lnI J Adv Manuf Technol (1990)5:345-357 9 1990 Springer-Verlag London Limited The International Journal of Advanced Manufacturing Technology OPTIMAL INDUSTRIAL ROBOT- CALIBRATION POLICY S. P. Ladany and D. Ben-Arieh Department of Industrial Engineering and Management, Ben-Gurion University of the Negev, PO Box 653, Beer Sheva, Israel The optimal determimstic calibration poliO' for a robot cyclically performing a single production-integrated activity has been determi~wd anah:tically. The general solution derived has been analysed mu~wrically, and its sensitivi O" to changes in the parameters has been established, The model assumptions and the results have been validated on a/t industrial robot, Keywords: Calibration; Reset; Robotics 1. Introduction Robots integrated into a production process, where they move a workpiece and position it for machining, exhibit changes in their performance. These changes can be diflerentiated as chance wmations and assignable variations. The chance variations cause the production variable of interest to be distributed around a mean, at which the robot is set up. The assignable variations cause a gradual change in the mean value of the variable. This gradual loosening of the set-up is a function of the number of repetitions (cycles) the robot has performed since the last set tip (calibration). Conformity of the manufactured product with the set of specification limits determines the product's grade and its economic value. Thus, even when the robot is properly set up, the chance variations may cause a certain fraction of nonconforming units to be produced. However, as the number of pieces produced by the robot since the last set-up increases, so does the fraction of nonconforming units. Accepted .for publication: I0 April 1990