Dynamic modelling and parameter identification of a 3-DOF flight simulator platform

Abstract

A three-degree-of-freedom flight simulator platform with a translational and two rotational movement capabilities is studied. Based on the Lagrange method the dynamic model is established and then simplified by eliminating the sub-diagonal elements of the matrixes. A washout algorithm is employed to qualify the platform for flight simulation in limited space. In order to improve the modeling and experimental accuracies further when some dynamic parameters of an actual platform are unknown, the stepwise identification method is proposed to solve this problem. By dividing the driving torque into the load torque, reducer driving torque, screw driving toque and integrated friction torque, and main dynamic parameters are identified by applying proper trajectories and estimated by the weighed least square method. The procedures of identification are verified through comparing the driving forces from the identified model and those of servo motor encoders.