Positioning Control System for a Large Range 2D Platform with Submicrometre Accuracy for Metrological and Manufacturing Applications

The importance of nanotechnology in the world of Science and Technology has rapidly increased over recent decades, demanding positioning systems capable of providing accurate positioning in large working ranges. In this line of research, a nanopositioning platform, the NanoPla, has been developed at the University of Zaragoza. The NanoPla has a large working range of 50 mm × 50 mm and submicrometre accuracy. The NanoPla actuators are four Halbach linear motors and it implements planar motion. In addition, a 2D plane mirror laser interferometer system works as positioning sensor. One of the targets of the NanoPla is to implement commercial devices when possible. Therefore, a commercial control hardware designed for generic three phase motors has been selected to control and drive the Halbach linear motors.This thesis develops 2D positioning control strategy for large range accurate positioning systems and implements it in the NanoPla. The developed control system coordinates the performance of the four Halbach linear motors and integrates the 2D laser system positioning feedback. In order to improve the positioning accuracy, a self calibration procedure for the characterisation of the geometrical errors of the 2D laser system is proposed. The contributors to the final NanoPla positioning errors are analysed and the final positioning uncertainty (k=2) of the 2D control system is calculated to be ±0.5 µm. The resultant uncertainty is much lower than the NanoPla required positioning accuracy, broadening its applicability scope.<br /

Positioning uncertainty of the control system for the planar motion of a nanopositioning platform

The novel nanopositioning platform (NanoPla) that is in development at the University of Zaragoza has been designed to achieve nanometre resolution in a large working range of 50 mm × 50 mm. The 2D movement is performed by four custom-made Halbach linear motors and a 2D laser system provides positioning feedback, while the moving part of the platform is levitating and unguided. As control hardware, this work proposes the use of a commercial solution, in contrast to other systems, where the control hardware and software were specifically designed for the purpose. In a previous work of this research, the control system of one linear motor implemented in the selected commercial hardware was presented. In this study, the developed control system is extended to the four motors of the nanopositioning platform to generate a 2D planar movement in the whole working range of the nanopositioning platform. In addition, the positioning uncertainty of the control system is assessed. The obtained results satisfy the working requirements of the NanoPla, achieving a positioning uncertainty of ±0.5 µm along the whole working range

Desarrollo de un sistema flexible de micro-posicionado 2D

El proyecto consiste en el diseño, cálculo, simulación por elementos finitos, fabricación y prueba de un primer prototipo de sistema flexible de micro-posicionado 2D. El diseño se basa en un modelo previamente concebido en la UNCC (Universitý of North Carolina at Charlotte). El proyecto tiene como objetivos: 1. Validación o modificación, según el caso, de diferentes aspectos del diseño adoptado a partir de los resultados obtenidos en las diferentes fases (cálculo, simulación y prueba, además de otros experimentos que puedan tener lugar) 2. Convenientemente discutidos y contrastados los resultados obtenidos en las diferentes fases del proyecto, se propondrán las líneas futuras de trabajo a seguir en las fases posteriores del desarrollo de la plataforma

Revisión, auditoría y actualización a nuevas directrices del sistema de Garantía Interna de la Calidad de la Escuela de Ingeniería y Arquitectura

El Sistema de Garantía Interna de Calidad (SGIC) implantado en la Escuela de Ingeniería y Arquitectura (EINA) de Zaragoza cuenta con el certificado de calidad otorgado por la Agencia Nacional de Evaluación de la Calidad y Acreditación (ANECA), desde Noviembre de 2013. Para mantener esta certificación y que continúe siendo un Sistema fiable y evolutivo es necesario realizar una actualización y revisión constante del mismo, con el fin de reflejar la realidad de la institución y la actividad que se desarrolla en el centro. De esta manera, se logrará renovar la acreditación del Sistema, prevista para este año 2017. Es esta necesidad de mejora continua y de renovación de la acreditación el motivo de creación de este Trabajo de Fin de Grado, cuyo objetivo principal es la revisión del SGIC del centro y actualización y/o adaptación de los principales documentos que lo describen, prestando especial énfasis en los procedimientos. El método seguido para lograr esta revisión se ha centrado principalmente en la realización de una auditoría interna inicial, con objeto de conocer los puntos débiles y trabajar más profundamente en ellos, y en la actualización individual de los procedimientos, con la consiguiente adaptación de sus Anexos, del Mapa de Procesos del Sistema, e incluso del Manual de Calidad del centro. Además, se realiza una auditoría final con el fin de comprobar las mejoras implantadas y se plantea una propuesta de modificación de la sección de Garantía de la Calidad de la Página Web de la EINA

Study of Augmented Reality based manufacturing for further integration of quality control 4.0: a systematic literature review

Augmented Reality (AR) has gradually become a mainstream technology enabling Industry 4.0 and its maturity has also grown over time. AR has been applied to support different processes on the shop-floor level, such as assembly, maintenance, etc. As various processes in manufacturing require high quality and near-zero error rates to ensure the demands and safety of end-users, AR can also equip operators with immersive interfaces to enhance productivity, accuracy and autonomy in the quality sector. However, there is currently no systematic review paper about AR technology enhancing the quality sector. The purpose of this paper is to conduct a systematic literature review (SLR) to conclude about the emerging interest in using AR as an assisting technology for the quality sector in an industry 4.0 context. Five research questions (RQs), with a set of selection criteria, are predefined to support the objectives of this SLR. In addition, different research databases are used for the paper identification phase following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) methodology to find the answers for the predefined RQs. It is found that, in spite of staying behind the assembly and maintenance sector in terms of AR-based solutions, there is a tendency towards interest in developing and implementing AR-assisted quality applications. There are three main categories of current AR-based solutions for quality sector, which are AR-based apps as a virtual Lean tool, AR-assisted metrology and AR-based solutions for in-line quality control. In this SLR, an AR architecture layer framework has been improved to classify articles into different layers which are finally integrated into a systematic design and development methodology for the development of long-term AR-based solutions for the quality sector in the future

Preliminary Modelling and Implementation of the 2D-control for a Nanopositioning Long Range Stage

Different systems are recently developed to obtain effective positioning at nanometer scale with increased working ranges. For this purpose, a two-dimensional nanopositioning platform (NanoPla) has been design and manufactured. To assure the demanding metrological performance the drive and control system is being defined and validated. Based on four home-made linear motors as actuators, this work is focused on the study of the control-loop for 1D- and 2D-cases with the aim of the preliminary modelling and posterior implementation. The different required blocks are presented and an initial controller solution is proposed to achieve the established positioning requests

Design optimization for the measurement accuracy improvement of a large range nanopositioning stage

Both an accurate machine design and an adequate metrology loop definition are critical factors when precision positioning represents a key issue for the final system performance. This article discusses the error budget methodology as an advantageous technique to improve the measurement accuracy of a 2D-long range stage during its design phase. The nanopositioning platform NanoPla is here presented. Its specifications, e.g., XY-travel range of 50 mm ˆ 50 mm and sub-micrometric accuracy; and some novel designed solutions, e.g., a three-layer and two-stage architecture are described. Once defined the prototype, an error analysis is performed to propose improvement design features. Then, the metrology loop of the system is mathematically modelled to define the propagation of the different sources. Several simplifications and design hypothesis are justified and validated, including the assumption of rigid body behavior, which is demonstrated after a finite element analysis verification. The different error sources and their estimated contributions are enumerated in order to conclude with the final error values obtained from the error budget. The measurement deviations obtained demonstrate the important influence of the working environmental conditions, the flatness error of the plane mirror reflectors and the accurate manufacture and assembly of the components forming the metrological loop. Thus, a temperature control of ¿0.1 ¿C results in an acceptable maximum positioning error for the developed NanoPla stage, i.e., 41 nm, 36 nm and 48 nm in X-, Y- and Z-axis, respectively

Traceable onboard metrology for machine tools and large-scale systems

Esta tesis doctoral persigue la mejora de las funcionalidades de las máquinas herramienta para la fabricación de componentes de alto valor añadido. En concreto, la tesis se centra en mejorar la precisión de las máquinas herramienta en todo su volumen de trabajo y en desarrollar el conocimiento para realizar la medición por coordenadas trazable con este medio productivo. En realidad, la tecnología para realizar mediciones en máquina herramienta ya está disponible, como son los palpadores de contacto y los softwares de medición, sin embargo, hay varios factores que limitan la trazabilidad de la medición realizada en condiciones de taller, que no permiten emplear estas medidas para controlar el proceso de fabricación o validar la pieza en la propia máquina-herramienta, asegurando un proceso de fabricación de cero-defectos. Aquí, se propone el empleo del documento técnico ISO 15530-3 para piezas de tamaño medio. Para las piezas de gran tamaño se presenta una nueva metodología basada en la guía VDI 2617-11, que no está limitada por el empleo de una pieza patrón para caracterizar el error sistemático de la medición por coordenadas en la máquina-herramienta. De esta forma, se propone una calibración previa de la máquina-herramienta mediante una solución de multilateración integrada en máquina, que se traduce en la automatización del proceso de verificación y permite reducir el tiempo y la incertidumbre de medida. En paralelo, con el conocimiento generado en la integración de esta solución en la máquina-herramienta, se propone un nuevo procedimiento para la caracterización de la precisión de apunte del telescopio LSST en todo su rango de trabajo. Este nuevo procedimiento presenta una solución automática e integrada con tecnología láser tracker para aplicaciones de gran tamaño donde la precisión del sistema es un requerimiento clave para su buen funcionamiento.<br /

In-process portable photogrammetry using optical targets for large scale industrial metrology

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