A technique for the tuning of helicopter handling qualities

The application of active control to helicopters promises to improve flight handling qualities and to expand the usable flight envelope. However, limitations of the helicopter flight mechanics models which currently provide the basis for flight control system design can have significant and degrading influence on the overall stability and performance of the resulting flight control systems. The effects of imperfectly modelled dynamics of the main rotor system on the performance of new flight control systems may necessitate the retuning of controller parameters following initial flight tests. This paper presents theory which can be used to tune controllers with respect to handling qualities requirements even in the presence of unknown dynamics.