11,496 research outputs found

    Innovative solution for reducing the run-down time of the chipper disc using a brake clamp device

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    Wood-chippers are widely used machines in the forestry, urban and agricultural sectors. The use of these machines implies various risks for workers, primarily the risk of contact with moving and cutting parts. These machine parts have a high moment of inertia that can lead to entrainment with the cutting components. This risk is particularly high in the case of manually fed chippers. Following cases of injury with wood-chippers and the improvement of the technical standard (Comit\ue9Europ\ue9en de Normalisation-European Norm) EN 13525: 2005 + A2: 2009, this technical note presents the prototype of an innovative system to reduce risks related to the involved moving parts, based on the \u201cbrake caliper\u201d system and electromagnetic clutch for the declutching of the power take-off (PTO). The prototype has demonstrated its potential for reducing the run-down time of the chipper disc (95%) and for reducing the worker\u2019s risk of entanglement and entrainment in the machine\u2019s feed mouth

    Design of an Anthropomorphic, Compliant, and Lightweight Dual Arm for Aerial Manipulation

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    This paper presents an anthropomorphic, compliant and lightweight dual arm manipulator designed and developed for aerial manipulation applications with multi-rotor platforms. Each arm provides four degrees of freedom in a human-like kinematic configuration for end effector positioning: shoulder pitch, roll and yaw, and elbow pitch. The dual arm, weighting 1.3 kg in total, employs smart servo actuators and a customized and carefully designed aluminum frame structure manufactured by laser cut. The proposed design reduces the manufacturing cost as no computer numerical control machined part is used. Mechanical joint compliance is provided in all the joints, introducing a compact spring-lever transmission mechanism between the servo shaft and the links, integrating a potentiometer for measuring the deflection of the joints. The servo actuators are partially or fully isolated against impacts and overloads thanks to the ange bearings attached to the frame structure that support the rotation of the links and the deflection of the joints. This simple mechanism increases the robustness of the arms and safety in the physical interactions between the aerial robot and the environment. The developed manipulator has been validated through different experiments in fixed base test-bench and in outdoor flight tests.Unión Europea H2020-ICT-2014- 644271Ministerio de Economía y Competitividad DPI2015-71524-RMinisterio de Economía y Competitividad DPI2017-89790-
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