EV Motor Torque Control for Gear Rattle Suppression
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Solution Overview
Problem
Electric vehicles experience significant vibration and noise due to gear rattling when the output torque of the motor changes between positive and negative torque, affecting driving comfort and potentially causing damage to transmission mechanisms.
Innovation Solution
A motor control method that detects relative deformation in the transmission system, determines a speed difference value when the driving gear disengages and re-contacts with the driven gear, and adjusts the output torque to control a tooth approaching operation, reducing the speed difference and associated vibration and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If filtering processing method is used to process output torque, then vibration and noise are reduced, but driving experience remains poor due to residual vibration and noise
Solution Approach 1:
The system performs preliminary detection of relative deformation in the transmission system to predict gear disengagement and re-contact events before they occur. By calculating speed difference values in advance and determining appropriate output torque values beforehand, the system proactively prevents gear rattling rather than merely filtering its effects after they manifest.
Solution Approach 2:
The system continuously detects relative deformation of the transmission system and uses this feedback to dynamically adjust the motor's output torque. The control method creates a closed-loop system where detection results directly influence torque adjustment, enabling real-time suppression of gear rattling and associated vibration and noise.
2Adaptability or versatility
If output torque changes between positive and negative torque, then motor can adapt to different driving conditions, but gear meshing direction changes cause gear rattling and vibration
Solution Approach 1:
The system dynamically changes the output torque parameter based on detected relative deformation and calculated speed difference values. By adjusting torque magnitude and direction in response to transmission system state changes, the system maintains motor adaptability to different driving conditions while preventing gear meshing direction changes that cause rattling.
Data Source
AI summary
The present application relates to an electric vehicle, a motor control method thereof, an apparatus and a storage medium. The motor control method of the electric vehicle of the present application includes: detecting a relative deformation of a transmission system between a driving gear and a wheel end of a motor; determining a first speed difference value of a first driving gear rotation speed and a first wheel end conversion rotation speed when the relative deformation is a first threshold, where the relative deformation being the first threshold value is used to indicate that the driving gear starts to disengage from a driven gear of the transmission system; determining an output torque of the motor according to the first speed difference value; and controlling the driving gear to perform a tooth approaching operation relative to the driven gear according the output torque.