This article studies the distributed fault-tolerant bipartite output synchronization problem of discrete-time linear multiagent systems (MASs) with process faults under a general directed signed graph. The reference signal is generated by an autonomous exosystem, which can also be seen as a leader. All followers are divided into two subgroups with antagonistic interactions, and the followers in each subgroup are cooperative. We aim to solve the bipartite fault-tolerant control (FTC) problem via the output regulation theory such that bipartite output synchronization can be achieved in the presence of process faults, that is, the outputs of followers with different subgroups can approach the output of exosystem with the same magnitude and the opposite sign regardless of process faults. To estimate the states and the faults of each follower, a simultaneous state and fault estimator based on the neighboring signed output estimation error and the standard discrete-time algebraic Riccati equation (ARE) is designed. Besides, a new exosystem observer with two classes of convergence conditions relying on the respective solutions of standard and modified AREs is provided. All eigenvalues of the exosystem matrix can lie completely outside the unit circle. Based on these estimations, we present a distributed fault-tolerant output feedback controller, which can overcome the no-loops constraint. Finally, simulation results are given to demonstrate the analytic results.

This paper studies the problem of cooperative fault-tolerant output regulation of leader-follower multi-agent systems with sensor faults. To compensate for the faults existing in the followers, distributed observers based on relative output estimation errors are firstly designed. Then an adaptive fault-tolerant output regulation framework is built by solving the regulator equation. It is shown that stability of the closed-loop system can be ensured and that all tracking errors will converge to zero under the designed fault-tolerant controller. Finally, simulation results demonstrate the effectiveness of the proposed control law.

This paper studies the distributed bipartite output formation control problem of heterogeneous discrete-time linear multi-agent systems (MASs) via cooperative output regulation theory. To construct the bipartite formation, under the structurally-balanced augmented directed signed graph, the followers of two antagonistic subgroups are supposed to respectively keep the desired relative positions with the leader, also called as the exosystem, in the same magnitude but the opposite sign. Since the information of exosystem can not be directly obtained by all followers, the distributed exosystem observer based on the discrete-time algebraic Riccati equality (ARE) is presented and the distributed state feedback controller is further designed. Moreover, consider the case where the states of followers are not available, the distributed output feedback controller is proposed by introducing the state estimator. Finally, two numerical examples are given to demonstrate the effectiveness of analytic results.