Bicycle Detector Using Magnetic Field Perturbation for Chain Position
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Solution Overview
Problem
Existing bicycle systems lack an efficient method to detect the movement and position of movable elements, such as the motion transmission chain and brake cables, which is crucial for gear shifting, braking, and energy management, as current solutions require continuous power consumption for wireless communication and may not accurately determine the movement of these elements.
Innovation Solution
A detector system using a magnet and magnetic field sensor, with associated electronics, to determine the presence and movement of non-diamagnetic movable elements by detecting perturbations in the magnetic field, allowing for direct monitoring of the chain and brake cable movement, and potentially estimating speed and position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If wireless communication systems are continuously activated for monitoring bicycle components, then real-time data transmission is achieved, but power consumption increases
Solution Approach 1:
The system uses periodic magnetic field sensing to detect chain movement, activating wireless communication only when movement is detected rather than continuous monitoring. The magnetic field sensor periodically checks for chain presence and triggers data transmission only when the chain moves between sprockets,实现间歇式工作模式
Solution Approach 2:
The magnetic field sensor autonomously detects chain movement and automatically triggers the wireless communication system without requiring continuous power supply to the communication module. The system serves itself by using passive magnetic field detection to activate active communication only when needed
2Use of energy by moving object
If magnetic field sensors are used to detect chain movement, then power consumption is reduced, but detection accuracy may be affected by environmental magnetic interference
Solution Approach 1:
The system uses feedback from the magnetic field sensor to continuously monitor chain position and detect changes. When the sensor detects a change in magnetic field pattern indicating chain movement, it triggers a feedback loop that activates the wireless communication system to report the gear shift event, ensuring reliable detection while maintaining low power consumption
Solution Approach 2:
The magnetic field acts as an intermediary between the chain movement and the detection system. Instead of directly measuring mechanical movement, the system uses the magnetic field as a mediator to detect chain presence and movement, providing indirect but reliable measurement that is less susceptible to mechanical interference
3Measurement precision
If continuous monitoring of chain position is implemented, then gear shifting accuracy is improved, but system complexity increases
Solution Approach 1:
The system extracts only the essential information needed for gear shifting detection - the presence and movement of the chain relative to sprockets - using a simple magnetic field sensor. Rather than implementing continuous comprehensive monitoring of all bicycle components, it focuses specifically on extracting chain position data when needed, simplifying the overall system while maintaining gear shifting accuracy
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 solution enables efficient detection of chain and brake cable movement, reducing power consumption by only activating necessary systems during use, preventing damage from incorrect gear shifts and optimizing braking systems, while providing accurate and direct monitoring of bicycle components.
Implementation Method 1
a magnet (12) that generates a magnetic field and a magnetic field sensor (14), wherein the mutual position of the magnet (12) and of the sensor (14) is fixed and the sensor (14) is immersed in the generated magnetic field
Data Source
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AI summary
A detector (10) for a bicycle, comprising: - a magnet (12) that generates a generated magnetic field and - a magnetic field sensor (14), characterized in that the mutual position of the magnet (12) and of the sensor (14) is fixed, and the sensor (14) is immersed in the generated magnetic field, wherein a length (140) of a path (130) intended for a non-diamagnetic movable element is immersed in the generated magnetic field, so that, if in said path length (140) there is at least one actual portion of the movable element, the sensor (14) detects the magnetic field perturbed by said actual portion of the movable element. A bicycle equipment and a bicycle derailleur are also described.