Modeling and Integral Sliding Mode Control of a Roll-yaw Seeker by Removing the Singularity Condition

This paper aims to model and sliding mode control of a roll-yaw seeker. In the roll-yaw seeker, a singularity occurs when the seeker is directed precisely to a target, and the seeker will lose the target. Thus, the Controller design should contain a tracking strategy to deal with the singularity. In this paper, Newton-Euler's method is applied to the dynamic model of a roll-yaw seeker's roll and yaw gimbals. The dynamics of the roll-yaw seeker are highly nonlinear. Also, unmodeled uncertainties and perturbations reduce the model's reliability. A two-input, two-output integral sliding mode controller is designed to control the nonlinear dynamics of the seeker and deal with uncertainties. The numerical simulation results show that all three stabilization, tracking, and guidance loops in both roll and yaw channels have acceptable performance. Also, it is shown that the controller has good robustness.