Turning Control Device Terminal Position Learning
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Solution Overview
Problem
The existing turning control devices face errors between virtual and actual rack end positions due to elastic bodies and looseness in the steering mechanism, leading to increased impact and abnormal noise during end-abutting, which cannot be effectively mitigated by increasing steering reaction force.
Innovation Solution
A turning control device with a position detection unit and a terminal position learning unit that includes multiple storage units to accurately learn and correct the terminal positions, reducing the influence of torsion and error by selecting the steered position farther from the neutral position, thereby minimizing the gap between virtual and actual rack end positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If steering reaction force is increased before the steering angle reaches the virtual rack end position, then impact and abnormal noise at the time of end-abutting should be mitigated, but error between virtual rack end position and actual rack end position causes desired output cannot be acquired and more-than-expected impact and abnormal noise occur
Solution Approach 1:
The terminal position learning unit continuously monitors the actual rack end position through the position detection unit and compares it with the learned terminal position. When a discrepancy is detected, the system updates the learned terminal position to match the actual position, creating a feedback loop that maintains high measurement precision and ensures accurate impact mitigation control.
Solution Approach 2:
The system automatically learns and updates the terminal position without requiring external intervention or manual calibration. The terminal position learning unit autonomously monitors the rack end position, detects deviations, and corrects the learned position values, enabling the system to self-adjust and maintain accuracy under varying operating conditions.
2Adaptability or versatility
If elastic bodies and looseness exist in the steering mechanism, then the steering mechanism can accommodate normal operational variations, but error occurs between virtual rack end position and actual rack end position
Solution Approach 1:
The terminal position learning unit proactively monitors and learns the actual terminal position before end-abutting occurs. By continuously tracking the rack end position and updating the learned terminal position in advance, the system compensates for elastic deformations and looseness that may develop during operation, ensuring that the virtual rack end position remains accurately aligned with the actual position.
Solution Approach 2:
The system dynamically adjusts the learned terminal position parameter based on detected deviations caused by elastic bodies and looseness. When the actual rack end position differs from the learned position, the system updates the terminal position parameter to reflect the current actual position, allowing the control system to adapt to changing mechanical conditions while maintaining measurement precision.
Data Source
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AI summary
To reduce error between virtual rack end positions and actual rack end positions. A terminal position learning unit (46) includes a first storage unit (72) configured to store a steered position positioned farthest from a neutral position of a turning mechanism within a range of a steered position detected by a position detection unit (14) when rotational force applied to the turning mechanism is less than or equal to a first predetermined value, a second storage unit (76) configured to store a steered position positioned farthest from the neutral position within a range of a position to which a steered position detected by the position detection unit (14) is shifted in a direction toward the neutral position of the turning mechanism by a second predetermined value, and a third storage unit (78) configured to store, as a terminal position stored by the terminal position learning unit (46), one of the steered positions stored in the first storage unit (72) and the second storage unit (76) positioned farther from the neutral position than the other.