Mars atmospheric entry guidance via multiple sliding surface guidance for reference trajectory tracking

To improve the accuracy of Mars landing, future missions will require robust, closed-loop guidance schemes for the entry portion of the atmospheric flight. A new nonlinear atmospheric entry guidance law for low lift landers has been developed. The Multiple Sliding Surface Guidance (MSSG) for tracking a reference trajectory is proposed. The guidance method is based on higher order sliding mode control theory adapted to the problem of entry guidance. The higher order sliding mode control has been adapted to account for the specific 2-sliding mode exhibited by the longitudinal motion of the entry vehicle, using bank angle control for following a reference trajectory. The global stability nature of the MSSG law is proven by using a Lyapunov-based approach and the performance is analyzed via a 3-DOF Monte Carlo simulation.