Rotation Detection Device Abnormality Recovery Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotation angle detection devices face challenges in recovering from temporary abnormalities caused by noise affecting communication between the sensor and control unit, leading to instability in rotation detection.
Innovation Solution
The rotation detection device employs a stored value of absolute angle calculated before the abnormality, allowing it to recover and return to a normal state by using a recovery-time absolute angle calculation once the abnormality is resolved, ensuring continuous accurate detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the rotation angle detection device uses a rotation angle sensor to detect motor rotation, then rotation position information can be obtained, but temporary abnormalities caused by noise may occur during communication between the sensor and control unit
Solution Approach 1:
The control unit stores the last valid absolute angle value before an abnormality occurs. When noise causes temporary communication failure, the stored value serves as a backup, allowing the system to maintain accurate rotation detection without interruption until communication is restored.
2Productivity
If the device continues operation during abnormality, then productivity is maintained, but detection accuracy may be compromised without proper recovery mechanism
Solution Approach 1:
The control unit continuously monitors communication status between the rotation angle sensor and control unit. When communication is restored after an abnormality, the system detects the recovery and automatically switches back to using real-time sensor data, ensuring that accurate detection resumes without manual intervention.
3Reliability
If the system implements abnormality recovery using stored absolute angle values, then reliability is improved, but device complexity increases
Solution Approach 1:
The control unit autonomously manages the detection of abnormalities, stores valid data during normal operation, and automatically recovers when communication is restored. The system performs these functions without external intervention, and the complexity is justified by the significant improvement in detection reliability and continuous operation capability.
Data Source
AI summary
An electric power steering apparatus has a rotation detection device that can recover from abnormalities in calculating an absolute angle. The rotation detection device includes a signal acquirer that acquires a mechanical angle and a count value from a sensor, and an absolute angle calculator that calculates an absolute angle based on the mechanical angle and the count value. The rotation detection device further includes an abnormality determiner that determines abnormalities in the calculation of the absolute angle. The absolute angle calculator stores an absolute angle hold value prior to the detection of the abnormality the absolute angle. When the abnormality of the absolute angle is resolved, the absolute angle calculator calculates a recovery-time absolute angle, and returns to a normal-time absolute angle calculation.