Adaptive Motor Torque Control for Steering Feel During Auto-Steering Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The cancellation of automatic steering in existing vehicle control systems often results in temporary unintended steering wheel motions and a deterioration of steering feel, depending on the steering state at the time of cancellation.
Innovation Solution
A vehicle control system that adjusts the change rate of motor torque for an electric motor to approximate it to assist torque based on the relationship between motor torque and assist torque, as well as the change in turning angle, after automatic steering is cancelled, thereby preventing the deterioration of steering feel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the motor torque is gradually approximated to the assist torque when automatic steering is cancelled, then the steering wheel makes temporary unintended motions, but the steering feeling is deteriorated
Solution Approach 1:
The patent applies dynamics by making the motor torque change rate adaptive rather than fixed. The control system dynamically adjusts the approximation rate based on real-time steering state parameters (current motor torque, assist torque, and steering angle change rate), allowing the system to optimize both control stability and steering feeling under different operating conditions.
Solution Approach 2:
The patent changes the parameter of motor torque change rate based on multiple parameters including the relationship between motor torque and assist torque, and the change rate of steering angle. By adjusting this parameter dynamically, the system resolves the contradiction between preventing unintended motions and maintaining natural steering feeling.
2Device complexity
If a fixed change rate is used for motor torque approximation, then the control is simple, but the steering feeling deteriorates depending on steering state
Solution Approach 1:
The system transitions from static to dynamic control by continuously adjusting the motor torque change rate based on real-time steering conditions. This dynamic adaptation improves steering feeling across different operating states while adding controlled complexity to the control logic.
Solution Approach 2:
The control system uses feedback from steering state parameters (motor torque, assist torque, steering angle change rate) to adjust the motor torque approximation process. This feedback mechanism enables the system to adapt to different steering conditions and maintain optimal steering feeling.
3Speed
If the motor torque is quickly adjusted to match assist torque, then the response is fast, but the steering wheel makes unintended motions
Solution Approach 1:
The system dynamically adjusts the torque response speed based on steering conditions. Rather than using a fixed fast or slow rate, the motor torque change rate is continuously optimized based on the relationship between motor torque and assist torque, as well as the steering angle change rate, achieving both fast response and stability.
Solution Approach 2:
The patent changes the motor torque approximation rate parameter based on multiple steering state parameters. This parameter adaptation allows the system to achieve fast torque response when appropriate while preventing unintended steering wheel motions through context-aware adjustment.
Data Source
AI summary
A motor torque control section switches a change rate of a motor torque for approximating the motor torque to an assist torque according to relationship between the motor torque of an electric motor and the assist torque and according to a change in a turning angle, after automatic steering is cancelled according to a steering torque.