Abstract
Aiming at the Electric vehicles’ NVH problem under the condition of low vehicle speed, the vibration characteristics and control methods for the torsional vibration of powertrain and driveline systems are studied. A road test of torsional vibration of an electric vehicle powertrain has been conducted under medium and rapid acceleration. Motor torque and rotational speed, as well as the accelerations of motor shell and vehicle body have been measured and analyzed in time and frequency domain. According to the multibody dynamics, a rigid-flexible coupling model of powertrain and driveline systems has been established, and transient dynamics of the torsional vibration are analyzed by using the real torque measured as input. In order to suppress the torsional vibration, a torsional vibration absorber has been proposed, which connects the motor rotor and gear reducer. The influence of secondary moment of inertia, stiffness and damper on the resonant frequency are analyzed, and these parameters are optimized by GRG method. The simulation results show that this method can suppress the torsional vibration effectively.