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Adaptive Controllers in Practice - Part Two (Digest No: 1996/060), IEE Colloquium on

Date 13 Mar 1996

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Displaying Results 1 - 9 of 9
  • Genetic-based pole-placement for self-tuning PID

    Publication Year: 1996 , Page(s): 3/1 - 3/3
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (184 KB)  

    The design of pole-assignment self-tuning adaptive control is far from straightforward; the proper placement of poles is mostly done on a trial and error basis at least in the Z-domain. In this paper, a design scheme based on genetic algorithms is proposed. Genetic algorithms are used to find pole-locations globally over the unit circle View full abstract»

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  • Adaptive inferential control

    Publication Year: 1996 , Page(s): 9/1 - 9/3
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (324 KB)  

    Despite the successful application of advanced predictive control algorithms to many industrial chemical processes satisfactory system performance cannot always be guaranteed. This is often the case where the infrequent measurement of key process outputs is unavoidable due to sampling limitations. In such situations the ability to detect deviations from desired process behaviour is significantly impaired. Inferential estimation techniques employ more easily measured secondary variables to infer the desired primary variable. This facilitates the early detection of disturbances thus improved control performance is to be expected. An adaptive inferential measurement algorithm has been successfully applied to various industrial processes (Lant et al., 1991; Mitchell et al., 1995). This contribution discusses the development of a model based control strategy using the inferential estimation algorithm as a basis. The theoretical development of the adaptive inferential long range predictive control algorithm is outlined. The algorithm offers enhanced control performance when compared to existing model based design strategies View full abstract»

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  • Comparison of bilinear and PID control on a test furnace at British Steel

    Publication Year: 1996 , Page(s): 5/1 - 5/5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (400 KB)  

    This paper details the findings of a comparative study when a single-input single-output bilinear self-tuning controller, which has been developed by the Control Theory and Applications Centre of Coventry University, is applied to a re-heat furnace at British Steel, Swinden Technology Centre, Moorgate, Rotherham. The performance of the bilinear self-tuner is compared to that of an industry standard PID controller which had been previously tuned manually to achieve optimum performance. Whilst the performances of the two schemes are not dissimilar the bilinear approach with its online tuning facilities offers potential advantages over existing commercially available automatic loop tuning devices It is recommended that the bilinear controller should be further developed and extensively evaluated under demonstrator and real-time plant trials on continuously operated furnaces View full abstract»

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  • A fuzzy logic model, reference adaptive controller

    Publication Year: 1996 , Page(s): 6/1 - 6/6
    Cited by:  Papers (4)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (420 KB)  

    The purpose of this paper is to address the issue of tuning the adaptation gains of MRAC systems using fuzzy logic technique to result in a fuzzy logic model reference adaptive control (FLMRAC) systems. The technique is implemented and applied to control a vehicle suspension system under severe operating conditions. Results show both good ride and handling performance as required in vehicles View full abstract»

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  • A framework for the implementation of self-tuning/adaptive control at potable water treatment works

    Publication Year: 1996 , Page(s): 7/1 - 7/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (496 KB)  

    This paper concerns the development of an interactive control scheme that applies self-tuning/adaptive control of simple PI and predictive PI controllers. There has been extensive interest in feedback control systems that automatically adjust their controller settings to compensate for changes in the process or the environment. Such systems are referred to as adaptive. The scheme described satisfies this basic definition but adaptation is not continuous. The algorithm consists of two basic operations. The first is based on continuous monitoring of the process performance and can be programmed to initiate a re-tune when the performance degrades to some pre-specified condition. The self-tuning strategy used, which incorporates a facility for time-delay compensation, will be outlined. The paper concludes with an example common to water treatment, namely the adjustment of the pH of the treated water View full abstract»

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  • Minimal controller synthesis for time-delay systems using a Smith predictor

    Publication Year: 1996 , Page(s): 4/1 - 4/5
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (240 KB)  

    Minimal controller synthesis (MCS), an extension of MRACS, cannot readily be applied to time-delay systems. The article shows its application to such a system, a steam/water heat exchanger, by use of a Smith predictor. The MCS structure used is robust to parameter variations and disturbances View full abstract»

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  • Adaptive control of turbo generator excitation

    Publication Year: 1996 , Page(s): 2/1 - 2/5
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (332 KB)  

    Concerns the implementation of the GPC self-tuning control on the excitation system of a turbo generator, taking into account several potential problems. The plant signals used for feedback are far from perfect. Although, robustness has received some consideration in self-tuning field, techniques most suitable for the control of excitation problem had to be identified and chosen for implementation. Problems such as unmodelled dynamics, disturbances, steady state offsets and nonlinearities have a considerable effect on the robustness and hence need attention during design. The popular assumption of a persistently exciting plant is generally not true. Hence ways to make the parameter estimator of the self-tuning controller handle those periods during which very little dynamic information about the plant is available, should be carefully considered. Many researchers have attempted to increase the range of applicability of linear self-tuner which include: use of variable forgetting factors for improved adaptivity while also reducing the possibilities of numerical instability; covariance resetting techniques for improved alertness, providing rapid adaptation. Other issues such as cautious least squares estimators, facilitating the input of an element of engineering knowledge, state variable techniques for smoother control via noise rejection and long prediction horizon of the system output have also received attention View full abstract»

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  • Disturbance attenuation in a hot strip rolling mill via feedforward adaptive control

    Publication Year: 1996 , Page(s): 1/1 - 1/4
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (316 KB)  

    Adaptive techniques are relatively common on modern rolling mills; most are aimed at improving overall means and are not well suited to dealing with individual disturbances. The disturbance issue is addressed in this paper by a feedforward control scheme which has yielded performance benefits on an operational mill View full abstract»

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  • IEE Colloquium on Adaptive Controllers in Practice - Part Two

    Publication Year: 1996
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (40 KB)  

    The following topics were dealt with: genetic pole-placement for PID; Smith predictor synthesis for delay systems; fuzzy MRAC; frequency estimation; adaptive inferential control; and applications to a hot strip rolling mill, turbogenerator excitation, a British Steel furnance, and potable water treatment View full abstract»

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