The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Philippe Charpentier - One of the best experts on this subject based on the ideXlab platform.
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feasibility study and uncertainties in the validation of an existing Safety related control circuit with the iso 13849 1 2006 design standard
Reliability Engineering & System Safety, 2014Co-Authors: Sabrina Jocelyn, James Baudoin, Yuvin Chinniah, Philippe CharpentierAbstract:In industry, machine users and people who modify or integrate equipment often have to evaluate the Safety level of a Safety-related control circuit that they have not necessarily designed. The modifications or integrations may involve work to make an existing machine that does not comply with normative or regulatory specifications safe. However, how can a circuit performing a Safety Function be validated a posteriori? Is the validation exercise feasible? What are the difficulties and limitations of such a procedure? The aim of this article is to answer these questions by presenting a validation study of a Safety Function of an existing machine. A plastic injection molding machine is used for this study, as well as standard ISO 13849-1:2006. Validation consists of performing an a posteriori (post-design) estimation of the performance level of the Safety Function. The procedure is studied for two contexts of use of the machine: in industry, and in laboratory. The calculations required by the ISO standard were done using Excel, followed by SIStema software. It is shown that, based on the context of use, the estimated performance level was different for the same Safety-related circuit. The variability in the results is explained by the assumptions made by the person undertaking the validation without the involvement of the machine designer.
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feasibility study and uncertainties in the validation of an existing Safety related control circuit with the iso 13849 1 2006 design standard
Reliability Engineering & System Safety, 2014Co-Authors: Sabrina Jocelyn, James Baudoin, Yuvin Chinniah, Philippe CharpentierAbstract:In industry, machine users and people who modify or integrate equipment often have to evaluate the Safety level of a Safety-related control circuit that they have not necessarily designed. The modifications or integrations may involve work to make an existing machine that does not comply with normative or regulatory specifications safe. However, how can a circuit performing a Safety Function be validated a posteriori? Is the validation exercise feasible? What are the difficulties and limitations of such a procedure? The aim of this article is to answer these questions by presenting a validation study of a Safety Function of an existing machine. A plastic injection molding machine is used for this study, as well as standard ISO 13849-1:2006. Validation consists of performing an a posteriori (post-design) estimation of the performance level of the Safety Function. The procedure is studied for two contexts of use of the machine: in industry, and in laboratory. The calculations required by the ISO standard were done using Excel, followed by SIStema software. It is shown that, based on the context of use, the estimated performance level was different for the same Safety-related circuit. The variability in the results is explained by the assumptions made by the person undertaking the validation without the involvement of the machine designer.
Georg Frey - One of the best experts on this subject based on the ideXlab platform.
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Verification and validation of Safety applications based on PLCopen Safety Function blocks
Control Engineering Practice, 2011Co-Authors: Doaa Soliman, Georg FreyAbstract:Abstract Functional Safety is a major concern in the design of automation systems today. Many of those systems are realized using Programmable Logic Controllers (PLCs) programmed according to IEC 61131-3. PLCopen – as IEC 61131 user organization – semi-formally specified a set of software Function blocks to be used in Safety applications according to IEC 61508. In the presented work, formal models in the form of timed automata for the Safety Function blocks (SFBs) are constructed from the semi-formal specifications. The accordance of the formalized blocks to the specification is verified using model checking. Furthermore, their behaviour is validated against specified test cases by simulation. The resulting verified and validated library of formal models is used to build a formal model of a given Safety application – built from SFBs – and to verify and validate its properties.
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Verification and Validation of Safety Applications based on PLCopen Safety Function Blocks using Timed Automata in Uppaal
IFAC Proceedings Volumes, 2009Co-Authors: Doaa Soliman, Georg FreyAbstract:Functional Safety is a major concern in the design of automation systems today. Many of those systems are realized using PLCs programmed according to IEC 61131–3. PLCopen as IEC 61131 user organization specified a set of software Function Blocks to be used in Safety Applications according to IEC 61508 in 2006. The specification of Technical Committee 5 contains twenty Safety Function Blocks (SFBs) as a library together with some specifications of their use. A second part issued in 2008 demonstrates the use of the defined SFBs in real applications. In the presented work, formal models for the SFBs are derived from the semi-formal specification in the PLCopen documents. Those blocks are verified using model checking and the accordance of their temporal behavior with the PLCopen specification is further validated by simulation. The resulting library of formal models allows to build a formal model of a given Safety application – built from SFBs – and to verify its properties. This is demonstrated using an example from the second part of the PLCopen specification.
Sabrina Jocelyn - One of the best experts on this subject based on the ideXlab platform.
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feasibility study and uncertainties in the validation of an existing Safety related control circuit with the iso 13849 1 2006 design standard
Reliability Engineering & System Safety, 2014Co-Authors: Sabrina Jocelyn, James Baudoin, Yuvin Chinniah, Philippe CharpentierAbstract:In industry, machine users and people who modify or integrate equipment often have to evaluate the Safety level of a Safety-related control circuit that they have not necessarily designed. The modifications or integrations may involve work to make an existing machine that does not comply with normative or regulatory specifications safe. However, how can a circuit performing a Safety Function be validated a posteriori? Is the validation exercise feasible? What are the difficulties and limitations of such a procedure? The aim of this article is to answer these questions by presenting a validation study of a Safety Function of an existing machine. A plastic injection molding machine is used for this study, as well as standard ISO 13849-1:2006. Validation consists of performing an a posteriori (post-design) estimation of the performance level of the Safety Function. The procedure is studied for two contexts of use of the machine: in industry, and in laboratory. The calculations required by the ISO standard were done using Excel, followed by SIStema software. It is shown that, based on the context of use, the estimated performance level was different for the same Safety-related circuit. The variability in the results is explained by the assumptions made by the person undertaking the validation without the involvement of the machine designer.
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feasibility study and uncertainties in the validation of an existing Safety related control circuit with the iso 13849 1 2006 design standard
Reliability Engineering & System Safety, 2014Co-Authors: Sabrina Jocelyn, James Baudoin, Yuvin Chinniah, Philippe CharpentierAbstract:In industry, machine users and people who modify or integrate equipment often have to evaluate the Safety level of a Safety-related control circuit that they have not necessarily designed. The modifications or integrations may involve work to make an existing machine that does not comply with normative or regulatory specifications safe. However, how can a circuit performing a Safety Function be validated a posteriori? Is the validation exercise feasible? What are the difficulties and limitations of such a procedure? The aim of this article is to answer these questions by presenting a validation study of a Safety Function of an existing machine. A plastic injection molding machine is used for this study, as well as standard ISO 13849-1:2006. Validation consists of performing an a posteriori (post-design) estimation of the performance level of the Safety Function. The procedure is studied for two contexts of use of the machine: in industry, and in laboratory. The calculations required by the ISO standard were done using Excel, followed by SIStema software. It is shown that, based on the context of use, the estimated performance level was different for the same Safety-related circuit. The variability in the results is explained by the assumptions made by the person undertaking the validation without the involvement of the machine designer.
Juraj Zdansky - One of the best experts on this subject based on the ideXlab platform.
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Influence of Architecture and Parameters of SRCS on Safety Function Response Time
2020 ELEKTRO, 2020Co-Authors: Juraj Zdansky, Jozef Valigursky, Milan MedvedikAbstract:Response time is one of the most important parameter of Safety Functions for Safety Related Control System (SRCS) in time critical applications. During realization of this Safety Function for response time optimization, detailed knowledge of factors which have influence on response time is unavoidable. This contribution deals with analysis of measured response time reached by various SRCS architectures. These architectures are various in parameters settings, used hardware and used communication network. Final analysis shows influence of above described aspects on SF response time, what can be helpful for suitable architecture choose and parameters optimization when SF with SRCS is realized.
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The Problems Related to Realization of Safety Function with SIL4 Using PLC
2020 Cybernetics & Informatics (K&I), 2020Co-Authors: Karol Rastocny, Juraj Zdansky, Jozef HrbcekAbstract:Safety PLCs are currently a common tool for realizing Safety Functions in industrial applications. Commercially available Safety PLCs enables the realization of Safety Functions with a maximum of SIL (Safety Integrity Level) 3 without additional measures. However, the guaranteed Safety features of Safety PLCs create the preconditions for their usage even in applications where the use of Safety PLC has not been common. This paper aims to point out the problems related to the use of Safety PLC to realize Safety Functions with SIL 4.
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time response of Safety Function realised by decentralised srcs with Safety plc
International Conference on Applied Electronics, 2018Co-Authors: Juraj Zdansky, Jozef ValigurskyAbstract:Guaranteed response time of a control system is a primary assumption for correct Function of the system. This parameter is ever more important in case of a Safety related control systems (SRCS). We have to determine a maximal response time of the realised Safety Functions to reach required Safety parameters (it means that we have to assume the worst case of SRCS behaviour). This time depends not only on parameters of the SRCS but also on its architecture. This paper deals with influence ofthe above mentioned factors to response time of Safety Functions realised by a decentralised SRCS.
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hazardous failure rate of the Safety Function
International Conference on Transport Systems Telematics, 2015Co-Authors: Karol Rastocny, Juraj ZdanskyAbstract:Quantitative assessment of Safety Function integrity against random failures is necessary assumption for railway signalling system acceptance and its implementation into operation. The railway signalling system can be modelled as continuous mode system and therefore the criterion for quantitative assessment Safety integrity of Safety Function is hazardous failure rate. Most of commonly available software tools for evaluation of the RAMS parameters offer calculation of Safety Function failure probability, but don’t offer direct calculation of Safety Function failure rate. The paper is focused on some of problems associated with comparing the exact analytical solution and approximate calculation of Safety Function failure rate due to presence of random failures. This approach can be successfully applied to “manual” calculation of also complex analytical terms. The proposed method is based on the generally accepted assumption that occurrence of random failures of electronic systems corresponds to an exponential distribution law.
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TST - Hazardous Failure Rate of the Safety Function
Communications in Computer and Information Science, 2015Co-Authors: Karol Rastocny, Juraj ZdanskyAbstract:Quantitative assessment of Safety Function integrity against random failures is necessary assumption for railway signalling system acceptance and its implementation into operation. The railway signalling system can be modelled as continuous mode system and therefore the criterion for quantitative assessment Safety integrity of Safety Function is hazardous failure rate. Most of commonly available software tools for evaluation of the RAMS parameters offer calculation of Safety Function failure probability, but don’t offer direct calculation of Safety Function failure rate. The paper is focused on some of problems associated with comparing the exact analytical solution and approximate calculation of Safety Function failure rate due to presence of random failures. This approach can be successfully applied to “manual” calculation of also complex analytical terms. The proposed method is based on the generally accepted assumption that occurrence of random failures of electronic systems corresponds to an exponential distribution law.
Doaa Soliman - One of the best experts on this subject based on the ideXlab platform.
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Verification and validation of Safety applications based on PLCopen Safety Function blocks
Control Engineering Practice, 2011Co-Authors: Doaa Soliman, Georg FreyAbstract:Abstract Functional Safety is a major concern in the design of automation systems today. Many of those systems are realized using Programmable Logic Controllers (PLCs) programmed according to IEC 61131-3. PLCopen – as IEC 61131 user organization – semi-formally specified a set of software Function blocks to be used in Safety applications according to IEC 61508. In the presented work, formal models in the form of timed automata for the Safety Function blocks (SFBs) are constructed from the semi-formal specifications. The accordance of the formalized blocks to the specification is verified using model checking. Furthermore, their behaviour is validated against specified test cases by simulation. The resulting verified and validated library of formal models is used to build a formal model of a given Safety application – built from SFBs – and to verify and validate its properties.
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Verification and Validation of Safety Applications based on PLCopen Safety Function Blocks using Timed Automata in Uppaal
IFAC Proceedings Volumes, 2009Co-Authors: Doaa Soliman, Georg FreyAbstract:Functional Safety is a major concern in the design of automation systems today. Many of those systems are realized using PLCs programmed according to IEC 61131–3. PLCopen as IEC 61131 user organization specified a set of software Function Blocks to be used in Safety Applications according to IEC 61508 in 2006. The specification of Technical Committee 5 contains twenty Safety Function Blocks (SFBs) as a library together with some specifications of their use. A second part issued in 2008 demonstrates the use of the defined SFBs in real applications. In the presented work, formal models for the SFBs are derived from the semi-formal specification in the PLCopen documents. Those blocks are verified using model checking and the accordance of their temporal behavior with the PLCopen specification is further validated by simulation. The resulting library of formal models allows to build a formal model of a given Safety application – built from SFBs – and to verify its properties. This is demonstrated using an example from the second part of the PLCopen specification.
