Research On Autonomous Flight And Application Of Inspection Quadrotor UAV

In recent years,the quadrotor UAV has overcome various defects of traditional inspection methods due to its advantages of high flexibility,simple structure,low cost,and vertical take-off and landing.It is widely used in power,bridges,roads and other areas of the inspection.The autonomous flying capability of the quadrotor UAV directly determines the degree of inspection effectiveness.As the keys technology in autonomous flight research,flight control technology and path planning technology have important research prospects and significance.For the flight control technology,firstly,the force of the quadrotor UAV under the wind field was analyzed according to the structure and flight principle.The Newton-Euler equation was used to establish the dynamic model under the wind field and the wind field was described.After determining the feasibility of controlling this system,the dynamic model of the quadrotor UAV in turbulent wind field was combined with the global fast terminal sliding mode control principle.In addition,the virtual control laws were introduced to design the switch surface of the global fast terminal sliding mode controller and the control laws of various degrees of freedom.The MATLAB/Simulink software was used to build each module of the quadrotor UAV system to verify the hovering and path tracking status.The results show that the controller has high reliability and robustness,and can be applied to the flight control of the inspection quadrotor UAV under disturbance of turbulent wind field.For the path planning technology,firstly,the mathematical model of TSP was established in the form of inspection missions.And the environment and airframe performance constraints of the quadrotor UAV in the flight space were analyzed.A Dubins path,which is commonly used in the drone route planning,was introduced as the calculation method of the route length.In order to obtain the method for solving the distance matrix in the TSP,the two-dimensional Dubins path is extended to a three-dimensional Dubins path that is suitable for the flight path planning of the inspection quadrotor UAV.Based on this,an improved firefly algorithm with adaptive local adjustment operator and 2-opt operator is designed.According to the characteristics of the TSP model the process of solving the TSP problem using this algorithm was determined.Then using MATLAB software to program and simulate the improved firefly algorithm.The simulation results show that the improved firefly algorithm can find the optimal solution stably and has good feasibility and stability.It is an effective algorithm for inspecting TSP path planning problems.Finally,in order to verify the autonomous flying capability of the inspection quadrotor UAV,it was applied to a specific bridge detection task and a simulation experiment was conducted.The results show that the inspection quadrotor UAV meet the actual needs of use that it can obtain an optimal flight path according to the requirements of the inspection mission,and accurately hover over each inspection node according to the path and the trajectory deviation during the flight is within the allowable value range.The study of autonomous flight of patrol quadrotor UAV is a meaningful and complex task.There is some reference value in the research of the quadrotor UAV about the design of the global fast terminal sliding mode controller,the introduction of the Dubins curve and the improvement of the firefly algorithm.