Research On Fault-Tolerant Control For Time-Delay Systems With Application To Quad-rotor UAV

With the development of modern production technology and the improvement of control technique,the level of equipment automation has been greatly increased and the composition of control system has been more and more complex.Especially in the flight control system with high expectations for security,different kinds of faults will occur easily.Under this background and demand,fault-tolerant control has developed fast and becomes a hotspot recently.In the complex fault-tolerant control systems,there always exist some nonlinear factors like time delay and uncertainty which will affect the robustness of the systems.Therefore,many scholars have searched for the fault-tolerant control of uncertain time-delay systems.On the basis of precious research,the fault diagnosis and fault-tolerant control methods are expanded in this paper and the proposed approaches are validated by the quad-rotor UAV(Unmanned Aerial Vehicle)in MCS.Firstly,the study background and significance are introduced and the current situation for fault diagnosis and FTC of time delay systems are reviewed.The dynamic model of quad-rotor UAV is analyzed and established.Then the composition and simulation steps of quad-rotor UAV MCS are introduced.Secondly,a passive FTC method based on integral SMC is proposed.A sufficient condition for the asymptotical stability of sliding motion is given based on Finsler's lemma and then a sliding mode FTC law is designed by equivalent control,which guarantee the stability of the systems after faults.Thirdly,an active FTC approach based on sliding mode observer is presented to deal with the unknown fault information.The delay compensation item is added to the traditional sliding mode observer and a delay dependent stability condition is given.Then an active FTC method based on adaptive SMC is designed to improve the fault-tolerant performance and reliability of the systems.Further,to enhance the dynamic performance for FTC of time delay system and optimize the controller,an improved robust FTC method based on optimal control is put forward.In the process of fault-tolerant controller design,the optimal control theory is introduced and a quadratic performance index is adopted to make the closed-loop system optimal.Finally,the methods mentioned above are respectively applied to the quad-rotor UAV MCS simulation platform,and stimulation results verify the feasibility and validity.