Composite Control System Research Articles

Composite Interval Control Systems: Some Strong Kharitonov-Like Properties

The interval model plays an important role in parametric robust control. This paper deals with the strict positive realness of a class of composite interval control systems, and establishes a strong Kharitonov-like extreme point criterion. We also discuss the robust strict positive realness of the shifted interval plant-controller family, and improve some previous results in the literature. Furthermore, for the collection of Popov plots of an interval transfer function family, we prove that a large portion of its outer boundary comes from the sixteen Kharitonov transfer functions. Finally, we study the beta boundedness of interval systems. A strong Kharitonov-like vertex result is established, namely, that all members in the interval system family are beta bounded if and only if the sixteen Kharitonov critical vertices are beta bounded.

Dynamic control of a remotely operated vehicle using a neural network

The control of a remotely-operated underwater vehicle to maintain a prescribed depth in shallow water under irregular surface waves is realized through the application of the Robust Adaptive Neuro Controller, a composite control system incorporating—together with the conventional control algorithm—a neural network controller. This network bestows a learning capability on the system, allowing it to deal with unanticipated disturbances that would otherwise cause erroneous behavior of the vehicle. The effectiveness of this application is verified through mathematical simulation of a model vehicle's behavior, through experiment in a model basin, and through simulation of the behavior of an actual remotely operated vehicle in shallow water under irregular surface waves. Graphic data representing the learning process undergone by the neural network distinctly indicate the rising output from the network with the progression of learning, and the vehicle's depth variation traced in terms of the mean square error vividly show the diminution of deviation from the prescribed depth obtained with application of the neural network. Thus controlled to maintain constant depth, under-water vehicles with power supplied externally through a tether for propulsion and for heavy-duty operations should consolidate their advantage for such activities as maintenance of submarine structures and surveys in deep or hazardous water.

An intelligent composite system for statistical process control

Combining statistical process control, artificial neural networks and an expert system for the intelligent analysis and control of a plastic extruder facility is described. Statistical methodology is compared and contrasted to the exploratory neural network technique, which learns to relate and classify dependent production variables based on measurements taken on-line during the process. Integrating the neural network analysis into a composite control system using an expert system is presented.

Performance characteristics of a composite multivariate quality control system.

We present the results of an evaluation of the performance characteristics of a composite multivariate quality control (CMQC) system that incorporates quality control rules for univariate, multivariate, and correlation conditions. The CMQC system evaluated is designed to help analysts detect unacceptable trends and systematic error in one or more variables, unacceptable random error in one or more variables, and unacceptable changes in the correlation structure of any pair of variables. It is also designed to be tolerant of missing data, to allow analysts to reject as few as one or as many as all variables in a run, and to provide analysts with control statistics and graphics that logically relate to sources of analytical error. We show that the various components of the CMQC system have adequate statistical power to detect systematic errors, random errors, and correlation changes under the conditions likely to be encountered with multivariate analytical measurement systems: (1) a single variable with increased systematic or random error; (2) all variables or a subgroup of variables affected by a common problem that increases systematic or random error; and (3) missing data for one or more variables in a run. We also show that the power of the multivariate component of the CMQC system to detect systematic and random errors is higher than the power of an alternative multivariate test criterion.

Composite erosion control system for a high cut slope : Collotta, T; Heiniger, P; Paviani, A; Moretti, P C Proc 4th International Conference on Geotextiles, Geomembranes and Related Products, The Hague, 28 May–1 June 1990V1, P381–384. Publ Rotterdam: A A Balkema, 1990

Composite erosion control system for a high cut slope : Collotta, T; Heiniger, P; Paviani, A; Moretti, P C Proc 4th International Conference on Geotextiles, Geomembranes and Related Products, The Hague, 28 May–1 June 1990V1, P381–384. Publ Rotterdam: A A Balkema, 1990

Composite multivariate quality control using a system of univariate, bivariate, and multivariate quality control rules

We propose a composite multivariate quality control (CMQC) system to control simultaneously measured variables. This system is designed to detect unacceptable trends and systematic error in one or more variables, unacceptable random error in one or more variables, and unacceptable changes in the correlation structure in any pair of variables. It is also designed to be tolerant of missing data, to be capable of rejecting as few as one or as many as all variables in a run, and to provide the analyst with control statistics and graphics that logically relate to sources of analytical error. Quality control rules for univariate, multivariate, and correlation conditions are incorporated in the system, as are plots displaying CMQC statistic values and control limits for univariate, multivariate, and correlation parameters. We also discuss advantages of the CMQC over the T2 and principal component multivariate quality control methods. We demonstrate the CMQC procedure using data from a laboratory process in which 40 variables were measured during 40 characterization runs and 23 runs analyzing unknowns.

A systems approach to the implementation of JIT methodologies in Lucas Industries

Competitive modern manufacturing businesses must operate total materials flow control systems to ensure low stock levels and short lead times. When a variety of products is produced, to achieve just-in-time operation relevant to the overall business time-constants, composite control systems are needed within the factory, supported by matching supply processes and levelled output scheduling.

Composite matrix inverses and generalized Gershgorin sets

In computational matrix algebra, Gershgorin's Theorem [8] and Ostrowski's Theorem[14] play key roles in establishing regularity conditions for complexn×nmatrices. As a result of this importance as well as possible applications in other areas, several extensions of these results have been made (Kotelyanski[9], Ky Fan [5], Brauer[2], Nwokah[10]), for point set matrices. More recently, further extensions have been made to include regularity conditions for composite matrices (matrices partitioned into blocks) (Brenner [3], Van der Sluis[16], Feingold and Varga[6], Cook [4]). Cook's result was motivated by engineering applications but is rather restrictive since, like Feingold and Varga, it requires that the matrices under consideration be diagonally dominant. In this paper, the diagonal dominance condition is replaced by a more general condition (theH-matrix condition). Estimates for the diagonal blocks of block-partitioned matrix are then obtained. The results on inclusion regions for eigenvalues unifiex the previous results of Feingolg and Varga [6], kotelyanski [9], Brauer [2], and generalizes the earlier results of Nwokah [10], from point matrices to block-partitioned matrices. In a sense, these results complement those of brenner [3] Van der Sluis [16], but like those of Cook [4], have a more immediate direct application to control engineering in the area of computer-aided design of composite feedback control systems (Nwokah [12]), which will be briefly reviewed towards the end of the paper.

On the stability of linear composite systems with delays

It is shown that the stability of composite feedback control systems with delays both in the state and the input can be checked from the stabilities of the individual isolated subsystems, if the composite system matrix has a certain new structure called the GKK-structure; and if the numerators and denominators of the determinants of the overall system transfer matrix and of the isolated system transfer matrices contain some term of a certain expansion called the principal term. The GKK-structure includes diagonal dominance, the Hadamard (M-matrix) structure, and normality as special cases.

Control and Supervision of The Eurelios Solar Power Plant: Design Philosophy and Operation Experience

Operating a solar power plant with limited personnel employment, while providing an operation flexibility adequate to the necessary experimental work, requires a non trivial coordination of the different subsystems realizing the complex energetic conversion and the adoption of a composite automatic control system keeping the plant components at their stipulated operating conditions. The paper describes the basic concept and the practical organization of the control and supervision functions adopted for the central receiver solar powered plant built near Adrano (Sicily) in the frame of the Eurelios Project founded by EEC. In particular, results of an accurate simulation study and experience of the first months of real plant operation are taken into account when discussing the most significant aspects of operator-plant interaction for which quite peculiar solutions have to be devised to comply with the continuously varying (dynamic) plant operation.

Model for the optimal planning of structural flood control systems

A mixed integer programing approach is described in this paper for the planning and design of composite multiunit flood control systems. The model is intended to be a preliminary selection device permitting the planner to compare alternative configurations and determine roughly the optimal solution to a given flood control problem. Such a solution may then be used to establish the guidelines and specifications for the design of the individual components. The flexibility of the method enables a large number of alternatives to be considered simultaneously, even though they may be at different stages of planning. It also recognizes that optimal operation is a function of system design.

複合系の局所フィードバックによる準最適制御

複合系の局所フィードバックによる準最適制御

Control of unstable mechanical system Control of pendulum†

This paper relates to the design of a control system for a mechanical system which contains an unstable mode and to an experiment for demonstrating that the control theory may be applied to practical real systems. In this paper the object treated is the control of the pendulum-cart system, which has been studied by many control theorists and engineers as an inverted pendulum problem, and a composite control system is designed not only to stabilize the inverted pendulum but to swing the pendulum from the natural pendent position up to the inverted position, which is actually made. The experimental results are presented.

Control of Boilers Fired by Solid Fuels in Suspension

In this paper are discussed those characteristics of boiler design and performance which have favoured the parallel development of automatic control of boiler auxiliaries. Consideration is given to those temporary conditions which arise during periods of load change, and which, if not accurately estimated and followed by the necessary corrective action, may lead to over-regulation of firing rate or feed-water supply. Instruments are provided to determine and inform the operator of the necessary action to be taken, and manual remote-control eliminates the laborious duties of routine readjustments necessary to maintain efficiency. In this field automatic control has many advantages and is quicker and more accurate in response than the human operator. The theory of elementary forms of automatic control devices is dealt with simply, and the mechanical means, employing pneumatically operated devices, by which these theoretical requirements are met are described. Examples are given of the use of standard apparatus in building up a composite control system, and the more complicated installations of boilers fired by spreader stokers, pulverized fuel and cyclone furnaces are dealt with.