A Wearable Haptic Display to Present the Gravity Sensation - Preliminary Observations and Device Design.
ABSTRACT We propose a wearable ungrounded haptic display that presents a realistic gravity sensation of a virtual object. We focused on the shearing stress on the fingerpads due to the weight of the object, and found that the deformation of the fingerpads can generate a reliable gravity sensation even when proprioceptive sensation on the wrist or arm is absent. This implies that an ungrounded gravity display can be realized by reproducing fingerpad deformation. Based on our observations, we conducted evaluation tests for the device design. We first implemented the prototype device, which has a simple structure comprising dual motors, and then evaluated the recognition ability of the gravity sensation presented on the operator's finger by this method.
SourceAvailable from: Allison Okamura[Show abstract] [Hide abstract]
ABSTRACT: When grasping and manipulating objects, people are able to efficiently modulate their grip force according to the experienced load force. Effective grip force control involves providing enough grip force to prevent the object from slipping, while avoiding excessive force to avoid damage and fatigue. During indirect object manipulation via teleoperation systems or in virtual environments, users often receive limited somatosensory feedback about objects with which they interact. This study examines the effects of force feedback, accuracy demands, and training on grip force control during object interaction in a virtual environment. The task required subjects to grasp and move a virtual object while tracking a target. When force feedback was not provided, subjects failed to couple grip and load force, a capability fundamental to direct object interaction. Subjects also exerted larger grip force without force feedback and when accuracy demands of the tracking task were high. In addition, the presence or absence of force feedback during training affected subsequent performance, even when the feedback condition was switched. Subjects' grip force control remained reminiscent of their employed grip during the initial training. These results motivate the use of force feedback during telemanipulation and highlight the effect of force feedback during training.IEEE Transactions on Haptics 03/2014; 7(1):37-47. DOI:10.1109/TOH.2013.60 · 2.03 Impact Factor
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ABSTRACT: This paper proposes a tactile display providing both shear and normal feedback to the fingertip for generating three-axis tactile feedback during teleoperation of a surgical robot. The display is composed of five balloons actuated by controlling the pneumatic pressure. The implemented display is 18 mm × 18 mm × 15 mm. This size is suitable for mounting the display onto the master controls of a surgical robot. The maximum normal and shear displacements are 2 and 1.3 mm, respectively. The proposed tactile display may provide perceivable stimuli to a human finger pad in all five directions: normal, distal, proximal, radial, and ulnar. This paper also reports on the results of psychophysical measurement of the minimum perceivable movement of the developed tactile display for each of the five directions.Advanced Robotics 06/2014; 28(13). DOI:10.1080/01691864.2014.896066 · 0.56 Impact Factor
Conference Paper: Shaking a box to estimate the property of content[Show abstract] [Hide abstract]
ABSTRACT: The fact that we can guess the properties of the contents in a box or a bottle by shaking it is interesting. If this experience can be realized virtually, it would be possible to use it as a means to transmit information from a portable information appliance to a user via haptic interaction. This paper describes an approach for implementing such a device; the development of a haptic device and control system as well as the modeling and simulation of a virtual box and its contents are presented in this paper. The prototype system was evaluated, and different model parameters were experimentally tested.Proceedings of the 2012 international conference on Haptics: perception, devices, mobility, and communication - Volume Part I; 06/2012