Modeling, Design and Simulation of a Reconfigurable Aquatic Habitat for Life Support Control Research

Presented at the 41st AIAA International Conference on Environmental Systems (ICES), 17-21 July 2011, Portland, Oregon.This paper presents the design, modeling, and simulation of a reconfigurable aquatic habitat for experiments in regenerative life support automation; it supports the use of aquatic habitats as a small-scale approach to automation experiments relevant to larger- scale regenerative life support systems. The habitat consists of a ten-gallon tank with four compartments, containing animal and botanical elements. The water volume serves as the medium through which life-support compounds, like oxygen, are transferred between organisms. A motorized hatch allows reconfiguration of the system to allow or prevent the exchange of gases with the atmosphere, and enables the study of fail-safe automation mechanisms. Sensors and actuators measure and intervene to regulate life support variables in the water. The model serves as an analytical reference for future tests in hardware settings, and to test advanced control architectures and policies that enable the system to operate safely and with increasing levels of autonomy, allowing for human intervention if necessary. The goal of the aquatic habitat is to enable life support control concepts that may be challenging to test in larger-scale life support systems. The mathematical description of the dynamic model of the system is presented in this paper with results from simulations of a distributed control approach applied to the habitat