An Integrated Approach to the Optimal Sequencing of Robot Operations in a Workcell

Abstract

In this paper we develop an integrated approach to optimally sequence robot operation in a workcell. The workcell represents a flowshop containing multiple robots with known inverse kinematic solution that are used to transport jobs among machines. The objeotive is to determine the sequence of robot operations so as to minimize the total time needed to complete all jobs (known as makespan). The integrated approach consists of determining optimal robot task sequences using a branch and bound procedure, and a graphical simulation procedure to display robot motion during the performance of transport operations. The graphical simulation is used to detect interference among robots which is hard to be incorporated in the branch and bound procedure. Infeasible robot sequences are discarded and other solutions from the branch and bound procedure are displayed using the graphical simulation procedure to determine a near optimal and feasible sequence. The integrated approach is implemented on a prototype system.