Modelling, simulation, and calibration of twin rotor mimo system

Helicopter is an aircraft that plays important role in transporting products, people…in society nowadays. It is complex mechanical equipment that corresponds many fields such as fluid mechanics, mechanics, control…Design it probably easy but fabrication and control it are not simple problem. The aim of research is to obtain a simulation and control model for the setup that has the principle of function like a real helicopter in laboratory in Automatic Control Department in Technical University Catalonia – Barcelona. This setup names Twin Rotor Multi Inputs - Multi Outputs System (TRMS) is manufactured by the Feedback Instruments Limited Company. It serves as a guide for the control tasks and provides useful information about the physical behavior of the system. It is also useful setup for study and practice of students to have a clearer look. On the main originalities of the present master thesis is the use on a control oriented model based on the use of a model that has linear structure but parameters varying with the operating point. This type of model is known as Linear Parameter Varying model (shortly, LPV model). Two procedures to obtain such a model are proposed. One based of rearranging the non-linear equations in such a way that the LPV parameters appear linearly. The second is based on linearizing the non-linear model around different operating points and the interpolation the parameters between them. Finally, the LPV model for the TRMS system obtained using either of the procedures described above can be calibrated using standard parameter estimation algorithms available in the Identification Toolbox in MATLAB

Modelling, simulation, and calibration of twin rotor mimo system

Helicopter is an aircraft that plays important role in transporting products, people…in society nowadays. It is complex mechanical equipment that corresponds many fields such as fluid mechanics, mechanics, control…Design it probably easy but fabrication and control it are not simple problem. The aim of research is to obtain a simulation and control model for the setup that has the principle of function like a real helicopter in laboratory in Automatic Control Department in Technical University Catalonia – Barcelona. This setup names Twin Rotor Multi Inputs - Multi Outputs System (TRMS) is manufactured by the Feedback Instruments Limited Company. It serves as a guide for the control tasks and provides useful information about the physical behavior of the system. It is also useful setup for study and practice of students to have a clearer look. On the main originalities of the present master thesis is the use on a control oriented model based on the use of a model that has linear structure but parameters varying with the operating point. This type of model is known as Linear Parameter Varying model (shortly, LPV model). Two procedures to obtain such a model are proposed. One based of rearranging the non-linear equations in such a way that the LPV parameters appear linearly. The second is based on linearizing the non-linear model around different operating points and the interpolation the parameters between them. Finally, the LPV model for the TRMS system obtained using either of the procedures described above can be calibrated using standard parameter estimation algorithms available in the Identification Toolbox in MATLAB

Towards a Robust WiFi-based Fall Detection with Adversarial Data Augmentation

Recent WiFi-based fall detection systems have drawn much attention due to their advantages over other sensory systems. Various implementations have achieved impressive progress in performance, thanks to machine learning and deep learning techniques. However, many of such high accuracy systems have low reliability as they fail to achieve robustness in unseen environments. To address that, this paper investigates a method of generalization through adversarial data augmentation. Our results show a slight improvement in deep learning-systems in unseen domains, though the performance is not significant.Comment: Will appear in Proceedings of the 54th Annual Conference on Information Sciences and Systems (CISS2020

Investigation of optical absorptance of onedimensionally periodic silicon gratings as solar absorbers for solar cells

A rigorous design using periodic silicon (Si) gratings as absorbers for solar cells in visible and near-infrared regions is numerically presented. The structure consists of a subwavelength Si grating layer on top of an Si substrate. Ranges of grating dimensions are preliminary considered satisfying simple and feasible fabrication techniques with an aspect ratio defined as the ratio of the grating thickness (d) and the grating lamella width (w), with 0 < d/w < 1.0. The subwavelength grating structure (SGS) is assumed to comprise different lamella widths and slits within each period in order to finely tune the grating profile such that the absorptance is significantly enhanced in the whole wavelength region. The results showed that the compound SGS yields an average absorptance of 0.92 which is 1.5 larger than that of the Si plain and conventional grating structures. It is shown that the absorptance spectrum of the proposed SGS is insensitive to the angle of incidence of the incoming light. The absorptance enhancement is also investigated by computing magnetic field, energy density, and Poynting vector distributions. The results presented in this study show that the proposed method based on nanofabrication techniques provides a simple and promising solution to design solar energy absorbers or other energy harvesting devices.Web of Science22S1A79A6

Imperfectly geometric shapes of nanograting structures as solar absorbers with superior performance for solar cells

The expectation of perfectly geometric shapes of subwavelength grating (SWG) structures such as smoothness of sidewalls and sharp corners and nonexistence of grating defects is not realistic due to micro/nanofabrication processes. This work numerically investigates optical properties of an optimal solar absorber comprising a single-layered silicon (Si) SWG deposited on a finite Si substrate, with a careful consideration given to effects of various types of its imperfect geometry. The absorptance spectra of the solar absorber with different geometric shapes, namely, the grating with attached nanometer-sized features at the top and bottom of sidewalls and periodic defects within four and ten grating periods are investigated comprehensively. It is found that the grating with attached features at the bottom absorbs more energy than both the one at the top and the perfect grating. In addition, it is shown that the grating with defects in each fourth period exhibits the highest average absorptance (91%) compared with that of the grating having defects in each tenth period (89%), the grating with attached features (89%), and the perfect one (86%). Moreover, the results indicate that the absorptance spectrum of the imperfect structures is insensitive to angles of incidence. Furthermore, the absorptance enhancement is clearly demonstrated by computing magnetic field, energy density, and Poynting vector distributions. The results presented in this study prove that imperfect geometries of the nanograting structure display a higher absorptance than the perfect one, and provide such a practical guideline for nanofabrication capabilities necessary to be considered by structure designers.Web of Science22S2A294A28

Dual broadband infrared absorptance enhanced by magnetic polaritons using graphene-covered compound metal gratings

A dual broadband perfect absorber based on a graphene-covered compound silver (Ag) grating structure working in the infrared (0.8-2.1 mu m) regime is proposed and investigated numerically. Two distinct absorption peaks approximately 1.0 are achieved by the excitation of magnetic polaritons over a large range of incident angles from 0 to 70 degrees. The physics underlying the structure is also explained by computing interactions of electromagnetic fields with the graphene and the Ag grating. In addition, it has shown that the absorption peaks can be tuned by changing geometric parameters of the structure; however, their spectral shape and absorption remain unchanged. Furthermore, the proposed compound grating with a graphene overlay provides potential applications for infrared absorbing devices.Web of Science2721301903018

Wavelength-selective emitters with pyramid nanogratings enhanced by multiple resonance modes

Binary gratings with high or low metal filling ratios in a grating region have been demonstrated as successful candidates in enhancing the emittance of emitters for thermophotovoltaics since they could support surface plasmons (SPs), the Rayleigh–Wood anomaly (RWA), or cavity resonance (CR) within their geometries. This work shows that combining a tungsten binary grating with a low and high filling ratio to form a pyramid grating can significantly increase the emittance, which is nearly perfect in the wavelength region from 0.6 to 1.72 μm, while being 0.1 at wavelengths longer than 2.5 μm. Moreover, the emittance spectrum of the hybrid tungsten grating is insensitive to the angle of incidence. The enhancement demonstrated by magnetic field and Poynting vector patterns is due to the interplay between SPs and RWA modes at short wavelengths, and CR at long wavelengths. Furthermore, a combined grating made of nickel is also proposed providing enhanced emittance in a wide angle of incidence.Web of Science2715art. no. 15540

A tool for checking CSP||B specifications

International audienceThis paper reports about our experience with building a simple tool to assist us in the verification of CSP||B specifications. We present the Control Loop Invariant technique to check the consistency of a CSP||B specification. From this, we deduce the requirements of an assistant tool. The tool was developed in Ocaml. We discuss several issues observed during the development

Effects of dietary tryptophan on cannibalism, survival and growth of Wallago attu (Bloch & Schneider, 1801) juveniles

This study aims to evaluate the effects of supplemented commercial diets with tryptophan (TRP) on plasma serotonin, cannibalism, survival rate, and growth of Wallago attu (helicopter catfish). After one week of acclimation, 3,200 juveniles of helicopter catfish (BW = 2.5 ± 0.27 g, total length = 5.6 ± 0.43 cm) were randomly assigned for the experiment in fifteen plastic tanks (200 L). The experiment was conducted with five treatments (CT – 0 g TRP/kg – control group, T1 – 5 g TRP/kg, T2 – 10 g TRP/kg, T3 – 20 g TRP/kg, and T4 – 40 g TRP/kg) in a completely randomized design with three replications for four weeks. The results from the enzyme-linked immunosorbent assay reveal that TRP-supplemented diets effectively increased the serotonin level (5-HT) in the plasma of the catfish. The serotonin level increased with the dose of TRP added to the feed. Furthermore, a higher TRP level significantly decreased cannibalism and improved the final survival of the fish. However, the fish’s growth rate among treatments T1, T2, T3, and T4 was not significantly different, but there was a statistical difference between the experimental treatments and the CT treatment. The findings of this study suggest that TRP could be supplemented at a dose of 20 g·kg–1 to the feed to reduce cannibalism and improve the final survival of helicopter catfish