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On-line correction of process temperature deviations in continuous retorts

JOURNAL OF FOOD ENGINEERING 2008年第2期84卷 258-269页

作者： Chen, Guibing Campanella, Osvaldo H. Corvalan, Carlos M. Haley, Timothy A. Purdue Univ Dept Agr & Biol Engn W Lafayette IN 47907 USA Purdue Univ Dept Food Sci W Lafayette IN 47907 USA Bush Brothers & Co Knoxville TN 37909 USA

Two algorithms. the fixed point (FP) and the worst case (WC), were developed for correcting on-line process temperature deviations in continuous retort operations through the adjustment of the product residence time, which could be performed by changing either the conveyor speed in hydrostatic retorts or the rotation speed in rotary retorts. After a process temperature deviation occurs, the FP algorithm consists in the selection of a point, for convenience close to the retort steam chamber exit, where process sterility is calculated, so that the product residence time can be changed accordingly. Alternatively, the WC algorithm consists in identifying the worst case, i.e. the more affected, container, for determining a conservative product residence time. Computer simulations showed that both algorithms provided fast estimations of the effect of process deviations on the product temperature and process lethality. This shows the potential of these algorithms for thermal processing industrial applications that may require on line control. (C) 2007 Elsevier Ltd. All rights reserved.

关键词： continuous retorts process temperature deviations on-line correction control algorithms fixed point worst case

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Assessment of Despiking Methods for Turbulence Data in Micrometeorology

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JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY 2016年第9期33卷 2001-2013页

作者： Starkenburg, Derek Metzger, Stefan Fochesatto, Gilberto J. Alfieri, Joseph G. Gens, Rudiger Prakash, Anupma Cristobal, Jordi Univ Alaska Fairbanks Inst Geophys 903 Koyukuk Dr Fairbanks AK 99775 USA Univ Alaska Fairbanks Coll Nat Sci & Math Dept Atmospher Sci Fairbanks AK USA Univ Colorado Natl Ecol Observ Network Fundamental Instrument Unit Boulder CO 80309 USA Univ Colorado Inst Arctic & Alpine Res Boulder CO 80309 USA USDA ARS Hydrol & Remote Sensing Lab Beltsville MD USA

The computation of turbulent fluxes of heat, momentum, and greenhouse gases requires measurements taken at high sampling frequencies. An important step in this process involves the detection and removal of sudden, short-lived variations that do not represent physical processes and that contaminate the data (i.e., spikes). The objective of this study is to assess the performance of several noteworthy despiking methodologies in order to provide a benchmark assessment and to provide a recommendation that is most applicable to high-frequency micrometeorological data in terms of efficiency and simplicity. The performance of a statistical time window-based algorithm widely used in micrometeorology is compared to three other methodologies (phase space, wavelet based, and median filter). These algorithms are first applied to a synthetic signal (a clean reference version and then one with spikes) in order to assess general performance. Afterward, testing is done on a time series of actual CO2 concentrations that contains extreme systematic spikes every hour owing to instrument interference, as well as several smaller random spike points. The study finds that the median filter and wavelet threshold methods are most reliable, and that their performance by far exceeds statistical time window-based methodologies that use the median or arithmetic mean operator (-34% and -71% reduced root-mean-square deviation, respectively). Overall, the median filter is recommended, as it is most easily automatable for a variety of micrometeorological data types, including data with missing points and low-frequency coherent turbulence.

关键词： Methods Quality control Software Automation Studies Turbulence control algorithms Science education Observatories Datasets

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Effects of synchronous vibration of bearing on stability of externally pressurized air journal bearings

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JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME 1999年第4期121卷 830-835页

作者： Lee, JB Kim, KW Samsung Elect Co Ltd Suwon 442742 Kyonggi Do South Korea Korea Adv Inst Sci & Technol Dept Mech Engn Taejon 305701 South Korea

An active control of bearing is proposed as a new method to improve the stability characteristics of the externally pressurized nir journal bearing and the results of numerical investigations of the stability characteristics of the actively controlled air journal bearing are presented. The synchronous control, where the bearing center whirls with the same frequency as the journal center with respect to the position in the steady state, is proposed as a control algorithm of the active air bearing. The step jump method is used to calculate the locus of the journal center which whirls or vibrates relative to the whirling bearing. The stability characteristics of the high speed rotor supported by actively controlled bearing system for zero steady-state eccentricity are investigated for various phase difference between the bearing and journal. It is shown that the stability of the air bearing can be greatly increased by the controlled synchronous motion of the bearing, and there is an optimum phase difference, which gives the maximum stability limit of the system.

关键词： Bearings Stability Rotors control algorithms Air bearings Whirls Steady state Vibration Journal bearings

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Energy and visual comfort performance of electrochromic windows with overhangs

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BUILDING AND ENVIRONMENT 2007年第6期42卷 2439-2449页

作者： Lee, E. S. Tavil, A. Lawrence Berkeley Lab Environm Energy Technol Div Bldg Technol Program Berkeley CA 94720 USA Istanbul Tech Univ Fac Architecture TR-34437 Istanbul Turkey

DOE-2 building energy simulations were conducted to determine if there were practical architectural and control strategy solutions that would enable electrochromic (EC) windows to significantly improve Visual comfort without eroding energy-efficiency benefits. EC windows were combined with overhangs since opaque overhangs provide protection from direct sun which EC windows are unable to do alone. The window wall was divided into an upper and lower aperture so that various combinations of overhang position and control strategies could be considered. The overhang was positioned either at the top of the upper window aperture or between the upper and lower apertures. Overhang depth was varied. EC control strategies were fully bleached at all times, modulated based on incident vertical solar radiation limits, or modulated to meet the design work plane illuminance with daylight. The EC performance was compared to a state-of-the-art spectrally selective low-e window with the same divided window wall, window size, and overhang as the EC configuration. The reference window was also combined with an interior shade which was manually deployed to control glare and direct sun. Both systems had the same daylighting control system to dim the electric lighting. Results were given for south-facing private offices in a typical commercial building. In hot and cold climates such as Houston and Chicago, EC windows with overhangs can significantly reduce the average annual daylight glare index (DGI) and deliver significant annual energy use savings if the window area is large. Total primary annual energy use was increased by 2-5% for moderate-area windows in either climate but decreased by 10% in Chicago and 5% in Houston for large-area windows. Peak electric demand can be reduced by 7-8%) for rnoderate-area windows and by 14-16% for large-area windows in either climate. Energy and peak demand reductions can be significantly greater if the reference case does not have exterior shading or

关键词： building simulation energy efficiency electrochromic windows daylighting control algorithms

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"Big Data Assimilation" Revolutionizing Severe Weather Prediction

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BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY 2016年第8期97卷 1347-+页

作者： Miyoshi, Takemasa Kunii, Masaru Ruiz, Juan Lien, Guo-Yuan Satoh, Shinsuke Ushio, Tomoo Bessho, Kotaro Seko, Hiromu Tomita, Hirofumi Ishikawa, Yutaka RIKEN Adv Inst Computat Sci Kobe Hyogo Japan Univ Maryland Dept Atmospher & Ocean Sci College Pk MD 20742 USA Japan Agcy Marine Earth Sci & Technol Applicat Lab Yokohama Kanagawa Japan Meteorol Res Inst Tsukuba Ibaraki Japan Univ Buenos Aires CONICET CIMA Buenos Aires DF Argentina Natl Inst Informat & Commun Technol Koganei Tokyo Japan Osaka Univ Suita Osaka Japan Meteorol Satellite Ctr Kiyose Japan

Sudden local severe weather is a threat, and we explore what the highest-end supercomputing and sensing technologies can do to address this challenge. Here we show that using the Japanese flagship "K" supercomputer, we can synergistically integrate "big simulations" of 100 parallel simulations of a convective weather system at 100-m, grid spacing and "big data" from the next-generation phased array weather radar that produces a high-resolution 3-dimensional rain distribution every 30 s two orders of magnitude more data than the currently used parabolic-antenna radar. This "big data assimilation" system refreshes 30-min forecasts every 30 s, 120 times more rapidly than the typical hourly updated systems operated at the world's weather prediction centers. A real high-impact weather case study shows encouraging results of the 30-s-update big data assimilation system.

关键词： Weather forecasting Meteorological satellites Velocity Quality control Studies System theory control algorithms Big Data

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Demand response algorithms for smart-grid ready residential buildings using machine learning models

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APPLIED ENERGY 2019年 239卷 1265-1282页

作者： Pallonetto, Fabiano De Rosa, Mattia Milano, Federico Finn, Donal P. Univ Coll Dublin UCD Energy Inst Dublin Ireland Univ Coll Dublin Sch Elect Engn Dublin Ireland Univ Coll Dublin Sch Mech & Mat Engn Dublin Ireland

This paper assesses the performance of control algorithms for the implementation of demand response strategies in the residential sector. A typical house, representing the most common building category in Ireland, was fully instrumented and utilised as a test-bed. A calibrated building simulation model was developed and used to assess the effectiveness of demand response strategies under different time-of-use electricity tariffs in conjunction with zone thermal control. Two demand response algorithms, one based on a rule-based approach, the other based on a predictive-based (machine learning) approach, were deployed for control of an integrated heat pump and thermal storage system. The two algorithms were evaluated using a common demand response price scheme. Compared to a baseline reference scenario, the following reductions were observed: electricity end-use expenditure (20.5% rule-based and 41.8% predictive algorithm), utility generation cost (18.8% rule-based and 39% predictive algorithm), carbon emissions (20.8% rule-based and 37.9% predictive algorithm).

关键词： Building demand response Optimisation Machine learning control algorithms Smart grids Energy efficiency

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Study of Stability of Precise Tiled-grating Device

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STROJNISKI VESTNIK-JOURNAL OF MECHANICAL ENGINEERING 2015年第2期61卷 99-106页

作者： Liao Yunfei Zhou Yi Liu Youhai Zuo Dong Tan Bo Chongqing Univ Coll Mech Engn Chongqing 400044 Peoples R China

To satisfy the high-stability requirement of a tiled grating we have analyzed and optimized the stability of a newly designed precise tiled-grating device considering three aspects: structure design, transmission chain, and control algorithms. The main structure of the device is changed from a parallel-board structure to a new tetrahedral brace design, enhancing the overall vibration stability;during the analysis of the transmission chain, the adjustment accuracy and stability of the device were ensured by slowing the growth of the error transmission factor;and for the optimization analysis of the PID control algorithms, we adopted a latch compensation method to avoid the saturated loss and a four-point central difference method to avoid the disturbances, thus enhancing the stability control of the device. To test the stability of the device, an optical experiment with a reference spot was designed. The experimental results showed that over 380 s, the ambient excitation response was always within an acceptable range. The average deflections about the X axis and Y axis are 0.243 and 0.00146 mu rad, respectively, which satisfy the stability requirement.

关键词： tiled-grating compressor stability dynamic response tetrahedral transmission chain control algorithms

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A flexible and time-efficient schedule-based communication tool for integrated lighting and thermal simulations of spaces with controlled artificial lighting and complex fenestration systems

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JOURNAL OF BUILDING PERFORMANCE SIMULATION 2016年第4期9卷 382-396页

作者： Vera, Sergio Bustamante, Waldo Molina, German Uribe, Daniel Pontificia Univ Catolica Chile Dept Construct Engn & Management Sch Engn Av Vicuna Mackenna 4860 Santiago Chile Ctr Sustainable Urban Dev CEDEUS Santiago Chile Pontificia Univ Catolica Chile Sch Architecture El Comendador 1916 Santiago Chile

Complex Fenestration Systems (CFS) incorporate a non-specular layer within the window assembly (e.g. undulated and perforated screens). CFS are often incorporated to the building facade for improving building thermal and visual performance. Thermal-lighting simulations of spaces with CFS are carried out with different tools. However, an integrated lighting and thermal analysis is a complex task to be implemented at the design stage of buildings that incorporates CFS. This paper presents mkSchedule, a new Radiance-based tool that allows the flexible and time-efficient generation of a schedule for the CFS position and luminaries power fraction. The methodology incorporates the three-phase method and use scripts written in Lua programming language. The schedule can be used for detailed thermal-lighting simulations. This work presents the application of this methodology to an office space, showing that the methodology is flexible enough to set different CFS and luminaries' controls, providing annual schedule in short computing time.

关键词： integrated thermal and lighting simulations complex fenestration systems artificial lighting schedule control algorithms

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controlling 6-DOF Systems with Multiple Exciters

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SOUND AND VIBRATION 2013年第10期47卷 6-11页

作者： Ayres, Russell Underwood, Marcos A. Keller, Tony Spectral Dynam Inc San Jose CA USA

Many different multi-exciter configurations have been created to produce motion in six degrees-of-freedom (6-DOF) simultaneously. This article examines some of these configurations and gives examples of controlling one popular setup, using advanced MIMO (multiple-input and multiple-output) control. Several types of problems were encountered with each configuration, and possible causes and suggested remedies are presented.

关键词： control algorithms

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Targeted processor architectures for high-performance controller implementation

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control ENGINEERING PRACTICE 1998年第7期6卷 867-878页

作者： Jones, S Goodall, R Gooch, M Univ Loughborough Dept Elect & Elect Engn Loughborough LE11 3TU Leics England

The requirements for hardware implementation of complex linear time-invariant controllers are addressed. This includes the basic formulation of the equations and their associated numerical properties. Hardware architectures which are directly targeted to these formulations are designed, and their performance is compared with a conventional digital signal processor for a relatively high-end controller task. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.

关键词： control algorithms architectures arithmetic and logic units control applications hardware

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