PackBots are one of the most versatile designs from iRobot for searching an urban area for anything dangerous. Each 40-pound bot can be carried to a remote location in a backpack, and when it is deployed the PackBot can reach up to 9MPH with treads capable of traversing all kinds of complicated terrain. PackBots can even travel in water up to two meters deep if necessary, and can climb most stairs with relative ease.
The Brazilian government has entered into a $7.2 million deal with iRobot to see 30 of these machines deployed in 12 cities during the World Cup, just to make sure everyone is safe.
Given their size and maneuverability, PackBots would be able to be used as perimeter monitors where appropriate as well as rapidly deployed in the event that a backpack is found unattended or something similarly dangerous is discovered.
These bots can be remotely controlled from great distances, and offer the driver everything from HD imaging to temperature readouts while putting as few people in danger as possible. They are also small enough that there’s a good chance an excited crowd might see one and try to walk away with it during the celebrations, but I’d wager the Brazilian government has a few ideas on how to discourage that kind of behavior.