Vehicular Shift Apparatus Sensor Matrix Design
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Solution Overview
Problem
Existing vehicular shift apparatuses face challenges in accurately sensing shift positions and intermediate positions due to the need for complex sensing element configurations and potential failures, especially when using a rotary knob or dial type operation member, which complicates the control system and reduces accuracy.
Innovation Solution
A vehicular shift apparatus with a dial-type operation member and nine contactless magnetic sensors arranged along the trajectory of a rotating magnet, allowing for accurate sensing of five shift positions and four intermediate positions, and enabling identification of the current shift position even if one sensing element fails by using a controller to interpret the combination of sensing outputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single magnetic sensor is used to sense shift positions, then the device complexity is reduced, but the measurement precision of shift positions deteriorates
Solution Approach 1:
The sensing system is segmented into multiple magnetic sensors (first through ninth sensors) arranged at different positions. Each sensor detects the presence or absence of the magnet at its specific location, and the combination of sensor outputs identifies the shift position. This segmentation enables precise detection of multiple shift positions and intermediate positions without requiring a single complex sensor.
2Measurement precision
If multiple sensing elements are arranged in a line to sense intermediate positions, then the measurement precision is improved, but the device complexity increases significantly
Solution Approach 1:
The magnetic sensors are arranged in a two-dimensional matrix pattern rather than a simple linear arrangement. This dimensional change allows the system to detect both shift positions and intermediate positions effectively. The matrix arrangement optimizes the spatial distribution of sensors, enabling precise position detection while managing device complexity through a structured geometric pattern.
3Device complexity
If a common sensing element is allocated to adjacent shift positions to reduce the number of sensors, then the device complexity is reduced, but the reliability deteriorates due to potential sensing element failure
Solution Approach 1:
Each magnetic sensor is assigned to detect specific shift positions or intermediate positions based on its local position in the matrix arrangement. The first and second sensors detect the drive position, third and fourth sensors detect the drive-side neutral position, and so on. This localized assignment ensures that each sensor contributes to detecting specific positions, and the system can identify shift positions reliably even if one sensor fails, as other sensors provide redundant detection capability.
4Ease of operation
If the angle of rotation of the rotary knob is small, then the ease of operation is improved, but the measurement precision of shift positions deteriorates
Solution Approach 1:
A magnet is introduced as an intermediary element attached to the rotary knob. The magnet rotates with the knob and passes by the magnetic sensors at specific angles corresponding to different shift positions. This intermediary magnet enables the sensors to detect precise angular positions of the knob even when the total rotation angle is small, as the magnet's position relative to each sensor provides accurate angular information.
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
The solution enhances the accuracy and reliability of shift position sensing, allowing for continuous normal operation even if one sensing element fails, and reduces the complexity of the control system by ensuring correct identification of shift positions based on current sensing results.
Implementation Method 1
the sensing element is placed on a board to face the magnet, and is configured to sense changes of magnetic flux of the magnet
Data Source
AI summary
A vehicular shift apparatus includes an operation member configured to be put in five shift positions including a home position, a drive position, a reverse position, a drive-side neutral position, and a reverse-side neutral position. Nine sensing elements are provided to sense a magnet moved by movement of the operation member. The home position is allocated with three sensing elements, and each of the remaining four shift positions is allocated with two sensing elements, wherein two of the sensing elements allocate to the home position are shared by other two of the shift positions. The five shift positions and four intermediate positions between respective two adjacent shift positions are determined, based on combination of outputs of the nine sensing elements.