939 research outputs found

    Radar-Only Off-Road Local Navigation

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    Off-road robotics have traditionally utilized lidar for local navigation due to its accuracy and high resolution. However, the limitations of lidar, such as reduced performance in harsh environmental conditions and limited range, have prompted the exploration of alternative sensing technologies. This paper investigates the potential of radar for off-road local navigation, as it offers the advantages of a longer range and the ability to penetrate dust and light vegetation. We adapt existing lidar-based methods for radar and evaluate the performance in comparison to lidar under various off-road conditions. We show that radar can provide a significant range advantage over lidar while maintaining accuracy for both ground plane estimation and obstacle detection. And finally, we demonstrate successful autonomous navigation at a speed of 2.5 m/s over a path length of 350 m using only radar for ground plane estimation and obstacle detection.Comment: 7 pages, 17 figures, ITSC 202

    Planning Sensitivities for Building Contingency Robustness and Graph Properties into Large Synthetic Grids

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    Interest in promoting innovation for large, high-voltage power grids has driven recent efforts to reproduce actual system properties in synthetic electric grids, which are fictitious datasets designed to be large, complex, realistic, and totally public. This paper presents new techniques based on system planning sensitivities, integrated into a synthesis methodology to mimic the constraints used in designing actual grids. This approach improves on previous work by explicitly quantifying each candidate transmission line’s contribution to contingency robustness, balancing that with geographic and topological metrics. Example synthetic grids build with this method are compared to actual transmission grids, showing that the emulated careful design also achieves observed complex network properties. The results shed light on how the underlying graph structure of power grids reflects the engineering requirements of their design. Moreover, the datasets synthesized here provide researchers in many fields with public power system test cases that are detailed and realistic

    "I want it all, and I want it now" : lifetime prevalence and reasons for using and abstaining from controlled Performance and Appearance Enhancing Substances (PAES) among young exercisers and amateur athletes in five European countries

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    Doping use in recreational sports is an emerging issue that has received limited attention so far in the psychological literature. The present study assessed the lifetime prevalence of controlled performance and appearance enhancing substances (PAES), and used behavioral reasoning theory to identify the reasons for using and for avoiding using controlled PAES in young exercisers across five European countries, in the context of the "SAFE YOU" Project. Participants were 915 young amateur athletes and exercisers (M = 21.62; SD = 2.62) from Cyprus, Germany, Greece, Italy, and UK who completed an anonymous questionnaire that included measures of self-reported use of controlled PAES, as well as reasons for using and not using controlled PAES. The results of the descriptive analyses demonstrated that almost one out five exercisers in the sample had a previous experience with controlled PAES. Higher prevalence rates were found in Greece and Cyprus and lower in Italy. The most frequently reported reasons for using controlled PAES included achieving the desired results faster; pushing the self to the (physical) limits; and recovering faster after exercise/training. Furthermore, the most frequently reported reasons for not using controlled PAES involved worry about any possible adverse health effects; not feeling the need for using them; and wanting to see what can be achieved naturally without using any controlled PAES. The findings of the present study indicate that the use of controlled PAES is fast becoming a crisis in amateur sports and exercise settings and highlight the need for preventive action and concerted anti-doping education efforts. © 2017 Lazuras, Barkoukis, Loukovitis, Brand, Hudson, Mallia, Michaelides, Muzi, Petróczi and Zelli

    Location-Dependent Impacts of Resource Inertia on Power System Oscillations

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    Inertial responses are seen by the system as the injection or withdrawal of electrical energy, corresponding to a change of frequency. The inertia of a machine primarily contributes to the power system transient stability. Oscillations are always present in the bulk power system due to the electromechanical nature of the grid. Poorly damped oscillations may cause system instability. Thus, this paper aims to study inertia\u27s impacts on system primary frequency response, in particular on system oscillation modes. Both transient stability simulations and modal analysis are performed to provide insights into the extent to which inertia and its location influence the system oscillation behavior. Simulation results using both a small-scale test system and a large-scale synthetic network dynamic model are presented to verify the locational impacts of resource inertia
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