Reliability enhancement of manufacturing systems through functions

2015 ◽  
Vol 231 (10) ◽  
pp. 1850-1868 ◽  
Author(s):  
MK Loganathan ◽  
OP Gandhi
Keyword(s):  
Manufacturing Systems ◽  
Manufacturing System ◽  
Systems Approach ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
System Structure ◽  
Reliable System ◽  
Graph Theoretic ◽  
Reliability Enhancement ◽  
Graph Theoretic Models

A reliable system means being able to perform its intended functions. Therefore, ensuring performing of its required functions will help to enhance its reliability. For a manufacturing system (e.g. computer numerical control machines), there are a large number of functions, which complicate and make analysis difficult. In this article, a logical and systems approach of graph theory, which is effective to eliminate such difficulties, is employed. The graph theoretic models do consider the system structure explicitly and are applied to model functions at various hierarchical levels of a manufacturing system. These function digraph models are analysed using matrix approach to examine the cause and effect, which helps to evaluate importance of the function and hence provide direction for system reliability enhancement. A step-by-step methodology is presented, which is illustrated by an example of manufacturing system: computer numerical control drilling machine.

Synergistic real-time compensation of tracking and contouring errors for precise parametric curved contour following systems

2017 ◽  
Vol 232 (19) ◽  
pp. 3367-3383 ◽  
Author(s):  
De-Ning Song ◽  
Jian-Wei Ma ◽  
Zhen-Yuan Jia ◽  
Feng-Ze Qin ◽  
Xiao-Xuan Zhao
Keyword(s):  
Real Time ◽  
High Precision ◽  
Tracking Error ◽  
Estimation Algorithm ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
System Structure ◽  
Parametric Curve ◽  
Contouring Error ◽  
Contour Following

The tracking and contouring errors are inevitable in real computer numerical control contour following because of the reasons such as servo delay and dynamics mismatch. In order to improve the motion accuracy, this paper proposes a synergistic real-time compensation method of tracking and contouring errors for precise parametric curve following of the computer numerical control systems. The tracking error for each individual axis is first compensated, by using the feed-drive models with the consideration of model uncertainties, to enhance the tracking performances of all axes. Further, the contouring error is estimated and compensated to improve the contour accuracy directly, where a high-precision contouring-error estimation algorithm, based on spatial circular approximation of the desired contour neighboring the actual motion position, is presented. Considering that the system structure is coupled after compensation, the stability of the coupled system is analyzed for design of the synergistic compensator. Innovative contributions of this study are that not only the contouring-error can be estimated with a high precision in real time, but also the tracking and contouring performances can be simultaneously improved although there exist modeling errors and disturbances. Simulation and experimental tests demonstrate the effectiveness and advantages of the proposed method.

Cyber-Physical Manufacturing Systems

2019 ◽  
Vol 2 (1) ◽  
pp. 427-443 ◽  
Author(s):  
Dawn M. Tilbury
Keyword(s):  
Manufacturing Systems ◽  
Computer Numerical Control ◽  
Cyber Physical Systems ◽  
Numerical Control ◽  
Programmable Logic ◽  
Programmable Logic Controllers ◽  
Physical Systems ◽  
Multiple Levels ◽  
Networking Technologies ◽  
Logic Controllers

Cyber-physical systems, in which computation and networking technologies interact with physical systems, have made great strides into manufacturing systems. From the early days, when electromechanical relays were used to automate conveyors and machines, through the introduction of programmable logic controllers and computer numerical control, computing and networking have become pervasive in manufacturing systems. By increasing the amount of automation at multiple levels within a factory and across the enterprise, cyber-physical manufacturing systems enable higher productivity and higher quality as well as lower costs.

scholarly journals AVANCES EN EL DESARROLLO DE UN SISTEMA DE MANUFACTURA ADITIVA BASADO EN STEP-NC

2018 ◽  
Vol 4 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Efrain Rodriguez ◽  
Renan Bonnard ◽  
Alberto José Alvares
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Reference Model ◽  
Object Oriented Programming ◽  
Numerical Control ◽  
Layer By Layer ◽  
Machining Processes ◽  
Material Deposition ◽  
Nc Program

The new standard of numerical control, known as STEP-NC, is categorized as the future of the advanced manufacturing systems. Greater flexibility and interoperability are some potential benefits offered by STEP-NC to meet the challenges of the new industrial landscape that is envisaged with the advent of Industry 4.0. Meanwhile, STEP-NC object-oriented programming has been partially applied and developed for machining processes (milling, turning...). But with the processes of additive manufacturing has not happened the same and the development is still incipient. This work presents the advances in the development of a new STEP-NC compliant additive manufacturing system, focusing particularly on the development of the information model. The application model activities in the IDEF0 nomenclature and application reference model in EXPRESS are presented. The AM-layer-feature concept has been introduced to define the manufacturing feature of additive processes based on material deposition layer-by-layer. Finally, a STEP-NC program generated from the EXPRESS model is presented, which can be implemented on an additive manufacturing system to validate the proposed model.                                                                                           

Intrusion Detection System for Cyber-Manufacturing System

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Mingtao Wu ◽  
Young B. Moon
Keyword(s):  
Intrusion Detection ◽  
Intrusion Detection System ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Detection System ◽  
Numerical Control ◽  
System Level ◽  
Cnc Milling ◽  
Physical Data ◽  
Physical Components

Cyber-manufacturing system (CMS) offers a blueprint for future manufacturing systems in which physical components are fully integrated with computational processes in a connected environment. Similar concepts and visions have been developed to different extents and under different names—“Industrie 4.0” in Germany, “Monozukuri” in Japan, “Factories of the Future” in the EU, and “Industrial Internet” by GE. However, CMS opens a door for cyber–physical attacks on manufacturing systems. Current computer and information security methods—firewalls and intrusion detection system (IDS), etc.—cannot detect the malicious attacks in CMS with adequate response time and accuracy. Realization of the promising CMS depends on addressing cyber–physical security issues effectively. These attacks can cause physical damages to physical components—machines, equipment, parts, assemblies, products—through over-wearing, breakage, scrap parts or other changes that designers did not intend. This research proposes a conceptual design of a system to detect cyber–physical intrusions in CMS. To accomplish this objective, physical data from the manufacturing process level and production system level are integrated with cyber data from network-based and host-based IDSs. The correlations between the cyber and physical data are analyzed. Machine learning methods are adapted to detect the intrusions. Three-dimensional (3D) printing and computer numerical control (CNC) milling process are used as examples of manufacturing processes for detecting cyber–physical attacks. A cyber–physical attack scenario is presented with preliminary results to illustrate how the system can be used.

scholarly journals Modelling and evaluation of multi-state reliability of repairable non-series manufacturing system with finite buffers

2019 ◽  
Vol 11 (6) ◽  
pp. 168781401985548 ◽  
Author(s):  
Jianguo Duan ◽  
Nan Xie ◽  
Lianhui Li
Keyword(s):  
Generating Function ◽  
Flexible Manufacturing ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
System Structure ◽  
Function Technique ◽  
Practical Case ◽  
Finite Buffers ◽  
Measurement Models ◽  
Universal Generating Function

The capacity and capability of flexible manufacturing system varies with different market demands. To satisfy the requirements of performance expressions, avoid the problem of combinatorial explosion and consider the influence of intermediate buffer stations, a new reliability modelling and evaluating methodology for repairable non-series hybrid flexible manufacturing systems with finite buffers is proposed using an extended vector universal generating function technique. For repairable modular machines, the Markov models of modular machines are established using stochastic process analysis and the corresponding theoretical steady-state probability in various states is obtained. Furthermore, the original system in combination with multi-state reliability measures of buffer stations is equivalent to a system with independent machines which can be expressed by vector u-functions. Based on the probability distributions of the states of subsystems, the composition operators for series connections and parallel connections are defined. Consequently, the entire system is simplified to one component represented by the polynomial universal generating function. In particular, reliability indicators and measurement models are given to assess the system’s reliability through promoting the basic ones. Finally, a practical case of engine head machining line is utilized to verify the effectiveness of the method. The results demonstrate that the use of vector universal generating functions can describe the system structure and states more appropriately while providing efficient assessment.

Virtual Manufacturing and Its Application to Making Oil Pumps

Manufacturing ◽  
2002 ◽  
Author(s):  
A. A. Tseng ◽  
J. Q. Yan ◽  
X. M. Fan ◽  
D. Z. Ma
Keyword(s):  
Information Processing ◽  
Manufacturing Systems ◽  
Manufacturing Industry ◽  
Manufacturing System ◽  
Virtual Manufacturing ◽  
System Structure ◽  
System Architectures ◽  
Software Applications ◽  
Prototype Software ◽  
Processing Techniques

Advances in manufacturing systems have led to the increasing importance of the information processing techniques. Many tasks in manufacturing have been transferred from workshops to computers, and now large portions of activities in manufacturing systems are presently considered for being carried out as information processing activities within computers. As a result, system architectures and virtual reality have emerged as necessary components in today’s global manufacturing industry in an attempt to enhance both process and production operations. A system structure and related design methodology of a general virtual manufacturing system is proposed here. Prototype software based on the proposed system has been developed. The system was developed on a network-based platform, which can integrate with wide variety of software. Applications of the proposed system to virtual product design of oil pumps are then presented to demonstrate its feasibility and versatility.

A Study of Flexible Manufacturing System With Multiple Failures

2018 ◽  
pp. 96-117
Author(s):  
Monika Manglik ◽  
Mangey Ram ◽  
Divya Ahluwalia
Keyword(s):  
Markov Process ◽  
Flexible Manufacturing ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Flexible Manufacturing System ◽  
System Structure ◽  
Mathematical Framework ◽  
Supplementary Variable ◽  
Laplace Transformations ◽  
Reliability And Availability

Flexibility refers to the capability of a manufacturing system to respond cost effectively and arbitrarily to adapting production needs and necessities. This ability is becoming increasingly important for the design and operation of manufacturing systems, as these systems do function in highly variable and unpredictable environments. In this chapter, the reliability of the flexible manufacturing system has been calculated based on the mathematical framework. The model of the system consists of the system structure and the distribution of its components. The components are assumed to be repairable after various types of failures. In this work, the reliability and availability have been analyzed by using Markov process, Laplace transformations and supplementary variable techniques. Furthermore, the impacts of various failures on reliability, and availability of the system have also been analyzed.

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