Independent Wheel-Motor Torque Matching for EV Stability
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Solution Overview
Problem
Existing control systems for electric vehicles with multiple motors struggle to accurately control output torques due to varying motor characteristics caused by temperature changes, leading to reduced straight-running stability and turning performance.
Innovation Solution
A control system that includes a parameter estimator, a reference motor selector, and a motor torque controller to calculate and correct estimated parameters, reducing differences between motors to improve torque control accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional torque control is used without considering individual motor characteristics, then control simplicity is maintained, but torque control accuracy deteriorates due to temperature-induced flux changes
Solution Approach 1:
The control system performs self-service by automatically estimating each motor's output characteristics and temperature, then using this information to adjust torque commands without external intervention. This self-adjusting mechanism maintains torque control accuracy while keeping the control system relatively simple, as the estimation and compensation are performed autonomously by the control unit.
Data Source
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AI summary
A control system for an electric vehicle (Ve) configured to control output torques of each motor (1, 2, 3, 4) independently so as to improve a running stability and a control stability. Each of the motors (1, 2, 3, 4) is connected individually to one of wheels (11, 12, 13, 14) so that drive forces established by the wheels are controlled independently by controlling output torques of motors (1, 2, 3, 4) independently. A control unit (6) is configured to: calculate estimated parameters of the motors (1, 2, 3, 4); select a reference motor; calculate a difference between the estimated parameters of the reference motor (1, 2, 3, 4) and other motor (1, 2, 3, 4); and control the torques of the motors (1, 2, 3, 4) to reduce a difference between the torques of the reference motor (1, 2, 3, 4) and other motor (1, 2, 3, 4).