22,931 research outputs found
On the representations of 2-groups in {Baez-Crans} 2-vector spaces
We prove that the theory of representations of a finite 2-group
in Baez-Crans 2-vector spaces over a field of characteristic zero
essentially reduces to the theory of -linear representations of the group of
isomorphism classes of objects of , the remaining homotopy
invariants of playing no role. It is also argued that a similar
result is expected to hold for topological representations of compact
topological 2-groups in suitable topological Baez-Crans 2-vector spaces.Comment: 9 page
Design of an Anthropomorphic, Compliant, and Lightweight Dual Arm for Aerial Manipulation
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 EconomÃa y Competitividad DPI2015-71524-RMinisterio de EconomÃa y Competitividad DPI2017-89790-
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