Dynamic visual servo control of a 4-axis joint tool to track image trajectories during machining complex shapes

A large part of the new generation of computer numerical control systems has adopted an architecture based on robotic systems. This architecture improves the implementation of many manufacturing processes in terms of flexibility, efficiency, accuracy and velocity. This paper presents a 4-axis robot tool based on a joint structure whose primary use is to perform complex machining shapes in some non-contact processes. A new dynamic visual controller is proposed in order to control the 4-axis joint structure, where image information is used in the control loop to guide the robot tool in the machining task. In addition, this controller eliminates the chaotic joint behavior which appears during tracking of the quasi-repetitive trajectories required in machining processes. Moreover, this robot tool can be coupled to a manipulator robot in order to form a multi-robot platform for complex manufacturing tasks. Therefore, the robot tool could perform a machining task using a piece grasped from the workspace by a manipulator robot. This manipulator robot could be guided by using visual information given by the robot tool, thereby obtaining an intelligent multi-robot platform controlled by only one camera.

Mathematical modelling of the lower urinary tract

The lower urinary tract is one of the most complex biological systems of the human body as it involved hydrodynamic properties of urine and muscle. Moreover, its complexity is increased to be managed by voluntary and involuntary neural systems. In this paper, a mathematical model of the lower urinary tract it is proposed as a preliminary study to better understand its functioning. Furthermore, another goal of that mathematical model proposal is to provide a basis for developing artificial control systems. Lower urinary tract is comprised of two interacting systems: the mechanical system and the neural regulator. The latter has the function of controlling the mechanical system to perform the voiding process. The results of the tests reproduce experimental data with high degree of accuracy. Also, these results indicate that simulations not only with healthy patients but also of patients with dysfunctions with neurological etiology present urodynamic curves very similar to those obtained in clinical studies.

Potential sites for wireless telecommunications facilities

created by the Cape Cod Commission's geographic information systems department.

Projeto de uma antena para controlo wireless de um robot

A comunicação e transmissão de informação sem fios tornou - se uma realidade cada vez mais utilizada pelas sociedades contemporâneas. A nível profissional, as forças armadas de cada país acharam conveniente modernizar os seus meios, por forma a aumentar a eficiência e a segurança em determinadas tarefas. Nesse sentido, o Exército português adquiriu um robot (ROVIM) cuja função é desempenhar ações de reconhecimento e vigilância de modo a obter informações de forma segura. O objetivo desta dissertação é dimensionar e construir uma antena para controlo wireless do robot (ROVIM). As especificações técnicas desta antena requerem dois modos de operação, um com uma largura de feixe larga e outro com uma largura de feixe estreita. Para alcançar esses objetivos dimensionou-se e construiu-se duas antenas. Na dissertação são construídas duas antenas, a primeira é uma antena Yagi – Uda convencional e a segunda é uma antena com uma estrutura nova que permite a regulação do ganho e da largura de feixe a -3 dB. A primeira antena será o modelo base da segunda antena, que apresenta a inovação do controlo das caraterísticas de radiação. Esse controlo é possível através da introdução de díodos e do respetivo circuito de polarização na estrutura da antena. Inicialmente, as antenas foram dimensionadas e simuladas recorrendo ao programa de simulação CST MWS, de modo a operarem na banda dos 2,4 GHz. Após a construção das antenas, as caraterísticas de radiação foram medidas recorrendo à câmara anecoica e ao network analyzer, permitindo assim a comparação dos resultados medidos com os simulados.

Allegations of improper lobbying by Department of Defense personnel of the C-5B and B-1B aircraft and sale to Saudi Arabia of the airborne warning and control system : report together with separate views of the Investigations Subcommittee of the Committee on Armed Services, House of Representatives, Ninety-seventh Congress, second session, December 30, 1982.

Mode of access: Internet.

Fabrication, installation, test and evaluation of motorcycle controls and displays; gear position, indicator, non-linear throttle, tactile indicator of neutral position. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

An initial assessment of the literature on the measurement, control, transport, transformation and health effects of unregulated diesel engine emissions. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Survey of driver aid devices for improved fuel economy. Interim report.

Transportation Systems Center, Cambridge, Mass.

Damage to vehicle safety and engine exhaust emissions systems in collision. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Model framework for management control over automated information system /

Mode of access: Internet.

Assessment of the capacity of the automated radar terminal systems (ARTS IIIA) for the years 1980-1990 /

Mode of access: Internet.

Peace by committee : command and control issues in multinational peace enforcement operations /

Originally presented as thesis at School of Advanced Airpower Studies, Air University, 1993-94.

SSB(N) quiet steering system study (Phase I).

Mode of access: Internet.

A comparative evaluation of alternative systems for the provision of effective access to periodical literature : a report to the National Commission on Libraries and Information Science /

Mode of access: Internet.

Strategic command, control, and communications : alternative approaches for modernization /

Item 1005-C