Research On Nonlinear Control Of Quad-rotor Stability

With the rapid development of micro controller and micro sensors,quad-rotor aircraft towards the development of Micro Electro Mechanical Systems(MEMS).At the same time,the theoretical research on the attitude detection and control of quad-rotor aircraft have been studied deeply,a large number of attitude calculation control program suitable for flight control chip operation developed.And the quad-rotor aircraft with vertical takeoff and landing(VTOL),compact structure,flexible and convenient,can be manipulated in a small space and other excellent characteristics of the hover maneuver,the aircraft has been widely used in aerial photography,disaster relief,and other aspects of the investigation.In this paper,due to the existence of nonlinear,multi-variable coupled of internal mismatch and external wind disturbances,PID control fused with nonlinear control algorithm are designed and simulated loiter experiment under the condition of no noise and impulsive noise on the software platform.Meanwhile,the control algorithm is verified on the hardware platform.Mainly work of the paper is the following two aspects.(1)According to the precise mathematical model of quad-rotor aircraft,PID fused with nonlinear disturbance observer control model is designed based on the quad-rotor simulation model on the Matlab platform.The attitude angle of the GUI monitoring interface is compiled,and the loiter experiment is carried out to verify the superiority of the control algorithm and the control parameters of the software simulation platform.(2)Software simulation for verifying the algorithm and getting the control parameters,Build the quad-rotor hardware experimental platform which contains: the MCU?3 axis gyroscope?accelerometer ?compass?altitude barometer and other components.The conventional PID fused with thenonlinear disturbance observer(NDOB)algorithm for attitude control are designed.At the same time,the computer software is used to observe the flight statement and control parameters.Hovering experiment of static equilibrium state and cruising experiment and periodic turn test of dynamic equilibrium state on the quad-rotor hardware platform under 4-5 class outdoor wind environment,PID control fused with nonlinear disturbance observer(NDOB)has strongly suppressed the external and internal mismatch disturbance of quad-rotor aircraft.