scholarly journals Anisochronic Internal Model Control Design

10.14311/482 ◽  
2003 ◽  
Vol 43 (5) ◽  
Author(s):  
T. Vyhlídal ◽  
P. Zítek
Keyword(s):  
System Dynamics ◽  
Internal Model ◽  
Closed Loop ◽  
Control Design ◽  
Internal Model Control ◽  
Loop System ◽  
Closed Loop System ◽  
First Order ◽  
Dominant Pole ◽  
Model Control

The features of internal model control (IMC) design based on the first order anisochronic model are investigated in this paper. The structure of the anisochronic model is chosen in order to fit both the dominant pole and the dominant zero of the system dynamics being approximated. Thanks to its fairly plain structure, the model is suitable for use in IMC design. However, use of the anisochronic model in IMC design may result in so-called neutral dynamics of the closed loop. This phenomenon is studied in this paper via analysing the spectra of the closed loop system.

Internal Model Control–Proportional Integral Derivative–Fractional-Order Filter Controllers Design for Unstable Delay Systems

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Kahina Titouche ◽  
Rachid Mansouri ◽  
Maamar Bettayeb ◽  
Ubaid M. Al-Saggaf
Keyword(s):  
Fractional Order ◽  
Internal Model ◽  
Closed Loop ◽  
Control Structure ◽  
Internal Model Control ◽  
Loop System ◽  
Proportional Integral Derivative ◽  
Closed Loop System ◽  
Proportional Integral ◽  
Model Control

An analytical design for proportional integral derivative (PID) controller cascaded with a fractional-order filter is proposed for first-order unstable processes with time delay. The design algorithm is based on the internal model control (IMC) paradigm. A two degrees-of-freedom (2DOF) control structure is used to improve the performance of the closed-loop system. In the 2DOF control structure, an integer order controller is used to stabilize the inner-loop, and a fractional-order controller for the stabilized system is employed to improve the performance of the closed-loop system. The Walton–Marshall's method, which is applicable to quasi-polynomials, is then used to establish the internal stability condition of the closed-loop system (the fractional part of the controller in particular) and to seek the set of stabilizing proportional (P) or proportional-derivative (PD) controller parameters.

scholarly journals 2DOF IMC and Smith-Predictor-Based Control for Stabilised Unstable First Order Time Delayed Plants

Mathematics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1064
Author(s):  
Mikulas Huba ◽  
Pavol Bistak ◽  
Damir Vrancic
Keyword(s):  
Internal Model ◽  
Closed Loop ◽  
Structural Instability ◽  
Internal Model Control ◽  
Smith Predictor ◽  
Unstable Systems ◽  
First Order ◽  
Long Run ◽  
Model Control ◽  
Two Degree Of Freedom

The article brings a brief revision of the two-degree-of-freedom (2-DoF) internal model control (IMC) and the 2-DoF Smith-Predictor-based (SP) control of unstable systems. It shows that the first important reason for distinguishing between these approaches is the limitations of the control action. However, it also reminds that, in addition to the seemingly lucrative dynamics of transients, the proposed approaches can conceal a tricky behavior with a structural instability, which may manifest itself only after a longer period of time. Instead, as one of possible reliable alternatives, two-step IMC and filtered Smith predictor (FSP) design are applied to unstable first-order time-delayed (UFOTD) systems. Firstly, the 2-DoF P controller yielding a double real dominant closed loop pole is applied. Only then the 2-DoF IMC or FSP controllers are designed, providing slightly slower, but more robust transients. These remain stable even in the long run, while also showing increased robustness.

Emulator-based control and internal model control: Complementary approaches to robust control design

Automatica ◽  
1996 ◽  
Vol 32 (8) ◽  
pp. 1223-1227 ◽  
Author(s):  
Peter J. Gawthrop ◽  
Richard W. Jones ◽  
Daniel G. Sbarbaro
Keyword(s):  
Robust Control ◽  
Internal Model ◽  
Control Design ◽  
Internal Model Control ◽  
Model Control ◽  
Robust Control Design

New filters for internal model control design

1994 ◽  
Vol 4 (6) ◽  
pp. 757-775 ◽  
Author(s):  
Marco Campi ◽  
Wee Sit Lee ◽  
Brian D. O. Anderson
Keyword(s):  
Internal Model ◽  
Control Design ◽  
Internal Model Control ◽  
Model Control

scholarly journals Stabilization of the Magnetic Levitation System

2021 ◽  
Vol 11 (21) ◽  
pp. 10369
Author(s):  
Štefan Chamraz ◽  
Mikuláš Huba ◽  
Katarína Žáková
Keyword(s):  
Closed Loop ◽  
Magnetic Levitation ◽  
Internal Model Control ◽  
Pass Filter ◽  
Low Pass Filter ◽  
First Order ◽  
Model Based ◽  
Model Control ◽  
Levitation System ◽  
Magnetic Levitation System

This paper contributes toward research on the control of the magnetic levitation plant, representing a typical nonlinear unstable system that can be controlled by various methods. This paper shows two various approaches to the solution of the controller design based on different closed loop requirements. Starting from a known unstable linear plant model—the first method is based on the two-step procedure. In the first step, the transfer function of the controlled system is modified to get a stable non-oscillatory system. In the next step, the required first-order dynamic is defined and a model-based PI controller is proposed. The closed loop time constant of this first-order model-based approach can then be used as a tuning parameter. The second set of methods is based on a simplified ultra-local linear approximation of the plant dynamics by the double-integrator plus dead-time (DIPDT) model. Similar to the first method, one possible solution is to stabilize the system by a PD controller combined with a low-pass filter. To eliminate the offset, the stabilized system is supplemented by a simple static feedforward, or by a controller proposed by means of an internal model control (IMC). Another possible approach is to apply for the DIPDT model directly a stabilizing PID controller. The considered solutions are compared to the magnetic levitation system, controlled via the MATLAB/Simulink environment. It is shown that, all three controllers, with integral action, yield much slower dynamics than the stabilizing PD control, which gives one motivation to look for alternative ways of steady-state error compensation, guaranteeing faster setpoint step responses.

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