Nonlinear adaptive controller design for velocity control of a DC motor driven by a DC-DC buck converter using backstepping approach

In this paper, a nonlinear adaptive controller is proposed to control the velocity of DC motors driven by DC-DC buck converters. The proposed controller is designed recursively based on the Lyapunov theory by considering the load torque of the DC motor is unknown. This unknown parameter is estimated through the adaptation law and the stability of the whole system is ensured based on the control Lyapunov function (CLF). Another main feature of the proposed control scheme is that it overcomes the over-parameterization problems of unknown parameter which generally emerges in some conformist adaptive methods. At last, the usefulness of the proposed control scheme is verified through the simulation results and performances of the designed controller are compared with an existing proportional-integral (PI) controller. Simulations results demonstrate the superiority of the proposed control scheme over an existing PI controller in term of settling time.