August 4, 2007 Simulation has proven an effective method for training in many mission critical scenarios so it makes sense that this approach be adopted for the use of dangerous hand tools like chainsaws. To this end researchers have developed a type of hybrid virtual reality system known as the “Cybersaw” chainsaw - it looks like a chainsaw, feels like a chainsaw, sounds like a chainsaw and yet it only saws virtually. As soon as the starter is pulled, the motor starts to roar and with screaming saw in hand, the operator applies the real cutting bar to a perspex tree trunk in front of him. The virtual aspect is what the trainee sees on a projection screen behind the Perspex tree trunk - a sawhorse in the midst of an idyllic farm scene which the user can watch on the screen as the chain blade saws through the tree trunk, with the accurate simulation completed by the real feeling of resistance to the pine wood and the vibration of the saw.
To create the Cybersaw, which was developed under contract to the tool manufacturer Dolmar, researchers used a combination of complex technologies. “Mixed reality” is the term used to designate systems that combine the real world with virtual reality. Computerized vision software takes care of the optical perception by using a camera attached to the Perspex tree trunk. Via light-emitting diodes on the cutting bar, the camera determines the saw’s precise position and transmits it to the virtual image of the chainsaw that can be seen on the screen. Further extra features give the Cybersaw a completely natural feeling - the tool’s motor and carburetor have been replaced by electronics and vibration motors, with the result that holding the saw feels just like holding a real chainsaw in operation. The movable Perspex tree trunk offers the saw the resistance of the wood and the simulated sound of a whining motor allows the operator to become totally immersed in the lumberjack’s world.
Mixed reality environments are not just a gimmick. In this case they make it easier to train people learning to handle complex tools and potentially life-threatening tools in a safe environment. The research scientists are also working on the development of medical simulation environments in which health professionals can practice handling endoscopes. In this way they are not only optically immersed in a virtual patient’s body, but can also feel when they hit a vessel wall.
