A new modelling and identification scheme for time-delay systems with experimental investigation: a relay feedback approach

Pandey, Saurabh; Majhi, Somanath; Ghorai, Prasenjit

doi:10.1080/00207721.2017.1290299

Cited by 8 publications

(5 citation statements)

References 27 publications

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“…Now three different scenarios of how to set numerator parameters of the model transfer function (45) or even eventually alter all the transfer function parameters based on relayexperiment data follow.…”

Section:  mentioning

confidence: 99%

“…Numerator/denominator parameters estimation using Nelder-Mead method via Autotune Variation Plus experiment By substituting (54) into (45), the 8-parameter model is ready to be identified, i.e., HETDM q is not fixed. We do let use the ATV+ technique (see "ATV+ technique") that dictates the use of three artificial delays yielding the estimation of three additional critical points in the frequency domain.…”

Section:  mentioning

confidence: 99%

“…Roughly speaking, this function is a linear approximation (usually based on the Fourier series expansion) of the nonlinear relay behavior. Second, the curve fitting approach attempts to fit the feedback response in the time domain based on an analytic formulation of the response [43][44][45][46] . As third, the frequency fitting does the same yet in the frequency domain, which corresponds to the seeking of multiple frequency points, besides the ultimate case [47][48][49] .…”

Section: Introductionmentioning

confidence: 99%

“…Most of the linear process models used in literature when applying some of the relay-based identification experiments include input-output delays within First-Order plus Dead Time (FOPDT) or Second-Order plus Dead Time SOPDT models, either stable 44,45,46,50,55,63,69,76 or unstable 43,44,51,[77][78][79][80][81] ones. The models are represented simply by a series of a delay-free loworder submodel and the delay element.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Root Loci Analysis of a Simple Quasi-Polynomial And Its Use For Relay-Based Parameter Identification of a Delayed Infinite-Dimensional Heat-Exchanger Process

Pekař

Song

Padhee

et al. 2021

Preprint

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The focus of this contribution is twofold. The first part aims at the rigorous and complete analysis of pole loci of a simple delayed model, the characteristic function of which is represented by a quasi-polynomial with a non-delay and a delay parameter. The derived spectrum constitutes an infinite set, making it a suitable and simple-enough representative of even high-order process dynamics. The second part intends to apply the simple infinite-dimensional model for relay-based parameter identification of a more complex model of a heating-cooling process with heat exchangers. Processes of this type and construction are widely used in industry. The identification procedure has two substantial steps. The first one adopts the simple model with a low computational effort using the saturated relay that provides a more accurate estimation than the standard on/off test. Then, this result is transformed to the estimation of the initial characteristic equation parameters of the complex infinite-dimensional heat-exchanger model using the exact dominant-pole-loci assignment. The benefit of this technique is that multiple model parameters can be estimated under a single relay test. The second step attempts to estimate the remaining model parameters by various numerical optimization techniques and also to enhance all model parameters via the Autotune Variation Plus relay experiment for comparison. Although the obtained unordinary time and frequency domain responses may yield satisfactory results for control tasks, the identified model parameters may not reflect the actual values of process physical quantities.

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Section:  mentioning

confidence: 99%

Section:  mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Root Loci Analysis of a Simple Quasi-Polynomial And Its Use For Relay-Based Parameter Identification of a Delayed Infinite-Dimensional Heat-Exchanger Process

Pekař

Song

Padhee

et al. 2021

Preprint

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show abstract

“…The majority of those can be classified based on the applied methodology in (i) open-loop techniques, using the step response data [3][4][5], and (Ii) closed-loop algorithms, which employ a relay feedback system to ensure an oscillatory response [6,7]. In the former, in order to derive the parameters of a SOPDT model, a step response experiment is performed in open loop, whereas in the latter, the key idea is to use a relay with or without hysteresis in a control loop to ensure an oscillatory system response [8].…”

Section: Introductionmentioning

confidence: 99%

Estimation of First Order Plus Dead Time and Second Order Plus Dead Time models from noisy step response data

Maxim

Keyser

2022

Asian Journal of Control

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Summary This paper proposes the estimation of first‐order‐plus‐dead‐time (FOPDT) and second‐order‐plus‐dead‐time (SOPDT) models from noisy step response data. The model parameters are estimated by computation of areas, which makes it robust in the presence of stochastic disturbances in the step response data. The efficiency of the methodology is extensively tested in various numerical examples as well as in real‐life experimental tests. The results—comparing our proposed estimation method with some other methods—suggest that the novel algorithm can be used with noisy step response data and adequately approximates high‐order systems. Moreover, it does not require any system identification expertise, making it readily accessible for the nonexperienced user in industrial practice. The method is successfully validated for overdamped, reasonably underdamped, as well as highly oscillatory processes, hence offering a comprehensive estimation method.

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Time delay and model parameter estimation for nonlinear system with simultaneous approach

Liu,

Chen

2024

Journal of Process Control

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A new modelling and identification scheme for time-delay systems with experimental investigation: a relay feedback approach

Cited by 8 publications

References 27 publications

Root Loci Analysis of a Simple Quasi-Polynomial And Its Use For Relay-Based Parameter Identification of a Delayed Infinite-Dimensional Heat-Exchanger Process

Root Loci Analysis of a Simple Quasi-Polynomial And Its Use For Relay-Based Parameter Identification of a Delayed Infinite-Dimensional Heat-Exchanger Process

Estimation of First Order Plus Dead Time and Second Order Plus Dead Time models from noisy step response data

Time delay and model parameter estimation for nonlinear system with simultaneous approach

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