Robust consensus of linear systems on directed graph with non‐uniform delay

The authors propose a consensus control framework for multiple heterogeneous general single‐input single‐output linear systems with no zeros at s = 0 on a directed information graph with constant, yet, non‐uniform and unknown delays. The proposed consensus control is easy to design via loop‐shaping like graphical approach, robust against plant uncertainty and constant delay, and completely decentralisable (i.e. locally synthesisable without consulting other agents). Consensus proof using multi‐input multi‐output Nyquist theorem and algebraic graph theory is given, with a numerical example to illustrate the theory.