全航速升力反馈减摇鳍控制策略研究

提出全航速减摇鳍控制策略,对低航速和中航速切换策略进行研究．采用升力反馈封装鳍角到升力的不确定性,避免在零航速和低航速下复杂的控制规律;同时,基于T-S模型将横摇非线性不确定系统转化为线性时变系统,并将控制中的约束非线性优化问题转化为二次规划问题,避免了预测控制中的非线性优化在线求解．以某船为例,给出了低中航速的切换控制策略,仿真结果表明了该方法可以使减摇鳍满足全航速减摇要求．     

焦炉荒煤气传输系统多模型PI-GPC的仿真研究

充分考虑大多数焦炉荒煤气传输系统的对象特性与运行工况密切相关的实际特点,利用PI控制和广义预测控制的优点推导出一种改进型的广义预测控制策略。同时,在不同工况点下建立相应的控制器,并给出一种改进的控制器切换方法和切换之后的控制量补偿方法,以解决因为控制器切换和工艺设定值的改变而导致的切换扰动和系统的震荡、超调。通过利用改进的多模型广义预测控制,使得系统更具有鲁棒性、快速性。仿真结果证实了该控制策略的优越性。     

虚拟同步发电机的无缝切换控制技术

对微电网中并网逆变器的虚拟同步发电机(VSG)控制策略进行了研究。首先,搭建了VSG控制的功频调节部分和励磁调节部分。VSG通过模拟同步发电机的惯性和阻尼特性,实现了并网和离网的独立运行,但是在并离网切换时容易出现电流和电压冲击。为实现并离网的平滑切换,提出了一种离网模式下恒压/恒频控制、并网模式下VSG控制的控制策略。在离网运行时,恒压/恒频控制模式为负载提供电压和频率的支撑;在并网运行时,由VSG控制模式提供。同时,详细地分析了调差系数、阻尼系数和转动惯量对功频特性的影响。最后,利用Matlab/Simulink搭建仿真模型,验证该控制策略的有效性。仿真结果表明:该控制策略解决了微电网在不同模式之间的无缝切换问题;与传统的切换过程相比,减小了切换过程中的电压和电流冲击,提高了微电网在运行过程中的稳定性,可以应用于多微源并联的微电网。     

宝钢焦输送系统流程控制策略设计

改造后的宝钢焦输送系统,在工艺上要求每个起点焦库(焦台)的焦炭可以送到任意一个高炉焦库,并能实现更为灵活的流程自动切换。实现这些功能的关键是设计一个清晰合理的流程控制策略。简要介绍了焦输送工艺和控制系统硬件组态,对该系统流程控制策略中的重要组成部分进行了说明。其中,依据工艺和设备间的联锁把分散独立的设备归属于不同的流程块,简化了控制对象;把流程状态划分为暂态和稳态,在暂态中实现切换;通过建立严密的流程冲突规则来实现各流程的相互协调。实践证明,依据该控制策略实现的流程控制自动化水平高,切换灵活,运行可靠,该策略对类似物料输送的流程控制有较好的借鉴作用。     

有源电力滤波器切换跟踪与优化控制

为了提高有源电力滤波器的动态性能, 基于切换系统理论研究其电流跟踪控制问题. 首先, 建立系统的切换动态模型, 根据切换系统理论和空间电压矢量法证明二次稳定性, 并设计相应的切换控制序列. 考虑到控制器的数字化实现, 建立系统的离散切换系统模型, 提出在采样周期内使系统性能最优的切换控制策略. 仿真结果表明, 该控制策略能实现对指令电流的精确跟踪, 降低功率器件的开关频率, 从而有效地提高系统的动态性能.

     

一种基于混合视觉伺服的切换控制方法

为解决目标远离摄像机视野问题,本文提出了一种基于混合视觉伺服的切换控制方法,根据目标在图像平面的位置,通过在两种具有不同特性的控制策略之间进行切换完成视觉伺服任务.采用的混合视觉伺服方法实现了平动和转动自由度的解耦,当目标位于图像平面中心区域时,采用控制策略使转动自由度误差指数级减小;当目标位于边界区域时,切换到另一种控制策略,使目标重新回到中心区域,通过切换控制最终完成伺服任务.仿真实验验证了提出的基于混合视觉伺服切换控制方法的有效性.     

积分事件触发策略下的线性多智能体系统领导跟随一致性

研究有向切换拓扑下线性多智能体系统的事件触发一致跟踪问题.大多数已有的工作研究了固定拓扑下的事件触发控制,然而,当智能体间联系随时间发生改变或通信拓扑随时间发生变化时,该控制策略失效.鉴于此,在考虑切换拓扑的基础上提出一种基于积分型事件触发的控制策略.首先,当拓扑图包含一棵生成树且领导者是根节点时,利用Lyapunov稳定性理论、代数图论和矩阵变换,基于积分型事件触发控制协议,在切换拓扑下多智能体系统达到领导跟随一致性;然后,当存在多个领导者时,基于设计的触发机制在切换拓扑下多智能体系统实现包含控制,上述两种情况下闭环系统均不存在Zeno现象;最后,通过仿真结果验证控制策略的有效性.     

印染行业不可靠生产系统生产控制模型

基于印染行业自身特性,建立了适合于该行业特点的不可靠生产系统的生产控制模型。该模型不但考虑了生产设备时有故障和修复事件的发生,而且也把由于生产系统操作条件及生产原料属性的波动造成合格产品呈随机分布的情况纳入模型框架,其中当不同产品间生产切换时,所需切换时间及切换费用也被引入模型,并假设此时设备的故障过程为Markov过程。结合单设备单产品情况,给出了其最优生产控制策略。为实现印染行业生产的优化控制及建立完善的MES系统提供了理论支持。     

多指灵巧手的位置/力矩控制

提出了一种新的多指手位置/力矩控制策略.该策略基于滑模位置控制和PD力矩控制分别实现自由空间中的轨迹跟踪和约束空间中的力矩跟踪,利用简单的系统观测器实现灵巧手在过渡过程中的控制模式切换.该策略具有很好的位置/力矩跟踪能力,并且可以保证过渡过程的稳定性.实验结果证明了该控制策略的有效性和可行性.     

一类非线性系统的次优控制研究

考虑一类关系度不确定且零动态稳定的非线性系统的控制器设计问题．利用预测控制概念,通过选用较为全面的二次型性能指标,对输出进行高阶泰勒级数展开,推导出一种非切换的解析次优控制律,进而得出了在该控制律下闭环系统局部稳定的充分条件．仿真例子验证了该控制算法具有较好的动态性能,与已有的近似线性化方法相比,显示了该控制策略的优越性．     

Robust performance analysis and synthesis of linear polytopic discrete-time periodic systems via LMIs

A particular class of uncertain linear discrete-time periodic systems is considered. The problem of robust stabilization of real polytopic linear discrete-time periodic systems via a periodic state-feedback control law is tackled here, along with performance optimization. Using additional slack variables and the periodic Lyapunov lemma, an extended sufficient condition of robust stabilization is proposed. Based on periodic parameter-dependent Lyapunov functions, this last condition is shown to be always less conservative than the more classic one based on the quadratic stability framework. This is illustrated on a numerical example from the literature.     

Stabilization of uncertain nonholonomic systems via time-varying sliding mode control

This note addresses the robust stabilization problem for a general class of nonholonomic systems in the presence of drift uncertainties. The control approach developed is based on the combined applications of the sliding mode control technique and nonlinear time-varying systems theory. First, some properties of nonlinear time-varying systems are introduced for the purpose of designing sliding mode controller. An explicit time-varying feedback form is provided to guarantee the existence and uniqueness of periodic time-varying solution for the corresponding linear periodic partial differential equation. Second, an explicit discontinuous feedback control law is presented to guarantee the existence of sliding mode. The first integrals obtained by the previous periodic partial differential equation are then directly used to determine the switching function. The uniform asymptotic stability of the closed loop system is proved via the invariance principle of nonlinear time-varying systems. Finally, an example is given to illustrate the proposed approach.     

基于LMI 的线性时变周期系统的稳定性及鲁棒控制

线性时变周期（LTVP）系统的能控性、能观性、稳定性、镇定性等问题的研究一般需要依赖于系统的状态转移矩阵.但是,获得一般LTVP系统的状态转移矩阵十分困难.借鉴解决线性定常系统鲁棒控制问题的思路,把周期问题转化为一类范数有界问题,避开了求取系统状态转移矩阵;设计了基于LMI的使LTVP系统镇定的无记忆反馈控制器和基于LMI的使LTVP系统鲁棒镇定无记忆反馈控制器,仿真算例验证了所提出方法的有效性.     

Supervisory control of air–fuel ratio in spark ignition engines

The problem of air–fuel ratio stabilization in spark ignition engines is addressed in this paper. The proposed strategy consists of proper switching among two control laws to improve quality of the closed-loop system. The first control law is based on an a priori off-line identified engine model and ensures robust and reliable stabilization of the system at large, while the second control law is adaptive, it provides on-line adaptive adjustment to the current fluctuations and improves accuracy of the closed-loop system. The supervisor realizes a switching rule between these control laws providing better performance of regulation. Results of implementation on two vehicles are reported and discussed.     

不对称欠驱动水面机器人事件触发全局渐近镇定控制

本文研究了不对称欠驱动水面机器人事件触发全局渐近镇定控制问题.首先,引入坐标变换将系统全局渐近镇定控制问题转化为变换后模型欠驱动子系统的全局渐近镇定控制问题,利用周期时间函数构造时变辅助变量提出了一种时变连续的镇定控制律,并结合切换门限事件触发机制设计实际的事件触发推力与力矩控制输入使闭环系统全局渐近稳定.所提出的方法仅在系统满足触发条件时对控制器进行更新,能够节约系统资源以及减少执行器操纵次数,同时不会降低原有的控制品质.最后,通过仿真验证了所提出方法的有效性.     

Decentralized robust control of uncertain Markov jump parameter systems via output feedback

This paper addresses the problem of decentralized robust stabilization and control for a class of uncertain Markov jump parameter systems. Control is via output feedback and knowledge of the discrete Markov state. It is shown that the existence of a solution to a collection of mode-dependent coupled algebraic Riccati equations and inequalities, which depend on certain additional parameters, is both necessary and sufficient for the existence of a robust decentralized switching controller. A guaranteed upper bound on robust performance is also given. To obtain a controller which satisfies this bound, an optimization problem involving rank constrained linear matrix inequalities is introduced, and a numerical approach for solving this problem is presented. To demonstrate the efficacy of the proposed approach, an example stabilization problem for a power system comprising three generators and one on-load tap changing transformer is considered.     

离散线性多输入系统的切换反馈镇定

New idea of stabilization for discrete linear multiple-input system is proposed based on switching technique and single-input control. The system discussed here denotes coupled singleinput objects to be controlled. The central processing unit chooses an object at each discrete instant according to periodic switching strategy and controls it by local state feedback. Stabilization of a multiple-input system is turned into stabilization of single-input systems under periodic switching strategy, which is easy to be realized in practice. On the other hand, only one central processing unit can realize all local controllers, which decreases the cost and increases the usage of the resources.     

Switching Feedback Stabilization for Discrete Linear Multiple-input Systems

New idea of stabilization for discrete linear multiple-input system is proposed based on switching technique and single-input control. The system discussed here denotes coupled single-input objects to be controlled. The central processing unit chooses an object at each discrete instant according to periodic switching strategy and controls it by local state feedback. Stabilization of a multiple-input system is turned into stabilization of single-input systems under periodic switching strategy, which is easy to be realized in practice. On the other hand, only one central processing unit can realize all local controllers, which decreases the cost and increases the usage of the resources.     

Robust Stabilization of Uncertain Networked Control Systems with Data Packet Dropouts

The data packet dropouts phenomenon is usually inevitable when information transmit- ted among communication networks.In this paper,the robust stabilization problem for uncertain networked control systems with data packet dropouts is studied.First,an uncertain discrete-time switching system model is presented to describe these networked control systems.The stability equiv- alence is then proved between this switching system and an uncertain impulsive difference system. Moreover,a sufficient condition is obtained for the asymptotical stability of the nonlinear impulsive difference system.From this condition the robust stabilization problem is dealt with for the uncertain impulsive system.Main results are given in linear matrix inequalities.Finally a numerical example is given to illustrate the theoretical results.     

不确定有损网络控制系统的鲁棒镇定

The data packet dropouts phenomenon is usually inevitable when information transmitted among communication networks. In this paper, the robust stabilization problem for uncertain networked control systems with data packet dropouts is studied. First, an uncertain discrete-time switching system model is presented to describe these networked control systems. The stability equivalence is then proved between this switching system and an uncertain impulsive difference system. Moreover, a sufficient condition is obtained for the asymptotical stability of the nonlinear impulsive difference system. From this condition the robust stabilization problem is dealt with for the uncertain impulsive system. Main results are given in linear matrix inequalities. Finally a numerical example is given to illustrate the theoretical results.