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

In this article, the fault-tolerant consensus control problem is investigated for multiagent 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 security enhancement and/or congestion mitigation 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, we obtain a necessary and sufficient condition, which serves as an index in the observer and the controller design. In the end, a simulation example is given to demonstrate the validity of the results in this article.