Honda ASIMO

What ASIMO is

ASIMO is a humanoid robot that Honda announced on 20 November 2000 in Tokyo. The name is short for Advanced Step in Innovative Mobility.^[1] The machine shown that day stood 1,200 mm tall and weighed 43 kg.^[1]

A body sized for a human household

The height was a design decision, not an attempt to copy a person exactly. Honda chose 120 cm as the optimal height for operating household switches, reaching doorknobs, and working at tables and benches.^[1] In other words, the robot was dimensioned around the furniture and fittings people already use.

The 2000 ASIMO had 26 degrees of freedom in total: 2 in the head, 10 in the arms, 2 in the hands and 12 in the legs.^[1] A degree of freedom is one independent direction in which a joint can move, so the more of them a limb has, the more positions it can take. Nearly half of ASIMO's were in the legs, which had to carry the whole body and shift its weight from foot to foot. Power came from a 38.4V/10AH nickel-metal-hydride battery, and walking speed ranged from 0 to 1.6 km/h — a slow, deliberate pace.^[1]

Balance and changes of direction

Walking on two legs is mostly a problem of not falling over. Honda combined "predicted movement control" with its earlier walking control know-how, which allowed the robot to change direction smoothly rather than stopping to turn.^[1] Its sensors included a 6-axis foot sensor, plus a gyroscope and a deceleration sensor in the torso.^[1] A gyroscope reports how the body is turning; a foot sensor of this kind measures the forces between the sole of the foot and the floor. Readings like these tell the control system where the body's weight is and how fast it is moving, which is what a two-legged machine needs in order to keep itself above its feet.

Rental, then new generations

In 2001 Honda introduced ASIMO for a rental business.^[2] A year later it announced a new ASIMO with intelligence technology that could interpret human postures and gestures and move independently in response.^[2] That shifted the emphasis from walking to reacting to people nearby.

Physical capability kept growing. Honda said the 2005 ASIMO could run at 6 km/h and run in a circular pattern.^[2] By 2011, Honda said ASIMO could run at 9 km/h, hop on one leg, walk over uneven surfaces, open a bottle and pour water into a paper cup, and use sign language.^[2] Running, hopping and crossing uneven ground all demand faster balance correction than plain walking; opening a bottle and pouring water demand fine control of the hands and arms.

The end of the run

ASIMO's last regular demonstration took place at Honda's headquarters in Tokyo on 31 March 2022.^[3] Honda said it would focus instead on remotely controlled avatar robots.^[3]

Between the 2000 announcement and that final demonstration, the public image of the machine changed: from a two-legged platform that demonstrated stable walking, to a robot meant to operate in the same spaces as people, reading their gestures, running, and handling objects such as bottles and cups.^[2]