Analysis Of Flight Dynamics Of A Quadrotor

Quad-rotor aircraft with high maneuverability,low manufacturing cost and a wide range of applications make it become a hot research topic in recent years.The model of Quad-rotor UAV is an under-actuated,coupled and nonlinear time-invariant system.In order to improve the flight stability and agility of the four-rotor aircraft,many domestic and foreign scholars have done a thorough research about this system.For this purpose,this paper focuses on the flight mechanics characteristics of the four-rotor aircraft and mainly includes the establishment of the four rotor aircraft model,the control scheme design,force analysis about different modes,related experiments and so on.Firstly,before the establishment of the mechanical model,the situation of the related coordinate system about four rotor aircraft is introduced.In the relevant coordinate system,the force of the four rotor aircraft is analyzed,and the related mechanical model of the four rotor aircraft is established.Then,the mechanical model is simplified and the relevant parameters of the mechanical model are measured by means of experiments.Secondly,based on the mechanical models of aircraft,this paper establishes the state-space expression of the four rotor aircraft,deduces the decoupling control of the state-space expression of four rotor aircraft and decomposes the multiple-input multiple-output(MIMO)system into multiple single-input single-output(SISO)system.Then this paper deduces the trajectory tracking controller of aircraft under different patterns.The related Stability,Controllability and Observability analysis are also carried out.Finally,this paper sets up a platform of four rotor aircraft and analyzes the force of the aircraft in the different mode.Then,this paper carries out the relevant flight controlling and trajectory tracking experiments by the physical platform.The results of this study have some reference value for improving the flight stability and agility of the four-rotor aircraft.