Design of Nonlinear Unknown Input Observers and Its Application in Automobile Airbag Production Line

Aiming at the state estimation problem of a class of nonlinear systems, a method of Unknown Input Observers which complies with a robust sliding mode control law and an adaptation law is designed in this paper considering that the time delay that may lead to the instability of the system performance is inevitable in the process of modern networked control. Then the convergence of the designed observer is verified by Lyapunov stability criterion. Finally, the observer is applied to realize the estimation of the roll diameter and tension of the bagging station of the automobile airbag production line. The experimental results verify the effectiveness of the proposed scheme.