Tracking control of transition window for aerospace vehicles based on robust preview control

Abstract

The transition window of aerospace vehicles (ASVs) is defined as the connection point of different flight phases or the engine mode transition point. For ASVs, one of the critical problems is the precise tracking of transition window that would enable the engine to implement the mode transition successfully. Since the engine of ASVs is independently controlled, it is required that ASV eliminates both velocity and position tracking errors within a specified time to reach the transition window accurately. In addition, the tracking control of ASVs is affected by uncertain aerodynamic parameter, initial deviation, and control constraint. Therefore, an innovative tracking control of transition window (TWTC) scheme is developed, which is composed of transient reference trajectory generation and control modules. A dynamic transient trajectory is generated to modify the tracking command to expand the initial feasible region. A piecewise robust preview control algorithm is presented for the control module design, which fuses the preview information of the reference signal, control constraint, equality constraint of ASV dynamics, and performance index function. Simulation results of a nonlinear ASV model show the effectiveness of TWTC scheme under uncertain aerodynamic parameters and initial deviations.