Search Results

A hybrid discrete/continuous simulation tool, CONFIG, has been developed to support evaluation of the operability of life support systems. CONFIG simulates operations scenarios in which continuous change in system flows and pressures interacts with discrete events during system reconfigurations. In simulation, intelligent control software interacts dynamically with a model of the hardware system. CONFIG simulations have been used to evaluate control software and intelligent agents for automating life support systems operations. A CONFIG model of an advanced biological water recovery system has been developed to interact with intelligent control software that is being used in a water system test at NASA Johnson Space Center.

Gas transfer systems in a closed life support test were controlled by intelligent layered monitoring and control software. Interactive simulation-based testing was used for system-level validation of the discrete sequencer layer of the software. An advanced discrete event simulation tool was used to model diverse components and systems for processing gases in a plant growth chamber, crew chamber and incinerator, and transferring gases between chambers. Models included physico-chemical and biological gas processors, pumps, concentrators, chambers and tanks, and devices for configuring and controlling gas transfer. Several types of control were modeled. This paper describes the models, the testing approach, and some results of the testing.