Virtual reality bytes – military uses of VR
Key text
This topic is sponsored by the Defence Science and Technology Organisation and the Australian Government Department of Education, Science and Training.
The Australian Defence Force is blending the real and the virtual to train and equip defence personnel cost-effectively and safely.
Most parents would prefer their children to turn off the Playstation and get on with their homework. But the skills learnt by playing interactive computer games might just make them the ideal military commander of the future. Tomorrow’s warfare will be increasingly fought on digital terrain where commanders will need Playstation skills – the ability to process information rapidly and to solve problems interactively.
Virtual reality is used by the military to train personnel, help reduce information overload, increase understanding of military processes, and test and improve new technologies.
What is virtual reality?
Virtual reality (VR) is – in short – an artificial environment created by computers, in which people can immerse themselves and feel that this artificial reality really does exist. The appeal of virtual reality is that people can experience an environment which may not exist in real life or which may not normally be available to them because of factors such as cost or safety.
Immersion and interactivity
We have all experienced some form of VR. Watching a movie is a low-grade VR experience. For a couple of hours we immerse ourselves in an artificial environment, even though we keep in mind that the movie is not reality.
Virtual environments are more believable when they engage all our senses. Take cabin rides in amusement parks as an example. People in the cabin watch a movie of a virtual roller coaster ride through some hair-raising landscape. The jerking, shunting, and rolling motion of the cabin makes the experience seem much more real than the view from a passive seat at the movies.
The key to sophisticated VR is interactivity. Visitors to a VR environment not only have to be able to navigate their way around, they also need to be able to influence the course of events in their environment.
Plugging in to virtual worlds – interface devices
To enter a virtual world, a visitor must use special interface devices that transmit the sight, sounds and sensations of the artificial world. These devices also need to transmit information about what the user is doing back to the computer controlling the virtual environment.
Commercial flight simulators employ a number of interface devices. The simulators consist of mock cockpits fitted out with real instruments, mounted on motion platforms that pitch and roll. Thousands of pilots have been trained in skills such as night flying, without the cost or hazards of using real aircraft.
Another interface device is a special helmet known as a head-mounted display (HMD). In front of each eye is a small screen made from a liquid-crystal display – each screen presents a slightly different view to create a three-dimensional effect of depth for the viewer. The HMD also contains a motion tracker to monitor both the orientation of the head and the direction in which the user is looking.
Using information from the HMD, the computer calculates images of the virtual world to match the direction in which the user is looking, and displays these images on the small display screens. The computer has to generate new images at least ten times a second so that the view does not appear too jerky and does not lag behind the user's movements.
An interface device known as the sensory glove can create a realistic sense of touch in the virtual world. The glove transmits information such as the position of the user’s hand and movement of each finger to the computer, which then instructs the glove to create the appropriate sensation, such as tapping a finger on a hard surface or picking up a glass of water. With increasing computer power, the sensory glove could eventually be developed into a body suit to create a sense of touch over the whole body.
Smart helmets
The next generation of display systems for military aircraft will include HMDs. One HMD application is helmet-mounted sights for advanced air-to-air missiles. At present a pilot has to manoeuvre the aircraft to point in the general direction of the target before releasing a missile. Helmet-mounted sights track the direction in which the pilot is looking and pass this information to the missile control system. All the pilot has to do is look at the target and fire the missile.
The Defence Science and Technology Organisation (DSTO), part of Australia's Department of Defence, is testing prototype HMDs in its advanced flight simulation centre. This allows the new HMD technology to be 'flown' and evaluated by a pilot without leaving the safety of the ground. The simulator consists of a cockpit placed at the centre of a domed room, with the virtual landscape projected onto the inside surface of the dome. The simulation is so real it is not unusual for pilots to emerge from the dome bathed in sweat and the adrenalin still pumping.
Virtual battlespaces
Traditionally, military command has been seen more as an art than a science. Commanders in the field have often had to rely on intuition and past experience, because of their lack of information regarding the strength, movement and fire power of the opposing force.
The opposite is usually the case for today’s commander. Information pours in from video surveillance, satellite imagery, electronic sensors and other sources of intelligence. Commanders now face the problem of information overload.
A solution to this problem is being investigated by computer scientists at the Virtual Environments and Simulation Laboratory at the Australian Defence Force Academy in Canberra. The project, known as 3-D Immersive Military Perspective, uses computer graphics and virtual reality to create an interactive 3-D view of the battlefield terrain. The commander is presented with a simplified visual representation of actual battlefield conditions, so that decisions can be made much faster with less room for error (Box 1: Synthetic environments).
DSTO is also exploring the use of virtual environments to enhance military decision-making at its Future Operations Centre Analysis Laboratory in Adelaide. Commanders, assisted by a panel of artificially intelligent virtual advisors, are able to explore the virtual battlespace and experiment with alternative courses of action.
Virtually no limits
As computer processing power increases and even more realistic graphics are developed, the simulated environments produced by virtual reality systems will become even more believable. The technology developed from military uses of virtual reality is finding application in many walks of life. For example,
- medical students operate on virtual patients rather than real people;
- architects take people on a virtual tour of their dream home before finalising the design;
- people attend conferences and social events without having to board a plane; and
- chat rooms mean much more than just email notice boards.
Twenty years ago, few imagined that personal computers would soon be found in almost every home, classroom and office. In twenty years' time, virtual reality may be just as central to our lives. Immersing ourselves in a virtual environment of our choice may become as commonplace as turning on the TV.
Posted March 2002.