Ming Chi

Guaranteed performance consensus in second-order multi-agent systems with hybrid impulsive control

This paper studies the problem of guaranteed performance consensus in second-order multi-agent systems. Taking advantage of impulsive control, a hybrid cooperative control is presented, and an index function is introduced to assess the performance of agents. It is shown that by synthesizing the coupling weights and the average impulsive intermittence, multi-agent systems can achieve guaranteed performance consensus. A numerical example is given to illustrate the theoretical results.

Event-triggered control for networked control systems with quantization and packet losses

Abstract Problems of the quantized stabilization for event-triggered networked control systems (NCSs) with packet losses are addressed. To reduce the communication resources in NCSs, event-triggering scheme is adopted and designed. A NCS model is proposed which considers quantization, plant uncertainty, event-triggering scheme and packet losses simultaneously. Sufficient conditions for the stabilization and control design are derived using the Lyapunov functional approach and control synthesis of event-triggered networked control systems are established in terms of linear matrix inequalities. Moreover, the maximal allowable number of successive packet losses in NCS is estimated. A numerical example is given to illustrate the effectiveness of the proposed method.

Distributed tracking control of second-order multi-agent systems with sampled data

Abstract This paper studies the leader–follower consensus problem of second-order multi-agent dynamical systems with fixed and stochastic switching topologies in a sampled-data setting. A distributed linear consensus protocol is designed to track an active leader, where the current position information of neighbor agents and self-velocity data are utilized. A necessary and sufficient condition is established under fixed and directed topology for reaching consensus, which depends on the sampling period and control gain parameters. A sufficient condition is obtained under the Markov switching topology case. Finally, some numerical simulations are provided to verify the effectiveness of the theoretical results.

Multi-formation control of nonlinear leader-following multi-agent systems ☆

This paper deals with the multi-formation control problem for nonlinear leader-following multi-agent systems. Both the fixed topology case and the switching topology case are considered. The neighbor-based multi-formation control protocols are proposed under the assumption that for one subgroup, the total information received from other subgroups is zero. Then, based on the Lyapunov stability theory combined with the algebraic graph theory, sufficient conditions are established to ensure that the leader-following multi-agent systems with nonlinear dynamics can reach and maintain the desired multi-formation control. Finally, simulation examples are provided to illustrate the effectiveness of the theoretical results.

On consensus performance of nonlinear multi-agent systems with hybrid control

Abstract This paper focuses on the consensus performance of multi-agent systems with second-order nonlinear dynamics. In light of consensus performance, we resort to a hybrid impulsive and switching control scheme, an improved control updating rule is thus developed to ensure that agents realize consensus and meet some global performance guarantee simultaneously. With certain assumptions on the underlying topology and the nonlinearity of dynamics, it is shown that consensus can be achieved and consensus performance can be guaranteed under the proposed hybrid control scheme if the control time intermittence is properly restricted. Simulation work is presented to illuminate the obtained theoretical results.

Fractional-order consensus of multi-agent systems with event-triggered Control

In this paper, the event-driven control strategies have been proposed to study the consensus of fractional-order multi-agent systems. A general consensus control algorithm is introduced to analyze the fractional-order agent dynamics. Base on limited resources of embedded microprocessors and wireless sensors, event-triggered control mechanism have been exploited in a centralized approach, where all agents implement the same control update by the global measurement error. While in distributed counterpart, each agent executes control update depending on the information of itself and its neighboring agents. Sufficient conditions for consensus have been achieved on interaction graph and event-triggered real time constraint parameter. Finally, simulation examples are presented to illustrate the results.

Fundamental performance limitations of networked control systems with novel trade-off factors and constraint channels

Abstract This paper focuses on the optimal tracking performance issues for linear time invariant system with bandwidth limited and additive colored white Gaussian noise (ACGN) simultaneously. The nonminimal phase and unstable plant are considered, and multi-repeated zeros and poles is investigated. The objective function of tracking response is minimized jointly with the control effort. In order to more fully reflect the performance of the network control systems (NCSs), the performance index is measured by the tracking error energy, input channel energy and plant input energy using novel trade-off factors. The novel trade-off factors can be measured each frequency band for each signal, which are stable and minimal phase transfer function. To obtain the optimal performance, the two-parameter controller is adopted. The tracking performance is given by explicit expression, which is critically dependent on the intrinsic characteristics of the given plant (unstable poles and nonminimal phase zeros), communication parameters (bandwidth and statistical characteristics of network noise) and statistical characteristics of reference signal. Finally, the simulation results demonstrate the effectiveness of the proposed control scheme.

Bounded synchronization of coupled Kuramoto oscillators with phase lags via distributed impulsive control

Abstract In this paper, we study the synchronization of networked Kuramoto oscillators with phase lags. Distributed impulsive control strategies are developed to ensure the synchronization of coupled Kuramoto oscillators with phase lags. A sufficient condition is given to ensure bounded synchronization whose boundary can be sufficiently and arbitrary small. Especially, when oscillators are identical and phase lags are uniform, the exponential convergence criteria are derived. The proposed control strategies are valid for arbitrary distributions of phase lags with a boundary. Finally, numerical simulations are given to illustrate the effectiveness of the proposed control strategies.

Task-space coordinated tracking of multiple heterogeneous manipulators via controller-estimator approaches

Abstract This paper studies the task-space coordinated tracking of a time-varying leader for multiple heterogeneous manipulators (MHMs), containing redundant manipulators and nonredundant ones. Different from the traditional coordinated control, distributed controller-estimator algorithms (DCEA), which consist of local algorithms and networked algorithms, are developed for MHMs with parametric uncertainties and input disturbances. By invoking differential inclusions, nonsmooth analysis, and input-to-state stability, some conditions (including sufficient conditions, necessary and sufficient conditions) on the asymptotic stability of the task-space tracking errors and the subtask errors are developed. Simulation results are given to show the effectiveness of the presented DCEA.

Optimal tracking performance of control systems with two-channel constraints

This paper focuses on the tracking performance limitation for a class of networked control systems (NCSs) with two-channel constraints. In communication channels, we consider bandwidth, energy constraints and additive colored Gaussian noise (ACGN) simultaneously. In plant, non-minimal zeros and unstable poles are considered; multi-repeated zeros and poles are also applicable. To obtain the optimal performance, the two-parameter controller is adopted. The theoretical results show that the optimal tracking performance is influenced by the non-minimum phase zeros, unstable poles, gain at all frequencies of the given plant, and the reference input signal for NCSs. Moreover, the performance limitation is also affected by the limited bandwidth, additive colored Gaussian noise, and the corresponding multiples for the non-minimum phase zeros and unstable poles. Additionally, the channel minimal input power constraints are given under the condition ensuring the stability of the system and acquiring system performance limitation. Finally, simulation examples are given to illustrate the theoretical results.