Hector, the stick insect-inspired robot built by a research team at Bielefeld University in Germany that we first covered in 2011, could be forgiven for feeling lonely as the only one of its kind in world, but has lately been too busy learning to walk to worry on its unique status. It is hoped that Hector, which stands for Hexapod Cognitive autonomously Operating Robot, will benefit not only roboticists but also biologists interested in animal movement.
Most six-legged robots tend to walk with a tripod or another fixed leg gait. Hector, however, has a "free gait," meaning it has flexible leg control to deal with rough surfaces with each leg making its own decision of when and where to move. Called "active posture adaptation," it means using its sensors, Hector can figure out how to surmount basic obstacles, such as a wooden platform.
Modeled on a stick insect, Hector features a very light exoskeleton made from carbon-fibre-reinforced plastic (CFRP). Along with its many sensors and short-range cameras, the unique robot has 18 passive electric joints that mimic the way muscles act.
"The way that the elasticity in Hector’s drives acts is comparable to the way that muscles act in biological systems," says Professor Dr. Axel Schneider. "However, elasticity alone is not enough for Hector to be able to walk through a natural environment containing obstacles. The challenge was to develop a control system that would coordinate the movements of its legs in difficult surroundings as well."
"All sub-systems have to communicate with each other for the robot to walk without any difficulties," says researcher Jan Paskarbeit. "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 behavior for climbing over objects."
Hector can thus behave rather like an actual insect and make decisions about how to best proceed through its immediate surroundings. The researchers say that in the future, Hector could also serve as a platform for biologists and roboticists to test hypotheses about animal locomotion.
A virtual prototype was also built to test things out without risking damage to the robot. The scientists also studied the motion of real stick insects to understand the control mechanisms in the insect’s nervous system and turn them into viable computer models.
Hector is still something of an incomplete stick insect robot, but its creators say by 2017 it will be much improved as it is part of a major project at Cluster of Excellence Cognitive Interaction Technology (CITEC). The team is already created a prototype with two lateral cameras and two tactile feelers, and is currently working on attaching far-range sensors to Hector's "head."
The video below shows Hector strutting his stuff.
Source: Bielefeld University
