Adaptable method of managing jets and aerosurfaces for aerospace vehicle control

Abstract

An actuator selection procedure is presented that uses linear programming to optimally specify bounded aerosurface deflections and jet firings in response to differential torque and/or force commands. This method creates a highly adaptable interface to vehicle control logic by automatically providing intrinsic actuator decoupling, dynamic response to actuator reconfiguration, dynamic upper bound and objective specification, and the capability of coordinating hybrid operation with dissimilar actuators. The objective function minimized by the linear programming algorithm is adapted to realize several goals, i.e., discourage large aerosurface deflections, encourage the use of certain aerosurfaces (speedbrake, body flap) as a function of vehicle state, minimize drag, contribute to translational control, and adjust the balance between jet firings and aerosurface activity during hybrid operation. A vehicle model adapted from Space Shuttle aerodynamic data is employed in simulation examples that drive the actuator selection with a six-axis vehicle controller tracking a scheduled re-entry trajectory.