Integrated guidance and control of agile missiles using the Finite-SDRE approach

Abstract

A skid-to-turn cruciform tail-controlled missile, which is roll-stabilized, is considered to intercept a head-on weaving target. The aerodynamic nonlinearity of the missile is considered. Three types of guidance and control design concepts are explored: a traditional separated approach, a integrated single-loop design and a integrated two-loop one. In the separated case, the outer guidance loop design is treated as a solution to the nonlinear finite-horizon control problem. The inner autopilot loop is stated as a solution to the nonlinear infinite-horizon control problem. The integrated design considers the coupling between the control and guidance dynamics. In the integrated single-loop case, the guidance and autopilot design is formulated into a single-loop nonlinear finite-horizon optimal control framework. In the integrated two-loop case, the inner loop autopilot loop is designed independently from the outer guidance one, but all the states are feedback to the guidance loop. A finite-horizon suboptimal control method, called the Finite-horizon State-Dependent Riccati Equation (Finite-SDRE) technique, is employed to obtain the closed-loop solutions of the aforementioned problems. Finally, the performance of the three guidance and control laws is investigated via numerical simulations. And results show the superiority of the integrated design.