nivek@rover.ri.cmu.edu (Kevin Dowling) (07/04/90)
I've been collecting and collating information on snake-like robots and serpentine manipulators recently for a project I've recently undertaken. My initial aim to produce a comphrehensive survey and develop insights into these mechanisms from previous works. Fitz is right about continuous ground contact in his post. However this may be an advantage for providing leverage for force application or lifting body parts off the ground. Crawling or sliding mechanisms that can traverse through narrow spaces has tremendous applications in many areas. Hirose at Tokyo Institute of Technology is Mr. Snake, in my opinion, he's carefully studied biomechanisms and built many instances of flexible locomotors. Many of his papers are available in the literature. There are several people in Zoology who study limbless locomotion and I've contacted people and gathered some info in this area. There are disagrements however about the exact mechanisms that allow snakes to propel themselves. Research in this area goes back decades and there is much information in this area. Modes include standard undulations, concertina, and sidewinding and another mode involves propagating waves down the skins. Interesting stuff. Other studies in tentacles and elephant trunks are also out there. In medicine there are several groups that have worked on active endoscopes that provide doctors with information about colon problems. Some of these papers are not for the squeamish! There have been perhaps two dozen serpentine manipulator projects. These are devices with far greater DOF's than the 6DOF standard industrial manipulators. This types can be broken down into flexible and rigid link mechanisms. These projects date back from the late 50's to several projects going on today here and in Japan. I have found little work in Europe with the exception of some modeling of Elephant trunk kinematics,, rumors of a French cascaded parallel-mechanism (stewart-platforms), the Spine, and a project once done at University College of London. Wilson at Duke has an interesting varient using flexible legs to walk! I'm very interested in further information on these mechanisms if you know of any. I can track down even vague pointers if you know something of them! nivek aka : Kevin Dowling Senior Research Engineer net : nivek@rover.ri.cmu.edu Robotics Institute tel : (412) 268-8830 Carnegie Mellon University Pittsburgh, PA 15213