Leader-following Coordination Research Articles

Event-Triggered Reference Governors for Collisions-Free Leader–Following Coordination Under Unreliable Communication Topologies

Event-Triggered Reference Governors for Collisions-Free Leader–Following Coordination Under Unreliable Communication Topologies

PDE-based leader-following coordination control for flexible manipulators with event-triggered communication over directed graphs

PDE-based leader-following coordination control for flexible manipulators with event-triggered communication over directed graphs

Leader-Following Multi-Agent Coordination Control Accompanied With Hierarchical Q(λ)-Learning for Pursuit

In this paper, we investigate a pursuit problem with multi-pursuer and single evader in a two-dimensional grid space with obstacles. Taking a different approach to previous studies, this paper aims to address a pursuit problem in which only some pursuers can directly access the evader’s position. It also proposes using a hierarchical Q(λ)-learning with improved reward, with simulation results indicating that the proposed method outperforms Q-learning.

Consensus tracking control for sampled-data second-order multi-agent systems with arbitrary weights under fixed communication topology

This paper focuses on the consensus tracking control problem of multi-agent systems (MASs) with arbitrary adjacency weights instead of traditional nonnegative weights in a sampling setting. First, unlike Lemma 4 in Hu and Hong [2007. Leader-following coordination of MASs with coupling time delays. Physica A: Statistical Mechanics and its Applications, 374(2), 853–863], for MASs with arbitrary weights, the global reachability of the leader node is just a necessary but not a necessary and sufficient condition to guarantee the positive stability of matrix H. Hence, it's urgent for us to establish some positive stability criteria of matrix H first, which is a necessary condition for MASs to achieve consensus tracking. Simultaneously, we also solve the following problems successfully: which nodes should have direct connection with the leader? What's the range size of the leader adjacency coefficients? Then, some sufficient consensus tracking control conditions are obtained for MASs without time-delays and with time-delays by using matrix analysis method and perturbation theory, respectively. Finally, numerical examples are given to illustrate the effectiveness of our results.

Semi-global leader-following coordination of multi-agent systems with input saturation and aperiodic intermittent communications

This paper addresses the semi-global leader-following coordination problem of general linear multi-agent systems, in which the control input of each agent is steered by aperiodically intermittent saturated actuator. Both the case with only one virtual leader and the case with multiple virtual leaders are discussed. By using multiple Lyapunov stability theory and applying algebraic Riccati equation-based low-gain feedback technique, sufficient conditions guaranteeing semi-global consensus tracking and semi-global containment tracking are provided. Numerical simulations finally verify the theoretical analysis.

Distributed coordination for a class of non‐linear multi‐agent systems with regulation constraints

In this paper, a multi-agent coordination problem with steady-state regulation constraints is investigated for a class of nonlinear systems. Unlike existing leader-following coordination formulations, the reference signal is not given by a dynamic autonomous leader but determined as the optimal solution of a distributed optimization problem. Furthermore, we consider a global constraint having noisy data observations for the optimization problem, which implies that reference signal is not trivially available with existing optimization algorithms. To handle those challenges, we present a passivity-based analysis and design approach by using only local objective function, local data observation and exchanged information from their neighbors. The proposed distributed algorithms are shown to achieve the optimal steady-state regulation by rejecting the unknown observation disturbances for passive nonlinear agents, which are persuasive in various practical problems. Applications and simulation examples are then given to verify the effectiveness of our design.

Leader-following coordination of multiple UUVs formation under two independent topologies and time-varying delays

The new method which uses the consensus algorithm to solve the coordinate control problems of multiple unmanned underwater vehicles (multi-UUVs) formation in the case of leader-following is adapted. As the communication between the UUVs is difficult and it is easy to be interfered under the water, time delay is assumed to be time-varying during the members communicate with each other. Meanwhile, the state feedback linearization method is used to transfer the nonlinear and coupling model of UUV into double-integrator dynamic. With this simplified double-integrator math model, the UUV formation coordinate control is regarded as consensus problem with time-varying communication delays. In addition, the position and velocity topologies are adapted to reduce the data volume in each data packet which is sent between members in formation. With two independent topologies designed, two cases of communication delay which are same and different are considered and the sufficient conditions are proposed and analyzed. The stability of the multi-UUVs formation is proven by using Lyapunov-Razumikhin theorem. Finally, the simulation results are presented to confirm and illustrate the theoretical results.

Coordination of multi-agent systems under switching topologies via disturbance observer-based approach

ABSTRACTIn this paper, a leader-following coordination problem of heterogeneous multi-agent systems is considered under switching topologies where each agent is subject to some local (unbounded) disturbances. While these unknown disturbances may disrupt the performance of agents, a disturbance observer-based approach is employed to estimate and reject them. Varying communication topologies are also taken into consideration, and their byproduct difficulties are overcome by using common Lyapunov function techniques. According to the available information in difference cases, two disturbance observer-based protocols are proposed to solve this problem. Their effectiveness is verified by simulations.

Leader‐following coordination problem with an uncertain leader in a multi‐agent system

A leader-following coordination problem is considered in this study where the active leader is driven by an unknown input. With the help of output regulation and disturbance decoupling, a distributed protocol is proposed to solve this problem. Two cases are studied based on whether the bound of uncertain (disturbance) inputs of the leader is known. When the bound is unknown, an adaptive technique is employed to achieve the goal. Simulations are also given to verify the effectiveness of these controllers.

Adjacent-Compensation Consensus Algorithm in Asynchronously Coupled Form for Second-Order Multiagent Network under Communication Delay

General asynchronously coupled consensus algorithm associated with adjacent compensations, is proposed to solve the dynamical consensus problem of second-order multiagent network with communication delay under leader-following coordination control framework. Based on frequency-domain analysis, firstly, delay-independent consensus convergence is proved for the second-order multiagent systems with a spanning tree topology that has the leader root and then delay-dependent consensus condition is obtained for the multiagent systems with communication delay under a general leader-following interconnection topology. Simulation illustrates the correctness of the results.

Distributed H<sub>∞</sub> Control for Leader-Following Coordination with Switching Topology

In this paper, we consider multi-agent H∞consensus control problems with external disturbance under the undirected switching topologies. The agent dynamics is expressed in the form of a second-order model and the control laws are neighbor-based feedback laws. By using the model transformation, the multi-agent H∞consensus control problem is converted into H∞ control problem for a switching linear system with special structure. A sufficient condition is established under which all agents can reach consensus with the desired H∞performance in switching topology case by constructing a parameter-dependent common Lyapunov function. Moreover, we give an explicit estimation expression to estimate H∞ performance index. Finally, a numerical example is provided to illustrate the effectiveness of our results.

The L2-LInfinite Control for Leader-following Coordination with Switching Topology and Time-delay

In this paper, we investigate the L_2 - L_\infinity leader-following coordination problems with undirected switching topologies and external disturbance in two cases of the time delay and non-delayed networks. The agent dynamics is expressed in the form of a second-order model and the control laws are neighbor-based feedback laws. We first establish LMI sufficient conditions to guarantee that all following agents can track the leader agent with zero and nonzero communication delays respectively. Furthermore, we get a explicit estimation expression of L_2 - L_\infinity disturbance attenuation by constructing a parameter-dependent common Lyapunov function in case that there is no delay time. Finally, numerical examples are provided to illustrate the effectiveness of our results.

L2—L∞ control for leader-following coordination of second-order multi-agent systems

This paper deals with L2—L∞ control for leader-following coordination of second-order multi-agent systems with external disturbance and time-delay on fixed topology. In practical applications, the peak value of the controlled output is often required to be within a certain range and the ranges of the position and the velocity are different, so we introduce the weighted coefficients for the controlled outputs of the position and the velocity separately. Then, we obtain a multi-agent system of the model.Based on the Lyapunov-Krasovskii theory, both networks with and without time-delay are analyzed for leader-following corrdination of the position vector and the velocity vector with the desired L2—L∞ performance. Furthermore, sufficient conditions in terms of bilinear matrix inequality are given to guarantee the consensus problems for the multi-agent systems with and without time-delay sparately. Finally,numerical simulations are provided to show the effectiveness of our strategies.

Leader-following coordination of multi-agent systems with coupling time delays

In this paper, we consider a leader-following consensus problem of a group of autonomous agents with time-varying coupling delays. Two different cases of coupling topologies are investigated. At first, a necessary and sufficient condition is proved in the case when the interconnection topology is fixed and directed. Then a sufficient condition is proposed in the case when the coupling topology is switched and balanced. Numerical examples are also given to illustrate our results.