Electric Motor Torque Coordination During Vehicle Gear Shifts
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Solution Overview
Problem
Existing gear control systems for vehicles with both rider-driven and electric motor-assisted propulsion face challenges in noise reduction and component protection during gear changes, as they cannot effectively coordinate the torque provided by both sources, leading to potential damage and noise.
Innovation Solution
A control unit that reduces the electric motor's torque contribution during gear changes by detecting when the rider's torque falls below a threshold, ensuring the motor supports the vehicle only after the gear change is complete, and using sensors to manage torque and position for precise coordination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the electric motor provides torque during gear changes, then the vehicle maintains driving force, but noise increases and mechanical components may be damaged
Solution Approach 1:
The control unit detects the gear change state in advance and reduces the electric motor's torque output before the gear change is fully executed. This preliminary reduction of torque prevents the motor from contributing to the harmful forces during the vulnerable gear shifting period, thereby reducing noise and preventing component damage while maintaining vehicle control
Solution Approach 2:
The control unit acts as an intermediary between the rider's drive input and the electric motor's torque output. It monitors the gear change state and mediates the motor's torque contribution, reducing it during gear changes and restoring it after gear changes, thus preventing the motor from directly causing the harmful effects while preserving its beneficial power assistance function
2Object-affected harmful factors
If the electric motor torque is reduced during gear changes, then noise and component damage are reduced, but the vehicle loses supporting drive force
Solution Approach 1:
The control unit applies periodic modulation to the electric motor's torque output based on the gear change cycle. During the gear change period, torque is reduced; after the gear change completes, torque is restored. This periodic adjustment ensures the motor provides power assistance when safe to do so while avoiding harmful effects during vulnerable operations
Solution Approach 2:
The control unit restores the electric motor's torque output after detecting that the gear change has completed. This restoration of torque ensures the motor resumes providing supporting drive force promptly after the vulnerable gear shifting period, minimizing the duration of reduced power assistance
Data Source
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AI summary
The application relates to a control unit for a vehicle and a method for changing gears of a vehicle. The vehicle comprises a drive provided by a rider and an electric motor, which supports the drive of the vehicle if gear is engaged. A control unit is connected with the electric motor and controls the torque provided by the electric motor such that the torque provided by the electric motor is reduced during a gear change.