DISEÑO Y ANÁLISIS CINEMÁTICO DE UN ROBOT PARALELO PARA REHABILITACIÓN DE CADERA

ResumenEn la vida cotidiana se presentan problemas que debilitan los músculos debido a situaciones como: una edad avanzada, accidentes o enfermedades. Esta debilidad o pérdida de movilidad, ocasiona rigidez en las articulaciones lo que ocasiona pérdida en el rango de movimiento.Para recuperar la capacidad de movimiento, los músculos débiles podrían fortalecerse utilizando dispositivos de rehabilitación o tratamiento ortopédico. La creciente necesidad actual de aplicación de terapias de rehabilitación y la falta de clínicas y personal especializado aumenta la necesidad de implementar robots que realicen estas tareas que resultan repetitivas y cansadas para el fisioterapista.En este artículo se presenta el diseño y análisis cinemático de un robot paralelo para rehabilitación de la cadera de tres grados de libertad que proporciona los seis movimientos que se requieren: flexión-extensión, abducción-aducción, y rotación interna-externa.El robot paralelo propuesto consta de tres actuadores conformados de un motor de CD acoplado a una corredera lineal accionada por un tornillo sinfín, cada actuador está colocado en cada uno de los tres ejes cartesianos X, Y y Z. Se presentan resultados de simulación del análisis cinemático utilizando programas especializados.Palabra(s) Clave: Robot paralelo, rehabilitador de cadera, análisis cinemático. DESIGN AND KINEMATIC ANALYSIS OF A PARALLEL ROBOT FOR HIP REHABILITATIONAbstractIn activities of daily living problems are presented that weaken muscles due to situations such as: an advanced age, accidents or illness. This weakness or loss of mobility causes stiffness in the joints resulting in loss of range of motion.To regain movement capacity, weak muscles could be strengthened using rehabilitation or orthopedic devices. The growing need for rehabilitation therapies and the lack of clinics and specialized personnel increases the need to implement robots that perform these tasks that are repetitive and tire for the physiotherapist.This paper presents the kinematic design and analysis of a parallel robot for hip rehabilitation of three degrees of freedom that provides the six movements that are required: flexion-extension, abduction-adduction, and internal-external rotation.The proposed parallel robot consists of three actuators consist of a CD motor coupled to a linear guide system; each actuator is placed in each of the three Cartesian axes X, Y and Z. Some simulation results of analysis using specialized software are presented.Keywords: Parallel robot, hip rehabilitation, kinematics analysis

DISEÑO DE SISTEMAS MECATRÓNICOS: PROTOTIPOS VIRTUALES (DESIGN OF MECHATRONIC SYSTEMS: VIRTUAL PROTOTYPES)

En la actualidad existe una vasta cantidad de productos mecatrónicos en todos los sectores productivos: máquinas herramientas y robots en las industrias, máquinas de envasado y embalado, automóviles y aeronaves para servicio a la sociedad, entre otros. La Ingeniería Mecatrónica es una sinergia de varias disciplinas de ingeniería como la mecánica, electrónica, control y sistemas informáticos para el diseño y fabricación de productos electromecánicos inteligentes. En el diseño de productos mecatrónicos se debe de lograr la sinergia en el sistema mecánico y sistema de control, para obtener productos eficientes, que cumplan con la función para el que fue diseñado. Para lograr esto, el proceso de diseño se basa principalmente en el uso de software de diseño y análisis utilizando prototipos virtuales. En este artículo se muestran las ventajas del uso de software en el proceso de diseño de productos mecatrónicos.Palabra(s) Clave: Diseño mecatrónico, prototipos virtuales, Software MSC ADAMS, modelo de simulación digital. AbstractCurrently there is a vast number of mechatronic products in all productive sectors. Machine tools and robots in industries, bottle soda filling and packaging machines, automobiles and aircraft for service to society, among others. Mechatronics is a synergy of several engineering disciplines such as mechanics, electronics, control and computer systems for the design and manufacture of intelligent electromechanical products. In the design of mechatronic products, synergy should be achieved between the mechanical and control system, to obtain efficient products that fulfill the function for which it was designed. To achieve this, the design process is mainly based on the use of design and analysis software, using virtual prototypes. This paper presents the advantages of using software in the process of designing mechatronic products.Keywords: Mechatronic design, virtual prototype, MSC Adams software, digital simulation model

Design of a new cutting tool for drill bits

Traditional manufacturing techniques applied in the Mexican Mining Industry require a high number of experimental tests, long periods of machining time used, and high economic costs are generated. To solve this problem, it is proposed to use the computational simulation technique, which turns out to be a faster, low-cost, highly accurate, simple, and reliable technique to evaluate the performance of a cutting tool. In addition, with this technique, it is possible to simulate different geometries during the machining process, without generating economic losses and increasing the test accuracy. For this reason, the objective of this work was to design and validate a new cutting tool for the internal string of drill bits used in mining. The methodology used was through the implementation of the computational simulation technique and later the manufacture of the new tool. Which was mounted on a computerized numerical control lathe, and it was simultaneously introduced into the drill bit to perform the machining of the internal chord. To find the optimal geometry of such a tool, the finite element and design of experiment methods are used. Among the main results of this work is to identify the model that showed the best maximum effort performance, and that allows us to have a high safety factor. The deformation shown by the new cutting tool allows the manufactured parts to have adequate dimensional tolerances for their fit in the drill bit. The validation of the cutting tool design was carried out considering the cutting force that is generated in the machining process.Las técnicas tradicionales de manufactura en la Industria Minera Mexicana, requieren de un alto número de pruebas experimentales, utilizan largos periodos de tiempo de maquinado y generan altos costos económicos. Para resolver tal problemática, se propone utilizar la técnica de simulación computacional, la cual resulta ser una técnica más rápida, de bajo costo, de gran exactitud, sencilla y confiable para evaluar el desempeño de una herramienta de corte. Además, con esta técnica es posible simular diferentes geometrías durante el proceso de maquinado. Es por ello, que el objetivo del presente trabajo fue diseñar y validar una nueva herramienta de corte para la cuerda interna de brocas de perforación utilizadas en la minería. La metodología utilizada fue mediante la implementación de la técnica de simulación computacional y posteriormente la manufactura de la nueva herramienta. Posteriormente, fue necesario montar tal herramienta en un torno de control numérico computarizado, y simultáneamente introducirla al interior de la broca de perforación para realizar el maquinado de la cuerda interna. Para encontrar la geometría óptima de la herramienta se utilizan los métodos del elemento finito y de diseño de experimentos. Entre los principales resultados de este trabajo se encontró el determinar la geometría de la herramienta de corte que mostró el mejor desempeño de esfuerzo máximo, y que permite tener un factor de seguridad alto.La deformación que mostró la nueva herramienta de corte, permite que las piezas fabricadas tengan tolerancias dimensionales adecuadas para su ajuste en la broca de perforación. La validación del diseño de la herramienta de corte se realizó considerando la fuerza de corte que se genera en el proceso de maquinado

Incorporating Breast Asymmetry Studies into CADx Systems

Breast cancer is one of the global leading causes of death among women, and an early detection is of uttermost importance to reduce mortality rates. Screening mammograms, in which radiologists rely only on their eyesight, are one of the most used early detection methods. However, characteristics, such as the asymmetry between breasts, a feature that could be very difficult to visually quantize, is key to breast cancer detection. Due to the highly heterogeneous and deformable structure of the breast itself, incorporating asymmetry measurements into an automated detection system is still a challenge. In this study, we proposed the use of a bilateral registration algorithm as an effective way to automatically measure mirror asymmetry. Furthermore, this information was fed to a machine learning algorithm to improve the accuracy of the model. In this study, 449 subjects (197 with calcifications, 207 with masses, and 45 healthy subjects) from a public database were used to train and evaluate the proposed methodology. Using this procedure, we were able to independently identify subjects with calcifications (accuracy = 0.825, AUC = 0.882) and masses (accuracy = 0.698, AUC = 0.807) from healthy subjects

Synthesis of ZnO:Li films using an Arduino-based Hydrothermal reactor: An application to solar cells

Solar energy becomes more important in society, due to the low level of pollution it produces compared to fossil fuels. One way to take advantage of solar energy is using solar cells, which are made with zinc oxide films. To have its synthesis it is necessary to use a hydrothermal reactor,which has become increasingly expensive. Making it unavailable to most educational institutionsand the private sector. To solve the problem of its high cost, the aim of this work was tomanufacture a hydrothermal reactor based on Arduino, with an automation system with agitation,temperature-pressure control and low cost. This through a simple and practical methodology, which is focuses on users without deep knowledge in electronics and programming. SolidWorks®software was used for physical design and stress validation in the hydrothermal reactor. The cost of the reactor proposed in this work is 6 times lower than the cost of a commercial reactor. To validate the reliability of the reactor, three lithium-doped zinc oxide films with different molarities were synthesized. These films presented a transmittance response equivalent to that reported in theliterature. Finally, it is intended that the relevance of this work is to encourage users, through the proposed methodology, to manufacture not only a hydrothermal reactor, but also to manufacturecomplex laboratory equipment.La energía solar cobra mayor importancia en la sociedad, debido al bajo nivel de contaminación que produce en comparación con los combustibles fósiles. Una forma de aprovechar la energía solar es mediante el uso de celdas solares, que se fabrican con películas de óxido de zinc. Para su síntesis, es necesario utilizar un reactor hidrotermal, que se ha vuelto cada vez más costoso.Haciéndolo inaccesible para la mayoría de las instituciones educativas y el sector privado. Para solucionar el problema de su alto costo, el objetivo de este trabajo fue fabricar un reactor hidrotermal basado en Arduino, con un sistema de automatización con agitación, control de temperatura-presión y de bajo costo. Esto a través de una metodología sencilla y práctica, que está enfocada a usuarios sin conocimientos profundos en electrónica y programación. Se utilizó el software SolidWorks® para el diseño físico y la validación de esfuerzos en el reactor hidrotermal.El costo del reactor propuesto en este trabajo es 6 veces menor que el costo de un reactor comercial.Para validar la confiabilidad del reactor, se sintetizaron tres películas de óxido de zinc dopadas con litio con diferentes molaridades. Estas películas presentaron una respuesta de transmitancia equivalente a la reportada en la literatura. Finalmente, se pretende que la relevancia de este trabajo sea incentivar a usuarios, a través de la metodología propuesta, a fabricar no solo un reactor hidrotermal, sino también en fabricar complejos equipos de laboratorio

Turbulent Kinetic Energy Distribution of Nutrient Solution Flow in NFT Hydroponic Systems Using Computational Fluid Dynamics

Hydroponics is crucial for providing feasible and economical alternatives when soils are not available for conventional farming. Scholars have raised questions regarding the ideal nutrient solution flow rate to increase the weight and height of hydroponic crops. This paper presents the turbulent kinetic energy distribution of the nutrient solution flow in a nutrient film technique (NFT) hydroponic system using the computational fluid dynamics (CFD) method. Its main objective is to determine the dynamics of nutrient solution flow. To conduct this study, a virtual NFT hydroponic system was modeled. To determine the turbulent kinetic energy distribution in the virtual NFT hydroponic system, we conducted a CFD analysis with different pipe diameters (3.5, 9.5, and 15.5 mm) and flow rates (0.75, 1.5, 3, and 6 L min−1). The simulation results indicate that different pipe diameters and flow rates in NFT hydroponic systems vary the turbulent kinetic energy distribution of nutrient solution flow around plastic mesh pots

On the State-Feedback Controller Design for Polynomial Linear Parameter-Varying Systems with Pole Placement within Linear Matrix Inequality Regions

The present paper addresses linear parameter-varying systems with high-order time-varying parameter dependency known as polynomial LPV systems and their controller design. Throughout this work, a procedure ensuring a state-feedback controller from a parameterized linear matrix inequality (PLMI) solution is presented. As the main contribution of this paper, the controller is designed by considering the time-varying parameter rate as a tuning parameter with a continuous control gain in such a way that the closed-loop eigenvalues lie in a complex plane subset, with high-order time-varying parameters defining the system dynamics. Simulation results are presented, aiming to show the effectiveness of the proposed controller design