721 research outputs found

    Empirical measurements of small unmanned aerial vehicle co-axial rotor systems

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    Small unmanned aerial vehicles (SUAV) are beginning to dominate the area of intelligence, surveillance, target acquisition and reconnaissance (ISTAR) in forward operating battlefield scenarios. Of particular interest are vertical take-off and landing (VTOL) variants. Within this category co-axial rotor designs have been adopted due to their inherent advantages of size and power to weight ratio. The inter-rotor spacing attribute of a co-axial rotor system appears to offer insight into the optimum design characteristic. The H/D ratio has been cited as a significant factor in many research papers, but to date has lacked an empirical value or an optimal dimensionless condition. In this paper the H/D ratio of a SUAV has been explored thoroughly, reviewing the performance of these systems at incremental stages, the findings from this study have shown that a range of H/D ratios in the region of (0.41-0.65) is advantageous in the performance of SUAV systems. This finding lends itself to the theory of inter-rotor spacing as a non-dimensionally similar figure, which cannot be applied across a spectrum of systems; this could be attributed to the viscous losses of flight at low Reynolds Numbers (< 50,000

    Design and development of a pole climbing surveillance robot

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    The cost of installing, monitoring and servicing a fixed camera system can be high and not all areas are in need of constant surveying. The increase in crime in urban areas emphasizes the need for a more effective and efficient surveillance system, as a result could lead to fewer crimes. A temporary surveillance unit which is able to climb to gain an elevated view has great potential for both military and civilian application. This paper highlights how the patent pending climbing robotic system (PC-101) was developed to be used by London’s Metropolitan Police Forensic Department for analysing outdoor crime scenes especially that related to car accidents. When cars are involved in accidents in the Metropolitan area, depending on the scale of the incident, the road generally has to be shut off to traffic if there are serious casualties. Elevated images are required for cases which may be taken to court, which then the images are then used as evidence, therefore regulations on the quality and perspectives of the image have to be met. By climbing a range of existing street furniture such as street lamp post, a temporary platform eliminates the use of larger special vehicle which struggles to get to the crime scene as well as cuts down the duration of the road closure. 98% of London street lamps in the Metropolitan area are constructed out of steel structures which make the use of magnetic wheels for locomotion an ideal solution to the climbing problem. Once remote controlled to the top of the lamp post, the PC-101 makes use of its actuated camera arm/gimbal to take the required shot, which can be seen on the ground control unit. A surveillance tool of this sort can be used for many applications which include crowd/riot control, crime scene investigations, monitoring hostile environments and even the monitoring of nature within urban environment

    Developing a low-cost beer dispensing robotic system for the service industry

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    As the prices of commercially available electronic and mechanical components decrease, manufacturers such as Devantech and Revolution Education have made encoded motor controller systems and microcontrollers very accessible to engineers and designers. This has made it possible to design sophisticated robotic and mechatronic systems very rapidly and at relatively low cost. A recent project in the Autonomous Systems Lab at Middlesex University, UK was to design and build a small, automated, robotic bartender based around the 5 litre Heineken 'Draughtkeg' system, which is capable of patrolling a bar and dispensing beer when signalled to by a customer. Because the system was designed as a commercial product, design constraints focused on keeping the build cost down, and so electronic components were sourced from outside companies and interfaced with a bespoke chassis and custom mechanical parts designed and manufactured on site at the University. All the programming was conducted using the proprietary BASIC language, which is freely available from the PicAXE supplier at no cost. This paper will discuss the restrictions involved in building a robot chassis around 'off-theshelf' components, and the issues arising from making the human-machine interaction intuitive whilst only using low-cost ultrasonic sensors. Programming issues will also be discussed, such as the control of accuracy when interfacing a PicAXE microcontroller with a Devantech MD25 Motor Controller board. Public live testing of the system was conducted at the Kinetica Art Fair 2010 event in London and has since been picked up by websites such as Engadget.com and many others. Feedback on the system will be described, as well as the refinements made as a result of these test

    Investigating the use of unmanned plant machinery on construction sites

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    The UK Construction Sector has been estimated to contribute 8% of the UK’s GDP [1]. The worldwide recession has forced construction companies to introduce and adopt cost saving measures to increase productivity. Several robotic building systems are in development for the Construction Sector such as the PERI’s Automatic Climbing System [2] and Brokk’s remote-controlled demolition machines [3], but there has been little implementation on live sites. Construction sites by their very nature are dynamically changing environments, so if human input was removed entirely, a robot would need a high level of awareness of the current state of the building project in order to navigate and carry out its task

    Hybrid Planning: Task-Space Control and Sampling-Based Planning

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    Haschke R. Hybrid Planning: Task-Space Control and Sampling-Based Planning. In: Workshop on Robot Motion Planning: Online, Reactive, and in Real-time. 2012.We propose a hybrid approach to motion planning for redundant robots, which combines a powerful control framework with a sampling-based planner. We argue that a suitably chosen task controller already manages a huge amount of trajectory planning work. However, due to its local approach to obstacle avoidance, it may get stuck in local minima. Therefore we augment it with a globally acting planner, which operates in a lower-dimensional search space, thus circumventing the curse of dimensionality afflicting modern, many-DoF robots

    The Warnie volcanic province : Jurassic intraplate volcanism in Central Australia

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    We wish to thank Santos Ltd. for providing us with the Snowball 3D seismic survey. In particular we wish to thank Jenni Clifford and Lance Holmes who provided helpful feedback and 2D seismic lines covering the Lambda 1, Orientos 2 and Warnie East 1 wells. We also wish to thank Beach Energy, in particular Rob Menpes, for the helpful discussions and feedback on the manuscript in addition to helping us with the analysis of the magnetic data. The work contained in this paper contains work conducted during a PhD study undertaken as part of the Natural Environment Research Council (NERC) Centre for Doctoral Training (CDT) in Oil & Gas [grant number NEM00578X/1] and is fully funded by NERC whose support is gratefully acknowledged. Lastly, the two anonymous reviews of the manuscript are thanked for their insightful and constructive comments that significantly improved the work presented.Peer reviewedPostprin

    Investigation of rheumatoid arthritis susceptibility loci in juvenile idiopathic arthritis confirms high degree of overlap

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    <p>Objectives: Rheumatoid arthritis (RA) shares some similar clinical and pathological features with juvenile idiopathic arthritis (JIA); indeed, the strategy of investigating whether RA susceptibility loci also confer susceptibility to JIA has already proved highly successful in identifying novel JIA loci. A plethora of newly validated RA loci has been reported in the past year. Therefore, the aim of this study was to investigate these single nucleotide polymorphisms (SNP) to determine if they were also associated with JIA.</p> <p>Methods: Thirty-four SNP that showed validated association with RA and had not been investigated previously in the UK JIA cohort were genotyped in JIA cases (n=1242), healthy controls (n=4281), and data were extracted for approximately 5380 UK Caucasian controls from the Wellcome Trust Case–Control Consortium 2. Genotype and allele frequencies were compared between cases with JIA and controls using PLINK. A replication cohort of 813 JIA cases and 3058 controls from the USA was available for validation of any significant findings.</p> <p>Results: Thirteen SNP showed significant association (p<0.05) with JIA and for all but one the direction of association was the same as in RA. Of the eight loci that were tested, three showed significant association in the US cohort.</p> <p>Conclusions: A novel JIA susceptibility locus was identified, CD247, which represents another JIA susceptibility gene whose protein product is important in T-cell activation and signalling. The authors have also confirmed association of the PTPN2 and IL2RA genes with JIA, both reaching genome-wide significance in the combined analysis.</p&gt

    Implications for sequencing of biologic therapy and choice of second anti-TNF in patients with inflammatory bowel disease: results from the IMmunogenicity to Second Anti-TNF Therapy (IMSAT) therapeutic drug monitoring study

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