scispace - formally typeset
Search or ask a question
Author

Cristina I. Muresan

Other affiliations: Core Laboratories
Bio: Cristina I. Muresan is an academic researcher from Technical University of Cluj-Napoca. The author has contributed to research in topics: PID controller & Control theory. The author has an hindex of 14, co-authored 122 publications receiving 1046 citations. Previous affiliations of Cristina I. Muresan include Core Laboratories.

Papers published on a yearly basis

Papers
More filters
Journal ArticleDOI
TL;DR: A direct universal (automatic) tuner for basic loop control in industrial applications that enables the user to have in the tuning structure the advantages of the derivative action, therefore much improving the potential of good performance in real life control applications.
Abstract: This paper introduces a direct universal (automatic) tuner for basic loop control in industrial applications. The direct feature refers to the fact that a first-hand model, such as a step response first-order plus dead time approximation, is not required. Instead, a point in the frequency domain and the corresponding slope of the loop frequency response is identified by single test suitable for industrial applications. The proposed method has been shown to overcome pitfalls found in other (automatic) tuning methods and has been validated in a wide range of common and exotic processes in simulation and experimental conditions. The method is very robust to noise, an important feature for real life industrial applications. Comparison is performed with other well-known methods, such as approximate M-constrained integral gain optimization (AMIGO) and Skogestad internal model controller (SIMC), which are indirect methods, i.e., they are based on a first-hand approximation of step response data. The results indicate great similarity between the results, whereas the direct method has the advantage of skipping this intermediate step of identification. The control structure is the most commonly used in industry, i.e., proportional-integral-derivative (PID) type. As the derivative action is often not used in industry due to its difficult choice, in the proposed method, we use a direct relation between the integral and derivative gains. This enables the user to have in the tuning structure the advantages of the derivative action, therefore much improving the potential of good performance in real life control applications.

12 citations

Journal ArticleDOI
05 Jul 2018-Robotics
TL;DR: A calibration approach of a manipulator robot controller using an auto-tuning technique based on a single sine test is employed to obtain the optimal parameters of the proportional–integral–derivative PID controller.

12 citations

Journal ArticleDOI
TL;DR: Fractional calculus represents the generalization of integration and differentiation to an arbitrary order and has been widely used in the control engineering field as discussed by the authors, where its use in control engineering has been gaining more and more popularity in both modeling and identification, as well as in controller tuning.
Abstract: Fractional calculus represents the generalization of integration and differentiation to an arbitrary order. Since the very first occurrence of fractional differentiation more than 300 years ago, fractional calculus and research related to its possible application have deserved ever-growing attention and interest. The research community has managed to bring forward ideas and concepts that justify the importance of fractional calculus for future engineering and science discoveries. What has begun as a means to describe abnormal behaviours in viscoelasticity or diffusion, power law phenomena, long range processes or fractal structures has spread to almost all engineering fields and applied sciences. Nowadays, its use in control engineering has been gaining more and more popularity in both modeling and identification, as well as in the controller tuning.

12 citations

Journal ArticleDOI
TL;DR: In this paper, two control strategies for multivariable processes are proposed that are based on a decentralised and a steady state decoupling approach, and the designed controllers are fractional order PIs.
Abstract: Two control strategies for multivariable processes are proposed that are based on a decentralised and a steady state decoupling approach. The designed controllers are fractional order PIs. The efficiency and robustness of the proposed strategies is tested and validated using a non-minimum phase process. Previous research for the same non-minimum phase process has proven that simple decentralised or decoupling techniques do not yield satisfactorily results and a multivariable IMC controller has been proposed as an alternative solution. The simulation results presented in this paper, as well as the experimental results, show that the proposed fractional order multivariable control strategies ensure an improved closed loop performance and disturbance rejection, as well as increased robustness to modelling uncertainties, as compared to traditional multivariable IMC controllers.

12 citations

Journal ArticleDOI
TL;DR: In this work, a biomedical application requiring robust control properties has been used to illustrate the potential of an autotuned method, referred to as the fractional order robust autotuner, which is an extension of a previously presented autotuning principle and produces controllers which are robust to system gain variations.

11 citations


Cited by
More filters
Journal ArticleDOI

[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

Book ChapterDOI
01 Jan 2015

3,828 citations

Journal ArticleDOI
TL;DR: This review investigates its progress since the first reported use of control systems, covering the fractional PID proposed by Podlubny in 1994, and is presenting a state-of-the-art fractionalpid controller, incorporating the latest contributions in this field.

447 citations

01 Jan 2016
TL;DR: Formulas for natural frequency and mode shape is available in the authors' book collection an online access to it is set as public so you can get it instantly.
Abstract: formulas for natural frequency and mode shape is available in our book collection an online access to it is set as public so you can get it instantly. Our book servers hosts in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the formulas for natural frequency and mode shape is universally compatible with any devices to read.

333 citations

Journal ArticleDOI
TL;DR: An aggregate model of EV fleets and improved version of fractional order (FO) controller is provided in all the areas for robust LFC considering bilateral transactions and Numerous simulations are conducted to validate the superiority of the proposed control strategy.
Abstract: Introduction of vehicle-to-grid technology offer electric vehicles (EVs) to participate in different ancillary services under competitive electric market. EVs provide an opportunity to grow new products and services for grid management. Particularly, EVs, which is a new form of distributed energy storage, can be used to compensate the uncontracted power in the local area if the contracts between the market players are violated. This paper presents the participation of EVs for load frequency control (LFC) under deregulated environment along with other conventional sources such as hydro, thermal, and gas turbine units. An aggregate model of EV fleets and improved version of fractional order (FO) controller is provided in all the areas for robust LFC considering bilateral transactions. Flower pollination algorithm, which is one of the new proven nature inspired algorithm employed to choose the optimal parameters of the FO controllers under several scenarios. Numerous simulations are conducted to validate the superiority of the proposed control strategy.

199 citations