Due to the coupled motion between the rotor unmanned aerial vehicle(UAV)and the manipulator,the underactuation characteristics of the system itself,and the influence of external uncertainties,the stability of the roto...Due to the coupled motion between the rotor unmanned aerial vehicle(UAV)and the manipulator,the underactuation characteristics of the system itself,and the influence of external uncertainties,the stability of the rotor UAV’s manipulator control system is difficult to control.Based on the dynamic model of the rotor UAV,the stability of the whole UAV manipulator control system is improved by using the piecewise cost function,the compression factor particle swarm optimization(PSO)algorithm and the sliding mode PID to establish the sliding mode PID control stability method based on the PSO.Compared with the sliding mode PID control method,this method solves the serious buffeting problem in the sliding mode control,reduces the influence of the external disturbance and realizes the attitude stabilization control of the UAV manipulator quickly and accurately,thus shortens the system adjustment time and improves the anti-interference ability.展开更多
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
Current climate forecasting has advanced to the stage of investigating mesoscale air-sea interactions. Recent studies have identified significant structural differences between the cores and edges of mesoscale eddies;...Current climate forecasting has advanced to the stage of investigating mesoscale air-sea interactions. Recent studies have identified significant structural differences between the cores and edges of mesoscale eddies;however, the effects of these structural variations on air-sea fluxes and the Marine Atmospheric Boundary Layer(MABL) remain underexplored. Traditional observations often fail to capture the detailed structures of eddies, necessitating enhanced observations at high spatiotemporal resolution for mesoscale eddies. To address this, efforts have been made to develop multi-agent platforms and expendable air-sea interface observation technologies. A task-oriented observation scheme was developed to monitor the spatial characteristics of mesoscale eddies. The South China Sea(SCS) is rich in mesoscale eddies with rapid motion changes, requiring enhanced observations of the air-sea interface using multi-agent mobile networking. An anticyclonic eddy was observed in the eastern region of the Xisha Islands in the SCS, and we examined variations in air-sea fluxes across different regions within the eddy.展开更多
基金This research is supported by the National Natural Science Foundation of China(51875293,51575283,61605083,51605232)Key points for marine environmental security(2018YFC1405700).
文摘Due to the coupled motion between the rotor unmanned aerial vehicle(UAV)and the manipulator,the underactuation characteristics of the system itself,and the influence of external uncertainties,the stability of the rotor UAV’s manipulator control system is difficult to control.Based on the dynamic model of the rotor UAV,the stability of the whole UAV manipulator control system is improved by using the piecewise cost function,the compression factor particle swarm optimization(PSO)algorithm and the sliding mode PID to establish the sliding mode PID control stability method based on the PSO.Compared with the sliding mode PID control method,this method solves the serious buffeting problem in the sliding mode control,reduces the influence of the external disturbance and realizes the attitude stabilization control of the UAV manipulator quickly and accurately,thus shortens the system adjustment time and improves the anti-interference ability.
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.
基金supported by the National Key R&D Program of China (Grant No.2018YFC1405700)the National Natural Science Foundation of China (Grant No.42227901)。
文摘Current climate forecasting has advanced to the stage of investigating mesoscale air-sea interactions. Recent studies have identified significant structural differences between the cores and edges of mesoscale eddies;however, the effects of these structural variations on air-sea fluxes and the Marine Atmospheric Boundary Layer(MABL) remain underexplored. Traditional observations often fail to capture the detailed structures of eddies, necessitating enhanced observations at high spatiotemporal resolution for mesoscale eddies. To address this, efforts have been made to develop multi-agent platforms and expendable air-sea interface observation technologies. A task-oriented observation scheme was developed to monitor the spatial characteristics of mesoscale eddies. The South China Sea(SCS) is rich in mesoscale eddies with rapid motion changes, requiring enhanced observations of the air-sea interface using multi-agent mobile networking. An anticyclonic eddy was observed in the eastern region of the Xisha Islands in the SCS, and we examined variations in air-sea fluxes across different regions within the eddy.