Steering Angle Sensor Signal Correlation for Sensor IC Fault Diagnosis
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Solution Overview
Problem
Existing methods fail to diagnose malfunctions of steering angle sensors caused by sensor IC malfunctions in normal gear mesh conditions without damage to the gear teeth, as they cannot differentiate between incorrect angle outputs due to gear dislocation and sensor malfunctions.
Innovation Solution
An apparatus and method that includes a processor to compare output signal values from position sensors attached to sub-gears meshed with a main gear, determining malfunctions by identifying discrepancies in signal values corresponding to the same system angle, using pre-stored values in a table or map, and applying error range calculations to diagnose abnormal sensor behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If simple output comparison is used, then diagnostic simplicity is improved, but malfunction detection accuracy deteriorates
Solution Approach 1:
The patent implements feedback through correlation coefficient calculation, where the relationship between main gear and sub-gear signals is continuously evaluated. This feedback mechanism provides quantitative accuracy in detecting sensor malfunctions while maintaining operational simplicity through automated processor-based analysis.
Solution Approach 2:
The patent transforms the diagnostic approach by changing from direct signal value comparison to correlation coefficient analysis. This parameter transformation enhances detection accuracy by measuring the relationship strength between signals rather than absolute value differences, while the processor automation maintains ease of operation.
Data Source
AI summary
An apparatus for diagnosing malfunction of a steering angle sensor. A steering angle sensor includes a main gear mounted on a steering shaft, first and second sub-gears meshed with the main gear at a specific gear ratio different from that of the main gear, and position sensors attached to the first and second sub-gears, respectively. A processor receives a signal output with rotation of the corresponding sub-gear from each of the position sensors of the steering angle sensor, detects at least one of the two position sensors which outputs different output signal values that are not designated in correspondence with a value of the same system angle, and determines the detected at least one position sensor as a cause of a malfunction.