m Abdo - Department of Electrical Engineering, Malek-Ashtar University of Technology, Tehran, Iran
a.r Toloei - Department of Aerospace, Shahid Beheshti University , Tehran, Iran
a.r Vali - Department of Aerospace, Shahid Beheshti University , Tehran, Iran
m.r Arvan - Department of Aerospace, Shahid Beheshti University , Tehran, Iran

The gimbal stabilization mechanism is used to provide the stability to an object mounted on the gimbal by isolating it from the base angular motion and vibration. The purpose of this paper is to present amodel of control servo system for one axis gimbal mechanism using a cascade PID controller. Thegimbal torque relationships are derived by taking into consideration the base angular motion. The conventional PID controller and three cascade controller structures are investigated. The servo control loop is built and modelled in MATLAB/Simulink using these controllers. The simulation results arecompared and the servo system performance is analysed for each controller in terms of performance criteria. The comparison results prove that a further improved system performance is achieved using IPD controller as compared to the system performance obtained when the other controllers are utilized.The paper’s value lies in designing the servo control system using a modified controller composed of two parallel I-PD controllers related with a switch depending on the base angular rate as a threshold. The results show that the modified system satisfies the desired servo system requirements

Gimbal System,Rtae Gyro,Line of Sight,Stabilization Loop,Servo System,DC Motor