On the regulation of a helicopter system: A trajectory planning approach for the Liouvillian model

A feedback regulation scheme is presented which allows for a wide range of displacement maneuvers on a simplified longitudinal model of a helicopter system which is underactuated and nondifferentially flat. The system, nevertheless, is shown to be of the "Liouvillian" type. An off-line, open loop, trajectory planning procedure is proposed, based on the solution of differential equations for the desired attitude angle reference signal, which precisely results in the desired nominal horizontal displacement trajectory. The performance of a proposed feedback controller, which exploits the fact that the linearized system has its coefficients on a Hardy filed, is evaluated through digital computer simulations including unmodelled mid course wind gusts and initial setting errors.