Periodic Solutions of a Cooperative System with State Feedback Control

In this paper, we propose a semi-continuous dynamical system to study the cooperative system with feedback control. Based on geometrical analysis and the analogue of Poincare criterion, the existence and stability of the positive order one periodic solutions are given. Numerical results are carried out to illustrate the feasibility of our main results.

Robot Position Control Using Force Information for Cooperative Work in Remote Robot Systems with Force Feedback

This paper proposes robot position control using force information for cooperative work between two remote robot systems with force feedback in each of which a user operates a remote robot by using a haptic interface device while observing work of the robot with a video camera. We also investigate the effect of the proposed control by experiment. As cooperative work, we deal with work in which two robots carry an object together. The robot position control using force information finely adjusts the position of the robot arm to reduce the force applied to the object. Thus, the purpose of the control is to avoid large force so that the object is not broken. In our experiment, we make a comparison among the following three cases in order to clarify how to carry out the control effectively. In the first case, the two robots are operated manually by a user with his/her both hands. In the second case, one robot is operated manually by a user, and the other robot is moved automatically under the proposed control. In the last case, the object is carried directly by a human instead of the robot which is operated by the user in the second case. As a result, experimental results demonstrate that the control can help each system operated manually by the user to carry the object smoothly.

Cooperative output tracking of multi-agent systems under finite time

The cooperative output tracking problem of multi-agent systems in finite time is considered.In order to enable the agents to quickly track and converge to external system within a finite time,a novel distributed output feedback control strategy based on the finite-time state observer is designed.This distributed finite-time observer can not only solve cooperative output tracking problems when the agents can not get external system signal,but also make the systems have a faster convergence and a good robustness.The stability of the system in finite time is proved based on Lyapunov function.Numerical simulations results have been provided to demonstrate the effectiveness of the proposed protocol.

具有反馈控制和时滞的比率依赖随机Lotka-Volterra竞争−合作模型的动力学分析

研究了一类新的具有反馈控制和时滞的比率依赖随机三种群Lotka-Volterra竞争−合作生物模型.首先,证明了模型存在唯一的全局正解.其次,通过构造适当的Lyapunov函数,证明了模型的解是随机最终有界的.最后,运用伊藤公式和微分不等式放缩,得到了种群灭绝的充分条件.

反馈控制Lotka-Volterra合作系统稳定性研究

研究具有反馈控制的两种群Lotka-Volterra合作系统正平衡点的稳定性.通过构造适当的Lyapunov函数得到一组保证正平衡点全局吸引的充分性条件.我们的结果表明在原系统存在正平衡点时,反馈控制变量仅能改变正平衡点的位置,而不会改变正平衡点的稳定性.

基于关节双位置反馈的柔性协作机械臂零力控制

零力控制是协作机械臂实现拖动示教的核心问题之一,目前方法多依赖于附加力/力矩传感器,其虽能保证测量精度,但会增加系统复杂程度及成本。提出一种基于关节双位置反馈的柔性协作机械臂零力控制方法,该方法可在无外加传感器条件下实现机械臂零力控制。首先,基于波发生器与柔轮柔性特性,建立了谐波传动关节的动力学模型;其次,基于谐波传动关节刚度辨识方法,建立了基于双位置反馈的柔性关节力矩估测方法;再次,建立了简化重力矩补偿模型,并考虑关节转动过程中的粘滞摩擦和Stribeck库伦摩擦,完善了关节摩擦力矩模型,基于此,实现对关节重力矩和摩擦力矩补偿,实现机械臂零力控制;最后,搭建谐波传动一体化关节和机械臂样机平台,并进行了实验研究,结果表明,所提方法可有效实现无附加力/力矩传感器条件下的谐波传动机械臂零力控制。

基于合作捕猎和恐惧效应的捕食-食饵模型定性分析与反馈控制

在自然界中,种群与种群之间的关系错综复杂.捕食者之间的合作捕猎行为以及食饵对捕食者的恐惧会对种群间的动力学行为带来一定的影响,为此本文研究一类具有合作捕猎和恐惧效应的捕食-食饵模型.首先,建立具有Smith型增长率和恐惧效应以及捕食者合作捕猎的捕食-食饵模型,分析该模型解的存在性与一致有界性,并给出平衡点存在和稳定的条件;其次,通过对捕食者进行控制,建立基于反馈控制的捕食-食饵模型,讨论阶-1周期解的存在性和稳定性;最后,借助于MATLAB进行数值模拟,对以上理论结果进行验证和说明.

具有未知增长率的一类上三角非线性多智能体系统的协同控制

基于有向领导者-追随者型的网络拓扑结构,研究了一类具有未知增长率的上三角非线性多智能体系统的协同控制问题。首先,通过引入坐标变换,将原系统转换为带有时间增益的等效系统;其次,针对标称系统进行控制器设计,获得原系统的分布式时变状态反馈控制器。所设计的控制器能够保证追随者与领导者的输出跟踪误差有界,且闭环系统所有信号有界。最后,利用仿真实例验证了控制方案的有效性。

具反馈控制和时滞的Lotka-Volterra专性合作系统的全局稳定性

研究一类具反馈控制和时滞的Lotka-Volterra专性合作系统。通过构造合适的Lyapunov函数,建立了保证系统正平衡点全局稳定性的充分条件。结果表明,系统的正平衡点位置虽然发生了改变,但是反馈控制变量和时滞并没有改变正平衡点的全局稳定性。

具时滞和反馈控制的Lotka-Volterra合作系统的全局稳定性

研究一类具时滞和反馈控制的Lotka-Volterra合作系统。在不同时滞条件下,通过构建合适的Lyapunov函数,建立保证系统正平衡点全局稳定的充分条件。结果表明:时滞的存在并没有改变系统正平衡点全局稳定性的充分条件,因此,离散时滞属于无害时滞。

STABILITY OF LOTKA-VOLTERRA COOPERATION SYSTEM WITH SINGLE FEEDBACK CONTROL

In this paper, a Lotka-Volterra cooperation system with single feedback control is proposed and studied. We investigate the local stability and the global stability of the system. Our study shows that with suitable restriction on the coefficients of the feedback control variable, the system can still remain globally stable or become extinct, which shows that the feedback control variable plays a very important role in the dynamics behaviors of the system.

Periodicity and Stability in Periodic n-Species Lotka-Volterra Competition System with Feedback Controls and Deviating Arguments

By using the method of coincidence degree and Lyapunov functional, a set ofeasily applicable criteria are established for the global existence and global asymptotic stabilityof strictly positive (componentwise) periodic solution of a periodic n-species Lotka-Volterracompetition system with feedback controls and several deviating arguments. The problem considered inthis paper is in many aspects more general and incorporate as special cases various problems whichhave been studied extensively in the literature. Moreover, our new criteria, which improve andgeneralize some well known results, can be easily checked.

PERMANENCE AND GLOBAL ATTRACTIVITY OF N-SPECIES COOPERATION SYSTEM WITH DISCRETE TIME DELAYS AND FEEDBACK CONTROLS

In this paper, we consider the N-species cooperation system with discrete time delays and feedback controls. By using the differential inequality theory and constructing a suitable Lyapunov functional, we obtain sufficient conditions which guarantee the permanence and the global attractivity of the system.

THE STABILITY OF A REACTION-DIFFUSION LOTKA-VOLTERRA COMPETITIVE SYSTEM WITH NONLOCAL DELAYS AND FEEDBACK CONTROLS

In this paper, we consider a Lotka-Volterra competitive system with nonlocal delays and feedback controls. Using the Lyapunov functional and iterative technique method, we investigate the global stability and extinction of the system. Also, we show the influence of feedback controls on dynamic behaviors of the system. Some examples are presented to verify our main results.

GLOBAL ASYMPTOTIC STABILITY IN NONAUTONOMOUS LOTKA-VOLTERRA COMPETITIVE SYSTEM WITH INFINITE DELAY AND FEEDBACK CONTROLS

In this paper, we study a nonautonomous Lotka-Volterra competitive system with infnite delay and feedback controls. By means of a suitable Lyapunov functional, we establish sufcient conditions which guarantee the global asymptotic stability of the system.

A LOTKA-VOLTERRA PREY-PREDATOR SYSTEM WITH FEEDBACK CONTROL EFFECT

In this paper, we propose a Lotka-Volterra prey-predator system with discrete delays and feedback control. Firstly, we show that solution of the system is bounded. Secondly, we obtain sufficient condition for the global stability of the unique positive equilibrium to the system.

非完整移动机器人目标环绕动态反馈线性化控制

本文针对多个非完整移动机器人对静止或运动目标的环绕追踪问题进行研究.每个机器人仅通过自身和其相邻的机器人的位置与方向信息以及所追踪的目标的位置信息来协调其运动.首先,提出了一种基于动态反馈线性化方法的分布式控制策略,并引入一个控制机器人之间相对角间距的非线性函数,控制机器人间的相对角间距.使多个机器人能够以期望的与目标之间的相对距离、环绕速度和机器人之间的相对角间距对目标进行追踪.然后,利用Lyapunov工具对控制算法进行了渐近稳定性和收敛性分析.最后构建了多移动机器人实验平台,进行了数值仿真和实验验证,仿真和实验的运行结果表明了所提出算法的有效性.

电力系统一二次调频的反馈微分博弈协同控制

风能等间歇式能源并网将是未来电网发展趋势,其输出功率的波动将加剧一二次调频之间的冲突反调问题.本文将反馈微分博弈应用于电力系统频率控制中,建立起一二次调频的协同控制模型,并考虑调速器死区、控制动作幅值限制、机组爬坡速率约束等工程实际因素,用协同进化算法求得该模型的反馈纳什均衡解.用仿真验证了该方法在满足各种工程因素下有效解决一二次调频的冲突反调问题,充分挖掘了系统蕴藏的调频能力.

大规模城市轨道交通网常态限流方案编制

为了给大规模轨道交通网高峰时段常态限流方案编制提供科学的计算依据,提出一种基于运输能力瓶颈反馈疏解策略的限流方案构造算法.算法核心思想为"溯源",即对流经运输能力瓶颈区间的主要客流源头站实施有效控制,从而达到疏解能力瓶颈区间的目的.该算法以车站进站客流与区间通过客流内在关系为基础,利用反馈机制对路网能力瓶颈区间进行疏解,反向确定限流车站、限流时段及限流强度.方案构建过程中充分考虑了路网能力瓶颈间关联性、多个车站间控制协同性、以及控制时段间需求的传递性,实现限流方案的科学、高效编制.基于所提出算法开发了轨道交通限流组织决策支持系统,以2017年北京地铁网为对象进行实证研究,结果显示:所构建算法能高效编制限流方案,通过与实际限流方案实施后的断面量对比评估,表明所构建方案能有效降低乘客进站延误时间,验证了算法的合理性和准确性.该研究能够为轨道交通网络层常态限流方案编制提供理论与方法支撑,具有良好的实际应用价值.

基于非线性干扰观测器的航天器相对姿轨耦合控制

针对带挠性附件的服务航天器在近距离逼近失控目标航天器时的控制问题,考虑由于推进安装偏差导致的姿轨耦合,通过选用相对位置和相对姿态四元数作为状态向量,建立了服务航天器与失控目标航天器的相对位置和姿态动力学方程。考虑服务航天器的挠性附件影响,挠性振动可以视为位置和姿态控制系统微分有界的干扰。基于反馈线性化方法提出了非线性反馈控制律,设计了非线性干扰观测器,用于补偿可建模干扰,并基于所提非线性反馈控制律和非线性干扰观测器设计了复合控制器,其中非线性干扰观测器用于补偿挠性附件产生的干扰。数字仿真及半物理实物闭环验证表明,利用所设计的复合控制器能够有效补偿干扰,同时在对失控目标航天器跟踪时具有很好的鲁棒性。