Forklifts under fire
MIT's entry for the Grand Challenge race is leading to a forklift for handling vital supplies in some of the most deadly places in the world.
Forklifts operate in all arenas, from the average warehouse floor to war zones such as Iraq. It is not uncommon in the more volatile territories for workers to have to abandon their vehicles three or four times a day because they have come under fire.
When supplies arrive at military outposts, forklift operators unload the pallets and put them into storage, and later load them onto trucks to take the material to where it's needed. These operators are often at risk and the regular - and quite necessary - interruptions slow their work considerably.
To counter this problem, researchers at MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) have been developing a semi-autonomous forklift that can be directed by people who are safely away from the most exposed spots.
When completed, says Matt Walter, a CSAIL post-doctoral researcher with a lead role in the project, the new robotic device will provide a safer way to handle pallet-loaded supplies of everything from truck tyres to water containers and construction materials. The new device is being designed so that it can operate outdoors on uneven terrain such as gravel or packed earth.
"A lot of the work could be automated," Walter says. "but it's a very difficult task."
The forklift is designed to operate autonomously with high-level direction from a human supervisor who could be nearby, or safely ensconced in a remote bunker. An initial 'training' phase teaches the forklift the basic layout of the storage depot facility, such as where the reception area is, where incoming supply trucks arrive with pallets ready to be stored, and where the storage areas are. The forklift can then be commanded to transport pallets within the depot.
Direction by tablet
Determining which pallets to pick up and where they need to go requires guidance from a human supervisor - at least for now. The supervisor's tablet computer, wirelessly linked to the forklift, displays the view from the forklift's forward-looking video camera. Using stylus gestures on the image, the supervisor indicates the truck to be unloaded, the pallet to be engaged next, and perhaps where on the pallet to insert the forklift tines. The supervisor also speaks to the tablet, indicating the desired destination of the target pallet.
As the system gets more sophisticated, the supervisor would need to do less and less, eventually simply gesturing and saying, "unload", for example.
Naturally, a manual override kicks in whenever an operator enters the cab, thus ensuring the forklift can carry out bespoke or complex tasks.
Research for the semi-autonomous forklift began with a small test platform rigged with forklift tines and a variety of sensors and computers. This was used for a series of indoor tests, and has now been replaced with a full-scale prototype being tested outdoors on the MIT campus.
The work is part of several projects at CSAIL focused on "the development of situational awareness for machines", explains Seth Teller, professor of computer science and engineering and project lead.
Situational awareness, Teller says, involves the use of sensing, motion, inference and memory to acquire "a model of the spatial layout of the world and its contents, to allow us to plan and move purposefully in the world". Humans develop these internal maps of their surroundings without even thinking about it, but "machines can't yet do it automatically".
In developing the robotic system, the CSAIL researchers have made extensive use of computer code developed for other projects, including the autonomous vehicle MIT entered in the 2007 DARPA Grand Challenge.
Among the tasks the robot must carry out automatically is avoiding unexpected obstacles, especially people who may be walking around in the area. That turned out to be less of a challenge than expected: "It is possible to detect moving people using laser range scanners," says Walter.
"Things get much harder if people are trying to trick the system by hiding or standing very still," Teller concedes.
The forklift project has involved the MIT, the Lincoln Laboratory, Draper Laboratory and BAE Systems, and is funded by the US Army Logistics Innovation Agency.