Quality-related fault detection and diagnosis (QrFDD) is an emerging research subject in the field of multivariate statistical process monitoring and has received great attention from academia and industry in recent years. Compared with traditional multivariate statistical process monitoring methods, QrFDD methods can decompose the process variable space into orthogonal subspaces according to the correlation between input and output so that faults affecting output and faults that do not affect output can be diagnosed in different subspaces. Thanks to this feature, the QrFDD methods have important application values in reducing unnecessary maintenance time and costs, as well as improving production efficiency. Since the decade so far proposed, many outstanding research results have been produced; however, the technical route and implementation algorithm of these achievements are not all the same. In this chapter, we will conduct a technical review and summary of the classical achievements, including their principles, implementation algorithms, technical advantages, and defects. At the same time, we will introduce some of our latest research results and look forward to the future development trend of QrFDD from the perspectives of technology and demand.
Despite the fact that the zero-forcing block-linear equalizer (ZF-BLE) represents an entry-level solution to the joint-detection problem as applied to the TD-CDMA air-interface proposal for UMTS, it is nevertheless accompanied by a prohibitive computational complexity when supporting long data sequences, multiple users and channels with long impulse responses. A primary contributor to this computational complexity is the need to perform a Cholesky factorization of a sparse yet large correlation matrix. This paper presents a novel technique which exploits the pseudo block-Toeplitz nature of the Cholesky factor to derive an approximate triangular factorization, thereby allowing significant reductions in computational complexity and finite-precision effects at the expense of little or no degradation in performance. The technique is equally applicable to other block-based linear or decision-feedback joint-detection schemes whose operation relies on the Cholesky factorization.
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Summary The problem of robust leader‐following consensus of heterogeneous multiagent systems subject to deny‐of‐service attacks is investigated, where attack strategies are partially unknown and uncertain to defender. A Markovian jump system approach is proposed, that is, capable of describing the occurrence of different attack strategies, and the occurring probability of each attack strategy is represented by the transition probability of the Markovian jump model. Then, sufficient conditions are derived such that the output tracking performance can be guaranteed. In order to design the controller gains, some slack matrices are introduced, which can provide some design freedom. Finally, it is shown that the controller design results can be applied to the multivehicle position‐tracking system. The simulation results reveal that the consensus performance is much better if one has more statistics information on attacks.
In this work, the sliding mode control (SMC) problem is addressed for the discrete‐time interval type‐2 fuzzy singularly perturbed systems. A component‐based dynamic event‐triggering scheme is first proposed to determine the transmission of each measurement component according to the prespecified triggering condition, under which each sensor node will transmit independently its signal to the controller. Meanwhile, the SMC approach is used to design an effective interval‐type‐2 fuzzy controller by only utilizing the transmitted component signals, and the ‐independent conditions are developed to attain the stability of the closed‐loop system and the reachability of the sliding domain. In addition, a framework of the optimization control design is established, where the learning‐based iterative optimization algorithm is proposed via reducing the convergence domain around the sliding surface. Finally, the proposed SMC scheme is verified via the simulation results.
For locating inaccurate problem of the discrete localization criterion proposed by Demigny, a new criterion expression of “good localization” is proposed. Firstly, a discrete expression of good detection and good localization criterion of two dimension edge detection operator is employed, and then an experiment to measure optimal parameters of two dimension Canny's edge detection operator is introduced after. Moreover, a detailed performance comparison and analysis of two dimension optimal filter obtained via utilizing tensor product for one dimension optimal filter are provided which can prove that least square support vector regression (LS-SVR) is a smoothness filter and give the construct method of the derivate operator. This paper uses LS-SVR as the object function constructor and then realizes the approximation of two dimension optimal edge detection operator. This paper proposes the utility method of using singleness operator to realize multiscale edge detection by referencing the multiscale analysis technology of the wavelets theory. Experiment shows that the method has utility and efficiency.
In this brief, we study the problem of output tracking for continuous-time stochastic dynamical systems with parametric uncertainties and aperiodic disturbances by using a modified repetitive controller (MRC). More precisely, the MRC is obtained based on the equivalent input disturbance (EID) technique such that the closed-loop modified repetitive-control system is asymptotically stable in the presence of uncertainties and aperiodic disturbances. The main advantage of the proposed controller is that it can incorporate an EID estimator, which estimates and eliminates disturbances in the repetitive-control systems. Finally, simulation is conducted to reveal that the proposed controller can effectively reject the aperiodic disturbance, reduce the stochastic noise, and track the reference signal without steady-state error.
No abstract is provided for this article.
Complex Engineering Systems are generally represented in terms of a set of interconnected systems that their collective/global behaviors/properties are somewhat difficult to be predicted or managed. The context of complex engineering systems is mainly concerned with developing multi-component engineering systems, designs, or algorithms to exploit those unpredictable collective/global behaviors/properties. Complexity in Engineering Systems is in general manifested in component, product, system, interconnections of interacting subsystems or multidisciplinary system designs. In a broad sense, complexity is related to the expected amount of information may need to describe a dynamical system.