力反馈时延遥操作系统的时延相关稳定性分析

当力反馈双边控制系统的主从端之间存在时延时,系统的稳定性和透明性会遭到破坏.无源性方法能保证系统的时延无关稳定性,但由于稳定性和透明性冲突,系统的透明性较差.本文利用绝对稳定性理论推导出一种新的双边控制算法.它以时延相关稳定性代替时延无关稳定性作为控制设计的目标,牺牲一部分不必要的稳定裕度以改善系统的透明性.它在保证系统稳定性的前提下使系统具有更好的透明性,最后用仿真进行了验证.     

遥控系统理想性能的实现和实验研究

本文对主从遥控系统理想性能的实现进行了理论分析和实验研究。对于位置／力控制的遥控机器人，理想性能就是要实现主从操作器的位置跟踪和力跟踪。文中首先通过分析得到了一组控制规律，利用这组控制规律就可以实现理想性能，而且这组控制规律由于引入了力微分信号而比较简单。接着以无源性为基础，对系统的稳定性进行了研究。最后通过实验可知在从操作器同环境有或无作用的情况下，主从遥控系统都可以实现理想性能。     

一类具有离散与分布时滞的控制系统的绝对稳定性

用Lyapunov泛函法研究一类具有离散与分布时滞的控制系统的绝对稳定性问题。给出了这类系统绝对稳定的时滞相关准则。应用实例表明,与现有结果相比,所得结果具有较小的保守性。     

离散时间系统下的积分二次约束方法的几个问题

研究了离散情形下的反馈系统的稳定性问题,利用新近发展起来的积分二次约束 (IQC)方法,对离散系统的反馈连接问题,给出了其稳定性分析准则和一些必要条件,这些结果 适用于时不变与时变系统.其次,利用已有的结果.得到了离散时变系统MIMO情况下的绝对 稳定性问题的一个判据.最后,利用一个较强的IQC定义,给出了判断某一类反馈系统稳定的 充分必要条件.     

主动队列管理中增强型自适应虚拟队列管理算法之设计及稳定性分析

提出了一种基于速率的增强自适应虚拟队列管理算法(EAVQ). 在该算法中引入主从拥塞尺度和期望链路利用比的概念; 以输入速率为主要拥塞尺度, 以便保留原有自适应虚拟队列管理算法(AVQ)中响应速度快、队列时延短、链路利用率高等优点. 同时, 以期望链路利用比为辅助拥塞准则, 设计了一种基于速率的期望链路利用比自适应机制, 解决了AVQ中参数设定困难、队列抗干扰能力弱, 及存在链路损失等缺点; 在改善系统动态性能的同时保证了链路容量的充分利用. 在线性化基础上给出了一般网络结构下TCP/EAVQ系统的局部稳定条件. 通过仿真验证了EAVQ的有效性.     

具有多个非线性项的一般Lurie间接系统的绝对稳定性

为了研究具有多个非线性项的一般Lurie间接系统的绝对稳定性问题,介绍了关于变 元σ绝对稳定的概念.通过对关于变元σ绝对稳定性的研究,得到了此类系统绝对稳定的充要 条件,并给出了一些简洁实用的充分条件.     

一类新的Takagi-Sugeno模糊时滞系统的稳定性准则

本文提出一种新的时滞划分方法—变时滞划分法,以解决连续延时Takagi-Sugeno模糊系统的稳定性和镇定性问题.不同于已有的文献,用可变参数将时变时滞区间[0,d(t)]划分为若干个可变子区间,并得出模糊时滞系统的新的时滞相关稳定性准则.本文提出的新方法能充分利用时滞子区间的内部信息,因此新的时滞相关稳定性准则比以往结果具有更小的保守性.基于Lyapunov稳定性理论,以线性矩阵不等式形式给出T--S模糊系统的新的时滞相关稳定性准则,并将稳定性和镇定性研究结果扩展到具有不确定参数的T--S模糊系统.仿真实例证明了本文方法降低保守性的有效性.     

云中面向图像并行计算的数据分布策略

有效地减少云计算系统中对计算任务的处理响应时间,并使各计算机节点负载均衡,数据分布算法是相当重要的.提出了一种面向图像并行计算的适用于主从类型云计算系统结构的数据分布策略,设计节点性能函数来表示节点的处理能力,根据节点间的性能比率进行任务数据量的分布,结合链路带宽制定数据发送的顺序.模拟实验结果表明,该算法适用于云计算环境,能明显提高系统的数据处理效率.     

采煤机牵引系统双电机功率平衡控制策略

随着采煤机装机功率和开采能力的提升,牵引系统控制效果及动态性能已成为影响采煤机工作稳定性的重要因素.目前,采煤机电牵引系统双电机控制策略多采用传统的主从控制,其同步性能存在滞后问题,容易导致牵引电机偏载.此外,系统在控制算法方面多采用传统PI控制,对于容易发生参数摄动及负载变化频繁的牵引系统而言,传统PI控制的控制性能不佳.为提高采煤机牵引系统驱动性能并实现牵引电机功率平衡,根据采煤机牵引系统结构,本文提出了一种基于自抗扰控制的转速主从、转矩交叉耦合控制的双电机控制策略,并对控制策略进行了仿真分析和实验研究.结果表明,本文所提出控制策略实现了牵引系统功率平衡并提升了系统的控制性能.     

Lurie控制系统的关联绝对稳定性-双线性矩阵不等式方法

研究任意两个相互独立的Lurie控制系统能否通过关联或协调控制组成绝对稳定大系统的问题,给出两个Lurie控制系统可关联绝对稳定的充分条件,并给出了计算关联矩阵的双线性矩阵不等式方法.研究结果表明:两个非绝对稳定的系统可以通过关联或协调控制来实现关联大系统的绝对稳定性,取消了大系统稳定性分析中对关联的不合理限制.文末给出了本文结果的数值例子.     

用于微创外科手术的遥控机器人系统研究现状及趋势

用于微创外科手术(Minimally Invasive Surgery 简称MIS)的主从式遥控机器人 系统是医疗中的MIS技术与遥操作技术的结合, 本文主要对具有力觉临场感的比率遥控机器 人用于MIS时的控制特点要求和控制理论技术的研究现状进行了综述,强调了用于MIS和用于 生物工程、微机械等领域的遥控机器人系统在控制上的异同, 对用于MIS的比率遥控机器人 系统控制中有待研究的一些关键问题提出了见解.     

离散双线性系统的稳定控制分析

对于一般离散双线性系统 ,本文提出了系统在线性反馈下的稳定性判据和最小吸引域 ,并给出了一种简单的控制方案 ,保证闭环系统在原点的一致渐近稳定性 .仿真结果证明了该方法的有效性 .所得稳定性判据对于选择合适的控制方案具有重要的指导意义 .     

Analytical decoupling control strategy using a unity feedback control structure for MIMO processes with time delays

An analytical decoupling control method is proposed for multiple-input–multiple-output (MIMO) processes with multiple time delays. The desired diagonal system transfer matrix is proposed first in terms of the H₂ optimal performance specification, resulting in the ideal desired decoupling controller matrix derived within the framework of a unity feedback control structure. It is demonstrated that dead-time compensators must be enclosed in the decoupling controller matrix to realize absolute decoupling for MIMO processes with multiple time delays. To alleviate the difficulties associated with the implementation, the ideal desired decoupling controller matrix is transformed into a practical form using an analytical approximation approach. Correspondingly, the stability of the resultant control system is assessed, together with its robust stability in the presence of process uncertainties. An on-line tuning rule for the single adjustable parameter of each column controllers in the decoupling controller matrix is given to cope with the process unmodeled dynamics. Finally, illustrative examples are given to show the superiority of the proposed method over the recently improved decoupling control methods.     

空间力觉临场感遥控作业系统的时延无条件稳定性分析

空间遥控作业系统中存在很长的通信时延,造成遥控作业系统的不稳定和操作性能的降低,为此,从建立力觉临场感遥控作业系统的时延动力学方程出发,利用差分微分方程对系统的无条件稳定性进行分析,实验结果表明该分析方法是行之有效的。     

Adaptive Control of a Two-Link Robot Using Batch Least-Square Identifier

We design a regulation-triggered adaptive controller for robot manipulators to efficiently estimate unknown parameters and to achieve asymptotic stability in the presence of coupled uncertainties. Robot manipulators are widely used in telemanipulation systems where they are subject to model and environmental uncertainties. Using conventional control algorithms on such systems can cause not only poor control performance, but also expensive computational costs and catastrophic instabilities. Therefore, system uncertainties need to be estimated through designing a computationally efficient adaptive control law. We focus on robot manipulators as an example of a highly nonlinear system. As a case study, a 2-DOF manipulator subject to four parametric uncertainties is investigated. First, the dynamic equations of the manipulator are derived, and the corresponding regressor matrix is constructed for the unknown parameters. For a general nonlinear system, a theorem is presented to guarantee the asymptotic stability of the system and the convergence of parameters’ estimations. Finally, simulation results are discussed for a two-link manipulator, and the performance of the proposed scheme is thoroughly evaluated.      

Scalable Clock Synchronization Analysis: A Symmetric Noncooperative Output Feedback Tubes-MPC Approach

In the cyber-physical environment, the clock synchronization algorithm is required to have better expansion for network scale. In this paper, a new measurement model of observability under the equivalent transformation of minimum mean square error (MMSE) is constructed based on basic measurement unit (BMU), which can realize the scaled expansion of MMSE measurement. Based on the state updating equation of absolute clock and the decoupled measurement model of MMSE-like equivalence, which is proposed to calculate the positive definite invariant set by using the theoretical-practical Luenberger observer as the synthetical observer, the local noncooperative optimal control problem is built, and the clock synchronization system driven by the ideal state of local clock can reach the exponential convergence for synchronization performance. Different from the problem of general linear system regulators, the state estimation error and state control error are analyzed in the established affine system based on the set-theory-in-control to achieve the quantification of state deviation caused by noise interference. Based on the BMU for isomorphic state map, the synchronization performance of clock states between multiple sets of representative nodes is evaluated, and the scale of evaluated system can be still expanded. After the synchronization is completed, the state of perturbation system remains in the maximum range of measurement accuracy, and the state of nominal system can be stabilized at the ideal state for local clock and realizes the exponential convergence of the clock synchronization system.      

Performance analysis and improvement in model reference adaptivecontrol

The purpose of this paper is to address the issue of performance by using two additional criteria to assess performance in the ideal and nonideal situations. They are the mean square tracking error criterion and the L_∞ tracking error bound criterion. We use these criteria to examine the performance of a standard model reference adaptive controller and motivate the design of a modified scheme that can have an arbitrarily improved nominal performance in the ideal case and in the presence of bounded input disturbances. It is shown that for these cases the modified scheme can provide an arbitrarily improved zero-state transient performance and an arbitrary reduction in the size of possible bursts that may occur at steady state. As in every robust control design, the nominal performance has to be traded off with robust stability and therefore the improvement in performance achieved by the proposed scheme is limited by the size of the unmodeled dynamics, as established in the paper     

Set stability of controlled Chua’s circuit under a non-smooth controller with the absolute value

Chua’s circuit is a typical system with the piecewise-smooth vector field via the absolute value. A new piecewise-linear feedback control scheme with the absolute value is introduced to realize stabilization of sets of the controlled Chua’s circuit. The equilibrium sets and the global asymptotical stability with respect to several invariant sets, which may consist of both admissible and boundary equilibrium points or equilibrium manifolds, are investigated for the controlled Chua’s circuit system. The non-smooth controller has a simple structure and available control properties, and it is easy to be applied in engineering practice. It is shown by numerical simulations that this controller can effectively realize chaos control and stabilization of equilibrium states.     

火炸药烘干过程中的温度控制系统设计

针对火炸药烘干系统的温度控制要求,采用传统PID控制技术控制系统中的水温,可以满足控制要求,但对风温系统来讲,适应性差,超调量大,稳定性低,控制效果不够理想。采用自适应模糊PID控制技术控制风温,可以实现PID参数自整定,提高控制精度、系统稳定性。现场试验表明:自适应模糊PID控制方法自适应性强,能够使烘干温度保持恒定,满足火炸药烘干温度控制的要求。