In the transition mode of quad tilt wing-unmanned aerial vehicle(QTW-UAV),the system stability of UAV will change with the tilt angle changes,which will cause serious head drop down.Meanwhile,with the complex air flow...In the transition mode of quad tilt wing-unmanned aerial vehicle(QTW-UAV),the system stability of UAV will change with the tilt angle changes,which will cause serious head drop down.Meanwhile,with the complex air flow and other disturbances,the system is prone to side bias,frying,stall and other kinetic stability problems,hence the system stability analysis has become an urgent problem to be solved.To solve the stability problem,we need the quantitative criteria of system stability and effective tool of stability analysis,and can improve the stability of the motion control by optimizing the structural parameters of the aircraft.Therefore,based on the design of the mechanical structure,the quantitative relationship between the structure parameters of the aerial vehicle and kinetic stability of the system transition mode is established by the Lyapunov exponent method.In this paper,the dynamic modeling of the position and attitude angle is carried out and the stability of the system is analyzed by Lyapunov exponent,the results show that changing the mechanical structure of the system can improve the flight stability for the system transition mode and lay a theoretical foundation for the system stability analysis.Compared with the Lyapunov direct method,this method can be construct easily,has a simple calculation process and so on.We improve the flight stability by optimizing the structure and the experiment confirms that expanding area can enhance flight stability within limits.展开更多
Partial Lyapunov stability and partial Lipschitz stability in Flows are introduced. It is proved that a flow on a compact metric space is Lyapunov stable if and only if it is partial Lyapunov stable with respect to a ...Partial Lyapunov stability and partial Lipschitz stability in Flows are introduced. It is proved that a flow on a compact metric space is Lyapunov stable if and only if it is partial Lyapunov stable with respect to a c -dense subset of the real numbers. Also it is proved that a C r(r≥ 1) flow on a compact, connected Riemannian manifold is Lipschitz stable if and only if it is partial Lipschitz stable with respect to a c -dense subset of the real numbers. Moreover, the dynamical properties of transitive Lyapunov stable flows are studied.展开更多
基金This research is supported financially by Natural Science Foundation of China(Grant No.51575283,No.51405243).
文摘In the transition mode of quad tilt wing-unmanned aerial vehicle(QTW-UAV),the system stability of UAV will change with the tilt angle changes,which will cause serious head drop down.Meanwhile,with the complex air flow and other disturbances,the system is prone to side bias,frying,stall and other kinetic stability problems,hence the system stability analysis has become an urgent problem to be solved.To solve the stability problem,we need the quantitative criteria of system stability and effective tool of stability analysis,and can improve the stability of the motion control by optimizing the structural parameters of the aircraft.Therefore,based on the design of the mechanical structure,the quantitative relationship between the structure parameters of the aerial vehicle and kinetic stability of the system transition mode is established by the Lyapunov exponent method.In this paper,the dynamic modeling of the position and attitude angle is carried out and the stability of the system is analyzed by Lyapunov exponent,the results show that changing the mechanical structure of the system can improve the flight stability for the system transition mode and lay a theoretical foundation for the system stability analysis.Compared with the Lyapunov direct method,this method can be construct easily,has a simple calculation process and so on.We improve the flight stability by optimizing the structure and the experiment confirms that expanding area can enhance flight stability within limits.
文摘Partial Lyapunov stability and partial Lipschitz stability in Flows are introduced. It is proved that a flow on a compact metric space is Lyapunov stable if and only if it is partial Lyapunov stable with respect to a c -dense subset of the real numbers. Also it is proved that a C r(r≥ 1) flow on a compact, connected Riemannian manifold is Lipschitz stable if and only if it is partial Lipschitz stable with respect to a c -dense subset of the real numbers. Moreover, the dynamical properties of transitive Lyapunov stable flows are studied.
