Situation-Dependent Wheel Angle Controller Bandwidth Adaptation
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Solution Overview
Problem
Highly autonomous driving and advanced driver assistance systems require high bandwidth in wheel angle controllers for accurate path tracking, but this can result in uncomfortable and erratic steering, especially in situations with ample space, necessitating a solution that balances control speed and accuracy with comfort and smoothness.
Innovation Solution
An apparatus and method that adjust the bandwidth of the wheel angle controller based on internal state data, ambient information, and map data, using gain parameters to increase control speed and accuracy when necessary and reduce it when safe maneuvering space is ample, allowing for comfortable and steady control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high bandwidth is used in the wheel angle controller to improve path tracking accuracy and speed, then control precision and response time improve, but steering smoothness and comfort deteriorate
Solution Approach 1:
The patent implements dynamic adjustment of controller bandwidth based on driving situation. The control bandwidth is increased when path tracking precision is critical (e.g., narrow lanes, complex curves) and reduced when smoothness is prioritized (e.g., straight roads, wide lanes). This resolves the contradiction by making the controller adaptive rather than fixed, allowing high precision when needed while maintaining comfort during normal driving.
Solution Approach 2:
The patent changes the bandwidth parameter of the wheel angle controller based on detected driving conditions. By dynamically modifying this key control parameter, the system achieves high tracking accuracy when necessary while reducing control aggressiveness to maintain steering comfort, thus resolving the precision-comfort tradeoff.
2Reliability
If high bandwidth control is applied to ensure safe path tracking, then Automotive Safety Integrity requirements are met, but driver comfort and steering calmness deteriorate
Solution Approach 1:
The system dynamically adjusts control bandwidth based on real-time assessment of driving situation safety requirements. When safety-critical conditions are detected (narrow margins, complex geometry), high bandwidth ensures rapid response and precise tracking to meet safety integrity levels. When conditions permit, bandwidth is reduced to provide calmer, more comfortable steering, thus resolving the safety-comfort contradiction.
Solution Approach 2:
The control bandwidth parameter is dynamically modified based on safety requirements derived from driving situation analysis. This allows the system to guarantee high reliability when needed while maintaining ease of operation during less critical phases, resolving the contradiction between safety integrity and driver comfort.
3Speed
If increased control gain is used to improve response speed for path tracking, then tracking performance improves, but steering smoothness and calmness deteriorate
Solution Approach 1:
The patent implements dynamic adjustment of control gains based on driving situation. When rapid response is required (e.g., approaching curves, changing lane geometry), higher gains provide faster correction. When driving conditions are favorable (e.g., straight roads, wide lanes), lower gains maintain smooth, calm steering. This resolves the contradiction between response speed and smoothness through situation-dependent adaptation.
Solution Approach 2:
The control gain parameters are dynamically modified based on assessed driving conditions. By adjusting these parameters in real-time, the system achieves fast response when needed while maintaining smooth control during normal operation, resolving the speed-smoothness tradeoff.
Data Source
AI summary
An apparatus and method are described for situation dependent wheel angle (δw) control by a HAD or ADA system of a road vehicle, the HAD or ADA system configured to receive internal state data as well as ambient information or map data, and generates a penalty measure based thereupon. A lateral controller receives a desired path and outputs a wheel angle request (δw,r). A PSCM includes a wheel angle controller configured to receive the wheel angle request (δw,r), wheel angle (δw) and wheel angle rate ({dot over (δ)}w) data, and output an overlay torque request to a motor controller of a steering system. The lateral controller calculates gain parameters (Iδ<sub2>w</sub2>, I{dot over (δ)}<sub2>w</sub2>) based on the penalty measure and outputs these to the wheel angle controller. The wheel angle controller receives and uses the gain parameters (Iδ<sub2>w</sub2>, I{dot over (δ)}<sub2>w</sub2>) in control loops thereof to adjust the bandwidth of the wheel angle controller.