FUZZY-LOGIC AND POSITION SENSING FOR PRECISION ASSEMBLY

The problem of part mating and assembly with close tolerances has been addressed in the past by active or passive compliance and by force/position control. With ambient sensor and transmission noise and with imprecise measurements it is often difficult to attain high precision in manipulator positioning. In this article, a position-sensing wrist using simple strain gauges is described. A fuzzy logic algorithm to ascertain the positional error during an unsuccessful assembly attempt is explained. The results obtained by using this wrist and the fuzzy logic algorithm to reposition a manipulator for precision assembly are presented and discussed. (C) 1995 John Wiley & Sons, Inc.