Modeling and control of non-square MIMO system using relay feedback

Kalpana, D.; Thyagarajan, T.; Gokulraj, N.

doi:10.1016/j.isatra.2015.09.012

Cited by 17 publications

(9 citation statements)

References 12 publications

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“…The step-test-based identification was firstly illustrated by Wang et al (2000), but applicable with decouplers. A relay feedback technique and variances in the relay with the type of tests are shown in studies (Bajarangbali and Majhi, 2012;Berner et al, 2017aBerner et al, , 2017bKalpana et al, 2015;Mehta and Majhi, 2011;Nema and Padhy, 2015;Semino and Scali, 1998). The improved frequency-domain identification technique for MIMO processes was described first by Semino and Scali (1998), who utilized a two-step strategy.…”

Section: Introductionmentioning

confidence: 99%

“…A similar approach was used to revisit TITO processes (Bajarangbali and Majhi, 2012). Further, Kalpana et al (2015) developed an identification scheme for the non-square MIMO system using time-domain relay response expressions. The expressions were derived using the block-relative-gain method and were verified on the two-tank cylindrical system.…”

Section: Introductionmentioning

confidence: 99%

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A single-step identification strategy for the coupled TITO process using fractional calculus

Kothari

Mehta

Prasad

2021

Transactions of the Institute of Measurement and Control

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The reliable performance of a complete control system depends on accurate model information being used to represent each subsystem. The identification and modelling of multivariable systems are complex and challenging due to cross-coupling. Such a system may require multiple steps and decentralized testing to obtain full system models effectively. In this paper, a direct identification strategy is proposed for the coupled two-input two-output (TITO) system with measurable input–output signals. A well-known closed-loop relay test is utilized to generate a set of inputs–outputs data from a single run. Based on the collected data, four individual fractional-order transfer functions, two for main paths and two for cross-paths, are estimated from single-run test signals. The orthogonal series-based algebraic approach is adopted, namely the Haar wavelet operational matrix, to handle the fractional derivatives of the signal in a simple manner. A single-step strategy yields faster identification with accurate estimation. The simulation and experimental studies depict the efficiency and applicability of the proposed identification technique. The demonstrated results on the twin rotor multiple-input multiple-output (MIMO) system (TRMS) clearly reveal that the presented idea works well with the highly coupled system even in the presence of measurement noise.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A single-step identification strategy for the coupled TITO process using fractional calculus

Kothari

Mehta

Prasad

2021

Transactions of the Institute of Measurement and Control

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“…Mnasser and Bouani (2015) proposed the robust predictive controller for a class of multi-input–multi-output non-linear systems. Modeling and control of non-square systems using relay-feedback method were discussed by Kalpana et al (2015). Saidi et al (2019) studied the comparsion of internal model controller for non-square systems.…”

Section: Introductionmentioning

confidence: 99%

Time domain modeling and control of complex non-linear chemical processes using relay feedback test

Sujatha

Panda

2020

Transactions of the Institute of Measurement and Control

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This study analyzes with the technology of auto tuning using relay feedback test for non-square MIMO system through process modeling, identification, input-output pairing and control strategies. However, the control configuration selection based on conventional steady-state Relative Gain Array (RGA) matrix sometimes degrades the loop performance and it needs attention. This study also deals with the real challenges in time domain modeling and appropriate pairing of loops for non-linear chemical processes. The choice of input-output pairing for square system has been extended to non-linear chemical processes. This ensures the system’s stability by selecting an appropriate manipulated-controlled variable pairing in non-linear chemical processes and the same is also tested for benchmark of non-linear chemical processes. In this study, two types of non-square systems are considered: one is systems with excess input than output variables and the other is systems with excess output than input variables. Some benchmark non-linear chemical processes, such as processes with mild nonlinearity, moderate to high nonlinearity and highly nonlinearity, are also taken for this study. Three standard benchmark processes are used in analysis of nonlinear chemical processes, namely: (1) Continuous Stirred Tank Reactor (CSTR) process; (2) hydrogen-ion- concentration (pH) process and (3) distillation column and this procedure is illustrated via simulation of 3-by-2 and 2-by-3 non-linear chemical processes.

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“…Most commonly the processes were modelled as a pair of first-order integer transfer functions for TITO dynamics. Among these strategies, a relay feedback technique and variances in relay with type of tests are shown in studies (Bajarangbali & Majhi, 2012;Kalpana et al, 2015;Nema & Padhy, 2015;Padhy & Majhi, 2006;Semino & Scali, 1998). The improved identification for MIMO processes was described firstly in Semino and Scali (1998).…”

Section: Introductionmentioning

confidence: 99%

“…Same way, a TITO process was approximated using a critical gain and frequency of oscillations by Padhy and Majhi (2006) and further revisited in Bajarangbali and Majhi (2012). A non-square MIMO system was identified using time-domain relay response expressions in Kalpana et al (2015). A state-space based time domain strategy for TITO process was illustrated in Nema and Padhy (2015) to identify TITO FOPDT models.…”

Section: Introductionmentioning

confidence: 99%

Fractional-order two-input two-output process identification based on Haar operational matrix

Kothari

Mehta

2020

International Journal of Systems Science

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The identification of multi-input-multi-output process is always challenging due to significant loop interactions. This article proposes an identification technique for two-input-two-output processes with fractional order models via Haar wavelet feature. The presented technique can estimate independent four fractional single-pole time delay models without additional steps to decouple processes during identification. The method uses a well-known relay feedback test to produce the input-output data for measurements. Then, the Haar wavelet operational matrix based algebraic approach is utilised to identify the unknown process models with reduced complexity. Numerical analysis on various examples show the efficacy even in presence of noise and without additional filter or preprocessing of measured signals. The comparative study proves advantages of the presented approach.

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Modeling and control of non-square MIMO system using relay feedback

Cited by 17 publications

References 12 publications

A single-step identification strategy for the coupled TITO process using fractional calculus

A single-step identification strategy for the coupled TITO process using fractional calculus

Time domain modeling and control of complex non-linear chemical processes using relay feedback test

Fractional-order two-input two-output process identification based on Haar operational matrix

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