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A multidimensional scaling classification of robotic sensors
Lima, Miguel; Machado, J. A. TenreiroThis chapter analyzes the signals captured during impacts and vibrations of a mechanical manipulator. Eighteen signals are captured and several metrics are calculated between them, such as the correlation, the mutual information and the entropy. A sensor classification scheme based on the multidimensional scaling technique is presented.
A multidimensional scaling analysis of musical sounds based on pseudo phase plane
Lima, Miguel; Costa, António Cardoso; Machado, J. A. TenreiroThis paper studies musical opus from the point of view of three mathematical tools: entropy, pseudo phase plane (PPP), and multidimensional scaling (MDS). The experiments analyze ten sets of different musical styles. First, for each musical composition, the PPP is produced using the time series lags captured by the average mutual information. Second, to unravel hidden relationships between the musical styles th...
Adaptação da interface de webmail às actividades de cada utilizador
Lima, Miguel Ângelo OliveiraEstágio realizado na Portugalmail e orientado pelo Eng.º Nuno Lopes ; Tese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 2009
Experimental backlash study in mechanical manipulators
Lima, Miguel; Machado, J. A. Tenreiro; Crisóstomo, ManuelThe behavior of mechanical manipulators with backlash is analyzed. In order to acquire and study the signals an experimental setup is implemented. The signal processing capabilities of the wavelets are used for de-noising the experimental signals and the energy of the obtained components is analyzed. To evaluate the backlash effect upon the robotic system, it is proposed an index based on the pseudo phase plane...
A sensor classification strategy for robotic manipulators using multidimensiona...
Lima, Miguel; Machado, J. A. TenreiroThis paper analyzes the signals captured during impacts and vibrations of a mechanical manipulator. To test the impacts, a flexible beam is clamped to the end-effector of a manipulator that is programmed in a way such that the rod moves against a rigid surface. Eighteen signals are captured and theirs correlation are calculated. A sensor classification scheme based on the multidimensional scaling technique is p...
Fractional dynamics in liquid manipulation
Lima, Miguel; Machado, J. A. TenreiroThis paper presents a fractional calculus perspective in the study of signals captured during the movement of a mechanical manipulator carrying a liquid container. In order to study the signals an experimental setup is implemented. The system acquires data from the sensors, in real time, and, in a second phase, processes them through an analysis package. The analysis package runs off-line and handles the record...
A sensor classification strategy for robotic manipulators
Lima, Miguel; Machado, J. A. Tenreiro; Ferrolho, AntónioIn practice the robotic manipulators present some degree of unwanted vibrations. The advent of lightweight arm manipulators, mainly in the aerospace industry, where weight is an important issue, leads to the problem of intense vibrations. On the other hand, robots interacting with the environment often generate impacts that propagate through the mechanical structure and produce also vibrations. In order to anal...
Análise dinâmica de vibrações em manipuladores robóticos
Lima, Miguel Francisco Martins deOs manipuladores robóticos apresentam vibrações indesejadas durante o seu funcionamento. Por um lado, estas vibrações resultam de numerosos factores, tais como, folgas, flexibilidades, atritos, não-linearidades e outras causas. Por outro lado, os robôs, ao interagirem com o meio ambiente, geram frequentemente impactos que produzem vibrações que se propagam através de toda a estrutura mecânica. Neste contexto, d...
Robotic manipulators with vibrations: short time fourier transform of fractiona...
Lima, Miguel; Machado, J. A. Tenreiro; Crisóstomo, ManuelThis paper analyzes the signals captured during impacts and vibrations of a mechanical manipulator. In order to acquire and study the signals an experimental setup is implemented. The signals are treated through signal processing tools such as the fast Fourier transform and the short time Fourier transform. The results show that the Fourier spectrum of several signals presents a non integer behavior. The experi...
Avaliação de metodos de contribuição de grupos para uso em calculos de equilibr...
Claudio de Lima Miguel MartinezA methodology for predicting vapour-liquid equilibrium curves using group contribution methods is proposed. From the molecular structure of the compound, values of normal boiling temperature, critical properties, acentric factor, second virial coefficients, vapor pressure, activity coefficients and molar liquid volume are required since they are necessary in isothermic and isobaric bubble- and dew- points calcu...
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