Feedback Stabilization of a Two-Axis Gimbal System Via Conservative Stability Analysis

This paper discusses the stabilization problem of a yaw-pitch gimbaled seeker system under the condition that system uncertainties and actuator saturation nonlinearity cannot be ignored. Based on gimbal dynamics, a dynamics model is formulated for the two-axis gimbaled seeker, and the perturbation effect of platform angular motion to system configuration is studied. The variation intervals of the perturbed parameters are furthermore estimated, and the uncertainty description of the gimbaled system is obtained. Two stable regions are conservatively estimated by judging the stability of interval matrix and solving the linear matrix inequalities (LMIs), respectively, and then the condition under which the two-axis gimbaled seeker can be stabilized and the method via which the system can be optimally stabilized are presented. The analysis method presented in this paper can provide guidelines for the optimal design of stable control loop for the two-axis gimbaled seeker.