This paper investigates the average-consensus problem of multi-agent systems with direct and weighted topologies. Event-triggered control laws are adopted so as to reduce the frequency of individual control updating s...This paper investigates the average-consensus problem of multi-agent systems with direct and weighted topologies. Event-triggered control laws are adopted so as to reduce the frequency of individual control updating since the agents may be resource-limited in many real systems. The discrete time instants where the events are triggered are determined by a trigger function with respect to a certain measurement error. A centralized average-consensus protocol is proposed first for networks with fixed interaction topology, the stability and influencing factors of which are also analyzed. The design of trigger functions for networks with variable topology is also discussed. Then the results are extended to the decentralized counterpart, in which agents require only the information of their neighbors. Numerical examples are also provided that demonstrate the effectiveness of the theoretical results.展开更多
A new class of hybrid impulsive and switching models are introduced and their robust exponential stability and control synthesis are addressed. The proposed switched system is composed of stable subsystems and unstabl...A new class of hybrid impulsive and switching models are introduced and their robust exponential stability and control synthesis are addressed. The proposed switched system is composed of stable subsystems and unstable subsystems, which not only involves state delay and norm-bounded time-varying parameter uncertainties, but also contains the impulsive switching effects between the subsystems. Based on the extension of the system dimension and the concept of average dwell time, a kind of practically useful switching rule is presented which guarantees the desired robust exponential stability. A switched state feedback controller is also given.展开更多
This paper studies the weighted average consensus problem for networks of agents with fixed directed asymmetric unbalance information exchange topology. We suppose that the classical distributed consensus protocol is ...This paper studies the weighted average consensus problem for networks of agents with fixed directed asymmetric unbalance information exchange topology. We suppose that the classical distributed consensus protocol is destroyed by diverse time-delays which include communication time-delay and self time-delay. Based on the generalized Nyquist stability criterion and the Gerschgorin disk theorem, some sufficient conditions for the consensus of multi-agent systems are obtained. And we give the expression of the weighted average consensus value for our consensus protocol. Finally, numerical examples are presented to illustrate the theoretical results.展开更多
In this paper,the authors tackle a fixed-time average-tracking problem for multi-agent systems which do not require velocity measurements and are affected by external mismatched and matched disturbances.The objective ...In this paper,the authors tackle a fixed-time average-tracking problem for multi-agent systems which do not require velocity measurements and are affected by external mismatched and matched disturbances.The objective requires the considered agents with second-order dynamics to follow the average value of several time-varying reference signals,each of which is acquired by only one agent.First of all,the average value is estimated by using a novel distributed average estimator in a fixed time.Second,an original observer is created to provide estimated values in a fixed time for external mismatched and matched disturbances as well as unmeasured velocities of agents.Then,the authors propose a novel fixed-time anti-disturbance average-tracking protocol with the aid of the observer and a sliding mode surface.In the end,the feasibility of theoretical analysis is illustrated by some simulation experiments.展开更多
在大动态范围的复杂通信系统中,自动增益控制系统的性能起着至关重要的作用。针对传统自动增益控制系统的动态范围较小及收敛速度较慢的问题,提出了一种大动态范围数字AGC快速控制算法。该算法采用射频峰值检测以及大信号指示的方式实...在大动态范围的复杂通信系统中,自动增益控制系统的性能起着至关重要的作用。针对传统自动增益控制系统的动态范围较小及收敛速度较慢的问题,提出了一种大动态范围数字AGC快速控制算法。该算法采用射频峰值检测以及大信号指示的方式实现对射频功率的快速检测;采用平均功率的方式对中频信号功率进行滑动平均,准确获取中频信号的平均功率;结合中频和射频增益控制策略,对接收信道的增益进行分配以及快速控制,使得射频信号经过射频单元后始终位于模数转换器(Analog to Digital Converter,ADC)的动态范围内,从而实现射频信号的稳定接收。仿真结果表明,相较于传统算法,所提算法的收敛时间由毫秒级提高到了微秒级,动态范围大幅提升。展开更多
基金supported by the National Natural Science Foundation of China under Grant No.60904064, 61174094the Program for New Century Excellent Talents in University of China(NCET-10-0506)the Tianjin Natural Science Foundation of China under Grant No.09JCYBJC01700
文摘This paper investigates the average-consensus problem of multi-agent systems with direct and weighted topologies. Event-triggered control laws are adopted so as to reduce the frequency of individual control updating since the agents may be resource-limited in many real systems. The discrete time instants where the events are triggered are determined by a trigger function with respect to a certain measurement error. A centralized average-consensus protocol is proposed first for networks with fixed interaction topology, the stability and influencing factors of which are also analyzed. The design of trigger functions for networks with variable topology is also discussed. Then the results are extended to the decentralized counterpart, in which agents require only the information of their neighbors. Numerical examples are also provided that demonstrate the effectiveness of the theoretical results.
基金the National Natural Science Foundation of China(No.60674027)China Postdoctoral Science Foundation(No.20070410336)the Postdoctor Foundation of Jiangsu Province(No.0602042B).
文摘A new class of hybrid impulsive and switching models are introduced and their robust exponential stability and control synthesis are addressed. The proposed switched system is composed of stable subsystems and unstable subsystems, which not only involves state delay and norm-bounded time-varying parameter uncertainties, but also contains the impulsive switching effects between the subsystems. Based on the extension of the system dimension and the concept of average dwell time, a kind of practically useful switching rule is presented which guarantees the desired robust exponential stability. A switched state feedback controller is also given.
基金supported by the National Natural Science Foundation of China(6127312661363002+3 种基金61374104)the Natural Science Foundation of Guangdong Province(10251064101000008S2012010009675)the Fundamental Research Funds for the Central Universities(2012ZM0059)
文摘This paper studies the weighted average consensus problem for networks of agents with fixed directed asymmetric unbalance information exchange topology. We suppose that the classical distributed consensus protocol is destroyed by diverse time-delays which include communication time-delay and self time-delay. Based on the generalized Nyquist stability criterion and the Gerschgorin disk theorem, some sufficient conditions for the consensus of multi-agent systems are obtained. And we give the expression of the weighted average consensus value for our consensus protocol. Finally, numerical examples are presented to illustrate the theoretical results.
基金supported by the National Natural Science Foundation of China under Grant Nos.61973139,61973082 and 61473138the Fundamental Research Funds for the Central Universities under Grant No.JUSRP22014。
文摘In this paper,the authors tackle a fixed-time average-tracking problem for multi-agent systems which do not require velocity measurements and are affected by external mismatched and matched disturbances.The objective requires the considered agents with second-order dynamics to follow the average value of several time-varying reference signals,each of which is acquired by only one agent.First of all,the average value is estimated by using a novel distributed average estimator in a fixed time.Second,an original observer is created to provide estimated values in a fixed time for external mismatched and matched disturbances as well as unmeasured velocities of agents.Then,the authors propose a novel fixed-time anti-disturbance average-tracking protocol with the aid of the observer and a sliding mode surface.In the end,the feasibility of theoretical analysis is illustrated by some simulation experiments.
文摘在大动态范围的复杂通信系统中,自动增益控制系统的性能起着至关重要的作用。针对传统自动增益控制系统的动态范围较小及收敛速度较慢的问题,提出了一种大动态范围数字AGC快速控制算法。该算法采用射频峰值检测以及大信号指示的方式实现对射频功率的快速检测;采用平均功率的方式对中频信号功率进行滑动平均,准确获取中频信号的平均功率;结合中频和射频增益控制策略,对接收信道的增益进行分配以及快速控制,使得射频信号经过射频单元后始终位于模数转换器(Analog to Digital Converter,ADC)的动态范围内,从而实现射频信号的稳定接收。仿真结果表明,相较于传统算法,所提算法的收敛时间由毫秒级提高到了微秒级,动态范围大幅提升。
