Automotive Transmission Shift Position Detection
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Solution Overview
Problem
Existing automatic-manual transmissions face challenges in accurately detecting the shift gear-in establishing position due to warping of the magnet holding structure, leading to inaccurate output data from magnetic sensors and inefficient gear shifting.
Innovation Solution
A shift position detecting device with a control unit that adjusts the shifting load to minimize warping effects, using a first shifting load to ensure gear positioning and a second lower load to stabilize the sensor output, allowing for accurate detection and storage of shift position data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetic sensor is used to detect shift position, then shift position detection is enabled, but warping of the magnet holding structure causes inaccurate sensor output
Solution Approach 1:
The control unit applies a first shifting load to the shift actuator before applying a second shifting load, to preliminarily position the gear selection mechanism at the shift gear-in establishing position. This preliminary positioning ensures the mechanism is correctly seated before the magnetic sensor takes the final measurement, compensating for potential warping effects.
Solution Approach 2:
The control unit continuously monitors the output data from the magnetic sensor and compares it against expected values. When the output data indicates the gear selection mechanism has reached the shift gear-in establishing position, the control unit confirms proper positioning. This feedback loop ensures accurate detection despite potential warping of the magnet holding structure.
2Manufacturing precision
If a high shifting load is applied to ensure gear positioning, then gear positioning accuracy is improved, but warping of the magnet holding structure increases
Solution Approach 1:
The shifting load application is segmented into two distinct phases: a first shifting load applied initially to ensure proper gear positioning, followed by a second shifting load applied after positioning is confirmed. This segmentation allows the system to achieve positioning accuracy without subjecting the magnet holding structure to continuous high load that would cause warping.
Solution Approach 2:
The control unit applies the first shifting load periodically to maintain proper gear positioning, then switches to the second shifting load. This periodic application of high load only when necessary minimizes cumulative warping effects on the magnet holding structure while maintaining positioning accuracy during critical operations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures accurate detection of shift positions by minimizing the impact of warping on sensor output, improving gear shifting precision and reducing costs associated with incorrect assembly and mounting.
Implementation Method 1
a magnetic sensor that senses a magnetic flux produced by the permanent magnet
Data Source
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AI summary
A shift position detecting device (17,21) comprises a shift position sensor (17) that continuously issues an output data that represents a shift position of the gear selection mechanism; and a control unit (21). The control unit (21) includes a first shifting load instruction section that controls the shift actuator to shift the gear selection mechanism to the shift gear-in establishing position with a first shifting load; a second shifting load instruction section that, after completion of shifting of the gear selection mechanism to the shift gear-in establishing position by the first shifting load instruction section, controls the shift actuator to reduce the shifting load from the first shifting load to a second shifting load which is lower than the first shifting load; and a shift gear-in establishing position memory section that stores an output data issued from the shift position sensor (17) when the shift actuator is controlled by the second shifting load instruction section, as an information data that represents completion of shifting of the gear selection mechanism to the shift gear-in establishing position.