MITIGATION OF VEHICLE VIBRATIONS INDUCED BY DRIVE-LINE OSCILLATIONS

An electric motor controller is equipped to mitigate drive line induced vehicle vibration. The motor speed is measured at the output of the motor, separately from any measurement of drive shaft or wheel speed. At least bandpass filtering is applied to the measured motor speed, at a pass band based on the natural frequency of the drive shaft. The filtering detects drive line induced oscillations of the motor speed. A controller uses the detected drive line induced oscillations to generate an oscillation control output, subject to limiting. An oscillation mitigation torque signal corresponding to the control output is added to a torque command for desired motor speed, to adjust for the oscillations. The adjusted torque command is used to control the motor, with a significant reduction in the oscillation of the motor's speed.