Experimental Testing and Analysis of Inerter Devices

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Christos Papageorgiou ◽  
Neil E. Houghton ◽  
Malcolm C. Smith
Keyword(s):  
Closed Loop ◽  
Experimental Testing ◽  
Hydraulic Damper ◽  
Basic Model ◽  
Wide Range ◽  
In Series ◽  
Mechanical Element ◽  
Mechanical Devices ◽  
The Ideal ◽  
Loop Stability

This paper presents a first in-depth experimental study of mechanical devices that are designed to approximate the dynamics of the ideal inerter, which is a two-terminal mechanical element analogous to the ungrounded capacitor. The focus of the paper is experimental testing and identification of stand-alone inerter devices as well as the study of practical issues involved in their feedback control using standard hydraulic damper test rigs. Two contrasting inerter embodiments are studied, one in which a flywheel is driven by a rack-and-pinion mechanism and the other employing a ballscrew. Due to the fact that the ideal inerter is a dynamic element whose admittance function is 90 deg out of phase with that of the ideal damper, particular attention is needed to ensure closed-loop stability in testing using standard hydraulic damper test rigs. As expected, instability is observed in default configurations, and it is seen to manifest itself in a nonlinear manner with backlash playing a significant role. By using a basic model of the hydraulic rig and a model of an ideal inerter with backlash, the nature of the instability is reproduced and explained in a qualitative way. To achieve closed-loop stability without the need to redesign the controller as a function of the load, a methodology is proposed involving the design of a mechanical buffer network to be connected in series with the inerter device. It is demonstrated that this approach removes the instability problem for a wide range of inertance loads. Finally, the dynamic characteristics of the inerter devices are identified. It is verified experimentally that the admittance of the devices approaches the ideal inerter admittance over a useful frequency range and that friction in the devices is a major source of deviation from the ideal inerter behavior.

scholarly journals The IDEAL household energy dataset, electricity, gas, contextual sensor data and survey data for 255 UK homes

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Martin Pullinger ◽  
Jonathan Kilgour ◽  
Nigel Goddard ◽  
Niklas Berliner ◽  
Lynda Webb ◽  
...  
Keyword(s):  
Survey Data ◽  
Energy Demand ◽  
Secondary Data ◽  
Hot Water ◽  
Power Measurement ◽  
Sensor Data ◽  
Energy Awareness ◽  
Household Energy ◽  
Wide Range ◽  
The Ideal

AbstractThe IDEAL household energy dataset described here comprises electricity, gas and contextual data from 255 UK homes over a 23-month period ending in June 2018, with a mean participation duration of 286 days. Sensors gathered 1-second electricity data, pulse-level gas data, 12-second temperature, humidity and light data for each room, and 12-second temperature data from boiler pipes for central heating and hot water. 39 homes also included plug-level monitoring of selected electrical appliances, real-power measurement of mains electricity and key sub-circuits, and more detailed temperature monitoring of gas- and heat-using equipment, including radiators and taps. Survey data included occupant demographics, values, attitudes and self-reported energy awareness, household income, energy tariffs, and building, room and appliance characteristics. Linked secondary data comprises weather and level of urbanisation. The data is provided in comma-separated format with a custom-built API to facilitate usage, and has been cleaned and documented. The data has a wide range of applications, including investigating energy demand patterns and drivers, modelling building performance, and undertaking Non-Intrusive Load Monitoring research.

scholarly journals A reinforcement learning method with closed-loop stability guarantee for systems with unknown parameters

2020 ◽  
Vol 53 (2) ◽  
pp. 8157-8162
Author(s):  
Thomas Göhrt ◽  
Fritjof Griesing-Scheiwe ◽  
Pavel Osinenko ◽  
Stefan Streif
Keyword(s):  
Reinforcement Learning ◽  
Closed Loop ◽  
Learning Method ◽  
Unknown Parameters ◽  
Loop Stability

A closed-loop wide-range tunable mechanical resonator for energy harvesting systems

2009 ◽  
Vol 19 (9) ◽  
pp. 094004 ◽  
Author(s):  
Christian Peters ◽  
Dominic Maurath ◽  
Wolfram Schock ◽  
Florian Mezger ◽  
Yiannos Manoli
Keyword(s):  
Energy Harvesting ◽  
Closed Loop ◽  
Mechanical Resonator ◽  
Wide Range ◽  
Harvesting Systems

Gearbox (China) Ltd.: Will the Company's ERP System Support its Ambitious Growth Strategy?

2004 ◽  
Vol 19 (2) ◽  
pp. 140-148 ◽  
Author(s):  
Kai Reimers
Keyword(s):  
Operations Management ◽  
Emerging Market ◽  
Growth Strategy ◽  
Medium Size ◽  
Cultural Issues ◽  
Erp System ◽  
Organizational Behaviour ◽  
Main Challenge ◽  
Wide Range ◽  
Mechanical Devices

This case describes the experience of a wholly foreign-owned manufacturing company in Tianjin/China regarding the use of its ERP system in its main functional departments, purchasing, production planning, sales/distribution, and finance. The company is part of a group which is a global leader in the manufacturing and distribution of mechanical devices, called gearboxes, that are needed to drive a wide range of facilities such as escalators and baggage conveyor belts in airports. It has entered China in 1995 and the Tianjin manufacturing facility has soon become a hub for the Asian market. The main challenge confronting the management team is to support the breakneck growth rate of this young company. The company's ERP system plays a crucial role in this task. However, it seems that middle managers are frequently hitting an invisible wall when trying to expand the use of the ERP system in order to cope with ever-increasing workloads and coordination tasks. This case serves to illustrate cultural issues implicated in the use of an enterprise wide information system in a medium size company operating in an emerging market economy. In addition, issues of operations management, global management, and organizational behaviour are addressed.

Numerical Simulation of Droplet Generation in Series Co-Flow Capillaries

2009 ◽  
Author(s):  
Yanxi Song ◽  
Jinliang Xu
Keyword(s):  
Reynolds Number ◽  
Disperse Phase ◽  
Weber Number ◽  
Three Dimensional ◽  
Continuous Phase ◽  
Disperse Flow ◽  
Double Emulsions ◽  
Wide Range ◽  
In Series ◽  
Dispersed Phases

We study the production and motion of monodisperse double emulsions in microfluidics comprising series co-flow capillaries. Both two and three dimensional simulations are performed. Flow was determined by dimensionless parameters, i.e., Reynolds number and Weber number of continuous and dispersed phases. The co-flow generated droplets are sensitive to the Reynolds number and Weber number of the continuous phase, but insensitive to those of the disperse phase. Because the inner and outer drops are generate by separate co-flow processes, sizes of both inner and outer drops can be controlled by adjusting Re and We for the continuous phase. Meanwhile, the disperse phase has little effect on drop size, thus a desirable generation frequency of inner drop can be reached by merely adjusting flow rate of the inner fluid, leading to desirable number of inner drops encapsulated by the outer drop. Thus highly monodisperse double emulsions are obtained. It was found that only in dripping mode can droplet be of high mono-dispersity. Flow begins to transit from dripping regime to jetting regime when the Re number is decreased or Weber number is increased. To ensure that all the droplets are produced over a wide range of running parameters, tiny tapered tip outlet for the disperse flow should be applied. Smaller the tapered tip, wider range for Re and we can apply.

MEMS Challenge: Can This Technology Catch the Internet Lightwave?

2000 ◽  
Author(s):  
Ken Gilleo
Keyword(s):  
Optical Switch ◽  
The Internet ◽  
Underwater Communications ◽  
Optical Mems ◽  
Phone Calls ◽  
Micro Bubble ◽  
Mechanical Devices ◽  
Final Answer ◽  
The Right ◽  
The Ideal

Abstract The pundits of the money world tell us to be a “dotcom” or enable them for excitement and rewards. Traffic on the Internet Highway is certainly stepping up the pace as “slow” electrons make way for ultimate-speed photons creating major hardware opportunities. The “Copper Road” has become the “Glass Super Highway” as long-haul terrestrial and underwater communications links move up to Advanced Photonics. Nothing can be faster than light, but more important, no other medium can offer wider bandwidth when wave-multiplexing strategies are used. Photonics, employing dense wave division multiplexing (DWDM) can carry the equivalent of 12,000 encyclopedias or 5-million phone calls on a single fiber. Recent advances in photonics hardware, including higher-powered lasers, more efficient amplifiers and cleaner optical fiber are enabling incredible bandwidth for the Internet and general communications services. But how do we route a light beam? The long-haul segments of the Internet, now mostly fiberoptics, have been converting modulated light to electronic signals, routing with conventional electronic hardware and then re-converting back to light. Yes, O-E-O (Opto-electro-opto) works, but with cost and time-delay penalties. The communications industry has decreed that the double conversion process must go, but what technology will be the replacement? Enter optical MEMS, or MOEMS (micro-opto-electro-mechanical systems). The MOEMS switch/router approach was endorsed by the Internet carrier and hardware industry that paid billions of dollars in 2000 to acquire MEMS companies, some that had not even shipped a product. But what are the issues and are there competing technologies that could win? Micro-mirror technology is at the top of the popularity chart right now. Can MOEMS mirror routers solve cost problems and can they even switch at the rates demanded. What is the ideal mirror switch strategy: binary “off/on” or point-to-light pipe arrays? What about other MEMS approaches such as micro-bubble fluid beam refraction that appears to offer a much simpler construction? Maybe the mechanical devices are only an interim destined to obsolescence by a future solid state optics switch. The optical switch, powered totally by photons, is already in the lab and could be the final answer. This paper will survey MOEMS inside the Internet to seek answers to the billion dollar questions. The focus will be on micro-mirrors and their packaging issues both inside and out. We will deal with selecting the ideal optical MEMS package and choosing the right atmosphere control. Certain in-package contaminants are death to mirrors, but they can be controlled even if generated after the package is sealed. So tune in to find out if MEMS can catch the WAVE!

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