Bicycle Pedal Displacement Sensing for Accurate Exercise Measurement
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Solution Overview
Problem
Conventional bicycle pedals cannot accurately measure the quantity of exercise due to variations in force applied by the rider, especially when riding uphill or indoors with different loads, as they rely solely on RPM measurements.
Innovation Solution
A bicycle pedal design featuring a displacement generation assembly and a sensing unit that moves along a predetermined trajectory, allowing precise detection of rotation angle and linear displacement, independent of the spindle and pivot shaft rotation, to measure the applied force accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the quantity of exercise is measured based on RPM of the pedal, then the measurement is simple, but the accuracy is insufficient when load or terrain varies
Solution Approach 1:
The pedal system is segmented into distinct functional components: the case rotating around the spindle, the upper plate rotating around the pivot shaft, and the displacement generation assembly linking them. This segmentation allows independent measurement of rotational movements at different levels, enabling accurate exercise quantity calculation while maintaining a manageable structure.
Solution Approach 2:
The displacement generation assembly acts as an intermediary mechanism between the case and upper plate. It converts the rotational movement of the upper plate relative to the case into linear displacement that can be detected by the sensing unit, thereby enabling accurate measurement without directly complicating the pedal's main structure.
2Measurement precision
If a sensing unit is added to measure displacement accurately, then measurement precision improves, but device complexity increases
Solution Approach 1:
The displacement generation assembly merges the functions of measuring upper plate rotation and generating detectable linear displacement into a single integrated mechanism. By combining these functions, the patent reduces the need for separate sensing mechanisms while maintaining high measurement precision.
Solution Approach 2:
The displacement generation assembly utilizes the existing rotational movement of the upper plate to automatically generate the linear displacement needed for sensing. The mechanism serves itself by converting its own motion into a measurable form, eliminating the need for additional active components or complex sensing systems.
3Measurement precision
If the upper plate rotation is measured relative to the case, then the measurement accounts for load variations, but the structure becomes more complex
Solution Approach 1:
The patent extracts the measurement function from the main pedal structure by using the displacement generation assembly to isolate and measure only the relevant rotational movement of the upper plate relative to the case. This extraction allows accurate measurement of exercise quantity under varying loads without requiring the entire pedal structure to be redesigned.
Data Source
AI summary
A pedal for a bicycle is disclosed. The pedal for a bicycle comprises a case which can rotate about a spindle; a top plate which is connected to the case by a pivot shaft and can rotate about the pivot shaft; a displacement generating assembly which is disposed in the case and is connected to the case and the top plate so as to generate displacement according to the rotation of the top plate; and a sensing unit which is connected to the displacement generating assembly so as to sense the displacement.