Researchers at Bielefeld University in Germany are working on a unique robot modeled after a stick insect, with elastic joint drives. Known as Hector, the robot was built by the the school’s Biomechatronics research group so that biologists and roboticists can test hypotheses about animal locomotion.
“The way that the elasticity in Hector’s drives acts is comparable to the way that muscles act in biological systems,” says Professor Axel Schneider, who heads the research group. The joints also make Hector easily to adapt for various kinds of of terrain.
“However, elasticity alone is not enough for Hector to be able to walk through a natural environment containing obstacles,’ says Schneider. ‘The challenge was to develop a control system that would coordinate the movements of its legs in difficult surroundings as well.”
Ultimately, the researchers opted for a control system in which Hector’s legs act somewhat independently, using minimal information from the other legs and following a few simple rules to determine when to move. A virtual version of the bot was built initially, to test various control system schemes without damaging the robot. “All sub-systems have to communicate with each other for the robot to walk without any difficulties,” says Jan Paskarbeit, who built the bot and the virtual model. “Otherwise, for example, Hector might have too many legs in the air at one time, become unstable, and fall over. Moreover, the legs have to be able to react to collisions with obstacles. We have dealt with this by implementing a reflex behaviour for climbing over objects.”
Hector will be equipped with additional functionality over the next two years, as a part of the Cluster of Excellence Cognitive Interaction Technology, including video cameras, long-range sensors, and feelers that act as touch sensors. CITEC has committed 740,000 Euros to the project, entitled ‘Embodied Interaction as a Core of Cognitive Interaction’.