Introducción al control remoto de servomotores industriales

Los sistemas de control de movimiento son parte indispensable de una inmensa cantidad de aplicaciones industriales: sistemas de transporte, sistemas robóticos, sistemas de mecanizado (CNC), sistemas de alimentación de materia prima, sistemas de almacenamiento, etc. Atendiendo a como se consigue controlar el motor que acciona el sistema se pueden distinguir tres grandes alternativas: Variadores de Velocidad o Frecuencia, Motores paso a paso y Servomotores. Desde el punto de vista del control, el más flexible, preciso y completo es el Servomotor por lo que, el desarrollo de la Industria, precisa cada vez más de su utilización. Este proyecto se enfoca en realizar una Introducción completa al control de servomotores industriales desde una exposición teórica hasta un ejemplo de implementación real. Sin perdida de generalidad, todo el documento se desarrolla en el marco de equipos comerciales reales del fabricante Schneider Electric. Sin embargo, como se verá en el último capítulo, todo lo aquí aprendido podrá extrapolarse a los sistemas de control de movimiento propuestos por otros fabricantes (Siemens, ABB, etc). Todo sistema de control de movimiento que cuente con ejes accionados por servomotores cuenta con unos equipos electrónicos denominados servo drives que se encargan del control en posición, velocidad y/o par. En el Capítulo 2 se aglutinan los conceptos teóricos asociados a estos dispositivos (conexionado, modos de funcionamiento, diccionario de parámetros, estructura del regulador, etc.) Un servo accionamiento que se encarga de controlar un eje puede tener que integrarse con otros sistemas/dispositivos que también se dediquen o no al control de movimiento. Para ello, es necesario que exista un controlador de nivel superior (o remoto). En el Capítulo 1 se mencionan distintas alternativas. Todas ellas tienen en común una librería de funciones (Motion Control) que facilitan el manejo y monitorización de los servos. El primer paso para la implantación de estos equipos en cualquier tipo de aplicación será realizar su configuración/parametrización inicial. Por regla general los fabricantes suelen poner a disposición del usuario un software para dicha puesta en marcha. En el Capítulo 1 se explora el ofrecido por Schneider. En numerosas aplicaciones, se precisa que los servomotores sean capaces de trabajar de forma sincronizada entre ellos (o con otro tipo de motores) para realizar tareas como: Alimentar piezas, realizar cortes al vuelo, embotellar líquidos, etc. Por ello, se presenta en el Capítulo 1 una aplicación práctica de sincronización entre dos servomotores utilizando un PLC como controlador remoto. La implementación se describe desde el montaje físico de una maqueta de pruebas hasta la depuración de la aplicación. En el Capítulo 5 se expone, de manera general, como se realiza el control remoto con otra familia de PLCs distinta (M238) a la utilizada en el Capítulo 1 (M340). El objetivo principal es salvar las diferencias entre el software de programación empleado en el M238 (SoMachine) y el utilizado en el M340 (Unity Pro) Por último, en el Capítulo 1 se realizan diferentes propuestas para ampliar o profundizar lo visto en esta Introducción.Motion control systems are crucial for a wide range of industrial applications such as transport systems, robotic systems, machining systems (CNC), raw material feeding systems, storage systems... Depending on how the motor that drives the system is controlled, three main alternatives can be distinguished: Variable Speed or Frequency Drives, Stepper Motors and Servomotors. From the control point of view, the one which provides more flexibility and accuracy is the servomotor. That is why the development of industry increasingly requires them. This project focuses on a complete introduction to the control philosophy of industrial servomotors from the theory to a real implementation. Without loss of generality, the whole document is developed within the framework of real equipment from the manufacturer Schneider Electric. However, as it is stated in the last chapter, everything within this document can be extrapolated to motion control systems made by other manufacturers like Siemens or ABB. Every servomotor has to be connected to an electronic equipment called servo drive which is responsible for its position, speed and torque control. Chapter 2 gathers essential basic theory associated with these devices (connections, operating modes, configurable parameters, controller structure and so on) A servo drive that is in charge of control an axis may need to be integrated with other systems or devices which may or may not also be dedicated to motion control. This requires the existence of a higher-level (or remote) controller. Some commercial alternatives are mentioned in Chapter 3. All of them have in common a function library (Motion Control) that makes easier the handling and monitoring of the servos. The first step for using these devices in any real application consists on carrying out an initial configuration of their parameters. As a rule, manufacturers usually provide their clients with a suitable software for this purpose. Chapter 4 explores the software provided by Schneider that is called SOMove. In many applications, servomotors need to be able to work synchronously with other motors to perform some complex tasks such as feeding parts, flying saw or bottling liquids. For this reason, a practical application of synchronisation between two servomotors using a PLC as a remote controller, can be found on chapter 6. The full implementation is described. From the wiring to the application programming. An HMI has also been developed in order to make several tests. Chapter 5 briefly describes how the remote control is performed with a different PLC family (M238) than the one used in Chapter 6 (M340). One of the main objectives is showing the differences between the programming software used in the M238 (SoMachine) and the one used in the M340 (Unity Pro). Finally, some ideas to keep going into details about servodrives and their applications can be found in Chapter 7.Universidad de Sevilla. Máster en Ingeniería Industria

Dos grupos psicoterapéuticos de pacientes esquizofrénicos: hospitalizados y ambulatorios.

Se describen y comparan distintas características de dos tipos de grupos para pacientes esquizofrénicos: hospitalizados y ambulatorio

Dos grupos psicoterapéuticos de pacientes esquizofrénicos: hospitalizados y ambulatorios.

Se describen y comparan distintas características de dos tipos de grupos para pacientes esquizofrénicos: hospitalizados y ambulatorio

Evaluation of background push content download services to mobile devices over DVB networks

© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper proposes a multicast content download service based on the use of residual network capacity to push multimedia content to available local storage in personal multimedia devices. The service under study is based on the FLUTE protocol. Specifically, FLUTE packets fill the spare capacity in the IP tunnels reserved for the primary streaming service (opportunistic insertion). The paper also evaluates the use of AL-FEC parity to overcome transmission errors,object multiplexing to send the most popular multimedia contents more frequently and cache management policies that consider user preferences in order to keep in storage the most useful items. The service has been evaluated through simulations and measurements performed with an application prototype based on the DVB-H standards. The results show that AL-FEC enables the use of residual capacity for background content download services. In turn, AL-FEC, as well as object multiplexing, improves the relation between the number of content items and the overall access time. Moreover, results show that high percentages of requests can be served from the local cache of the service, provided that it is possible to estimate the popularity of content items and the user preferences.This work was supported by the PAID-05-12 program of the UniversitatPolitecnica de Valencia.Fraile Gil, F.; De Fez Lava, I.; Guerri Cebollada, JC. (2014). Evaluation of background push content download services to mobile devices over DVB networks. IEEE Transactions on Broadcasting. 60(1):1-15. https://doi.org/10.1109/TBC.2013.2289639S11560

Changes in classroom assessment practices during emergency remote teaching due to COVID-19.

This study explores the effects of the shift to emergency remote teaching on assessment practices due to COVID-19 lockdown. A total of 936 Spanish teachers from all educational levels ranging from early childhood to university participated in this nationwide survey. Four aspects were explored: (1) changes in the use of assessment instruments (e.g. exams); (2) changes in assessment criteria, standards and grading; (3) changes in the delivery of feedback and use of rubrics; and (4) changes in students’ involvement in assessment (i.e. self- and peer assessment). In general, results are mixed, with some areas undergoing certain changes with the aim of adapting to the new situation (e.g. primary education teachers lowering their grading standards), whereas many other assessment practices have remained similar, especially among higher education teachers. Unfortunately, some of the assessment practices have worsened, such as students’ involvement in assessment which has decreased.pre-print764 K

A boiler room in a 600-bed hospital complex: study, analysis, and implementation of energy efficiency improvements

Producción CientíficaThe aim of energy efficiency is to use less energy to provide the same service. In hospitals, energy efficiency offers a powerful and cost-effective tool to reduce greenhouse gas emissions, fuel consumption, and also running costs. Over a six-month period, the six gas-fired boilers that provide both a hospital’s heat and hot water were monitored. Analysis of the data obtained led to several actions being implemented in the hospital boiler room control system to improve the efficiency of the heat production system. Comparative studies were conducted, during similar weather periods, of the performance of the hospital’s hot water production system before and after the controls were implemented. Results indicate that the control actions applied proved to be effective. Finally; the paper offers a financial; primary energy saving and CO2 reduction analysis that points to a 3,434.00 €/week savings in natural gas consumption; and a cut in CO2 emissions of 20.3 tons/week; as compared to the reference facility