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This paper presents a novel variable impedance compact compliant series elastic actuator (SEA) design for human-friendly robotics applications. The actuator design consists of a servomotor, a ball screw, a torsional spring connecting the motor and the ball screw via a pair of spur gear, and a set of translational springs connecting the ball screw nut to the output link. The translational springs with low stiffness are used to handle the low force operation and reduce nonlinear friction, output impedance, and impact. The torsional spring, being in the high speed range, has high effective stiffness and improves the system bandwidth in large force operation when the translational springs are fully compressed. This novel design overcomes the major limitations in the existing SEA design which requires a trade-off in the selection of spring constant. The new actuator design is also more compact due to the small size translational springs. We first review the merits and the limitations of current series elastic actuators. We then explain the construction and the working principle of our new design, followed by the dynamic modeling and analysis of the actuator model. Dynamic modeling on a physical implementation of the design is presented for the three conditions: (i) open loop transfer function with load end fixed, (ii) closed loop transfer function with load end fixed, and (iii) output impedance with load end free. We then conclude the paper by discussing the advantages of the actuator design over its existing counterparts and its potential applications. [ABSTRACT FROM PUBLISHER]

Within this paper, CoBoLD — short for Cone Bolt Locking Device — a bonding mechanism for modular self-reconfigurable autonomous mobile robots is presented. The docking unit is used to physically connect modular robots and/or toolboxes in order to form complex structures and robotic organisms. CoBoLD is specially designed to combine essential features like genderlessness, symmetry, high stiffness, integrated force sensors and electrical contacts, while still using a simple and low cost, easy to manufacture setup. Next to a detailed description of CoBoLDs assembly, first trails and their results are shown in this paper. CoBoLD is used at several different robotic platforms and toolboxes within the EU founded projects SYMBRION and REPLICATOR. [ABSTRACT FROM PUBLISHER]

This paper presents the relationship between spring stiffness and motor torque of a screw drive in-pipe robot that passes through a bent pipe. Their values are derived from a cross-sectional analysis of a bent pipe and a static analysis of the robot that rotates with repeating expansion and contraction of its diameter in that cross-sectional shape. To verify the validity of the analysis results, a simple and light screw drive in-pipe robot capable of moving through small pipes was developed, and experiments were performed to compare the experimentally measured torque with the analytical results. [ABSTRACT FROM PUBLISHER]

This paper presents a novel anthropomorphic metamorphic hand with a reconfigurable palm. Structure of the metamorphic hand is briefly introduced, followed by prehension analysis based on the opposition-space model. Manipulability of the hand is then studied combining the characteristic matrix equation and singular value decomposition, leading to the explicit symbolic closed-form solutions. Further, the prototype of the robotic hand is developed integrated with the initial control system, and grasping and manipulation tests are carried out to illustrate dexterity and characteristic of the new metamorphic hand. [ABSTRACT FROM PUBLISHER]