Robust fault estimation based on learning observer for Takagi-Sugeno fuzzy systems with interval time-varying delay

This paper studies the problem of robust fault estimation for a class of Takagi-Sugeno(T-S) fuzzy systems which subject to interval time-varying delay, external disturbance, and actuator fault. The designed learning observer can achieve simultaneous estimation of system state and time-varying or constant actuator fault. Then, we construct a new Lyapunov-Krasovskii functional including the information of the lower and upper delay bounds; compared with the time-varying delay, the interval time-varying delay is the less conservative form. Furthermore, one less conservative delay-dependent condition for the existence of learning observer is given in terms of linear matrix inequalities. In addition, the results for the systems with interval time-varying delay are simplified when the delay is not concluded. Finally, simulation results of two examples are presented to show the effectiveness of the proposed method.     

Nonlinear observer design for two-time-scale systems

A two-time-scale system involves both fast and slow dynamics. This article studies observer design for general nonlinear two-time-scale systems and presents two alternative nonlinear observer design approaches, one full-order and one reduced-order. The full-order observer is designed by following a scheme to systematically select design parameters, so that the fast and slow observer dynamics are assigned to estimate the corresponding system modes. The reduced-order observer is derived based on a lower dimensional model to reconstruct the slow states, along with the algebraic slow-motion invariant manifold function to reconstruct the fast states. Through an error analysis, it is shown that the reduced-order observer is capable of providing accurate estimation of the states for the detailed system with an exponentially decaying estimation error. In the last part of the article, the two proposed observers are designed for an anaerobic digestion process, as an illustrative example to evaluate their performance and convergence properties.     

A coupled thermo-chemo-mechanical reduced-order multiscale model for predicting process-induced distortions,residual stresses,and strength

We study residual stresses and part distortion induced by a manufacturing process of a polymer matrix composite and its effect on the component strength. Unlike most of the thermo-chemo-mechanical models in the literature where governing multiphysics equations are directly formulated on the macroscale, we present a multiscale-multiphysics approach. To address the enormous computational complexity involved, a reduced-order homogenization was originally developed for a single physics problem is employed. The proposed reduced-order two-scale thermo-chemo-mechanical model has been validated for predicting part distortion beam strength in three-point bending test. It is shown that while macroscopic stresses are relatively low, and therefore often ignored in practice, stresses at the scale of microconstituents are significant and may have an effect on the overall composite component strength.     

A computer method for formal linearization of nonlinear systems by the discrete fourier expansion and its applications

This paper proposes a numerical computer method for formal linearization of nonlinear systems by using the discrete Fourier expansion. A nonlinear system is described by a system of nonlinear ordinary differential equations. A linearizing function is given by a sequence of trigonometric functions. The nonlinear terms of the differential equations are expanded into finite sums of trigonometric functions by the method of the discrete Fourier expansion. As a result, a formal linear system is derived from the given nonlinear system. A computer algorithm of the linearization is acquired and numerical computation is easily carried out with the aid of computers. Further, as the application of the linearization, both a nonlinear observer and a nonlinear filter are synthesized in this paper. Examples show that the accuracy of the method is improved as the order of the trigonometric functions increases.     

奇异系统的一类新型观测器

本文利用非线性跟踪－微分器，设计出了线性时不变奇异系统的观测器。这里仅要求原系统Ｒ－能检，对原系统的控制输入，仅只要求它有界可积，从而很大地减弱了设计条件。     

多输入多输出线性控制系统的简单极点配置算法

本文给出了对多输入多输出系统进行极点配置的算法。按照本文的结论，任何多输入多输出线性控制系统都可以象单输入单输出线性系统那样进行闭环系统及状态观测器的极点配置。     

Further assessment of the HEXACO Personality Inventory: Two new facet scales and an observer report form.

The HEXACO Personality Inventory (HEXACO-PI) operationalizes the six factors obtained from lexical studies of personality structure in several languages. In this study, psychometric properties of the HEXACO-PI were assessed using a community adult sample and also using observer reports, thereby extending the previous investigation relying only on self-reports from a college student sample. In addition to examining the original 24 HEXACO-PI facet scales, the authors also examined two new facet scales--Altruism versus Antagonism and Negative Self-Evaluation--that assess constructs located interstitially among the factors of the HEXACO space. The HEXACO-PI again showed favorable psychometric properties in terms of reliability and factor structure and also showed high levels of self/observer agreement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

间接测量装置的一种设计方法

本分析用于间接测量的观测器优化极点配置及其结构参数的设计方法，给出设计范例和观测器的优化参考模型。     

基于状态空间方法的系统零极点校正

状态空间方法很早就应用于系统校正，但当被控制对象包含有零点时，其应用就比较困难。本文提出以优化闭环传递函数为参考模型，由观测器与补偿器构成系统的反馈校正器可以比较方便地解决这个问题。     

Analysis on Biological Stability and Influencing Factors of Northern Living District Water Distribution System

多柔性连杆机械臂的自抗扰控制

刘延芳^1,2, 刘宏¹,孟瑶³

（1. 哈尔滨工业大学 机器人技术与系统国家重点实验室,哈尔滨 150001;

2.哈尔滨工业大学 航天学院,哈尔滨 150001;

3.上海宇航系统工程研究所,上海 201109）

创新点说明

将自抗扰控制应用到多柔性连杆机械臂的运动控制上。

研究目的

主要解决多柔性连杆机械臂的运动控制问题,在转角运动控制的同时,抑制柔性臂杆的振动。

研究方法

首先基于时标分离,将系统分解为快时标系统和慢时标系统：快时标系统为内环,采用最优二次型控制器,实现臂杆振动的快速抑制;慢时标系统为外环,采用自抗扰控制,抑制系统外界干扰、未建模动态等内外扰动,实现转角位置的精确控制。

结 果

采用自抗扰控制器可以显著提高转角控制精度,并抑制臂杆的振动,其中自抗扰控制器中采用飞线性PD控制器时,优势更为明显。

结 论

自抗扰控制器在应用于多柔性连杆机械臂的运动控制中具有一定的优势,可以进行工程推广。

关键词：多柔性连杆机械臂;自抗扰控制;飞线性比例微分控制器;跟踪微分器;状态扩张观测器