Robust flight control system design for an indoor miniature coaxial helicopter

A complete flight control scheme with detailed design methodology is proposed for an indoor miniature coaxial helicopter with fixed collective pitch. To avoid system complexity and the problem of minimum phase control, the helicopter dynamic model is decomposed into two cascaded subsystems: an inner one for attitude and heading control and the outer one for trajectory control. H-infinity control technique and robust and perfect tracking method are used to respectively design the inner- and outer-loop controllers. By using the so-called asymptotic time-scale and eigenstructure assignment approach, the design process becomes very systematic and effective. The performance of the autonomous flight control system has been successfully validated in actual flight tests.