Design and implementation of a flight control system for an unmanned rotorcraft using RPT control approach

We utilize a so-called robust and perfect tracking (RPT) control technique in this paper to design an outer-loop control law to control the position of an unmanned rotorcraft system, which is capable of achieving much better performance for situations when complicated maneuvers are required. The RPT control technique is to design a controller such that the resulting closed-loop system is asymptotically stable and the controlled output almost perfectly tracks a given reference signal in the presence of any initial conditions and external disturbances. It makes use of all possible information including the system measurement output and the command reference signal together with all its derivatives, if available, for control. The result has been successfully verified and demonstrated in both simulation and actual flight tests.