Decentralized networked control of discrete-time systems with local networks

This paper considers discrete-time large-scale networked control systems with multiple local communication networks connecting sensors, controllers, and actuators. The local networks operate asynchronously and independently of each other in the presence of variable sampling intervals, transmission delays, and scheduling protocols (from sensors to controllers). The time-delay approach that was recently suggested to decentralized stabilization of large-scale networked systems in the continuous time is extended to H_∞ decentralized control in the discrete time. An appropriate Lyapunov-Krasovskii method is presented that leads to efficient LMI conditions for the exponential stability and l₂-gain analysis of the closed loop large-scale system. Differences from the continuous-time results are discussed. A numerical example of decentralized control of 2 coupled cart-pendulum systems illustrates the efficiency of the results.