Speed control of the permanent-magnet DC motor subjected to uncertainty and disturbance

To achieve high performance in the control of electrical drives, more and more attention was paid to the uncertainty and disturbance rejection. The paper is focused on the speed control of permanent-magnet DC (PMDC) motor subjected to uncertainties and disturbances. The uncertainties and disturbances in the nonlinear system are lumped together as a total disturbance. A new control input is introduced to replace the original input and the total disturbance. A controller-design-oriented model is completed based on the new control input. Then a speed tracking controller is derived from the controller-design-oriented model by using triple-step nonlinear method. After that, an extended state observer (ESO) is designed to estimate the total disturbance by using the output error between the controller-design-oriented model and the plant. Finally, the proposed disturbance attenuation method is carefully verified by simulations. The results show that the proposed control scheme has a better control performance.