How does that robot help the EOD unit? Digging up the explosive?
Very close. They usually are used for delicate operations very close to a live bomb, such as when they attempt to remotely defuse the bomb. This serves as an advantage because the robot weighs a whole lot less than a Person or a Vehicle and therefore won't set off most of the 'pressure sensitive' type bombs or IEDs. Also, if the Bomb/IED is of the 'remote detonation' type, then the Robot is a lot less valuable of a target than a Soldier or Vehicle and detonating the bomb anyway will give away the position of the bomber (via Radio Waves. A lot of people fail to realize that EOD units are equipped to intercept those. They have a bit of a time if the bomb was hardwired however.). Therefore, it's more likely that the bomber will allow the bot through. The bomber has a chance of getting away, but there's one less bomb.
If they can't disarm the bomb/IED, then the EOD crew will usually give the Robot a small bomb of their own to take very close to the bomb in order to cause a 'controlled detonation' of the bomb/IED. After the robot has returned to safety, of course.
In many cases, the robot quickly (after one or two close brushes with large explosions) becomes a 'part of the team' when speaking to the EOD guys and is treated accordingly by them. In fact, it's not unheard of, or even that uncommon, for the EOD crews to have a small funeral for a Bomb-bot that 'died in the line of duty'. Seriously, these can become very tearful events. I've seen many a manly man cry very manly tears, over a robot. Even people that don't take the robot that seriously can easily be drawn up into it. Speaking from experience. I very nearly cried.