Satisfaction Uncertain Systems Under Multiple Fault Tolerant Control

With the increasing requirements on the reliability of engineering systems, faulttolerant control has received considerable attention in recent years. Fault tolerant controlcan improve the reliability of complex dynamic systems, which can not only guarantee thestability of the fault close-loop systems but also meet acceptable performance indicesconstrains. At present, most of the papers about fault tolerant control theory focus on thestability of the dynamic closed-loop system before and after the fault had happened, but thefault-tolerant controller design with multi-performance indices constraints is seldomconsidered. So, the problem of satisfactory fault control with multi-indices constrains arestudied in this dissertation. Based on a more practical and general model of actuatorfailures, the consistency theory on index constrains and the ranges of consistent indices areanalyzed in detail. Furthermore, the effective controller design method for systems withconstrains of consistent indices is provided. Some of conclusions are listed as follows:(1) The robust H-infinity satisfactory fault tolerant control system design for nonlinearuncertain time-delay systems with actuator failures is addressed. Based on linear matrixinequality approach, the consistency theory on robust stabilization index and H-infinityindex for nonlinear uncertain time-delay systems is set up. And sufficient conditions for theexistence of robust H-infinity fault tolerant controller are given in terms of LMIs.(2) The state feedback satisfactory fault tolerant controller design method is presentedfor linear uncertain systems with circular pole index, steady variance index or circular poleindex, H-infinity performance constraints. Via the LMI optimal technology, the admissibleranges of each performance are analyzed in detail. Additionally, an effective satisfactoryfault tolerant controller design step is set up.(3) The static output feedback satisfactory fault tolerant controller design method forlinear uncertain systems with assignable pole index, steady variance index and H-infinityindex constrains is produced. The range of steady variance upper index and H-infinityindex is analyzed in detail, and the two indices are consistent with assignable pole index.Based on the above consistent analysis, an effective satisfactory fault tolerant controllerdesign step is developed.(4) The satisfactory fault tolerant control system design method for lineardiscrete-time stochastic systems with uncertainties is investigated. The closed-loop systemsare guaranteed by the designed controller to meet the required constrains on sector poleindex, steady variance index and H-infinity index simultaneously. Meanwhile, the consistency of the performance indices mentioned earlier is also discussed forfault-tolerant control. Furthermore, the effective satisfactory fault-tolerant controller designmethod for systems with constrains of consistent indices is provided.(5) The problem of satisfactory fault tolerant control system design for linearuncertain systems with noncovex pole index, steady variance index and H-infinityconstrains is discussed. A more practical and general model of actuator failures is adopted.Based on linear matrix inequality approach, the consistency theory on sector pole index,steady variance index and H-infinity constrains is setup, and the ranges of consistentindices are analyzed in detail. The effective controller design step for systems withconstrains of consistent indices is provided.Finally, some open issues and the future work in satisfactory fault-tolerant control arediscussed.