Robust control of interconnected network schemes subject to random time-varying communication delays

Owing to data transmissions and controller processing, in addition to the inherent plant delays, there are always network delays in a network-based control loop. It has been known that time delays not only degrade the system performance but also destabilize the controlled system. This paper proposes a new control structure, which consists of a remote predictive controller located at the master command station. The remote prediction is supported by a neural net-based Smith predictor that provides prediction and maintains the loop stability. A novel condition is derived, which ensures the loop stability of the networked control system while there are uncertain time delays. Numerical experiments show that the proposed control scheme is able to ensure stability and performance robustness of networked control systems.