1,721,213 research outputs found
Effective backward kinematics for a 6r painting robot
No full textThe paper discusses a geometrical solution to perform the path analysis for an industrial 6R serial robot; the proposed solution represents, for the particular manipulator, an alternative to the general efficient numerical methods. The solution is conceived on the basis of a mechanism geometric decomposition, to calculate an input-output trigonometric equation in the last wrist angular joint co-ordinate. The roots are numerically singled out. By the found roots, representing the last wrist co-ordinates, all the joint sets (up to sixteen), solving the displacement analysis, are analytically worked out. The algorithm has been conceived and written to control an industrial painting robot; it has been tested and applied in production, with a worst-case running time amounting to eight milliseconds
A robotic system for underwater eco-sustainable wire-cutting
No full textThe paper deals with the design and development of a diamond wire cutting system used as end-effector of an underwater robot for removal of offshore constructions. This system fulfills the sea-bottom reclamation duties required by the environmental protection acts related to dismissing of off-shore oil plants. The research results have been achieved through extensive interaction between academia and industry, which have solved jointly scientific, technological, economic and social issues along the challenging track to eco-consistency. The, study brings forth: - the analysis of cutting using a diamond wire saw to accomplish the conceptual design of the system; - the wire micro analysis to select a suitable wire configuration. The topics are summarized highlighting the design steps, including preliminary life-cycle assessments accomplished by joining virtual reality tests and trials on an experimental bench. The robotic system has been realized and it is working satisfactory in the North Sea
Manipolatore robotico cartesiano a giunti flessibili per la automazione di operazioni su parti di piccole dimensioni
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Equilibrium analysis of multi-limbs walking and climbing robots
No full textThe paper discusses the complex problem of assessing online the static equilibrium of statically-indeterminate climbing and walking robots (CLAWARs) with quasi-static locomotion. The method proposed is general and works for whatever number of legs and ropes operated by actuated winches connecting the robot to the environment. The configuration of the robot is assigned. First, the compliance of the robot body, of the legs and the compliances of the ground and the ropes are modeled as localized elasticities. The static equilibrium problem of the resulting model is statically-determinate under the hypothesis that the foot and rope points (where the ropes are fixed to the robot body) are joined to the ground by bilateral constraints. Since these constraints are unilateral (the feet are contact points and can detach from the ground, and the ropes can become slack), it is necessary to apply an iterative solving procedure in order to solve the static equilibrium problem. The method presented in the paper is a fast and effective alternative to nonlinear analysis of a finite element model of the robot at any assigned configuration. As an example, we consider the case of the heavy-duty CLAWAR Roboclimber
Armilleye: flexible platform for underwater stereo vision
No full textThe paper describes ArmillEye, a 3-degree of freedom (DOF) flexible hybrid platform designed for agile underwater stereoptic vision. Effective telecontrol systems of remote operated vehicles require active and dexterous camera support in order to allow the operator to easily and promptly change the point of view, also improving the virtual reconstruction of the environment in difficult operative conditions (dirtiness, turbulence, and partial occlusion). The same concepts hold for visual servoing of autonomous underwater vehicles. ArmillEye was designed for this specific application; it is based on the concept of using a parallel-hybrid mechanism architecture that, in principle, allows us to minimize the ad hoc waterproof boxes (generally only for cameras) while the actuators,
fixed to the base of the mechanism, can be placed into the main body of the underwater vehicle. This concept was revealed effective and was previously proposed for underwater arms. The synthesis of ArmillEye followed the specific aims of visual telecontrol and servoing, specifying vision workspace, dexterity, and dynamics parameters. Two versions of ArmillEye are proposed: the first one with two cameras to obtain a steroptic vision by using two viewpoints (two rotational freedoms with a fixed tilt or pan axis and vergence); the second one with one camera operated to obtain a stereoptic vision by using one viewpoint (two rotational freedoms with a fixed tilt or pan axis and extrusion)
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