Fault-Tolerant Bumpless Switching Control For Switched Systems

The rapid development of human industrialization process makes the exploration of advanced control technology endless.In practice,two kinds of control issues have attracted considerable attention of the automation technology researchers: fault-tolerant control and bumpless switching control.In practical engineering,burst faults happened to the system are fairly common problems.The unwanted faults in the systems may induce undesired behaviors or even cause disastrous consequence.Thus,the study of fault-tolerant control has been the focus and main content in control field.The application of fault-tolerant control not only improves the stability of actual systems,but also ensures the safety.In this thesis,the problem of fault-tolerant bumpless switching control for switched systems with sensor faults is studied.Due to the complexity of actual systems,a single controller may not fulfill satisfactory control performance.Then the concept of switching control is widely used in practice,i.e.switching between different controllers to achieve multiple specific goals.The adopted switching fault-tolerant control framework is to switch between two kinds of controllers(one is for normal use and the other is for fault-tolerance)to achieve the desired fault-tolerance performance.In addition,although switching control can significantly improve the system performance,it also incurs some problems.For instance,the system may suffer unwanted transient response because of the discontinuous control input at the controller switching instant.Thus,within the framework,how to achieve bumpless transfer is an important issue to be resolved.Based on sliding mode control,three kinds of bumpless transfer compensators are proposed in this paper.By the reasonably designed compensators the output of the off-line controller can track that of the online controller,therefore the control input of the switched systems can attain “smoothness” during the switching process.The contribution of this paper can be concluded in threefold.1.Bumpless switching control for switched systems with sensor loss failures.2.Fault observer based bumpless switching control for switched systems.3.Bumpless switching control for switched Takagi-Sugeno fuzzy systems.