Showing papers in "Journal of Process Control in 2005"

TL;DR: In this article, the authors provide an overview of recent technological advances in the in situ control of pharmaceutical crystallization processes, and their relative merits are explained, as well as areas of future opportunities for application of advanced control strategies.

TL;DR: In this paper, a general form of feedback feed-forward iterative learning control (FFILC) is studied, comprising of two feedback controllers, a state feedback controller and a tracking error compensator, for the robustness and convergence along time direction, and an ILC for performance along the cycle direction.

TL;DR: In this article, an analytical two-degree-of-freedom control scheme for open-loop unstable processes with time delay is proposed, which leads to a remarkable improvement of regulatory capacity for both of reference input tracking and load disturbance rejection.

TL;DR: In this article, a fault detection and identification approach based on a multiblock partial least squares (MBPLS) method to monitor a complex chemical process and to model a key process quality variable simultaneously is discussed.

TL;DR: In this paper, particle filters based on the sequential Monte Carlo method are used for the estimation task, where a kernel smoothing approach is introduced for the robust estimation of unknown and time-varying model parameters.

TL;DR: A method that reduces the size of the required conditional probability data to one set is presented, which improves the computational efficiency without sacrificing detection and identification effectiveness.

TL;DR: In this article, the authors proposed a distance measure via the gap metric and applied it to a boiler-turbine unit to analyze its dynamics, and they showed that the unit shows severe nonlinearity, but the non-linearity can be avoided by careful choice of the operating range.

TL;DR: The variations of the NCO due to parametric uncertainty are studied and used to design appropriate adaptation laws and the directional influence of uncertainty is used to reduce the number of variables to adapt.

TL;DR: In this article, a closed-loop subspace identification approach through an orthogonal projection and subsequent singular value decomposition is proposed, which can simultaneously provide extended observability matrix, lower triangular block-Toeplitz matrix, and Kalman filtered state sequences.

TL;DR: A batch-to-batch model-based iterative optimal control strategy for batch processes is proposed, where a quadratic objective function is introduced to track the desired qualities at the end-point of a batch.

TL;DR: In this paper, a laboratory ball mill grinding circuit is simulated with detuned multi-loop PI controllers, unconstrained and constrained model predictive controllers, and their performances are compared.

TL;DR: In this article, a new dynamic loop pairing criterion for decentralized control of multivariable processes is presented, utilizing both steady state gain and bandwidth information of the process open loop transfer function elements, through defining an effective gain matrix, the loop pairing procedures of popular relative gain array method is directly extended to the new method which can reflect dynamic loop interactions under finite bandwidth control.

TL;DR: In this paper, a multivariate empirical model predictive control strategy (LV-MPC) for trajectory tracking and disturbance rejection for batch processes is presented based on dynamic principal component analysis (PCA) models of the batch process.

TL;DR: In this paper, a simple and new method for detecting valve stiction in an oscillating control loop is proposed based on the calculation of areas before and after the peak of the oscillating signal.

TL;DR: In this article, a methodology based on principal component analysis (PCA) is proposed to select the most suitable secondary process variables to be used as soft sensor inputs to estimate the product compositions for a simulated batch distillation process.

TL;DR: In this paper, a double two-degree-of-freedom control scheme is proposed for enhanced control of unstable delay processes, motivated by the modified Smith predictor control in [IEE Proc. Control Theory Appl. 16(5) (1999) 359] and devised to improve in the following ways: (i) one more freedom of control is introduced in their scheme to enable manipulation of disturbance transient response, and is tuned based on minimization of the integral squared error criterion; (ii) four controllers in the scheme are well placed to separately tune the denominators and numerators of

TL;DR: In this article, a PID controller is used to suppress slug flow by active use of the topside choke, which results in a reduction in slug flow in some km long flow lines along the seabed.

TL;DR: In this paper, a method for real-time classification of crystal polymorphic and morphological forms based on on-line imaging and image analysis is presented, based on experimental results of crystallisation in a batch reactor of (L )-glutamic acid that has two polymorphs, the prismatic alpha and needle-shaped beta forms.

TL;DR: In this paper, a modelling approach to control auxiliaries of a PEM Fuel Cell and the design of control laws is presented in a first step, a modeling approach is presented to control auxiliary fuel cells and two choppers are designed and controlled to deliver the power demand from the Fuel Cell itself and Storage Elements added.

TL;DR: In this paper, the effect of stiction in actuators on closed loop performance and the importance of techniques, to be incorporated in the monitoring system, for automatic detection of the onset of this phenomenon are discussed.

TL;DR: In this article, a sliding mode control system design methodology is proposed, which integrates an identified second-order plus dead-time (SOPDT) model, an optimal sliding surface and a delay-ahead predictor.

TL;DR: The robust estimation of the covariance or correlation matrix at each scale is obtained by the proposed approach so that accurate MSPCA models can be obtained for process monitoring purposes.

TL;DR: In this article, a nonlinear observer for the states of the multiphase flow that relies on topside measurements only, and applies it to estimate downhole pressure for feedback control is proposed.

TL;DR: The proposed suboptimal benchmark is achievable by a practical control provided that the system of interest is minimum phase and analysis expressions for the lower and upper bounds of the true multivariate minimum variance are derived.

TL;DR: In this article, the authors proposed a fault detection and isolation system for industrial processes using dynamic neural networks, which has a feed-forward multi-layer structure and dynamic characteristics are obtained by using dynamic neuron models.

TL;DR: In this article, a state observer (steady state Kalman filter) for a multivariable system with unknown time delays, which is subjected to unmeasured disturbances is proposed.

TL;DR: In this article, a systematic approach for auto-tuning of PI/PID controller is proposed, where a single run of the relay feedback experiment is carried out to characterize the dynamics including the type of damping behavior, the ultimate gain, and ultimate frequency.

TL;DR: In this paper, the authors investigated moving horizon state estimation (MHSE) within a bounded-error context for continuous-time systems, using interval Taylor expansions to reduce the pessimism due to interval arithmetic.

TL;DR: In this paper, the authors examined the control of pH processes based on the Wiener model construct (a dynamic linear element representing the mixing dynamics of the process in series with a static nonlinearity representing the titration curve).

TL;DR: Two alternative methods for batch process monitoring are investigated and compared to an existing one (the benchmark) and the performance is discussed by means of fault detection performance indices.