Symbolic Design of Networked Control Systems with State Prediction

Abstract

SUMMARY In this paper, we consider a networked control system where bounded network delays and packet dropouts exist in the network. The physical plant is abstracted by a transition system whose states are quantized states of the plant measured by a sensor, and a control specification for the abstracted plant is given by a transition system when no network disturbance occurs. Then, we design a prediction-based controller that determines a control input by predicting a set of all feasible abstracted states at time when the actuator receives the delayed input. It is proved that the prediction-based controller suppresses effects of network delays and packet dropouts and that the controlled plant still achieves the specification in spite of the existence of network delays and packet dropouts. key words: networked control systems, symbolic control, approximate similarity relations, state prediction

Deadlock-Free Symbolic Smith Controllers Based on Prediction for Nondeterministic Systems

“…Recently, an approximate contractive alternating (bi)simulation relation (acASR) is introduced, which enforces robustness against abstraction errors, sporadic disturbances such as packet dropouts, and input errors [10]- [12]. The authors extended the acASR-based symbolic synthesis to partial observation and delayed systems [13]- [17]. These approaches are extended to networked control systems [18], [19] Especially, in [16], the authors proposed a framework of a symbolic Smith controller, which proves that the Smith method is applicable not only in the classical control but also in symbolic control.…”