Normal Acceleration Reduce Guidance and Control for Sub-orbit Vehicle Re-entry

Abstract

In this paper, a new angle-of-attack(AOA) guidance law and controller with multi-control surface and reaction control system (RCS) are designed to reduce normal acceleration in suborbital re-entry phase. First, the six-degree-of-freedom (6 DOF) nonlinear dynamic model of sub-orbital vehicles established, and the overload characteristics is analyzed under traditional AOA guidance law. Second, an AOA guidance law added height element is proposed to reduce the Normal accelerate peak value during re-entry. Furthermore, an Inverse-PIDA control law and composite control strategy are designed to control multi-aerodynamic surface and RCS. Finally the proposed approach is applied in a sub-orbital vehicle re-entry flight, validation simulation are conducted by using the proposed guidance law and controller with the 6 DOF nonlinear dynamic model , Monte-Carlo statistical analysis shows it can get well control performance with ±20% aerodynamic elements uncertainty and random wind.