Do you know a sensor (not metal detector by coil) to detect metal and plastic mine under ground?

Question

i want to make a Minedetecting robot thath should detect metal and metal_plastic mine under ground.I can not use just electromagnetic sensor and.

Answer 1

There are other means used to detect mines.

As you mention, metal detectors are one way, but many mines are designed out of plastic and other materials specifically to avoid detection by these means (the whole point of a mine, after all, is to not be removed easily by the enemy). And even metal detectors probably produce a hundred or more false positives as they encounter just stray bits of metal and shrapnel for every real mine they detect - and for a person finding mines they have to treat each one with equal seriousness.

The other qualities mines have that are used for detection are basically fourfold, and each has their own problems:

The first relies on the fact the explosives are not stable. Almost all of them will eventually leak nitrous oxide, which can then be detected by genetically engineered critters. This method of detection produces false positives too - some natural lifeforms produce nitrous oxide on their own, though usually in much smaller amounts than explosives would produce. Further, the key word in this method is 'eventually'. New, well-made explosives aren't going to leak nitrous oxide for some time.

Another means of possible detection involves the fact that explosives have a comparatively high concentration of nitrogen when compared to most natural things. If you bombard nitrogen with neutrons, it can be forced to undergo a nuclear process with gives signs that can be detected. However, most sources of radiation that might be used for neutron bombardment are perhaps more dangerous then the mines themselves if an accident should occur. Research is being conducted into safer sources, for use in airports and the like, but nothing has come up yet.

Perhaps the most obvious characteristic of a mine is that it explodes when you step on it. So one way of finding them is to drive something heavy over it that won't be harmed the way a person would if he stepped on one. This method, unfortunately, seldom explodes enough mines for the field not to be considered dangerous any more, and some armies have developed countermeasures such as mixing anti-tank mines with anti-personnel ones and by separating the pressure sensor from the charge so that important things might still be destroyed from the explosion.

The last method may be one of the more widely used ones, but also the most difficult to incorporate into a robot - smell. Rats, dogs, and dolphins are all used to detect mines with their sensitive perceptions of the world around them. Some commercially designed mine-removal robots have even come to resemble these creatures in appearance as well. Farfetched as it may seem, there have been machines developed that can sense certain smells, so if you could quantify the exact 'odor' of a mine you might be able to design a robot which could sense them in this way, cutting out lots of training and some of the other problems that come from dealing with animals. Such devices are fairly experimental right now, however.

No great solutions that I can see, but lots of potential if you get just the right edge. I can only hope you succeed in your venture! Good luck!