Speaker: Inna G. Drobouchevitch, University of Ottawa
Time:    Tuesday, September 24, 2:30 p.m.
Place:   room: SITE 5084, SITE building, University of Ottawa
Title:   Scheduling dual gripper robotic cells

Abstract:
The robotic cell - a manufacturing system widely used in industry -
represents a flow shop with a single central robot as the material handling
tool. In the system under consideration, there are two or more bufferless
machines to process the parts, as well as the robot to perform parts
transportation between machines and machine load/unload operations. The
robot arm comprises two grippers, either of which can be in possession of at
most one part. The objective is to determine an ordering of parts at the
input device, as well as a robot move sequence so as to minimize the cycle
time needed to produce a given set of parts. We consider the problem of
scheduling operations for both single part-type and multiple part-type
production in a dual gripper robotic cell. Our main attention is on
so-called one-unit cycles (the cell returns to the same state after the
production of each unit). We provide the notational and modeling framework
to study the problem. Under this framework, we describe the complete family
of one-unit cycles. We investigate the issues of feasibility and
computational complexity of the problem. For the intractable parts
sequencing problems in a two-machine dual-gripper robot cell, we design an
efficient heuristic procedure to tackle these problems and provide the
worst-case analysis of its performance guarantee.