Optimizing anaerobic co-digestion plants: MIR online instrumentation and dynamic real-time substrate feed optimization

2015 ◽  
Vol 63 (7) ◽  
Author(s):  
Daniel Gaida ◽  
Christian Wolf ◽  
Robin Eccleston ◽  
Michael Bongards

AbstractClosed-loop control of the substrate feed as well as the application of online instrumentation are important to achieve optimal biogas plant operation. Therefore, this paper presents two novel approaches for online instrumentation and control to achieve optimal AD plant operation based on middle-infrared spectroscopy on the one hand and nonlinear model predictive control on the other hand. At present, research into both techniques is being performed separately, with the intention that in the future the spectroscopic measurements will be integrated into the control loop.




Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 121 ◽  
Author(s):  
Yanru Zhao ◽  
Xiaojie Huang ◽  
Yong Liu ◽  
Geng Wang ◽  
Kunpeng Hong

A piezoelectric-driven microgripper with three-stage amplification was designed, which is able to perceive the tip displacement and gripping force. The key structure parameters of the microgripper were determined by finite element optimization and its theoretical amplification ratio was derived. The tracking experiments of the tip displacement and gripping force were conducted with a PID controller. It is shown that the standard deviation of tracking error of the tip displacement is less than 0.2 μm and the gripping force is 0.35 mN under a closed-loop control. It would provide some references for realizing high-precision microassembly tasks with the designed microgripper which can control the displacement and gripping force accurately.



Author(s):  
William J. Emblom

Methods for improving the robustness of panel forming including the introduction of process sensing and feedback and control has resulted in significant gains in the quality of parts and reduced failures. Initial efforts in implementing closed-loop control during panel forming used active tool elements to ensure that the total punch force followed prescribed trajectories. However, more recently local forces within the tooling have been demonstrated to not only follow desired force trajectories but have been shown to increase the operational envelope of the tooling compared to open-loop tests and even closed-loop test where the total punch force had been controlled. However, what has not been examined is the effect of local force, especially during closed-loop control panel forming operations on the total punch force measured during forming. This paper addresses this by comparing the results of both open-loop tests and closed-loop tests and examining the effects on both local and total punch forces. It was found that while open-loop forming with various constant draw bead depths resulted in varying total punch forces, once closed-loop control was implemented the total punch forces followed virtually identical trajectories. The tooling for this project included local force transducers and a total punch force transducer. In addition, active draw beads could be controlled during forming and a flexible blank holder with variable blank holder forces were part of the setup.



2019 ◽  
Vol 80 ◽  
pp. 202-210 ◽  
Author(s):  
Jose Garcia-Tirado ◽  
John P. Corbett ◽  
Dimitri Boiroux ◽  
John Bagterp Jørgensen ◽  
Marc D. Breton




2017 ◽  
Vol 19 (6) ◽  
pp. 331-339 ◽  
Author(s):  
Lauren M. Huyett ◽  
Trang T. Ly ◽  
Gregory P. Forlenza ◽  
Suzette Reuschel-DiVirgilio ◽  
Laurel H. Messer ◽  
...  


2010 ◽  
Vol 139-141 ◽  
pp. 1852-1855
Author(s):  
Cheng Xue ◽  
Yu Shi ◽  
Ding Fan ◽  
Hao Zhong ◽  
Ming Xiao Shi

Dual-bypass MIG welding (DB-GMAW) is a new kind of high speed MIG welding with three arcs. In order to monitor the weld process and control it, a high speed weld system of DB-GMAW was built. The system was run by LabVIEW programs, including getting data of system and control output signals. The test result of system showed that all equipments could be used in the same time. Beside images of weld pool and arc, the weld voltages and currents of every part had been acquired. The signals of bypass current and weld speed also had been input TIG welding sources and worktable motor successfully. Meanwhile, the high speed weld formation had a good quality, and all of these established the closed-loop control of high speed DB-GMAW.



Author(s):  
William J. Emblom ◽  
Klaus J. Weinmann ◽  
John E. Beard

An experimental evaluation of the strains in an oval stamp forming die is presented. The die design included a flexible blank holder and active draw beads. The die was instrumented with local punch force and wrinkle sensors and control systems were developed in order to follow local punch force and wrinkle trajectories. Strains were measured after pan forming for both open and closed-loop tests. The relation between blank holder force, draw bead penetration, and strains were explored in the critical strain region of the formed pan. Closed-loop control of the local punch forces at the die ends was established using blank holder forces. The strains for tests with various lubrication conditions and draw bead penetrations were compared. It was observed that there is a tendency for the strains in critical locations to converge or remain constant for the closed-loop control tests while the strains tended to increase with blank holder force for open-loop tests. It was concluded that by controlling local punch forces, strain is indirectly controlled.



2016 ◽  
Vol 106 (10) ◽  
pp. 684-689
Author(s):  
M. Prof. Liewald ◽  
M. Barthau ◽  
S. Braun

Am IFU der Universität Stuttgart wurde ein Regelkreis für das Tiefziehen entwickelt, welcher einen regelnden Eingriff in den Tiefziehvorgang während des Hubes erlaubt. Die Umsetzung dieses Regelungskonzeptes erfolgte mittels eines Ziehwerkzeugs, das an eine vereinfachte Geometrie eines PKW-Vorderkotflügels angelehnt ist. Beschrieben werden die messtechnische Ausstattung des Versuchswerkzeugs, der Aufbau des Regelkreises und die Entwicklung der Regelstrategie. Des Weiteren werden die Ergebnisse der Simulation sowie der ersten Versuche dargestellt.   At IFU, University of Stuttgart a control loop for deep-drawing process, with control intervention during deep-drawing stroke was developed. The closed-loop control was demonstrated on a fender shaped geometry. Described are the measurement devices, design of the closed-loop and the featured control strategies. Results of simulation and sensitivity analysis are also shown.



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