Robot that does nothing but climbs tree won’t inspire fear in a Time Lord as the Arduino-powered Dalek might, but building such a contraption is quite an engineering feat. An Arduino user named Ben described the process on Instructables, saying he gave the project a shot after first “dismiss[ing] the idea as beyond my skill level.”
The process of building the robot’s shell was painstaking:
I started out by creating a basic design in Sketchup. The robot was to consist of two segments, joined by a spine which could be extended or retracted. Each segment would have four legs with very sharp points as feet. To climb, the legs on the top segment would pinch together and the sharp feet would dig into the bark, securing the robot. Then the spine would be retracted, pulling up the bottom segment. The legs on the bottom segment would then grip the tree, and the top segment would release. Finally, the spine would extend, pushing the top segment upwards, and the process would repeat. The climbing sequence is somewhat similar to the way an inchworm climbs.
Since the robot was powered by an Arduino, a bit of programming was involved. Ben describes the process thusly:
To climb up a tree, the robot goes through a simple series of motions. First, the top segment grips the tree and the bottom segment releases from the tree (if necessary). Then the spine contracts, pulling the bottom segment up towards the top segment. Next the bottom segment grips the tree, and afterwards the top segment releases from the tree. Finally, the spine extends, pushing the top segment upwards, and the cycle can start over again. For ease of programming, I wrote a function corresponding to each basic motion. These are as follows:
By combining these functions in the proper order, the robot can be made to ascend or descend trees.
Here, you can see the finished robot—very slowly—climb up a tree: