Fault-Tolerant Consensus Control for Multiagent Systems: An Encryption-Decryption Scheme

In this paper, the fault-tolerant consensus control problem is investigated for multi-agent systems with sensor faults. A first-order difference equation is utilized to describe the sensor fault, and an observer is designed to estimate the state and the fault simultaneously. For congestion mitigation and/or security enhancement purposes, the estimated state is first encrypted into a series of finite-level codewords by an encryption algorithm and then transmitted to other agents through a directed topology. After being received, the codewords are then decrypted by the corresponding decryption algorithm and subsequently utilized to design the consensus controller. By constructing a novel matrix norm along with its compatible vector norm, a necessary and sufficient condition is obtained for the existence of the controller. In the end, two simulation examples are given to demonstrate the validity of the results in this paper.