CONTROL OF MARS GUIDED ENTRY (PART II): ROBUST NONLINEAR DYNAMICS INVERSION

This paper addresses the 6 degrees-of-freedom control of a Mars Lander Module during its aerodynamic entry phase. It focuses on Robust Nonlinear Dynamics Inversion (RDI) technique. On one hand, RDI is shown to be efficient for translation controller synthesis. On the other hand, this technique is shown to be inappropriate for attitude control except for the gyroscopic torque cancellation which could be coupled with a robust static controller. Monte-Carlo simulations are performed to demonstrate the robust performance of the 6 DOF control software. The nonlinear simulator includes a realistic model of the atmosphere (European Mars Climate Database) and Mars gravity (J2).