Developed in the early 1990s by researchers at MIT, the Phantom was commercialised
by SensAble Technologies, and has been refined over nearly two decades. It's
a haptic interface, that essentially consists of a small robotic arm that the
user grasps as if holding a stylus. The stylus can create the sensation of touch
by exerting a small, precisely controlled force on the fingers of the user.
The arm itself is fixed down to a desk, or in the case of larger forces, is
attached to a weighted unit of its own, to discourage easy movement - all the
forces are applied to the user's hand, rather than to move the unit.
It has always been meant for interaction within virtual environments, and is fairly
similar in function to a Novint
Falcon, except that the Falcon is a 3D mouse, not a stylus input. Phantom
can be used to point, write, or manipulate with precision in a 3D environment,
just like wielding a pen and jabbing it around in the air of a room to execute
3D commands.
The Phantom is for obvious reasons, a first choice in applications that intend
to use pointing commands, sticks, or stick emulation, as the mechanics are the
same. Its limitation is that the unit only offers a single point of feedback
- pushing the pen back against the user to varying degrees. The stylus itself
has no vibratory function, limiting the interface to pure haptics, a bit like
poking a cane around a room, and getting knocked back when it hits something.
All the Phantom units, possess the following:
# Six degree-of-freedom positional sensing
# Portable design and compact footprint for workplace flexibility
# Removable stylus for end-user customisation
# Two integrated momentary switches on the stylus for ease-of-use, and end-user
customisation
# Stylus-docking inkwell for automatic workspace calibration
The smaller models possess:
# Comfortable moulded-rubber stylus with textured paint for long term use and
secure grip
# Wrist rest to maximise user comfort
# Compact workspace for ease-of-use
# Constructed of metal components and injection-moulded plastics |