Robust linearization scheme by structural state feedback for a quadrotor

In this work a feedback linearization technique is proposed, to carry it out to linearize the dynamic model of the quadrotor, a change of variable is introduced that maps the nonlinearities of the system into a nonlinear uncertainty signal contained in the domain of the action of control and is applied to the dynamic model of the quadrotor. To estimate the nonlinear uncertainty signal, the Beard-Jones filter is used, which is based on standard state observers. To verify the effectiveness of the proposed control scheme, experiments are carried out outdoors to follow a circular trajectory in the (x,y) plane. This presented control scheme is suitable for unmanned aerial vehicles where it is important to reject not only non-linearities but also to seek the simplicity and effectiveness of the control scheme for its implementation.

Design, construction and testing of a floating hood biodigester prototype for municipal waste organic waste

This paper documented the design, construction and operation test of a floating hood biodigester prototype, using organic residues (ruminal content, blood, bovine excreta and viscera) from the municipal trail of Ciudad Valles, S.L.P., with the purpose of generating biogas. The components of the biodigester system considered were: loading duct, concrete biodigester tank, biogas pipeline, floating hood, gas reservoir, discharge duct and discharge tank. A biodigester with storage capacity in the 0.178 m3 floating hood was designed for a 30-day trial operation and storage of 0.120 m3 of organic waste mixture in the biodigester tank. As of day 17 of operation the daily average of biogas generated was 0.1801 m3. The composition of the biogas at day 30 of operation, showed a content of 59.4% of CH4. When performing the flame test, an intense blue coloration was obtained, which indicates that the biogas produced has a high calorific value that will allow heating and flammability.

Percepción remota y procesamiento de imágenes para la gestión de cultivos de caña de azúcar

This research work shows that with the use of remote sensing technology it is possible to more effectively fulfill two of the purposes pursued by farmers in the field; manage crops more efficiently and include environmental care in decision-making. Specifically, remote sensing is applied in the context of precision agriculture through geographic information systems (GIS), unmanned aerial vehicles (UAV), multispectral sensors that capture the reflectance of the infrared band of the light spectrum (for interpretation of the biochemical state of the crop), global geopositioning systems (GPS), among others. This study limits the use of this technology to the processing of multispectral images obtained by aerial photogrammetry, and its subsequent treatment for the generation of orthoimages, the calculation of the NDVI vegetation index and the classification of land cover by clustering. Finally, the effect of classification with RGB and multispectral images is analyzed.

Effects of color in humans generated by led lighting systems

This research evaluates the effects of color in humans generated by LED lighting systems. This evaluation allows us to know the different parameters that these systems generate, such as: the temperature and color of light suitable for human vision and thus be able to implement them in LED lighting designs for work areas. Having an adequate lighting system contributes to visual health and safety by avoiding work accidents. Each color has a different percentage of light reflection and in the same way each color affects us optically and psychologically by causing different sensations and perceptions in human beings such as visual fatigue, exhaustion, eye disorders, lacrimation, irritation, stress, migraines and even impaired vision Taking care of visual health is of vital importance. The methodology for evaluating lighting designs will be with NOM-030-ENER-2012. The contribution of this research will be to know the optimal colors and color temperature of light to use in LED lighting systems and to help lighting system designers in the selection of suitable LEDs and area colors that contribute to the visual health of humans

Deshidratación de plátano (Musa paradisiaca) por medio de radiación solar en un secador directo

The objective is to dehydrate banana (Musa paradisiaca) using two direct solar dryers. The purpose of dehydrating the banana, is to give an added value. The fruit is remove the peel, and cut into slices of 1.75 cm radius with a thickness of 0.525 cm. It is placed in two polymer mesh trays with dimensions of 24 cm by 34.2 cm. The initial moisture is determined, and weighed. Later they are introduced to solar dryers. For both dryers the humidity and the temperature of the medium are determined every 15 min, and the color is determined every hour. Finally, the moisture content of the final product is determined. Each test is done in triplicate. The percentage of humidity decreases from 57.23% to 20.87% in natural convection and 20.80% in forced convection. The drying time is 8 hours and the average operating temperature is 38.7 ° C for natural convection and 34.68 ° C for forced convection. In dehydration the percentage of humidity decreases 36.36% on average in the two forms of operation. In forced convection the product darkens less.

Comparaciones ópticas y estructurales de las películas de Óxido de Silicio rico en Silicio (SRO) depositadas por las técnicas LPCVD y HFCVD

In this work, we conducted a comparative study of the optical and structural properties of Silicon Rich Oxide (SRO) films deposited by two chemical vapor deposition techniques: at Low Pressure (LPCVD) and activated by Hot Filament (HFCVD). SRO-LPCVD films were deposited at a silane and nitrous oxide pressures (R_0=P_(N_2 O)/P_(〖SiH〗_4 )) rate of R0=10 y R0=25. SRO-HFCVD films were deposited at a hydrogen pressure of 25 and 100 sccm, at a distance between source and substrate of 8 mm. To improve the optical properties, we have subjected the films obtained by both techniques to thermal treatments at high temperatures. The optical and structural characterizations that we used for comparison of the films were: Null Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR) and Photoluminescence (FL), Scanning Electron Microscopy (SEM) and High-Resolution Transmission Electron Microscopy (HRTEM). The SEM microscopy corroborates the thicknesses of the SRO films obtained by Null Spectroscopy, likewise, the HRTEM microscopy corroborates the diameter size of the silicon nanocrystals (ncs-Si), which also were calculated theoretically with the band gap energy (Eg) obtained in the FL spectra. These characterizations show that either of the two techniques are excellent alternatives for obtaining SRO films with photoluminescent emission, which can be used for photodetector and electroluminescent devices.

Análisis energético de un sistema termoeléctrico para el aprovechamiento del calor residual en un motor Turbofan mediante dinámica de fluidos computacional

This paper shows the energy analysis of a thermoelectric system coupled to a turbofan engine, which is based on the mathematical modeling of the heat transfer of the system during the cogeneration process using fluid dynamics (CFD). The use of waste heat from a turbofan engine would allow us to increase its efficiency which has both economic (due to fuel savings) and environmental (reduction of polluting gases). The proposed section for the installation of the thermoelectric system is the one that covers the turbine and the nozzle section of the turbofan engine, since they are sections in which there are better operating temperatures, in the order of 600 to 200oC. As results of the CFD simulation you get the distribution of temperatures through the thermoelectric and the difference of electrical potential generated. These results determine the overall efficiency of the system and the electrical energy generated by the waste heat. The energy generated by the thermoelectric system can be used in secondary aircraft systems, such as the lighting system, entertainment, etc. The importance of the analysis lies in increasing the overall efficiency of the engine combustion process, to reduce fuel consumption and the costs associated with it.

Control Robusto H∞ en forma Global para Robot Manipulador

In this paper is proposed a solution to the tracking problem with robust H_∞ global control, applied to robot manipulator completely actuated with rotational joint in presence of external disturbances. The Hamilton-Jacobi-Isaacs inequality is verified by a strict function of Lyapunov and enough conditions will be found under which the equilibrium point of the closed-loop system is asymptotically stable globally while the disturbed system has a gain L_2 less than or equal to a predetermined constant. Currently, one of the disadvantages of the H_∞ control, with respect to other control techniques, is the linearization of the system around a point of equilibrium, which converts the Hamilton-Jacobi-Isaacs inequality into algebraic of Riccati equations, which facilitate the solution to the motion control problem H_∞, however, the controller becomes local. Now, through a strict function of Lyapunov it was possible to verify that the Hamilton-Jacobi-Isaacs inequality is satisfied globally. The theory is validated in a robot manipulator with l degree of freedom.

Deshidratador solar híbrido para el secado de plátano

In this work the design of a solar dryer for the dehydration of fruits is presented. Banana is used as raw material for analysis and evaluation purposes. The system is supplied with solar energy in the form of (photovoltaic) PV and (photothermic) PT. The PV part of the dehydrator consists of a solar panel, whose energy supplies electrical resistances to increase the temperature, also feeding a forced air convection system which is carried out with a pair of fans that are at the entrance and exit of the dehydrator, also a control and measurement system. In the other side the PT part consist in a passive storage system of heat direct and indirect catchment of radiation. For the development of the solar dryer it is necessary to take into account certain parameters such as: weather conditions (solar radiation, ambient temperature and wind speed), thermal conductivity, temperature and properties of the components.

Caracterización de un músculo artificial de nylon y su implementación en una articulación de un robot manipulador serial

In this paper we present the study and description of a nylon muscle, to validate its performance and define its properties, applying loads on it and subjecting it to thermal stimuli. The results of the implementation of the nylon muscle are reported in a joint of a rigid mechanism, of a serial manipulator, however, the difficult thermal control that the muscle possesses makes the thermal shock (the ambient temperature and the applied one) wear at a certain point to the muscle, exhausting its properties or a very slow response from it. Testing that the material can only be used in the suspension of the load in the application of rigid systems. It is observed that an important feature of nylon muscles is their incredible capacity to contract loads that are higher than the same weight of the muscle and that by means of a thermal stimulus can be contracted thanks to its anisotropic property, just as the material is extremely attractive for the application of soft robotics and intelligent materials