Unimate: The First Industrial Robot, From GM's Die Casting to Carson

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In the 1960s a 4,000 pound, five-axis hydraulic arm rolled onto the stage of The Tonight Show with Johnny Carson. It poured a beer without spilling, knocked a golf ball into a cup, waved a conductor's baton, and played an accordion. The machine was the Unimate, the world's first industrial robot, and the stunt was calculated. Its makers, inventor George Devol and Joseph Engelberger of Unimation, wanted the public to see a precise, obedient helper instead of the mechanical monster of science fiction.

This episode tells the biography of that machine, beginning in the spring of 1961 at a General Motors plant in Ewing Township, New Jersey. There the Unimate took over die casting, pulling blistering hot parts from molds amid toxic fumes and the constant risk of burns and amputation. Putting the robot in the most hazardous job on the line framed it as a shield for workers. Making it function without microchips or software took even more ingenuity.

• Devol's background was in optical sound recording for motion pictures and magnetic sensing, and his 1954 patent for Programmed Article Transfer applied the same idea to positioning machinery.
• The robot's memory was a rotating drum whose dents tripped microswitches and opened hydraulic valves, much like the pins of a music box, and later drums stored positions magnetically.
• Operators programmed it by hand, dragging the arm through each step in a learning mode, an early form of what is now called imitation learning.
• A fixed encoder array let the arm compare its position with its target and slow down before stopping, so its own momentum would not tear the joints apart.
• The Unimate inspired a line of robots of the same name in DC Comics and was inducted into the Robot Hall of Fame in 2003.