Distributed consensus for multiple Euler-Lagrange systems: An event-triggered approach

IEEE Trans. Syst. Man Cybern, Syst.

Qin

et al. 2019

This paper proposes three different distributed event-triggered control algorithms to achieve leader-follower consensus for a network of Euler-Lagrange agents. We firstly propose two model-independent algorithms for a subclass of Euler-Lagrange agents without the vector of gravitational potential forces. By model-independent, we mean that each agent can execute its algorithm with no knowledge of the agent selfdynamics. A variable-gain algorithm is employed when the sensing graph is undirected; algorithm parameters are selected in a fully distributed manner with much greater flexibility compared to all previous work concerning event-triggered consensus problems. When the sensing graph is directed, a constant-gain algorithm is employed. The control gains must be centrally designed to exceed several lower bounding inequalities which require limited knowledge of bounds on the matrices describing the agent dynamics, bounds on network topology information and bounds on the initial conditions. When the Euler-Lagrange agents have dynamics which include the vector of gravitational potential forces, an adaptive algorithm is proposed which requires more information about the agent dynamics but can estimate uncertain agent parameters.For each algorithm, a trigger function is proposed to govern the event update times. At each event, the controller is updated, which ensures that the control input is piecewise constant and saves energy resources. We analyse each controllers and trigger function and exclude Zeno behaviour. Extensive simulations show 1) the advantages of our proposed trigger function as compared to those in existing literature, and 2) the effectiveness of our proposed controllers.

Section: A Contributions Of This Papermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Event-Triggered Algorithms for Leader–Follower Consensus of Networked Euler–Lagrange Agents

IEEE Trans. Syst. Man Cybern, Syst.

Qin

et al. 2019

“…Continuous communication will also cause the communication resource competing among agents. To remove the requirement for continuous communication and reduce the communication cost, researchers have begun to study the centralized/distributed event-triggered consensus problem [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. The event-triggered average-consensus problem was considered for MAS with single-integrator dynamics in [14].…”

Section: Introductionmentioning

confidence: 99%

Distributed event‐triggered feedback consensus control with state‐dependent threshold for general linear multi‐agent systems

Intl J Robust & Nonlinear

et al. 2016

This paper considers the distributed event-triggered consensus problem for multi-agent systems with general linear dynamics under undirected graphs. Based on state feedback, we propose a novel distributed eventtriggered consensus controller with state-dependent threshold for each agent to achieve consensus, without continuous communication in either controller update or triggering condition monitoring. Each agent only needs to monitor its own state continuously to determine if the event is triggered. It is proved that there is no Zeno behavior under the proposed consensus control algorithm. To relax the requirement of the state measurement of each agent, we further propose a novel distributed observer-based event-triggered consensus controller to solve the consensus problem in the case with output feedback and prove that there is no Zeno behavior exhibited. Finally, simulation results are given to illustrate the theoretical results. X. LIU ET AL. could only converge to a neighborhood around the origin, and the thresholds in [20], [21] are timedependent. In addition, the strict time-dependent nature of the triggering functions will decouple the network evolution from the actual states of the agents. Therefore, the state-dependent thresholds in event-triggered consensus strategy have been investigated. References [22] discussed the event-triggered consensus strategy with state-dependent thresholds and extended the results to a self-triggered setup. Under the assumption that all agents have initial access to a common parameter, [23] proposed an event-triggered broadcasting law with state-dependent triggering functions where agents do not rely on the availability of continuous information about their neighbors. In [24], a distributed event-triggered communication and control strategy with state-dependent thresholds that solved the multi-agent average consensus problem was proposed. However, both [22][23][24] focused on the single-integrator dynamics. The event-triggered consensus control strategy with state-dependent triggering functions for MAS with general linear dynamics was investigated in [25][26][27]. While, both [25][26][27] required continuous communication of neighbors' states to check the triggering conditions.It is well known that feedback control laws are typically implemented on digital platforms and executed periodically. The design of such controllers can be accomplished by using the welldeveloped theories and techniques on event-triggered control strategy. Because of these advantages, event-triggered feedback control of MAS has attracted more and more attention, see [14,15,22,25,30], just to name a few. It can be found from those works that most event-triggered controllers for MAS are single or double integrator and based on state-feedback under a restrictive assumption that all the agent states can be measured. Unfortunately, state measurement may not be available in real world. So, consensus control strategy based on state feedback should be replaced by using output feedback in those scenarios....

“…Over the past two decades, the distributed coordination of multi-agent systems has received significant attention in the control community due to its widely applications in various engineering systems such as data fusion of sensor networks, task cooperation of robots, synchronization of distributed oscillators, and formation maneuver of unmanned vehicles. As the most fundamental research topic for multi-agent systems coordination, consensus problem has been investigated intensively, and many remarkable contributions have been made [1][2][3][4][5][6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Sampled-data based consensus for multiple harmonic oscillators with directed switching topology

Journal of the Franklin Institute

Zhao

Shi

2017

Self Cite

This paper investigates the distributed consensus problem for a group of harmonic oscillators under directed switching topology. First, under the assumption that the union of the directed interaction graphs has a spanning tree, a class of sampleddata based consensus protocols are designed by using motion planning approaches and Pontryagin's principle. The proposed protocols only require that the union of communication topologies switched at the sampled instants has a spanning tree, without requiring information exchanges over the sampled interval and the connectivity of communication topology at each sampling instant. Then, the distributed consensus problem can be solved under directed switching topology by using stability principle and the properties of stochastic matrixes. Compared with the existing sampled-data based consensus algorithms, in this article, a remarkable advantage is that, for the proposed sampled-data based protocols, the sampled periods, communication topologies and control gains are decoupling and can be separately designed, which relaxes many restrictions in controller designs. Finally, as an extension of the leaderless consensus protocols, a leader-following consensus algorithm is further proposed in this paper. Some numerical examples are also given to illustrate the effectiveness of the analytical results.