基于迭代无迹H_∞滤波的移动机器人SLAM

为缓解移动机器人同步定位与构图(Simultaneous Localization and Mapping,SLAM)在恶劣噪声干扰下存在估计精度低、不一致及鲁棒性差的问题,提出一种新颖的基于迭代无迹H_∞滤波的SLAM算法。所提算法将无迹变换融入到扩展H_∞滤波中,以此估计系统状态均值和协方差,无需推导Jacobian矩阵,避免了线性化误差积累,增强了算法的数值稳定性;此外,通过迭代更新方式,利用观测信息不断校正系统状态均值和协方差,进一步减小估计误差。在仿真实验中,在不同环境和不同噪声下对比分析所提算法、EKF-SLAM、UKF-SLAM及CEHF-SLAM。结果表明所提算法在不同恶劣噪声干扰下依然能保持高的估计精度和强鲁棒性,并能适应不同的环境,是一种有效且可行的SLAM算法。

关于组合系统的分散H_∞控制

本文考虑线性组合系统的分散状态反馈Ｈ∞控制问题．以Ｒｉｃｃａｔｉ－ｌｉｋｅ方程半正定解的术语给出了一个使得给定的组合系统稳定并且对于扰抑制保证一个Ｈ∞界限制的分散状态反馈控制设计．对具有对称循环结构的组合系统，得到一个简单的分散控制设计程序．作为一个应用，对一族线性系统的同时Ｈ∞控制问题的可解性导出了一个充分条件．

Robust reliable H_∞ control for discrete-time Markov jump linear systems with actuator failures

The robust reliable H∞ control problem for discrete-time Markovian jump systems with actuator failures is studied. A more practical model of actuator failures than outage is considered. Based on the state feedback method, the resulting closed-loop systems are reliable in that they remain robust stochastically stable and satisfy a certain level of H∞ disturbance attenuation not only when all actuators are operational, but also in case of some actuator failures, The solvability condition of controllers can be equivalent to a feasibility problem of coupled linear matrix inequalities （LMIs）. A numerical example is also given to illustrate the design procedures and their effectiveness.

广义时滞系统的鲁棒同时H_∞控制

讨论不确定广义系统时滞相关的鲁棒同时H_∞控制问题。首先,通过引入Lyqpunov-Krasovskii泛函以线性矩阵不等式(LMI)形式给出时滞相关的新有界实引理,使得系统正则、无脉冲、稳定且具有H_∞性能。其次,在有界实引理基础上得到广义闭环系统的同时H_∞控制器存在的时滞相关的充分条件。进一步推广到不确定广义时滞闭环系统中,并给出鲁棒同时H_∞控制器的的设计方法。控制器可由一组线性矩阵不等式(LMI)求解得到,避免了系统中矩阵的分解。最后,由仿真算例说明该设计方法的有效性。

H_∞ control for stochastic systems with time-delay

The H∞-control problem of stochastic systems with time-delay is considered. The sufficient conditions are obtained, under which there are always state-feedback control and dynamic output-feedback control so that the resulting closed-loop system is internaly stable and L2 input-output stable in the sense of expectation. Furthermore, the explicit formulas of both kinds of controls are derived. An example is included to illustrate the correctness of theoretic results.

Non-isothermal kinetic analysis of thermal dehydration of La_2(CO_3)_3·3.4H_2O in air

The single phase La2（CO3）3·3.4H2 O was synthesized by hydrothermal method. The thermal decomposition and intermediates and final solid products of La2（CO3）3·3.4H2O from 30 to 1000 °C were characterized by XRD, FTIR and DTA-TG. The kinetics of dehydration of La2（CO3）3·3.4H2O in the temperature range of 30-366 °C was investigated under non-isothermal conditions. Flynn-Wall-Ozawa and Friedman isoconversion methods were used to calculate the activation energy and analyze the reaction steps; multivariate non-linear regression program was applied to determine the most probable mechanism and the kinetic parameters. The results show that the thermal dehydration of La2（CO3）3·3.4H2O is a kind of three-step competitive reaction, and controlled by an n-order initial reaction followed by n-order competitive reaction（FnFnFn model）. The activation energy matching with the most probable model is close to value obtained by Friedman method. The fitting curves match the original TG-DTG curves very well.

一种适合于H·264实时视频传输的新型加密方案

H.264是由ITU-T和ISO/IEC联合制定的最新视频编码标准,其安全加密技术正成为研究的热点.文章通过研究适合于H.264加密的侯选域,提出了一种加密与压缩相结合的新型视频加密方案,该方案包括崭新的CAVLC(基于上下文的自适应变长编码)与QTC(量化变换系数)加密同步,预测模式置乱和运动矢量置乱.理论分析和实验结果表明,此方案速度快,安全性高,传输误码鲁棒性较强,并对压缩比影响小.

K比例H点标准加入吸光光度法同时测定矿样中铌和钽

在盐酸介质中,水杨基荧光酮-氯化十六烷基吡啶体系虽然能分别和铌、钽发生灵敏的络合反应,但所形成的三元胶束络合物的光谱严重重叠,不适合同时测定铌和钽。文章采用K比例H点标准加入分光光度法,结合Origin 7.5软件,选择最佳波长对,探讨了在不经化学分离的情况下,同时测定矿样中铌和钽的方法。结果表明,K比例H点标准加入法很好地解决了铌和钽的光谱干扰问题,得到了待测物的浓度,还对干扰物质的浓度进行估算。在最佳试验条件下,铌和钽的线性范围分别为（0.4-5.8）×10^-5g/L、（0.4-11.2）×10^-5g/L,方法检出限分别为0.28μg/L、0.22μg/L,测定精密度分别为0.54%-0.88%、0.88%-1.52%。方法用于样品中铌和钽的同时测定,测定值与参考值相符。

基于CEH∞ F的移动机器人SLAM算法研究

针对移动机器人同时定位与地图创建(SLAM)面对噪声干扰时估计精度低、鲁棒性差的缺点,提出一种基于容积扩展H∞滤波(CEH∞F)的SLAM算法。首先,通过线性误差传播特性将容积变换嵌入到扩展H∞滤波框架中,利用得到的CEH∞F计算SLAM条件转移概率密度,避免雅克比矩阵的计算和线性化误差积累的同时增强了算法的鲁棒性;另外,在每次迭代中更新调节因子γ,将噪声干扰到估计误差最大能量增益控制在较小范围内,进一步增强算法鲁棒性。实验部分将所提算法与扩展卡尔曼滤波SLAM(EKF-SLAM)、无迹卡尔曼滤波SLAM(UKF-SLAM)、容积卡尔曼滤波SLAM(CKF-SLAM)在不同噪声环境下进行了对比。结果表明,CEH∞F-SLAM算法具有良好的稳定性与精度,是一种有效的SLAM算法。

基于同时平衡原理的Au-I^--H_2O系热力学分析

采用同时平衡原理对Au-I--H2O系的浸金热力学进行分析,分别研究溶液与固体Au以及Au I沉淀与固体Au平衡时的φ-p H关系、Au I存在条件和溶液中含金组分的变化规律。结果表明:随着溶液中含金组分的总浓度cT(Au)的降低或含碘组分的总浓度cT(I-)的增加,还原电位φsol/Au迅速降低,Au3+/Au2O3的平衡p H值增大,非常有利于金的碘化浸出;随着溶液中cT(I-)逐渐增加,出现Au I沉淀且其沉淀量呈先增大后减小的趋势;在cT(Au)为1×10-4 mol/L的条件下,当溶液中cT(I-)浓度大于0.0021 mol/L时,可避免Au I沉淀的生成,金主要以Au I2-络合离子形式存在。Au-I--H2O系的浸金热力学分析为金的高效碘化浸出提供了理论依据。

K比例H点标准加入法同时测定锌与镉

锌与镉化学性质相似,常常共存于同一试样中,与试剂 4- (2-吡啶偶氮 )间苯二酚(PAR)发生显色反应,其吸收光谱相互重叠.用K比例H点标准加入法结合分光光度法对该混合体系进行了研究,建立了不经分离,同时测定锌、镉的方法,结果满意.

K比例H点标准加入光度法同时测定铝和铜

在pH值为6.0的六次甲基四胺-HC l缓冲溶液中,Cu2+和A l3+可分别与铬天青S、溴代十六烷基吡啶形成绿色三元络合物。研究了两种络和物的形成条件,并优选出试验条件,提出了用K比例H点标准加入法同时测定Cu2+和A l3+的新方法,该方法用于水样中Cu2+和A l3+的同时测定,取得了满意的结果。

2-(5-硝基2-吡啶偶氮)-H酸光度法同时测定铜和镍

报道了新显色剂 2 ( 5 硝基 2 吡啶偶氮 ) H酸 (简称 5 NO2 PAH)同时测定铜、镍的显色体系 ,系统的研究了该试剂与铜、镍显色的适宜条件及共存离子的影响。结果表明 :在 pH8 5～ 10 0范围内 ,铜、镍与试剂形成稳定的络合物 ,表观摩尔吸光系数分别为εCu=4 68× 10 4 ,εNi=1 0 7× 10 5,铜的浓度在 0～ 12 μg/10mL、镍的浓度在 0～ 5 μg/10mL范围内遵守比尔定律。方法用于样品测定 ,结果满意。

中央企业A+H同步IPO模式分析

虽然A+H同步IPO模式目前尚不具备常态化操作的条件,但相对于早期的先H后A,对于尚未在香港上市的中央企业而言至少具备7大优点:一是两地同时上市,有利于扩大新股发行影响,提高资金募集效率;二是可以避开其中某一个市场出现不稳定市况的影响,降低首次公开发行的风险;三是能够使企业获得更优的发行价,而此前香港市场的发行市盈率和二级市场市盈率都要低于内地市场,同时以A+H同步IPO,企业投资者基础更加广泛,这会有利于公司价值得到深入挖掘;四是可以使上市公司充分利用国际和国内两个资本市场的优势,尤其是利用香港市场监管国际化的优势提升企业市场化和规范化经营;五是同步发行A股、H股将发行影响扩大到全球范围,能极大地提升公司的市场形象和国际知名度;六是对于企业再融资也带来便利条件;七是上市前期工作也可以相互利用,募集资金到位更加及时。此外,中央企业A+H同步整体上市对于资本市场而言,也具有许多优点。

Simultaneous H_2/H_∞ Stabilization for Chemical Reaction Systems Based on Orthogonal Complement Space

This paper presents a simultaneous H2/H∞ stabilization problem for the chemical reaction systems which can be modeled as a finite collection of subsystems. A single dynamic output feedback controller which simultaneously stabilizes the multiple subsystems and captures the mixed H2/H∞ control performance is designed. To ensure that the stability condition, the H2 characterization and the H∞ characterization can be enforced within a unified matrix inequality framework, a novel technique based on orthogonal complement space is developed. Within such a framework, the controller gain is parameterized by the introduction of a common free positive definite matrix, which is independent of the multiple Lyapunov matrices. An iterative linear matrix inequality （ILMI） algorithm using Matlab Yalmip toolbox is established to deal with the proposed framework. Simulation results of a typical chemical reaction system are exploited to show the validity of the proposed methodology.

多输入非线性时滞系统的同时H^∞控制

将单输入无时滞系统的相关结果,推广到多输入非线性时滞系统,设计了一个H^∞状态反馈控制器,用来同时镇定一族多输入非线性时滞系统.引入储能泛函的概念,提出构造时滞系统储能泛函的一种方法,给出同时H^∞状态反馈控制器存在的一个充分条件及其构造公式.

A novel robust approach for SLAM of mobile robot

The task of simultaneous localization and mapping （SLAM） is to build environmental map and locate the position of mobile robot at the same time. FastSLAM 2.0 is one of powerful techniques to solve the SLAM problem. However, there are two obvious limitations in FastSLAM 2.0, one is the linear approximations of nonlinear functions which would cause the filter inconsistent and the other is the ＂particle depletion＂ phenomenon. A kind of PSO ＆ Hjj-based FastSLAM 2.0 algorithm is proposed. For maintaining the estimation accuracy, H~ filter is used instead of EKF for overcoming the inaccuracy caused by the linear approximations of nonlinear functions. The unreasonable proposal distribution of particle greatly influences the pose state estimation of robot. A new sampling strategy based on PSO （particle swarm optimization） is presented to solve the ＂particle depletion＂ phenomenon and improve the accuracy of pose state estimation. The proposed approach overcomes the obvious drawbacks of standard FastSLAM 2.0 algorithm and enhances the robustness and efficiency in the parts of consistency of filter and accuracy of state estimation in SLAM. Simulation results demonstrate the superiority of the proposed approach.

H-infinity control for air-breathing hypersonic vehicle based on online simultaneous policy update algorithm

Purpose–The air-breathing hypersonic vehicle(AHV)includes intricate inherent coupling between the propulsion system and the airframe dynamics,which results in an intractable nonlinear system for the controller design.The purpose of this paper is to propose an H1 control method for AHV based on the online simultaneous policy update algorithm(SPUA).Design/methodology/approach–Initially,the H1 state feedback control problem of the AHV is converted to the problem of solving the Hamilton-Jacobi-Isaacs(HJI)equation,which is notoriously difficult to solve both numerically and analytically.To overcome this difficulty,the online SPUA is introduced to solve the HJI equation without requiring the accurate knowledge of the internal system dynamics.Subsequently,the online SPUA is implemented on the basis of an actor-critic structure,in which neural network(NN)is employed for approximating the cost function and a least-square method is used to calculate the NN weight parameters.Findings–Simulation study on the AHV demonstrates the effectiveness of the proposed H1 control method.Originality/value–The paper presents an interesting method for the H1 state feedback control design problem of the AHV based on online SPUA.

同时蒸馏萃取三七花挥发油成分的气相色谱-质谱分析

目的:测定中药三七花中挥发油成分。方法:采用自制的同时蒸馏萃取装置提取(水蒸气蒸馏,乙醚萃取)云南文山三七花的挥发油成分,然后经气相色谱-质谱联用仪测定,用峰面积归一化法定量。分析条件:HP-5石英毛细管柱(30 m×0.25 mm×0.25 μm),程序升温50—250℃,分流进样,分流比50:1,进样温度250℃,MS检测器。结果:挥发油中共分离出91个成分,鉴定了其中53个化合物,主要为萜烯类及其含氧衍生物(71.15%)。含量较高的是匙叶桉油烯醇(12.19%)、α-古芸烯(6.73%)、双环吉马烯(6.57%)、吉马烯-D(5.26%)、双环榄香烯(3.55%)。结论:本方法提取和测定挥发油高效、适用、准确。

切换系统的同时故障估计与容错控制

当切换系统发生故障时,通常需要依次进行故障诊断和容错控制.为了提高切换系统故障诊断的可靠性和容错控制的及时性,本文提出一种同时故障估计与容错控制方法.针对满足平均驻留时间约束的线性切换系统,首先建立了基于状态观测器的同时故障估计与容错控制器,并将其设计问题转化为了加权H∞性能指标下增广误差系统的多目标求解问题.然后使用平均驻留时间技术和多Lyapunov函数方法设计了故障估计与容错控制器的参数,又通过松弛矩阵方法进一步得到了保守性较低的结果.最后,利用一个例子对本文所提方法进行了仿真,证实了该方法的有效性.