Scheinman was awarded a research assistantship at the
Stanford Artificial Intelligence Laboratory, working for Bernard Roth on building hands and arms for computers. The lab had an electric prosthetic arm developed circa 1962 by
Rancho Los Amigos Hospital, known as the
Rancho arm, which they had interfaced to a computer. (The arm was originally designed to be controlled with buttons pressed by a user's tongue.) Scheinman was assigned to maintaining the arm but it proved hard to use, with poor accuracy and
inverse kinematics that were difficult to compute. He became involved with new robot designs. One was the Orm arm, (Norwegian for
snake) which he built with Larry Leifer. It consisted of seven stacked plates, with each plate connected to the next by four small pneumatic actuators. Each actuator of which could be inflated or deflated by setting or resetting a bit in a computer word. That arm also proved difficult to control.
Stanford arm In 1969, Scheinman invented the
Stanford arm, The three wrist axes intersect at a point, as prescribed by Pieper's thesis. This allowed the robot to accurately follow arbitrary paths in space under
computer control and widened the potential use of the robot to more sophisticated applications such as assembly and arc welding. The robot also had brakes on each axis, allowing it to be controlled with a time-shared computer. The design became his engineer's degree thesis.
PUMA and Unimation While studying at Stanford, Scheinman was awarded a fellowship sponsored by
George Devol, the inventor of the
Unimate, the first industrial robot. Scheinman traveled with Devol and
Joe Engelberger to
Unimation and several of its customers, observing robot applications, including loading and unloading machines, handling material, and early attempts to do
spot welding. These early robots were hydraulic and programmed by teaching the robot a series of individual points that the robot would repeat each cycle. Some path control could be achieved by defining many intermediated points, but true path following was not possible. The Vicarm and its controller were small enough to be portable and Scheinman brought one to Unimation and set it up on Engelberger's desk, demonstrating the true path control that Unimation's robots could not achieve. He also brought an arm to an early robot trade show at the University of Illinois, but was told it was a toy and could not be in the show, so he set it up on the front steps with an extension cord for power, attracting many researchers who understood its programmability advantage. Engelberger then invited him to bring the robot into his Unimation booth at the show. which offered them for biological lab automation and small part assembly. Scheinman worked for Yaskawa as a consultant for several years, and seven to eight hundred RobotWorld-based systems were sold. ==Personal life==