A model for output evaluation of an intelligent robotic assembly station

Abstract

The evolution of intelligent robots has brought widespread changes in the concept of automatic assembly. An intelligent robot can successfully accomplish assembly in a multiple end product processing and unstructured component part(s) handling environment. This advanced capability of the robot dictates a major change in their basic output characteristics. For example, task service time of an intelligent assembly robot is no longer completely deterministic like that of an ordinary pick-and-place type robot. In this paper, a typical component insertion type assembly task is analyzed to show that the task service time is a random variable consisting of two (2) parts, a deterministic component and a stochastic component. Thus, with the assumption of exponential part input an assembly station served by a single intelligent robot is modeled as an M/G/1 queueing model. A robot availability factor is also introduced into the service time random variable. Closed form expressions for important system performance parameters are obtained under the assumption of three (3) different probability distributions for the stochastic part of the service time random variable.