25,375 research outputs found
The uses and abuses of personal UAS
No full textNano UAVs promise much in terms of enhanced personal reconn aissance capabilities. But according to Dr Stephen Prior, there are a number of drawbacks to small multi-rotor aircraft, and the cost of procuring them is still relatively high. Does growing civilian use of these systems hold the key
Revisiting revisitation in computer interaction: organic bookmark management
No full textAccording to Milic-Frayling et al. (2004), there are two general ways of user browsing i.e. search (finding a website where the user has never visited before) and revisitation (returning to a website where the user has visited in the past). The issue of search is relevant to search engine technology, whilst revisitation concerns web usage and browser history mechanisms. The support for revisitation is normally through a set of functional built-in icons e.g. History, Back, Forward and Bookmarks. Nevertheless, for returning web users, they normally find it is easier and faster to re-launch an online search again, rather than spending time to find a particular web site from their personal bookmark and history records. Tauscher and Greenberg (1997) showed that revisiting web pages forms up to 58% of the recurrence rate of web browsing. Cockburn and McKenzie (2001) also stated that 81% of web pages have been previously visited by the user. According to Obendorf et al. (2007), revisitation can be divided into four classifications based on time: short-term (72.6% revisits within an hour), medium-term (12% revisits within a day and 7.8% revisits within a week), and long-term (7.6% revisits longer than a week
The rise of the Micro Air Vehicle
No full textInterview between Jon Excell (Editor) and Stephen Prior.UAVs (Unmanned air vehicles) are now a regular feature of modern warfare. Widely used for reconnaissance, and increasingly deployed in an offensive capacity, the technology is developing fast — with engineers adding ever-increasing levels of autonomy and performance improvements that could soon put UAVs on a par with manned aircraft
An electric wheelchair mounted robotic arm - a survey of potential users
No full textThis paper describes the results of a survey which investigated and evaluated the needs and abilities of electric wheelchair users. The results of this survey will be used to develop a low-cost electric wheelchair-mounted robotic arm for use by physically disabled people to facilitate rehabilitation. The survey was undertaken by the author together with staff and students from occupational therapist training colleges, using a four-page questionnaire containing over 110 questions. The questionnaire was developed by the author together with Dr Robin Platts (Director of Orthotics), Mr Ian Bayley (Director of the London Spinal Unit) and senior occupational therapists at the Royal National Orthopaedic Hospital, Stanmore, Middlesex. After a successful trial the questionnaire was used with 50 severely disabled people from various backgrounds and social circumstances. The results of this survey show that the average electric wheelchair user is 40 years old, single (68%), living at home (58%) with family support (69%) and without any paid employment (79%). The most prevalent disability is spinal cord injury (24%) followed by multiple sclerosis (16%). The survey has identified several tasks which electric wheelchair users find impossible to do, and some of these will form part of the design specification. Finally 84% of the survey subjects would consider buying such a robotic ai
Service-oriented models for audiovisual content storage
No full textWhat are the important topics to understand if involved with storage services to hold digital audiovisual content? This report takes a look at how content is created and moves into and out of storage; the storage service value networks and architectures found now and expected in the future; what sort of data transfer is expected to and from an audiovisual archive; what transfer protocols to use; and a summary of security and interface issues
Optimizing small multi-rotor unmanned aircraft: a practical design guide
No full textThis design guide was written to capture the author’s practical experience of designing, building and testing multi-rotor drone systems over the past decade. The lack of one single source of useful information meant that the past 10 years has been a steep learning curve, a lot of self-tuition and many trial and error tests. Lessons learnt the hard way are not always the best way to learn. This book will be useful for the amateur drone pilot who wants to build their own system from first principles, as well as the academic researcher investigating novel design concepts and future drone applications
Including design in e-manufacturing
No full textThis paper reviews major issues in the implementation of e-manufacturing, particularly the design aspects. It will examine recent progress, drawing out particular issues that are being addressed. Use will be made of the work by the author and colleagues to devise rule-based design and Internet-based control of machines to illustrate how these developments affect the integrated e-manufacturing environment. A dynamic Simulink model of the way e-manufacture is affected by overall design delays is used to evaluate general solutions for partial and complete e-based companies. These models show how changing to improved designs reduces WI
A novel method of sensing and classifying terrain for autonomous unmanned ground vehicles
No full textUnmanned Ground Vehicles (UGVs) play a vital role in preserving human life during hostile military operations and extend our reach by exploring extraterrestrial worlds during space missions. These systems generally have to operate in unstructured environments which contain dynamic variables and unpredictable obstacles, making the seemingly simple task of traversing from A-B extremely difficult. Terrain is one of the biggest obstacles within these environments as it could potentially cause a vehicle to become stuck and render it useless, therefore autonomous systems must possess the ability to directly sense terrain conditions. Current autonomous vehicles use look-ahead vision systems and passive laser scanners to navigate a safe path around obstacles; however these methods lack detail when considering terrain as they make predictions using estimations of the terrain’s appearance alone. This study establishes a more accurate method of measuring, classifying and monitoring terrain in real-time. A novel instrument for measuring direct terrain features at the wheel-terrain contact interface is presented in the form of the Force Sensing Wheel (FSW). Additionally a classification method using unique parameters of the wheel-terrain interaction is used to identify and monitor terrain conditions in real-time. The combination of both the FSW and real-time classification method facilitates better traversal decisions, creating a more Terrain Capable system
Energy conservation techniques: increasing the endurance of small UAVs
No full textAll small Unmanned Aircraft (UA) have severe limitations from a lack of endurance capability. This is a direct result of using battery technologies which are limited in their capacity, current capability, mass and energy density. The most widely used chemistry in small battery powered UAVs is Li-Po with its peak energy density of about 200 Wh/kg. Much research has been directed at finding alternative power sources, from Solar, Hydrogen Fuel Cells to Nuclear batteries. The latest contender is Li-S chemistries which appear to offer energy densities of up to 400 Wh/kg within the next 2 years. Li-S batteries claim to be safer in terms of damage tolerance and the lack of thermal runaway, which can be an issue with the current generation Li-Po batteries. This presentation will outline the alternatives and point towards the likely future direction of this technology. The author will also present other design strategies and design tools which help to promote the efficient use of power within these types of Unmanned Aircraft
Development of a reconfigurable protective system for multi-rotor UAS
No full textThe purpose of this study is to illustrate how the design and deployment of a minimal protective system for multi-rotorcraft can cater for changes in legislation and provide for greater use both in and outdoors. A methodology is presented to evaluate the design and development of a system which protects both single axial and co-axial rotorcraft. The key emphasis of the development presented is the scenario in which the multi-rotorcraft can fly with increased speed including the capability of flying through windows and doors without the fear of system failure due to rotor disruption. Discussed as well is the degree of autonomy the reconfigurable system should feature as well as the effects of drag and added component mass to the performance of the system
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