Virtual reality heals mind and body

Riders of the virtual horse can select different image settings: sound effects change to match drive system speed.

Osaka, Japan -Two attributes of horseback riding--physical exercise for the lower back and upper leg muscles, plus soothing images of the countryside--combine in a new therapy tool for the disabled and elderly. Developed by Matsushita Electric Works in partnership with the Japanese National Rehabilitation Center for the Disabled, the Virtual Reality Horse-Therapy System simulates the motion of horseback riding as well as the scenery in which one rides.

Primary components include the drive unit, control system, and VR simulation, complete with sound effects. Six AC 400- Watt Panasonic Minas Series belt-driven servo motors, each with a capacity of supporting a 200-kg force, drive screw rods attached to the horse torso.

The AC servo motors provide precise positioning, creating motion. The horse's mouth holds an aluminum plate embedded with sensors; pulling on the reins signals the drive system to decrease speed or turn the horse in a desired direction.

Six high-speed cameras, focused on the saddle of a real horse, were used to photograph motion. Collected data was then transformed into input data for the drive system, creating real 3D motion. "To make the system more practical and yet simulate a real riding experience," says Project Leader Ryoji Nakajima, "we reduced motion amplitude to one-third of its original value." Once the virtual reality images were shot, the audio portion was added using a standard sound blaster system.

Closed-loop feedback allows user control over the horse's motion.

"The toughest part of the design," recalls Nakajima, "was coordinating the visual images with the drive system. At the time we were developing the system, no image control technology existed to change the direction of the viewer's eye position while riding to make the ride real." Overcoming this problem, he says, involved reducing the number of VR image frames by 50% for better control of the entire system.

Next step in the design cycle? "Make the system more affordable," Nakajima says. The virtual horse is presently installed at a rehabilitation center in Hayashima city.

For more information about VR systems from Matsushita: Circle 538

Matsushita pioneers VR efforts

VR graphics and CFD analysis permit simulation of a fire evacuation situation.

In recent years, the Human Media Technology Group at Matsushita Electric Works, under the management of Kazuya Sawada, has focused on the development of virtual reality systems for better design. One example: a room navigation system that will enable engineers to design home appliances on the web.

Called RoomNavi, the system allows users to walk into the rooms of a house in a virtual 3D setting with the ability to change viewpoints by backing up, moving forward or to the side, or rotating images. Because appliances can be arranged or placed in any part of the room, engineers can view dimensional design constraints.

"The unique feature of this system," notes Ryoji Nakajima, RoomNavi team leader, "is that it is fully accessible through an ordinary notebook PC connection without the need of a high-speed connection environment." Currently available only in Japan, an English version is expected. In the future, Nakajima adds, engineers will be able to input CAD data directly into RoomNavi to further reduce product development time and cost.

In another project, engineers at Matsushita have successfully created a virtual reality system that can be used to design urban environments. The VR system utilizes a new 6.8m semi-spherical screen with six front-type projectors generating 3D images as wide as 180°in the horizontal direction, and 90°in the vertical direction.

"The new screen system has a much wider angle of vision and involves much less distortion than previous systems," Sawada claims. "This allows an increased number of viewers to see the images in an immersed stereo setting."

Sawada cites a recent simulation involving 100 virtual humans, a virtual alarm system, and CFD analysis to simulate a fire evacuation situation. "We were able to show that the design of an underground hall was safe for emergency evacuation."

Both the Urban Environment and Room Navigation systems were developed with funding from MITI.