Today’s virtual reality systems can create immersive visual experiences, but seldom do they enable users to feel anything — particularly walls, appliances and furniture. A new device developed at Carnegie Mellon University, however, uses multiple strings attached to the hand and fingers to simulate the feel of obstacles and heavy objects.
By locking the strings when the user’s hand is near a virtual wall, the device simulates the sense of touching the wall. Similarly, the string mechanism enables people to feel the contours of a virtual sculpture, sense resistance when they push on a piece of furniture or even give a high five to a virtual character.
The shoulder-mounted device takes advantage of spring-loaded strings to reduce weight, consume less battery power and keep costs low.
Elements such as walls, furniture and virtual characters are key to building immersive virtual worlds, and yet contemporary VR systems do little more than vibrate hand controllers.
Other researchers have used strings to create haptic feedback in virtual worlds, but typically they use motors to control the strings.
The downside to motors is they consume a lot of power. They also are heavy.
Instead of motors, the team used spring-loaded retractors, similar to those seen in key chains or ID badges. They added a ratchet mechanism that can be rapidly locked with an electrically controlled latch. The springs, not motors, keep the strings tight. Only a small amount of electrical power is needed to engage the latch, so the system is energy efficient and can be operated on battery power.
The researchers experimented with a number of different strings and string placements, eventually concluding that attaching one string to each fingertip, one to the palm and one to the wrist provided the best experience. A Leap Motion sensor, which tracks hand and finger motions, is attached to the VR headset. When it senses that a user’s hand is in proximity to a virtual wall or other obstacle, the ratchets are engaged in a sequence suited to those virtual objects. The latches disengage when the person withdraws their hand.
The entire device weighs less than 10 ounces. The researchers estimate that a mass-produced version would cost less than $50.
Tthe system would be suitable for VR games and experiences that involve interacting with physical obstacles and objects, such a maze. It might also be used for visits to virtual museums.
News Source: Eurekalert
