An Improved PID Control Scheme for DC Servo Motor using Salp Swarm Algorithm

The DC Servo Motor (DCSM) is widely implemented in several applications like conveyor belts, solar tracking system, robotics, and camera auto focus. DCSM is efficient and small but critical for use in the applications that require precise position control. This paper proposes an improved PID control scheme for controlling the position of DCSM. In this paper, the DCSM with PID controller model is achieved through MATLAB/Simulink software. Although the PID controller is simple for implementation, its parameter tuning problem will degrade the performance. This paper contributes applying the Salp Swarm Algorithm (SSA) for tuning the PID controller using a proposed Weighted Goal Fitness Function (WGFF). The PID optimized using SSA via the WGFF (the proposed controller i.e. SSA-PID-WGFF) is compared with conventional PID controller and PID controller tuned by the Integrated-Absolute Error (IAE), Integrated Time-Weighted Absolute Error (ITAE), Integrated-Squared Error (ISE), and Integrated Time-Weighted Squared Error (ITSE) fitness functions (error criteria) used in the literature. For validation, the proposed controller is tested under variable position and load disturbance. The verification results proved that the proposed control scheme provides more proficient in improving the dynamic responses of the DCSM than the other controllers used in the literature. Verification results demonstrated that the DCSM with the SSA-PID-WGFF controller has a noticeable ability to maintain the robustness and stability under load disturbance and variable position command. Finally, verification results indicate better responses for DCSM performance (position, error in position, current, and devolved torque).