In Aaron Johnson’s “Robot Design & Experimentation” class at CMU, teams of students have a semester to layout and build an experimental robotic system based on a theme. For spring 2019, that theme was “Bioinspired Robotics,” which is definitely one of our favorite kinds of robotics—animals can do all forms of crazy things, and it’s always a lot of fun watching robots try to match them. They pretty never succeed, of course, but even basic imitation can lead to robots with some unique capabilities.
 
One of the projects from this year’s course, from Team ScienceParrot, is a new version of RHex called T-RHex (pronounced T-Rex, like the dinosaur). T-RHex comes with a tail, but more importantly, it has tiny tapered toes, which help it grip onto rough surfaces like bricks, wood, and concrete. It’s able to climb its way up very steep slopes, and hang from them, relying on its toes to keep itself from falling off.
 
T-RHex’s toes are called microspines, and we’ve seen them in all kinds of robots. The most famous of these is definitely JPL’s LEMUR IIB (which wins on sheer microspine volume), although the concept goes back at least 15 years to Stanford’s SpinyBot. Robots that use microspines to climb tend to be fairly methodical at it, since the microspines have to be involved and disengaged with care, limiting their non-climbing mobility. T-RHex manages to perform many of the same sorts of climbing and hanging maneuvers without losing RHex’s ability for quick, efficient wheel-leg (wheg) locomotion.
 
If you look directly at T-RHex walking in the video, you’ll notice that in its standard forward gait, it’s sort of walking on its ankles, rather than its toes. This means that the microspines aren’t engaged most of the time, so that the robot can use its regular wheg motion to get around. To engage the microspines, the robot moves its whegs backwards, meaning that its tail is perhaps coming out of its go. But since all of T-RHex’s potential is automated in nature and it has no active sensors, it doesn’t really need a head, so that’s fine.
 
The highest climbable pitch that T-RHex could take care of was 55 degrees, meaning that it can’t, yet, overcome vertical walls. The researchers were most shocked by the robot’s potential to cling to surfaces, where it was perfectly happy to hang out on a slope of 135 degrees, which is a 45 degree overhang (!). I have no idea how it would ever reach that kind of position on its own, but it’s nice to know that if it ever does, its spines will keep doing their job.



This article is originally posted on Tronserve.com