E-Bike Motor Torque Control for Transmission Wear Reduction
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Solution Overview
Problem
The service life of two-wheeler transmissions, particularly in electric bicycles, is compromised due to increased wear and tear caused by high motor torque and rider pedaling force, leading to potential damage and reduced durability.
Innovation Solution
A control method for the drive motor that detects pedaling steps and gear wear, adjusting motor torque and speed to reduce transmission load, limiting torque to a maximum value when high wear is detected, and delaying full torque application after starting to extend transmission life without affecting riding comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If high motor torque is applied to improve starting comfort and acceleration performance, then the driving performance is improved, but the wear and tear of the transmission increases
Solution Approach 1:
The control device dynamically adjusts motor torque based on detected gear wear conditions. When high wear is detected, the system reduces motor torque to protect the transmission, while maintaining higher torque when wear is low to ensure starting comfort. This dynamic adaptation resolves the contradiction between transmission protection and driving performance.
Solution Approach 2:
The system changes the torque parameter based on gear wear detection. By monitoring transmission conditions and adjusting the torque parameter accordingly, the system optimizes both transmission longevity and starting comfort, resolving the contradiction between these two requirements.
2Reliability
If motor torque is limited to protect the transmission, then the transmission service life is extended, but the starting comfort and acceleration performance deteriorate
Solution Approach 1:
The control device performs preliminary detection of gear wear conditions before full torque application. By detecting transmission state in advance and pre-adjusting torque limits accordingly, the system prevents excessive wear while maintaining optimal starting comfort, resolving the contradiction between protection and performance.
Solution Approach 2:
The system implements feedback control by continuously monitoring gear wear conditions and adjusting motor torque based on detected transmission state. This closed-loop control ensures that torque is optimized for both transmission protection and starting comfort, resolving the contradiction between these opposing requirements.
3Speed
If full torque is applied immediately after starting to improve acceleration, then the acceleration performance is improved, but the transmission is subjected to excessive load and wear
Solution Approach 1:
The control device implements periodic torque application with delays after starting. Instead of immediate full torque, the system applies torque in controlled periods, allowing the transmission to settle and reducing initial wear shocks while maintaining acceleration performance, thus resolving the contradiction between acceleration and transmission durability.
Data Source
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AI summary
Control method for a drive motor (101) of a two-wheeler (100), wherein the two-wheeler (100) is configured to be driven at least partially by means of a pedaling force of the two-wheeler rider on pedals (103) of the two-wheeler (100) and by means of a motor torque of the drive motor (101), wherein the control method comprises the following steps: detection (310) of pedaling parameters representing the actuation of the pedals (103) by the two-wheeler rider, and determination (330) of a motor speed (n) of the drive motor (101), wherein the control method comprises the following steps: determination (340) of a gear wear of a transmission (102) as a function of the determined motor speed (n), and control (360) of the drive motor (101) as a function of the detected pedaling parameters and the determined gear wear.