A multivariable closed-loop process may become unstable for small changes in steady-state gains if integral action is used. The results of this work show that the Relative Gain Array (RGA) is related quantitatively to...
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Simple conceptual or mathematical models have always been used in design of linear SISO processcontrollers. On the other hand the design of nonlinear or MIMO controllers has always been perceived as requiring a detai...
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Simple conceptual or mathematical models have always been used in design of linear SISO processcontrollers. On the other hand the design of nonlinear or MIMO controllers has always been perceived as requiring a detailed dynamic model. This communication aims to show that, the use of simple models, can drastically affect the design of such controllers by suggesting a design framework that centers around the extensive variable of the process instead of the intensive one that are usually measured.
A nonlinear feedback controller for chemical reaction dynamic systems is examined in which the control action is a function of the deviation of the reaction rate from steady state. The motivations for this controller ...
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A nonlinear feedback controller for chemical reaction dynamic systems is examined in which the control action is a function of the deviation of the reaction rate from steady state. The motivations for this controller are (i) the finding that the reaction rate sensitivity to composition and temperature deviations is closely associated with the slow or unstable dynamic modes for the reaction systems studied to date; (ii) the controller nonlinearity mirrors the principal process nonlinearity; and (iii) such a control law is intuitively meaningful. In this paper, we develop the controller and propose a nonlinear analysis method for an idealized model of the continuous stirred tank reactor.
The steady-state interaction measure of dual composition control schemes for binary distillation columns is examined under the assumptions of constant relative volatility and constant molar overflow. An exhaustive enu...
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The steady-state interaction measure of dual composition control schemes for binary distillation columns is examined under the assumptions of constant relative volatility and constant molar overflow. An exhaustive enumeration is made of the control schemes that use column flows or their ratios as manipulated variables and product compositions as the controlled variables. Using a redundancy criterion, it is shown that 34 classes of dual composition control schemes have independent values for the interaction measure. This number reduces to 17 when the feed is a saturated liquid or gas. For high purity columns, the interaction measure of the above 34 control schemes approaches the values for the (L, V), (D, V), and (L3) control schemes. In this case none of the control schemes has a desirable interaction measure.
作者：
DUNIETZ, ISHSU, JLCMCEACHERN, MTSTOCKING, JHSWARTZ, MATROMBLY, RMThe authors
Irwin S. Dunietz John L.C. Hsu Michael T. McEachern James H. Stocking Mark A. Swartz andRodney M. Tromblyare responsible for design and development of the Manufacturing Process Control System. Mr. Dunietz joined AT&T in 1980. He is a member of the technical staff in the Manufacturing Information Automation department at AT&T Engineering Research Center Princeton New Jersey. He received an A.B. in mathematics from Cornell University and an M.S.E. in computer science from Princeton University. Mr. Hsu who joined AT&T in 1970 is a department head in the Manufacturing Information Automation department at the Engineering Research Center. He received an M.S. in electrical engineering from the University of Missouri. Mr. McEachern joined AT&T in 1962 and is a supervisor in the 5ESS™ Line Unit Manufacturing department at AT&T Technologies in Oklahoma City Oklahoma. He is responsible for the manufacturing process control center in Oklahoma City which provides computerized support for all circuit pack manufacturing. Mr. Stocking who joined AT&T in 1975 is a supervisor in the Manufacturing Information Automation department at the Engineering Research Center. He received a B.S. in chemical engineering from Rensselaer Polytechnic Institute and a Ph.D. in chemical engineering from the University of California Berkeley. Mr. Swartz joined AT&T in 1980 and is a member of the technical staff in the Manufacturing Information Automation department at the Engineering Research Center. He received an A.B. in computer science from Cornell University and an M.S. in computer science from Rutgers—The State University. Mr. Trombly who joined AT&T in 19 78 is an assistant manager at the AT&T Merrimack Valley Works in Massachusetts. Previously he was a supervisor at the Engineering Research Center. He holds a B.S. in computers and systems engineering and an M.S.E.E. from Rensselaer Polytechnic Institute.
The central challenge of all manufacturing is making products to the right standards and delivering them at the right time. AT&T is upgrading its corporate and factory resource planning systems to improve control ...
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The central challenge of all manufacturing is making products to the right standards and delivering them at the right time. AT&T is upgrading its corporate and factory resource planning systems to improve control of day-to-day manufacturing. The Manufacturing processcontrol System (MPCS), developed at the AT&T Engineering researchcenter (ERC), provides this support. MPCS connects the shop floor with production scheduling, accounting, product data archive, and engineering support systems.
Maintaining adequate underway production of fresh water for potable and boilerfeed consumption her been a chronic problem for many Navy ships for decades. Although “energy free” low pressure auxiliary exhaust steam ...
Maintaining adequate underway production of fresh water for potable and boilerfeed consumption her been a chronic problem for many Navy ships for decades. Although “energy free” low pressure auxiliary exhaust steam is used in water production, a recent investigation ( Naval Engineers Journal , April 1976) concluded that a significant net energy cost is involved. This energy cost has become more significant due to 1) the rapid rise in fuel costs and 2) the reduction in available auxiliary exhaust steam as the Navy's Energy Conservation Program becomes implemented. Indeed, as the Navy's ships begin to increase their operating efficiency, the energy cost of fresh water will rice. Many ships exceed their water allocation of 30 gal/man-day by 10 to 20 gallons. A goal was set to demonstrate that potable water consumption can be reduced by 20 to 25 gal/mm-day without Impairing “Hotel” services by the use of water conserving approaches such as reduced-flow showers; a modified laundry procedure; installation of flow meters at key locations; and other techniques. This conservation was demonstrated successfully during extended underway periods in USS Saratoga (CV-60) and USS Jonas Ingram (DD-938). Fleet-wide implementation of these conservation approaches could save the Navy millions of dollars.
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