Adaptive controller design for speed control of DC motors driven by a DC-DC buck converter

A nonlinear adaptive controller for controlling the desired velocity of DC motors driven by DC-DC buck converters is proposed in this paper. The proposed controller is designed recursively based on the control Lyapunov function (CLF) to assure the desired control performance under varying the load torque of the DC motor as well as by considering the system parameters as unknown. These unknown parameters along with unknown load torque are estimated using the adaptation laws and incorporated in the control law to enhance the robustness of the proposed controller. To prove the speculative stability of the whole system, the CLFs are formulated at different stages during the design process of the controller. Another key attribute of the proposed adaptive control scheme is that it can overwhelm the over-parameterization problems of unknown parameters which generally come out in some conformist adaptive backstepping methods. Finally, the helpfulness of the proposed control scheme is demonstrated through the computer simulation results and performance of the designed controller is also compared with an existing adaptive backstepping controller.