Parameter estimation and fuzzy controller design for a two-axis gimbal

Abstract

This work presents a Gauss-Newton gradient-based method for identification of the unknown parameters of the dynamic equations of a two-axis gimbal system and design of a suitable fuzzy controller for it. Among the most important uncertain parameters considered in the dynamic equations of a two-axis gimbal, the components of the inertia matrix, the coriolis matrix, the friction matrix and the torque caused by the distance from the center of gravity to the axis of rotation can be named. The input data is measured in response to a known stimulation by the sensors and used as the reference data for the identification process. Regarding the severe sensitivity of inverse problems to measurement errors, using a proper smoothing technique, this undesirable effect is reduced. After identification of the missing parameters, a Mamdani fuzzy controller is used for stabilizing the line of sight of the gimbal. Fuzzy rules are determined according to the dynamic equations and based on the study of the effect of torque changes in the tracking path of the object. Simulation results are given to demonstrate the effectiveness and performance of the proposed fuzzy controller.