After fifteen years of effort, the U.S. Army and Navy have created robotic sentries to patrol indoors and outdoors. Called MDARS (Mobile Detection Assessment Response System), it comes in two different versions. The indoor MDARS runs off batteries and contains a huge number of sensors to enable it to navigate. These include twenty electrostatic and piezoelectric sonars (both narrow- and wide-beam), a monochrome video camera, an acoustical microphone, a scanning microwave and PIR motion sensors and optical beacon sensing modules, an ultraviolet flame sensor; a gas detector, laser retroreflective proximity sensors and a scanning laser rangefinder. The outdoor version (MDARS-E) is powered by a small diesel engine and looks like a miniature jeep. This robot has all the sensors of the indoor version plus a global positioning system (GPS), and a fiber optic gyroscope (IFOG) for navigation. In addition, there is communications equipment for sending reports to the controller and onboard software that can eliminate a lot of false alarms (like mistaking animals for humans.) 

The MDARS-E (the outdoor version) has an extendable (to 28 feet) arm for it's video camera. The indoor version also uses it's sensors to literally identify and count items that are supposed to be in a warehouse, and thus alert inventory managers quickly when something disappears. This will save lots of money, as thefts in government warehouses often go unnoticed for so long that it is impossible to track down who did it. 

A small team of troops or civilian guards can supervise dozens of indoor and outdoor MDARS. Some of the troops will have to deal with maintenance, including recharging the indoor MDARS and refueling the outdoor ones. Some of the troops and guard will be an armed reaction force, to go after dangerous intruders. But most of the time the MDARS will be looking for more mundane things, like gas or water leaks, fires, broken equipment (lights, fencing or parts of buildings) or people who have had accidents. Some military warehouse sites cover hundreds of acres and have vehicle traffic just outside the fenced area. There are also people working inside the warehouse area who might have problems (falling off a ladder and getting knocked unconscious) that would normally first to detected by a guard. MDARS will make more frequent rounds, even though they cost about $250,000 each. Aside from halts for maintenance and refueling, MDARS never stops. The operator programs it to patrol an area, and that's what it will do until ordered to stop, encounters a problem or it runs out of fuel. MDARS will stop if an intruder, or dangerous situation, is spotted and will report that to the operator.

While MDARS was designed to replace security guards at established military bases, such patrolling is a common, tedious and disliked task for infantrymen in places like Iraq and Afghanistan. MDARS could actually be used in some of the more established bases in Iraq and Afghanistan right now, and may end up there. But a more rugged version, capable of handling more difficult terrain, would be a welcome addition to any infantry, tank or artillery battalion. Having robots to pull most of the guard duty lets troops get more sleep and spend more time maintaining their equipment and preparing for combat operations. This isn't just a time saver for combat troops, it's a life saver.