Cover image for HRT-HOOD : a structured design method for hard real-time ADA systems
Title:
HRT-HOOD : a structured design method for hard real-time ADA systems
Personal Author:
Series:
Real-time safety critical systems ; v.3
Publication Information:
Amsterdam : Elsevier, 1995
ISBN:
9780444821645
Added Author:

Available:*

Library
Item Barcode
Call Number
Material Type
Item Category 1
Status
Searching...
30000003892415 QA76.73.A35 B87 1995 Open Access Book Book
Searching...

On Order

Summary

Summary

Hardbound. The increasing use of computers for real-time control on board spacecrafts has brought with it a greater emphasis on the development methodology used for such systems. By their nature, spacecraft control computers have to operate unattended for long periods and because of the programmatics of space, systems are subject to a long development cycle. As a result, there are two distinct concerns, the first being that the development approach guarantees functional and timing correctness, the second being that problems, particularly those associated with timing, are considered as early as possible in the spacecraft development life cycle.The European Space Agency has, for a number of years, encouraged the development of software using HOOD. It was thus a natural next step to investigate the incorporation of time within the existing HOOD framework. This has proven to be very beneficial and this book describes the approach developed by the authors f


Table of Contents

Foreword
Preface
Acknowledgements
Real-Time Systems Research at York
Part 1 Hard Real-Time HOOD. Overview of the HRT-HOOD design process
Introduction
The importance of non-functional requirements
The software development life cycle
Summary
Logical and physical architecture design in HRT-HOOD. Logical architecture design
Physical architecture design
Summary
HRT-HOOD objects
Graphical representation
Passive objects
Active objects
Protected objects
Cyclic objects
Sporadic objects
Real-time object attributes
The use relationship (control flow). The include relationship (decomposition). Operation decomposition
Object control structure and thread decomposition
Data flows
Exception flows
Environment objects
Class objects
Distributed systems
Summary
Part 2 Mapping HRT-HOOD Designs to Ada
Supporting hard real-time systems in Ada 83 and Ada 95
The Ada 83 and Ada 95 real-time models
Supporting Ada 95 abstractions in Ada 83
Extending the model
Implementation cost
Summary
Overall mapping approach
HOOD 3.1 to Ada 83 mapping
An alternative translation approach
Mapping HRT-HOOD to Ada
Mapping of passive and active objects
Passive terminal objects
Active terminal objects
Class and instance terminal objects
Mapping protected, cyclic and sporadic objects
Protected terminal objects
Cyclic terminal objects
Sporadic terminal objects
Distributed systems
Analysable communication subsystem
Mapping to Ada 95
Mapping protected objects in a distributed Ada environment
Part 3 Case Studies
The Mine Control System
Mine Control System overview
The logical architecture design
The physical architecture design
The Object Description Skeleton (ODS). Translation to Ada 95
Conclusion
The Olympus Attitude and Orbital Control System (AOCS). Background to the case study
The modelled system: the Olympus AOCS. The software architecture design
The physical architecture design
Problems encountered
Summary
Conclusions
Appendices
A Teminology
B HRT-HOOD definition rules
Design checking, scoping and HRT-Hood rules
General definitions
Use relationship
Include relationships
Operations
Visibility
Consistency
C Object Description Skeleton (ODS) syntax summary
General declarations
Object ODS structure
The visible part of the ODS. The hidden part of the ODS. Parameters of class objects
D Textual formalism - the ODS definition
Passive objects
Active objects
Protected objects
Cyclic objects
Sporadic objects
Environment objects
Class objects
Instances of class objects
E Device control objects in HRT-HOOD. References
Index