The Conjugate Gradient Method and Its Application to Aerospace Vehicle Guidance and Control. Part II: Mars Entry Guidance and Control

摘要

The conjugate gradient method is shown to be an effective method for the guidance and control of aerospace vehicles. Mars reentry is considered as an example. As the entry angle and entry velocity are not known exactly beforehand and as there is a difference between the density of the Martian atmosphere and the assumed density profile during aerodynamic braking, and adaptive lambda matrix control element must be utilized. It is noted that the nominal trajectory on which the adaptive scheme is based does not need to be optimum in any sense. It can be any trajectory that satisfies desired boundary conditions. (Author)