Electric Bicycle Torque Sensor Redundancy for Continuous Motor Support
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Solution Overview
Problem
Existing torque sensor systems in vehicles, particularly electric bicycles, are prone to errors due to external influences and intrinsic malfunctions, leading to frequent interruptions in motor support and unsafe driving conditions.
Innovation Solution
Implementing multiple independent torque sensors and a control unit that generates a substitute control signal based on plausible torque measuring signals, using threshold values and periodicity criteria to ensure continuous motor support even in the presence of sensor errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single torque sensor is used to detect rider torque, then the device complexity is reduced, but the reliability of motor support is worsened due to sensor errors and malfunctions
Solution Approach 1:
The patent divides the torque detection function into multiple independent channels by using multiple torque sensors (at least two) that independently detect torque. This segmentation allows the system to identify and compensate for errors in individual sensors while maintaining overall system reliability through redundancy.
Solution Approach 2:
The patent changes the operational parameters of the torque sensor system by introducing threshold values for torque measurements and using periodicity criteria to validate sensor signals. This allows the control unit to distinguish between valid torque variations and error conditions, maintaining reliable motor support even when individual sensors fail.
2Measurement precision
If torque sensor sensitivity is increased to improve detection precision, then measurement precision is improved, but the reliability is worsened due to increased error proneness and susceptibility to external influences
Solution Approach 1:
The patent implements a feedback mechanism where the control unit continuously monitors torque measuring signals from multiple sensors, compares them against threshold values and periodicity criteria, and adjusts motor support accordingly. This feedback loop allows the system to maintain precise torque detection while compensating for sensor errors and external influences.
Solution Approach 2:
The system performs self-validation by using periodicity criteria to automatically distinguish between valid torque signals (which exhibit regular periodic patterns corresponding to pedaling) and error signals. This self-service approach allows the system to maintain reliable operation without external intervention even when individual sensors are affected by external influences.
3Reliability
If multiple independent torque sensors are implemented to improve reliability, then the reliability of motor support is improved, but the device complexity increases
Solution Approach 1:
The patent merges the functionality of multiple torque sensors into a unified control system that processes signals from all sensors through a single control unit. This merging approach maintains the reliability benefits of multiple sensors while reducing overall system complexity by using a centralized evaluation and decision-making structure.
4Measurement precision
If torque sensor evaluation is made more sensitive to detect errors, then measurement precision is improved, but productivity is worsened due to frequent interruptions in motor support
Solution Approach 1:
The patent applies preliminary action by establishing threshold values and periodicity criteria before error detection occurs. These pre-defined parameters allow the control unit to quickly and accurately evaluate torque signals, distinguishing between valid variations and actual errors without requiring complex real-time analysis, thus maintaining both detection precision and operational continuity.
Data Source
AI summary
A method for operating a vehicle operable by motor power and/or pedal power, in particular, an electric bicycle. The vehicle includes an electric drive, a crank mechanism, at least one torque sensor, which is configured to detect a torque applied by a rider onto the crank mechanism, in the form of a multitude of torque measuring signals, and a control unit, which is configured to generate a control signal for activating the electric drive as a function of at least one of the torque measuring signals. Upon detection of an error regarding the torque sensor, the control signal is generated in the form of a substitute control signal, based on at least one of the torque measuring signals, when this at least one torque measuring signal is recognized as plausible. A vehicle operable by motor power and/or pedal power, in particular, an electric bicycle, is also described.