Environmental Engineering Reference
In-Depth Information
Dataglove is a neoprene fabric glove with two fiber optic loops on each finger. Each loop is
dedicated to one knuckle and this can be a problem. If a user has extra large or small hands,
the loops will not correspond very well to the actual knuckle position and the user will not
be able to produce very accurate gestures. At one end of each loop is an LED and at the
other end is a photosensor. The fiber optic cable has small cuts along its length. When the
user bends a finger, light escapes from the fiber optic cable through these cuts. The amount
of light reaching the photosensor is measured and converted into a measure of how much
the finger is bent (Aukstakalnis & Blatner, 1992). Dataglove requires recalibration for each
user (Hsu, 1993). Fatigue effects and recalibration during a session are problems associated
with long term use of Dataglove (Wilson & Conway, 1991).
Fig. 5. An instrumented glove (Nintendo power glove)
Powerglove uses strain gauges to measure the flexion of each finger. A small strip of mylar
plastic is coated with an electrically conductive ink and placed along the length of each
finger. When the fingers are kept straight, a small electrical current passing through the ink
remains stable. When a finger is bent, the computer can measure the change in the ink's
electrical resistance (Aukstakalnis & Blatner, 1992). Powerglove is less accurate than the
Dataglove, and also needs recalibration for each user, but is more rugged than the
Dataglove.
The dexterous hand master (DHM) is not exactly a glove but an exoskeleton that attaches to
the fingers with velcro straps. A mechanical sensor measures the flexion of the finger.
Unlike the Dataglove and Powerglove, the DHM is able to detect and measure the side-to-
side movement of a finger. The other gloves only measure finger flexion. The DHM is more
accurate than either of the gloves and less sensitive to the user's hand size, but can be
awkward to work with (Hsu, 1993).
The main strength of the various types of gloves is that they provide a more intuitive
interaction device than a mouse or a joystick. This is because the gloves allow the computer
to read and represent hand gestures. Objects in the environment can therefore be “grasped”
and manipulated, the user can point in the direction of desired movement, windows can be
dismissed, etc (Wilson & Conway, 1991). Wilson and Conway (1991) opined that more work
is needed to expand glove's set of command gestures beyond the current simple mapping.
Another area of improvement is feedback for the user to aid hand-eye coordination and
proprioceptive feedback to let a user know when an object has been successfully grasped
(Wilson & Conway, 1991).
