| With the development of energy industry in our country,New type of patrol technology which represented by UAV is gradually being used.Unmanned aerial vehicles(UAVs)which are equipped with image acquisition,data transmission and other equipment are used to assist and even replace the traditional inspection of petroleum pipelines and power lines.At present,due to the simple structure,high mobility,easy operation,working efficiency and etc.Mainstream plant protection UAV are dominated by quadrotor which is the classic rotor UAV structure.The production and maintenance costs are low,and have broad market prospect and application value.Because of its simple structure,it has less stable performance compared with other multi-rotor UAV.So when working in the complex environment,it is vulnerable to random disturbance,which affects the height and attitude stability.Especially in the case of rotor component failures,it can not maintain a stable flight attitude,and is very easy to crash.Then it will result in serious secondary disasters.Compared with the quadrotor system,the hexa-rotor system has two more rotors,so it has the hardware redundancy condition to implement fault-tolerant control method.If combined with the advanced fault-tolerant algorithm,it will have great advantages in stability and security,and is more suitable for the security requirements of inspection industry.Therefore,this paper will take the hexa-rotor system as the platform for flight control method and Implementation of fault tolerant control algorithm.Firstly,this paper introduces the background of the subject and puts forward the application status and development bottleneck of UAV in petroleum pipeline routing inspection.And then the problems of mainstream patrol UAV in the market are analyzed.Then the research status and fault-tolerant controling development of UAV at home and abroad are summarized,and the research methods of predecessors are summarized.Aiming at the Common faults and fault tolerance problems existing in UAV patrol inspection at present,the solutions are put forward,and the main research contents are explained.Then,this paper introduces the flying principle of hexa-rotor UAV and according to the function of the plant protection UAV to design circuit schematic diagram and make cloth board,wiring and components welding to complete flight control board.On the basis of this,the flight control system is completed by software programming and system debugging is carried out to obtain satisfactory experimental results.Then,the system model of the X-type structure of the hexa-rotor UAV is built under the normal condition and the rotor fault condition.The moment of inertia of the body is calculated by the frame parameter,and the relationship of the voltage speed is determined by experiment.The system which lift coefficient and torque coefficient cannot be directly measured need to be identified,the ultimate UAV model is obtained.On this basis,the simulation experiment is carried out and good experimental results are obtained.Finally,for the better quality of flight quality and inspection effect,the security and reliability need to be improved.The layering design of UAV system is used to reduce the difficulty of design.The upper design is based on the sliding mode method,and its anti-jamming ability is brought into full play.Aiming at the buffeting problem of sliding mode and the deterioration of asymptotic stability caused by the introduction of saturation function,a new dynamic saturation function is proposed for optimization.On the design of control allocation strategy,aiming at rotor failure,the updating strategy of position and velocity parameters is optimized and improved based on particle swarm optimization(PSO),which improves the ability of the algorithm to jump out of the local optimal solution.And then it is reasonably applied to the control allocation algorithm.Through the final simulation experiment,it is confirmed that the fault tolerance and reliability of the system are improved. |
PDF Full Text Request