A two dimensional bounded error observer for a class of bioreactor models

In this paper, we build bounded error observers for a common class of partially known bioreactor models in two dimensions. The main idea is to build bounded observers “between” the high gain observer, which has an adjustable rate of convergence but requires a perfect knowledge of the model, and an asymptotic observer which is very robust towards uncertainty but with a fixed rate of convergence. We build a two dimensional bounded error observer which reconstructs the two states variables with an error depending on the knowledge of the model; this error is as small as we want. Thus, we obtain better convergence rate for the estimate states than the asymptotic observer.