This paper is a technical note about the theoretical evaluation of the bandwidth of multirotor helicopters. Starting from a mathematical linear model of the dynamics of a multirotor aircraft, the transfer functions of the state variables that deeply affect the stability characteristics of the aircraft are obtained. From these transfer functions, the frequency response analysis of the system is effected. After this analysis, the bandwidth of the system is defined. This result is immediately utilized for the design of discrete PID controllers for hovering flight stabilization. Numeric simulations are shown to demonstrate that the knowledge of the bandwidth is a valid aid in the design of flight control systems of these machines.
This technical note describes a simplified study of the flare maneuver of a helicopter at the end of an autorotation descent. Energy methods and momentum theory were utilized for the analysis of the parameters involved in the flare maneuver. A simulation was run on the basis of the data available for a commercial helicopter. The results are discussed, and a series of parameters are defined for the performance analysis of the flare maneuver.
In this paper the natural modes of motion of a multi-rotor helicopter in hovering flight are discussed. The linear equations of motion of the aircraft are presented. After an eigenvalues analysis of the state matrix the dynamic modes are defined. The connections between the stability derivatives and the dynamic stability of the aircraft are pointed out. Thus, the effects of the aircraft features on the unforced motion characteristics are evaluated. These results are useful for either the design of new vehicles or the analysis of an existing one, as witnessed by a numeric example.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.