Design of a new blended PID/H∞ robust and minimum-energy flight control system

We discuss the robust control problem that requires the simultaneous satisfaction of both quadratic stability and minimum-energy index; then we propose the design of a new blended PID/H∞ robust and minimum-energy flight control system. In the full paper, we explain our discussion and proposal in some detail. In this abstract, we just add some pertinent remarks to the three topics of explanation. The first topic is: the robust control problem that requires the simultaneous satisfaction of both quadratic stability and minimum-energy index for a system with parameter uncertainties. In the first topic, we give a detailed mathematical discussion; essentially it does two things; (1) the consideration of external disturbance and parameter uncertainties both in system matrix and control matrix; (2) by some transformations, the solution is converted to a standard H∞ control problem and the feedback gain matrix can be easily obtained by solving a Riccati equation. The second topic is: the design of a new blended PID/H∞ robust and minimum-energy flight control system. In the second topic, we present a new robust flight control structure that includes two loops. The inner loop controller is designed to reject external disturbance and system parameter uncertainties based on our approach. The traditional PID controller is used in the outer loop (Fig.1 in the full paper). The third topic is: simulation example. We selected the flight operation states of a UAV (unmanned aerial vehicle) in the simulation for performance comparison. The results (Figs 2 through 5 in the full paper) show preliminarily that the new flight control system has lower control effort, smaller overshoots and shorter setting-time compared with the traditional one.