Design of an observer-based anti-disturbance speed tracking controller for integrated motor-transmission systems under uncertain parameters and road slope variation

Abstract

The performance of speed tracking is crucial for electric vehicles. In this paper, the observer-based speed tracking controller is designed to improve the stability, reliability, and economy of the IMT system by obtaining unmeasurable state information using the observer. The nonlinearity of the IMT system, the uncertainty of the electric damping coefficient, and the drive shaft damping coefficient are taken into account. First, the norm-bounded uncertainty reduction method describes the system uncertainty parameters and establishes the state space in expression. Second, the system is reconstructed to deal with the nonlinear and unmeasurable states. Third, Lyapunov stability theory and linear matrix inequality (LMI) are used to design the optimal controller that has $H_{\infty }$ and LQR performance conditions to minimize the effects of sensor noise and road slope and to ensure system stability and control performance. Among them, the nonlinear mismatch term in the system is dealt with using the differential mean value theorem (DMVT). Finally, compared with other controllers, the designed controller has good tracking performance, anti-disturbance, and robustness, and the observer can estimate the state effectively.