Event-triggering stabilization of real and complex linear systems with disturbances over digital channels

In the same way that subsequent pauses in spoken language are used to convey information, it is also possible to transmit information in communication systems not only by message content but also with its timing. In this work, we consider an event-triggering strategy that exploits timing information by transmitting in a state-dependent fashion. We consider stabilization of a continuous-time, time-invariant, linear system over a digital communication channel with bounded delay and in the presence of bounded system disturbance. For small values of the delay, we show that exploiting timing information one can stabilize the system with any positive transmission rate. However, for delay values larger than a critical threshold, the timing information is not enough for stabilization and the sensor needs to increase the transmission rate. Compared to previous work, our results provide a novel necessary condition for scalar system subject to disturbances and a novel encoding-decoding scheme for complex systems, which can be readily applied to diagonalizable multivariate system with complex eigenvalues. Our results are illustrated in numerical simulation of several scenarios.