Introducing jitter buffers in networked control systems with communication disturbance observer under time-varying communication delays

This paper proposes a time-delay compensation method applicable to networked control systems (NCSs) under time-varying communication delays. The communication disturbance observer (CDOB) is one of the effective time-delay compensation methods using the concept of network disturbance (ND). However, the ND cannot be compensated sufficiently when the communication time delays are dynamically varying as in the Internet because of their nonlinear nature. The proposed time-delay compensation method combining the CDOB and a jitter buffer technique, effectively improves the performance of the NCSs under time-varying communication delays. Simulations using a networked motion control system are performed to confirm the effectiveness of the proposed method. The simulation results show that the proposed method provides better performance than a conventional method.