The marvellous limp

Steve told me a story about Honda's ASIMO robot, I don't know if it's true or perhaps applies to another humanoid robot, but it sounds entirely plausible. The robot was being shown off at some expo or another; in particular, its ability to climb stairs. Halfway up, one of the servos in a leg froze, and it fell over.

Then I thought: wouldn't it be amazing if someone designed a robot that could limp?

This isn't as stupid as it sounds at first blush. Limping, when you think about it, is an amazing behaviour. It's the ability to circumvent almost any non-critical musculoskeletal damage or defect in the legs and pelvis (chassis?) and keep going.

It is not something we think about consciously, which is amazing. If you get a rock in your shoe and don't have time to take it out, you will automatically alter your gait to put less pressure on that part of the foot. You can sprain your ankle and thereby limit its range of motion and the load which that leg can bear, or you can even fracture an important structural element like the foot or the tibia and if the situation is important enough, you will keep walking.

Even something as small and stupid as an ant, if you break off one of its legs, will go where it wants to go instead of wobbling around in a circle as a six-legged robot would.

OK...I just Googled it...robot limping has been looked into. We really need to know more about this if robots are ever to function usefully "in the wild". ASIMO will not be useful for taking care of housebound old folks if itself is also prone to falling down the stairs and lying there helpless.