The Experts below are selected from a list of 903 Experts worldwide ranked by ideXlab platform
Christos Georgakis - One of the best experts on this subject based on the ideXlab platform.
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A new measure of process output Controllability
Journal of Process Control, 2000Co-Authors: David R. Vinson, Christos GeorgakisAbstract:Abstract A steady state, multivariable, and nonlinear measure is presented for assessing the input–output, open-loop Controllability of a process. This measure ascertains the Inherent Controllability of the process, as it is calculated in the absence of any regulatory control structure. For the process examples utilized in this paper, it is also independent of the inventory control structure that might be assumed present in order to keep the inventory levels constant. This measure evaluates the ability of a design to reach all points of the desired output space and to reject the expected disturbances utilizing input action not exceeding the available input space. Besides being applicable to a SISO (Single Input, Signal Output) case, its multivariable character is shown to be more appropriate than existing measures such as RGA (Relative Gain Array), minimum singular value, and condition number.
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A New Measure of Process Output Controllability
IFAC Proceedings Volumes, 1998Co-Authors: David R. Vinson, Christos GeorgakisAbstract:Abstract A steady state, multivariable, and nonlinear measure is presented for assessing the input-output, open-loop Controllability of a process. This measure is ascertaining the Inherent Controllability of the process, as it is calculated in the absence of any regulatory control structure. It is also independent of the inventory control structure that might be assumed present in order to keep the inventory levels constant. This measure evaluates the ability of a design to reach all points of the desired output space and to reject the expected disturbances utilizing input action not exceeding the available input space. Besides being applicable to a SISO case, its multivariable character is shown to be more accurate than existing measures such as RGA, minimum singular value, and condition number.
David R. Vinson - One of the best experts on this subject based on the ideXlab platform.
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A new measure of process output Controllability
Journal of Process Control, 2000Co-Authors: David R. Vinson, Christos GeorgakisAbstract:Abstract A steady state, multivariable, and nonlinear measure is presented for assessing the input–output, open-loop Controllability of a process. This measure ascertains the Inherent Controllability of the process, as it is calculated in the absence of any regulatory control structure. For the process examples utilized in this paper, it is also independent of the inventory control structure that might be assumed present in order to keep the inventory levels constant. This measure evaluates the ability of a design to reach all points of the desired output space and to reject the expected disturbances utilizing input action not exceeding the available input space. Besides being applicable to a SISO (Single Input, Signal Output) case, its multivariable character is shown to be more appropriate than existing measures such as RGA (Relative Gain Array), minimum singular value, and condition number.
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A New Measure of Process Output Controllability
IFAC Proceedings Volumes, 1998Co-Authors: David R. Vinson, Christos GeorgakisAbstract:Abstract A steady state, multivariable, and nonlinear measure is presented for assessing the input-output, open-loop Controllability of a process. This measure is ascertaining the Inherent Controllability of the process, as it is calculated in the absence of any regulatory control structure. It is also independent of the inventory control structure that might be assumed present in order to keep the inventory levels constant. This measure evaluates the ability of a design to reach all points of the desired output space and to reject the expected disturbances utilizing input action not exceeding the available input space. Besides being applicable to a SISO case, its multivariable character is shown to be more accurate than existing measures such as RGA, minimum singular value, and condition number.
Tahir I. Malik - One of the best experts on this subject based on the ideXlab platform.
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A software package for process Controllability analysis
Computers & Chemical Engineering, 1992Co-Authors: Saeed Fararooy, John D. Perkins, Tahir I. MalikAbstract:Abstract The scope of the paper relates to the introduction of the concepts and functionality of Controllability analysis for chemical processes ( Perkins, 1989 ) and the development of a user friendly software package, to be referred to as the Process Controllability Tool Box (PCTB). Process and control engineers in industry may use PCTB to assess plant design alternatives on the basis of their Controllability. Alternatively, this can be achieved using dynamic simulation techniques, but with two disadvantages. First, dynamic simulation of a wide range of scenarios is very time consuming and secondly closed loop simulation would require models of actuators and measurement instruments as well as the need for control system structure and parameter tuning to be fully developed for each design option. Whilst there is little doubt that such simulations should be performed to verify the final design, there is a need for a less elaborate technique to aid the process engineer in screening alternatives at an earlier stage in the design process. The PCTB quantifies the Inherent Controllability characteristics of the plant alternatives on the basis of their mathematical model and provides insight to be used in choosing the best design.
M. W. Smith - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Ship Inherent Controllability on Piloted Performance: Evaluation and Prediction
1991Co-Authors: J. Mazurkiewicz, M. W. SmithAbstract:This report describes the development of statistical formulas relating ship Controllability indices to measures of piloted performance. These formulae contribute to a methodology for the evaluation or prediction of risk in a waterway from the characteristics of user traffic. During this experiment, 7 commercial ships, ranging in size from 33,000 to 250,000 deadweight tons made multiple runs through narrow channels under comparable conditions. The application of new procedures to the Coast Guard's waterway design process is discussed.
Warren D. Seider - One of the best experts on this subject based on the ideXlab platform.
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Coordinated design and control optimization of nonlinear processes
Computers & Chemical Engineering, 1992Co-Authors: David D. Brengel, Warren D. SeiderAbstract:Abstract On a small time-scale, disturbances to a process can lead to off-spec production, decreased profitability and the violation of hard process constraints, creating unsafe conditions. A strategy is presented for the design of processes that are operationally optimal, as well as steady-state optimal, and that operate prudently far from hard constraints. In addition to the evaluation of an economic objective, each potential design is evaluated for its Controllability, using the closed-loop response to several disturbances, simulated with model predictive control (MPC) algorithms. These algorithms provide excellent responses to unmeasured disturbances, allow for the inclusion of constraints and are fairly insensitive to the tuning parameters, allowing for an evaluation of the Inherent Controllability of a process. This strategy has been applied to a fermentation process with complex chemical and physical interactions and characterized by hysteresis and periodic behavior for some ranges of its design parameters. A simple optimization of venture profit leads to a design that is highly constrained and unstable. Using the above strategy, it is demonstrated that alternative designs exist with improved Controllability, but without retreating from the design constraints. This is counterintuitive and contrary to the results of several case studies. Furthermore, the design remains unstable.