Download or read book Scheduling in Dual Gripper Robotic Cells for Productivity Gains written by Suresh Sethi and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In many applications, robotic cells are used in repetitive production of identical parts. A robotic cell contains two or more robot-served machines. The robot can have single or dual gripper. The cycle time is the time to produce a part in the cell. We consider single part-type problems. Since all parts produced are identical, it is sufficient to determine the sequence of moves performed by the robot. The processing constraints define the cell to be a flowshop. The objective is the minimization of the steadystate cycle time to produce a part, or equivalently the maximization of the throughput rate. The purpose of this paper is to study the problem of scheduling robot moves in dual gripper robot cells functioning in a bufferless environment. We develop an analytical framework for studying dual gripper robotic cells and examine the cycle time advantage (or productivity advantage) of using a dual gripper rather than a single gripper robot. It is shown that an m-machine dual gripper robot cell can have at most double the productivity of its single gripper counterpart. We also propose a practical heuristic algorithm to compare productivity for given cell data. Computational testing of the algorithm on realistic problem instances is also described.
Download or read book Scheduling Dual Gripper Robotic Cell written by Inna Drobouchevitch and published by . This book was released on 2015 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: We consider the scheduling problem of cyclic production in a bufferless dual-gripper robot cell processing a family of identical parts. The objective is to find an optimal sequence of robot moves so as to maximize the long-run average throughput rate of the cell. While there has been a considerable amount of research dealing with single-gripper robot cells, there are only a few papers devoted to scheduling in dual-gripper robotic cells. From the practical point of view, the use of a dual gripper offers the attractive prospect of an increase in the cell productivity. At the same time, the increase in the combinatorial possibilities associated with a dual-gripper robot severely complicates its theoretical analysis. The purpose of this paper is to extend the existing conceptual framework to the dual-gripper situation, and to provide some insight into the problem. We provide a notational and modelling framework for cyclic production in a dual-gripper robotic cell. Focusing on the so-called active cycles, we discuss the issues of feasibility and explore the combinatorial aspects of the problem. The main attention is on 1-unit cycles, i.e., those that restore the cell to the same initial state after the production of each unit. For an m-machine robotic cell served by a dual-gripper robot, we describe a complete family of 1-unit cycles, and derive an analytical formula to estimate their total number for a given m. In the case when the gripper switching time is sufficiently small, we identify an optimal 1-unit cycle. This special case is of particular interest as it reflects the most frequently encountered situation in real-life robotic systems. Finally, we establish the connection between a dual-gripper cell and a single-gripper cell with machine output buffers of one-unit capacity and compare the cell productivity for these two models.
Download or read book Scheduling Multiple Parts in a Robotic Cell Served by a Dual Gripper Robot written by Chelliah Sriskandarajah and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A robotic cell - manufacturing system widely used in industry - contains two or more robot-served machines, repetitively producing a number of part types. In this paper, we consider scheduling of operations in a bufferless dual-gripper robotic cell processing multiple part types. The processing constraints specify the cell to be a flowshop. The objective is to determine the robot move sequence and the sequence in which parts are to be processed so as to maximize the long-run average throughput rate for repetitive production of parts. We provide a framework to study the problem, and address the issues of problem complexity and solvability. Focusing on a particular class of robot move sequences, we identify all potentially optimal robot move sequences for the part-sequencing problem in a two-machine dual-gripper robot cell. In the case when the gripper switching time is sufficiently small, we specify the best robot move sequence in the class. We prove the problem of finding an optimal part sequence to be strongly NP-hard, even when the robot move sequence is specified. We provide a heuristic approach to solve the general two-machine problem and evaluate its performance on the set of randomly generated problem instances. We perform computations to estimate the productivity gain of using a dual-gripper robot in place of a single-gripper robot. Finally, we extend our results for the two-machine cell to solve an m-machine problem.
Download or read book Throughput Optimization in Constant Travel Time Dual Gripper Robotic Cells with Parallel Machines written by Neil Geismar and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Constant travel-time robotic cells with a single gripper robot and with one or more machines at each processing stage have been studied in the literature. By contrast, cells with a dual gripper robot, although more productive, have so far received scant attention, perhaps due to their inherent complexity. We consider the problem of scheduling operations in dual gripper robotic cells that produce identical parts. The objective is to find a cyclic sequence of robot moves that minimizes the long-run average time to produce a part or, equivalently, maximizes the throughput. We provide a structural analysis of cells with one or more machines per processing stage to obtain first a lower bound on the throughput, and subsequently, an optimal solution under conditions that are common in practice. We illustrate our analysis on two cells implemented at a semiconductor equipment manufacturer and offer managerial insights for assessing the potential productivity gains from the use of dual gripper robots.
Download or read book Throughput Optimization in Robotic Cells written by Milind W. Dawande and published by Springer Science & Business Media. This book was released on 2007-05-04 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Throughput Optimization In Robotic Cells provides practitioners, researchers, and students with up-to-date algorithmic results on sequencing of robot moves and scheduling of parts in robotic cells. It brings together the structural results developed over the last 25 years for the various realistic models of robotic cells. This book is ideally suited for use in a graduate course or a research seminar on robotic cells.
Download or read book Throughput Optimization in Dual Gripper Interval Robotic Cells written by Milind Dawande and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interval robotic cells with several processing stages (chambers) have been increasingly used for diverse wafer fabrication processes in semi-conductor manufacturing. Processes such as low-pressure chemical vapor deposition, etching, cleaning and chemical-mechanical planarization, require strict time control for each processing stage. A wafer treated in a processing chamber must leave that chamber within a specified time limit; otherwise the wafer is exposed to residual gases and heat, resulting in quality problems. Interval robotic cells are also widely used in the manufacture of printed circuit boards. The problem of scheduling operations in dual-gripper interval robotic cells that produce identical wafers (or parts) is considered in this paper. The objective is to find a 1-unit cyclic sequence of robot moves that minimizes the long-run average time to produce a part or, equivalently, maximizes the throughput. Initially two extreme cases are considered, namely no-wait cells and free-pickup cells; for no-wait cells (resp., free-pickup cells), an optimal (resp., asymptotically optimal) solution is obtained in polynomial time. It is then proved that the problem is strongly NP-hard for a general interval cell. Finally, results of an extensive computational study aimed at analyzing the improvement in throughput realized by using a dual-gripper robot instead of a single-gripper robot are presented. It is shown that employing a dual-gripper robot can lead to a significant gain in productivity. Operations managers can compare the resulting increase in revenue with the additional costs of acquiring and maintaining a dual-gripper robot to determine the circumstances under which such an investment is appropriate.
Download or read book Approximations to Optimal K Unit Cycles for Single Gripper and Dual Gripper Robotic Cells written by Neil Geismar and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We consider the problem of scheduling operations in bufferless robotic cells that produce identical parts using either single-gripper or dual-gripper robots. The objective is to find a cyclic sequence of robot moves that minimizes the long-run average time to produce a part or, equivalently, maximizes the throughput. Obtaining an efficient algorithm for an optimum k-unit cyclic solution (k ≥ 1) has been a longstanding open problem. For both single-gripper and dual-gripper cells, the approximation algorithms in this paper provide the bestknown performance guarantees (obtainable in polynomial time) for an optimal cyclic solution. We provide two algorithms that have a running time linear in the number of machines: for single-gripper cells (respectively, dual-gripper cells), the performance guarantee is 9/7 (respectively, 3/2). The domain considered is free-pickup cells with constant intermachine travel time. Our structural analysis is an important step towardr esolving the complexity status of finding an optimal cyclic solution in either a single-gripper or a dual-gripper cell. We also identify optimal cyclic solutions for a variety of special cases. Our analysis provides production managers valuable insights into the schedules that maximize productivity for both single-gripper and dual-gripper cells for any combination of processing requirements andphysical parameters.
Download or read book Contemporary Issues in Systems Science and Engineering written by MengChu Zhou and published by John Wiley & Sons. This book was released on 2015-03-30 with total page 890 pages. Available in PDF, EPUB and Kindle. Book excerpt: Various systems science and engineering disciplines are covered and challenging new research issues in these disciplines are revealed. They will be extremely valuable for the readers to search for some new research directions and problems. Chapters are contributed by world-renowned systems engineers Chapters include discussions and conclusions Readers can grasp each event holistically without having professional expertise in the field
Download or read book Approximations to Optimal Sequences in Single Gripper and Dual Gripper Robotic Cells with Circular Layouts written by Neil Geismar and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This article considers the problems of scheduling operations in single-gripper and dual-gripper bufferless robotic cells in which the arrangement of machines is circular. The cells are designed to produce identical parts under the free-pickup criterion with additive intermachine travel time. The objective is to find a cyclic sequence of robotmoves that minimizes the long-run average time required to produce a part or, equivalently, that maximizes the throughput. Obtaining an efficient algorithm for an approximation to an optimal k-unit cyclic solution (over all k≥1) is the focus of this article. The proposed algorithms introduce a new class of schedules, which are refered to as epi-cyclic cycles. A polynomial algorithm with a 5/3-approximation to an optimal k-unit cycle over all cells is developed. The performed structural analysis for dual-gripper cells leads to a polynomial-time algorithm that provides at worst a 3/2-approximation for the practically relevant case in which the dual-gripper switch time is less than twice the intermachine robot movement time. A computational study demonstrates that the algorithm performs much better on average than this worst-case bound suggests. The performed theoretical studies are a stepping stone for researching the complexity status of the corresponding domain. They also provide theoretical as well as practical insights that are useful in maximizing productivity of any cell configuration with either type of robot.
Download or read book Productivity Improvement from Using Machine Buffers in Dual Gripper Cluster Tools written by Neil Geismar and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cluster tools (also referred to as robotic cells) are extensively used in semiconductor wafer fabrication. We consider the problem of scheduling operations in an m-machine cluster tool that produces identical parts (wafers). Each machine is equipped with a unit-capacity input buffer and a unit-capacity output buffer. The machines and buffers are served by a dual-gripper robot. Each wafer is processed on each of the machines, and the objective is to find a cyclic sequence of robot moves that minimizes the long-run average time to produce a part or, equivalently, maximizes the throughput. We first obtain a tight upper bound on the optimal throughput and then use this bound to obtain an asymptotically optimal sequence under conditions that are common in practice. Next, we quantify the improvement in productivity that can be realized from the use of unit-capacity input and output buffers at the machines. Finally, we illustrate our analysis on cluster tools with realistic parameters, based on our work with a Dallas-based semiconductor equipment manufacturer.
Download or read book Scheduling Robotic Cells Served by a Dual Arm Robot written by Neil Geismar and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This article assesses the benefits of implementing a dual-arm robot in a flow shop manufacturing cell. Such a robot has the ability to tend (unload or load) to two adjacent machines simultaneously. This significantly changes the analysis required to find sequences of robot actions that maximize a cell's throughput. For cells processing identical parts, optimal sequences are identified for two- and three-machine cells and also structural results are derived for cells with an arbitrary number of machines. Cells processing different part-types are fully analyzed for the case of two-machine cells. For each case the productivity of single-arm and dual-arm robotic cells is compared.
Download or read book Scheduling in Two machine Robotic Cell written by Radha Penekelapati and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two important trends in developing innovative and efficient approaches for improving plant productivity are cellular manufacturing and robotics. The proliferation of robot technology is an outcome of increasing industrial automation especially in engineering and electronics. Robots offer substantial gains in manufacturing productivity, particularly when integrated into an automated system. Robotic cells involve the use of robots to feed machines in manufacturing cells. The factors affecting the performance of such systems include sequencing robot moves, sequencing parts, buffering, and cell design. This thesis addresses the problem of sequencing robot moves in a two machine manufacturing cell in the presence of a buffer. We develop cycle time formulae using a state space approach. We adopt analytical methods for determining the optimal cycle time of a two-machine robotic cell with a single buffer producing identical parts. We also evaluate the effectiveness of buffering in reducing the cycle time. We extend our research to the robotic cell producing multiple part types. We consider the production of a quantity known as minimal part set (MPS) for multiple part types, to be compatible with the recent trend toward just-in-time manufacturing. Our objective is to identify optimal robot move sequences for a pre-determined arrangement of parts in a minimal part set. We accomplish our goal by developing a branch-and-bound algorithm. We also provide a comparative analysis for scenarios with and without a buffer to establish the usefulness of a buffer.
Download or read book Stochastic Processes Optimization and Control Theory Applications in Financial Engineering Queueing Networks and Manufacturing Systems written by Houmin Yan and published by Springer Science & Business Media. This book was released on 2006-09-10 with total page 397 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited volume contains 16 research articles. It presents recent and pressing issues in stochastic processes, control theory, differential games, optimization, and their applications in finance, manufacturing, queueing networks, and climate control. One of the salient features is that the book is highly multi-disciplinary. The book is dedicated to Professor Suresh Sethi on the occasion of his 60th birthday, in view of his distinguished career.
Download or read book Sequencing and Scheduling in Robotic Cells written by Milind Dawande and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A great deal of work has been done to analyze the problem of robot move sequencing and part scheduling in robotic flowshop cells. We examine the recent developments in this literature. A robotic flowshop cell consists of a number of processing stages served by one or more robots. Each stage has one or more machines that perform that stage's processing. Types of robotic cells are differentiated from one another by certain characteristics, including robot type, robot travel-time, number of robots, types of parts processed, and use of parallel machines within stages. We focus on cyclic production of parts. A cycle is specified by a repeatable sequence of robot moves designed to transfer a set of parts between the machines for their processing. We start by providing a classification scheme for robotic cell scheduling problems that is based on three characteristics: machine environment, processing restrictions, and objective function, and discuss the influence of these characteristics on the methods of analysis employed. In addition to reporting recent results on classical robotic cell scheduling problems, we include results on robotic cells with advanced features such as dual gripper robots, parallel machines, and multiple robots. Next, we examine implementation issues that have been addressed in the practice-oriented literature and detail the optimal policies to use under various combinations of conditions. We conclude by describing some important open problems in the field.
Download or read book Handbook of Research on AI and Knowledge Engineering for Real Time Business Intelligence written by Hiran, Kamal Kant and published by IGI Global. This book was released on 2023-04-04 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: Artificial intelligence (AI) is influencing the future of almost every sector and human being. AI has been the primary driving force behind emerging technologies such as big data, blockchain, robots, and the internet of things (IoT), and it will continue to be a technological innovator for the foreseeable future. New algorithms in AI are changing business processes and deploying AI-based applications in various sectors. The Handbook of Research on AI and Knowledge Engineering for Real-Time Business Intelligence is a comprehensive reference that presents cases and best practices of AI and knowledge engineering applications on business intelligence. Covering topics such as deep learning methods, face recognition, and sentiment analysis, this major reference work is a dynamic resource for business leaders and executives, IT managers, AI scientists, students and educators of higher education, librarians, researchers, and academicians.
Download or read book Modeling Scheduling and Performance Evaluation for Deadlock free Flexible Manufacturing Cells for a Dual Gripper Robot written by Nabil EL Khairi and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INFORMS Conference Program written by Institute for Operations Research and the Management Sciences. National Meeting and published by . This book was released on 2000 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
