Author
Isabela Roxana Birs
Other affiliations: Control Group, Ghent University
Bio: Isabela Roxana Birs 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 9, co-authored 51 publications receiving 288 citations. Previous affiliations of Isabela Roxana Birs include Control Group & Ghent University.
Papers
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19 May 2016TL;DR: In this paper, a novel tuning procedure is proposed based on solving a set of nonlinear complex equations that directly aim at reducing the resonant peak, making sure that the best ones are chosen.
Abstract: Cantilever beams have an important role in day to day life in bridges, towers, buildings and aircraft wings, making active vibration suppression a highly researched field. The purpose of this paper is to detail the design of fractional order PID controllers for smart beams. A novel tuning procedure is proposed based on solving a set of nonlinear complex equations that directly aim at reducing the resonant peak. The control parameters are computed through optimization techniques, making sure that the best ones are chosen. The practical stand was realized using magnet-coil approach and not piezoelectric actuators. The experimentally obtained vibration results prove that fractional order PID controllers can be used in practice to significantly reduce the amplitude and settling time of the vibrating system.
11 citations
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01 Dec 2017TL;DR: An experimental platform that simulates the circulatory system: the passing of blood from arteries to smaller blood vessels, while also capturing the non-Newtonian characteristic of the blood.
Abstract: Targeted drug delivery is a focus point in recent advances in the nanomedical field due to its many advantages such as decreased side effects, faster action and better drug absorption with less substance used. The paper presents an experimental platform that simulates the circulatory system: the passing of blood from arteries to smaller blood vessels, while also capturing the non-Newtonian characteristic of the blood. The targeted drug delivery is ensured by a scalable submersible equipped with various sensors and actuators such that the real-time position of the submersible can be determined and controlled in the circulatory system. The purpose of the presented work is to provide a solid foundation for experimental modeling of the interaction between the submersible and non-Newtonian fluids and for validating different control strategies suitable for velocity control. The experimental setup takes into account the real life difficulties of targeted drug delivery.
11 citations
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01 Jan 2017TL;DR: In this article, the authors presented the tuning of two controllers: Linear Quadratic Regulator and Fractional Order Proportional Derivative controller, which were tested on a smart beam, vibrations being mitigated through piezoelectric patches.
Abstract: The smart beam is widely used as a means of studying the dynamics and active vibration suppression possibilities in aircraft wings. The advantages obtained through this approach are numerous, among them being aircraft stability and manoeuvrability, turbulence immunity, passenger safety and reduced fatigue damage. The paper presents the tuning of two controllers: Linear Quadratic Regulator and Fractional Order Proportional Derivative controller. The active vibration control methods were tested on a smart beam, vibrations being mitigated through piezoelectric patches. The obtained experimental results are compared in terms of settling time and control effort, experimentally proving that both types of controllers can be successfully used to reduce oscillations. The analysis in this paper provides for a necessary premise regarding the tuning of a fractional order enhanced Linear Quadratic Regulator, by combining the advantages of both control strategies.
8 citations
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01 Mar 2018
TL;DR: In this paper, a first order transfer function with time delay is developed to make the connection between the voltage applied to the motor actuating the propeller and the velocity of the submersible.
Abstract: This paper presents the modeling and control of a small scale submersible equipped with one propeller. The modeling process takes into consideration physical elements such as fluid statics, viscous damping and propulsive thrust. A first order transfer function with time delay is developed to make the connection between the voltage applied to the motor actuating the propeller and the velocity of the submersible. The velocity control is realized with a Fractional Order Proportional Integral (FOPI) controller that ensures zero steady state error. The controller is designed based on frequency domain specifications such as gain crossover frequency, phase margin and robustness to gain variations. The obtained fractional controller is validated through simulation in terms of steady state error and disturbance rejection performance.
8 citations
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01 Nov 2016TL;DR: A fractional order Proportional Derivative controller, designed using frequency domain specifications, is proposed and experimental results show that the proposed method leads to significant improvement of the closed loop behavior.
Abstract: Vibration occurs in numerous important domains, such as the aerospace industry, and has negative effects since it can limit the life span of the devices, cause malfunctioning or even system instability. The necessity of research on vibration suppression in aeroplane wings is important from a scientific and technologic point of view: to provide better, more efficient, robust, cheaper solutions to eliminate vibrations effects, which triggers the socioeconomic aspect regarding the increase of flight safety and passenger comfort. Vibration suppression can be achieved using passive techniques, but they come along with certain disadvantages related to efficiency/costs. An alternative solution is to use active control. Several active control strategies have been proposed so far, with aeroplane wings/helicopter blades simulated as smart cantilever beams. The present paper proposes a fractional order Proportional Derivative controller, designed using frequency domain specifications. The case study consists in a smart beam equipped with dedicated sensors and actuators. The experimental results, considering both passive and active control responses of the smart beam, show that the proposed method leads to significant improvement of the closed loop behavior.
7 citations
Cited by
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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
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
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TL;DR: The Viscosity can be imagined as the force that should be applied to a layer of fluid belonging to the plane fixed to the velocity of the layer placed at a fixed distance.
Abstract: The Viscosity can be imagined as the force that should be applied to a layer of fluid belonging to the plane fixed to the velocity of the layer placed at a fixed distance. For example a fluid flowing in a tube at different speeds: the minimum speed is in the edge of the section (due to friction) and the maximum speed is at the center. The viscosity in this example is that pressure which is exerted on the wall allows a constant speed on the whole section.
157 citations
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TL;DR: Explicit formulas and graphs of few special functions are derived in this article on the basis of various definitions of various fractional derivatives and their applications are also reviewed in the paper, where the authors also review their applications.
Abstract: Explicit formula and graphs of few special functions are derived in the paper on the basis of various definitions of various fractional derivatives and various fractional integrals. Their applications are also reviewed in the paper.
140 citations
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TL;DR: This paper helps beginners to get started rapidly and learn how to select, tune, approximate, discretize, and implement FO-controllers in the frequency domain.
110 citations