Application of Dynamic Programming to Optimize Tool Replacement Schedules for Multi-Tool Operations Involving Distributed Tool Lives

1980 ◽  
Vol 102 (3) ◽  
pp. 446-451 ◽  
Author(s):  
H. Bao
Keyword(s):  
Dynamic Programming ◽  
Machining Process ◽  
Large Set ◽  
Moderate Number ◽  
Programming Tool ◽  
Indefinite Number ◽  
Replacement Model ◽  
Tool Replacement ◽  
Tool Set ◽  
Set Up

There have been a number of models developed to provide the optimum tool replacement schedule for a multi-tool set-up. However, most of these models are quite complex and are geared to yield solutions for a very large set-up involving an indefinite number of parts. In this paper a new tool replacement model aimed at a machining process involving a moderate number of tools (2 to 6) and a discrete number of parts (50 to 100) is developed based on the technique of Dynamic Programming. Tool lives in the set-up are assumed to be distributed.

Application of Tree Graph Method for Reducing the Total Time of Tool Changing in Milling and Boring Machine Tools

2013 ◽  
Vol 371 ◽  
pp. 431-435 ◽  
Author(s):  
Claudiu Obreja ◽  
Gheorghe Stan ◽  
Lucian Adrian Mihaila ◽  
Marius Pascu
Keyword(s):  
Machine Tools ◽  
Design Method ◽  
Machining Process ◽  
Cnc Machine Tools ◽  
Tree Graph ◽  
Cnc Machine ◽  
High Productivity ◽  
Automatic Tool Changer ◽  
Automatic Tool ◽  
Set Up

With a view of increasing the productivity on CNC machine tools one of the main solution is to reduce, as much as possible, the auxiliary time consumed with the set-up and replacement of the tools and work pieces engaged in the machining process. Reducing the total time of the tool changing process by the automatic tool changer system can be also achieved through minimizing the number of movements needed for the actual exchange of the tool, from the tool magazine to the machine spindle (the optimization of the tool changing sequences). This paper presents a new design method based on the tree-graph theory. We consider an existing automatic tool changing system, mounted on the milling and boring machining centre, and by applying the new method we obtain all the possible configurations to minimize the tool changing sequence of the automatic tool changer system. By making use of the method proposed we obtain the tool changing sequences with minimum necessary movements needed to exchange the tool. Reconfiguring an existing machine tool provided with an automatic tool changer system by making use of the proposed method leads to obtaining the smallest changing time and thus high productivity.

scholarly journals PROFESSOR ZDZISŁAW ŻYGULSKI JR.: AN OUTSTANDING PERSON, A GREAT PERSONALITY, A MUSEUM PROFESSIONAL, A RESEARCHER ON ANTIQUE WEAPONS, ORIENTAL ART AND EUROPEAN PAINTING (1921–2015)

Muzealnictwo ◽  
2017 ◽  
Vol 58 (1) ◽  
pp. 2-13
Author(s):  
Teresa Grzybkowska
Keyword(s):  
Museum Studies ◽  
The United States ◽  
Leonardo Da Vinci ◽  
Large Set ◽  
New York University ◽  
History Of Art ◽  
The World ◽  
History Of ◽  
Polish Art ◽  
Set Up

Professor Zdzisław Żygulski Jr. (1921–2015) was one of the most prominent Polish art historians of the second half of the 20th century. He treated the history of art as a broadly understood science of mankind and his artistic achievements. His name was recognised in global research on antique weapons, and among experts on Rembrandt and Leonardo da Vinci. He studied museums and Oriental art. He wrote 35 books, about 200 articles, and numerous essays on art; he wrote for the daily press about his artistic journeys through Europe, Japan and the United States. He illustrated his publications with his own photographs, and had a large set of slides. Żygulski created many exhibitions both at home and abroad presenting Polish art in which armour and oriental elements played an important role. He spent his youth in Lvov, and was expatriated to Cracow in 1945 together with his wife, the pottery artist and painter Eva Voelpel. He studied English philology and history of art at the Jagiellonian University (UJ), and was a student under Adam Bochnak and Vojeslav Molè. He was linked to the Czartoryski Museum in Cracow for his whole life; he worked there from 1949 until 2010, for the great majority of time as curator of the Arms and Armour Section. He devoted his whole life to the world of this museum, and wrote about its history and collections. Together with Prof. Zbigniew Bocheński, he set up the Association of Lovers of Old Armour and Flags, over which he presided from 1972 to 1998. He set up the Polish school of the study of militaria. He was a renowned and charismatic member of the circle of international researchers and lovers of militaria. He wrote the key texts in this field: Broń w dawnej Polsce na tle uzbrojenia Europy i Bliskiego Wschodu [Weapons in old Poland compared to armaments in Europe and the Near East], Stara broń w polskich zbiorach [Old weapons in Polish armouries], Polski mundur wojskowy [Polish military uniforms] (together with H. Wielecki). He was an outstanding researcher on Oriental art to which he dedicated several books: Sztuka turecka [Turkish art], Sztuka perska [Persian art], Sztuka mauretańska i jej echa w Polsce [Moorish art and its echoes in Poland]. Prof. Zdzisław Żygulski Jr. was a prominent educator who enjoyed great respect. He taught costume design and the history of art and interiors at the Academy of Fine Arts in Cracow, as well as Mediterranean culture at the Mediterranean Studies Department and at the Postgraduate Museum Studies at the UJ. His lectures attracted crowds of students, for whose needs he wrote a book Muzea na świecie. Wstęp do muzealnictwa [Museums in the world. Introduction to museum studies]. He also lectured at the Florence Academy of Art and at the New York University. He was active in numerous Polish scientific organisations such as PAU, PAN and SHS, and in international associations such as ICOMAM and ICOM. He represented Polish art history at general ICOM congresses many times. He was also active on diverse museum councils all over Poland.

The Simulation and Experimental Analysis of Non-Abrasive Cryogenic Polishing on Metal Cylindrical Surfaces

2012 ◽  
Vol 217-219 ◽  
pp. 1946-1949
Author(s):  
Shou Ping Qu ◽  
Tian Zhu Liang
Keyword(s):  
Physical Model ◽  
Dynamic Simulation ◽  
Experimental Analysis ◽  
Tool Material ◽  
Machining Process ◽  
Metal Material ◽  
Set Up

In the paper, the new machining process which was named non-abrasive cryogenic polishing will be introduced. The model of non-abrasive cryogenic polishing was set up. The dynamic simulation was analyzed by using Recurdyn. And the physical model was accomplished. By analyzing mass experiments, the ice tool material, metal material, rotate speed, polishing time and other parameters were found.

scholarly journals Landscape Quality Valuation for its Preservation and Treasuring

2014 ◽  
Vol 11 ◽  
pp. 625-633 ◽  
Author(s):  
Domenico Enrico Massimo ◽  
Mariangela Musolino ◽  
Antonino Barbalace ◽  
Cinzia Fragomeni
Keyword(s):  
Analysis Tool ◽  
Quality Of Life Research ◽  
Team Research ◽  
Gis Tools ◽  
Landscape Integrity ◽  
New Construction ◽  
Tool Set ◽  
Set Up ◽  
Landscape Units

Pollution, environmental disruption, oversized urban development and infrastructure new construction jeopardize landscape integrity and peoples quality of life. Research deals with the landscape protection and enhancement providing governments and decision makers with a comprehensive Decision Support System to assess the quality of natural and cultural heritage and address planning measures and policy actions for landscape treasuring. Research set-up a sound methodology relying upon GIS tools, to spatially detect and define landscape units along with their endowment such as natural, ecological, historic, cultural, and urban resources then valuated with a GIS integrated multi criteria analysis tool set-up by the research team. Research developed a Case Study in the European Mediterranean Basin, validating the whole system and the performance and support of the GIS tools. Results achieved open the possibility to generalize the prototype application at regional, country and federation levels and therefore support the planning implementation for landscape enhancement.

System Design and Kinematics Simulation of Electrochemical Machining Set-Up for Micro-Holes

2007 ◽  
Author(s):  
Jishun Jiang ◽  
Zhiyong Li
Keyword(s):  
Control Method ◽  
Electrochemical Machining ◽  
Machining Process ◽  
Rectilinear Motion ◽  
Micro Machining ◽  
Technical Requirements ◽  
Kinematics Simulation ◽  
Wide Range ◽  
Micro Holes ◽  
Set Up

Electrochemical micro-machining (EMM) appears to be very promising as a future micro-machining technique, since in many areas of applications, it offers many advantages, which include excellent machining precision and control, high machining rate, perfect surface quality and a wide range of materials that can be machined, regardless of their strength and toughness. At present, electrochemical micro-machining has been applied in the production of some metal workpieces, such as micro-holes, micro-slots and complex 3D surfaces. In this paper, A new electrochemical micro-machining set-up for machining metal micro-holes has been developed. Double level mechanical structure has been applied as the main structure style, which has the advantage of excellent structure rigidity, compact framework dimension as well as perfect maneuverability and maintainability. The control system based on PLC control method has also employed to realize different motion styles for rotating axis, such as uniform velocity rectilinear motion, varying velocity rectilinear motion and cycle rectilinear motion and so on. In order to verify the reliability of this EMM set-up, some test works including static measurement, assembling interferences checking and kinematics simulation have been done. The simulation results demonstrate that the developed EMM set-up for manufacturing metal micro-holes is qualified and can satisfy the technical requirements of electrochemical micro-machining process.

The Application of Fuzzy Comprehensive Evaluation to Cutting Sequences' Optimization of Multi-Feature Part

2011 ◽  
Vol 188 ◽  
pp. 662-666
Author(s):  
Zhe Li ◽  
Min Li Zheng ◽  
Jia He ◽  
Jun Jian Ming
Keyword(s):  
Comprehensive Evaluation ◽  
Evaluation Model ◽  
Fuzzy Comprehensive Evaluation ◽  
Machining Process ◽  
Fuzzy Mathematics ◽  
Cutting Sequences ◽  
Comprehensive Evaluation Model ◽  
Science Management ◽  
Cutting Sequence ◽  
Set Up

The fuzzy comprehensive evaluation which is one of the important embranchment of fuzzy mathematics is often used in the field of science management and decision, but less used in the machining process. Based on the fuzzy mathematical theory, we put forward the establishing process of fuzzy comprehensive evaluation model, and then set up the three-grade fuzzy comprehensive evaluation model of cutting sequence. Three cutting sequences of multi-feature bearing chock component have been evaluated, the evaluation results have verified the rationality and trueness of the model. The application and dissemination of the fuzzy comprehensive evaluation will have active significance in the machining process.

Electro-thermal-based finite element simulation and experimental validation of material removal in static gap single-spark die-sinking electro-discharge machining process

2016 ◽  
Vol 231 (1) ◽  
pp. 28-47 ◽  
Author(s):  
Saeed Assarzadeh ◽  
Majid Ghoreishi
Keyword(s):  
Material Removal ◽  
Thermal Flux ◽  
Machining Process ◽  
Work Piece ◽  
Discharge Time ◽  
Materials Properties ◽  
Element Simulation ◽  
Single Discharge ◽  
Plasma Radius ◽  
Set Up

Existing single spark models are subjected to too simplistic assumptions such as uniform or point heat source, constant plasma radius, invariable materials properties and constant surface temperature during discharge making them far from reality. In this study, more realistic assumptions including Gaussian type distribution of spark heat flux, temperature dependent materials properties, latent heat of melting and expanding plasma channel with pulse current and time have been made to establish a comprehensive modeling platform. The ABAQUS FEM software has been used to simulate the mechanism of crater formation due to a single discharge. The non-uniform thermal flux was programmed through the DFLUX subroutine. The simulation results show that the temperature of work piece decreases as the discharge time increases while the volume of melted and evaporated material increases. A specially designed single spark experimental set-up was developed in laboratory to carry out a few single spark tests for verification purposes. The obtained craters morphologies were examined by optical microscopy and scanning profilometer. It has been shown that the present approach outperforms other previously developed thermal models with respect to cavity outline and size possessing the maximum confirmation errors of 18.1% and 14.1% in predicting crater radius and depth, respectively. Parametric analysis reveals that the melting boundary moves onward by increasing discharge current, whereas it moves back prolonging discharge time. Finally, a closer proximity to experimental material removal rates than those predicted by analytical approach has been recognized which confirms its more precise generalization capabilities towards the real state EDM process.

scholarly journals Manufacturing sequences for the Economic Lot Scheduling problem

1981 ◽  
Vol 24 (3) ◽  
pp. 405-431 ◽  
Author(s):  
James M. Fitz-Gerald ◽  
Elizabeth J. Billington
Keyword(s):  
Optimal Schedule ◽  
Complete Information ◽  
Production Cycle ◽  
Large Set ◽  
Scheduling Problem ◽  
Inventory Costs ◽  
Lot Scheduling ◽  
Economic Lot Scheduling Problem ◽  
Economic Lot Scheduling ◽  
Set Up

In the basic Economic Lot Scheduling problem, a production schedule is required to manufacture sequentially a number of products on a single machine, with the schedule chosen to minimize set-up and inventory costs. The products suffer continuous demand, and no shortfall is allowed. A recent approach involves repetitions of a production cycle (such as ABCBC for three products A, B and C, with manufacturing times chosen to prevent shortage occurring); an exhaustive search is performed over a large set of possible cycles to discover the optimal schedule.This paper discusses the question “How many such sycles need to be examined?”, Since the answer is very relevant to practical application of the method. The case of three products is considered. Complete information is obtained for cycles up to length 12 (that is, 12 production switch overs), and partial results for longer ones. An estimate, apparently reasonable, is obtained for cycles of any length. The major trend to emerge is that surprisingly few cycles are involved.

Error Compensation of a NC Machining System Based on a Dynamic Feedback Neural Network

2011 ◽  
Vol 52-54 ◽  
pp. 1890-1894 ◽  
Author(s):  
Huang Lin Zeng ◽  
Yong Sun ◽  
Xiao Hong Ren ◽  
Li Xin Liu
Keyword(s):  
Neural Network ◽  
Error Compensation ◽  
Nc Machining ◽  
Machining Process ◽  
Dynamic Feedback ◽  
Machining System ◽  
Nc Machine ◽  
Feedback Neural Network ◽  
Set Up ◽  
Errors Analysis

Machining error of a NC machining system is a kind of comprehensive error in dynamically machining process; especially it is of errors with non-linear characteristics. In this paper, we will set up a kind of model of comprehensive errors analysis for a NC machining system and present an error compensation for high-precision a NC machining system by a dynamic feedback neural network embedded in a NC machine tool. The results obtained shows that this approach can effectively improve compensation precision and real time of error compensation on machine tools.

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