Hierarchically controlled ecological life support systems.

• Designing a hierarchical control structure to control the long-term operation of life support systems. • Efficient response to varying operating conditions by using hierarchically distributed control functions. • Coordinating a network of biological compartments with a variety of generation, consumption, and storage capabilities. • Control of O 2 concentration in the crew compartment, as the main consumer of a life support system. Life support systems (LSSs) are autonomous systems integrating various generation, recycling, and consumption subsystems with storage capability to maintain the balance of key system compounds. A novel hierarchical control is proposed in this paper to operate an exemplary controlled ecological LSS. The study focuses on the control of O 2 concentration in the crew compartment, as the main consumer of a LSS, while coordinating a network of biological compartments with a variety of generation, consumption, and storage capabilities. A concentrated gas buffer tank is included in the system to demonstrate its capability to support the system operation flexibility and efficiency. Simulation analyses for changing O 2 demand scenarios are carried to assess the proposed control architecture performance. [Display omitted] [ABSTRACT FROM AUTHOR]