1,140 research outputs found
Position / force control of systems subjected to communicaton delays and interruptions in bilateral teleoperation
Thesis (Master)--Izmir Institute of Technology, Mechanical Engineering, Izmir, 2012Includes bibliographical references (leaves: 65-68)Text in English; Abstract: Turkish and Englishix, 76 leavesTeleoperation technology allows to remotely operate robotic (slave) systems located in hazardous, risky and distant environments. The human operator sends commands through the controller (master) system to execute the tasks from a distance. The operator is provided with necessary (visual, audio or haptic) feedback to accomplish the mission remotely. In bilateral teleoperation, continuous feedback from the remote environment is generated. Thus, the operator can handle the task as if the operator is in the remote environment relying on the relevant feedback. Since teleoperation deals with systems controlled from a distance, time delays and package losses in transmission of information are present. These communication failures affect the human perception and system stability, and thus, the ability of operator to handle the task successfully. The objective of this thesis is to investigate and develop a control algorithm, which utilizes model mediated teleoperation integrating parallel position/force controllers, to compensate for the instability issues and excessive forcing applied to the environment arising from communication failures. Model mediation technique is extended for three-degrees-of-freedom teleoperation and a parallel position/force controller, impedance controller, is integrated in the control algorithm. The proposed control method is experimentally tested by using Matlab Simulink blocksets for real-time experimentation in which haptic desktop devices, Novint Falcon and Phantom Desktop are configured as master and slave subsystems of the bilateral teleoperation. The results of these tests indicate that the stability and passivity of proposed bilateral teleoperation systems are preserved during constant and variable time delays and data losses while the position and force tracking test results provide acceptable performance with bounded errors
Contact identification for assembly-disassembly simulation with a haptic device
Assembly/Disassembly (A/D) simulations using haptic devices are facing
difficulties while simulating insertion/extraction operations such as removing
cylinders from holes. In order to address this configuration as well as others,
an approach based on contact identification between components is presented in
this paper. This approach can efficiently contribute either to a new A/D
simulation preparation process relying on two types of shape representations
(mesh and CAD NURBS models), or directly to the real time simulation process
when it is performed with 6D haptic devices. The model processing pipeline is
described and illustrated to show how information can be propagated and used
for contact detection. Then, the contact identification process is introduced
and illustrated through an exampl
New Geometric Data Structures for Collision Detection
We present new geometric data structures for collision detection and more, including: Inner Sphere Trees - the first data structure to compute the peneration volume efficiently. Protosphere - an new algorithm to compute space filling sphere packings for arbitrary objects. Kinetic AABBs - a bounding volume hierarchy that is optimal in the number of updates when the objects deform. Kinetic Separation-List - an algorithm that is able to perform continuous collision detection for complex deformable objects in real-time. Moreover, we present applications of these new approaches to hand animation, real-time collision avoidance in dynamic environments for robots and haptic rendering, including a user study that exploits the influence of the degrees of freedom in complex haptic interactions. Last but not least, we present a new benchmarking suite for both, peformance and quality benchmarks, and a theoretic analysis of the running-time of bounding volume-based collision detection algorithms
A framework for robotized teleoperated tasks
"Premio al mejor artĂculo presentado en ROBOT 2011" atorgat pel Grupo de RobĂłtica, VisiĂłn y Control de la Universidad de Sevilla, la Universidad Pablo Olavide i el Centro Avanzado de TecnologĂas Aeroespaciales.Teleoperation systems allow the extension of the
human operatorâs sensing and manipulative capability into a
remote environment to perform tasks at a distance, but the
time-delays in the communications affect the stability and
transparency of such systems. This work presents a teleoperation
framework in which some novel tools, such as nonlinear
controllers, relational positioning techniques, haptic guiding
and augmented reality, are used to increase the sensation
of immersion of the human operator in the remote site.
Experimental evidence supports the advantages of the proposed
framework.Award-winningPostprint (published version
Hybrid Rugosity Mesostructures (HRMs) for fast and accurate rendering of fine haptic detail
The haptic rendering of surface mesostructure (fine relief features) in dense triangle meshes requires special structures, equipment, and high sampling rates for detailed perception of rugged models. Low cost approaches render haptic texture at the expense of fidelity of perception. We propose a faster method for surface haptic rendering using image-based Hybrid Rugosity Mesostructures (HRMs), paired maps with per-face heightfield displacements and normal maps, which are layered on top of a much decimated mesh, effectively adding greater surface detail than actually present in the geometry. The haptic probeâs force response algorithm
is modulated using the blended HRM coat to render dense surface features at much lower costs. The proposed method solves typical problems at edge crossings, concave foldings and texture transitions. To prove the wellness of the approach, a usability testbed framework was built to measure and compare experimental results of haptic rendering approaches in a common set of specially devised meshes, HRMs, and performance tests. Trial results of user testing evaluations show the goodness of the proposed HRM technique, rendering accurate 3D
surface detail at high sampling rates, deriving useful modeling and perception thresholds for this technique.Peer ReviewedPostprint (published version
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