Terahertz Time-Domain Spectroscopy Rapid Data Acquisition Based on Closed-Loop Control

2015 ◽  
Vol 52 (4) ◽  
pp. 040401
Author(s):  
黄战华 Huang Zhanhua ◽  
胡子晓 Hu Zixiao ◽  
何明霞 He Mingxia ◽  
龙宁波 Long Ningbo ◽  
刘洋 Liu Yang
2014 ◽  
Vol 989-994 ◽  
pp. 3062-3069
Author(s):  
Heng Du ◽  
Bin Huang ◽  
Lin Wang ◽  
Shu Mei Chen

In the research and development of the precise closed-loop control system in large hydraulic press, the touch screen and PLC are frequently applied to design, debug and test for the system. Though a better closed-loop control characteristic can be acquired after repeated testing by this way, the comprehensive state data of hydraulic press are unable to get, which leads to a long research cycle and also restricts the maintenance and upgrade with the equipment in the later period. In order to obtain the whole state information of hydraulic press easily and effectively, a monitor system of precise closed-loop control in large hydraulic press is designed. Based on reasonable cooperation of sensors and high-speed data-acquisition card, high-speed and precise signal acquisition is realized. In addition, data-acquisition software program is designed base on LabVIEW, it can achieve the functions of collecting, storing, displaying and analyzing data. Through the real measuring and analyzing on a certain large ceramic hydraulic press, the status of key parameters can be acquired effectively during the whole pressing process. So the monitoring system supplies the significant data basis to the precise closed-loop control, accelerates the design and development of high characteristic precise closed-loop control and also strongly supports to the maintenance and upgrade with the equipments in the later period.


2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Yu-Hsing Chen ◽  
Catalin Gabriel Dincan ◽  
Philip Kjær ◽  
Claus Leth Bak ◽  
Xiongfei Wang ◽  
...  

This paper focuses on the modelling of the series resonant converter proposed as a DC/DC converter for DC wind turbines. The closed-loop control design based on the discrete time domain modelling technique for the converter (named SRC#) operated in continuous-conduction mode (CCM) is investigated. To facilitate dynamic analysis and design of control structure, the design process includes derivation of linearized state-space equations, design of closed-loop control structure, and design of gain scheduling controller. The analytical results of system are verified in z-domain by comparison of circuit simulator response (in PLECS™) to changes in pulse frequency and disturbances in input and output voltages and show a good agreement. Furthermore, the test results also give enough supporting arguments to proposed control design.


2020 ◽  
Vol 10 (4) ◽  
pp. 1443 ◽  
Author(s):  
Tomaž Kos ◽  
Mikuláš Huba ◽  
Damir Vrančić

Integrating systems are frequently encountered in the oil industry (oil–water–gas separators, distillation columns), power plants, paper-production plants, polymerisation processes, and in storage tanks. Due to the non-self-regulating character of the processes, any disturbance can cause a drift of the process output signal. Therefore, efficient closed-loop control of such processes is required. There are many PI and PID controller tuning methods for integrating processes. However, it is hard to find one requiring only a simple tuning procedure on the process, while the tuning method is based either on time-domain measurements or on a process transfer function of arbitrary order, which are the advantages of the magnitude optimum multiple integration (MOMI) tuning method. In this paper, we propose the extension of the MOMI tuning method to integrating processes. Besides the mentioned advantages, the extension provides efficient closed-loop control, while PI controller parameters calculation is still based on simple algebraic expressions, making it suitable for less-demanding hardware, like simpler programmable logic controllers (PLC). Additionally, the proposed method incorporates reference weighting factor b that allows users to emphasize either the disturbance-rejection or reference-following response. The proposed extension of the MOMI method (time-domain approach) was also tested on a charge-amplifier drift-compensation system, a laboratory hydraulic plant, on an industrial autoclave, and on a solid-oxide fuel-cell temperature control. All closed-loop responses were relatively stable and fast, all in accordance with the magnitude optimum criteria.


2006 ◽  
Vol 53 (4-5) ◽  
pp. 179-184 ◽  
Author(s):  
P.J. Smith ◽  
S. Vigneswaran ◽  
H.H. Ngo ◽  
H.T. Nguyen ◽  
R. Ben-Aim

The application of automation and supervisory control and data acquisition (SCADA) systems to municipal water and wastewater treatment plants is rapidly increasing. However, the application of these systems is less frequent in the research and development phases of emerging treatment technologies used in these industries. This study involved the implementation of automation and a SCADA system to the submerged membrane adsorption hybrid system for use in a semi-pilot scale research project. An incremental approach was used in the development of the automation and SCADA systems, leading to the development of two new control systems. The first system developed involved closed loop control of the backwash initiation, based upon a pressure increase, leading to productivity improvements as the backwash is only activated when required, not at a fixed time. This system resulted in a 40% reduction in the number of backwashes required and also enabled optimised operations under unsteady concentrations of wastewater. The second system developed involved closed loop control of the backwash duration, whereby the backwash was terminated when the pressure reached a steady state. This system resulted in a reduction of the duration of the backwash of up to 25% and enabled optimised operations as the foulant build-up within the reactor increased.


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