At first glance the challenge looks deceptively simple. Have your robot climb a short set of stairs, take a few more steps, then descend a similar set of stairs. In real life it quickly turns into a major challenge - one that might drive you over the edge trying.
At RoboGames 2007 in San Francisco last week, many of the competitors attempted the stair climbing challenge, and several of them achieved very respectable results, as you can see from the video below.
Keeping a humanoid robot balanced on a flat, level surface for walking is a challenge, but that's only the beginning when it comes to stair climbing.
Not only do you have to keep the robot balanced while shifting it's weight back and forth from foot to foot, you also have to tilt it forwards then backwards while lifting the robots body on one foot, then the other.
To make matters even more challenging, even if you're lucky enough to make to the top of the stairs, you still have to walk several steps forward, then descend the down staircase - without any external help to get the feet positioned correctly for the attempt.
Rob Farrell of Farrell Robotics readies Zog for an attempt at stair climbing.
The RoboGames android stair climbing competition is based on the ROBO-ONE Special competition rules for the event as of a few years ago. In Japan, as the robots abilities improved dramatically, stair climbing was eliminated as a separate event and incorporated instead as a part of the extremely difficult obstacle course event.
The stair climbing challenge dimensions
At RoboGames 2007, some of robots (and their builders) did very well, while others needed a lot more practice before they will be ready to take it on. Here's a video of the robots attempting the challenge.
Update: It's important to note that most of the builders that attempted the stair climb at RoboGames 2007 didn't have much time to prepare in advance. Only one robot, Kugai, had officially entered the event online, though the RoboGames organization cross-registered all the androids across all their events which gave everyone a great chance to try new challenges. With only an hour or so to practice under the pressure and tension of the event, we think that all the competitors did surprisingly well, and will do much better next time around.