The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Xuedan Zhang - One of the best experts on this subject based on the ideXlab platform.
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Locating gas pipeline leakage based on stimulus-Response Method
Energy Procedia, 2014Co-Authors: Tiantian Zhang, Yufei Tan, Jinhui Zhao, Hongxing Yang, Xuedan ZhangAbstract:Gas pipeline leakage leads to significant environmental damages, industrial hazards and personal injuries, so detecting and locating the leakage location without delay is essential to lighten or avoid its harms. The stimulus-Response Method, a newly proposed technique of pipeline leakage detection and location has received much attention for its benefit of strong detecting signal and high positioning accuracy. In this paper, firstly, a complete set of gas pipeline leakage experimental device was built on the basis of stimulus-Response Method. Secondly, three leakage points were designed and tested to investigate the positioning accuracy. Finally, the impacts of aperture size and incentive intensity on positioning result were evaluated, and the detectable aperture size and minimum incentive intensity were determined. The results show that under fully-closed condition of the terminal valve, the minimum pore size that can be detected is 2 mm in the experimental tests (with an aperture ratio of 4 percent). It is expected that the outcomes can provide reference for improving localization Methods of gas pipeline leakage.
Karl Johan Åström - One of the best experts on this subject based on the ideXlab platform.
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revisiting the ziegler nichols tuning rules for pi control part ii the frequency Response Method
Asian Journal of Control, 2008Co-Authors: Tore Hägglund, Karl Johan ÅströmAbstract:This paper presents an analysis of the Ziegler-Nichols frequency Response Method for tuning PI controllers, showing that this Method has severe limitations. The limitations can be overcome by a simple modification for processes where the time delay is not too short. By a major modification it is possible to obtain new tuning rules that also cover processes that are lag dominated.
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Revisiting the Ziegler-Nichols step Response Method for PID control
Journal of Process Control, 2004Co-Authors: Tore Hägglund, Karl Johan ÅströmAbstract:The Ziegler-Nichols step Response Method is based on theidea of tuning controllers based on simple features of thestep Response. In this paper this idea is investigated fromthe point of view of robust loop shaping. The results are:insight into the properties of PI and PID control andsimple tuning rules that give robust performance for processes with essentially monotone step Responses.
Jörg Kärger - One of the best experts on this subject based on the ideXlab platform.
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Application of the thermal frequency Response Method and of pulsed field gradient NMR to study water diffusion in zeolite NaX
Adsorption, 1996Co-Authors: Vincent Bourdin, Andreas Germanus, Philippe Grenier, Jörg KärgerAbstract:The thermal frequency Response and pulsed field gradient NMR Methods are applied in a comparative study of water diffusion in zeolite NaX under non-equilibrium and equilibrium conditions. The obtained results are found to be in satisfactory agreement with each other, indicating that by applying the thermal frequency Response Method, complications due to uncontrolled water adsorption at the chamber walls inherent in conventional frequency Response measurements may be circumvented.
Tiantian Zhang - One of the best experts on this subject based on the ideXlab platform.
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Locating gas pipeline leakage based on stimulus-Response Method
Energy Procedia, 2014Co-Authors: Tiantian Zhang, Yufei Tan, Jinhui Zhao, Hongxing Yang, Xuedan ZhangAbstract:Gas pipeline leakage leads to significant environmental damages, industrial hazards and personal injuries, so detecting and locating the leakage location without delay is essential to lighten or avoid its harms. The stimulus-Response Method, a newly proposed technique of pipeline leakage detection and location has received much attention for its benefit of strong detecting signal and high positioning accuracy. In this paper, firstly, a complete set of gas pipeline leakage experimental device was built on the basis of stimulus-Response Method. Secondly, three leakage points were designed and tested to investigate the positioning accuracy. Finally, the impacts of aperture size and incentive intensity on positioning result were evaluated, and the detectable aperture size and minimum incentive intensity were determined. The results show that under fully-closed condition of the terminal valve, the minimum pore size that can be detected is 2 mm in the experimental tests (with an aperture ratio of 4 percent). It is expected that the outcomes can provide reference for improving localization Methods of gas pipeline leakage.
Tore Hägglund - One of the best experts on this subject based on the ideXlab platform.
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revisiting the ziegler nichols tuning rules for pi control part ii the frequency Response Method
Asian Journal of Control, 2008Co-Authors: Tore Hägglund, Karl Johan ÅströmAbstract:This paper presents an analysis of the Ziegler-Nichols frequency Response Method for tuning PI controllers, showing that this Method has severe limitations. The limitations can be overcome by a simple modification for processes where the time delay is not too short. By a major modification it is possible to obtain new tuning rules that also cover processes that are lag dominated.
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Revisiting the Ziegler-Nichols step Response Method for PID control
Journal of Process Control, 2004Co-Authors: Tore Hägglund, Karl Johan ÅströmAbstract:The Ziegler-Nichols step Response Method is based on theidea of tuning controllers based on simple features of thestep Response. In this paper this idea is investigated fromthe point of view of robust loop shaping. The results are:insight into the properties of PI and PID control andsimple tuning rules that give robust performance for processes with essentially monotone step Responses.