Showing papers by "Juan I. Yuz published in 2021"
TL;DR: In this paper, a general formulation of 3D compressible fluids based on the port-Hamiltonian framework is presented, both for isentropic and non-isentropical assumptions, describing the energy flux between the mechanical, chemical, and thermal domains, with an explicit characterization of the first and second law of thermodynamics.
Abstract: In this manuscript, a general formulation of 3-dimensional compressible fluids based on the port-Hamiltonian framework is presented, both for isentropic and non-isentropic assumptions, describing the energy flux between the mechanical, chemical, and thermal domains, with an explicit characterization of the first and the second law of thermodynamics. For isentropic fluids, the conversion of kinetic energy into heat by viscous friction is considered as energy dissipation associated with the rotation and compression of the fluid. A dissipative port-Hamiltonian formulation is derived for this class of fluids, including vorticity boundary conditions in the port variables. For non-isentropic fluids, we consider a fluid mixture with multiple chemical reactions. To describe the energy fluxes, we propose a pseudo port-Hamiltonian formulation, which includes the rate of irreversible entropy creation by heat flux, chemical reaction, diffusion of matter, and viscous friction.
4 citations
TL;DR: This paper uses the port-Hamiltonian framework to obtain an energy-based model for the fluid-structure interactions between the vocal folds and the airflow in the glottis, and it is useful to analyze the energy exchange between the airflow and the vocal fold.
Abstract: Lumped elements models of vocal folds are relevant research tools that can enhance the understanding of the pathophysiology of many voice disorders. In this paper, we use the port-Hamiltonian framework to obtain an energy-based model for the fluid-structure interactions between the vocal folds and the airflow in the glottis. The vocal fold behavior is represented by a three-mass model and the airflow is described as a fluid with irrotational flow. The proposed approach allows to go beyond the usual quasi-steady one-dimensional flow assumption in lumped mass models. The simulation results show that the proposed energy-based model successfully reproduces the oscillations of the vocal folds, including the collision phenomena, and it is useful to analyze the energy exchange between the airflow and the vocal folds.
4 citations
TL;DR: In this article, general port-Hamiltonian formulations of multidimensional Maxwell's viscoelastic fluids are considered to describe the energy fluxes in isentropic compressible and incompressible fluids.
2 citations
TL;DR: This study presents the identification, in time and frequency domains, of linear time invariant models of the human subglottal system, for the clinical assessment of vocal function.
1 citations
22 Mar 2021
TL;DR: In this paper, the authors obtained the bondgraph representation of the vocal folds, and then obtained a port-Hamiltonian model based on the mechanical elements that represent the folds in the body cover model (BCM).
Abstract: In this work we obtain the bond-graph representation of the vocal folds, to then obtain a port-Hamiltonian model. This model is based on the mechanical elements that represent the folds in the body cover model (BCM). The obtained port-Hamiltonian system is then discretised using a truncated Taylor series expansion. State and parameter estimation for this discretised model is then performed using an Extended Kalman Filter and Maximum Likelihood, respectively.
22 Mar 2021
TL;DR: In this article, the authors apply Kalman smoothing to estimate the glottal airflow from measurements of an accelerometer placed on the neck skin, and the model used by the smoother is obtained from the frequency response of an impedance-based model and from experimental data obtained in clinical laboratory conditions.
Abstract: The ambulatory monitoring of the vocal folds is a challenging problem that requires accurate modeling of the respiratory system and its interaction with the skin for different patients. Based on these models, filtering or smoothing techniques can be applied in order to estimate the airflow in the glottis and its characteristics from measurements of external ambulatory signals. In this work, we apply Kalman smoothing to estimate the glottal airflow from measurements of an accelerometer placed on the neck skin. In this initial study, the model used by the smoother is obtained from the frequency response of an impedance-based model and from experimental data obtained in clinical laboratory conditions.
01 Aug 2021
TL;DR: In this paper, the authors extended the linear algebra based control design methodology for trajectory control of linear and nonlinear plants, being initially limited to minimum phase plants, to deal with unstable zero dynamics plants.
Abstract: Non-minimum phase plants are always difficult to control. Recently, the so-called Linear Algebra Based Control Design methodology has been used for trajectory control of linear and nonlinear plants, being initially limited to minimum phase plants. In this work, the approach is extended to deal with unstable zero dynamics plants. First, the case of linear plants is analyzed, considering the appearance of a non minimum phase zero. A solution is proposed to deal with the zero in the positive real axis, requiring a reference signal known in advance. Then, the approach is applied to nonlinear plants where the unstable zero dynamics is determined by a single parameter in the plant model. Simulations are included to illustrate the procedure.