Torque ripple compensation control for hybrid UGVs in mode transition based on current harmonic control of a PMSM

Abstract

Load jumping and mode transitions both cause the unstable dynamic states for compound power-split hybrid Unmanned Ground Vehicles (UGVs), and these phenomena lead to vibrations of the transmission system and longitudinal buffeting of the vehicle. This study presents a feed-forward compensation control strategy for load jumping and mode transitions to reduce the corresponding torsional vibration in hybrid UGVs. The proposed method injects an appropriate harmonic current into a permanent magnet synchronous motor (PMSM) to generate a harmonic torque that is opposite to the load torque, which improves the dynamic response quality of the vehicle load. First, the multimode structure of a hybrid UGV and mode switching vibration and shock are investigated, as well as a feed-forward compensate control architecture is proposed. Second, two models are established the PMSM dynamic model based on the electromagnetic coupling principle and a 2-degree-of-freedom torsional vibration model of transmission system by simplifying the vehicle system. Third, the harmonic current injection method is proposed, and the harmonic current equation is derived. Based on the field-oriented control algorithm, a double closed-loop controller is designed for the torque and speed of the PMSM, and the internal model control method is applied to design the current controller. The simulation results show that the proposed strategy effectively suppresses jerk and that the harmonics current transfers the energy from the mechanical vibrations of the system into electric power fluctuations.

Master-slave synchronous control method for attenuating dual mode electromechanical transmission system torsional vibration

“…where h i is the sequence of weight coefficients. equation (31) shows that the estimation method of DC component estimated based on linear regression method has the form of FIR filter. By Z-transform of equation ( 31), it can be obtained that the discrete transfer function of the low-pass filter is H lp ðzÞ ¼ H reg ðzÞ ¼…”

“…According to the principle of nonlinear observer and model-based torque estimator, Zeng et al 30 designed a dynamic coordination strategy based on predictive model to realize the smooth switching from EVT mode to EV mode, but the control strategy is not suitable for continuous vibration process. Zhang et al 31 designed a feedforward compensation control algorithm based on harmonic injection of motor current, which uses the torque effect of harmonic current to offset the torque ripple of engine. However, it is difficult to accurately identify the real-time torque ripple of power split hybrid vehicle.…”