Contraction theory based observer for a biochemical process

This contribution reports the design of state estimator for a nonlinear process using the recently proposed contraction analysis approach. Although the contraction based stability analysis for nonlinear systems is now an accepted tool for analyzing control systems with uncertain parameters, application of this technique for designing nonlinear state estimator is fairly recent and still evolving. The contraction analysis based estimator design method is briefly outlined before applying the method for a biochemical process, for which existing literature indicates the use of traditional nonlinear observers. A comparative study of estimator performance between an extended Luenberger observer based state estimation and the contraction observer has been reported. Results of simulation show that state estimation using contraction observer is better than that of the classical one.