Leader-following fixed-time output feedback consensus for second-order multi-agent systems with input saturation

This paper studies fixed-time consensus of second-order leader-following multi-agent systems with inherent nonlinear dynamics. Firstly, a new fixed-time consensus protocol is designed to solve the tracking problem of the second-order nonlinear systems. By using Lyapunov theory and graph theory, we choose a different Lyapunov function candidate to verify the theoretical results. Then we consider the second-order multi-agent systems with multiple leaders and propose a new protocol to solve the fixed-time containment control problem. Finally, two numerical examples are proposed to demonstrate the effectiveness of the proposed fixed-time protocols.

Quantized consensus of second-order multi-agent systems via impulsive control

This study is devoted to investigating the fixed-time consensus disturbance rejection problem for a class of high-order nonlinear multi-agent systems (MASs) with input saturation. A distributed fixed-time state observer (FTSO) is first proposed to reconstruct the leader’s states for each follower. Based on the estimated values, a fixed-time consensus protocol is designed via backstepping, where a fixed-time disturbance observer (FTDO) is used to provide the robustness against the external disturbances. The violation of the input saturation is prevented by introducing an auxiliary variable and the problem of “explosion of terms” suffered by the conventional backstepping design is also successfully avoided by a fixed-time differentiator. Detailed convergence results are presented by leveraging Lyapunov stability theory. Finally, the effectiveness of the proposed approach is numerically validated through simulation results.

This letter focuses on the problem of leader-following consensus of second-order Multi-Agent Systems (MAS) with switching topology and partial aperiodic sampled data. MAS are subject to various constraints related to information exchange among the agents. It is considered that each agent in the network is able to measure its position only and cannot measure either its velocity or acceleration (input). Moreover, the position information is sent to the neighbors at aperiodic and asynchronous sampling rates. At last, a switching communication topology among the agents is considered. An observer-based control protocol is proposed to achieve leader-following consensus for MAS with above mentioned constraints. Using an Average Dwell Time (ADT) approach, sufficient conditions are derived through Lyapunov-based stability analysis to ensure the leader-following consensus. Numerical examples are also included to show the effectiveness of the proposed scheme.

This paper studies the finite-time consensus (FTC) of second-order multi-agent systems (MASs), where the event-triggered strategy is adopted. Firstly, a new protocol is designed to solve the FTC problem for the MASs under consideration. Then, by using Lyapunov theory and graph theory, the sufficient conditions are obtained to guarantee the FTC of the MASs. Meanwhile, a lower-bounded inter-event time is given to exclude the Zeno behavior. Finally, a numerical simulation is presented to demonstrated the effectiveness of the theoretical results.

Consensus of second-order multi-agent dynamic systems with quantized data

Consensus of second-order multi-agent systems under unknown but bounded measurement noises

Leader-following almost output consensus for discrete-time heterogeneous multi-agent systems in the presence of external disturbances

The speed coordinated control methods for multiple permanent magnet synchronous motors (multi-PMSMs) based on the consensus of multiagent systems (MASs) are proposed, which provide a new idea to achieve speed coordinated control of multimotors using artificial intelligence. First, the vector control system of individual motor is regarded as an agent, which can interact with its neighbors for information exchange based on the undirected communication network, and the speed coordinated control problem is transformed into the consensus control problem of MASs. A basic fixed-time consensus protocol (FTCP) is proposed and analyzed in this article. However, the limitation of FTCP lies in its non-smoothness, which makes the system prone to chattering problems. Therefore, a smooth improved fixed-time consensus protocol (IFTCP) is designed, which does not contain the sign function. Second, the supertwisting extended state observer is employed to estimate the disturbances in the system and perform feed-forward compensation into the consensus protocol, thereby obtaining the desired <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i>-axis current. Then, a fixed-time complementary sliding mode control current controller is designed to track the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i>-axis reference current. Finally, the two proposed methods are compared with the deviation coupling control method on the experimental platform to verify the effectiveness and feasibility. The experimental results show that both the FTCP and IFTCP methods exhibit excellent tracking performance and enhanced robustness, the IFTCP method can better suppress the chattering phenomenon of the system.

This paper discusses the leader-following consensus problem of second-order homogeneous multi-agents systems, in which it takes into consideration some different cases about the parameter in position difference and velocity difference. Firstly, we use the incidence matrix of the directed spanning tree to construct a linear transformation matrix, and the consensus problem is equivalently converted into the stability problem concerning input to the state.When there are no constraint on the control parameters, through Lyapunov stability and the linear matrix inequality, we can get better control parameters to make the system asymptotically reach the state consensus and ensure the convergence rate of the system. We analyzed three special cases and compared the previous results. We use the condition that the real part of the eigenvalue of matrix equivalent to A̅ is less than zero when the matrix is Hurwitz stable. This way can calculate a broader set of values of the control parameters more simply and clearly. Finally, numerical examples are presented to validate the theoretical results.

In this paper consensus in second-order multi-agent systems with a non-periodic sampled-data exchange among agents is investigated. The sampling is random with bounded inter-sampling intervals. It is assumed that each agent has exact knowledge of its own state at all times. The considered local interaction rule is PD-type. The characterization of the convergence properties exploits a Lyapunov-Krasovskii functional method, sufficient conditions for stability of the consensus protocol to a time-invariant value are derived. Numerical simulations are presented to corroborate the theoretical results.

In this paper, fast stationary and dynamic consensus protocols are proposed for multi-agent systems (MASs) with undirected fixed topologies by predicting the state information in the past. The system stability is analyzed from the frequency domain analysis by virtue of algebraic theory. It is proved that the MAS using past-state prediction reaches consensus faster than its counterpart merely using current state information when the multi-agents’ past state information value and prediction strength value are properly selected. The necessary and sufficient conditions on the stability of MASs and the sufficient conditions on MASs’ convergence speed are established. Finally, the effectiveness of the proposed consensus protocol is verified through numerical simulations.KeywordsMulti-agent systemsConsensusConvergence speedPrediction

Leader-following secure consensus for second-order multi-agent systems with nonlinear dynamics and event-triggered control strategy under DoS attack

Distributed impulsive consensus of nonlinear multi-agent systems with input saturation

Fixed-time consensus for multi-agent systems with objective optimization on directed detail-balanced networks