Further results on delay robustness of interconnected passive systems

We analyze the stability of networks of passive systems with time delays in the interconnections. Building upon previous work where we complemented the passivity property with a “roll-off” integral quadratic constraint (IQC), here we expand our results to state space models. We first demonstrate how to verify that a state space model satisfies passivity and roll-off IQCs when the equilibrium is not known. We then illustrate the result on an Internet congestion control problem.