A Comparative Analysis of Different Controllers Considering Uncertainty for the Robust Position Control of DC Motor

Abstract

Growing need of industry for higher productivity is placing new demands on mechanisms connected with electrical motors. They lead to different problems in work operation due to fast dynamics and instability. The stability of the system is essential to work at desired set targets. The non- linear effects caused by a motor frequently reduce stability, which reduces the controller‘s ability to maintain speed or position at set points. Hence all the industrial process applications require robust position control of dc motor. It is more important to know how the mechanism, or in other words the load on the motor behaves. A non- linear load and also disturbance control method for dc motor is developed and implemented in the thesis. The aim of this thesis is to design a robust position control of dc motor by selecting different controllers like P, PI, PID and their tuning methods. The model of a dc motor is considered as a third order system with incorporating uncertainty. Comparison of the different kinds of tuning methods of parameter for PID controller are analyzed in the thesis. One is the controller design by Zeigler and Nichols method, second is the auto tuning of the controller in basic design mode and third is in the extended design mode. It was found that the proposed PID parameters adjustment in the basic and extended design mode is far better than the P, PI and Zeigler and Nichols method. The proposed method could be applied to the higher order system also. The dc motor is such a drive which is perhaps more often used in all industrial processes including electrical, mechanical, construction, petroleum industry, power sectors, development sites, paper industry, beverages industry, etc. so the controlled stable operation of this drive attracts the researchers always, still keeping more and more future scope in it.