Performance management of manufacturing system networks

Performance management of communication networks is critical for speed, reliability, and flexibility of information exchange between different components, subsystems, and sectors (e.g., factory, engineering design, and administration) of production process organizations in the environment of computer integrated manufacturing (CIM). Essential to this distributed total manufacturing system is the integrated communications network over which the information leading to process interactions and plant management and control is exchanged. Such a network must be capable of handling heterogeneous traffic resulting from intermachine communications at the factory floor, CAD drawings, design specifications, and administrative information. The objective is to improve the efficiency in handling various types of messages, e.g., control signals, sensor data, and production orders, by on-line adjustment of the parameters of the network protocol.This paper presents a conceptual design, development, and implementation of a network performance management scheme for CIM applications including flexible manufacturing. The performance management algorithm is formulated using the concepts of: (1) Perturbation analysis of discrete event dynamic systems; (2) stochastic approximation; and (3) learning automata. The proposed concept for performance management can also serve as a general framework to assist design, operation, and management of flexible manufacturing systems.The performance management procedure has been tested via emulation on a network test bed that is based on the manufacturing automation protocol (MAP) which has been widely used for CIM networking. The conceptual design presented in this paper offers a step forward to bridging the gap between management standards and users' demands for efficient network operations since most standards such as ISO and IEEE address only the architecture, services, and interfaces for network management.This work was supported in part by National Science Foundation under Research Grant No. DDM-90-15173.     

An integrated manufacturing network management framework by using mobile agent

The growth in the development of distributed manufacturing systems necessitates increases in efficient technologies in order to facilitate management of the networked resources. Systems such as manufacturing automation protocol (MAP) already exist which were specifically designed for managing networked manufacturing devices. However, MAP has been criticised for being over-complex and expensive for small–medium sized enterprises. The simple network management protocol (SNMP) was designed for managing TCP/IP networks, and we argue that it can also be used for managing networked manufacturing devices. However, SNMP, like MAP, is based upon a client/server architecture, and both have scalability issues. We also investigate the use of mobile agent (MA) technology as a means of managing a domain of manufacturing devices. An integrated network management framework based on MA technology is developed to direct the research into the investigation of aligning network management paradigm to the strategic management decision.     

An off-line robot-programming system with graphics simulation

This paper describes an experimental off-line robot-programming system. This integrated robot-programming system, PC-R, was designed to be independent of the robot as well as to provide off-line graphics simulation of the work situation so that evaluation of the performance could be done rapidly. PC-R comprises several modules, including (a) a robot language compiler; (b) a graphics simulator for modelling the robot and its work environment; (c) a solid-modeller based on the CSG scheme using the technique of ray tracing for solid analysis and visualisation, which interfaces with the simulator and performs interference analysis of the robot programs; and (d) a link to the industrial robot ASEA IRB-6. This ASEA link module is capable of manoeuvring the robot according to the robot programs in real time as well as saving the sequence of robot movements to the robot-controller for later playback execution by the robot.     

A methodology for creating initial state table values for adaptive control of computer integrated cells

The concept of using state tables to define real time control alternatives for an automated manufacturing system has been previously documented; however, the methodology for obtaining values for the control vectors associated with these tables has not been well defined. The procedure presented in this paper utilises several data analysis tools to create, modify, cluster, merge, and recognise control data which is appropriate to a specific control situation. Experiments with a computer-controlled, manufacturing cell, which emphasises material handling, will be utilised throughout to explain the methodology. Experimental results are discussed. Research reported in this paper has been partially supported by NSF Grant CDR 8500022.     

Lot cycle time prediction in a ramping-up semiconductor manufacturing factory with a SOM–FBPN-ensemble approach with multiple buckets and partial normalization

“Ramp-up” is the process of increasing the production rate of a semiconductor manufacturing factory from the first lot to whole volume. Lot cycle time estimation and control during production ramp-up in a semiconductor factory is even more important. However, in addition to the large fluctuation, there are also trends and jumps (sudden increases) in the lot cycle time, which makes it a very challenging task. A SOM–FBPN-ensemble approach with multiple buckets and partial normalization is therefore proposed in this study for lot cycle time prediction in a ramping-up semiconductor manufacturing factory, which was seldom investigated in the past studies. The proposed methodology is composed of two parts. In the first part, the multiple-bucket approach is applied to consider the ramp-up plan of the semiconductor manufacturing factory. Subsequently, the SOM–FBPN-ensemble approach is applied to predict the cycle time of every lot in the ramping-up semiconductor manufacturing factory. The buckets obtained in the first part become additional inputs to the SOM–FBPN, and every parameter is normalized into a range narrower than [0, 1] to reflect the difference between the future and the past. To evaluate the effectiveness of the proposed methodology, a production simulation model was employed in this study. According to experimental results, the prediction accuracy of the proposed methodology was significantly better than those of many existing approaches.     

Implementing lean manufacturing with cellular layout: a case study

Lean manufacturing is an applied methodology of scientific, objective techniques that cause work tasks in a process to be performed with a minimum of non-value adding activities resulting in greatly reduced wait time, queue time, move time, administrative time, and other delays. In a cellular manufacturing system (CMS), machines are grouped into several cells, where each cell is dedicated to a particular part family and the objective is to maximize cell independence. CMS helps in reducing the material handling, work-in-process, setup time, and manufacturing lead time and improve productivity, operation control, etc. The facility layout used during lean implementation can be either be a line layout or in the form of cells. After grouping parts in to various part families, machine cells can be formed to produce those parts well inside the cells. As some of the lean manufacturing concepts are different from that of cellular manufacturing, e.g., establishment of Takt time, Takt-based resource balancing, etc., some new cell design methodology is required to be explored that is compatible with lean manufacturing. The rate at which work progresses through the factory is called flow rate or Takt. In the present work, a design methodology for cellular layout is proposed for implementing lean concepts and is exemplified in a manufacturing industry dealing with ammunition components for defense applications. Based on Takt time for various parts, the production flow among cells was optimized thus minimizing several non-value added activities/times such as bottlenecking time, waiting time, material handling time, etc. This case study can be useful in developing a more generic approach to design cellular layouts in lean environment.     

ICOSS: a two-layer object-based intelligent cell control architecture

This paper reviews past cell control approaches, and addresses a cell control architecture called ICOSS (Intelligent Cell Objects/Intelligent Supporting Shell) that is applicable to an automated manufacturing factory. The ICOSS architecture consists of two layers: the inner layer that we call the intelligent cell objects (ICO), and the outer layer that we call the intelligent supporting shell (ISS). The ICO contains cell control knowledge that can perform generic cell control functions such as scheduling, dispatching and monitoring. The ISS, on the other hand, contains cell databases that represent the specific cell environment. The two layer approach allows more efficiency in developing and implementing intelligent cell control by considering generic cell control knowledge and cell-specific databases separately. The cell control knowledge in both layers are organized using the object hierarchy. The object classes and generic methods (or procedures) defined in each object class are detailed in the paper. In addition, the objects in the ICO can be modified or added by transmitting them through an established computer network rather than being loaded at individual manufacturing cell control computers. The effectiveness of using the ICOSS two-layer architecture will be greater when it is used to update a large number of manufacturing cell controllers in an automated factory.     

Distributed control system utilizing a MAP-based LAN

We developed the ADMAP ADvanced MAP) system as a local area network for our Distributed Instrumentaion Control System (DCS) with a broadcast communications function. ADMAP is an open system based on the Manufacturing Automation Protocol (MAP), which is advancing as an international standard, but also providing real-time performance, which is weak in MAP.

The new MAP-based LAN can be used not only for electrical and computer control. This paper describes the new MAP-based LAN and discusses distributed control systems using this LAN to integrate instrumentation, electrical, and computer controls.     

Assurance of system service level robustness in complex supply chain networks

Despite studies that consider service level rates of individual factories in a supply chain system, the interactions between connected factories and the impact of these interactions on the overall supply chain service level rate have been rarely studied. Moreover, due to uncertainties induced by various sources such as transportation delay and manufacturing processes variability, ensuring the robustness of system service level rate while considering these uncertainties in individual factories is a highly complex task. This paper studies uncertainty effect introduced by factory service level rates on the robustness of overall supply chain network performance, and presents a novel robust design optimization methodology to derive designs of factory service level rates in order to satisfy the service level rate requirement of the system and ensure its robustness. A case study with a multi-level multiple factories supply chain network is used to demonstrate the efficacy of the proposed methodology.     

Distributed manufacturing control of printed circuit boards using map

This paper presents a distributed printed-circuit-board (PCB) manufacturing control system using UNIX computers connected to a MAP local-area network. The requirements and methodology for data distribution and control are illustrated in the context of the PCB production environment, and the implementation issues of tool-operator communication, error-recovery techniques and shopfloor real-time data feedback are discussed. The interfacing of the system with a production scheduler and a CAD manufacturing workstation is also investigated.     

Sequencing of parts and robot moves in a robotic cell

In this paper, we deal with the problem of sequencing parts and robot moves in a robotic cell where the robot is used to feed machines in the cell. The robotic cell, which produces a set of parts of the same or different types, is a flow-line manufacturing system. Our objective is to maximize the long-run average throughput of the system subject to the constraint that the parts are to be produced in proportion of their demand. The cycle time formulas are developed and analyzed for this purpose for cells producing a single part type using two or three machines. A state space approach is used to address the problem. Both necessary and sufficient conditions are obtained for various cycles to be optimal. Finally, in the case of many part types, the problem of scheduling parts for a specific sequence of robot moves in a two machine cell is formulated as a solvable case of the traveling salesman problem.     

Robot system integration into a flexible manufacturing cell

Industrial robots have proved to be a key technology for promoting flexible automation in manufacturing. However, integrating robots into a flexible manufacturing cell (FMC) is still facing a few obstacles. In this paper a research project on the development of a robot and its integration into an FMC is presented. The main research areas of the project were the development of the robot control, the mechanical system, the establishment of an off-line and online programming system, and the links between the cell modules.     

Structural modeling of industrial wireless sensor and actuator networks for reconfigurable mechatronic systems

Recently, the globalization of manufacturing industry systems has led to increase the competition in order to response to today’s demanding market especially in medium-size companies. The global competition requires the manufacturing systems to be flexible and reconfigurable specifically in the shop floor level where mechatronic devices reside. In this paper, a novel methodology for the development and structural modeling of industrial wireless sensors and actuators is presented in order to provide flexibility and reconfigurability to the mechatronic devices. The proposed methodology is based on the implementation of the IEC 61499 standard for the distributed control of mechatronic systems. The methodology also addresses the existing problems of this standard for capturing the system requirements in the development process. For this reason, the Unified Modeling Language is used in order to overcome this problem. A case study is presented in order to demonstrate the operational aspects of the proposed methodology.     

第七讲:工业互联网软件定义工控网络架构在大型装备行业中的应用与部署

随着软件定义网络(SDN)的快速发展,其在工业领域也逐渐成为一种新的网络构建模式用以取代传统的工业生产网络.本文探讨了利用软件定义工业网络等技术,实现制造单元边缘侧的数据快速采集、分析与传递,打通设备层与生产制造以及研发端的数字链路,建设工厂内网络化集成,以实现大型制造企业的生产车间在多项目管理、知识驱动下的快速设计以...     

Performance management of integrated manufacturing system networks

Performance management of communication networks is critical for speed, reliability, and flexibility of information exchange between different components, subsystems, and sectors (e.g., factory, engineering design, and administration) of production process organizations in the environment of Computer Integrated Manufacturing (CIM). The objective is to improve the efficiency in handling various types of messages, e.g., control signals, sensor data and production orders, by on-line adjustment of the parameters of the network protocol. This paper presents conceptual design, development, and implementation of a performance management procedure for CIM applications. The performance management algorithm is formulated using the concepts of: (i) perturbation analysis of discrete event dynamic systems; (ii) stochastic approximation; and (iii) learning automata. The performance management procedure has been tested via emulation on a network testbed that is based on the Manufacturing Automation Protocol (MAP). The conceptual design presented in this paper offers a step forward to bridging the gap between management standards and users' demands for efficient network operations since most standards such as ISO and IEEE address only the architecture, services, and interfaces for network management. The proposed concept for performance management can also be used as a general framework to assist design, operation, and management of flexible manufacturing systems.     

Production engineering-oriented virtual factory: a planning cell-based approach to manufacturing systems design

In the traditional process of designing a manufacturing system, a sequential approach treats each of the design steps individually, without considering the requirements of concurrent design activities. The lack of systematic and concurrent consideration of the interactive impact of design decisions leads to repeated and excessive changes in the design and process. To resolve this problem, this research develops a production engineering-oriented virtual factory – a planning cell-based manufacturing systems design approach. The manufacturing systems design process based on a planning cell is reengineered according to the concept of concurrent engineering. The process modeling of a production engineering-oriented virtual factory is proposed at generic and particular levels. An illustrative example of an engine assembly plant demonstrates the effectiveness of the new approach.     

Production engineering-oriented virtual factory: a planning cell-based approach to manufacturing systems design

In the traditional process of designing a manufacturing system, a sequential approach treats each of the design steps individually, without considering the requirements of concurrent design activities. The lack of systematic and concurrent consideration of the interactive impact of design decisions leads to repeated and excessive changes in the design and process. To resolve this problem, this research develops a production engineering-oriented virtual factory — a planning cell-based manufacturing systems design approach. The manufacturing systems design process based on a planning cell is reengineered according to the concept of concurrent engineering. The process modeling of a production engineering-oriented virtual factory is proposed at generic and particular levels. An illustrative example of an engine assembly plant demonstrates the effectiveness of the new approach.     

Approach to the production environment design task within factory coordination

In a discrete parts batch manufacturing environment, there are different data flows concerning the design of products and manufacturing facilities, customer orders, purchase of materials, production control and delivery of orders. Traditionally, because of the functional allocation of tasks within an organization, there is little integration of information between the production control task and the design of manufacturing facilities. One of the objectives of the design of manufacturing facilities tasks is to efficiently organize a production environment to manufacture a range of products. With a greater relationship between these two tasks, we feel that the complexity of the production control task is reduced. This reduction in complexity arises from a reduction in the range of possible problems that can occur and an increase in the predictability of events through more effective organization of a production environment. Factory coordination is part of an approach to shopfloor control which recognizes this principle by establishing a relationship between the design of a production environment and the control of product flow throughout a factory. This relationship is established through a modular architecture for factory coordination. The production environment design element of the architecture for factory coordination is concentrated on. Using a methodology for describing systems, known as SADT, three main tasks associated with this approach are described; process planning, maintenance of a cellular layout, and manufacturing systems analysis.     

Design of a novel robotic arm with non-backlash driving for friction stir welding process

Application of industrial robots in the field of manufacturing has increased over the years due to their advantages of large workspace, good flexibility and low cost. Industrial robots are trying to replace machine tools for heavy load manufacturing, for instance, friction stir welding (FSW). However, the stiffness of industrial robots is weak which affects the manufacturing precision seriously as well as driving backlash. This paper presents a novel robotic arm with non-backlash that used for FSW process. First, the structure of the robot and how to eliminate the backlash of the robot are introduced. Secondly, a semi-analytical method based on strain energy and the equivalent stiffness of bars obtained by finite element analysis (FEA) is proposed for calculating the overall stiffness of the robot, and the effectiveness of the method is verified through the integrated FEA results. Finally, a FANUC S900iB/400 robot that used for FSW is selected as a representative of industrial robots to be compared, the stiffness of the robot presented in this paper is better than the FANUC robot, which is beneficial to improve the welding quality.