Ionut Muntean

A Theoretical Study on Modeling the Respiratory Tract With Ladder Networks by Means of Intrinsic Fractal Geometry

Fractional order modeling of biological systems has received significant interest in the research community. Since the fractal geometry is characterized by a recurrent structure, the self-similar branching arrangement of the airways makes the respiratory system an ideal candidate for the application of fractional calculus theory. To demonstrate the link between the recurrence of the respiratory tree and the appearance of a fractional-order model, we develop an anatomically consistent representation of the respiratory system. This model is capable of simulating the mechanical properties of the lungs and we compare the model output with in vivo measurements of the respiratory input impedance collected in 20 healthy subjects. This paper provides further proof of the underlying fractal geometry of the human lungs, and the consequent appearance of constant-phase behavior in the total respiratory impedance.

Cloud E-learning for Mechatronics

This paper describes results of the CLEM project, Cloud E-learning for Mechatronics. CLEM is an example of a domain-specific cloud that is especially tuned to the needs of VET (Vocational, Education and Training) teachers. An interesting development has been the creation of remote laboratories in the cloud. Learners can access such laboratories to support their practical learning of mechatronics without the need to set up laboratories at their own institutions. The cloud infrastructure enables multiple laboratories to come together virtually to create an ecosystem for educators and learners. From such a system, educators can pick and mix materials to create suitable courses for their students and the learners can experience different types of devices and laboratories through the cloud. The paper provides an overview of this new cloud-based e-learning approach and presents the results. The paper explains how the use of cloud computing has enabled the development of a new method, showing how a holistic e-learning experience can be obtained through use of static, dynamic and interactive material together with facilities for collaboration and innovation. We have designed and developed a new customized cloud platform for e-learning.We have designed and developed a new cloud framework to model mechatronic devices.We have evaluated the system with users and teachers in the field.The proposed system is the first cloud based e-learning system for mechatronics.

RGA analysis and decentralized control for a wastewater treatment plant

A vital process in wastewater treatment is the biological treatment with activated sludge. In Romania, there are still plenty of cases where the biological treatment stage is operated manually, leading to inefficient operation and implicitly to higher operational costs, increased difficulty in maintaining the quality of the effluent and less disturbance rejection capabilities. In our paper, we show that using a medium-fidelity first principle model and by carrying out an RGA analysis, a decentralized control strategy using PI controllers can be easily developed and tested before implementation, the control strategy giving good results in disturbance rejection and trajectory tracking.

A Simulator for the Respiratory Tree in Healthy Subjects Derived from Continued Fractions Expansions

Taking into account the self‐similar recurrent geometrical structure of the human respiratory tree, the total respiratory impedance can be represented using an electrical equivalent of a ladder network model. In this paper, the parameters of the respiratory tree are employed in simulation, based on clinical insight and morphology. Once the transfer function of the total input impedance model is calculated, it is further interpreted in its continued fraction expansion form. The purpose is to compare the ladder network structure with the continuous fraction expansion form of the impedance. The results are supporting the theory of fractional‐order impedance appearance (also known as constant‐phase behaviour) and help understanding the mathematical and morphological basis for constructing a physiology‐based simulator of the human lungs.

Internal model control for a hydraulically driven robotic arm

The robotic arm presented in this paper is part of an unloading machine used in the process of hot rolling to extract the heated billets from inside the rotary hearth furnace. The robotic arm positioning is hydraulically driven due to higher speed response. For the horizontal positioning of the arm a control structure is needed since the displacement of a billet is constantly changing. It is intended by means of this paper to obtain a control structure using the internal model control method that improves the performances of the current control systems that are mostly tuned based on rich experience. The results assessment is done by means of simulation and the obtained controllers are compared on the basis of overall performances.

Modeling and composition estimation of an isotopic distillation column

In order to effectively implement model-based control algorithms in distillation processes, when no composition measurements are available, a state estimator is compulsory. A full-order nonlinear observer used as composition estimator is presented and implemented on an isotopic cryogenic distillation process used for the enrichment of 13C from carbon monoxide. The observer was developed by extending the modeling equations of the process, therefore, the implementation is very easy to be carried out, when in possession of a first principle model of the process in study.

Remote Management: An Architecture for Mechatronic Systems

Cloud computing has proved to bring many advantages to its users from industry where it has been applied for data analysis, operator training or for the delivery of infrastructure or applications on demand. While some of these applications are still under development, the benefits that cloud computing offers, such as low cost, flexibility and speed of adding additional infrastructure will push forward its implementation on more processes. In this paper we will present an architecture for the remote management of mechatronic systems that will allow users to take advantage of the potential of cloud computing. The paper also contains a review of Software as a Service solutions available on the market, solutions that can be integrated in the remote management. Even though the paper focuses on mechatronic systems, the same architecture can be used on other applications.

A general distillation modeling framework applied to an isotopic distillation column

Being one of the most approached subjects in the field of chemical engineering, a lot of numerical modeling methods for the distillation columns were presented in scientific papers. This means that in order to find a model that would suit a specific process requires a considerable amount of time. This paper will present a general first principle model that aims at providing users with a framework that can be easily adapted for any type of distillation process. In order to prove these assumptions an isotopic distillation process for the enrichment of 13C has been selected.

Economic optimization of a thermal cracker via model predictive control technology

An ethylene plant is one of the largest chemical plants and ethylene is industrially obtained through thermal cracking of hydrocarbons. The cracking furnace is the heart of such an installation and the frequent changes in feed mix, quality and prices; and the demand for its olefin products are influencing directly the production efficiency. Each reactant in the feed produces a certain distribution of products and in order to satisfy the demand constraints at the lowest cost; one needs to optimize the amounts of each reactant.

Digitization of continuous interval transfer functions: A revisited method and its application on a case study

A method that uses the Boxer-Thaler integrator to obtain an approximate discrete-time transfer function for uncertain continuous systems with interval uncertainties is revisited. The advantage of the approach lies in the fact that the interval structure of the continuous system is preserved in the resulting discrete model. This allows the application of existing robust results to the discretized system and minimize the search space in the uncertainty region. The method is also applied to a control loop from a multi-sidestream distillation column.