Humanoid HRP-2 Walks on Uneven Terrain

 Many people used to think that two-legged humanoid robots with motors in their joints would never be able to walk on uneven surfaces unless they knew exactly in advance what they were stepping on and when. Drop a small pebble in its path and you could topple the robot over. Unlike in the movies, bipedal walking for robots in real life is extremely difficult.
 
 Dr. Koichi Nishiwaki and his colleagues at the AIST Digital Human Research Center have been working hard to dispel this accepted myth. GetRobo got to see a demo of the humanoid robot HRP-2  walking on pebbles, planks and tiles, at the DHRC in Tokyo.

 
 In this video, Dr. Nishiwaki is telling the robot where to go using a joystick, but other than that, the HRP-2 is on it's own. The robot has what is called an "attitude measurement sensor" on it's waist which is used to measure and control the posture as well as to estimate the absolute motion. Depending on the feedback from this sensor, a computer inside the robot generates a dynamically stable motion pattern 50 times per second. The robot checks and adjusts to this desirable motion 1,000 times per second, enabling it to remain stable and maintain it's walk.
 
 To actually reproduce the desirable motion, instead of strictly trying to control where and how the robot's foot should be placed, Dr. Nishiwaki uses a method in which the force the foot receives from the floor is checked and managed.

 

 Dr. Nishiwaki was able to make the robot remain stable even when the robot stepped on the edge of a plank (as seen in the beginning of the video) - a feat that no one else had been able to accomplish before.
 
 Still there is more to overcome before robots can really walk around your house and neighborhood. (For example, this robot can't cross it's legs to maintain a balance in certain situations like a human would.)  So when is that going to happen? 

 

 " Combined with environment recognition and path planning technologies, in 3 to 5 years, I would like to realize a humanoid robot that can walk freely indoors and on paved roads," says Dr. Nishiwaki. Now THAT'S not too far away.

 

(Photo: Dr. Nishiwaki = left = with HRP-2 and post-doctoral researcher Joel Chestnutt.

Next we would like to see HRP-2 walk on THOSE steps, don't we? Nishiwaki-san, yoroshiku onegai shimasu!)