scholarly journals An Efficient Library for Reliability Block Diagram Evaluation

2021 ◽  
Vol 11 (9) ◽  
pp. 4026
Author(s):  
Laura Carnevali ◽  
Lorenzo Ciani ◽  
Alessandro Fantechi ◽  
Gloria Gori ◽  
Marco Papini
Keyword(s):  
Complex Systems ◽  
System Reliability ◽  
Block Diagram ◽  
Reliability Evaluation ◽  
Time Dependent ◽  
Reliability Engineering ◽  
Reliability Block Diagrams ◽  
Layered Approach ◽  
Modeling Formalisms ◽  
Better Than

Reliability Block Diagrams (RBDs) are widely used in reliability engineering to model how the system reliability depends on the reliability of components or subsystems. In this paper, we present librbd, a C library providing a generic, efficient and open-source solution for time-dependent reliability evaluation of RBDs. The library has been developed as a part of a project for reliability evaluation of complex systems through a layered approach, combining different modeling formalisms and solution techniques at different system levels. The library achieves accuracy and efficiency comparable to, and mostly better than, those of other well-established tools, and it is well designed so that it can be easily used by other libraries and tools.

Fault Tree Analysis for Reliability Evaluation of an Advanced Complex Manufacturing System

2018 ◽  
Vol 17 (01) ◽  
pp. 107-118 ◽  
Author(s):  
Hamed Fazlollahtabar ◽  
Seyed Taghi Akhavan Niaki
Keyword(s):  
System Reliability ◽  
Material Handling ◽  
Manufacturing System ◽  
Block Diagram ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Reliability Evaluation ◽  
Industrial Robots ◽  
Tree Analysis ◽  
Minimal Paths

In this paper, minimal paths and cuts technique is developed to handle fault tree analysis (FTA) on the critical components of industrial robots. This analysis is integrated with the reliability block diagram (RBD) approach in order to investigate the robot system reliability. The model is implemented in a complex advanced manufacturing system having autonomous guided vehicles (AGVs) as material handling devices. FTA grants cause and effects and hierarchical properties to the model. On the other hand, RBD simplifies the complex system of the AGVs for reliability evaluation. The results show that due to the filtering of the paths in a manufacturing system for AGVs, the reliability is highly dependent on the mostly occupied paths by AGVs. The failure probability for the AGV is considered to follow the exponential probability distribution and thus the whole system reliability using minimal paths and cuts method is obtained 0.8741.

Integration of fault tree analysis, reliability block diagram and hazard decision tree for industrial robot reliability evaluation

2017 ◽  
Vol 44 (6) ◽  
pp. 754-764 ◽  
Author(s):  
Hamed Fazlollahtabar ◽  
Seyed Taghi Akhavan Niaki
Keyword(s):  
Decision Tree ◽  
Complex Systems ◽  
Block Diagram ◽  
Fault Tree Analysis ◽  
Reliability Evaluation ◽  
Industrial Robots ◽  
Robot System ◽  
Tree Analysis ◽  
Content Type ◽  
Critical Components

Purpose This paper aims to conduct a comprehensive fault tree analysis (FTA) on the critical components of industrial robots. This analysis is integrated with the reliability block diagram (RBD) approach to investigate the robot system reliability. Design/methodology/approach For practical implementation, a particular autonomous guided vehicle (AGV) system was first modeled. Then, FTA was adopted to model the causes of failures, enabling the probability of success to be determined. In addition, RBD was used to simplify the complex system of the AGV for reliability evaluation purpose. Findings Hazard decision tree (HDT) was configured to compute the hazards of each component and the whole AGV robot system. Through this research, a promising technical approach was established, allowing decision-makers to identify the critical components of AGVs along with their crucial hazard phases at the design stage. Originality/value As complex systems have become global and essential in today’s society, their reliable design and determination of their availability have turned into very important tasks for managers and engineers. Industrial robots are examples of these complex systems that are being increasingly used for intelligent transportation, production and distribution of materials in warehouses and automated production lines.

Modeling System Reliability Using a Nonparametric Method

2014 ◽  
Vol 687-691 ◽  
pp. 1193-1197
Author(s):  
Wei Zhen You ◽  
Xiao Pin Zhong
Keyword(s):  
Complex Systems ◽  
Failure Rate ◽  
System Reliability ◽  
Parametric Models ◽  
Nonparametric Model ◽  
System Failure ◽  
Nonparametric Method ◽  
Reliability Engineering ◽  
Gaussian Smoothing

System reliability is an important problem especially in reliability engineering. The frequency a system failure happens is represented by failure rate. We use failure rate instead of system reliability to analyze a particular system.Traditional parametric models cannot give a good fit to complex systems, wetherefore employed a nonparametric method in this paper. Gaussian smoothing is also applied on the failure rate curves. Compared with parametric models, the nonparametric model yields more accurateestimation of system failure rate.

AN EFFICIENT MULTI-VARIABLE INVERSION ALGORITHM FOR RELIABILITY EVALUATION OF COMPLEX SYSTEMS USING PATH SETS

2002 ◽  
Vol 09 (03) ◽  
pp. 237-259 ◽  
Author(s):  
S. K. CHATURVEDI ◽  
K. B. MISRA
Keyword(s):  
Complex Systems ◽  
System Reliability ◽  
Computing System ◽  
Reliability Evaluation ◽  
Compact Form ◽  
Connection Matrix ◽  
Inversion Algorithm ◽  
Minimal Path ◽  
Matrix Operations ◽  
Minimal Path Sets

Reliability evaluation of a large and complex system is quite an involved and time-consuming process and its state-of-art is far from being called as satisfactory. This is mainly due to the fact that unionizing path sets results in large number of terms in the reliability expression. Thereafter, the process of computing numerical value of system reliability from its expression is a task not free from the build up of round-off errors. The entire process also restricts the use of a low-end PC for computing system reliability of such systems. In this paper, we propose an efficient methodology to evaluate reliability of large and complex systems based on minimal path sets; the path sets enumeration procedure used in this paper generates path sets in lexicographic and increasing order of cardinality — a condition, which is helpful in obtaining sum of disjoint products (SDP) of the system reliability expression in a compact form. Although we make use of the system connection matrix but no complicated matrix operations are performed to obtain the results. The paper further presents an improved multi-variable inversion (MVI) algorithm to evaluate system reliability in a compact form. Our approach offers an extensive reduction in the number of mutually disjoint terms and provides a minimized and compact system reliability expression. The procedure not only results in substantial saving of CPU time but also can be run on a low-end PC. To demonstrate this capability, we solve several problems of varied complexities on a low-end PC and also provide a comparison of our approach with earlier techniques available for the purpose.

scholarly journals On investigation of the Bayesian anomaly in multiple imprecise dependent information aggregation for system reliability evaluation

2021 ◽  
Vol 36 (6) ◽  
pp. 2895-2921
Author(s):  
Lechang Yang ◽  
Pidong Wang ◽  
Wenhua Zhao ◽  
Chenxing Wang ◽  
Xiuli Wu ◽  
...  
Keyword(s):  
System Reliability ◽  
Information Aggregation ◽  
Reliability Evaluation

scholarly journals Diffusion in CP Stars: The Quest for Accuracy

1998 ◽  
Vol 11 (2) ◽  
pp. 671-673
Author(s):  
G. Alecian
Keyword(s):  
Computational Methods ◽  
Stellar Evolution ◽  
Diffusion Processes ◽  
Stellar Atmospheres ◽  
Time Dependent ◽  
Data Bases ◽  
Self Consistent ◽  
Stellar Envelopes ◽  
Better Than

We present a brief review about recent progresses concerning the study of diffusion processes in CP stars. The most spectacular of them concerns the calculation of radiative accelerations in stellar envelopes for which an accuracy better than 30% can now be reached for a large number of ions. This improvement is mainly due to huge and accurate atomic and opacity data bases available since the beginning of the 90’s. Developments of efficient computational methods have been carried out to take advantage of these new data. These progresses have, in turn, led to a better understanding of how the element stratification is building up with time. A computation of self-consistent stellar evolution models, including time-dependent diffusion, can now be within the scope of the next few years. However, the progresses previously mentioned do not apply for stellar atmospheres and upper layers of envelopes.

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