679 resultados para Australian research
Resumo:
In this paper we present a fast power line detection and localisation algorithm as well as propose a high-level guidance architecture for active vision-based Unmanned Aerial Vehicle (UAV) guidance. The detection stage is based on steerable filters for edge ridge detection, followed by a line fitting algorithm to refine candidate power lines in images. The guidance architecture assumes an UAV with an onboard Gimbal camera. We first control the position of the Gimbal such that the power line is in the field of view of the camera. Then its pose is used to generate the appropriate control commands such that the aircraft moves and flies above the lines. We present initial experimental results for the detection stage which shows that the proposed algorithm outperforms two state-of-the-art line detection algorithms for power line detection from aerial imagery.
Resumo:
This paper outlines a feasible scheme to extract deck trend when a rotary-wing unmanned aerial vehicle (RUAV)approaches an oscillating deck. An extended Kalman filter (EKF) is de- veloped to fuse measurements from multiple sensors for effective estimation of the unknown deck heave motion. Also, a recursive Prony Analysis (PA) procedure is proposed to implement online curve-fitting of the estimated heave mo- tion. The proposed PA constructs an appropriate model with parameters identified using the forgetting factor recursive least square (FFRLS)method. The deck trend is then extracted by separating dominant modes. Performance of the proposed procedure is evaluated using real ship motion data, and simulation results justify the suitability of the proposed method into safe landing of RUAVs operating in a maritime environment.
Resumo:
Problem, research strategy, and findings: The privatization of airports in Australia included airport property development rights, regulated only by federal, not local, land use control. Airports then developed commercial and retail centers outside local community plans, resulting in a history of poor coordination of planning and reflecting strong differences between public and private values in the role of the airport. Private owners embraced the concept of an Airport City, envisioning the airport as a portal of global infrastructure, whereas public planning agencies are struggling with infrastructure coordination and the development of real estate outside of the local planning regulations. Stakeholder workshops were conducted in each of the cases where key stakeholders from airports, regulating agencies, state and local governments participated in identifying key issues impacting the planning in and around airports. This research demonstrates that if modes of infrastructure provision change significantly (such as through privatization of public services), that transformation would best be accompanied by comprehensive changes in planning regimes to accommodate metropolitan and airport interdependencies. Privatization has exacerbated the poor coordination of planning in the past, and a focus on coordination between public and private infrastructure planning is needed to overcome differences in values and interests. Takeaway for practice: Governance styles differ considerably between public agencies and private corporations. Planners should understand the drivers and value differences to better coordinate infrastructure delivery and effective planning. Research support: The Airport Metropolis Research Project under the Australian Research Council's Linkage Projects funding scheme (LP0775225).
Resumo:
This paper presents a reactive Sense and Avoid approach using spherical image-based visual servoing. Avoidance of point targets in the lateral or vertical plane is achieved without requiring an estimate of range. Simulated results for static and dynamic targets are provided using a realistic model of a small fixed wing unmanned aircraft.
Rotorcraft collision avoidance using spherical image-based visual servoing and single point features
Resumo:
This paper presents a reactive collision avoidance method for small unmanned rotorcraft using spherical image-based visual servoing. Only a single point feature is used to guide the aircraft in a safe spiral like trajectory around the target, whilst a spherical camera model ensures the target always remains visible. A decision strategy to stop the avoidance control is derived based on the properties of spiral like motion, and the effect of accurate range measurements on the control scheme is discussed. We show that using a poor range estimate does not significantly degrade the collision avoidance performance, thus relaxing the need for accurate range measurements. We present simulated and experimental results using a small quad rotor to validate the approach.
Resumo:
Australian research on Indigenous sentencing disparities of the standard of international work is somewhat recent. Contrary to expectations based on international research, Australian studies generally have not found Indigenous offenders to be treated substantively more harshly than non-Indigenous offenders in similar circumstances. However, this research has primarily focused on adult higher courts, with little attention to lower courts and children’s courts. In this article, we examine whether Indigeneity has a direct impact on the judicial decision to incarcerate for three courts (adult higher, adult lower, children’s higher court) in Queensland. We found no significant differences in the likelihood of a sentence of incarceration in the higher courts (adult and children’s). In contrast, in the lower courts, Indigenous defendants were more likely to be imprisoned than non-Indigenous defendants when sentenced under statistically similar circumstances.
Resumo:
Recent attention in education within many western contexts has focused on improved outcomes for students, with a particular focus on closing the gap between those who come from disadvantaged backgrounds and the rest of the student population. Much of this attention has supported a set of simplistic solutions to improving scores on high stakes standardized tests. The collateral damage (Nichols & Berliner, 2007) of such responses includes a narrowing of the curriculum, plateaus in gain scores on the tests, and unproductive blame games aimed by the media and politicians at teachers and communities (Nichols & Berliner, 2007; Synder, 2008). Alternative approaches to improving the quality and equity of schooling remain as viable alternatives to these measures. As an example in a recent study of school literacy reform in low SES schools, Luke, Woods and Dooley (2011) argued for the increase of substantive content and intellectual quality of the curriculum as a necessary means to re-engaging middle school students, improving outcomes of schooling and achieving a high quality, high equity system. The MediaClub is an afterschool program for students in years 4 to 7 (9-12 year old) at a primary school in a low SES area of a large Australian city. It is run as part of an Australian Research Council funded research project. The aim of the program has been to provide an opportunity for students to gain expertise in digital technologies and media literacies in an afterschool setting. It was hypothesized that this expertise might then be used to shift the ways of being literate that these students had to call on within classroom teaching and learning events. Each term, there is a different focus on digital media, and information and communication technology (ICT) activities in the MediaClub. The work detailed in this chapter relates to a robotics program presented as one of the modules within this afterschool setting. As part of the program, the participants were challenged to find creative solutions to problems in a constructivist-learning environment.
Resumo:
Automated airborne collision-detection systems are a key enabling technology for facilitat- ing the integration of unmanned aerial vehicles (UAVs) into the national airspace. These safety-critical systems must be sensitive enough to provide timely warnings of genuine air- borne collision threats, but not so sensitive as to cause excessive false-alarms. Hence, an accurate characterisation of detection and false alarm sensitivity is essential for understand- ing performance trade-offs, and system designers can exploit this characterisation to help achieve a desired balance in system performance. In this paper we experimentally evaluate a sky-region, image based, aircraft collision detection system that is based on morphologi- cal and temporal processing techniques. (Note that the examined detection approaches are not suitable for the detection of potential collision threats against a ground clutter back- ground). A novel collection methodology for collecting realistic airborne collision-course target footage in both head-on and tail-chase engagement geometries is described. Under (hazy) blue sky conditions, our proposed system achieved detection ranges greater than 1540m in 3 flight test cases with no false alarm events in 14.14 hours of non-target data (under cloudy conditions, the system achieved detection ranges greater than 1170m in 4 flight test cases with no false alarm events in 6.63 hours of non-target data). Importantly, this paper is the first documented presentation of detection range versus false alarm curves generated from airborne target and non-target image data.
Resumo:
The Australian Research Council (ARC) Innovative Products Project aims to facilitate project innovation by exploring means to improve the diffusion of innovative products to road and bridge projects. It adopts a highly novel approach to achieve this end, developing three different ways of viewing the problem: (1) as a relational governance issue, (2) as an absorptive capacity issue and (3) as a knowlege intermediation issue. This report presents teh results of teh first phase of a three phase fieldwork program.
Resumo:
The Cross-Entropy (CE) is an efficient method for the estimation of rare-event probabilities and combinatorial optimization. This work presents a novel approach of the CE for optimization of a Soft-Computing controller. A Fuzzy controller was designed to command an unmanned aerial system (UAS) for avoiding collision task. The only sensor used to accomplish this task was a forward camera. The CE is used to reach a near-optimal controller by modifying the scaling factors of the controller inputs. The optimization was realized using the ROS-Gazebo simulation system. In order to evaluate the optimization a big amount of tests were carried out with a real quadcopter.
Resumo:
The aim of this paper is to implement a Game-Theory based offline mission path planner for aerial inspection tasks of large linear infrastructures. Like most real-world optimisation problems, mission path planning involves a number of objectives which ideally should be minimised simultaneously. The goal of this work is then to develop a Multi-Objective (MO) optimisation tool able to provide a set of optimal solutions for the inspection task, given the environment data, the mission requirements and the definition of the objectives to minimise. Results indicate the robustness and capability of the method to find the trade-off between the Pareto-optimal solutions.
Resumo:
The feasibility of using an in-hardware implementation of a genetic algorithm (GA) to solve the computationally expensive travelling salesman problem (TSP) is explored, especially in regard to hardware resource requirements for problem and population sizes. We investigate via numerical experiments whether a small population size might prove sufficient to obtain reasonable quality solutions for the TSP, thereby permitting relatively resource efficient hardware implementation on field programmable gate arrays (FPGAs). Software experiments on two TSP benchmarks involving 48 and 532 cities were used to explore the extent to which population size can be reduced without compromising solution quality, and results show that a GA allowed to run for a large number of generations with a smaller population size can yield solutions of comparable quality to those obtained using a larger population. This finding is then used to investigate feasible problem sizes on a targeted Virtex-7 vx485T-2 FPGA platform via exploration of hardware resource requirements for memory and data flow operations.
Resumo:
This paper presents a novel evolutionary computation approach to three-dimensional path planning for unmanned aerial vehicles (UAVs) with tactical and kinematic constraints. A genetic algorithm (GA) is modified and extended for path planning. Two GAs are seeded at the initial and final positions with a common objective to minimise their distance apart under given UAV constraints. This is accomplished by the synchronous optimisation of subsequent control vectors. The proposed evolutionary computation approach is called synchronous genetic algorithm (SGA). The sequence of control vectors generated by the SGA constitutes to a near-optimal path plan. The resulting path plan exhibits no discontinuity when transitioning from curve to straight trajectories. Experiments and results show that the paths generated by the SGA are within 2% of the optimal solution. Such a path planner when implemented on a hardware accelerator, such as field programmable gate array chips, can be used in the UAV as on-board replanner, as well as in ground station systems for assisting in high precision planning and modelling of mission scenarios.
Resumo:
This article outlines the integration of robotics in two settings in a primary school. This initiative was part of an Australian Research Council project which was undertaken at this school. The article highlights how robotics was integrated in a technology unit in a year four class. It also explains how it was embedded into an after-school program which catered for students from years five to seven. From these experiences further possibilities of engaging with robotics are also discussed.
Resumo:
This paper summarises the achievements of the Smart Skies Project, a three-year, multi-award winning international project that researched, developed and extensively flight tested four enabling aviation technologies: an electrooptical mid-air collision avoidance system, a static obstacle avoidance system, a mobile ground-based air traffic surveillance system, and a global automated airspace separation management system. The project included the development of manned and unmanned flight test aircraft, which were used to characterise the performance of the prototype systems for a range of realistic scenarios under a variety of environmental conditions. In addition to the collection of invaluable flight data, the project achieved world-firsts in the demonstration of future automated collision avoidance and separation management concepts. This paper summarises these outcomes, the overall objectives of the project, the research and the development of the prototype systems, the engineering of the flight test systems, and the results obtained from flight-testing.