A computer controller levitated by magnets provides a new way to physically experience virtual objects.
The "maglev" system has benefits over more mechanical haptic controllers computer interfaces that stimulate the user's sense of touch and its inventors are now working to commercialising the technology.
Haptic technology has uses ranging from remote medical breast checks and exploring distant lands, to recreating the feel of fabrics.
But most haptic interfaces to date rely upon gloves or robotic arms to provide feedback to a user. The complex mechanics involved increases weight and friction that can make it difficult to provide a natural feel.
To solve that, Ralph Hollis and colleagues at Carnegie Mellon University, Pittsburgh, US, developed a haptic device with just one moving part (see video, top right).
A bowl with electromagnets concealed below its base contains a levitating bar that is grasped by a user and can be moved in any direction. The magnets exert forces on the bar to simulate the resistance of a weight, or a surface's resistance or friction. LEDs on the bar's underside feed back its position to light sensors in the bowl.
This approach has "huge potential", says Anthony Steed, a haptics researcher at University College London, UK. "This system gets rid of the mechanical linkages that are a major constraint on most haptic devices."
The maglev interface can exert enough force to make objects feel reassuringly solid, says Hollis, resisting as much as 40 newtons of force before it shifts even a millimetre.
That's enough to feel the same as a hard surface and better than most existing interfaces, he says. "Current devices feel very mushy, so it's hard to simulate a hard surface.
The device can track movements of the bar as small as two microns, a fiftieth the width of a human hair. That's important for feeling very subtle effects of friction and texture," says Hollis.
And it can exert and respond to all six degrees of freedom of movement moving along or rotating about each of the three dimensions of space (forward/backwards, left/right, up/down).
Stephen Brewster, of the Interactive Systems Group at the University of Glasgow, says the maglev approach is totally different from existing systems.
"It offers things that other devices just can't do the high forces, low friction, low inertia, and six degrees of freedom."
After working on a series of prototypes since 1997, Hollis has started a company called Butterfly Haptics to market the technology. The first six second-generation versions of the device will soon be shipped for testing to a consortium of several US and Canadian universities.
The system will be showcased at the IEEE Symposium on Haptic Interfaces for Virtual Environments and Teleoperator Systems, which opens on 13 March.
By Remainz
Tue Mar 04 21:46:23 GMT 2008
Why does the video look like it was shot in 1997?By Bob
Wed Mar 05 06:44:10 GMT 2008
In order to resist with so much force, of course, the device has to be nailed down or made as part of the desk. This isn't nearly as practical as a freestanding mouse or video game controller. This could be very useful for certain modeling but is undoubtedly expensive and bulky. By poking around YouTube I saw another video by the same group (also late 90s) which showed that the controller is an entire 'desk sized cabinet' to house all the parts.All comments should respect the New Scientist House Rules. If you think a particular comment breaks these rules then please use the "Report" link in that comment to report it to us.
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