DC motors are often used in a variety of industrial applications. These motors are easily controllable and their position can be adjusted with low cost. However, one of the problems that hampers the motor control, despite the proper initial design, is the change of control system parameters. Indeed, each control system should be robust for a pre-defined range of internal and external changes. In this paper, an attempt is made to discuss the mathematical model of the motor and the associated nonlinear factors. Afterwards, a robust control scheme, which considers torque as an external perturbation signal and nonlinear dynamics in the motor, is proposed to control position of DC. To this end, H2 and H∞ methods are combined.
