Robust Approach of Optimal Control for DC Motor in Robotic Arm System using Matlab Environment

Modern automation robotics have replaced many human workers in industrial factories around the globe. The robotic arms are used for several manufacturing applications, and their responses required optimal control. In this paper, a robust approach of optimal position control for a DC motor in the robotic arm system is proposed. The general component of the automation system is first introduced. The mathematical model and the corresponding transfer functions of a DC motor in the robotic arm system are presented.  The investigations of using DC motor in the robotic arm system without controller lead to poor system performance. Therefore, the analysis and design of a Proportional plus Integration plus Divertive (PID) controller is illustrated. The tuning procedure of the PID controller gains is discussed to achieve the best responses of the DC motor. It is found that with the PID controller, the system performance is enhanced, especially in terms of steady-state error but does not provide the required optimal control.  The required approach of Ackerman's formula optimal controller based on state-space feedback is investigated. A GUI using the Matlab environment is created to obtain the DC motor's responses without using a controller and with controllers. It is found that the proposed approach of the optimal controller has more robustness and enhances the overall performance of the existing PID controller in the form of reducing settling times (from 2.23 second to 0.776 seconds), minimizing percent overshoot (from 27.7 % to 1.31 %) and zero value of steady-state error