A study on the control method of a ship borne launcher using a system identification method

A ship borne launcher normally has a two-axes yaw-pitch gimbal configuration that can designate the target regardless of external disturbances, such as waves or wind. This kind of ship borne launcher is also called an inertially stabilized platform. Inertial stabilization is important in many aerospace and military applications, for example carrying out optical sensor functions, image processing, or target tracking. Various studies accordingly have been performed to achieve desired inertial stabilization performance. A ship borne launcher is a highly nonlinear system that cannot easily be expressed in an analytical form when considering nonlinearity elements. In particular, it is difficult to decouple the dynamic model of a ship borne launcher. In this case, an experimentally obtained dynamic model is more accurate than the analytically derived dynamic model. This paper proposes a method to simplify this nonlinear system through a system identification method, specifically, Eigensystem Realization Algorithm (ERA).