Research On Anti-disturbance Control Of Water-flushed Rotor UAV In Power System

In recent years,with the continuous progress of computer,microelectronics,chips,sensors and other hardware and software technologies,unmanned aerial vehi-cles(UAVs)begin to play an increasingly important role in various application scenar-ios.Compared with common fixed-wing UAVs,rotary-wing UAVs have many advan-tages,such as simple structure,strong maneuverability,flexible maneuverability and high safety.They are widely used in military,plant protection,aerial photography,goods transportation and other scenarios.Insulator is an important insulating element in power system.Because it has been working in the atmospheric environment,its surface is easy to form a layer of pollution,resulting in pollution flashover short circuit and other phenomena.In order to reduce economic losses,it is necessary to clean the surface of insulators regularly.At present,several commonly used methods for cleaning insulators in power systems include:man-ual cleaning after power failure,manned helicopter cleaning,vehicle-mounted water tank cleaning,etc.However,these methods are difficult to be popularized on a large scale because of their high cost,low security and poor ability to deal with emergencies.Based on the scientific research project of State Grid,this dissertation studies the use of UAV to carry water tank to clean insulators in transmission lines.No matter which application scenario,the stable flight of UAV and fast and ac-curate flight to the desired position and maintain corresponding attitude are the focus of people’s research.Among them,UAV will be disturbed from outside when flying,such as wind disturbance,electromagnetic interference,etc.,and will be affected by internal interference due to the changes of internal parameters and model uncertainty.Therefore,the anti-disturbance control of UAV is a crucial problem.For a long time,many experts and scholars have put forward many valuable achievements in the anti-disturbance control of UAV,but there are still some shortcomings.For example,the controller is difficult to solve,the complexity of the calculation process leads to poor real-time performance,and the lack of disturbance analysis.Considering the actual project application background,this dissertation designs the UAV position and attitude controller based on disturbance modeling and nonlinear control method,and verifies the control effect through numerical simulation experiment.This dissertation studies the anti-disturbance control of UAV against recoil force disturbance.Based on Newton’s second law and Euler’s equation,the dynamic equa-tions of position and attitude of the quadrotor UAV are established.In this disserta-tion,momentum theorem and Bernoulli equation are used to analyze and model the disturbance caused by the recoil force when the UAV flushing the insulators in the high voltage line.Then,the UAV system is divided into two closed-loop systems,the outer position loop and the inner attitude loop,and the corresponding controllers are designed by using the nonlinear control method,and the expected attitude Angle is calculated.On this basis,the anti-disturbance control of the UAV system is simulated numerically.The simulation results prove that the controller designed in this dissertation can effectively keep the UAV stable when it is disturbed by the recoil force.On this basis,this dissertation also considers that in addition to the disturbance of the recoil force,there will be other unknown external disturbances during the flight of the UAV.In this dissertation,sliding mode control is introduced to design the controller of the outer loop of UAV position and the inner loop of UAV attitude.At the same time,considering the chattering problem in the sliding mode control,and the internal disturbance caused by the uncertainty of the system model and the change of the system internal parameters,an extended state observer is introduced to improve and optimize the designed controller.The total disturbance of the system is compensated in real time in the controller,so the anti-disturbance ability of the system is improved effectively.The research background of this dissertation is the use of unmanned aerial vehi-cle(UAV)to carry out live water flushing of insulators in transmission lines in the power system.The research of this work not only expands the development direction for the aerial operation of the power industry,and puts forward a new way of flushing insula-tors with charged water,but also broadens the idea for the research of anti-disturbance control of UAV.According to the results of the simulation experiment,the UAV with live water flushing can effectively clean the insulators in the transmission line,and keep a stable flight in the process of flight and flushing,so as to successfully complete the task.