Design And Control Algorithm For Moored Shipborne Unmanned Aerial Vehicle With Large Load

Unmanned aerial vehicles(UAV)have been used in various fields for nearly one hundred years.In particular,under the concept of "modernization,information and integration" of naval equipment,the carrier-borne UAV system has become a kind of carrier-borne combat system developed by navies in worldwide.Carrier-based unmanned aerial vehicle system is a high intelligent weapon equipment on naval vessels.It can undertake multidisciplinary tasks such as alert,guidance,bait and other special operational tasks.It will be the backbone in the future war,leading the great variation of future combat style.Ordinary ships with limitations on space cannot provide a runway for fixed wing aircrafts taking-off and landing,so the multi-rotor unmanned aerial vehicle which has the function of vertical take-off and landing becomes an important equipment on naval vessels.Based on high reconnaissance ability,large data processing,long-endurance carrier-based unmanned aerial vehicle is an urgent need.With the large payload-based carrier-borne UAV as a research object,this thesis studies the controller design and control algorithm of tethered type ship-based unmanned aerial vehicles.First the problem of wind resistance is put forwarded as a key problem to be solved in the design of controller of tethered UAV.In order to accurately simulate the influence of actual wind field on the tethered type ship-based unmanned aerial vehicle,the tethered type ship-based UAV mathematical model,the mooring line model and the corresponding atmospheric wind field model are established,and simulation research are made based on the models.Because of the uncertainties of special wind field of the environment and the existence of stay cable on tethered type ship-based UAV,the designed control algorithm cannot heavily rely on the motion model of UAV,and so a control strategy with nominal Proportional and Differential(PD)controller plus disturbance observer is presented.Then the rules of choosing the parameters in disturbance observer are discussed.Furthermore,a design method of disturbance observer based on h-infinity optimization theory is proposed.And the effectiveness of the methods has been tested by simulation results.Finally,the PD controller plus disturbance observer is applied to a practical experiment of UAV position maintenance in the presence of wind.The results show that the control precision had been improved greatly with the application of disturbance observer,the accuracy of position of the UAV reaching a decimeter level under a strong wind field.