Systems Status

Requirements Summary

The  Systems Status (SS) module, like the Situation Assessment module, underwent significant change to its contribution to the operation of the PA.  In the early stages, it we seen as a grab bag of technologies being thrown at an enormous problem.  Once scoped down to the essentials, however, it became an ingredient essential to the operation of the rest of the PA. The SS module was responsible for:

• receiving "raw" input data from this aircraft and its wingmen,
• interpreting that data in terms of the ability of this aircraft and the members of its flight to complete the current mission,
• maintaining a stable, dynamic view of the state of the friendly assets including this aircraft, 
• recommend to the pilot actions that might eliminate or alleviate detected problems,
• monitor the effectiveness of the remedial actions if performed,
• responding to specific requests for information, and
• ensuring that the planning and PVI modules were aware of the current situation.  

Phase 1 Implementation

The SS was originally implemented in Phase 1 in KEE, the Knowledge Engineering Environment. It was intended to diagnose and if possible remedy engine malfunctions using model-based reasoning and analysis.  Requests for fuel consumption information, and analysis of incoming engine data required extensive analysis and modeling.  It was quickly realized that this was not providing timely information, and was not treating the status of other systems.  By the end of Phase 1, SS was coded in Lisp using a causal network to propagate the effects of changes in raw sensor data to their impact on the mission.  Engine analysis was delegated to the on-board engine processors, received in the form of built-in test (BIT) codes.  Fuel consumption was determined by table lookup, and all other major avionics systems were providing BIT codes.

Phase 2 Implementation

In Phase 2, the SS subsystem was recoded in C++.  Its responsibility remained unchanged, and it was able to ensure that the planners never considered plans for which the aircraft did not have the resources.

last updated 1/26/2003 by David Smith