Formal Methods Specification and Analysis Guidebook for the Verification of Software and Computer Systems

This guidebook, the second of a two-volume series, is intended to facilitate the transfer of formal methods to the avionics and aerospace community. The 1st volume concentrates on administrative and planning issues [NASA-95a], and the second volume focuses on the technical issues involved in applying formal methods to avionics and aerospace software systems. Hereafter, the term "guidebook" refers exclusively to the second volume of the series. The title of this second volume, A Practitioner's Companion, conveys its intent. The guidebook is written primarily for the nonexpert and requires little or no prior experience with formal methods techniques and tools. However, it does attempt to distill some of the more subtle ingredients in the productive application of formal methods. To the extent that it succeeds, those conversant with formal methods will also nd the guidebook useful. The discussion is illustrated through the development of a realistic example, relevant fragments of which appear in each chapter. The guidebook focuses primarily on the use of formal methods for analysis of requirements and high-level design, the stages at which formal methods have been most productively applied. Although much of the discussion applies to low-level design and implementation, the guidebook does not discuss issues involved in the later life cycle application of formal methods

A component-based virtual engineering approach to PLC code generation for automation systems

In recent years, the automotive industry has been significantly affected by a number of challenges driven by globalisation, economic fluctuations, environmental awareness and rapid technological developments. As a consequence, product lifecycles are shortening and customer demands are becoming more diverse. To survive in such a business environment, manufacturers are striving to find a costeffective solution for fast and efficient development and reconfiguration of manufacturing systems to satisfy the needs of changing markets without losses in production. Production systems within automotive industry are vastly automated and heavily rely on PLC-based control systems. It has been established that one of the major obstacles in realising reconfigurable manufacturing systems is the fragmented engineering approach to implement control systems. Control engineering starts at a very late stage in the overall system engineering process and remains highly isolated from the mechanical design and build of the system. During this stage, control code is typically written manually in vendor-specific tools in a combination of IEC 61131-3 languages. Writing control code is a complex, time consuming and error-prone process. [Continues.

Evaluation of formal IDEs for human-machine interface design and analysis: the case of CIRCUS and PVSio-web

Critical human-machine interfaces are present in many systems including avionics systems and medical devices. Use error is a concern in these systems both in terms of hardware panels and input devices, and the software that drives the interfaces. Guaranteeing safe usability, in terms of buttons, knobs and displays is now a key element in the overall safety of the system. New integrated development environments (IDEs) based on formal methods technologies have been developed by the research community to support the design and analysis of high-confidence human-machine interfaces. To date, little work has focused on the comparison of these particular types of formal IDEs. This paper compares and evaluates two state-of-the-art toolkits: CIRCUS, a model-based development and analysis tool based on Petri net extensions, and PVSio-web, a prototyping toolkit based on the PVS theorem proving system.This work is partially supported by: Project NORTE-01-0145-FEDER-000016, financed by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) PhD scholarship

THE DEVELOPMENT OF A MECHATRONICS AND MATERIAL HANDLING COURSE: LABORATORY EXPERIMENTS AND PROJECTS

Mechatronic systems integrate technologies from a variety of engineering disciplines to create solutions to challenging industrial problems. The material handling industry utilizes mechatronics to move, track, and manipulate items in factories and distribution centers. Material handling systems, because of their use of programmable logic controllers (PLC), PLC networks, industrial robotics, and other mechatronic elements, are a natural choice for a college instructional environment. This thesis offers insight and guidance for mechatronic activities introduced in a laboratory setting. A series of eight laboratory experiments have been created to introduce PLCs, robotics, electric circuits, and data acquisition fundamentals. In-depth case studies synthesize the technologies and interpersonal skills together to create a flexible material handling system. Student response to the course and laboratory material was exceptional. A pre and post course questionnaire was administered which covered topics such as teamwork, human factors, business methods, and various engineering related questions. Quantitative scores resulting from these questionnaires showed a marked improvement by students, especially in regards to technical/engineering questions. The responses from students generally indicated an excitement about course material and a thorough understanding of the various syllabus topics. In this thesis, the multi-disciplinary mechatronics (and material handling systems) laboratory will be presented. An in-depth examination of each laboratory will be offered as well as the discussion of two material handling case studies. The Appendixes contain the PLC and robot code for a order fulfillment case study

Converting LD to SFC (IEC 61131-3)

Ladder Diagram is a simple graphic language useful to express control in terms of a set of boolean predicates that relate input boolean data to output actuation. Although widely used, LD is not properly designed to express sequential logic. To express sequential logic in a clear and structured way we can use SFC. SFC is a graphical language designed to break sequential control into small tasks and can be easily understood upon quick analysis. Since many industrial processes are sequential by nature and there are still many LD programs in the industry, a tool to extract sequential logic from LD programs and represent it in SFC is needed. From this premise, a software tool is developed in Java programming language. This tool takes a project in PLCopen XML format, extracts the LD program and creates the smaller state-space that represents the obfuscated sequential logic. From this state-space a SFC can be built.Ladder Diagram is a simple graphic language useful to express control in terms of a set of boolean predicates that relate input boolean data to output actuation. Although widely used, LD is not properly designed to express sequential logic. To express sequential logic in a clear and structured way we can use SFC. SFC is a graphical language designed to break sequential control into small tasks and can be easily understood upon quick analysis. Since many industrial processes are sequential by nature and there are still many LD programs in the industry, a tool to extract sequential logic from LD programs and represent it in SFC is needed. From this premise, a software tool is developed in Java programming language. This tool takes a project in PLCopen XML format, extracts the LD program and creates the smaller state-space that represents the obfuscated sequential logic. From this state-space a SFC can be built

An approach to impact analysis in software maintenance

Impact analysis is a software maintenance activity, which consists of determining the scope of a requested change, as a basis for planning and implementing it. After a change request has been specified (change understanding) and the initial part of the system to be changed has been identified (change localization), impact analysis helps to understand consequences of the change on other parts of the system. Induced changes, also named ripple effects, among software components are detected. Most existing approaches perform impact analysis for changes occurring at the code level. In this thesis, concepts developed to perform impact analysis at the code level are applied to trace changes occurring at the design level. The method consists of proposing an activity model addressing the different steps of impact analysis and a data model on which propagations of changes can be traced. The method is validated with a case study applied to a system from the aerospace field. The tools we developed on PCTE help for consistency checks in HOOD based designs during editing. Our data-model based on an Entity Relationship notation describes a way to model HOOD diagrams in PCTE and further on to propagate changes on the repository. Examples chosen address the design phase of a simple engine system. We show that addressing modifications at a higher level of abstraction than the code eases understanding and localization of changes. It also limits the propagation of ripple effects (i.e., unexpected behaviour of the system) by detecting secondary changes at an earlier stage

Earth Observatory Satellite system definition study. Report 5: System design and specifications. Volume 5: Specification for EROS operations control center

The functional, performance, and design requirements for the Operations Control Center (OCC) of the Earth Observatory Satellite (EOS) system are presented. The OCC controls the operations of the EOS satellite to acquire mission data consisting of: (1) thematic mapper data, (2) multispectral scanner data on EOS-A, or High Resolution Pointable Imager data on EOS-B, and (3) data collection system (DCS) data. The various inputs to the OCC are identified. The functional requirements of the OCC are defined. The specific systems and subsystems of the OCC are described and block diagrams are provided