Pam Binns

DOMAIN-SPECIFIC SOFTWARE ARCHITECTURES FOR GUIDANCE, NAVIGATION AND CONTROL

We describe two languages and associated tools for capturing and analyzing two different views of the architecture of an embedded system. One language is tailored to address guidance, navigation, and feedback control issues, while the other is tailored to address real-time, fault-tolerance, secure partitioning, and scalable multiprocessor issues. Both languages have tools that perform analyses appropriate for the issues each addresses, and tools to automatically configure the application software from a sufficiently detailed specification. The integrated languages and tools are intended to support a development process based on reusing an easily configurable generic architecture developed for a family of products.

Scheduling and communication in MetaH

This paper describes certain aspects of an architecture description language (MetaH) and associated toolset used to specify, analyze, and automatically assemble software for real-time, fault-tolerant, secure, multi-processor systems. One goal in the design of this language and toolset was to provide design-time analysis that accurately characterizes the behavior of the actual implementation. Currently, our toolset consists of tools to automatically assemble the application software and to perform a real-time schedulability analysis for that application.<<ETX>>

Formalizing Software Architectures for Embedded Systems

This paper outlines an approach to embedded computer system development that is based on integrated use of multiple domainspecific languages; on increased use of mathematical analysis methods; and on increased integration between domain-specific specification and mathematical modeling and code generation. We first outline some general principles of this approach. We then present a bit more detail about the emerging SAE standard Avionics Architecture Description Language and our supporting MetaH toolset.We conclude with a summary of some research challenge problems, technical approaches, and preliminary results uncovered during our work.

Hierarchical Composition and Abstraction in Architecture Models

We present a compositional approach to generate linear hybrid automata timing models, and Markovian stochastic automata safety models, from an architecture specification. Formal models declared for components are composed to form an overall model for the system, where the composition rules depend on the semantics of the architecture specification. We further allow abstract models to be specified for a subsystem of components, where the abstract model may be substituted for the concrete model of that subsystem when composing the overall system model. We assume both abstract and concrete models are given, we address the problem of verifying that the abstractions yield safe if approximate results. An abstract model may be viewed as a formal subsystem specification used for both conformance checking and improving the tractability of system analysis.

Statistical verification of two non-linear real-time UAV controllers

We present a versatile statistical verification methodology and we illustrate different uses of this methodology on two examples of nonlinear real-time UAV controllers. The first example applies our statistical methodology to the verification of a computation time property for a software implementation of a high-performance controller as a function of controller state variable values. The second example illustrates our statistical verification methodology applied to finding verifiably safe flight envelopes for a class of maneuvers, again as a function of controller state variable values. We compare our approach to verification with other statistical techniques used for estimating execution times and controller performance. We close with candidate topics for future work.