Energy Efficient Scheduling in Flow-shop and Parallel Machine Robotic Cells

2021-9-10
Aydoğan, Çiya
Robotic cell scheduling studies mostly focus on increasing the throughput of the cell. Therefore, those studies consider cycle time or makespan minimization objectives. However, energy-efficient and environmentally sensitive manufacturing operations become more important and receive attention in recent studies in the literature. In this thesis, we study two robotic cell scheduling problems with machines and a material handling robot. We consider robot energy consumption as an objective to minimize while maximizing the throughput. The problem is to find efficient solutions for these objectives. Two scheduling environments are studied: a two machine flow-shop robotic cell and a two parallel machine robotic cell. In a flow-shop scheduling environment, parts are processed on both machines, but in a parallel machine scheduling environment, parts are processed on one of two machines. In both robotic cells, a robot performs all handling and loading-unloading operations. The robot consumes energy during its moves. We assume that the energy consumption can be formulated as a convex nonlinear function of robot's speed. We try to find the optimal robot move sequence and optimal speed of the robot to minimize energy consumption and makespan (or cycle time). We also make other scheduling decisions such as part sequencing and machine-part assignment. For the flow-shop robotic cell scheduling problem we propose a mathematical model that finds efficient solutions for energy consumption and cycle time objectives. We solve the model using mixed integer second-order conic programming (MISOCP) reformulation. For the parallel machine robotic cell, similarly, we propose a mathematical model and its MISOCP reformulation to find efficient solutions. We also propose alternative neighborhood search algorithms based on Simulated Annealing. For both problems, we test the computational performance of proposed solution approaches and present energy saving achieved by robot speed control strategy.

Suggestions

Energy conscious machine and robot speed decisions in two machine robotic cell scheduling
Güzel, Betül Necibe; Gürel, Sinan; Department of Industrial Engineering (2021-6-15)
Minimizing cycle time has always been a critical objective in manufacturing cells. Recently, energy efficient and environmentally conscious manufacturing practices have received increasing attention from researchers and practitioners. Therefore, in this thesis we consider a 2-machine manufacturing cell with a material handling robot where two conflicting objectives exist: minimization of cycle time and energy consumption. It is a flow type cell where identical parts are first processed on the first machine ...
Object-Oriented Segmentation of Cell Nuclei in Fluorescence Microscopy Images
Koyuncu, Can Fahrettin; Atalay, Rengül; GÜNDÜZ DEMİR, Çiğdem (Wiley, 2018-10-01)
Cell nucleus segmentation remains an open and challenging problem especially to segment nuclei in cell clumps. Splitting a cell clump would be straightforward if the gradients of boundary pixels in-between the nuclei were always higher than the others. However, imperfections may exist: inhomogeneities of pixel intensities in a nucleus may cause to define spurious boundaries whereas insufficient pixel intensity differences at the border of overlapping nuclei may cause to miss some true boundary pixels. In co...
Energy conscious scheduling of a material handling robot in a manufacturing cell
Gürel, Sinan; Akhlaghi, Vahid Eghbal (Elsevier BV, 2019-08-01)
In cyclic scheduling of material handling robots in manufacturing cells, a common approach is to minimize the cycle time objective, which is a measure of the throughput of the cell. In a typical robot move cycle, robot move times constitute a significant portion of the cycle time. During handling operations, robots consume significant amount of energy, which is determined by their speed, load and the distance they travel. In this paper, we propose considering robot speed decisions along with robot move sequ...
Scheduling in two-machine robotic cells with a self-buffered robot
Gündoğdu, Emine; GÜLTEKİN, HAKAN (2016-02-01)
This study considers a production cell consisting of two machines and a material handling robot. The robot has a buffer space that moves with it. Identical parts are to be produced repetitively in this flowshop environment. The problem is to determine the cyclic schedule of the robot moves that maximizes the throughput rate. After developing the necessary framework to analyze such cells, we separately consider the single-, double-, and infinite-capacity buffer cases. For single- and double-capacity cases, c...
Integration of topological measures for eliminating non-specific interactions in protein interaction networks
BAYIR, Murat Ali; GUNEY, Tacettin Dogacan; Can, Tolga (Elsevier BV, 2009-05-28)
High-throughput protein interaction assays aim to provide a comprehensive list of interactions that govern the biological processes in a cell. These large-scale sets of interactions, represented as protein-protein interaction networks, are often analyzed by computational methods for detailed biological interpretation. However, as a result of the tradeoff between speed and accuracy, the interactions reported by high-throughput techniques occasionally include non-specific (i.e., false-positive) interactions. ...
Citation Formats
Ç. Aydoğan, “Energy Efficient Scheduling in Flow-shop and Parallel Machine Robotic Cells,” M.S. - Master of Science, Middle East Technical University, 2021.