Bicriteria robotic cell scheduling

Abstract

This paper considers the scheduling problems arising in two-and three-machine manufacturing cells configured in a flowshop which repeatedly produces one type of product and where transportation of the parts between the machines is performed by a robot. The cycle time of the cell is affected by the robot move sequence as well as the processing times of the parts on the machines. For highly flexible CNC machines, the processing times can be changed by altering the machining conditions at the expense of increasing the manufacturing cost. As a result, we try to find the robot move sequence as well as the processing times of the parts on each machine that not only minimize the cycle time but, for the first time in robotic cell scheduling literature, also minimize the manufacturing cost. For each 1-unit cycle in two-and three-machine cells, we determine the efficient set of processing time vectors such that no other processing time vector gives both a smaller cycle time and a smaller cost value. We also compare these cycles with each other to determine the sufficient conditions under which each of the cycles dominates the rest. Finally, we show how different assumptions on cost structures affect the results.

Automated robotic assembly line design with unavailability periods and tool changes

“…Our study is the first one to consider unavailability periods and tool changes in the assembly lines, and to eliminate the tool change related line stoppages. For future research, flexibility can be inserted to the scope of our study by considering controllable processing times instead of using deterministic processing times for the assembly line operations as discussed in Gultekin et al (2008). A challenging future research problem is to consider stochastic task times and/or machine failure and repair models.…”

Design of a Fully Automated Robotic Spot-Welding Line

“…Our study is the first one to consider unavailability periods and tool changes in the assembly lines, and to eliminate the tool change related line stoppages. For future research, flexibility can be inserted to the scope of our study by considering controllable processing times instead of using deterministic processing times for the assembly line operations as discussed in Gultekin et al (2008).…”

Resolution of deadlocks in a robotic cell scheduling problem with post-process inspection system: Avoidance and recovery scenarios

“…One stream is dedicated to bicriteria robotic cells without an inspection process. Following that, [13] looked into the throughput rate as well as machine operating costs, and then determined the set of nondominated solutions for two-machine robotic cells. The novelty of their study was the introduction of each operation time as a nonlinear function of the machine specifications.…”