Over at Hack a Day, they pulled up an old project from 2004 by a group undergraduate Mechanical Engineering and Electrical Engineering students from Florida Atlantic University. The robotic snake, designed to inspect pipes and travel through horizontal segments, around corners, and straight up.
In order to achieve this they opted for a tri-sprung-wheel design, as seen on the right in the above image, enabling it to navigate around corners. To drive it, instead of controlling each wheel with a motor they angled the wheels about 10 degrees, similar to the design of a turbine blades but with wheels, then drove the entire thing around. This was named the “screw-drive”. After some prototyping with a screwdriver and some wood they discovered it worked out pretty good. This design came with challenges such as wiring, driving etc.
With this design the robot needed an application, IR LEDs and an IR sensitive camera was added and the robot was tethered to allow a human to control it and inspect the pipe. The robot gained position tracking using inertial navigation using an IMU created using 3 small gyroscopes bonded together using a Motorola HC12 processor.
Via: Hack a Day