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In this paper, we report on the development of an intelligent system for air quality monitoring and early detection and diagnosis of air contaminants. Optimal identification of contaminants is based upon the use of an Implicit Kalman Filter that uses both experimental data and a theoretical model to obtain optimal estimates. We have developed a three-dimensional unsteady-state model of contaminant transport, which uses a flow field generated numerically for the cabin using a finite element mesh. The optimal contaminant estimates are used as the basis for the detection of a contamination event. The algorithm is shown to distinguish between sensor faults and process faults.

In this paper we report on the development of the air quality monitoring and early detection system for an enclosed environment with specific emphasis on manned spacecraft. The proposed monitoring approach is based on the distributed parameter model of contaminant dispersion and real-time contaminant concentration measurements. The Implicit Kalman Filtering (IKF) algorithm is used to generate on-line estimations of the spatial contamination profile, which are used for the air quality monitoring and early detection of an air contamination event. We also solve the problem of the pointwise source identification of the convection-diffusion transport processes. This is done by converting the identification problem into an optimization problem of finding a spatial location and the capacity of a point source which results in the best match of the model-predicted measurements to the observed measurements.

An event in which electronic insulation consisting of polytetrafluoroethylene undergoes thermodegradation on the Space Station Freedom is considered experimentally and theoretically from the initial chemistry and convective transport through pulmonary deposition in humans. The low-gravity environment impacts various stages of event simulation. Vapor-phase and particulate thermodegradation products were considered as potential spacecraft contaminants. A potential pathway for the production of ultrafine particles was identified. Different approaches to the simulation and prediction of contaminant transport were studied and used to predict the distribution of generic vapor-phase products in a Space Station model.