Dynamic Transition to Fallback Operation of Material Circulation Control in Advanced Life Support System using Hierarchical Autonomous Control Method

Advanced life support systems (ALSs) are designed to recycle and circulates materials within a living environment, and are expected to eventually make it possible to sustain life in outer space. This study addresses a subsystem that recycles the elements of carbon, hydrogen, and oxygen, with planned functions that include waste recycling and food production. We have previously proposed a procedure for such a system that combines automatic scheduling generation and multi-agent learning control and is based on a hierarchical control method. In this study, this procedure is used to simulate material circulation subsequent to the malfunction of a processor in the ALS that renders the processor inoperable. Specifically, a six-day simulation was carried out during which a waste processor stopped operating during the fourth day and remained inoperative. The results indicated that while the upper control layer did not have to carry out rescheduling, there was a time lag on the lower control layer. However, the lower control layer responded to the new environment in time to restore proper control.