Optimal H2 - IMC based PID Controller Design for Multivariable Unstable Processes

Dasari, Purushottama Rao; Raviteja, K. V. N. S.; Rao, A. Seshagiri

doi:10.1016/j.ifacol.2016.03.124

Cited by 11 publications

(6 citation statements)

References 6 publications

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“…Performance of the designed controller is much better than that of the previously existing methods. Even though interactions are slightly more in some cases for the proposed design, on a whole, the proposed designed controller acts better than both Hazarika and Chidambaram [12] method and Dasari et al [11] method. Proposed control system is showing improved responses in the case of set point tracking and disturbance rejection.…”

Section: Discussionmentioning

confidence: 88%

“…The ability to provide good stable closed loop response even when there are large amount of perturbations in the process parameters is a major advantage of the proposed method over previously existing methods. Quantitative comparison is carried out using IAE values and the proposed method is superior over Hazarika and Chidambaram [12] method and Dasari et al [11] method.…”

Section: Discussionmentioning

confidence: 99%

“…The controllers for all methods are given in Table 2. The closed loop responses are plotted for a unit step change in the set point and disturbance separately and are compared with other methods such as Hazarika and Chidambaram [12] and Dasari et al [11]. Fig.…”

Section: ⎥ ⎥ ⎥mentioning

confidence: 99%

“…Rajapandiyan et al [10] designed a controller for multi loop stable processes based on ETF (equivalent transfer function) approximation with simplified decouplers. Recently, Dasari et al [11] used ETF to design the controllers based on optimal H2 IMC principles, simplified decouplers are also included and observed enhanced performance for unstable systems. Hazarika and Chidambaram [12] proposed a double loop control structure to decrease the overshoot such as proportional controller followed by PI controller in the outer loop based on the equivalent transfer function.…”

Section: Introductionmentioning

confidence: 99%

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Improved controller design for two-input-two-output (TITO) unstable processes

Rao¹,

Raviteja²,

Dasari³

2016

REFFIT

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Controller design for unstable processes is relatively difficult when compared to stable processes. The complexity increases further formultivariable unstable processes. In this work, simplified tuning rules are proposed to design PID controller for unstable multivariable processes.Decouplers are applied to make the loops independent and diagonal elements of equivalent transfer function are used to design controllers. For this,the decoupler design procedure proposed by Hazarika and Chidambaram [10] is used. Two theoretical examples of TITO unstable processes withtime delays are considered for simulation. Comparative analysis has been carried out with the recently reported methods in the literature andobserved that the proposed method provides improved closed loop performances. Robustness studies are also carried out with various perturbationsin the processes.

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Section: Discussionmentioning

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Section: ⎥ ⎥ ⎥mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Improved controller design for two-input-two-output (TITO) unstable processes

Rao¹,

Raviteja²,

Dasari³

2016

REFFIT

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“…This method can decouple and tune the system performance in spite of exceptional unstable processes but is dependent on the precision of controlled models in the system. Since the IMC structure bears a great similarity with Smith control, an optimal H2 PID controller 26 is designed in line with the IMC principle for unstable processes with right half plane (RHP) zero poles and time delays, whose PID parameters 27 are accessed by Maclaurin series approximation or stability controller parameters 28 accessed in the Blaschke product method; moreover, the controller's closed-loop control performance of unstable processes with time delays is enhanced in conjunction with rules for adjustment of maximum sensitivity tuning parameters. In Humaidi and Hasan, 29 2 two-degree-of-freedom control strategy is combined with sliding mode control.…”

Section: Introductionmentioning

confidence: 99%

Design of modified 2-degree-of-freedom proportional–integral–derivative controller for unstable processes

Zhang

Zou

et al. 2020

Measurement and Control

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Concerning first-order unstable processes with time delays that are typical in chemical processes, a modified 2-degree-of-freedom proportional–integral–derivative control method is put forward. The system presents a two-loop structure: inner loop and outer loop. The inner loop is in a classical feedback control structure with a proportional controller intended for implementing stable control of the unstable process; the outer loop is in a 2-degree-of-freedom structure with feedforward control of set points, where the system’s tracking response of set points is separated from its disturbance response. To be specific, the system has a feedforward controller that is designed based on the controlled object models and mainly used for regulating the system’s set point tracking characteristics; besides, it has a feedback controller that is designed on the ground of direct synthesis of disturbance suppression characteristics to improve the system’s disturbance rejection. To verify the effectiveness, the system is put into a theoretical analysis and simulated comparison with other methods. Simulation results show that the system has good set point tracking characteristics and disturbance suppression characteristics.

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