Control And Simulation Of Single Rotor Unmanned Helicopter With Ducted-Fan

The unmanned helicopter(UH)is a kind of special and indispensable unmanned aerial vehicle in photography,surveillance and reconnaissance applications because of the unique VTOL and hover flight characteristics,UH flight control and simulation technology is a hot research topic.In this paper,we take the single rotor UH with ducted fan as the object,focus on the mathematical modeling,UH flight control and simulation.The main pneumatic components of the UH are rotor,fan and duct body.The model should be able to reflect the dynamic and kinematic characteristics of main components and the whole machine.Six freedom degrees dynamic equations and the kinematic equations are established based on assumptions,the fitting model is derived by blowing test data and data fitting method.In order to facilitate flight control research,the nonlinear mathematical model of a small disturbance linearization is processing,and take hovering equilibrium state as example,the characteristic root distribution,zero input response and zero state response curves are analyzed to obtain the stability of the UH and the coupling characteristics.Based on the analysis of control characteristics and control strategy,this paper use constant decoupling method to realize decoupling,use classical control theory to design control law,and discusses the path planning.In order to validate the model and control laws,the vertical flight and scheduled routes of autonomous flight simulation test subjects are implemented in digital and semi-physical simulation tests,meanwhile the confidence of simulation system is analyzed by using analytic hierarchy process.UH is a typical multi input and output system,and its characteristics and disturbance change greatly.Considering the theory of SMC has a good control effect on "uncertainty" system,and improve the system stability and dynamic performance,this paper discusses the application of SMC theory in UH flight control,expounds the causes and countermeasures of the chattering and designs a controller,in order to further suppress chattering,integrates adaptive control and SMC to improve the controller,using lyapunov stability theory to analyze stability of sliding mode controller,finally prove the superiority of the sliding mode control theory through the simulation test and the results.