Robust Finite-time Consensus Research Articles

Robust Finite-Time Consensus of Coupled Markovian Logical Dynamic Networks

Robust Finite-Time Consensus of Coupled Markovian Logical Dynamic Networks

Robust finite-time consensus control for Euler–Lagrange multi-agent systems subject to switching topologies and uncertainties

Euler–Lagrange (EL) system is a typical nonlinear system widely used to model robot systems. Although consensus of EL multi-agent systems has been extensively studied in recent years, how to achieve better consensus performance under constraints such as switching topologies and uncertainties is still an open issue. Aiming at fast convergence and effective disturbance rejection, this paper studies the integral sliding mode control problem for robust finite-time consensus of EL multi-agent systems subject to switching topologies and uncertainties. A basic integral sliding mode control (SMC) scheme is first presented for finite-time consensus of EL multi-agent systems subject to undirected topologies and uncertainties. It is shown that the proposed consensus protocol reaches good disturbance rejection and achieves robust finite-time consensus while avoiding the singularity problem in the existing studies. The proposed integral sliding mode control scheme is further extended to finite-time consensus of EL multi-agent systems subject to directed and switching topologies. Compared with the existing algorithms, faster finite-time convergence is achieved. In the simulation studies, the obtained results demonstrate the effectiveness and efficiency of the proposed algorithm.

Robust finite-time consensus subject to unknown communication time delays based on delay-dependent criteria

In this paper, robust finite-time consensus of a group of nonlinear multi-agent systems in the presence of communication time delays is considered. In particular, appropriate delay-dependent strategies which are less conservative are suggested. Sufficient conditions for finite-time consensus in the presence of deterministic and stochastic disturbances are presented. The communication delays don’t need to be time invariant, uniform, symmetric, or even known. The only required condition is that all delays satisfy a known upper bound. The consensus algorithm is appropriate for agents with partial access to neighbor agents’ signals. The Lyapunov–Razumikhin theorem for finite-time convergence is used to prove the results. Simulation results on a group of mobile robot manipulators as the agents of the system are presented.

Distributed event-triggered adaptive finite-time consensus control for second-order multi-agent systems with connectivity preservation

In this paper, we consider the robust finite-time consensus problem for second-order multi-agent systems (MASs) with limited sensing range and weak communication ability. As a stepping stone, a novel distributed finite-time sliding mode manifold is developed for MASs. Then, by combining artificial potential function technique with the presented sliding mode manifold, a robust distributed control scheme is proposed to enable the finite-time consensus of MASs while preserving the prescribed communication connectivity. Furthermore, the sampling frequency and implementation burden of the proposed controller can be reduced with resort to the event-triggered methodology. Finally, numerical examples are given to show the effectiveness of the proposed method.

Distributed input observer-based finite-time consensus for the leader-following multi-agent systems

This paper mainly studies the problem of robust finite-time consensus for leader-following multi-agent systems in detail-balanced graphs. It is evident that the knowledge of the leader’s input will provide significant assistance to a follower in tracking the leader. For this reason, an observer is constructed to estimate the input of the leader for each follower. Compared with many existing works of leader-following consensus, we do not assume that the input of the leader is bounded, but assume instead that its derivative is bounded. Based on input observer, two discontinuous protocols are proposed firstly that require only the sign information of the differences between a given agent’s state and that of its neighbors. Then, the finite-time consensus and the upper-bound of the settling time are obtained by using matrix theory, Lyapunov control approach, and the algebraic graph theory. Finally, the availability of the theoretical results is demonstrated through an example.

Robust finite-time consensus control for multi-agent systems with disturbances and unknown velocities

In this paper, we investigated the finite-time consensus tracking problem for multi-agent systems with external bounded disturbances and input bounded disturbances and unknown velocities. Based on the Lyapunov finite-time theorem, a novel finite-time consensus control is constructed by using the backstepping method. For unknown velocities, the high-gain observer is used to estimate the velocity information. It is proved that the consensus can be achieved in finite time. The consensus shows fast response and strong robustness to various disturbances. Finally, the effectiveness of the results is illustrated by numerical simulations.

Robust finite-time connectivity preserving coordination of second-order multi-agent systems

In this paper, we consider robust finite-time connectivity preserving coordination problems for second-order multi-agent systems with limited sensing range. Based on integral sliding mode control and artificial potential field, a distributed controller is developed to achieve robust finite-time consensus and meanwhile maintain the connectivity of the communication network. The method is further extended to address a finite-time formation tracking control problem. Numerical examples are given to show the effectiveness of the proposed methods.

Robust finite-time consensus tracking for second-order multi-agent systems with input saturation under general directed communication graphs

ABSTRACTIn this paper, we study the global finite-time consensus tracking problem for uncertain second-order multi-agent systems subject to input saturation. The communication graphs are allowed to be general directed graphs. Sliding-mode observer-based distributed controllers are proposed such that global finite-time consensus tracking is achieved with bounded control inputs. Only relative state or output measurements are used in the proposed controller which reduces the communication requirement on the agents. Simulation examples are given to illustrate the effectiveness of the proposed control strategies.

Distributed robust finite-time nonlinear consensus protocols for multi-agent systems

This paper investigates the robust finite-time consensus problem of multi-agent systems in networks with undirected topology. Global nonlinear consensus protocols augmented with a variable structure are constructed with the aid of Lyapunov functions for each single-integrator agent dynamics in the presence of external disturbances. In particular, it is shown that the finite settling time of the proposed general framework for robust consensus design is upper bounded for any initial condition. This makes it possible for network consensus problems to design and estimate the convergence time offline for a multi-agent team with a given undirected information flow. Finally, simulation results are presented to demonstrate the performance and effectiveness of our finite-time protocols.

Leader-following finite-time consensus in second-order multi-agent networks with nonlinear dynamics

Robust finite-time consensus problems in leader-following multi-agent directed networks with second-order nonlinear dynamics are considered in this paper. By using matrix theory, algebraic graph theory and finite-time control scheme, a class of continuous distributed control algorithms are designed in a quite unified way for each follower agent to reach consensus in a finite time. A numerical example is also employed to illustrate the effectiveness and correctness of our theoretical results.