Passive fuzzy controller design for nonlinear systems with multiplicative noises

This paper proposes a passive fuzzy controller design methodology for nonlinear system with multiplicative noises. Applying the Itô's formula and the sense of mean square, the sufficient conditions are developed to analyze the stability and to design the controller for stochastic nonlinear systems which are represented by the Takagi-Sugeno (T-S) fuzzy models. The sufficient conditions derived in this paper belong to the Linear Matrix Inequality (LMI) forms which can be solved by the convex optimal programming algorithm. Besides, the passivity theory is applied to discuss the effect of external disturbance on system. Finally, some numerical simulation examples are provided to demonstrate the applications of the proposed fuzzy controller design technique.     

Control systems approach to the sample inverse covariance matrix

A new method is proposed for finding the inverse of the covariance (or correlation) matrix. The technique is based on a previous method known as automatic variance control. The technique naturally gives rise to the inverse due to the properties of negative feedback itself rather than by traditional invertion methods. The method can be applied to the non-stationary problem and can form part of a recursive parameter estimation scheme.     

Matrix solution bounds of the continuous Lyapunov equation by using a bilinear transformation

By using a bilinear transformation and some linear algebraic techniques, new matrix bounds of the solution of the continuous algebraic Lyapunov equation (CALE) are derived in this paper. Comparing to existing works, these obtained matrix bounds are less restrictive and are easy to be calculated. A numerical example is also given to demonstrate the merits of the present results.     

State estimation for jump markov nonlinear systems of unknown measurement data covariance

For state estimation of high accuracy, prior knowledge of measurement noise is necessary. In this paper, a method for solving the joint state estimation problem of jump Markov nonlinear systems (JMNSs) without knowing the measurement noise covariance is developed. By using the Inverse-Gamma distribution to describe the dynamics of measurement noise covariance, the joint conditional posterior distribution of the state variable and measurement noise covariance is approximated by a product of separable variational Bayesian (VB) marginals. In the newly constructed approach, the interacting multiple model (IMM) algorithm, as well as the particle-based approximation strategy, is employed to handle the computationally intractable problem and the nonlinear characteristics of systems, respectively. An interesting feature of the proposed method is that the distribution of states is spanned by a set of particles with weights, while the counterpart of measurement noise covariance is obtained analytically. Moreover, the number of particles is fixed under each mode, indicating a reasonable computational cost. Simulation results based on a numerical example and a tunnel diode circuit (TDC) system are presented to demonstrate that the proposed method can estimate the measurement noise covariance well and provide satisfied state estimation when the statistics of the measurement are unavailable.     

On the continuous time-varying JLQG

In this paper, the optimal control law for the continuous infinite time-varying stochastic control system with jumps and quadratic cost is found under the assumption that the coefficient have limits as time tends to infinity and the boundary system is absolutely observable and stabilizable. In addition, the asymptotic properties of the solution of the differential Riccati equations for continuous time Markovian jump linear quadratic control problem with time-varying coefficient are established.     

On linear generalized neutral differential delay systems

In this paper, the class of linear generalized neutral differential delay systems with time-invariant coefficients is studied. These kinds of systems are inherent in many physical and engineering phenomena. Using the matrix pencil theory, we decompose it into five subsystems, whose solutions are obtained. Moreover, the form of the initial function is given, so the corresponding initial value problem is uniquely solvable.     

On the excitability of a class of positive continuous time-delay systems

This article is on the excitability of positive linear time-invariant systems subject to internal point delays. It is proved that excitability independent of delay is guaranteed if an auxiliary delay-free system is excitable. Necessary and sufficient conditions for excitability and transparency independent of the delay size are formulated in terms of the parameterization of the dynamics and control matrices. Some particular results are also given for the properties being dependent on the size of the point delay and for any possible finite values of the delay. The same formulation is given in parallel in terms of strict positivity of a matrix of an associate system obtained from the influence graph of the original system. The excitability and transparency properties are both testable through simple algebraic tests involving a moderate computational effort that is directly related to the system's order.     

Robust stable pole-placement-based adaptive control of continuous linear systems with two parametrical estimation schemes

This paper deals with the pole-placement-type robust adaptive control of continuous linear systems in the presence of bounded noise and a common class of unmodeled dynamics provided that two estimation schemes are used in parallel. Both estimation schemes are introduced in order to minimize the plant identification error by selecting, as plant parameter estimates, a convex combination of both parameter estimates which leads to the selection of one of the estimation schemes, via a switching rule, on time intervals of at least a minimum prefixed residence duration. The weights of the individual parameter vector estimates are provided at each time by an optimization or suboptimization scheme for a quadratic loss function of the possibly filtered tracking error and/or control input. The robust stability of the overall adaptive scheme is ensured by an adaptation relative dead zone which takes into account the contribution of the unmodeled dynamics and bounded noise. The basic results are derived for two different estimation strategies which have either a shared regressor with the plant or individual regressors for the input contribution and its contributed derivatives. In this second case, the plant input is obtained from a similar convex combination rule as the one used for the estimators in the first approach. An extension of the basic strategies is also pointed out including a combined use of the (sub) optimization scheme with a supervisor of past measures for the on-line calculation of the estimator weights in the convex combination. Finally, the extension of the scheme for the use of any number of parametrical estimators is focused on.     

基于区域协方差矩阵的模板更新方法分析与比较

在目标跟踪算法中,目标特征描述子和模板更新策略都是跟踪成败的关键。本文在选用区域协方差矩阵描述子的基础上,结合粒子滤波器算法,并且采用两种常用的模板更新方法,分别对商场通道监控视频序列中的行人进行了跟踪仿真实验。通过仿真分析并比较不同模板更新方法条件下的跟踪性能,从而在不同情况下选择合适的模板更新方法,以得到更精确的跟踪结果。     

A note on the coherence-based signal-to-noise ratio estimation in systems with periodic inputs

Coherence plays a very important role in linear systems analysis, since, in addition to quantify the similarity between signals, it is related to other quantities of interest, such as the signal-to-noise ratio (SNR). The sampling distribution of coherence estimates between Gaussian signals is well established, and hence, in this particular case, the statistics of SNR can be readily found if it is calculated from coherence estimates. However, in some applications, one of the signals is periodic, leading to a different coherence sampling distribution, which has been recently investigated. This work aims at developing analytical expressions for bias, variance and the probability density function of coherence-based SNR estimates under this particular assumption. Routines for obtaining this latter as well as critical values of the estimates are also provided.     

高校体育教育发展中引入拓展训练的必要性

拓展训练作为一种新兴课程,近几年逐渐介入到高等院校的体育课程中,引起了教学领域的普遍关注。社会的发展对大学生整体素质提出了新的要求,大学教育必须采用多元化的教育方法,拓展训练,以一种全新的教育模式,对推动传统教育方式的改革,对当代高校体育教育的改革、素质教育的指导思想,对培养符合时代要求的高素质人才,对大学生整体素质的提高具有重要意义。本文对如何在高校教学发展建设中引入拓展训练的必要性及拓展训练所起到的作用意义进行简要的说明分析。     

Decentralized state estimation for the control of network systems

The paper proposes a decentralized state estimation method for the control of network systems, where a cooperative objective has to be achieved. The nodes of the network are partitioned into independent nodes, providing the control inputs, and dependent nodes, controlled by local interaction laws. The proposed state estimation algorithm allows the independent nodes to estimate the state of the dependent nodes in a completely decentralized way. To do that, it is necessary for each independent node of the network to estimate the control input components computed by the other independent nodes, without requiring communication among the independent nodes. The decentralized state estimator, including an input estimator, is developed and the convergence properties are studied. Simulation results show the effectiveness of the proposed approach.     

Control structure design of networked control systems based on maximum allowable delay bounds

In this work, we present a control structure based on the maximum allowable delay bound of networked control systems that takes the network-induced delay into account. Control structure design deals with the structural decisions of the control system including where to place the controllers and how to harmonize them. We construct a hierarchical control structure that consists of a main controller and a local closed-loop system consisting of a family of control configurations. Based on the maximum allowable delay bound for each local configuration, the local supervisor orchestrates switching between the constituent configurations. The stability condition is derived based on common Lyapunov function technique. An example is presented to demonstrated the efficacy of the proposed approach.     

On the uncertain variable structure systems with bounded controllers

In this paper, we propose a method to estimate the asymptotic stability region (ASR) of uncertain variable structure systems with bounded controllers. Using linear matrix inequalities (LMIs) we estimate the ASR and we show the exponential stability of the closed-loop control system in the estimated ASR. We also give simple LMI-based algorithms for estimating the ASR and designing a switching surface which will make the estimated ASR big. Finally, we give numerical examples in order to show that our method can be better than the previous results for a certain class of uncertain variable structure systems with bounded controllers.     

论企业持续技术创新的结构

企业持续技术创新是技术创新型企业的独特的组织行为 ,是由技术家族创新和战略技术创新两个阶段组成的多次循环往复的过程。本文分析了技术家族创新、战略技术创新和技术创新型企业的结构。     

On the analysis of discontinuous systems

An effective procedure, employing an operational approach, is demonstrated for the analysis of constant parameter continuous systems with multiple lumped parameter attachments and concentrated forces. Convenience of the method and of the form in which the results are obtained are evaluated in comparison with other applicable methods. Systems with piecewise constant parameters are also investigated. The desirability of obtaining a complete closed-form steady-state solution and various methods of obtaining it are examined. Finally, an example is treated which illustrates the application of the operational method to system with jump discontinuities in deflection and slope.     

一种CMMB系统信道估计改进算法的研究

针对CMMB系统中接收信号因受传输环境的大、小尺度衰落、多普勒衰落影响,通过最小二乘信道估计和低密度奇偶校验码LDPC（Low Density Parity Check Code）译码结合的算法在接收端对信号进行接收处理,实验仿真表明,该算法可以达到与经典算法的性能相接近效果的同时大量减少了系统的复杂度。