Stability and PID control of NCS with time-varying delay and data packet dropout

For networked control system (NCS) with time-varying delay and data packet dropout, four control strategies, which are state feedback proportional-integral-derivative (PID) control, dynamical state feedback PID control, output feedback PID control and dynamical output feedback PID control, are proposed. The problems of the model, stability and controller design are focused. The NCS with time-varying delay and data packet dropout based on four kinds of PID control methods are modeled as four asynchronous dynamical systems (ADSs) constrained by event rates. Furthermore, according to the theory of ADS, Lyapunov stability theory and linear matrix inequality method, the four semi-negative definite matrix conditions of exponential stability and PID controller design methods for the NCS with time-varying delay and packet dropout are presented. Finally, numerical examples show that the proposed exponential stability conditions and controller design methods are feasible.