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Livingstone2 is a reusable artificial intelligence (AI) software system designed to assist spacecraft, life support systems, chemical plants or other complex systems in operating robustly with minimal human supervision, even in the face of hardware failures or unexpected events. Livingstone2 diagnoses the current state of the spacecraft or other system and recommends commands or repair actions that will allow the system to continue operations.

Livingstone2 is an enhancement and re-engineering of the Livingstone diagnosis system that was flight tested on-board the Deep Space One spacecraft in May 1999. It contains significant enhancements to robustness, performance and usability. Livingstone2 is able to track multiple diagnostic hypotheses, as opposed to a single hypothesis in Livingstone. It is also able to revise diagnostic decisions made in the past when additional observations become available. In such cases, Livingstone might find the incorrect hypothesis. These improvements increase robustness.

Re-architecting and re-implementing the system in C++ has increased performance. Usability has been vastly improved by creating a set of development tools which are closely integrated with the Livingstone2 engine. In addition to the core diagnosis engine, Livingstone2 now includes a compiler than translates diagnostic models written in a Java-like language into Livingstone2's language, and a broad set of graphical tools for model development. These software tools support the rapid deployment of model-based representations of complex systems for Livingstone2 via a visual model builder/tester (Stanley), and two graphical user interface tools (Candidate Manager and History Table) which provide Livingstone2 status information during testing. Runtime support is provided by the real-time interface (RTI) which converts analog sensor readings to the digital values required by Livingstone2.

Also included in the Livingstone2 download is Oliver, a prototype model builder/tester, which is however incomplete, but could be used as a starting place for a new model builder/tester.


Documentation is available here, or here as a downloadable zip.


This software is released under the terms and conditions of the NASA Open Source Agreement (NOSA) Version 1.1 or later.
[Livingstone2 NOSA Software Agreement](../../nosa/livingstone2)
This software is released under the terms and conditions of the NASA Open Source Agreement (NOSA) Version 1.1 or later.
[Real-Time Interface for Livingstone 2 NOSA Software Agreement](../../nosa/livingstone2rti)
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