Motor-Driven Power Steering Torque Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The motor-driven power steering system experiences changes in steering feeling due to abrasion and degradation of components, as well as manufacturing variations, leading to inconsistent mechanical friction, which affects the driver's steering experience.
Innovation Solution
A control method and apparatus that calculate a torque compensation amount by comparing the change ratio of steering torque or rack thrust value with respect to the steering angle at different time points, allowing for real-time compensation of driver input torque to maintain initial steering feeling by adjusting the motor control values based on learned data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the motor-driven power steering system is used over time, then the steering assistance function is provided, but the steering feeling changes due to component abrasion and degradation
Solution Approach 1:
The controller performs preliminary learning of the gradient value between steering torque and steering angle during the initial period when components are in good condition. This learned gradient value serves as a reference for future compensation, allowing the system to predict and compensate for friction changes before they significantly affect steering feeling.
Solution Approach 2:
The system continuously monitors the actual steering torque and steering angle, calculates the real-time gradient value, and compares it with the learned reference gradient value. Based on the difference, the controller automatically compensates the driver input torque to maintain consistent steering feeling throughout the component's service life.
2Reliability
If the driver input torque is compensated in real-time, then the initial steering feeling is maintained, but the control system complexity increases
Solution Approach 1:
Instead of adding complex hardware components, the system maintains steering feeling consistency by dynamically adjusting control parameters (torque compensation value) based on the calculated gradient difference. This software-based approach achieves the goal without significantly increasing device complexity.
3Manufacturing precision
If the gradient value is learned and used for torque compensation, then manufacturing variations are compensated, but the calculation and control process becomes more complex
Solution Approach 1:
The system automatically learns the gradient value during normal operation and performs self-compensation without requiring manual calibration or adjustment. The controller autonomously adapts to manufacturing variations by continuously monitoring steering parameters and applying appropriate torque compensation, eliminating the need for complex manual setup procedures.
Data Source
AI summary
An apparatus and a method for controlling a motor-driven power steering system can inhibit a change in steering feeling which may be caused by abrasion and degradation of components in the motor-driven power steering system, and maintain initial steering feeling. The method determines a torque compensation amount by comparing a reference value with change ratio average data of steering torque with respect to a steering angle, and compensates for driver input torque in accordance with the determined torque compensation amount, such that it is possible to effectively inhibit the change in steering feeling which may be caused by abrasion and degradation of components, and maintain the initial steering feeling.