Work to develop an advanced humanoid robot began in 1986, when Honda established a research center focused on fundamental technologies, including humanoid robotics.
Honda engineers had to research how humans walk, using the human skeleton for reference to create a replica and have it function like a human being. In 1986, the first two-legged robot was made to walk, used by Honda engineers to establish stable walking technology, including steps and sloped surfaces.
In 1993, Honda began developing "Prototype" models ("P" series), attaching the legs to a torso with arms that could perform basic tasks. P2, the second prototype model, debuted in December 1996, using wireless techniques making it the first self-regulating, two-legged walking robot. P2 weighed 463 pounds with a height of six feet tall. In September 1997, P3 was introduced as the first completely independent bi-pedal humanoid walking robot, standing five feet, four inches tall and weighing 287 pounds.[1]