Steering Control Apparatus for Smooth Manual to Automatic Transition
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Solution Overview
Problem
Existing steering control systems for autonomous vehicles face challenges in smoothly transitioning from manual to automatic steering control, leading to vehicle and steering behavior disorders due to sudden corrections, especially when disturbances like crosswinds occur, and may result in vehicle deviation from the target route.
Innovation Solution
A steering control apparatus that calculates a command steering angle to gradually align the vehicle's route with the target route after switching to automatic control, using a recalculation method such as filtering or rate limiting to adjust the steering angle, and adjusts the control gain to maintain stability and trackability, preventing sudden steering corrections and suppressing disturbances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the control gain of the tracking control is lowered to suppress sudden steering corrections when switching from manual to automatic steering control, then the disorder of vehicle behavior and steering behavior is suppressed, but the correction amount of manipulated variable with respect to disturbance decreases and robustness to disturbance decreases
Solution Approach 1:
The control gain is made dynamic by switching between a first control gain (lower) when the vehicle is on the target traveling route and a second control gain (higher) when the vehicle deviates from the target route. This dynamic adjustment allows the system to maintain stability during normal operation while gaining robustness against disturbances when needed.
Solution Approach 2:
The control gain parameter is changed based on the vehicle's position relative to the target traveling route. When the vehicle deviates from the target route, the control gain is increased to enhance disturbance robustness and correction capability, while maintaining lower gain for stability when on route.
2Stability of the object's composition
If the control gain of the tracking control is lowered to gradually converge the vehicle traveling route to the target traveling route, then the disorder of vehicle behavior and steering behavior is suppressed, but the correction amount of manipulated variable with respect to disturbance decreases
Solution Approach 1:
The control gain is dynamically adjusted based on the vehicle's deviation from the target route. A lower gain is used when on route for smooth convergence, while a higher gain is activated when disturbed or off route to counteract harmful factors effectively.
Solution Approach 2:
The system continuously monitors the vehicle's position relative to the target traveling route and adjusts the control gain accordingly. When the vehicle deviates or experiences disturbance, feedback triggers an increase in control gain to counteract the harmful effects.
3Speed
If sudden steering is performed to return the vehicle to the target traveling route when switching from manual to automatic steering control, then the vehicle is quickly returned to the target route, but disorder of vehicle behavior and steering behavior is produced
Solution Approach 1:
The control gain is dynamically switched based on the vehicle's position. When the vehicle is on the target route, a lower gain provides smooth, stable convergence. When the vehicle deviates, a higher gain enables faster correction without causing excessive oscillation or disorder.
Solution Approach 2:
The control parameter (gain) is changed based on the deviation magnitude. This allows the system to adapt the correction speed to the situation, providing fast correction when needed while maintaining stability during normal operation.
Data Source
AI summary
The steering control apparatus determines whether or not a deviation degree of a current traveling route of a vehicle with respect to a target traveling route is equal to or more than a predetermined threshold, when steering control is switched from manual steering control to automatic steering control. In the automatic steering control, a command steering angle is calculated so that a difference between a real traveling route of the vehicle and the target traveling route is eliminated. However, when the deviation degree is equal to or more than the predetermined threshold, the steering control apparatus recalculates the command steering angle used in the command steering angle tracking control based on a steering angle at the time of starting the automatic steering control and the command steering angle so that a real steering angle after switching to the automatic steering control changes gradually to the command steering angle.