Bicycle Wheel Speed Sensor with Adaptive Filter for Cadence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bicycle systems require separate sensors for measuring wheel speed and pedaling cadence, leading to increased weight, cost, and aesthetic issues due to visible components, especially when the gear ratio is variable.
Innovation Solution
A single sensor device that uses an inductive sensor with a phonic wheel and Hall effect sensor to detect angular speed, combined with an adaptive filter and extended Kalman filter for noise reduction and pedaling cadence estimation, allowing for lightweight and aesthetically pleasing installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate sensors are used for measuring wheel speed and pedaling cadence, then measurement accuracy is improved, but device weight and complexity increase
Solution Approach 1:
The patent combines two separate measurement functions (wheel speed sensing and pedaling cadence detection) into a single integrated sensor system. The Hall effect sensor simultaneously detects wheel rotation speed and, through signal processing of the same sensor output, determines pedaling cadence by analyzing frequency components related to pedal rotation.
Solution Approach 2:
The single sensor system performs multiple functions: it measures wheel angular speed directly and also extracts pedaling cadence information through signal analysis. The system universally handles both measurement tasks that traditionally required separate dedicated sensors.
2Reliability
If separate sensors are installed for wheel speed and pedaling cadence, then measurement reliability is improved, but device complexity and installation time increase
Solution Approach 1:
The patent merges two separate sensor installations into one integrated system. A single Hall effect sensor replaces what would traditionally require two separate sensors, reducing wiring complexity, installation steps, and potential failure points while maintaining measurement reliability through sophisticated signal processing.
Solution Approach 2:
The control unit acts as an intermediary that processes the single sensor's output signal to extract both wheel speed and pedaling cadence information. Through signal filtering and frequency analysis, the control unit mediates between the raw sensor data and the two different measurement objectives.
3Measurement precision
If cadence sensors are made visible for accurate detection, then measurement precision is improved, but aesthetic appearance deteriorates
Solution Approach 1:
The patent eliminates the need for visible cadence sensors by merging cadence detection functionality into the existing wheel speed sensor system. The same hidden sensor that measures wheel speed also provides cadence data through signal analysis, removing the aesthetic compromise entirely.
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
Enables accurate determination of both angular speed and pedaling cadence using a single sensor, reducing complexity and weight while improving aesthetic appeal by minimizing visible components.
Implementation Method 1
an angular speed sensor (2) adapted to be associated to said bicycle wheel and suitable for detecting the angular speed w of the wheel
Data Source
AI summary
A device for determining a kinematic magnitude of a bicycle and a rate of the pedal-thrust exerted by a user on the pedals of the bicycle includes a sensor of the bicycle, adapted to be associated to the bicycle, suitable for detecting the bicycle kinematic magnitude (ωi) and for generating a signal representative of the bicycle kinematic magnitude; a filter connected to the sensor of the bicycle kinematic magnitude, configured for receiving at the input the signal representative of the bicycle kinematic magnitude (ωi) and for supplying, at the output, an optimized signal (ωopt) of the bicycle kinematic magnitude; and a module for the frequency-analysis of the optimized signal (ωopt) of the bicycle kinematic magnitude, connected to the filter.