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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
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Journal ArticleDOI
01 Jan 2020
TL;DR: The experimental results obtained with the two different experimental tuning methods under several operating conditions are compared, illustrating the superiority of the KC autotuner.
Abstract: The paper focuses on a novel PID (proportional integral derivative) autotuner based on a single experi-mental sine test. The Kiss Circle (KC) autotuner design and validation are targeted on a vertical take-off and landing platform which exhibits a highly oscillatory non-linear motion with time delay. An additional autotuner fit for time delay processes such as the well-known Ziegler-Nichols method is used to determine a PID controller for the Vertical Take-Off and Landing (VTOL) process. The experimental results obtained with the two different experimental tuning methods under several operating conditions are compared, illustrating the superiority of the KC autotuner.
Proceedings ArticleDOI
06 Dec 2022
TL;DR: In this article , a novel predictive control strategy is proposed to enable uncertainty minimization through knowledge infusion into the closed loop of anesthetic-hemodynamic interaction in a set of patients during general anesthesia.
Abstract: A novel control strategy is proposed to enable uncertainty minimization through knowledge infusion into the closed loop. The developed methodology aims the application of predictive control to regulate the complex anesthetic- hemodynamic (AH) interaction in a set of patients during general anesthesia. A special focus is given to solutions for minimizing the risk of instability arising from large uncertainty in the patient model dynamics. The paper explores the concept of digitalizing surgical actions as part of the natural mimicking strategy of actual anesthesiologists’ real-life decision-making process. The simulations supporting the claims use an AH simulator. A feasibility study for solutions in an actual constrained input-output variable set is performed. Results confirm that the feasibility is enhanced when minimizing uncertainty conditions, having important clinical relevance in multi-drug optimization.
Proceedings ArticleDOI
16 Nov 2022
TL;DR: In this article , an existing Ziegler-Nichols method for fractional order controllers is modified to yield optimal parameters, and the tuning rules and the optimization algorithm are simple, yet they lead to efficient fractional orders controllers.
Abstract: Industry requires simple, yet efficient tuning methods for controllers. One of these tuning methodologies is the popular Ziegler-Nichols approach that requires little information regarding the process and has some pre-definite tuning rules. Although intensive research has been done in non-integer order controllers and their advantages have been demonstrated, their complexity and tedious tuning kept them away from industrial acceptance. In this manuscript, an existing Ziegler-Nichols method for fractional order controllers is modified to yield optimal parameters. The tuning rules and the optimization algorithm are simple, yet they lead to efficient fractional orders controllers. Simulation results are included to validate the proposed method.
DOI
07 Oct 2021
TL;DR: In this article, an impedance-based fractional order model was proposed to describe the dynamics of pain assessment based on experimental data, which is validated on real-life data and validated on the real life data.
Abstract: The present study presents the development of an impedance based fractional order model that describe the dynamics of pain assessment based on experimental data. Bioimpedance spectroscopy is used to acquire real-life electrodermal responses from a healthy subject undergoing induced acute pain. The measurements register both normal epidermal values in the absence of pain and bioimpedance measurements at the presence of sudden, acute, pain. The aim is to develop a general model that describes the feeling of pain in the presence/absence of active stimulus. The complex dynamics of the acquired data suggest the usage of fractional calculus, a powerful tool that provides a versatile and efficient solution of modeling complex physical phenomena. The proposed models are obtained using constrained optimization routines and are successfully validated on the real life data.
Proceedings ArticleDOI
04 May 2022
TL;DR: In this article , a comparison between three PID-type controllers designed via different methods for a process with time-varying properties is presented, and an analysis of the system properties reveals the opportunity to operate in closed loop in a self-tuning manner, which avoids the necessity to re-design the controller parameter values.
Abstract: In this work, we present a comparison between three PID-type controllers designed via different methods for a process with time-varying properties. Such a process is commonly encountered in the process industry, with prevalence in the chemical, food and pharmaceutical manufacturing industries. The controllers are varying in complexity from operator level (rule-based) to expert tuning (computer-aided design) and beyond state of art (generalized fractional-order control). Experimental tests indicate the feasibility of the controllers for variations in time constant with varying operation conditions originating from physical changes in the process. This is rather a common problem in practice and highly relevant for control engineering. Furthermore, an analysis of the system properties reveals the opportunity to operate in closed loop in a self-tuning manner, which avoids the necessity to re-design the controller parameter values.

Cited by
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Journal ArticleDOI

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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