Termites are known more for their destructive chewing than for their architectural talents. But look inside any termite mound and you’ll find an intricate network of tunnels, each designed to optimize natural air conditioning and lighting. Termites are, in fact, master builders.
How do these tiny bugs achieve such architectural genius? A combination of hardwired genetic code and environmental cues allows simple creatures like termites to produce amazing structures. A process called emergence.
Harvard University researchers have been looking more closely at emergence and applying those basic principles to robotics. Now they’ve created a team of small robots that can collectively figure out how to build a structure from blocks.
The four-year-long TERMES Project demonstrates that autonomous robots can cooperate in building a structure without any centralized computer system telling them what to do. Instead, the robots are preprogrammed with a few simple commands based on the structure that needs to be built.
A compiler developed by the Harvard team “takes any blueprint and turns it into a representation that corresponds to traffic laws for the robots to adhere to,” says TERMES Project lead Justin Werfel. “It tells them where they are allowed to go and where they can’t go.”
The robots don’t communicate with one another, but use onboard sensors to place blocks where they need to go. If a robot finds it can’t perform a certain task because it’s already been carried out by another bot, it will move on to find something else to do.
The robots may build the structure in different ways each time. If one robot fails, the others can complete the task. If more robots are added, they will work together to build the same structure.
To begin the building process, one brick is laid down as a foundation to give the robots a point of reference from which to build up the other blocks.
The termite robots were not easy to build.
Robot designer Kirstin Petersen notes that like termites the bots build structures much larger than themselves.
“Each robot is about seven inches long and four inches wide. Designing the robots was challenging because they needed to climb but also to traverse level ground,” Petersen says. “Larger whegs that provided the ability to climb higher resulted in a very bumpy construction process.”
Because the mobile robots had difficulty placing objects precisely, the team designed special foam bricks that have tongues and grooves for alignment. The bricks are held together with small magnets that make the structure stable enough for the robots to climb over.
While construction robots are nothing new, it’s the autonomy of these termite bots that makes them special.
“The real advance is the compiler that comes up with rules that tell the robots how to build what we want,” says Steve Burbeck, a North Carolina-based consultant in artificial intelligence.
Burbeck, a former IBM scientist, says that having many simple robots cooperate on projects is an exciting area for artificial intelligence. He believes they may represent an alternative to complex systems that are prone to bugs and hacking.
Werfel believes that similar systems could eventually be adopted for classic robot tasks that are “dangerous, difficult or dirty.” Such jobs might include building a levee out of sandbags in a flood zone. Eventually swarm robots might build things underwater or in space.