Asymptotic Behavior of Networked Control Systems

The deening characteristic of a networked control system (NCS) is having a feedback loop that passes through a local area computer network. This paper considers nonlinear systems controlled in this manner, and demonstrates that for suuciently high transmission rates, the network may be considered transparent. Three methods of scheduling data packets are compared: a static scheduler (token ring), the Try-Once-Discard (maximum-error-rst) scheduler with continuous priority levels, and the Try-Once-Discard scheduler with discrete priority levels. The third method is of particular interest when only a small number of bits are available for collision resolution. Asymptotic stability is guaranteed in the rst two cases, and ultimate uniform boundedness in the third. In the nal section, simulations demonstrate the theoretical results. The contributions of this paper are twofold: rst, it extends the earlier results on NCS to nonlinear systems, and second, it allows for nite word-length message identiiers.