Research On The Control System Of Automatic Cable-Roll Device For Tethered UAV

The tethered UAV is an important branch of the unmanned aerial vehicle.By combining the traditional multi-rotor UAV with the technology of tethered aerostat,the system can sufficiently improve the duration of flight,meeting the requirement of round-the-clock patrol monitoring,exploration,and investigation.As the hub for connecting the base station and the tethered UAV,the roll-cable device must ensure that the UAV movement is well followed by the cable,so as to ensure the steady and normal operation of the tethered aircraft.The control system is a typical constant tension control system.We need to design rational structure scheme and control strategy to insure the load validity,minimizing the tension fluctuation caused by the tethered objective movement.The main contents include the following aspects:This paper introduces the basic working principle of unmanned rotorcrafts and the components of roll-cable device,also proposing structure schemes and the overall design of the control system according to the given design requirements.The control system design includes the hardware general scheme and the control strategy,covering the flat flight control strategy and retraction control strategy.This paper gives detailed hardware design,including communication module design,power module design,drive module design,signal acquisition module design and safety module design,and offers detailed explaination and analysis on essential parts.The characteristics of the tether cable under different working circumstances are particularly analyzed by modeling the taut rope.Design active force servo control strategy,and tune the parameters of controller with usage of MATLAB/Simulink to ensure the system having sufficient tracking accuracy and response speed.Design passive force servo control strategy on the basis of active control strategy,including flat flight control strategy based on velocity compensation and the retraction control strategy based on position impedance control,aiming to improve the performance of disturbance resistance.A rational experiment is designed to verify different control strategies using semi-physical simulation platform,and the experimental results are analyzed.A field experiment is conducted to verify whether the control strategy can still demonstrate effective anti-disturbance performance in the case of random movement of UAV.