Overview of basic production system structures.
[vc_row][vc_column width=”2/3″][vc_custom_heading text=”12″ google_fonts=”font_family:Oldenburg%3Aregular|font_style:400%20regular%3A400%3Anormal”][vc_column_text]
Abstract
From the theoretical point of view, the chapter focuses on the unification of views on the living (constantly changing) structure of the construction of flexible production systems, including its cooperating devices. It contains currently defined and designated technical terms in the field of flexible production systems. From the theoretical point of view, the existing structures of the “multiprofessional manufacturing robotic center” are enhanced with new elements, which also contributes to innovation and expansion of their applications. These structural structures served as the basis for building sophisticated modular structures. Modularity is an integrating element directed at highly customizable manufacturing engineering structures. It fully complies with the requirements of manufacturing practice and demanding market, in the framework of fully implemented Industry 4.0 (I4.0) under way.
[/vc_column_text][vc_column_text]
1. Introduction
Modular manufacturing systems, as an integrated part of flexible manufacturing systems, deserve an unmistakable merit in today’s rapidly changing manufacturing environment, characterized by developed competition in the global context and progressive changes in process technologies and in their structure according to market requirements. Such systems necessitate a rapid and factual integration of new technologies and new functions into both system and process relationships.
The Industry 4.0 (I4.0) trends and conditions and requirements require cyber and flexible production-oriented approach, enabling to build the following:
-
A production capacity of production systems that is operatively adaptive to market requirements, i.e., obtaining new, rapidly viable products
-
Fast integration of modern process technologies and new functions into existing production systems and their easy adaptation to dynamically changing batches of individual products
-
Integrated production units with new service capabilities based on robust Industry Internet of Things (IIoT) data streams from individual work units and their accessibility for being processed from anywhere subject to Internet connection
[/vc_column_text][vc_column_text el_id=”test”]
2. Flexible manufacturing systems
Flexible manufacturing systems (FMS) enable flexible production of a product group in a single production system. Using modular principles, flexible manufacturing, which is the fundamental concept of cyber production systems, has recently become one of the major systems of production management. These arrangements are (and there are several of them) theoretically and methodically based on the search for a mathematically modeled component production center relationship that would guarantee different types of parts produced with a small number of pieces in the batch. The modular structure of the production systems enables links between machines, saving production time and space. The operation of the machines is synchronized via data stream, and the material flow is optimized (moving parts between machines is at an optimal distance). FMS utilizes many advantages of other types of production structures ( Table 1 ) [1].
| Type of production | Structure definitions and objectives |
|---|---|
| Production line | The line is designed for the production of a (one) specific product, using the technology of gradual production with given tools and a fixed level of automation. The economic goal of production lines is to produce one particular type of product in large quantities and the required quality cost-effectively |
| Flexible manufacturing system (FMS) | The structure of a production system with fixed hardware and programmable software for affecting changes in the assortment produced according to current orders and changes in production plans with tools for several product types. The economic objective of FMS is to ensure an efficient production of several types of products, which may change over time with the respective changes taking up shorter time on the same production system, while maintaining the requirements for the production’s prescribed scope and quality. |
| Reconfigurable manufacturing system (RMS) | A structure of the manufacturing system that can be created through multiple groupings of basic process configurations of changeable system modules (hardware and software). Reconfiguration allows for the addition, removal, or modification of specific process features, controls, control software, or machine structure to adapt the system’s production capacity to changes in market demand or to the necessary and related technological changes. This system structure guarantees the flexibility of the system for a specific product group, while the system is technically ready for change so that it can be further improved, upgraded, and reconfigured and not merely replaced [2, 3]. The goal of RMS is to provide the functionality and capacity that is needed at any given time. In terms of the system composition, RMS configuration can be reserved or flexible or changeable as needed between these two properties. The RMS goals exceeds the FMS goals in terms of economy, allowing the following:
|
Table 1.
The dynamic development of computers, information science, data processing, control and managing systems, optical systems, drives, and materials, that is taking place in short cycles, significantly affects the growth rate (obsolescence) of the technical level of the systems in question. An efficient manufacturing system can become inefficient in a short time. In addition, the current customer-oriented market, as well as the environmental, energy and material issues, results in accelerated launch of new products. The adaptability of established manufacturing systems to new products may not have sufficient technical availability, and the introduction of new technically available systems may take too long a time from the production availability point of view (machine tools approximately 2 years).
For these reasons, it is necessary to pay constant attention to flexible, modular, and reconfigurable production systems and consequently to improve them systematically and technically and adapt them to the needs of current production processes or to the needs of current engineering production [1, 2].
Generally, the best-selling article (or article with the highest investment value) of production technology are the CNC machine tools. Prof. Marek writes in [3] about the factors influencing the development of machine tools.
Forecasts focused on the position of modular technologies in the twenty-first century confirm their important place in both fully automated production plants (both engineering and nonengineering areas) and in non-production areas (service and maintenance activities).
Thus, the modularity and reconfigurability in terms of where the development is heading have the potential for further development in the future. Design of reliable (universal) modules or of the building nodes with a wider applicability is, and will always be, topical. This desired property can be achieved through experience, selection of suitable elements, and reliable design. In terms of reliability and reconfigurability, two areas need to be focused on:
-
Design of machine tools (machine reconfiguration to another type of workpiece)
-
Production (technology reconfiguration to another type of workpiece)
The concept of flexibility is also related to reconfigurability and structurelability. Flexibility can also be seen from the point of view of design and manufacturing development ( Figure 1 ).
Figure 1.
An unconventional view of the “flexibility” concept.
The possibilities and tools for increasing the performance of production machines in multifunction machinery are associated with the developed ability to fully perform several types of machining, e.g., turning and milling at the same time or milling and grinding, etc. Reducing the number of machine tools for the production of one component, less handling, shortening the lead times, minimizing the recurrence of workpiece clamping, maximizing the concurrence of operations, as well as the development of machine components and machine concepts for maximum machine multifunctionality contribute to:
-
Increased accuracy
-
Increased production capacity
-
Increased economy
-
Reduced negative impacts on the environment
Unification of parts and components is implemented in order to minimize diversity of the components used, while maintaining very good static and dynamic properties of the machines and, at the same time:
-
Increasing reliability
-
Increasing economy
[/vc_column_text][vc_column_text el_id=”test2″]
2.1 New approach to production systems classification
In the area of production systems, a number of terms are used with broader interpretation. This situation is related to approaches to and perspectives on this issue. A proposal for their general unification and effective classification is given in Figure 2 .
Figure 2.
Open proposal for production systems classification.
Various definitions of production systems from different points of view are cited in various literature sources [1]. This has led to the need to harmonize these formulations so that they provide the most precise definitions, taking into account current knowledge in this area:
Flexible production system—afunctional grouping of production facilities linked by material flow and information network, enabling the use of flexible change in production facilities due to the introduction of new products in relatively short time intervals, to produce small quantities efficiently.
Structural production system—flexible set of compatible elements (technological and positioning units, supporting frame, cooling system, etc.) and their mutual links, which can be expanded with new elements to change the system parameters.
Modular system—flexible set of unified modules (module—separately functional unit) in functionally logical (in terms of structure, system, concept, kinematics, etc.) arrangement into higher functional unit (meeting required parameters and working functions).
Reconfigurable system—a modular system with the possibility to change the arrangement of its own modules (in terms of structure, system, concept, kinematics, etc.) in order to create an innovated system with innovated properties.
Self-reconfigurable system—a reconfigurable system capable of independently reconfiguring its own modules (in terms of structure, system, concept, kinematics, etc.) to create an innovated system with innovated features.
Metamorphic system—a closed self-reconfigurable system to create an innovated system with innovated features (def. Inspired by [4]).
Fractal system—an open, self-reconfigurable system consisting of proactively behaving elements—fractals (their structure is recurrent) which pursue a common goal (def. Inspired by [5]).
2.2 Modular production centers
In the category of manufacturing technology, machining centers (MC) are defined as manufacturing machines designated for complex components machining with defined characteristics. According to the number and type of technological operations performed, machining centers are divided into:
-
Multipurpose (multi-operation)—machines with a predominant technological operation (e.g., turning), i.e., they mostly enable one type of technology
-
Multiprofessional (multiprofessional productions center (MPC))—machines on which various technological operations can be performed (e.g., turning, milling, drilling, etc.)
Production centers are conceptually built on the principles of modular systems or as modular single-purpose machines. In terms of design and structure, they are assembled from technological, handling, and auxiliary units (mechanical, electromechanical, hydraulic, pneumatic) integrated through a supporting element (frame) into one functional and structural unit. The highest integration of production centers is based on the automation of technological and handling operations. These are multiprofessional machine tools designed for complex machining of parts on one machine and, if possible, requiring one clamping. To machine a workpiece requiring one clamping, its rotation must be ensured (e.g., in the X-Y plane) and so must be its tilting. The machining centers are equipped with a tool magazine automatically replaced by a mechanical hand. Some tools feature their own drive, which makes drilling off the workpiece axis or its milling possible, especially on lathes. Machining centers represent the basic AVS production machines. They are mainly used in piece and small batch production. Machining centers are characterized by a high concentration of operations. The machining is often carried out with the component clamped only once. They are mostly equipped with tool magazines exchanged automatically as needed. The most common main feature of machining centers is the largest machined part dimension.
[/vc_column_text][/vc_column][vc_column width=”1/3″ el_id=”sidebarx”][vc_column_text][addtoany][/vc_column_text][vc_column_text]Test[/vc_column_text][vc_column_text]Test[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]
2.1 New approach to production systems classification
In the area of production systems, a number of terms are used with broader interpretation. This situation is related to approaches to and perspectives on this issue. A proposal for their general unification and effective classification is given in Figure 2 .
Figure 2.
Open proposal for production systems classification.
Various definitions of production systems from different points of view are cited in various literature sources [1]. This has led to the need to harmonize these formulations so that they provide the most precise definitions, taking into account current knowledge in this area:
Flexible production system—afunctional grouping of production facilities linked by material flow and information network, enabling the use of flexible change in production facilities due to the introduction of new products in relatively short time intervals, to produce small quantities efficiently.
Structural production system—flexible set of compatible elements (technological and positioning units, supporting frame, cooling system, etc.) and their mutual links, which can be expanded with new elements to change the system parameters.
Modular system—flexible set of unified modules (module—separately functional unit) in functionally logical (in terms of structure, system, concept, kinematics, etc.) arrangement into higher functional unit (meeting required parameters and working functions).
Reconfigurable system—a modular system with the possibility to change the arrangement of its own modules (in terms of structure, system, concept, kinematics, etc.) in order to create an innovated system with innovated properties.
Self-reconfigurable system—a reconfigurable system capable of independently reconfiguring its own modules (in terms of structure, system, concept, kinematics, etc.) to create an innovated system with innovated features.
Metamorphic system—a closed self-reconfigurable system to create an innovated system with innovated features (def. Inspired by [4]).
Fractal system—an open, self-reconfigurable system consisting of proactively behaving elements—fractals (their structure is recurrent) which pursue a common goal (def. Inspired by [5]).
2.2 Modular production centers
In the category of manufacturing technology, machining centers (MC) are defined as manufacturing machines designated for complex components machining with defined characteristics. According to the number and type of technological operations performed, machining centers are divided into:
-
Multipurpose (multi-operation)—machines with a predominant technological operation (e.g., turning), i.e., they mostly enable one type of technology
-
Multiprofessional (multiprofessional productions center (MPC))—machines on which various technological operations can be performed (e.g., turning, milling, drilling, etc.)
Production centers are conceptually built on the principles of modular systems or as modular single-purpose machines. In terms of design and structure, they are assembled from technological, handling, and auxiliary units (mechanical, electromechanical, hydraulic, pneumatic) integrated through a supporting element (frame) into one functional and structural unit. The highest integration of production centers is based on the automation of technological and handling operations. These are multiprofessional machine tools designed for complex machining of parts on one machine and, if possible, requiring one clamping. To machine a workpiece requiring one clamping, its rotation must be ensured (e.g., in the X-Y plane) and so must be its tilting. The machining centers are equipped with a tool magazine automatically replaced by a mechanical hand. Some tools feature their own drive, which makes drilling off the workpiece axis or its milling possible, especially on lathes. Machining centers represent the basic AVS production machines. They are mainly used in piece and small batch production. Machining centers are characterized by a high concentration of operations. The machining is often carried out with the component clamped only once. They are mostly equipped with tool magazines exchanged automatically as needed. The most common main feature of machining centers is the largest machined part dimension.
[/vc_column_text][/vc_column][/vc_row]
