Dynamic plant simulation tool for LSS optimization
- Paper number
IAC-08.A1.5.3
- Author
Mr. Alberto Torasso, Politecnico di Torino, Italy
- Coauthor
Mr. Markus Czupalla, Technical University of Munich, Germany
- Coauthor
Mr. Thomas G. Dirlich, Technische Universität München, Germany
- Coauthor
Mrs. Giorgia Cagliero, Politecnico di Torino, Italy
- Year
2008
- Abstract
In the design process for Life Support Systems (LSS) a great multitude of concepts and various combinations of subsystems and components exist. The often used ESM based trade study approach for life support systems is well suited for phase A conceptual design evaluations, but at same time is not able to provide system level characteristics such as stability, controllability and effectiveness. These parameters directly impact the scientific efficiency of the crew. Thus, for system level optimization these criteria must be included alongside the ESM in an integral optimization criterion. In order to be able to apply such an integral criterion, dynamic modeling of most involved LSS components (closed environment, crew, plant, P/C system) is necessary. In an effort to establish a dynamic simulation environment for habitats for extreme environmental conditions, the “Virtual Habitat” tool is being developed by the Human Spaceflight Group of the Technische Universität München (TUM). An important part of this tool is the plant model, which describes the dynamic behavior of plants in a closed environment. This paper is focused on the development of a dynamic plant model and its interactions with the spacecraft closed environment model. Plants play a fundamental role in advanced LSS concepts, thanks to their capacity to regenerate the atmosphere, producing oxygen necessary for humans and consuming carbon dioxide. In addition plants are capable of food production diversifying the astronauts’ diet. However, plants just as humans are living beings and such very sensitive to environmental changes, which can be very severe in a closed environment with very limited gas buffers. In order to be able to simulate the behavior of plants in a closed correctly, a highly dynamic plant model has been developed in a Matlab/Simulink environment based on the SUCROS wheat model. The developed model takes into account the effects of multiple environmental parameters on the plant development. The captured dependencies include influences such as light, temperature, atmosphere composition and partial pressures as well as the humidity levels in the atmosphere and in the ground. The model calculates plant growth and exchange of matter and energy with the environment, allowing a full dynamic feedback simulation. That is, not only the plant is affected by the environment but also the plant changes the surrounding environment. With such a dynamic model unique information about plant cultivation in an LSS can be derived. For example the amount of biomass in a plant growth chamber is calculated and informations are available about used up CO2 and produced O2 at any time during a plants lifetime. The model is developed with a special attention to wheat plants, but other edible plants such as tomatoes, potatoes and legumes are included. The paper describes the main characteristics of the plant model, and the results of simulation. In addition a dynamic closed environment module and the interaction with a dynamic human model are presented and discussed. Further the modularity strategy and interfaceability of the sub-models of the Virtual Habitat are discussed highlighting the resulting model limitations. Finally in the paper an outlook is given on the tasks remaining before the plant model and the Virtual Habitat can be used to optimize life support systems on a system level.
- Abstract document
- Manuscript document
IAC-08.A1.5.3.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.