Moving window local outlier probability(MWLo OP)is an outlier detecting method which was proposed for monitoring time-varying industrial processes;however,for the practical industrial processes,besides the time-varyin...
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Moving window local outlier probability(MWLo OP)is an outlier detecting method which was proposed for monitoring time-varying industrial processes;however,for the practical industrial processes,besides the time-varying characters caused by deactivation of catalyst,measuring instrument drifting and so on,the operation mode is often switched as the adjusting of the feedstock,changes in market demands and so *** the WMLo OP algorithm can deal with the time-varying process data,the multi-mode process data will lead to a mass of fault *** solve this problem,an external analysis moving window local outlier probability(EA-MWLo OP)algorithm is proposed in this *** external analysis is employed to eliminate the influence of operation mode change on the process data,then the MWLo OP method can deal with complex distribution time-varying data,and give an outlier ***,the corresponding statistic and control limit are constructed to detect the process *** addition,while the monitoring model updated,the control limit is not necessary to *** performance of this method is evaluated through a case study of a non-isothermal continuous stirred tank reactor(CSTR).
This paper considers sliding mode control for a class of uncertain switched systems with state and input *** employing a weighted sum of the input matrix,a common sliding surface is designed and the corresponding slid...
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ISBN:
(纸本)9781479900305
This paper considers sliding mode control for a class of uncertain switched systems with state and input *** employing a weighted sum of the input matrix,a common sliding surface is designed and the corresponding sliding mode dynamics is *** guarantee the asymptotic stability of the sliding motion,a switching signal based on the min-projection strategy is ***,it is shown that the state trajectories can be driven onto the specified sliding surface despite the presence of state and input delay and external ***,a numerical example is given to demonstrate the effectiveness of the proposed method.
In the process of chemical production, the phenomenon of control valve's stiction is very common. This phenomenon causes control loop oscillation and has a negative effect on the quality and cost of the product. T...
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The paper proposes a new encoding method inspired from the block chain technology, by which an operation sequence information and the corresponding machine information is integrated in an operation node and links all ...
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The paper proposes a new encoding method inspired from the block chain technology, by which an operation sequence information and the corresponding machine information is integrated in an operation node and links all operation nodes to form an operation list with pointer technology of C++ program language. Accordingly, the paper designs an individual unit ID for every possible cases. Subsequently, it describes the process of searching the optimal solution of FJSP by implementing an improved UKPK-PSO algorithm, which hybridizes a varied PSO algorithm by getting the best information from K informants and the method of keeping the elitists for next generation in iterations. With the improved algorithm we can more efficiently traverse the solution space. After obtained some better solutions with the improved PSO, we continuously search the optimal solutions by tentatively changing the chosen machines of the dominant operations. Finally, it outputs the optimal solution through some limited iterations again. By analyzing the experiment results for the instances, the paper furtherly proves that the whole algorithm is effective for FJSP.
In practical control engineering,delay and actuator saturation are main challenges which may lead to system performance degradation,or even controlled variables *** of Smith predictor and model recovery anti windup me...
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In practical control engineering,delay and actuator saturation are main challenges which may lead to system performance degradation,or even controlled variables *** of Smith predictor and model recovery anti windup method is an effective solution to linear delay system anti-windup synthesis,however model dependent property of the above two methods brings obstacles for the application and *** overcome such a difficulty,a data-driven approach is proposed in this paper,operating data is collected and utilized to simultaneously tune feedback controller parameters and estimate internal model applied in Smith ***,anti-windup compensator is constructed with the estimated model and a compensator gain optimization structure is proposed based on Lyapunov ***,simulations have been implemented to three typical processes in chemical engineering,and detailed performance comparison is provided to illustrate the effectiveness of the proposed method.
In this study, a novel online operating performance assessment method based on multi-sets two-step basis vector extraction artificial neural networks (MTBVE-ANN) strategy is proposed for industrial applications. The M...
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In this paper,a novel dimensionality reduction method,time space coordinated-locality preserving projections(TSCLPP) is proposed based on locality preserving projection(LPP).For the short sampling interval,except the ...
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In this paper,a novel dimensionality reduction method,time space coordinated-locality preserving projections(TSCLPP) is proposed based on locality preserving projection(LPP).For the short sampling interval,except the data correlation in spatial scale,there exists data correlation in time scale as *** considering the correlation of sampling points in time and spatial scale simultaneously,TSCLPP constructs the adjacency graph by selecting adjacent points in time-sequence and Euclidean distance ***,the importance of the time-sequential neighbors is measured by the weight based on a time distance.A dual objective function with a weight index coordinating the relationship between time and space is constructed to compute the transformation ***'s T2 and squared prediction error(SPE) are established for process monitoring.A numerical case and the Tennessee-Eastman Process(TEP) are employed for the experimental verification.
Gaussian mixture model (GMM) monitoring method is commonly used for non-Gaussian process monitoring. In GMM monitoring method, the final number of Gaussian components and the statistical distribution parameters are es...
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Gaussian mixture model (GMM) monitoring method is commonly used for non-Gaussian process monitoring. In GMM monitoring method, the final number of Gaussian components and the statistical distribution parameters are estimated through the improved Figueiredo-Jain (F-J) algorithm in the modeling phase. However, the data dimensionality of modern industry is high, the number of initial Gaussian components is large for the accuracy of the algorithm. Under this condition, the relative small number of samplings makes the denominator in the weight estimation formula of the improved F-J algorithm become zero and the algorithm suspends. To make the algorithm work well in an acceptable modeling time, we deduce the Initial-Parameter-Criterion among initial Gaussian components, data dimension, sampling number and propose the Initial-Parameter-Criterion based GMM (IPC-GMM) monitoring method. The proposed monitoring method is used for TE process monitoring, simulation results reveal the effectiveness and necessity of IPC-GMM monitoring method.
In order to segment ban traffic signs quickly and accurately, this paper first refers to its characteristic of red circle and white background to start color segmentation, then presents a segmentation method based two...
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Due to the characteristics of source limited, multi-to-one paths and burst data flow, congestion inevitable happens in wireless sensor networks(WSNs). The control mechanism of congestion for WSNs is of high significan...
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ISBN:
(纸本)9781479937097
Due to the characteristics of source limited, multi-to-one paths and burst data flow, congestion inevitable happens in wireless sensor networks(WSNs). The control mechanism of congestion for WSNs is of high significant and plays a key role in achieving high QoS of the network. In this paper, many existing congestion control mechanisms have been summarized and compared, some interesting topics have been provided.
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