Shift Lever Position Sensing via Hall Sensor and Magnet
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Solution Overview
Problem
In vehicles with DCT, incorrect information from the inhibitor switch can lead to unsafe vehicle control, as the controller may inadvertently shift into reverse when the driver intends to shift into neutral, due to faulty signal transmission.
Innovation Solution
A shifting range sensing apparatus that includes a housing, a magnet, a power transfer unit, and a Hall sensor to accurately detect the shift lever's position, providing a secondary signal to the controller to ensure safe operation, even if the inhibitor switch fails, by using a connecting rod and arc slots to transmit the shift lever's rotation and sensing the magnet's movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cable is used to transmit shift lever operation to the inhibitor switch and manual valve, then the structure is simple and easy to manufacture, but the reliability is reduced because incorrect information from the inhibitor switch can lead to unsafe vehicle control
Solution Approach 1:
A magnet is introduced as an intermediary component that mechanically follows the shift lever's movement through a power transfer unit, while the Hall sensor detects the magnet's position without mechanical contact. This intermediary approach allows accurate position detection while isolating the electronic sensing system from mechanical wear and failure modes of direct mechanical linkages.
Solution Approach 2:
The patent replaces the traditional mechanical cable-based position transmission system with a magnetic field-based sensing system. The Hall sensor detects the magnet's position through magnetic field interaction, eliminating the need for physical cable connections and mechanical linkages between the shift lever and the sensing apparatus, thereby improving reliability.
2Reliability
If the controller relies solely on the inhibitor switch signal for shifting control, then the control system is simple, but the reliability deteriorates when the inhibitor switch transmits incorrect information due to failure
Solution Approach 1:
The system implements feedback by continuously monitoring the shift lever's actual position through the Hall sensor and comparing it with the inhibitor switch signals. The controller receives real-time position information from the Hall sensor, which provides feedback on the actual shift lever position, allowing the system to detect and correct discrepancies between the inhibitor switch signal and the actual position, thereby improving shifting control accuracy and reliability.
Solution Approach 2:
The Hall sensor continuously detects the shift lever's position in advance before any potential failure occurs in the inhibitor switch. This preliminary detection of the actual position allows the controller to anticipate and prevent unsafe operations by having accurate position information available before the inhibitor switch fails, enabling proactive safety measures.
3Measurement precision
If a Hall sensor and magnet system is implemented to detect shift lever position, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The magnet serves multiple functions: it is attached to the shift lever to follow its movement, acts as the target for the Hall sensor to detect position, and integrates with the power transfer unit to ensure accurate position tracking. This multi-functionality reduces the need for separate components and simplifies the overall structure despite the advanced sensing capability.
Solution Approach 2:
The patent merges the power transfer unit with the magnet assembly, where the magnet is integrated into the moving component that transmits shift lever motion. This merging of functions reduces the number of separate parts and simplifies the structure while maintaining high measurement precision through the Hall sensor-magnet system.
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
Ensures safe vehicle control by providing accurate shift range information, preventing unexpected vehicle reversals and enhancing driver safety by prioritizing the signal from the shifting range sensing apparatus over the inhibitor switch in case of a failure.
Implementation Method 1
a Hall sensor fixed in the housing to sense the movement of the magnet
Data Source
AI summary
A shifting range sensing system, may include a shift lever pivotally connected to a vehicle body, a shift range sensing apparatus to sense a pivotal movement of the shift lever, an inhibitor switch mounted in a transmission, and a controller taking an emergency measure when a signal of the inhibitor switch and a signal of the shifting range sensing apparatus do not indicate the same shifting range.