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Linear motor drive system for continuous-path closed-loop position control of an object

Patent ·
OSTI ID:863650
A precision numerical controlled servo-positioning system is provided for continuous closed-loop position control of a machine slide or platform driven by a linear-induction motor. The system utilizes filtered velocity feedback to provide system stability required to operate with a system gain of 100 inches/minute/0.001 inch of following error. The filtered velocity feedback signal is derived from the position output signals of a laser interferometer utilized to monitor the movement of the slide. Air-bearing slides mounted to a stable support are utilized to minimize friction and small irregularities in the slideway which would tend to introduce positioning errors. A microprocessor is programmed to read command and feedback information and converts this information into the system following error signal. This error signal is summed with the negative filtered velocity feedback signal at the input of a servo amplifier whose output serves as the drive power signal to the linear motor position control coil.
Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN
DOE Contract Number:
W-7405-ENG-26
Assignee:
United States of America as represented by United States (Washington, DC)
Patent Number(s):
US 4221995
OSTI ID:
863650
Country of Publication:
United States
Language:
English