Time-varying spectrum based active disturbance rejection control for hypersonic reentry vehicle

This paper proposes a robust attitude control strategy for hypersonic reentry vehicles which combines novel time-varying spectrum based active disturbance rejection control techniques with a basic stabilizing controller. These techniques include time-varying tracking differentiator (TTD) and time-varying extended state observer (TESO). By adopting time-varying bandwidth, TTD can adaptively arrange transient processes for either abrupt or smooth reference commands. Also by designing time-varying bandwidth logic, TESO can not only estimate total disturbance well, but also suppress peaking phenomenon resulting from initial reentry condition dispersion. Several simulations are conducted which demonstrate that the proposed control strategy exhibits both good attitude tracking ability and great design flexibility.