Adaptive backstepping control of separately excited DC motor with uncertainties

In this paper, a nonlinear adaptive backstepping based speed controller is designed for the field weakening area of a separately excited DC motor. The nonlinear dynamic model of the motor is firstly derived, in which the parameter uncertainties such as the inertia and load torque are considered. Then by using a linear reference model to design the transient performance and through suitable nonlinear change of coordinates, a nonlinear adaptive backstepping control algorithm is derived step by step and the stability analysis is also carried out. The mechanical speed and the back EMF tracking objectives are satisfied. Simulation results clearly show that the proposed controller is of good performance and robust to the parameter uncertainties