---
title: "A Fault Detection and Isolation Method Applied to Liquid Oxygen Loading for the Space Shuttle"
authors:
  - "Ethan A. Scarl"
  - "John R. Jamieson"
  - "Carl I. Delaune"
doi: ""
url: "https://ijcai.org/proceedings/1985/79"
pdf: "https://ijcai.org/proceedings/1985/0079.pdf"
venue: "Proceedings of the Ninth International Joint Conference on Artificial Intelligence"
year: 1985
pages: "414-415"
track: "Expert Systems"
keywords:
---

# A Fault Detection and Isolation Method Applied to Liquid Oxygen Loading for the Space Shuttle

Ethan A. Scarl, John R. Jamieson, Carl I. Delaune

*Proceedings of the Ninth International Joint Conference on Artificial Intelligence*, pages 414-415.

## Abstract

Process-monitoring and fault lo catio n techniqu es have been developed at the Kennedy Space Center in a domain of mixed med ia control in NASA's Space Shuttl e Launch Processing System. An intuitively appealing diagno stic technique and representation of the system's str ucture and function were formulated in coop e ration with system engineers . Functional relationships that d ete rmine the consistency of sensor me asurements are represented by sy mbolic expressions e mb edded in frames. Functional relationships are st or e d in exactly one place, so they must be inverted to de termine hypoth etica l values for possibly faulty objects. Propagating thes e hypoth e ti cal sta tes to other se n sors permits the lo cation of faults. Standard sy mbolic inv ersion techniques have be e n ex t en d e d to include con diti onal functions. A demonstration system is operating, and lts evaluaticn will soon use live data from th e firing rooms a t KSC.