A class of robust guidance laws for reentry guidance

The use of a dynamical model for a reentry vehicle employing a trajectory variable as the independent variable of evolution yields a guidance law which is insensitive to some of the exogenous disturbances commonly encountered by the vehicle. When there are several candidate variables upon which to base the guidance law, it is difficult to compare the associated performance characteristics. Previous work has had to restrict itself to local measures of system response because of the analytical intractability of the comparison indices. This paper presents the results of a study of alternative guidance laws using a nonlinear vehicle model of reasonable size. Some of the basic properties of advantageous reentry guidance laws are isolated.