An effective strategy of real-time vision-based control for a Stewart platform

© 2018 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 worksA Stewart platform is a kind of parallel robot which can be used for a wide variety of technological and industrial applications. In this paper, a Stewart platform designed and assembled at the Universitat Polit`ecnica de Catalunya (UPC) by our research group is presented. The main objective is to overcome the enormous difficulties that arise when a real-time vision-based control of a fast moving object placed on these mechanisms is required. In addition, a description of its geometric characteristics, the calibration process, together with an illustrative experiment to demonstrate the good behavior of the platform is given.Postprint (author's final draft

An Active helideck testbed for floating structures based on a Stewart-Gough platform

A parallel robot testbed based on Stewart-Gough platform called Active-helideck is designed, developed and tested as a helicopter floating helideck. The objective of this testbed is to show the advantages of helicopters that use an active helideck upon landing on and taking off from ships or from offshore structures. Active-helideck compensates simulated movements of a ship at sea. The main goal of this study is to maintain the robot’s end effector (helideck) in a quasi-static position in accordance to an absolute inertial frame. Compensation is carried out through the coordinate action of its six prismatic actuators in function of an inertial measurement unit. Moreover, the simulation of the sea movement is done by a parallel robot called ship platform with three degrees of freedom. The ship platform is built with a vertical oscillation along the z axis, i.e. heave, and rotates on remaining axes, i.e. roll and pitch. Active helideck is able to compensate simulated movements by considering the ship as an inertial frame as observed in the experiment

Intelligent Products: Shifting the Production Control Logic in Construction (With Lean and BIM)

Production management and control in construction has not been addressed/updated ever since the introduction of Critical Path Method and the Last Planner® system. The predominant outside-in control logic and a fragmented and deep supply chain in construction significantly affect the efficiency over a lifecycle. In a construction project, a large number of organisations interact with the product throughout the process, requiring a significant amount of information handling and synchronisation between these organisations. However, due to the deep supply chains and problems with lack of information integration, the information flow down across the lifecycle poses a significant challenge. This research proposes a product centric system, where the control logic of the production process is embedded within the individual components from the design phase. The solution is enabled by a number of technologies and tools such as Building Information Modelling, Internet of Things, Messaging Systems and within the conceptual process framework of Lean Construction. The vision encompasses the lifecycle of projects from design to construction and maintenance, where the products can interact with the environment and its actors through various stages supporting a variety of actions. The vision and the tools and technologies required to support it are described in this pape

Equal Voice for America's Families

Outlines September 2010 discussions, including the need for refined strategies to advance the low-income working families' movement for community change, collaboration, innovation, accountability, and capacity building. Assesses progress by issue area

Planning and implementation of effective collaboration in construction projects

The 21st century is now seen as the time for the construction industry to embrace new ways of working if it is to continue to be competitive and meet the needs of its ever demanding clients. Collaborative working is considered by many to be essential if design and construction teams are to consider the whole lifecycle of the construction product. Much of the recent work on collaborative working has focused on the delivery of technological solutions with a focus on web (extranets), CAD (visualisation), and knowledge management technologies. However, it is now recognised that good collaboration does not result from the implementation of information technology solutions alone. The organisational and people issues, which are not readily solved by pure technical systems, need to be resolved. However, approaches that exclusively focus on organisational and people issues will not reap the benefits derived from the use of technology, especially in the context of distributed teams which are the norm in construction. Work currently being undertaken at Loughborough University aims to bring together the benefits enabled by the technology, with the organisational, and its people issues to provide a framework enabling high level strategic decisions to be made to implement effective collaboration. This paper reports on the initial stages of the project: the background to the project, the methodology used, and findings from the literature survey and the requirements capture survey conducted as part of the project

Development of kinematic equations and determination of workspace of a 6 DOF end-effector with closed-kinematic chain mechanism

This report presents results from the research grant entitled Active Control of Robot Manipulators, funded by the Goddard Space Flight Center, under Grant NAG5-780, for the period July 1, 1988 to January 1, 1989. An analysis is presented of a 6 degree-of-freedom robot end-effector built to study telerobotic assembly of NASA hardware in space. Since the end-effector is required to perform high precision motion in a limited workspace, closed-kinematic mechanisms are chosen for its design. A closed-form solution is obtained for the inverse kinematic problem and an iterative procedure employing Newton-Raphson method is proposed to solve the forward kinematic problem. A study of the end-effector workspace results in a general procedure for the workspace determination based on link constraints. Computer simulation results are presented

Business Strategies for Transitions towards Sustainable Systems

This paper develops a strategic perspective for business to address persistent sustainability issues by contributing to the innovation of societal systems. Sustainability issues at the level of societal sectors or domains cannot be addressed by single organizations but require co-evolutionary changes in technology, economy, culture and organizational forms. We present the case of transition management in the Netherlands – an approach combining systems analysis with new modes of governance to influence the direction and speed of structural changes towards sustainability – and the activities of two firms working in this new context. From the two specific cases we conceptualize business strategies at different levels to advance sustainable development.transition management;sustainability;business development;systems

Educational change and ICT: an exploration of priorities 2 and 3 of the DfES e-strategy in schools and colleges: the current landscape and implementation issues

Landscape review of integrated online support for learners and collaborative approaches to personalised learning activities