Shift Range Control Apparatus Idling State Determination
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Solution Overview
Problem
Existing shift range control systems face challenges in accurately switching shift ranges due to play between the motor shaft and output shaft, leading to potential errors in motor rotation angle correction caused by noise in sensor detection.
Innovation Solution
A shift range control apparatus that determines the end of idling based on both motor and output shaft angles, using a corrected angle value to set a target motor angle for precise drive control, thereby reducing the need for high accuracy in output shaft sensor detection and minimizing errors from noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a motor shaft and output shaft connection system with play is used for shift range switching, then the system can accommodate mechanical tolerances and ease of assembly, but the rotation transmission accuracy deteriorates due to play between motor shaft and output shaft
Solution Approach 1:
The control device performs preliminary action by detecting the idling state of the motor shaft before actual rotation transmission begins. By identifying when the motor shaft is rotating within the play range and has not yet engaged the output shaft, the system can prepare and correct the target rotation angle in advance, ensuring accurate position control once engagement occurs.
Solution Approach 2:
The control device uses feedback from the motor shaft rotation angle detection to determine idling state and correct the target rotation angle. By continuously monitoring the motor shaft angle and comparing it with expected values, the system detects when play exists and adjusts the target angle accordingly to compensate for the mechanical clearance.
2Reliability
If output shaft sensor detection is used for correction control, then rotation position feedback is obtained, but detection errors due to noise increase correction inaccuracies
Solution Approach 1:
The control device uses the motor shaft rotation angle as an intermediary parameter to indirectly determine the output shaft position during idling state. Instead of relying solely on direct output shaft sensor detection which is susceptible to noise, the system uses motor shaft angle changes as a mediator to infer and correct the target rotation angle, reducing the impact of sensor noise on correction accuracy.
3Manufacturing precision
If target motor rotation angle correction is performed based on output shaft sensor detection, then position accuracy is improved, but erroneous corrections occur due to noise in sensor signals
Solution Approach 1:
The control device performs preliminary detection of the idling state before executing correction control. By determining whether the motor shaft is in idling state (rotating within play without engaging output shaft), the system activates correction only when necessary, preventing erroneous corrections during normal operation where sensor noise could cause false adjustments.
Solution Approach 2:
The control device dynamically adjusts the correction strategy based on the detected idling state. When idling is detected, the system applies target angle correction using motor shaft rotation information; when idling is not detected, normal sensor-based feedback control is used. This dynamic switching prevents erroneous corrections while maintaining position accuracy.
Data Source
AI summary
A shift range control apparatus includes: an idling determination portion that determines, based on a motor angle and an output shaft angle, an end of an idling state in which a motor is rotating within a range of a play, the motor angle being a value based on a detected value of a motor rotation angle sensor that detects the rotation of the motor, the output shaft angle being a value based on a detected value of an output shaft sensor that detects rotation of the output shaft; and a target value setting portion that sets a motor angle target value for drive control of the motor using a corrected angle value that is a value corresponding to the motor angle at an end of an idling.