Scheinman's arm goes to JPL
At IJCAI-73 Boris Dobrotin of the Jet Propulsion Laboratory and Victor Scheinman of the Stanford AI Project described the manipulator of JPL's robot research programme, built on the design of Stanford's Hand-Eye project: six degrees of freedom (two rotary, one linear, three rotary), a reach of up to 52 inches, a lift of about 5 pounds, a full motion in about 5 seconds, and six DC torque motors with harmonic drives on the four inner rotary joints. The arm is entirely under computer control: a person gives only gross-level commands.
Why it matters
The electric arm Scheinman designed at Stanford in 1969 became a pattern other laboratories reproduced; this paper is the first open description of it with a measured reach, load and speed that could be read. The line runs on to real-time manipulator control in 1985 and to the industrial PUMA, which the atlas does not hold.
The manipulator was meant for a Mars-rover breadboard: pick irregular objects off the surface, hold them up for inspection and place them on the vehicle while avoiding obstacles, with a person intervening only when something goes wrong; the breadboard had a vehicle with stereo cameras, a laser rangefinder and two computers. Power comes from six permanent-magnet DC torque motors geared directly to each link, with rack and pinion on the linear joint and spur gearing on the outer rotary joint; each joint has a brake; position and rate feedback are analogue. What the record does not claim: the Stanford memo AIM-92, Design of a Computer Controlled Manipulator, of June 1969 could not be read (DTIC was under maintenance during this pass, and Stanford's 1969 report archive does not hold it), so the 1969 date of the original arm stands here on bibliographic citations only and is not a record; for the PUMA of 1978 no primary source with a date and a measured result was found, and there is no record of it. The sources do not name the month of the conference.