Experimental analysis and simulation of the dynamix response of a propeller pitch change actuator

Abstract

This paper focuses specifically on the control of the propeller pitch change mechanisms and their associated dynamics. The subject of this article is restricted to the mechanisms using a hydraulic single acting actuator. They function asymmetrically and are subject to important varying external loads under the full flight envelope. This phenomenon has an impact on their dynamic response. The question of the dynamics of these systems is rarely dealt with because, usually for aircraft applications, there is no real requirement for propeller pitch dynamic control. But, in the case of some applications, such as the Eurocopter X3, this dynamic control aspect and the safety aspect of the propeller pitch change mechanism are particularly important, because this mechanism is fully involved in aircraft safety, control and handling qualities. Firstly, this paper gives an explanation of the phenomena applied to the propeller pitch change mechanism and their contributions to its dynamic response. Then, a model of the dynamic response is proposed. Finally, an experimental identification of the pitch change mechanism dynamics concludes this article.