Robust observer design for nonlinear uncertain systems with LQ regulators

For a class of uncertain systems with linear nominal dynamics and nonlinear uncertainties, it has been shown (Katayama and Sasaki 1987) that linear quadratic (LQ) state feedback regulators can be used to provide robust asymptotic stability. In this paper, we study the combined observer-controller design problem, based on the linear state feedback regulator proposed by Katayama and Sasaki (1987), so that only output feedback is needed. Both full-order and reduced-order observers are considered. For the full-order observer, we propose an algorithm to synthesize the robust observer gain matrix. It is shown that with the observer it is still possible to achieve robust asymptotic stability. For the reduced-order observer, some conditions are derived to guarantee the robust asymptotic stabilizability of the uncertain systems. The trade-off between the magnitudes of controller and observer gains is clear in our approach. An example is used to illustrate the design process of the robust controller with full-order as well as reduced-order observers.     

Valence Distribution in ATxV6-xO11 Compounds

1-IntroductionAVoOll(A,Alkalineoralkalineearthmetal)-typecompoundsaretheonlyphaseswhichshowferromag-neticbehaviorandmetallicconductivityamongvar-iousVs+~V`+mixedvalenceoxidesI1~3].Tohaveagoodunderstandingofthestructure-propertyre-lationship,manypapershavebeenpublishedtore-vealthecrystalstructuresofthesecompoundsinthelatesty6ars.DeRoyetal.l4]determinedcrystalstructureofNaV6O11forthefirsttimewithspacegroupP-62c.Kankeetal.l5lstudiedthecrystalstructuresofSrV6O11,SrTi.V6-.o11(o相似文献   

Solution of variational problems using the Fourier series operational matrix

There are many functions having the property of orthogonality. Among them are Walsh functions, block-pulse functions, Chebyshev functions and Legendre functions. Recently, many scholars and researchers made new approaches to solving variational problems via orthogonal functions. This paper suggests a more simple and powerful orthogonal method—the Fourier series operational matrix for integration—which is derived and used to solve a variational problem.     

Robust stability of linear perturbed discrete systems with saturating actuators

This paper is concerned with the robust stability conditions for linear perturbed systems with saturating actuators in the discrete-time case. Both non-linear and linear perturbations are considered. Two types of controller, a state feedback and a dynamic controller, are introduced to guarantee asymptotic stability of the perturbed system.     

工业工程课程的最新沿革

简要回顾了传统工业工程课程的发展历史,分析了传统工业工程课程的五大局限。之后,根据当代产业的特点和发展需求,以及工业工程学科本身发展的需要,提出了具有现代化活力的工业工程新课程。新课程具有六大特点,其目的是培养学生成为符合现代生产和制造特点的工业工程师。     

Adaptive non-linear Bayesian estimation for bounded-noise systems†

An adaptive non-linear filtering algorithm is developed for handling linear, time-invariant, discrete, dynamical systems with bounded input and measurement noise disturbances. The new result yields the conditional-mean state estimate by combining the Bayesian decision rule, a reachable set concept and a technique of approximating probability density functions by their moments. The adaptive feature is needed because only the input noise bounds, rather than the complete input density function, are assumed to be known. Numerical comparisons on a second-order system are presented to demonstrate that the non-linear filtering algorithm adapts itself to yield considerably more accurate results than those obtained by applying the best linear filter.     

Fragile video watermarking technique by motion field embedding with rate-distortion minimization

In this paper, we proposed a fragile video watermarking technique to authenticate the H.264 video content. Our watermark information is embedded in motion vectors as which have strong fragile nature. The proposed method finds out the best locations of motion vectors to embed the information to achieve the fragility, where are based on the statistical analysis of the motion vector by the H.264/AVC rate-distortion cost function. This scheme does not require the original video sequence for watermark detection. Experimental results show that the proposed watermarking technique can keep the perceptual quality at best effort and still has good fragility.     

A semantic web methodology for situation-aware curative food service recommendation system

Recently curative food is becoming more popular, as more people realize its benefits. Based on the theory of Chinese medicine, food itself is medicine. The curative food which is an ideal nutritious food can help to loss weight, increase immunity and is also good for curative effects in patients. In this paper, we propose a new Curative Food Service （CFS） recommendation system, the designed Situation-aware Curative Food Service Recommendation System （SCFSRS）, which provides the cooperation web-based platform for all related Mobile Users （MUs） and Curative Food Service Providers （CFSPs）, could strengthen the ability of CFS suggestion. SCFSRS is a five-tier system composed of the MUs, UDDI Registries （UDDIRs）, CFSPs, Curative Food Services Server （CFSS）, and Database Server （DS）.     

基于混合业务的OFDMA系统资源分配

针对存在混合业务的OFDMA系统的子载波和功率分配问题,提出了一种基于折衷因子的次优资源分配算法,在系统总发送功率的限制下使得系统的吞吐量最大,同时保证实时业务用户的QoS要求和非实时业务用户资源分配的比例公平.该算法将自适应资源分配与自适应调制相结合,并加入了比特调整和优化处理,对实时业务用户和非实时业务用户间的资源利用进行了有效的折衷.分析和仿真结果表明,SRATF算法在不增加复杂度的前提下减少了运行时间,保证了非实时业务用户间的公平性.     

理想电网条件下双馈风力发电系统低电压穿越技术的控制策略研究

随着风电在电网所占比例的不断增大,提高风机在故障条件下的不间断运行能力越来越重要。通过分析交流励磁变速恒频双馈风机的运行特点,建立双馈风力发电系统的并网数学模型;针对电网电压小幅对称跌落,在不增加硬件成本的基础上,改进传统双馈发电机矢量控制策略,加入前馈补偿项来抑制电压小幅跌落时转子中的过电流,提高双馈风力发电系统的低压穿越能力。在MATLAB/SIMULINK中验证控制策略的合理性,为以后深入研究双馈风力发电系统提供了基础。