Design of sliding mode control with disturbance observers for inertial platform

In the flight process, the disturbances such as vibrations and frictions affect the stability accuracy of the servo loop of the inertial platform. Besides, the model uncertainties exist due to the couplings of the three subsystem of the inertial platform. This paper presents a sliding mode controller based on a proportional integral (PI) disturbance observer. The state variables and disturbing torque are estimated accurately by the PI observer. Additionally, an integral sliding mode controller is designed. The vibration and stability error are reduced by employing the integral items of the states in designing the sliding mode surface. The simulation results show that the proposed methods can improve the control precision of the servo loop of the platform.