Design of distributed controllers and communication topologies considering link failures

This paper presents results on optimization based design of distributed control laws for linear discrete-time systems interconnected through states, inputs, and a cost function. In the proposed scheme the subsystems may communicate state information, resulting in a trade-off between good closed-loop performance and high communication costs as well as robustness issues if communication links are unreliable. Previous results on optimization based synthesis of a communication topology and associated distributed control laws are extended to the case that (i) some communication links are prone to failure and that (ii) a controller may reconfigure itself, if it is directly affected by a link failure. To include this scenario into the synthesis problem, a link failure is modeled as a change in the network topology and of the affected controllers. The problem is formulated as a mixed-integer semi-definite problem (MISDP) which combines the discrete optimization of the network topology subject to communication constraints and link failures with subproblems for structured controller synthesis.