Combined Fuzzy-PID Controller of an Inertial Stabilized Platform

Abstract

An Inertially Stabilized Platform (ISP) is used when certain sensors are meant to be stable around a required orientation regardless of any movements of the carrier platform. ISPs are essential for vision-guided flying vehicles to stabilize the equipped seeker attached to the guided vehicle body for efficient target tracking and guidance. This work aims to design a suitable and robust controller for an ISP that can mitigate the disturbances and noise expected when attached to a guided vehicle seeker system. The ISP system is modeled, designed, and implemented. To overcome system uncertainties, external disturbances, and coupling, an efficient controller is to be designed to meet stability and performance requirements. In this research, a decoupled dynamic modelling of a two-axis ISP while accounting for system uncertainties is introduced. In addition to that, a combined fuzzy-PID controller is designed. To evaluate the proposed system's performance, a series of experiments based on two axes and transformations between two frames are carried out. The proposed controllers are compared to traditional PID controllers. The simulation and laboratory tests show the high performance achieved by the proposed combined fuzzy-PID controller for the designed ISP, where better robustness, transient response, and steady-state error are obtained when compared to the conventional controllers.