Nonlinear unknown input observer design by LMI for lipschitz nonlinear systems

The paper is proposed the design method of nonlinear unknown input observer for Lipschitz nonlinear uncertain. Combined with the stability theory of nonlinear observers and LMI, LMI existence condition and some verification are given for the the nonlinear unknown input observers which can not only estimate the system´s state approximately, but enhance the robustness for the system unknown disturbance and nonlinearity as well. The unknown observers designing matrixes are computed using MATLAB LMI toolbox to make the difficult nonlinear observer design problem an easy task, and the designing freedoms are released. Numerical simulation results are presented to validate the approach.