ABSTRACT
A mixed H2/H∞ optimal control design and its application to a missile guidance problem of homing phase are studied. The problem consists of combining the performance requirements of quadratic optimal controllers with the robustness properties of H∞ controllers. Our approach has five features. (1) The complete nonlinear kinematics of the pursuit-evasion motion are considered; neither linearization nor small angle assumption is made here. (2) The nonlinear H2/H∞ guidance law is derived analytically and expressed in a very simple form; neither iterative approximation nor complicated numerical computation is required. (3) Unlike adaptive and neural guidance laws, the implementation of the proposed robust H2/H∞ law does not need information on target acceleration. (4) Under appropriate constraints, the pair of cross-coupled Hamilton-Jacobi Partial Inequality (HJPDI) can be easily solved. (5) The derived nonlinear H2/H∞ guidance law exhibits strong robustness and excellent performance against maneuvering targets.
