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We report on a study to determine the maturity of different verification and validation technologies (V&V) on a representative example of NASA flight software. The study consisted of a controlled experiment where three technologies (static analysis, runtime analysis and model checking) were compared to traditional testing with respect to their ability to(More)
In this paper we describe the design and implementation of a static array-bound checker for a family of embedded programs: the flight control software of recent Mars missions. These codes are large (up to 280 KLOC), pointer intensive, heavily multithreaded and written in an object-oriented style, which makes their analysis very challenging. We designed a(More)
This paper describes technology developed for the Am-phion/NAV synthesis system. Building on previous work in Amphion/NAIF, this system synthesizes graduate-level textbook examples of single-mode geometric state estimation software. Amphion/NAV includes explanation technology for mapping the internal representations of a proof (generated through deductive(More)
This paper describes an analysis approach based on a of static and dynamic techniques to ?nd run-time errors in Java code. It uses symbolic execution to ?nd constraints under which an error (<i>e.g.</i> a null pointer dereference, array out of bounds access, or assertion violation) may occur and then solves these constraints to ?nd test inputs that may(More)
—Autonomous 1,2 software, especially if it is based on model, can play an important role in future space applications. For example, it can help streamline ground operations, or, assist in autonomous rendezvous and docking operations, or even, help recover from problems (e.g., planners can be used to explore the space of recovery actions for a power(More)
We present a methodology and a tool for the problem of testing and verifying that a PDDL planning domain satisfies a set of requirements, a need that arises for instance in space missions. We first review and analyse coverage conditions for requirement-based testing, and present how test cases can be derived automatically from requirements. Additionally, we(More)
—Recent 1,2 NASA mission failures (e.g., Mars Polar Lander and Mars Orbiter) illustrate the importance of having an efficient verification and validation process for such systems. One software error, as simple as it may be, can cause the loss of an expensive mission, or lead to budget overruns and crunched schedules. Unfortunately, traditional verification(More)
In this paper, we deene a max-plus algebra of signals for the evaluation of timing behavior of discrete event systems modeled by timed event graphs. We restrict ourselves to innnite, periodic sequences for which we can compute nite representations called signals. This framework allows us to implement a max-plus algebra for computing supremal controllers for(More)