Performance Assessment of a Model-based DC Motor Scheme

Abstract

The separately-excited DC motor is a high-performance variable speed drive with industrial applications such as in robotics, actuation, control and guided manipulation due to its precision, simplicity, continuous control feature and wide speed range. There is therefore, the need to regulate and drive the motor at desired speed in the presence of uncertainties and motor parameter variations. However, there is not a single optimal controller for the machine. Hence, one major control objective is to find the perfect trade-off between performance and robustness. The conventional Proportional-Integral-Derivative (PID) controller is not the optimal control strategy to achieve this objective because of its oscillatory response, inability to cope with changing operating conditions and sensitivity to motor parameter variations. Hence, this paper proposes a performance review of the Internal Model Control (IMC) feedback scheme in order to find the optimal controller setting that will ensure tight control which is high performance subject to acceptable robustness. This optimal controller setting will ensure excellent reference speed tracking, fast and non-oscillatory response subject to acceptable robustness to motor parameter variations. Computer simulations are also presented to show the practicability of the study.