Connectivity-Preserving Consensus of Heterogeneous Multiple Euler–Lagrange Systems With Input Saturation

This article investigates the consensus problem of multiple heterogeneous uncertain Euler–Lagrange systems with limited communication range and input saturation. Due to the heterogeneity of the system, it is difficult to directly design a protocol to achieve consensus. To deal with it, a virtual system framework is proposed such that the consensus problem can be decoupled into two simpler subproblems: consensus among virtual systems and tracking of virtual states by actual agents. Since two agents will lose connection when their distance is greater than limited communication range, large control inputs are required to maintain topological connectivity. However, in practical applications, the existence of input saturation constraints may cause insufficient torque generation and potential connectivity loss. To address this issue, virtual system interaction protection rules are further proposed. The requirements on the connectivity maintenance can be relaxed by allowing temporary disconnections between agents. Finally, a numerical example is provided to verify the effectiveness of the proposed protocol.