February 14, 2001, was a unique day at the New York Stock Exchange. In celebration of Honda's 25th year on the exchange, the day was rung in by a four foot tall humanoid robot. Honda ASIMO had been formally introduced to the west for the first time.
ASIMO is short for Advanced Step in Innovative Mobility. This robot stands almost four feet tall, and weighs 115 lbs. It looks humanoid, and is capped by a spaceman helmet with a black visor. The doctor introducing the ASIMO to the world would have mixed news for its parents. "Ten fingers, but no toes." It also carries a large "backpack", which houses the power source and CPU. But most remarkable about the ASIMO is not its appearance, but the way it moves. It lifts off with one foot, sways its hip to maintain its center of gravity, and through a controlled fall, arrested by its lifted foot, it advances towards a goal. In short, it walks like a human. When one imagines a robot moving, stiff movements are the result. One leg lifts, extends, lowers, pauses, followed by the other. ASIMO has sensors to calculate its center of balance and velocity, and knows how to move just like humans do, with a casual stride. This is remarkable to see in action.
When Honda unveiled ASIMO in Japan, spokesman Jeffrey Smith described some noble and hopeful uses for the robot. "It would provide a person without mobility the ability to move because it would be an extension of themselves. Think of the potential of how that would give that person a better life." Indeed, a remote control robot that had all of the locomotive and manipulative capabilities of a human being would truly be a boon to the disabled. Unfortunately, ASIMO is not there yet. But since his unveiling, the robot has begun being marketed for rental use in Japan, mostly for promotional uses.
A prime example of this was the Honda-sponsored 2002 Robocup. It was a mock football game, with two ASIMOs facing each other. In fact, every scored or blocked goal was set up, with the ball placed into a position by a human, and the robots carefully and painstakingly walked into position. But the motions are fluid to watch, and when the kick begins, it's hard not to imagine a human inside that suit to see the robot sway onto its hip as it draws a leg up and back, and then swings it forward into a very real kick. It "feels" right, the way it moves. The robots were programmed to pose and dance for the occasion, and it was a very amusing demonstration.
This capability for the ASIMO to maintain his balance is the result of a project begun by Honda in 1986. It wasn't until ten years later, 1996, that Honda had a prototype to show to the public, the P2. The P3 followed in 1997. Both were larger, heavier, and clumsier than the ASIMO. In fact, the small size of the ASIMO is intentional, for several reasons. Psychologically, an autonomous robot would be very intimidating. Making it smaller reduces the natural reaction to this threat. More practically, making ASIMO smaller lowers his center of gravity, making tumbles less damaging. And, it makes it easier to maneuver into tight areas.
ASIMO is currently able to walk at 1.6 kilometers per hour with Honda's "i-WALK" technology, and grasp objects with his five fingered hand. He can be controlled by a workstation, or by remote, and has recently gained voice recognition capabilities. He has "Human Joints" at the neck (providing two Degrees of Freedom), shoulder (three DOF), elbow (one DOF), wrist (one DOF), finger (one DOF), hip (three DOF), knee (one DOF), and ankle (two DOF). A degree of freedom is an axis that a joint can twist or slide along.
ASIMO is clearly mainly useful for promotions at the moment. The real advance in ASIMO over his predecessors is the continuous evaluation of his stability, and constant calculation of where to position his joints to continue or stop his motion. Previous robots had used "canned" motions, pre-recorded and played back. ASIMO's flexibility in this respect allows him to climb stairs and navigate obstacles. But seeing ASIMO in action, being carefully positioned by trained operators, clearly demonstrates his current impracticality. However, give Honda another ten years, and we may see one of ASIMO's descendents competing in the world cup against real human players.
http://www.usatoday.com/life/cyber/tech/jk112200.htm - USA Today Tech report blurb on the ASIMO
http://www.beststuff.com/article.php3?story_id=2889 - NBC report on the ASIMO
http://world.honda.com/ASIMO/ - Honda's global ASIMO web page
http://www.21stcentury.co.uk/robotics/honda_asimo_robot.asp - History of the Honda robotics program