Distributed leader following of an active leader for linear heterogeneous multiagent systems Abstract   This paper considers a leaderfollowing problem for a group of heterogeneous linear time invariant (LTI) followers that are interacting over a directed acyclic graph. Only a subset of the followers has access to the state of the leader in specific sampling times. The dynamics of the leader that generates its sampled states is unknown to the followers. For interaction topologies in which the leader is a global sink in the graph, we propose a distributed algorithm that allows the followers to arrive at the sampled state of the leader by the time the next sample arrives. Our algorithm is a practical solution for a leaderfollowing problem when there is no information available about the state of the leader except its instantaneous value at the sampling times. Our algorithm also allows the followers to track the sampled state of the leader with a locally chosen offset that can be timevarying. When the followers are mobile agents whose state or part of their state is their position vector, the offset mechanism can be used to enable the followers to form a transnational invariant formation about the sampled state of the leader. We prove that the control input of the followers to take them from one sampled state to the next one is minimum energy. We also show in case of the homogeneous followers, after the first sampling epoch the states and inputs of all the followers are synchronized with each other. Numerical examples demonstrate our results.

Leaderfollowing consensus of linear timevarying multiagent systems under fixed and switching topologies Abstract   The leaderfollowing consensus problems for linear timevarying multiagent systems under fixed and switching topologies are considered. Several results are derived on the basis of Lyapunovxe2x80x99s direct method. For a network of linear timevarying agents with fixed topology, we provide two protocols, respectively. One of them uses global information of the communication topology. It guarantees the multiagent system to go to the leaderfollowing agreement with an arbitrarily given exponential rate. The other uses local information associated with each follower, and is implemented in a fully distributed fashion. It has robustness with respect to a certain degree of link failure. It is extended to a network of linear timevarying agents with switching topology. The resulting protocol guarantees the multiagent system to achieve the leaderfollowing consensus, if the union of switching graphs has a spanning tree rooted at the leader. It also has robustness with respect to a certain degree of link failure. Simulation examples are provided to validate the effectiveness of the results.