The different types of military robots can be divided into two general categories based on where they are operated. Unmanned Ground Vehicles (UGVs) are robots that move around wheels or belts. These military robots can perform guard duties, investigate potentially hostile situations, and perform many other very varied tasks. The second major category is unmanned aerial vehicles (UAVs), which are mainly automated or remote controlled aircraft and helicopters. UAVs can have wingspan ranging from two to over 20 feet (0.6 to 6 meters) and are often used for aerial reconnaissance, but some are also equipped with live systems that can be used against land or air-based targets.
Military robots have been in use since around the second decade of the 20th century, when the first unmanned aircraft was developed. Early military robots also emerged during World War II, when Germany employed small remote-controlled cars known as tracked mines. These tracked mines were some of the first UGVs to appear, although they suffered from weaknesses that easily destroyed control cables. The Soviet Union also used radio controlled tank UGVs around this time. These teletanks were full size and can be operated manually as needed.
Modern military robots are used to fill a variety of niches, from reconnaissance to threat assessment. Some of the smallest UGVs used for reconnaissance operations are less than a foot (about 0.3 meters) long and can be run on either track or wheel. Medium sized UGVs are often used to both locate improvised explosive devices (IEDs) before they can injure human soldiers and enter and assess potentially hostile environments. Some of these robots are also designed to perform more specialized tasks, such as entering dangerous situations to retrieve wounded soldiers. The largest UGVs can be the size of a truck or tank and can perform many of the same role as manned versions of these vehicles.
The two most important functions performed by UAV are reconnaissance work and delivery of statutes. UAVs designed to gather intelligence can range in size from units that can fit in a backpack to others as large as manned aircraft. Small UAVs are usually used for reconnaissance because they can be brought into the field by soldiers and then sent on to assess the situation. Some of these military robots have fixed wings, although others are helicopters. Large UAVs are often used for intelligence as well, but some are also equipped with rockets, bombs and other weapons systems.
- The MQ-1 Predator drone has been widely used in anti-terror operations in the Near East and Africa.
- Robot manufacturers often use a common chassis for bomb fending off robots used by police and combat robots deployed by military forces.
- Some airborne military drones are equipped with rockets.