281 research outputs found
System description document for the Anthrobot-2: A dexterous robot hand
The Anthrobot-2 is an anatomically correct, fully functioning robot hand. The number of fingers, the proportions of the links, the placement and motion of the thumb, and the shape of the palm follow those of the human hand. Each of the finger and thumb joints are servo-controlled. The Anthrobot-2 also includes a two-degree-of-freedom wrist. The entire package, including wrist, hand, and actuators, will mount on the ends of a variety of industrial manipulators. A patent has been applied for on the design. The Anthrobot-2 will be useful in tasks where dexterous manipulation or telemanipulation are required
Autonomy Infused Teleoperation with Application to BCI Manipulation
Robot teleoperation systems face a common set of challenges including
latency, low-dimensional user commands, and asymmetric control inputs. User
control with Brain-Computer Interfaces (BCIs) exacerbates these problems
through especially noisy and erratic low-dimensional motion commands due to the
difficulty in decoding neural activity. We introduce a general framework to
address these challenges through a combination of computer vision, user intent
inference, and arbitration between the human input and autonomous control
schemes. Adjustable levels of assistance allow the system to balance the
operator's capabilities and feelings of comfort and control while compensating
for a task's difficulty. We present experimental results demonstrating
significant performance improvement using the shared-control assistance
framework on adapted rehabilitation benchmarks with two subjects implanted with
intracortical brain-computer interfaces controlling a seven degree-of-freedom
robotic manipulator as a prosthetic. Our results further indicate that shared
assistance mitigates perceived user difficulty and even enables successful
performance on previously infeasible tasks. We showcase the extensibility of
our architecture with applications to quality-of-life tasks such as opening a
door, pouring liquids from containers, and manipulation with novel objects in
densely cluttered environments
Holdable Haptic Device for 4-DOF Motion Guidance
Hand-held haptic devices can allow for greater freedom of motion and larger
workspaces than traditional grounded haptic devices. They can also provide more
compelling haptic sensations to the users' fingertips than many wearable haptic
devices because reaction forces can be distributed over a larger area of skin
far away from the stimulation site. This paper presents a hand-held kinesthetic
gripper that provides guidance cues in four degrees of freedom (DOF). 2-DOF
tangential forces on the thumb and index finger combine to create cues to
translate or rotate the hand. We demonstrate the device's capabilities in a
three-part user study. First, users moved their hands in response to haptic
cues before receiving instruction or training. Then, they trained on cues in
eight directions in a forced-choice task. Finally, they repeated the first
part, now knowing what each cue intended to convey. Users were able to
discriminate each cue over 90% of the time. Users moved correctly in response
to the guidance cues both before and after the training and indicated that the
cues were easy to follow. The results show promise for holdable kinesthetic
devices in haptic feedback and guidance for applications such as virtual
reality, medical training, and teleoperation.Comment: Submitted to IEEE World Haptics Conference 201
マルチ スケール キノウ ヲ ユウスル コウソク ジドウ マイクロ マニピュレーション システム
Ebubekir Avci, Chanh-Nghiem Nguyen, Kenichi Ohara, Yasushi Mae, Tatsuo Arai, Analysis and suppression of residual vibration in microhand for high-speed single-cell manipulation, International Journal of Mechatronics and Automation, 2013-Vol.3, No.2, pp.110-11
Development of Object-Based Teleoperator Control for Unstructured Applications
For multi-fingered end effectors in unstructured applications, the main issues are control in the presence of uncertainties and providing grasp stability and object manipulability. The suggested concept in this thesis is object based teleoperator control which provides an intuitive way to control the robot in terms of the grasped object and reduces the operator\u27s conceptual constraints. The general control law is developed using a hierarchical control structure, i.e., human interface I gross motion control level in teleoperation control and fine motion control/object grasp stability in autonomous control. The gross motion control is required to provide the position/orientation of the Super Object (SO), and the sufficient grasping force to the fine motion control. Impedance control is applied to the gross motion control to respond to the environmental forces. The fine motion control consists of serially connecting the finger in position control and the Fingertip Actuation System (FAS) in force control. The FAS has a higher bandwidth response than does the finger actuation system and operates near the center of its joint range. The finger motion controller attempts not only to track the displacement of the FAS but also to provide an FAS centering action. Simulation experiments in both gross and fine motion control are performed. The integrated gross / flue motion control is implemented using the planar configuration of PUMA 560. The results show that the desired contact force can be maintained in the direction of FAS motion. The mathematical proof of system stability and the extension to spatial systems are required to complete the research
Air Force research in human sensory feedback for telepresence
Telepresence operations require high quality information transfer between the human master and the remotely located slave. Present Air Force research focuses on the human aspects of the information needed to complete the control/feedback loop. Work in three key areas of human sensory feedback for manipulation of objects are described. Specific projects in each key area are outlined, including research tools (hardware), planned research, and test results. Nonmanipulative feedback technologies are mentioned to complete the advanced teleoperation discussions
Design, development and evaluation of Stanford/Ames EVA prehensors
Space Station operations and maintenance are expected to make unprecedented demands on astronaut EVA. With Space Station expected to operate with an 8 to 10 psi atmosphere (4 psi for Shuttle operations), the effectivness of pressurized gloves is called into doubt at the same time that EVA activity levels are to be increased. To address the need for more frequent and complex EVA missions and also to extend the dexterity, duration, and safety of EVA astronauts, NASA Ames and Stanford University have an ongoing cooperative agreement to explore and compare alternatives. This is the final Stanford/Ames report on manually powered Prehensors, each of which consists of a shroud forming a pressure enclosure around the astronaut's hand, and a linkage system to transfer the motions and forces of the hand to mechanical digits attached to the shroud. All prehensors are intended for attachment to a standard wrist coupling, as found on the AX-5 hard suit prototype, so that realistic tests can be performed under normal and reduced gravity as simulated by water flotation
Towards a Twisted String Actuated Haptic Device: Experimental Testing of a 2-D Virtual Environment and Teleoperation Interface
In the article, a first stage implementation of a haptic device towards a complete 3-D workspace twisted-string actuated haptic interface is discussed. In the present work, a 2-D setup is presented, with the aim of preliminarly testing the behaviour of this novel haptic system, especially with respect to the adopted cable-based actuation solution. In particular, the component descriptions, kinematics of the planar device and the controller for teleoperation purposes are illustrated. Results regarding the behaviour of the system in rendering a virtual environment and in a robot teleoperation scenario with haptic force feedback are reported. The experimental outcomes show that the designed and implemented system is suitable for teleoperation with haptic interfaces, providing positive perspectives for the realization of the fully functional 3-D haptic interface in the future work
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