Modeling and optimal control of a 3-axis motion simulator

Abstract

In this paper, a 3-axis motion simulator, as a three degreeof-freedom test stand for aircraft instrument testing and calibrating within a Hardware-In-The-Loop Environment, is studied for control analyses. A mathematical model of the simulator mechanical structure is derived and then linearized using Taylor series expansion around the instantaneous equilibrium point which is the aircraft timedependant Euler angles and their rates. Also, the aircraft, earth and atmosphere are modeled in Matlab using Aerosim blocksets. A linear quadratic regulator (LQR) control law is developed to track the attitude, angular rates and angular acceleration of the Navion aircraft in a complicated maneuver. The control law is shown to be efficient in the presence of atmospheric turbulence, and robust to unknown bounded disturbances. The accuracy and correctness of the proposed control system is verified by the simulation.