Design of variable-structure attitude control system for RLV (reusable launch vehicle)

In the full paper, we explain our design in detail; in this abstract, we just add some pertinent remarks to listing the three topics of explanation; (1) mathematical model, (2) the design of attitude control law, and (3) control allocation; under topic 1, eqs.(1), (3), (4) and (5) are taken from the open literature but eq.(2), though originally also taken from the open literature, has been suitably modified for our design; the subtopics of topic 2 are longitudinal control (subtopic 2.1) and lateral/directional control (subtopic 2.2); under subtopic 2.1, eqs.(6), (7) and (8) are all taken from the open literature except that eqs.(7) and (8) have been suitably modified; under subtopic 2.2, eqs.(9) and (12) are derived by us; under topic 3, we explain how to make the allocation of control torque to aero-surface and reaction control system (RCS) reasonable with an on-line control algorithm based on eqs.(13) through (16); also under topic 3, eqs.(14) and (15) are derived by us and eqs.(13) and (16) are taken from the open literature but suitably modified. Simulation results, given in Figs.1, 2 and 3 in the full paper, show preliminarily that the variable-structure attitude control system for RLV designed by us ensures that its tracking performance is accurate, robust and decoupled. The error of attitude angle is kept within 1° and overshoot is kept under 5%.