On Networked Control Architectures for MIMO Plants

In this work we focus on control of MIMO LTI plants and explore the potential benefits of replacing a traditional diagonal non-networked control architecture with a networked full MIMO one. Diagonal terms of the networked MIMO architecture employ transparent links, whereas the off-diagonal terms use communication channels which are subject to signal-to-noise ratio constraints. Within this setup, we show how to design LTI coding systems which optimize overall performance. Unsurprisingly, for high-quality channels the full MIMO architecture is preferable to decentralized architectures. However, our analysis reveals that the achievable performance in the networked situation may become arbitrarily poor, if the signal-to-noise ratio constraints in the communication links are sufficiently severe. In these cases, traditional decentralized controller structures are preferable. In the present work, we limit our analysis to the two-input two-output case and illustrate our results for networked control systems with bit-rate limited communication channels.

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