Comparison of nonlinear controllers for twin-lift configurations

Abstract

The stability and control problems associated with twinlift helicopter configurations are analyzed. For the two twin-lift configurations viz. twin-lift with spreader bar and twin-lift without spreader bar, a nonlinear control scheme based on feedback linearization is presented. The performance of the resulting closed-loop systems in terms of trim attitudes and required control travel for carrying out a typical twin-lift mission is evaluated through nonlinear simulation. Also, the effect of controller and sensor degradations on the overall system performance is discussed.