7 research outputs found

    Reliability assessment of actuator architectures for unmanned aircraft

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    First record of Epitrix hirtipennis in Hungary (Coleoptera: Chrysomelidae)

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    Epitrix hirtipennis (Melsheimer, 1847) (Coleoptera: Chrysomelidae: Galerucinae: Alticini), a leaf beetle native to North America, is recorded for the first time from Hungary. Several specimens were found on tobacco (Nicotiana tabacum L.) plantations in the eastern and central parts of the country. Its life cycle and importance as a tobacco pest are briefly discussed

    Mini Actuators for Safety Critical Unmanned Aerial Vehicles Avionics

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    The present article details the development steps and experimental results obtained during the development of smart actuators used on mini unmanned aerial vehicles (UAV). The research effort is driven by the need of developing onboard health monitoring and diagnostics units for small size UAVs to improve their reliability. In the present all small UAVs use single string avionics systems with no built in redundancy, moreover the servo actuators onboard the airplane are often commercial off the shelf (COTS) hobby components with no reliability figures, limited performance guarantees and one directional communication using analog PWM signals. The development of new servo generation focused on solving the above issues. The proposed servo actuators use the existing mechanical gearboxes and housing of the COTS components, but their power electronics, motor control hardware and software components, sensors are custom designed to fit the needs of a higher demand. The actuators with their controlling microprocessors are capable of establishing two way communication via CAN and FlexRay protocol, suitable for safety critical applications, and self diagnostics features are also hosted onboard the actuators. The development challenges and experimental results in a hardware-in-the-loop (HIL) simulator are discussed in the paper

    First record of Ophraella communa in Hungary (Coleoptera: Chrysomelidae)

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    Ophraella communa LeSage, 1986, a leaf beetle native to North America, is recorded for the first time from Hungary. Several specimens were found on a degraded meadow in the outskirts of Budapest. Its importance in suppressing its main host plant, common ragweed (Ambrosia artemisiifolia L.), is shortly discussed, as well as the potential problems it can cause in plant protection. With 5 figures

    Safety critical platform for mini UAS insertion into the common airspace

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    Impacts of livestock grazing and tree clearing on birds of woodland and riparian habitats

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    We investigated the impact of pastoral management on birds in subtropical grassy eucalypt woodland in southeastern Queensland, Australia, where the patterns of land management have made it possible to disentangle the effects of livestock grazing from those of tree clearing. We recorded changes in bird species composition, density, and relative abundance across two woodland habitat types (riparian and nonriparian) and two levels of clearing (wooded and nonwooded) and three levels of livestock grazing (low, moderate, and high) replicated over space (1000 km(2)) and time (2001-2002). We predicted that species that depend on understory vegetation would be most negatively affected by livestock grazing. A Bayesian generalized linear model showed that the level of grazing had the greatest effect when trees were present. When trees were absent, the impact of grazing was overshadowed by the effects of a lack of trees. Over 65% of species responded to different levels of grazing, and the abundance of 42% of species varied markedly with habitat and grazing. The most common response to grazing was high species relative abundance under low levels of grazing (28% of species), species absence at high levels of grazing (20%), and an increase in abundance with increasing grazing (18%). Despite having similar bird assemblages, the effect of grazing was stronger in riparian habitat than in adjacent woodland habitat. Our results suggest that any level of commercial livestock grazing is detrimental to some woodland birds, particularly the understory-dependant species, as predicted. Nevertheless, provided trees are not cleared, a rich and abundant bird fauna can coexist with moderate levels of grazing. Habitats with high levels of grazing, on the other band, resulted in a species-poor bird assemblage dominated by birds that are increasing in abundance nationally
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