In conjunction with the working characteristics of the high-clearance wheeled sprayer and the benefits of the closed hydraulic system,a series of reasonable working parameters should be established,and a hydraulic sys...In conjunction with the working characteristics of the high-clearance wheeled sprayer and the benefits of the closed hydraulic system,a series of reasonable working parameters should be established,and a hydraulic system that fulfills the requisite specifications should be designed.The AMESim software model is employed to construct a closed hydraulic transmission system,and the simulation analysis is then performed according to the data of hydraulic components.According to analysis results,the prototype can be optimized and upgraded,and a verification test is further carried out.The test results demonstrate that the designed closed hydraulic transmission system meets the actual working requirements of the high-clearance wheeled sprayer and provides a stable experimental platform for intelligent control of agricultural machinery.展开更多
Modeling and simulation(M&S)play a critical role in both engineering and basic research processes.Computer-based models have existed since the 1950s,and those early models have given way to the more complex comput...Modeling and simulation(M&S)play a critical role in both engineering and basic research processes.Computer-based models have existed since the 1950s,and those early models have given way to the more complex computational and physics-based simula-tions used today.As such,a great deal of research has been done to establish what level of trust should be given to simulation outputs and how to verify and validate the mod-els used in these simulations.This paper presents an overview of the theoretical work done to date defining formal definitions for,and methods of,verification and validation(V&V)of computer models.Simulation models are broken down into three broad cate-gories:analytical and simulation models,computational and physics-based models,and simulations of autonomous systems,and the unique theories and methods developed to address V&V of these models are presented.This paper also presents the current prob-lems in the theoretical field of V&V for models as simulations move from single system models and simulations to more complex simulation tools.In particular,this paper high-lights the lack of agreed-upon methods for V&V of simulations of autonomous systems,such as an autonomous unmanned vehicles,and proposes some next steps needed to address this problem.展开更多
To better utilize the potential of system simulation models and simulators,industrially applicable methods for Verification,Validation and Uncertainty Quantification(VV&UQ)are crucial.This paper presents an explo...To better utilize the potential of system simulation models and simulators,industrially applicable methods for Verification,Validation and Uncertainty Quantification(VV&UQ)are crucial.This paper presents an exploratory case study of VV&UQ techniques applied on models integrated in aircraft system simulators at Saab Aeronautics and in driving simulators at the Swedish National Road and Transport Research Institute(VTI).Results show that a large number of Verification and Validation(V&V)techniques are applied,some of which are promising for further development and use in simulator credibility assessment.Regarding the application of UQ,a large gap between academia and this part of industry has been identified,and simplified methods are needed.The applicability of the NASA Credibility Assessment Scale(CAS)at the studied organizations is also evaluated and it can be concluded that the CAS is considered to be a usable tool for achieving a uniform level of V&V for all models included in a simulator,although its implementation at the studied organizations requires tailoring and coordination.展开更多
When building dependable systems by integrating untrusted software components that were not originally designed to interact with each other, it is likely the occurrence of architectural mismatches related to assumptio...When building dependable systems by integrating untrusted software components that were not originally designed to interact with each other, it is likely the occurrence of architectural mismatches related to assumptions in their failure behaviour. These mismatches, if not prevented during system design, have to be tolerated during runtime. This paper presents an architectural abstraction based on exception handling for structuring fault-tolerant software systems. This abstraction comprises several components and connectors that promote an existing untrusted software element into an idealised fault-tolerant architectural element. Moreover, it is considered in the context of a rigorous software development approach based on formal methods for representing the structure and behaviour of the software architecture. The proposed approach relies on a formal specification and verification for analysing exception propagation, and verifying important dependability properties, such as deadlock freedom, and scenarios of architectural reconfiguration. The formal models are automatically generated using model transformation from UML diagrams： component diagram representing the system structure, and sequence diagrams representing the system behaviour. Finally, the formal models are also used for generating unit and integration test cases that are used for assessing the correctness of the source code. The feasibility of the proposed architectural approach was evaluated on an embedded critical case study.展开更多
In this paper,we propose an approach to formally verify and rigorously validate a simulation system against the specification of the real system.We implement the approach in a verification and validation calculator to...In this paper,we propose an approach to formally verify and rigorously validate a simulation system against the specification of the real system.We implement the approach in a verification and validation calculator tool that takes as input a set of statements that capture the requirements,internal conditions of the system and expected outputs of the real system and produces as output whether the simulation satisfies the requirements,faithfully represents the internal conditions of the system and produces the expected outputs.We provide a use case to show how subject matter experts can apply the tool.展开更多
基金Supported by 2023 Xinjiang Uygur Autonomous Region R&D and Promotion and Application of Key Technologies of CNC Sprayer for Seed Corn(2023NC010).
文摘In conjunction with the working characteristics of the high-clearance wheeled sprayer and the benefits of the closed hydraulic system,a series of reasonable working parameters should be established,and a hydraulic system that fulfills the requisite specifications should be designed.The AMESim software model is employed to construct a closed hydraulic transmission system,and the simulation analysis is then performed according to the data of hydraulic components.According to analysis results,the prototype can be optimized and upgraded,and a verification test is further carried out.The test results demonstrate that the designed closed hydraulic transmission system meets the actual working requirements of the high-clearance wheeled sprayer and provides a stable experimental platform for intelligent control of agricultural machinery.
文摘Modeling and simulation(M&S)play a critical role in both engineering and basic research processes.Computer-based models have existed since the 1950s,and those early models have given way to the more complex computational and physics-based simula-tions used today.As such,a great deal of research has been done to establish what level of trust should be given to simulation outputs and how to verify and validate the mod-els used in these simulations.This paper presents an overview of the theoretical work done to date defining formal definitions for,and methods of,verification and validation(V&V)of computer models.Simulation models are broken down into three broad cate-gories:analytical and simulation models,computational and physics-based models,and simulations of autonomous systems,and the unique theories and methods developed to address V&V of these models are presented.This paper also presents the current prob-lems in the theoretical field of V&V for models as simulations move from single system models and simulations to more complex simulation tools.In particular,this paper high-lights the lack of agreed-upon methods for V&V of simulations of autonomous systems,such as an autonomous unmanned vehicles,and proposes some next steps needed to address this problem.
基金The research leading to these results has received funding from Saab Aeronautics and the Swedish Government Agency VINNOVA’s National Aviation Engineering Research Programme(NFFP62013-01211).
文摘To better utilize the potential of system simulation models and simulators,industrially applicable methods for Verification,Validation and Uncertainty Quantification(VV&UQ)are crucial.This paper presents an exploratory case study of VV&UQ techniques applied on models integrated in aircraft system simulators at Saab Aeronautics and in driving simulators at the Swedish National Road and Transport Research Institute(VTI).Results show that a large number of Verification and Validation(V&V)techniques are applied,some of which are promising for further development and use in simulator credibility assessment.Regarding the application of UQ,a large gap between academia and this part of industry has been identified,and simplified methods are needed.The applicability of the NASA Credibility Assessment Scale(CAS)at the studied organizations is also evaluated and it can be concluded that the CAS is considered to be a usable tool for achieving a uniform level of V&V for all models included in a simulator,although its implementation at the studied organizations requires tailoring and coordination.
基金supported by Fapesp/Brazil under Grant No. 06/02116-2 and CAPES/Brazil under Grant No. 0722-07-3Cecília Rubira is partially supported by CNPq/Brazil under Grant Nos. 301446/2006-7 and 484138/2006-5
文摘When building dependable systems by integrating untrusted software components that were not originally designed to interact with each other, it is likely the occurrence of architectural mismatches related to assumptions in their failure behaviour. These mismatches, if not prevented during system design, have to be tolerated during runtime. This paper presents an architectural abstraction based on exception handling for structuring fault-tolerant software systems. This abstraction comprises several components and connectors that promote an existing untrusted software element into an idealised fault-tolerant architectural element. Moreover, it is considered in the context of a rigorous software development approach based on formal methods for representing the structure and behaviour of the software architecture. The proposed approach relies on a formal specification and verification for analysing exception propagation, and verifying important dependability properties, such as deadlock freedom, and scenarios of architectural reconfiguration. The formal models are automatically generated using model transformation from UML diagrams： component diagram representing the system structure, and sequence diagrams representing the system behaviour. Finally, the formal models are also used for generating unit and integration test cases that are used for assessing the correctness of the source code. The feasibility of the proposed architectural approach was evaluated on an embedded critical case study.
文摘In this paper,we propose an approach to formally verify and rigorously validate a simulation system against the specification of the real system.We implement the approach in a verification and validation calculator tool that takes as input a set of statements that capture the requirements,internal conditions of the system and expected outputs of the real system and produces as output whether the simulation satisfies the requirements,faithfully represents the internal conditions of the system and produces the expected outputs.We provide a use case to show how subject matter experts can apply the tool.
