Electric Bicycle Drive Unit Assistance Suspension by Torque Thresholds
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Solution Overview
Problem
Existing electric bicycles face a compromise between high riding comfort and efficiency, with motor support often maintained at a low level even when minimal power is required, leading to unnecessary energy consumption and noise.
Innovation Solution
A method that suspends drive unit assistance when rider torque or power falls below certain thresholds, with adjustable delay times and hysteresis to prevent frequent switching, allowing early deactivation for energy savings and quiet operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If motor support is maintained at a low level continuously, then riding comfort is improved, but energy consumption increases and range decreases
Solution Approach 1:
The patent applies dynamics by making the motor support level variable rather than fixed. The control unit dynamically adjusts the motor torque based on real-time monitoring of rider torque, switching between different support levels (first, second, third levels with different torque factors) and between active support and suspended support modes. This dynamic adaptation allows the system to provide optimal comfort only when needed while conserving energy during low-demand periods.
Solution Approach 2:
The patent implements feedback control by continuously monitoring the rider torque via a torque sensor and using this information to adjust motor support. The control unit receives feedback about the rider's pedaling effort and automatically adjusts the motor torque accordingly. This closed-loop feedback system ensures that motor support is maintained at appropriate levels based on actual riding conditions, preventing unnecessary energy consumption while maintaining comfort when required.
2Use of energy by moving object
If motor support is suspended early to save energy, then energy efficiency improves, but rider support may be insufficient
Solution Approach 1:
The patent applies dynamics by implementing multiple support levels (first, second, and third levels) with progressively decreasing torque factors. When suspending support, the system transitions through these levels rather than abrupt shutdown, allowing gradual reduction of motor torque. This dynamic transition ensures that rider support remains sufficient during the suspension process while still achieving energy savings compared to continuous full support.
Solution Approach 2:
The patent applies preliminary action by implementing delay times before suspending motor support when rider torque falls below threshold values. The control unit waits for a predetermined delay period before actually suspending support, allowing the rider time to increase pedaling effort if needed. This preliminary waiting period prevents premature suspension that would compromise rider support while still enabling energy savings when the rider consistently maintains low torque.
3Use of energy by moving object
If drive unit is switched off frequently to save energy, then energy consumption decreases, but switching frequency increases system complexity
Solution Approach 1:
The patent applies segmentation by dividing the motor support into three distinct levels (first level with highest torque factor, second level with intermediate torque factor, third level with lowest torque factor). This segmentation allows the control unit to manage switching between discrete, well-defined states rather than continuous adjustment, simplifying the control logic. The segmented approach reduces the complexity of determining when and how to switch while still enabling significant energy savings through appropriate level selection.
Solution Approach 2:
The patent replaces complex mechanical control mechanisms with electronic control. Instead of using mechanical switches or complex mechanical systems to manage motor support levels, the invention uses an electronic control unit that processes torque sensor signals and electronically adjusts motor torque through software logic. This substitution of electronic control for mechanical control significantly reduces system complexity while enabling flexible and efficient management of multiple support levels and suspension decisions.
4Ease of operation
If motor support is maintained during low torque periods, then rider comfort is improved, but noise increases
Solution Approach 1:
The patent applies dynamics by making motor support adaptive rather than static. The control unit dynamically adjusts motor torque based on real-time rider torque monitoring, suspending or reducing support when rider torque falls below threshold values. This dynamic adaptation allows the system to minimize noise by reducing or eliminating motor operation during low-demand periods while maintaining comfort when the rider needs support, effectively balancing noise reduction with rider comfort needs.
Data Source
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AI summary
Method for operating a drive unit of an electric bicycle, comprising the steps of: - determining a driver torque, - determining a driver power, - suspending support of the drive unit when the driver torque reaches or falls below a first threshold value, or - suspending support of the drive unit when the driver power reaches or falls below a first threshold value, wherein the suspension of support of the drive unit occurs in the event that the driver torque reaches or falls below the first threshold value after a first delay time TT1, or in the event that the driver power reaches or falls below the first threshold value after a first delay time TP1.