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Control Theory and Applications, IEE Proceedings D

Issue 6 • Date November 1983

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Displaying Results 1 - 14 of 14
  • Design of model reference systems using frequency-domain methods

    Publication Year: 1983 , Page(s): 273 - 280
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (788 KB)  

    A new design approach is proposed for multivariable model reference adaptive systems, making use of linear feedback on the error signal, with augmentation of the linear compensator by nonlinear adaptation laws only if the linear compensation is inadequate for the task at hand. The determination of the required linear compensation is considered, and a multivariable frequency-domain performance criterion is developed. This performance criterion is then related to other scalar frequency-domain performance criteria. A new design method is outlined using the direct Nyquist array, and is then illustrated by application to a 2-input/2-output multivariable system with parameter uncertainty. View full abstract»

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  • Autopilot for ship control. Part 1: Theoretical design

    Publication Year: 1983 , Page(s): 281 - 287
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (846 KB)  

    A self-tuning ship-autopilot design is presented that reconciles the conflicting demands of course keeping and of manoeuvring by using two modes of operation. During the course-keeping mode the performance criterion is formulated to minimise heading error, propulsion losses and rudder activity, while in the manoeuvring phase the concern is simply to minimise heading error. The system parameters are identified using recursive least-squares estimation to confer on the autopilot a high degree of adaptability, as illustrated in the simulation studies of part 2 of the paper. View full abstract»

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  • Autopilot for ship control. Part 2: Simulation studies

    Publication Year: 1983 , Page(s): 288 - 294
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (669 KB)  

    In part 1 of the paper a self-tuning ship-autopilot design was presented that reconciles the conflicting demands of course keeping and of manoeuvring by using two modes of operation. During the course-keeping mode the performance criterion is formulated to minimise heading error, propulsion losses and rudder activity, while in the manoeuvring phase the concern is simply to minimise heading error. The system parameters are identified using recursive least-squares estimation to confer on the autopilot a high degree of adaptability, as illustrated in the simulation studies in this paper. View full abstract»

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  • Discrete-time multivariable criterion for limit cycle predictions

    Publication Year: 1983 , Page(s): 295 - 299
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (577 KB)  

    Circulant matrices and their properties provide a new interpretation of limit-cycle phenomena in discrete-time nonlinear feedback systems. The present work extends the results of a recent paper in order to derive a multivariable circle type of criterion with a suitable Nyquist interpretation. View full abstract»

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  • Optimal control of linear systems with delays in state and control via Walsh functions

    Publication Year: 1983 , Page(s): 300 - 312
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1197 KB)  

    The paper presents a parameter-embedding approach to the optimal control of linear time-delay systems, and develops a simple computational algorithm via Walsh functions. The algorithm employs the concept of Walsh operational matrices for delay and advance. These operational matrices provide us with a means of numerically integrating differential equations with delayed and advanced arguments; a major task in the process of computing optimal controls for time-delay systems. An attractive feature of the present method is its ultimate simplicity and the resulting piecewise constant controls are convenient in practical implementation. View full abstract»

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  • Structurally fixed modes in decentralised systems. Part 1: Two control stations

    Publication Year: 1983 , Page(s): 313 - 321
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (941 KB)  

    By using a structural analysis based on a digraph representation, the conditions are examined for the existence of structural controllability and observability in decentralised control systems. These are related to the existence of structurally fixed modes in a system with two control stations. A generalisation to the case of N control stations is given in Part 2 of this paper. View full abstract»

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  • Structurally fixed modes in decentralised systems. Part 2: General case

    Publication Year: 1983 , Page(s): 322 - 327
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (509 KB)  

    The results obtained in Part 1 are extended to the general case of N control stations in a decentralised control system. A detailed example showing the application of the techniques is also given. View full abstract»

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  • Heat-pump control

    Publication Year: 1983 , Page(s): 328 - 332
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (516 KB)  

    An air-to-water heat pump has been designed to operate with a variable-speed compressor, an electrically driven motorised expansion valve and variable-input air mass flow rate; all of these are supported by a microcomputer-based control and instrumentation system. The paper develops the control algorithms which provide for independent control of the valve, compressor speed and air mass flow rate so that the refrigerant pressure across the evaporator can be maintained to ensure maximum heat transfer occurs in the evaporator. Experimental results demonstrate that the efficiency of the heat pump can be improved by the on-line control system. View full abstract»

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  • State reconstruction in low-sensitivity design of 3-dimensional systems

    Publication Year: 1983 , Page(s): 333 - 340
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (730 KB)  

    The problem to be studied in the paper refers to a general class of the linear time-invariant multivariable three-dimensional (3-D) systems using state feedback. For these types of systems, in order to give a quantitative formulation of the problem, the mathematical model is either assumed or derived. In either case there is always a discrepancy between the actual system and its mathematical model, and sensitivity plays an important role in assessing the behaviour of the system or its components under varying conditions. It is shown that using matrix-minimisation techniques we can derive a set of nonlinear matrix equations which constitute the necessary conditions that must be satisfied for an optimal low-sensitivity solution for a general class of (3-D) multivariable systems. The initial conditions of the system are assumed to be random processes with known mean and covariance matrix. View full abstract»

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  • Recursive self-tuning algorithm for adaptive Kalman filtering

    Publication Year: 1983 , Page(s): 341 - 344
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (417 KB)  

    A new recursive algorithm for adaptive Kalman filtering is proposed. The signal state-space model and its noise statistics are assumed to depend on an unknown parameter taking values in a subset [', '] of Rs. The parameter is estimated recursively using the gradient of the innovation sequence of the Kalman filter. The unknown parameter is replaced by its current estimate in the Kalman-filtering algorithm. The asymptotic properties of the adaptive Kalman filter are discussed. View full abstract»

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  • Optimal control of power system generators incorporating nonlinear state feedback

    Publication Year: 1983 , Page(s): 345 - 349
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (538 KB)  

    Linear and nonlinear optimal controllers have been designed for a seventh-order nonlinear model of a single machine power system through excitation and governor reference settings to improve the transient performance of the system and to satisfy stability and other soft constraints. It is shown that nonlinear controllers improve the performance of the system under large disturbances. It is also shown that acceptable system performance can be obtained with reduced number of feedback signals. View full abstract»

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  • Computer-aided design of feedback controllers for nonlinear systems with applications to control of a double-inverted pendulum

    Publication Year: 1983 , Page(s): 350 - 358
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (836 KB)  

    The paper shows how the design of feedback controllers for nonlinear systems such as a doubleinverted pendulum may be formulated as an optimisation problem with infinite dimensional constraints. A double-inverted pendulum is successfully stabilised at the upright position using a CAD package based on such an optimisation algorithm. View full abstract»

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  • Reciprocal transformations in balanced model-order reduction

    Publication Year: 1983 , Page(s): 359 - 362
    Save to Project icon | PDF file iconPDF (458 KB)  
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  • Factor division: a useful algorithm in model reduction

    Publication Year: 1983 , Page(s): 362 - 364
    Save to Project icon | PDF file iconPDF (260 KB)  
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