Escuela Superior de Enseñanzas Técnicas

Purpose: The purpose of this paper is to present the development and validation of a methodology which allows modeling and solving the inverse and direct dynamic problem in real time in robot manipulators. Design/methodology/approach: The robot dynamic equation is based on the Gibbs‐Appell equation of motion, yielding a well‐structured set of equations that can be computed in real time. This paper deals with the implementation and calculation of the inverse and direct dynamic problem in robots, with an application to the real‐time control of a PUMA 560 industrial robot provided with an open control architecture based on an industrial personal computer. Findings: The experimental results show the validity of the dynamic model and that the proposed resolution method for the dynamic problem in real time is suitable for control purposes. Research limitations/implications: The accuracy of the applied friction model determines the accuracy of the identified overall model and consequently of the control. This is especially obvious in the case of the PUMA 560 robot, in which the presence of friction is remarkable in some of their joints. Hence, future work should focus on identifying a more precise friction model. The robot model could also be extended by incorporating rotor dynamics and could be applied for different robot configurations as parallel robots. Originality/value: Gibbs‐Appell equations are used in order to develop the robotic manipulator dynamic model, instead of more usual dynamics formulations, due to several advantages that these exhibit. The obtained non‐physical identified parameters are adapted in order to enable their use in a control algorithm.

In 1984, German furniture-maker Axel Bruchhäuser reached out to architectural duo Alison (1928–93) and Peter Smithson (1923–2003) with a playful letter ostensibly written by his cat and addressed to theirs. The letter between cats inquired about commissioning the Smithsons to build several lookouts on Bruchhäuser’s home, known locally as the “Hexenhaus” (the “Witches’ House”—a common name in the area where the Brothers Grimm wrote their fairy tales). Started in 1986 and completed in 2001, and located in a dense forest in Hessen, the renovation that the Smithsons undertook constituted an example of what they called “law of the conglomerate.” Step by step, the house was expanded and opened to admit the light as well the trees, which became part of the interior. The house’s primary materials are wood and glass, providing a poetic example of latticework and a stunning use of natural light.

A series of four Christmas-themed exhibitions spanning 1976–81 formed cumulative parts of a single project and offered the Smithsons an opportunity to explore a renewed ‘art of inhabitation’.

The aim of this study was to investigate, using three-dimensional finite element analysis [3D-FEA], the stress and/or strain distribution of five different resin composites used in combination with carbon fibre posts. FEA models of five different light-cured composites were employed. The stress distribution of composite in combination with carbon fibre post was analysed under two different loading conditions: (i) polymerization shrinkage and (ii) load of 150 N with a 35° tilt to the long axis of the tooth. The Material Fatigue Rate [MFR%] of composite materials, dentin and fibre post was calculated. The highest stress values were recorded for Heliomolar and Clearfil-Photo P. The lowest stresses and MFR% values were attained when using Diamond Crown. High MFR% value [>45%] for carbon posts were found in all the tested cases under load. Composite materials with a Young’s modulus similar to that of dentin should be selected for the restoration of endodontically-treated teeth when using carbon fibre posts. The peak of the polymerization stress of the composite core is localized at the ferrule level. This might induce an open margin with higher risk of coronal leakage.

This work summarizes several years of measurements of the main noise sources present in large populations, specially the noise produced by the traffic in the city of Valencia. The study includes one-week monitoring in the period between the years 2012 and 2014 in three different types of scenarios (heavy, medium and low traffic). The aim of this work is firstly to determine the most representative measurement day under several approaches related to the type of day (working day, non-working day or full week), and to the different periods throughout the day (night, day and evening). This permits to reach conclusions about the optimization of measurement techniques of the overall urban traffic noise, and will facilitate the measurement tasks in specific locations of the city of Valencia, characterized by specific traffic conditions.