Nonlinear Optimal Control Techniques Applied to a Launch Vehicle Autopilot

Abstract

This paper presents an application of the nonlinear optimal control techniques to the design of launch vehicle autopilots. The optimal control is given by the solution to the Hamilton-Jacobi-Bellman (HJB) equation, which in this case cannot be solved explicity. A method based upon Successive Galerkin Approximation (SGA), is used to obtain an approximate optimal solution. Simulation results involving three degrees of freedom (3DOF) model of a launch vehicle during atmospheric flight are reported to demonstrate the performance of the considered autopilot. Alternative results are also presented for classical and linear optimal approaches.