“…Before giving the main results, we give necessary lemmas, assumptions, and definitions as follows: Lemma 1 In the linear system ( A,B,C ), if the pair ( A,B ) is stabilisable and the pair ( C,A ) is observable [7], then there exists a unique solution to the following algebraic Riccati equation: Assumption 1 The information exchanging graph G among agents in the system consisting of (1) and (2) is connected. Assumption 2 ( A,B ) is stabilisable and are system matrices. Remark 1 Assumptions 1 and 2 are standard in solving the leader–follower consensus problem in multi‐agent systems, such as [15, 29, 33], and so on. Definition 1 The system composed of (1) and (2) is said to get leader‐following consensus [29], if there exists control input so that for any initial conditions the closed‐loop system composed of (1), (2), and satisfies …”