Control of DC motors using sliding mode

DC motors have been extensively used in many industrial applications for their accurate, simple and continuous control characteristics. This paper addresses the controlling of the speed of DC motor which remains among the vital issues. It presents sliding mode control, integral sliding mode control and dynamic sliding mode control methods to control the speed of DC motors. Also the merits and demerits of each approach are discussed. Sliding mode control (SMC) is robust to the matched uncertainties and the desired performance/speed is attained. But the main drawback of SMC is chattering, resulting from discontinuous controllers, various techniques are presented to minimize chattering. The performance of the dynamic system with integral and first order dynamic SMC is compared with response of the system with SMC controller. The results show that the integral and specifically dynamic SMC are more robust against matched uncertainties, the desired speed is perfectly tracked and chattering reduction is achieved.