I’ve written about the curious mechanism behind walking before, and that time it was done in the context of robotics, too. In short, biological legs are the highly efficient products of a complex engineering challenge posed to nature. And when we design mechanisms with legs, we need to learn from the best.

Today I saw a video that made me revisit this topic. It’s a compilation of robots participating in the DARPA Robotics Challenge Finals, held last weekend in Los Angeles.

The challenge is the latest in a series of competitions funded by the US Defence Advanced Research Project Agency. It was launched after the nuclear disaster in Fukushima, Japan, and had a focus on disaster recovery. The goal was to accelerate robotics research so that we can soon have disaster recovery assistance from robust, dexterous and autonomous robots capable of entering areas that humans cannot. In the final test, robots from 23 participating teams had to go through an eight-task course that saw them driving, walking through rubble, turning valves and other tasks that might be required in a disaster situation. They had one hour to complete the course without any human assistance.

Curiously, they fell down quite a bit, although reports say that most were fine after being picked up and dusted off.

This compilation was taken of the various falls that occurred on Day One of the finals. Funny enough, there were far fewer falls on the previous day during the rehearsal. It may seem comical and cringey at the same time, but it also highlights something we don’t often think about – walking is hard. Humans move their feet without much thought, because we don’t have to. But this is an evolved capacity, not one created by design.

These robots are highly sophisticated machines, but carrying around all that sophistication and ability also requires lots of metal, electronics, and other heavy parts. Striking the right balance becomes part of the challenge.

The team who took home the $2 million prize came from South Korea – Team Kaist’s robot DRC-Hubo scored eight points out of eight, and spent 44 minutes on the track. You can see it driving through the obstacle course in the video below, and also hear what its developers have to say about bipedal walking.