Integral barrier Lyapunov function-based three-dimensional low-order integrated guidance and control design with seeker's field-of-view constraint

Abstract

As the strap-down seeker with its detector is fixed onto the body of the flight vehicle, its measurement is coupled with the information of the attitude motion of the vehicle's body, which results that the inertial line-of-sight (LOS) angular rate used in the traditional guidance laws cannot be measured. Besides, the process that the vehicle adjusts its attitude to realize the instantaneous overload command may cause the target to be outside the field-of-view (FOV) of the seeker. To deal with the FOV constraint and the lack of the inertial LOS angular rate, the novel body-LOS coordinate system based relative motion equations are derived, in which the derivative of attitude angular rates appears. Combined with the dynamics of attitude angular rates, the original low-order integrated guidance and control (IGC) design model with FOV constraint and the roll channel IGC design model are established. Furthermore, an integral Barrier Lyapunov function (IBLF) based three-dimensional low-order IGC scheme with the FOV constraint is proposed in this paper. Meanwhile, the adaptive algorithms are employed to estimate the square of the upper bound of the disturbance, which would be compensated in the IGC scheme to improve the robustness of the control system. Both system order and tuning parameters of the proposed low-order IGC algorithm dramatically decrease, and the design procedure is significantly simplified. With the aid of Lyapunov stability analysis, states of the IGC closed-loop system are proved to be uniformly ultimate bounded. Finally, extensive numerical simulations are carried out to validate the effectiveness and robustness of the newly proposed IGC scheme.