一类时变输入时滞不确定系统的鲁棒控制器设计

针对一类具有时变输入时滞的不确定系统,基于Lyapunov-Krasovskii方法,讨论了该类系统鲁棒控制器的设计问题.在不确定性满足范数有界条件下,给出了时滞相关的鲁棒可镇定充分条件及相应的鲁棒控制器设计方法,利用辅助变量和广义状态证明了闭环系统的渐近稳定性.最后,进行了数值仿真,结果证明了该方法的有效性和优越性.     

参数不确定的单时滞系统基于简化的L-K泛函的稳定性分析

参数不确定和时滞广泛存在于各种实际的控制系统中,而且它们往往是导致系统不稳定或性能下降的原因。本文基于Lyapunov稳定性理论,通过构造简化的Lyapunov-Krasovskii泛函,同时应用线性矩阵不等式(LMI:linearmatrix inequality)方法,研究了参数不确定和单时变时滞系统的鲁棒稳定性问题,并导出了由LMI表示的该类系统的鲁棒稳定性判据,而且,通过这类简化的L-K泛函,在充分利用时滞信息的基础上减少了判据的保守性。最后借助含不确定性扰动的具有单时变时滞的单机-无穷大系统模型,分析了保持鲁棒稳定时系统可承受的最大时滞的界限,数值仿真验证了方法的有效性。     

考虑压电陶瓷不确定性的鲁棒自适应控制

选择信息熵作为判定相似性的工具,在判定数据相似性的基础上选择控制对象等效模型参数。采用简单的一阶惯性模型等效复杂的压电陶瓷模型。考虑实际压电器件的不确定性,在等效模型中,将不确定性视为符合高斯分布的变量。考虑不确定参数的影响,基于线性矩阵不等式(LMI)法的鲁棒镇定,保证系统的鲁棒稳定性。选定控制目标,使用自适应李雅普诺夫(Lyapunov)函数方法设计模型控制器。仿真结果验证控制策略效果良好。     

基于最小衰减率约束的鲁棒模型预测控制

针对鲁棒模型受不确定因素干扰,导致时滞消除所用时间较长、预测控制效果较差的问题,提出基于最小衰减率约束的鲁棒模型预测控制方法。建立鲁棒模型离散输入时滞模型,获取最优输出控制增量,构造Lyapunov函数,迭代优化求解鲁棒模型被预测变量;采用梯度处理方法,修正估计波动幅值和周期误差,得到最小衰减率约束量,设计状态观测器时滞模型,定义状态误差干扰项,构造最小衰减率约束集合,实现鲁棒模型预测控制。实验结果表明,所提方法的预测控制效果较好,能够有效缩短时滞消除所用时间。     

不确定系统鲁棒协方差交叉融合稳态Kalman滤波器

针对带不确定模型参数和噪声方差的线性离散多传感器系统,基于极大极小鲁棒估值原理,该文提出一种鲁棒协方差交叉(CI)融合稳态Kalman滤波器。首先,用引入虚拟噪声补偿不确定模型参数,把模型参数和噪声方差两者不确定的多传感器系统转化为仅噪声方差不确定的系统。其次,应用Lyapunov方程证明局部鲁棒Kalman滤波器的鲁棒性,进而保证CI融合Kalman滤波的鲁棒性,且证明了CI融合器的鲁棒精度高于每个局部滤波器的鲁棒精度。最后,给出一个仿真例子来说明如何搜索不确定参数的鲁棒域,并验证所提出的鲁棒Kalman滤波器的优良性能。     

一类2-D奇异系统的鲁棒稳定性分析

针对一类不确定2-D奇异系统第二类Fornasini-Marchesini(SFM-Ⅱ)模型,在闭环系统边界相容,且无跳跃模的条件下,基于Lyapunov稳定性分析方法,利用线性矩阵不等式(LMI)得到具有不确定参数的二维SFM-Ⅱ系统鲁棒稳定性充分条件,并给出了不确定系统的静态状态反馈控制律,为2-D奇异系统的分析与设计提供了一条有效途径。     

约束滚动时域预测控制的鲁棒稳定性分析

研究了一类约束滚动时域预测控制系统的鲁棒稳定问题。利用性能指标值关于状态量的泰勒展开,对存在模型误差时的鲁棒稳定性进行了分析,给出了闭环系统鲁棒稳定的充分条件及其鲁棒稳定的上界。     

一种静不稳定无人机快速跃升与俯冲机动控制器设计

针对无人机在快速跃升与俯冲机动中存在的气动耦合、操纵耦合与不确定扰动,以及由于静不稳定性而造成的不稳定俯仰力矩等问题,提出了一种新的鲁棒模型参考自适应非线性逆控制器。首先,通过基于状态反馈的非线性逆控制完成多通道之间的解耦;然后,依据解耦后的线性闭环系统设计鲁棒模型参考自适应控制器,其主要作用是对非线性逆误差与不稳定俯仰力矩进行补偿,并对不确定扰动进行抑制,从而保证无人机在整个快速机动飞行中的稳定性。通过非线性仿真验证了该控制方法在快速跃升与俯冲纵向机动控制中的有效性与可靠性,并与典型的鲁棒伺服LQR最优控制器对比,说明了该控制器的解耦性能以及对于不确定扰动的抑制作用。     

车窗防夹的H-/H_∞鲁棒故障诊断算法

针对车窗防夹使用安全方面的需求,以解析模型的故障诊断理论为基础,提出了H-/H_∞性能指标的最优鲁棒故障诊断车窗防夹控制算法。该算法将车窗防夹事件发生时的电机转矩变化率看作故障,通过构建鲁棒故障诊断观测器产生一个残差信号,当车窗防夹发生时残差会显著偏离零值,从而将纯电动轿车车窗防夹检测问题转化为H-/H_∞性能指标的鲁棒故障诊断问题,进而利用线性矩阵不等式LMI的方法来求解。在MATLAB环境下建立了Simulink模型,仿真结果表明了该算法在阈值设计为0.5042的情况下能够在故障发生后0.16s及时的检测出防夹事件,同时对不确定扰动及噪声有较强的鲁棒性。     

鲁棒最小二乘在测位探测器建模中的应用

本文主要讨论了鲁棒最小二乘方法在测位控制器建模中的应用。首先简单介绍了鲁棒最小二乘方法的原理及几何解释;对测位控制器的输入误差的结构进行了估计,然后利用这种误差结构所确定的鲁棒最小二乘方法进行测位控制器建模,生成了模型参数,并对所生成的模型参数进行数字仿真验证和误差适应性测试,分析了各种测试结果,从而证明了在有不确定性扰动因素的情况下,利用鲁棒最小二乘方法建模对提高测位控制器的控制精度是有效而可行     

基于不确定非线性智能电网感知网络控制系统方法研究

针对传统的不确定时滞的鲁棒控制系统不能满足现代电力系统发展的需求,提出一种基于不确定非线性智能电网感知云网络化控制识别方法。使用传统的数据值和基于电力网络到网络系统模型作为电力感知网络到网络模型的电力云网络,控制数据优化使用电源感知网络,而不是利用控制节点的预测值,突破了鲁棒控制的不确定时滞系统的控制效果。运用感知模型中的正向云算法修正加权系数,仿真实验证明,该识别方法能够很好地优化传统的不确定时滞鲁棒控制电力系统,具有良好的适应性和鲁棒控制性,进一步提高了智能电网传感云网络控制的各项性能指标。     

Worst-case performance optimization for robust power control in downlink beamforming

In this paper,¹ we examine the problem of robust power control in a downlink beamforming environment under uncertain channel state information (CSI). We suggest that the method of power control using the lower bounds of signal-to-interference-and-noise ratio (SINR) is too pessimistic and will require significantly higher power in transmission than is necessary in practice. Here, a new robust downlink power control solution based on worst-case performance optimization is developed. Our approach employs the explicit modeling of uncertainties in the downlink channel correlation (DCC) matrices and optimizes the amount of transmission power while guaranteeing the worst-case performance to satisfy the quality of service (QoS) constraints for all users. This optimization problem is non-convex and intractable. In order to arrive at an optimal solution to the problem, we propose an iterative algorithm to find the optimum power allocation and worst-case uncertainty matrices. The iterative algorithm is based on the efficient solving of the worst-case uncertainty matrices once the transmission power is given. This can be done by finding the solutions for two cases: (a) when the uncertainty on the DCC matrices is small, for which a closed-form optimum solution can be obtained and (b) when the uncertainty is substantial, for which the intractable problem is transformed into a convex optimization problem readily solvable by an interior point method. Simulation results show that the proposed robust downlink power control using the approach of worst-case performance optimization converges in a few iterations and reduces the transmission power effectively under imperfect knowledge of the channel condition.     

基于鲁棒稳定的闭环激磁电源幅值回路设计

保证系统鲁棒稳定,同时满足系统性能指标要求始终是控制设计的目标。该文根据转台测角系统对激磁电源稳定性和性能指标的要求,提出了采用H优化控制理论,以鲁棒稳定为基础的闭环激磁电源幅值回路设计的方法,讨论了H控制器的求解过程。经四个转台长期使用验证该设计方法的有效性和合理性,完全满足了高精度转台的需要。     

Gain-scheduled robust control for lateral stability of four-wheel-independent-drive electric vehicles via linear parameter-varying technique

This paper proposes a robust gain-scheduled H_∞ controller for lateral stability control of four-wheel-independent-drive electric vehicles via linear parameter-varying technique. The controller aims at tracking the desired yaw rate and vehicle sideslip angle by controlling the external yaw moment. In the design of controller, uncertain factors such as vehicle mass and tire cornering stiffness in vehicle lateral dynamics are represented via the norm-bounded uncertainty. To address the importance of time-varying longitudinal velocity for vehicle lateral stability control, a linear parameter-varying polytopic vehicle model is built, and the built vehicle model depends affinely on the time-varying longitudinal speed that is described by a polytope with finite vertices. In order to reduce conservative, the hyper-rectangular polytope is replaced by a hyper-trapezoidal polytope. Simultaneously, the quadratic D-stability is also applied to improve the transient response of the closed-loop system. The resulting gain-scheduling state-feedback controller is finally designed, and solved utilizing a set of linear matrix inequalities derived from quadratic H_∞ performance and D-stability. Simulations using Matlab/Simulink-Carsim® are carried out to verify the effectiveness of the proposed controller with a high-fidelity, CarSim®, full-vehicle model. It is found from the results that the robust gain-scheduled H_∞ controller suggested in this paper provides improved vehicle lateral stability, safety and handling performance.     

基于高效MPC的活性污泥水处理系统控制

针对具多胞描述不确定性的污水处理控制系统,基于高效预测控制策略（EMPC）设计保性能的控制器。首先给出变参数活性污泥系统的状态空间模型,根据工况特点将其转化为多胞不确定模型,然后结合二次性能指标,通过在线求解凸规划问题,导出保证系统鲁棒渐近稳定的反馈控制律,最后以污水处理厂的处理能力为例,对设计的控制器进行仿真,结果表明,控制器能够保证系统闭环稳定,具有良好的控制效果。     

基于评价指标的电网数据质量评价系统设计

为提高区域性电网数据质量检测和评价能力,构建区域性电网数据质量健康管理和监控的变量模型,以电网的配电电能质量指标、输出稳定性以及电压波动等为基准变量,采用多角度评价指标分析的方法进行区域性电网数据的可靠性评估和预测,采用关联信息融合的方法信息区域性电网数据质量评价的统计分析,结合回归分析和检验统计方法实现对区域性电网数据质量评价的目标函数构造,实现区域性电网数据质量评价。仿真结果表明,采用该方法进行区域性电网数据质量评价的准确性较高,对电网监测评价体系的构造完整性较强。     

谐波环境下基于时域特性分析的电能质量评估

在谐波环境下,电能质量容易发生畸变,电力系统极其不稳定,该研究采用时域特性分析的方法,构建出改进型的电能质量扰动分析模型.该模型能够提取电能扰动特征量、基波幅值变化特征量和加性扰动特征量等,通过Daubechies小波变换实现信号的放大,并对电能质量进行多角度分析.该研究通过对电能质量特征进行量化分析,及时获取谐波、间...     

Robust DFT-based filtering of pulse-like FM signals corrupted by impulsive noise

Filtering of pulse-like FM signals with varying amplitude corrupted by impulse noise is considered. The robust DFT calculated for overlapped intervals is used for this aim. This technique is proposed in order to decrease amplitude distortion of output signals that can be introduced by the robust DFT calculated within a wide interval including possible zero-output. The proposed algorithm is realized through the following steps. In the first stage, the robust DFT is calculated for the intervals. Filtered signals from the intervals are obtained by applying the standard inverse DFT for the robust DFTs applied to input data. In the second stage, results for different overlapped intervals are combined using the appropriate order statistics. In addition, an algorithm inspired by the intersection of the confidence intervals rule is used for adaptive selection of the interval width in the robust DFT. Algorithm accuracy is tested on numerical examples. Computational complexity analysis is also provided.     

Stability analysis of circuits including BJT differential pairs

In this paper, a necessary and sufficient condition for robust stability of electronic circuits at high frequency, which contain differential pair (emitter–coupled pair), is proposed. In fact, when emitter–coupled pairs are used as one input signal–one output signal, they have uncertainty in their transfer functions at high frequency. Even it is shown that this uncertainty can cause instability in closed loop electronic circuits at high frequency.The uncertainty is modeled as multiplicative perturbation in the transfer function of the differential pair at high frequency. Based on this uncertainty model, a necessary and sufficient condition for robust stability of above electronic circuits at high frequency is presented. This condition guarantees internal stability of the circuit at high frequency with respect to the uncertainty.