迟滞非线性系统的建模与控制

介绍了对不平滑、多映射迟滞非线性系统的研究成果,重点阐述了迟滞建模与控制器设计的研究现状.详细地分析比较了Preisach模型和线性迟滞模型优缺点.在控制器设计方法方面,比较了常用的两类基于逆模型补偿方案的特点、差别和适应范围,并扼要论述了其他控制方案.最后,对迟滞研究中仍需解决的问题和未来发展方向进行了探讨.  

基于MATLAB的并联有源电力滤波系统的仿真研究

本文系统分析了有源电力滤波系统的工作原理 ,系统结构 ,控制方法等 ,并以MATLAB为仿真工具 ,对三相有源电力滤波系统进行建模及仿真分析。不同于传统的模拟滞环比较器 ,这里采用基于DSP软件控制的滞环比较方式控制补偿电流的产生 ,实现简单。在此基础上 ,着重分析输入电感 ,采样频率以及直流侧电压对补偿效果的影响。仿真结果表明 ,若参数选取适当 ,该系统具有较好的谐波补偿效果。  

State-space analysis and identification for a class of hysteretic systems

In this paper we present results on the twin subjects of system analysis and system identification for a class of state-space realizable dynamic systems under the influence of hysteresis. The class of systems in question consists of models in the form of a linear time-invariant dynamic system in series with a differential model of hysteresis. It will be demonstrated that under fairly light constraints on the differential model of hysteresis, it is possible to design a series of experiments leading towards the identification of the full state-space realization. The approach is tested successfully on a high-precision mechanical translation system affected by hysteresis.  

基于新的阈值化方法的背景减法改进

首先将一种新的基于颜色空间模型的阈值化方法用于背景减法中. 该阈值化方法利用每个像素的颜色畸变和亮度畸变检测出场景中所有的运动, 其中像素的颜色畸变检测考虑了颜色向量所处的空间位置; 同时该阈值化方法在一定程度上抑制了运动阴影的影响. 其次, 将一种双阈值化方法用于背景减法中, 实现了复杂场景下前景目标的提取. 通过VSSN 05和PETS 2006测试视频的实验, 验证了本文提出算法的有效性.  

A limit cycle approach for the parametric identification of hysteretic systems

This paper deals with the parametric identification of the Bouc–Wen model for smooth hysteresis. The interest of the problem stems from the fact that the Bouc–Wen model has been used experimentally to represent various hysteretic systems during the last few years. However, identifying the parameters of this model is not a trivial task due to the nonlinearity of the model. In the current literature, most methods devoted to the parametric identification of the Bouc–Wen model rely mainly on numerical simulations, and do not offer, to a large extent, a rigorous proof of the convergence of the estimated parameters to the true ones. This paper presents a new identification method that guarantees the exact determination of the parameters in the absence of perturbations. It is also shown that this method is robust with respect to a class of disturbances of practical interest. The applicability of this method is illustrated by means of experiments.  

Modeling and control of hysteresis in magnetostrictive actuators

A novel dynamic model is proposed for the hysteresis in magnetostrictive actuators by coupling a Preisach operator to an ordinary differential equation, and a parameter identification method is described. An efficient inversion algorithm for a class of Preisach operators with piecewise uniform density functions is then introduced, based upon which an inverse control scheme for the dynamic hysteresis model is presented. Finally the inversion error is quantified and l₁ control theory is applied to improve the robustness of inverse compensation. Simulation and experimental results based on a Terfenol-D actuator are provided.  

气动肌肉主动悬架系统的仿真模型与分析

以气动肌肉作为新型执行器，创建基于1／4悬架模型的汽车主动悬架系统。并运用Matlab中的Simulink模块库建立此系统的仿真模型，着重讨论仿真建模以及仿真过程中所遇到的困难，诸如气动肌肉迟滞特性的实现、高频分量对仿真结果的影响等问题。经对系统机理模型的适当变换处理，促进了仿真系统的稳定。利用获得的仿真模型对气动肌肉主动悬架系统的动态特性进行仿真研究，结果分析表明所建立的仿真模型已能满足实用的气动肌肉主动悬架系统的研究需要。  

Discontinuities and hysteresis in quantized average consensus

We consider continuous-time average consensus dynamics in which the agents’ states are communicated through uniform quantizers. Solutions to the resulting system are defined in the Krasowskii sense and are proven to converge to conditions of “practical consensus”. To cope with undesired chattering phenomena we introduce a hysteretic quantizer, and we study the convergence properties of the resulting dynamics by a hybrid system approach.  

球－杆系统的非线性问题

球－杆系统真正的问题并不是大行程下的非线性现象, 而是平衡点上的自振荡问题. 分析指出自振荡是由于球在滚动时存在一种滞环特性而引起的. 提出了一种极点配置的方法来避免自振荡. 仿真和实验验证了这一判断. 所采取的稳定措施也是正确的.