Vehicle Steering Setpoint Control for Safe Driver Takeover
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Solution Overview
Problem
Automatic Emergency Steering (AES) systems in vehicles often impose a limited and uncontrollable trajectory, making it difficult for drivers to safely regain control, especially when avoiding obstacles.
Innovation Solution
A method for autonomously controlling a vehicle's movement by acquiring trajectory parameters and computing a new control setpoint using a controller that limits the speed of direction change, employing a hyperbolic tangent function to determine a saturated turning angle setpoint, allowing for safe driver intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If AES system imposes a limited trajectory on the vehicle to avoid obstacles, then collision avoidance capability is improved, but driver controllability deteriorates
Solution Approach 1:
The patent applies dynamics by making the control setpoint variable and adaptive rather than fixed. The controller dynamically adjusts the steering angle setpoint based on real-time vehicle state and trajectory requirements, allowing the system to transition between autonomous avoidance mode and driver-controlled mode smoothly, thus resolving the contradiction between automated safety and driver controllability
Solution Approach 2:
The patent implements feedback mechanisms where the controller continuously monitors vehicle trajectory, steering angle, and driver input to adjust the control setpoint. This closed-loop feedback allows the system to maintain collision avoidance effectiveness while detecting when driver intervention is needed, thereby preserving both safety and driver controllability
2Loss of time
If the vehicle follows a desired trajectory quickly to avoid obstacles, then response time is improved, but trajectory following stability deteriorates
Solution Approach 1:
The controller dynamically adapts the trajectory following parameters based on vehicle speed, steering capabilities, and trajectory complexity. By making the control parameters variable rather than fixed, the system achieves fast response when conditions permit while maintaining stability when conditions require more conservative control, resolving the contradiction between speed and stability
Solution Approach 2:
The patent changes control parameters such as steering angle limits, acceleration rates, and trajectory deviation thresholds based on real-time vehicle state. This parameter adaptation allows the vehicle to respond quickly to obstacles when safe while maintaining trajectory following stability under normal conditions, effectively resolving the response time versus stability contradiction
Data Source
AI summary
A method autonomously controls a mobility of an automotive apparatus, which mobility is such as to have an influence on the path of the apparatus. The method includes steps of: acquiring parameters relative to the path of the apparatus, and of computing a new control setpoint for the mobility of the apparatus depending on said parameters, this new control setpoint being determined by means of a controller that respects a model that limits the variation in the control setpoint.