Study On Fault Detection Of Observer Design Method

With the networked control and full digital control becoming the main stream of control system design, the problem of networked control system has ignited enormous attentions. Compare with the traditional control system, the networked control system is with many advantages including the configuration of low cost, easy installation, easy for system diagnosis and so on. Therefore, it is widely used in manufacturing industry, aircraft, automobile, power system etc. However, the introducing of the network to the systemcaused new problems, such as quantization, fault, delay and packet loss etc. In the conventional design, without considering the effect of quantization, so when the system quantization occurs, it will lead to system performance degradation and even instability.In addition, due to the increasing demand for reliability and safety in industrial processes, fault detection has been the subject of intensive research. Especially the study of the fault detection problem in finite frequency domain is with more realistic and gets the attention of scholars.Based on the previous works, this thesis investigates the robustness guaranteed costcontrol for discrete-time systems with dynamic quantization, the design problem of quantized fault detection filter and fault detection observer in finite frequency domain. Simulation examples illustrate the advantages and effectiveness of our approaches.Chapters1-2summarize the development and main research methods in faultdetection literature, give some preliminaries about the considered problem.Chapters3investigate the robust state feedback guaranteed cost control problem fordiscrete-time systems with signal quantization is studied. The quantizer considered hereis dynamic and composed of an adjustable “zoom” parameter and a static quantizer. Theinterval type of uncertainties is considered for describing the system uncertainty. Andthe vertex separator method is employed to give LMI(linear matrix inequality)-basedcontroller design conditions. By using the designed controller, a dynamic quantization control strategy is proposed with updating the quantizer’s parameter such that thesystem is asymptotically stable and the performance index is with a upper bound.Finally, an example is presented to illustrate the effectiveness of the control strategy.Chapters4focus on the integrated the fault estimations problem for networkedcontrol systems with signal quantization is considered. With the logarithmic quantizerconsideration, the recently developed Generalized Kalman-Yakubovich-Popov (GKYP)Lemma is exploited to formulate the quantized fault estimation filter design probleminfinite frequency domain. The quantzied measurement signals are dealt with byutilizing the sector bound method, in which the quantization error is treated assector-bounded uncertainty. LMI-based conditions are given to design the quantizedfilter to make the error between residual and fault as small as possible despite of thedisturbance effects and quantization errors. And a numerical example is given toillustrate the the effectiveness of the proposed method.Chapter5investigates the fault detection problem in the finite frequency domainfor networked control systems with signal quantization is considered. With thelogarithmic quantizer consideration, a quantized fault detection observer is designed byemploying a performance index which is used to increase the fault sensitivity in finitefrequency domain. The quantized measurement signals are dealt with by utilizing thesector bound method, in which the quantization error is treated as sector-boundeduncertainty. By using the Kalman-Yakubovich-Popov (GKYP) Lemma, an iterativeLMI-based optimization algorithm is developed for designing the quantized faultdetection observer. And a numerical example is given to illustrate the effectiveness ofthe proposed method.Finally, the results of the dissertation are summarized and further research topicsare pointed out.