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Model Control (model + control)

Distribution by Scientific Domains

Engineering	75%

Selected Abstracts

Application of adaptive lattice filters to internal model control

INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 6 2008
G. Nikolakopoulos
Abstract An adaptive internal model control (IMC) framework is proposed in this article for infinite impulse response systems. The innovation in this study stems from the relaxed assumption that the controller needs to know a priori the system order. To bypass this restriction, a lattice filter identifies the system's order as well as its reflection coefficients. Within the IMC structure, a lattice-based controller is utilized in the forward path in cascade with a low-pass detuning filter. The controller self-configures its structure according to the estimated system order, while the filter's bandwidth increases as the identifier estimates more accurately the system dynamics. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Internal model control design for transition control

AICHE JOURNAL, Issue 2 2000
Min-Sen Chiu
The problem of controlling processes with a wide range of operating conditions is addressed. The process dynamics is represented by the weighted-sum of the linear model by using model validity functions. By treating the validity functions as uncertainties in the system, an internal model control (IMC) design strategy is developed for a particular class of nonlinear systems. Robust stability analysis under mixed time-varying and time-invariant uncertainties is presented. Simulation results confirm that the proposed IMC design method is indeed superior to its conventional counterpart. [source]

Optimal grade transition control for liquid-propylene polymerization reactor,

ASIAN JOURNAL OF CONTROL, Issue 3 2010
Mohammad Al-haj Ali
Abstract A nonlinear control system integrating an off-line optimizer and a nonlinear model-based controller is developed to perform optimal grade transition operations in a continuous pilot plant reactor. A simple black-box model is developed and used to determine optimal trajectories of inputs and outputs for a series of three polypropylene grades. The simplified model is also used to develop a nonlinear controller. This controller is similar to generic model control; however, the integral action is omitted and an on-line updating scheme is incorporated to update pre-specified model parameters using delayed process measurements. The time optimal inputs, which are calculated by the off-line optimizer, are introduced to the plant in a feedforward manner. At the same time, the deviations from the optimal output are corrected using the feedback nonlinear controller. The simulations on a complex mechanistic model of the process reveal that the nonlinear control scheme performs well for both set point tracking and disturbance rejection. This paper integrates well-known methodologies, such as the generic-model control algorithm, parameter update schemes, and off-line optimization, together to develop an applicable and robust control technique for continuous polymerization reactors. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]