Resilient input-to-state stable filter design for nonlinear time-delay systems.

•The issue of input-to-state stable filter design for nonlinear time-delay systems subject to bounded external disturbance input and gain variations is considered.•Novel analysis results on input-to-state stability for the filtering error systems are presented on the basis of the Lyapunov functional method.•Computationally tractable design strategies for the desired resilient input-to-state stable filters are developed via using several decoupling techniques.