Research On A Compound Control Method For Quadrotor UAV

Compared with the traditional fixed-wing unmanned aerial vehicles(UAV),quad-rotor UAVs have the advantages of simple structure, vertical take-off and landing, fixed-point hovering, and can fly in a low speed, which possess the important value of military and civilian, and quickly became a hot research topic in recent years.As quad-rotor UAV is a kind of strong coupling underactuated system, the accurate dynamics model is hard to be established and the control of attitude and position has become very complex. however, the precise motion controlling is the foundation of its application in the various fields. flight controllers, only had excellent control effect, can meet the application requirements of quad-rotor unmanned aerial vehicle in various fields. This paper mainly studies the following contents:First, analyze its dynamic character and flight control principle on the basis of quad-rotor unmanned aerial vehicles experimental platform, and then analysis physical structure and the stress distribution, through theoretical derivation, using the Newton-euler equation, set up the dynamics model, and carries on the reasonable simplified, convenient the controller design.Second, base on the quad-rotor unmanned aerial vehicle dynamic model,decompose it into six subsystems, and adapt the quad-rotor control system to meet the strict feedback form, using the Backstepping method, from low to high order, in turn,construct the Lyapunov function and virtual control variables, satisfies the low order system Lyapunov stability theory, finally get the actual control.Then through the analysis of the characteristics of the quad-rotor attitude control and position control, a compound controller is designed.Attitude control loop is designed on a combination of Backstepping method and sliding mode control theory,with fast response and strong anti-jamming; Position control loop adopted adaptive Backstepping controller, makes the position control more accurate and smooth.Finally, convert the two kinds of controller into C code, and load to the experiment platform, carry on control experiment on height, attitude Angle and hovering. Compared with the controllers ahead on the control effect through the experiment, results show that the compound controller has better control effect.