My talk today will be a little different. I'm going to describe a microprocessor application which doesn't exist, at least not yet. Now you may accuse me of crossing the frontier of vaporware into the unexplored territory of vaporsystems. I'm doing it because I believe it may be possible to find an engineering solution to what is generally viewed as a political, military, or humanitarian problem.
Solving the problem presents challenges in robot mechanics and mobility, sensors and sensor fusion, autonomous or semi-autonomous navigation, and even low-cost pyrotechnics. Yet this is a project you can build in your garage, test in your back yard, and where demonstrated success can lead to substantial funding and personal renown.
War-weary Germans learned of the development of the V-2, the first operational ballistic missile, in their movie newsreels of January 21, 1945.
No newsreel in early 1945 spoke of the preparations at the Trinity site in the New Mexico desert leading to the successful test of the first fission bomb on July 16, 1945.
The progeny of these secret weapons, the intercontinental missile and the thermonuclear warhead, would in large part define the international arena for most of our lives.
The same week Berliners learned of the V-2, recently liberated Parisians saw the first glimpse of another German secret weapon, the Bakelite plastic land mine, discovered by Allied troops advancing after the failure of the German counter-offensive in the Battle of the Bulge.
And fifty years later, that's exactly where we are today. In Angola, Cambodia, Afghanistan and dozens of other countries, people are probing the ground with knives to find and remove plastic land mines, often laid decades before in forgotten battles.
As the threat from ballistic missiles and nuclear weapons seems to be diminishing, the land mine remains the terror weapon of choice in conflicts around the globe. Land mines have killed and maimed more people than ballistic missiles and nuclear weapons combined. They are one of the bitterest legacies of the war.
Estimates of the number of mines currently in the ground range from 85 to more than 200 million. Another 100 million are in inventory, waiting to be laid.
Most of these mines cost less than 5 dollars.
There are more than 70,000 land mine amputees in Angola today, one out of every 140 people, and the number is rising at a rate of more than 2000 a year. Fewer than 10% ever receive prosthetic limbs.
In combat, engineers work to clear a path to permit troops and vehicles to advance. Heavily-armoured tanks that flail the ground with chains have been employed for this since D-day--they simply ride out the explosions, and every now and then you replace the chains.
After the battle, the priority is de-mining roads to permit resupply. The path is narrow and well-defined, and the terrain is amenable to wheeled and tracked vehicles. Other mined areas are dealt with simply by posting a "Danger--Mines" sign.
You have to cover a wide area, including all kinds of terrain, and you need a high confidence all the mines have been neutralised before sending your kids out to work in the fields.
Arms control initiatives can be viewed as attempts to raise the cost of laying a mine by restricting supply. Nobody believes it's possible to substantially close the gap that way.
So, we're faced with what appears to be an insuperable economic problem. If we were lawyers or politicians, we'd just give up but, hey, we're engineers. Let's hack.
It's amazing what you can accomplish with clever engineering riding the back of a multi-decade technological trend. Ten years ago were we marveling, "Memory is free." Might we, in a few years, say the same thing about mine clearance?
Why not explore the other end of the scale? Smaller, cheaper, and smarter seems to work awfully well in a variety of situations. Why not in the minefield? In particular, might it be possible to build a small, light, inexpensive robot which could find buried mines and, in some manner, dispose of them?
Instead of a huge tank rumbling around, occasionally detonating a mine, why not a bunch of rat robots sniffing out the mines somehow? Rats and rabbits don't set off mines--if they did, the mine problem would quickly take care of itself.
The more I thought about it, the more I became convinced it just might be possible.
But here's a job crying out for cheap, lightweight, highly mobile, all-terrain robots which, if you managed to build them, could immediately be put to the test and set to work all around the globe with an immediate humanitarian payoff. They could be tested without expensive environment simulators, deployed without enormous launch costs, and refined in the field with the quick turn-around effective engineering requires.
Feedback from the environment is essential to rapid evolution. Sudden, violent death is a highly effective and time-proven form of negative feedback.
We should be able to make a system, though, that can be operated by local talent with no more training than it takes to play a Nintendo game. Perhaps we can enlist a game designer to make it as addictive--Super Mario Minerat. Well, probably not.
Cleared terrain, especially agricultural land, has immediate economic value. This translates into compensation for the operator.
Fully manual operation, like a remote-controlled lawnmower, isn't desirable, since we need a high level of confidence that all mines have been detected. We need verification of a complete sensor sweep of the area, and that implies enough navigation capability to delegate some of the responsibility to the robot. Besides, automating wherever possible reduces the risk of errors due to boredom in a human operator.
Rabbits mark the division between light- and heavyweight approaches. If rabbits set off mines, most mines would be quickly exploded. Population doubling time in rabbits is such that loss to mines would be a minor cause of death. So, as long as we have less impact on the terrain than a rabbit, we can dispense with heavy armour. We don't even need real-time sensor analysis; this may make some approaches, like synthetic aperture radar, feasible.
The design should use only components available worldwide and free of all export restrictions. Notwithstanding policies of certain countries, I don't believe Iraqi and Iranian kids should have their legs blown off because their governments happen to be out of favour.
We should certainly feel free to bet on ever-increasing processor power. A molasses-slow compute-bound design will probably run as fast as the mechanics permit by the time it's in wide use in the field.
Mountain bikes demonstrate, at least in the hands of lunatic riders, the ability to negotiate a broad variety of terrain. Their components may be applicable to our slower, more risk-averse robots.
In the First World, agricultural land is not highly valued; over the last 50 years, despite population growth, marginal farmland in Europe has reverted to forest. But within the lifetime of the younger people in this room, the world's population will double from 5 to 10 billion, and most of those new people will be in the Third World. It's too late to stop it or slow it--the parents of the 10 billion are already maturing. Human dignity and survival in this world will require an agriculture, both intensive and extensive, surpassing anything in the human experience. That means lots of arable land, and lots of that land is mined and unusable today.
When we budget, we often assume salaries are the largest component. Twelve hours from now, at dawn in Angola, people will walk into the fields to clear mines by hand. They earn 50 dollars a month doing this dangerous work. That is ten times the salary of teacher.
Knowledge of and access to high-technology components are almost nonexistent. We need to encapsulate the high tech stuff into a box that a bicycle mechanic can turn into a Minerat.
Local materials, local manufacturing, and local manpower are essential to making this work. We must design with that in mind.
Better to blow them where they lie. Explosions are entirely acceptable in mined terrain, and provide unambiguous confirmation of destruction.
We should be able to develop a shotgun shell-sized shaped charge, costing much less than one dollar in million lots, which will detonate a mine in place.
The cheaper we make the charges, the more false positives we can tolerate. That reduces the performance criterion for the sensor suite and detection capability. We should let economics decide this--90% false detections may be the optimal point, and we shouldn't be offended if it works out that way.
Conversely, if we find a cheap, lightweight, and reliable sensor and discover we can't build a suitable robot, we could sweep it over the ground at the end of a long boom.
Several kinds of sensors appear promising. Plastic mines don't entirely contain the characteristic odour of nitrate-based explosives. Trained dogs have demonstrated the ability to detect buried mines, even metal mines in many cases. Dogs are impractical for area clearance due to the extensive training, lack of attention span, and the need for a human handler, but they do show that mine detection though vapor emission is feasible. Development of micro-machined silicon sensors capable of detecting picowatt exothermic reactions may, in conjunction with a suitable catalyst, yield effective sensors at chip prices.
Monopulse or ultrawideband radar has demonstrated the ability to image more than one metre into most soil, plenty deep enough to detect mines. Lawrence Livermore has licensed such technology and it is currently being developed for commercial applications as mundane as stud finders.
Synthetic aperture radar has also demonstrated adequate ground-penetrating capability. While existing systems are large, it may be possible to develop a hybrid system with a large transmitting antenna and individual local receiving antennas on the robots.
Talking about vaporsystems isn't nearly as satisfying as demoing hardware. In a couple of years, maybe we'll be able to stage another Asilomar first--the first-ever All-Robot Exploding Easter Egg hunt. It'd be great if three or four entries were inspired by this talk.