Fault Tolerant Control Of Quadrotor UAV Based On Sliding Mode Theory

Quadrotor Unmanned Aerial Vehicles,due to its small size,strong maneuverability and other advantages,is widely used in various fields.But its strong coupling,under the drive of the complex characteristics also causes it to be extremely easy to cause the fault,to the UAV itself and the surrounding thing to cause the serious loss.Therefore,in order to improve the security and reliability,it is very important to study the fault tolerant control of Quadrotor Unmanned Aerial Vehicles.According to the Quadrotor UAV actuator failure fault under control problems are studied,which is based on the theory of sliding mode control algorithm,designed three kinds of different fault tolerance,which is validated by simulation experiments,which can track the desired instruction,and to achieve certain performance index.The main research contents include:Firstly,for the Quadrotor Unmanned Aerial Vehicles fault types,combined with the dynamic and kinematic characteristics,by using the Newton Euler method,and gave the analysis of execution failure model and dynamic model of failure;Secondly,to design a fault tolerant control algorithm based on combined sliding mode for actuator failure.The algorithm divides the system into full actuated and underactuated two subsystems,using the terminal sliding mode to shorten the whole drive system stable time,improve the strong coupling problem,the common sliding mode to ensure the underactuated system,expected to converge in finite time at the same time,the expansion of the observer to compensate the fault input,the organic combination of the three in order to achieve better fault tolerant control.Thirdly,taking the fault into account for unknown dynamics,a fault-tolerant control algorithm based on two order sliding mode control is designed by using the strong robustness of sliding mode theory.This algorithm is different from most researchers directly gives the sliding surface coefficient,direct calculation of the coefficients of the stable condition of Holzer Chavez,and gives a detailed derivation;because the fault for the unknown dynamic,without changing the fault-tolerant control law,more practical.Fourthly,on the basis of this,an online iterative learning algorithm is introduced in order to avoid the high frequency chattering.A sliding mode observer based fault-tolerant control algorithm is designed.The algorithm can ensure the stability of the UAV system in the event of failure without the known unknown dynamic and the upper bound of the fault.Fifthly,the above three kinds of fault tolerant algorithms are in the simulation experiment,and the validity and robustness are verified.Finally,the three methods are compared and analyzed under the same conditions,and the advantages and characteristics are summarized.