Selection of warehouse-transportation vehicles using discrete simulationsMatjaž Šraml
, Tone Lerher
, Grega Ljubej
, 2008, objavljeni znanstveni prispevek na konferenci
Opis: In this paper four different types of warehousingtransportation vehicles (lifttrucks and stacker crane) are analyzed. The complexity of designing warehousing systems in an analytical way is high; therefore the discrete simulation models were performed in order to gain the basic data for different types of warehousing-transportation vehicles. First, the counter balance lift truck is analyzed, which is useful for a lower rack warehouse construction and a lower frequency of operation. Next, the reach truck is analyzed; it enables to achieve higher lifting places, with a relatively high frequency and lift capacity. The narrow aisle lift truck can reach heights up to twelve meters, and is suitable for high frequency demands and lift capacities. Finally, the automated storage and retrieval system is analyzed. The presented models prove to be a very useful and flexible tool for choosing a particular type of warehousing system on the first stage of designing the warehouse process.
Ključne besede: discrete numeric simualtions, transport warehousung unit, warehouse system
Objavljeno: 31.05.2012; Ogledov: 1139; Prenosov: 27
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Automated and intelligent programming of cnc machine toolsAfrim Gjelaj
, 2014, doktorska disertacija
Opis: Nowadays, many scientists focus on increasing the level of automation, respectively flexibility in manufacturing systems. In addition, automated programming of CNC machine tools has reached a high level of machining operations. However, it is still impossible for a machine to manipulate completely in an autonomous way. Special attention in this doctoral thesis is focused on the automated programming of CNC machine tools regarding artificial intelligence. The purpose of automated programming is to improve quality and to fulfil the requirements of manufacturing industry and provide commercial solutions. This thesis also provides a description of artificial intelligence usage in order to solve optimal tool path-length and tool selection, as well as the preparation of planned technology. Firstly, the automated programming of CNC machine tools enjoys great success when applying artificial intelligence in regard to the machining processes. Choices of path length and tool selection are analysed in great detail in order to ascertain the optimal problems of tool path- length and tool selection. However, in order to achieve automated and intelligent CNC programming of machine tools, their flexibilities are of major importance. Automation today tends to improve and implement manufacturing flexibility at a strategic level. This means increasing the degree of flexibility whilst at the same time increasing the degree of automation regarding CNC machine tools. In addition to the above-mentioned investigated problems, the influences of cutting force (Fc), power cutting (Pc), tool life (T) and surface roughness (Ra) as functions of tool path- length are also analysed. Analytical and mathematical models are optimised using a multi-objective genetic algorithm (MOGA). MOGA enables optimisation by employing two or more equations simultaneously. Another problem for the automated and intelligent CNC programming of machine tools focuses on the application of Discrete Systems (DS). The discrete system in our work focuses on analysing cutting force (Fc) in regard to the turning operation.
Ključne besede: inteligent CNC programming, intelligent manufacturing, discrete system, automated programming, multiobjective genetic algorithm MOGA
Objavljeno: 23.01.2015; Ogledov: 1887; Prenosov: 313
Celotno besedilo (1,57 MB)