Steering Actuator Degradation Detection via Dynamic Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing steering systems for vehicles face challenges in accurately determining the degradation level of the steering actuator, which is crucial for maintaining optimal performance and preventing erroneous detection.
Innovation Solution
A steering system that includes a controller to calculate an evaluation value based on the use state of the steering actuator and compare it with thresholds set according to the moving amount of the rack shaft and vehicle speed, allowing for accurate determination of the degradation level by suspending determination during high rack shaft speeds and adjusting thresholds based on vehicle speed and temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed threshold is used to determine degradation level, then the determination process is simple, but the accuracy of degradation determination decreases under varying vehicle conditions
Solution Approach 1:
The patent applies dynamics by making the threshold variable rather than fixed. The threshold is dynamically adjusted based on vehicle speed and rack shaft moving amount, allowing the degradation determination system to adapt to different operating conditions. This resolves the contradiction by improving measurement precision through dynamic adaptation while managing complexity through a systematic adjustment approach.
Solution Approach 2:
The patent changes the parameters used for threshold determination from static to dynamic values. By using vehicle speed and rack shaft moving amount as variable parameters, the system can accurately determine degradation levels across different operating conditions. This principle resolves the contradiction by improving accuracy through parameter variation while maintaining manageable complexity through defined adjustment rules.
2Measurement precision
If degradation determination is performed continuously, then the detection accuracy is high, but erroneous detection increases under certain conditions
Solution Approach 1:
The patent applies preliminary action by determining the rack shaft moving amount and vehicle speed before performing degradation determination. This preliminary assessment allows the system to set appropriate thresholds and determine whether to perform degradation evaluation, preventing erroneous detection while maintaining high detection accuracy when conditions are appropriate.
Solution Approach 2:
The patent uses feedback by continuously monitoring rack shaft position and vehicle speed, and using this information to adjust the degradation determination process. The system feeds back the moving amount and speed information to modify threshold settings and determination timing, improving both accuracy and reliability by avoiding false positives.
3Measurement precision
If the threshold is adjusted based on vehicle conditions, then the degradation determination becomes more accurate, but the calculation complexity increases
Solution Approach 1:
The patent applies dynamics by implementing dynamic threshold adjustment based on vehicle speed and rack shaft moving amount. The controller automatically adapts thresholds to current operating conditions, improving degradation determination accuracy while managing calculation complexity through systematic adjustment rules that scale with operating conditions.
Data Source
AI summary
Provided is a steering system for a vehicle that can accurately determine a degradation level of a steering actuator according to a traveling state of the vehicle. The steering system for the vehicle includes; a steering mechanism configured to steer wheels; a steering actuator configured to apply a driving force to the steering mechanism; and a controller configured to control the steering actuator. The steering mechanism includes a rack shaft that is movable in a vehicle width direction from a prescribed reference position. The controller is configured to calculate an evaluation value according to a use state of the steering actuator and to determine a degradation level of the steering actuator by comparing the evaluation value with at least one threshold that is set based on a moving amount of the rack shaft from the reference position and a vehicle speed.