Electric Motor Shaft Coupling via Closed-Loop Speed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for coupling an electric motor shaft with a wheel shaft in hybrid vehicles often result in jolting due to speed mismatches and require mechanical synchronization devices, which are inefficient and costly.
Innovation Solution
A closed-loop control method that measures the speed of the electric motor and wheel shaft, formulating operating setpoints through integration and anticipation to achieve synchronized speeds without mechanical synchronizers, using coefficients to adjust and stabilize the motor speed for smooth coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical synchronization device is used to equalize speeds during coupling, then coupling smoothness is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the mechanical synchronization device with an electronic control system that uses sensors to detect shaft speeds and a controller to regulate the electric motor speed, thereby eliminating complex mechanical components while achieving smooth coupling
Solution Approach 2:
The patent implements a feedback control system where sensors continuously monitor the speeds of the electric motor shaft and wheel shaft, and the controller adjusts the motor speed in real-time based on the detected speed difference, ensuring smooth coupling without mechanical synchronizers
2Productivity
If the electric motor speed is quickly increased to match wheel shaft speed, then coupling speed is improved, but speed overshoot occurs causing jolting
Solution Approach 1:
The feedback control system continuously monitors the actual motor speed and compares it with the target speed, adjusting the motor output in real-time to prevent overshoot and maintain stable speed matching during coupling
Solution Approach 2:
The patent dynamically adjusts the motor speed control parameters during the coupling process, transitioning from rapid acceleration to precise speed matching, thereby achieving both fast coupling and smooth operation without jolting
Data Source
AI summary
A method and device for coupling an electric motor shaft with a wheel shaft of a vehicle includes measurement of rotation speed of the electric motor and measurement of rotation speed of the wheels. The method also includes formulating via a closed-loop control a first operating setpoint for the electric motor based on the measured rotation speed of the electric motor and the measured rotation speed of the wheels; formulating a second operating setpoint based on the measured rotation speed of the wheels to which at least one coefficient is applied; controlling the operation of the motor around a final operating setpoint formulated based on adding together the first and second operating setpoints; and coupling, if the measured speed of the wheels to which the at least one coefficient is applied is equal to the measured speed of the motor, the electric motor shaft with the wheel shaft.