On-Line State Estimation of Microalgal Photobioreactors

Abstract

Photobioreactors are indispensable technical systems to cultivate photoautotrophic microorganisms. Sensing and control of photobioreactors are an essential and integral part of photobioreactor technology. The requirements of low instrumentation cost and multiple parameter on-line sensing call for innovative approach to address the sensing problems of photobioreactors. In this research, we apply on-line estimation methodology to photobioreactor systems. Two types of on-line estimators were developed and tested, using the extended Kalman filter as the optimizing algorithm. One was based the measurement of the dissolved oxygen level, and the other was based on the measurement of local irradiance level. Both estimators were proved to be able to track major cultural states, and detailed development of system models, implementation of the estimators, and the tuning of the parameters involving in the extended Kalman filters were reported in this thesis.