time and distance to target path, the system dynamically adjusts control parameters to maintain optimal tracking accuracy across different operating conditions, thereby improving path tracking precision without excessive system complexity.
2Measurement precision
If the preview time is extended to improve tracking accuracy, then the path tracking accuracy improves, but the response time increases
Solution Approach 1:
The patent resolves this time-accuracy tradeoff by making preview time dynamic. When the vehicle is far from the target path, a longer preview time provides earlier guidance for corrective action. When the vehicle is close to the path, the preview time automatically shortens to reduce lag and improve responsiveness. This dynamic adjustment optimizes both tracking accuracy and response time across different operational states.
Solution Approach 2:
The patent changes preview time from a fixed parameter to a distance-dependent variable parameter. By establishing a functional relationship where preview time correlates with distance to target path, the system automatically optimizes the balance between lookahead distance (for accuracy) and response lag (for speed), resolving the contradiction between these two performance metrics.
3Measurement precision
If the vehicle follows the target path closely, then the path tracking accuracy improves, but the operation stability decreases
Solution Approach 1:
The patent applies dynamics by making the weighting factor dynamic rather than fixed. The weighting factor adjusts based on the vehicle's distance to the target path, balancing the competing requirements of path following accuracy and operational stability. This dynamic weighting resolves the contradiction by adapting the control strategy to current tracking conditions without requiring overly complex multi-mode control systems.
Solution Approach 2:
The patent changes the weighting factor from a constant to a distance-dependent variable parameter. By establishing a correlation between the weighting factor and distance to target path, the system dynamically balances the contribution of different control objectives (path accuracy versus stability), thereby resolving the contradiction between these two performance requirements.
Data Source
AI summary
Provided are a method and device for controlling a vehicle and a vehicle, and relates to the technical field of automatic driving. The method for controlling a vehicle includes: obtaining current state information of the vehicle, wherein the state information includes a position information and an attitude information; determining a preview tracking point from a plurality of path points of a target path to be tracked by the vehicle based on a reference information, wherein the reference information includes a preview time; determining a first turning angle and a second turning angle of a front wheel of the vehicle based on the position information and the attitude information, wherein the first turning angle is used for eliminating a distance error between the vehicle and the preview tracking point, and the second turning angle is used for eliminating a heading error between the vehicle and the preview tracking point; and performing a weighting calculation on the first turning angle and the second turning angle to determine a target turning angle for controlling the front wheel, wherein a minimum distance among a plurality of distances between the vehicle and the plurality of path points is a first distance, and at least one parameter of the preview time or a weight corresponding to the first turning angle is positively correlated with the first distance in a case where the first distance is within a preset distance range.