April 1, 2006 A new invention allows users to explore virtual worlds while moving around safely in their real physical environment. Wearing a virtual-reality helmet, users walk inside a rotating, hollow sphere, while a computer responds by changing the visuals displayed in the helmet. The sphere could find applications in education, firefighter training, and entertainment.
SEATTLE--A new virtual reality device lets you move around your virtual environment by actually walking, running, jumping and rolling without bumping into objects in the room.
Step inside the hollow ball and you can go virtually anywhere. It's Kate Peterson's first time inside the VirtuSphere virtual-reality device. She says, "You kind of have to take a leap of faith, but once you get there it's a lot of fun, for sure."
Alexey Palladin, former CEO of VirtuSphere, Inc., in Redmond, Wash., says, "If you can put a person inside the sphere and have the sphere rotate, you will have limitless possibilities of traveling in virtual reality."
In this case, it's to the site of Moscow's bid for the 2012 Olympic games. A head-mounted display gives Kate a virtual environment. Sensors under the sphere send info on its speed and direction to a computer, while Doppler ultrasound tracks Kate's every move.
Suzanne Weghorst, a senior research scientist at the Human Interface Technology Lab at the University of Washington in Seattle, says, "It solves a problem that we have, you know, struggled with for awhile in virtual reality research, and that is: How do you get people to move around in virtual environments in a natural way?"
By combining psychology and computer science, researchers are studying various options for VirtuSphere. Training for firefighters, exercise and rehab are all possibilities. "You could make some progress using this that you'd be afraid to do perhaps in real life," Weghorst says.
Video games are also in the sphere's future, as is education. Instead of walking through Moscow, perhaps students could experience walking on the moon.
Some scientists argue VirtuSphere and other virtual locomotive devices are immature to use as mainstream products, mainly because of the risks of moving around in a rotating device without seeing where your feet are going.
BACKGROUND: VirtuSphere is the first all-directional virtual reality device. It is an 8.5-foot hollow ball. The user steps into the ball wearing a wireless, head-mounted virtual display, and can walk, jump, roll, crawl or run in any direction over virtually unlimited distances -- without encountering real-world physical obstacles. Possible applications include rehabilitation, exercise, gaming and other forms of entertainment, museum exhibits, virtual travel, fire prevention training, and even science education, since the VirtuSphere would enable a simulation of walking on the Moon.
HOW IT WORKS: The head-mounted display provides the user with the virtual environment. Sensors under the sphere provide the speed and direction of the user's movement to the computer running the simulation. So as the user moves, the VirtuSphere ball rolls, sending coordinates to the computer. The computer then evaluates this information and relays it back to the user's display, changing the view. Users can also interact with objects in virtual space using a manipulator called a haptic interface.
THE DOPPLER EFFECT: Doppler radar, an ultrasound device, helps detect precisely how much the sphere is moving so the user can be tracked step by step. Doppler radar uses a well-known effect called the Doppler shift. A moving object that's emitting light can seem to change color depending on whether it's moving toward or away from you. Light emitted by a moving object seems to increase in frequency, and looks more blue, if it is moving toward the observer; if the object is moving away from us, it will be shifted toward the red end of the spectrum. The same is true of sound: sound waves reflected by something moving away from the source change to a lower frequency, while those from an object moving toward a source change to a higher frequency. That's why a train whistle will sound higher as it approaches a platform and then become lower in pitch after it passes you and moves away. Doppler radar sends out radio waves that bounce off objects in the air, such as raindrops or snow crystals, and then measures how much the frequency changes in returning radio waves to better determine wind direction and speed.
WHAT IS VIRTUAL REALITY: The term "virtual reality" is often used to describe interactive software programs in which the user responds to visual and hearing cues as he or she navigates a 3D environment on a graphics monitor. But originally, it referred to total virtual environments, in which the user would be immersed in an artificial, three-dimensional computer-generated world, involving not just sight and sound, but touch as well. Devices that simulate the touch experience are called haptic devices. Touch is vital to direct and guide human movement, and the use of haptics in virtual environments simulates how objects and actions feel to the user. The user has a variety of input devices to navigate that world and interact with virtual objects, all of which must be linked together with the rest of the system to produce a fully immersive experience.
The Human Factors and Ergonomics Society contributed to the information contained in the TV portion of this report.