Design of unknown input observer for a class of nonlinear systems

In the field of control, observing the nonlinear system state and unknown input have always occupied a very important position. A class of unknown input observer presented in this paper is using the nonsingular terminal sliding mode method which not only improves the accuracy of observer, but also can converges the error to zero in finite time. With the stronger robustness of the system, the sliding mode control signal can track the system state more accurately. Finally, there are the simulation results to verify the feasibility of this design.