Steering Angle Sensor Zero Point Calibration via Rotational Displacement Difference
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Solution Overview
Problem
In vehicles equipped with motor-driven power steering (MDPS), the existing zero point calibration methods for steering angle sensors fail to accurately diagnose and automatically correct abnormal zero point settings in variable gear rack systems, leading to steering instability and requiring manual intervention.
Innovation Solution
A zero point calibration apparatus and method that calculates the rotational displacement difference between the steering angle and motor angle, determines the middle point of this difference, and adjusts the zero point of the steering angle sensor to compensate for shifts, using a control unit and sensors to automatically calibrate the sensor in real-time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If existing zero point calibration methods are used in variable gear rack systems, then the calibration process requires manual intervention and cannot automatically correct abnormal zero point settings, but this leads to steering instability and increased complexity in the calibration procedure
Solution Approach 1:
The patent implements feedback by continuously monitoring the rotational displacement difference between the steering angle sensor and motor angle sensor, comparing the middle point of this difference against the set zero point, and automatically adjusting the zero point when deviations are detected. This closed-loop feedback mechanism enables automatic calibration while ensuring steering stability through real-time correction of zero point abnormalities.
Solution Approach 2:
The calibration system performs self-service by automatically detecting zero point abnormalities through rotational displacement difference calculation, determining the middle point, and correcting the zero point without requiring manual intervention. The system serves itself by using its own sensors and control unit to identify and fix calibration issues, eliminating the need for external manual calibration procedures.
2Productivity
If manual intervention is required for zero point calibration, then the calibration process becomes time-consuming and complex, but this prevents real-time correction of zero point shifts
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the middle point of the rotational displacement difference pattern during system setup. This pre-established reference value enables rapid automatic comparison and calibration during operation, eliminating the need for time-consuming manual calibration procedures while allowing real-time correction of zero point shifts through automated processes.
3Reliability
If the zero point of the steering angle sensor is not accurately calibrated, then steering instability occurs, but manual calibration procedures increase operational complexity and require specialized intervention
Solution Approach 1:
The patent uses the middle point of the rotational displacement difference as an intermediary reference value that mediates between the steering angle sensor and motor angle sensor. This intermediary enables automatic comparison and zero point correction without requiring complex manual calibration procedures, thereby ensuring steering stability while simplifying the calibration process through automated intermediate calculation and adjustment.
Data Source
AI summary
A zero point calibration apparatus for a steering angle sensor using a rotational displacement difference includes: a steering angle sensor configured to sense a steering angle of a column in a steering apparatus for a vehicle; a motor angle sensor configured to sense a rotation angle of a motor which supports steering by the column in the steering apparatus; and a control unit configured to calculate a current rotational displacement difference pattern between the steering angle and the motor angle, and derive the middle point of the current rotational displacement difference pattern. When the middle point does not coincide with a zero point set in the steering angle sensor, the control unit determines that the zero point set in the steering angle sensor is abnormal, and calibrate the zero point.