检索结果-南通市图书馆

Widely linear UKF constant modulus algorithm for blind adaptive beamforming

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2017年第3期28卷 413-423页

作者： huaming qian Ke Liu Long Li Linchen qian Junda Ma College of Automation Harbin Engineering University Advanced Signal Processing Lab College of EngineeringTemple University Information Communication Branch State Grid Heilongjiang Electric Power Company Limited School of Computing Beihang University

Based on a uniform linear array, a new widely linear unscented Kalman filter-based constant modulus algorithm (WL-UKF-CMA) for blind adaptive beamforming is proposed. The new algorithm is designed according to the constant modulus criterion and takes full advantage of the noncircular property of the signal of interest (SOI), significantly increasing the output signal-to interference-plus-noise ratio (SINR), enhancing the convergence speed and decreasing the steady-state misadjustment. Since it requires no known training data, the proposed algorithm saves a large amount of the available spectrum. Theoretical analysis and simulation results are presented to demonstrate its superiority over the conventional linear least mean square-based CMA (L-LMS-CMA), the conventional linear recursive least square-based CMA (L-RLS-CMA), WL-LMS-CMA, WL-RLS-CMA and L-UKF-CMA.

关键词： widely linear filtering blind beamforming noncircular signals constant modulus algorithm unscented Kalman filtering

Surface Doping vs.Bulk Doping of Cathode Materials for Lithium-Ion Batteries:A Review

在线全文

学校读者我要写书评

暂无评论

Electrochemical Energy Reviews 2022年第4期5卷 254-285页

作者： huaming qian Haoqi Ren Ying Zhang Xianfeng He Wenbin Li Jingjing Wang Junhua Hu Hong Yang Hirbod Maleki Kheimeh Sari Yu Chen Xifei Li Xi’an Key Laboratory of New Energy Materials and Devices Institute of Advanced Electrochemical Energy and School of Materials Science and EngineeringXi’an University of TechnologyXi’an 710048ShaanxiChina Shaanxi International Joint Research Center of Surface Technology for Energy Storage Materials Xi’an 710048ShaanxiChina Department of Mechanical and Materials Engineering University of Western OntarioLondonOntario N6A 5B9Canada State Center for International Cooperation On Designer Low‑Carbon and Environmental Materials(CDLCEM) Zhengzhou University100 Kexue AvenueZhengzhou 450001China Xi’an Safty Energy Technology Co. LtdXi’an 710005ShaanxiChina

To address the capacity degradation,voltage fading,structural instability and adverse interface reactions in cathode materi-als of lithium-ion batteries(LIBs),numerous modification strategies have been developed,mainly including coating and doping.In particular,the important strategy of doping(surface doping and bulk doping)has been considered an effective strategy to modulate the crystal lattice structure of cathode materials.However,special insights into the mechanisms and effectiveness of the doping strategy,especially comparisons between surface doping and bulk doping in cathode materials,are still lacking.In this review,recent significant progress in surface doping and bulk doping strategies is demonstrated in detail by focusing on their inherent differences as well as effects on the structural stability,lithium-ion(Li-ion)diffusion and electrochemical properties of cathode materials from the following mechanistic insights:preventing the exposure of reactive Ni on the surface,stabilizing the Li slabs,mitigating the migration of transition metal(TM)ions,alleviating unde-sired structural transformations and adverse interface issues,enlarging the Li interslab spacing,forming three-dimensional(3D)Li-ion diffusion channels,and providing more active sites for the charge-transfer process.Moreover,insights into the correlation between the mechanisms of hybrid surface engineering strategies(doping and coating)and their influences on the electrochemical performance of cathode materials are provided by emphasizing the stabilization of the Li slabs,the enhancement of the surface chemical stability,and the alleviation of TM ion migration.Furthermore,the existing challenges and future perspectives in this promising field are indicated.

关键词： Lithium-ion batteries Cathode materials Surface doping Bulk doping Hybrid surface engineering Structural stability Lithium-ion diffusion

Iterated Unscented Kalman Filter for Spacecraft Attitude Estimation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Iterated Unscented Kalman Filter for Spacecraft Attitude Est...

Research on fiber optic gyro signal de-noising based on wavelet packet soft-threshold

第37届中国控制会议

作者： huaming qian Zhenbing Qiu College of Automation Harbin Engineering University

In this paper, an iterated unscented quaternion estimator for spacecraft attitude estimation is proposed. A step length-varying iteration technique is incorporated into the unscented quaternion estimator and the corresponding termination condition is introduced to control the number of iterations and reduce the computational burden. The reference quaternion in the measurement update is redefined by the developed iteration technique. Simulation results demonstrate the superiority of the proposed new algorithm in comparison with the multiplicative extended Kalman filter, norm constraint Kalman filter and the unscented quaternion estimator under large initialization condition errors. It also shows that the proposed algorithm exhibits a faster convergence rate.

关键词： unscented quaternion estimator attitude estimation iteration technique reference quaternion

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2009年第3期20卷 607-612页

作者： qian huaming & Ma Jichen Coll.of Automation,Harbin Engineering Univ.,Harbin 150001,P.R.China Coll. of Automation Harbin Engineering Univ. Harbin 150001 P. R. China

Gyro＇s drift is not only the main drift error which influences gyro＇s precision but also the primary factor that affects gyro＇s reliability. Reducing zero drift and random drift is a key problem to the output of a gyro signal. A three-layer de-nosing threshold algorithm is proposed based on the wavelet decomposition to dispose the signal which is collected from a running fiber optic gyro （FOG）. The coefficients are obtained from the three-layer wavelet packet decomposition. By setting the high frequency part which is greater than wavelet packet threshold as zero, then reconstructing the nodes which have been filtered out noise and interruption, the soft threshold function is constructed by the coefficients of the third nodes. Compared wavelet packet de-noise with forced de-noising method, the proposed method is more effective. Simulation results show that the random drift compensation is enhanced by 13.1%, and reduces zero drift by 0.052 6°/h.

关键词： wavelet transform drift fiber optic gyro soft-threshold signal de-noising

在线全文

学校读者我要写书评

暂无评论

一种基于多通道卫星云图的台风分割方法

北京航空航天大学学报 2011年第4期37卷 466-471页

作者：钱华明姜波哈尔滨工程大学自动化学院哈尔滨150001

有效的台风主体分割能够提高台风预报的准确性.提出一种基于矢量图像的改进水平集方法进行台风分割,将C-V模型推广到矢量空间,加入了无需重新初始化的能量项;提出了一种迭代收敛条件并设计了针对云图特点的模型参数及分割方法,该方法利... 详细信息

有效的台风主体分割能够提高台风预报的准确性.提出一种基于矢量图像的改进水平集方法进行台风分割,将C-V模型推广到矢量空间,加入了无需重新初始化的能量项;提出了一种迭代收敛条件并设计了针对云图特点的模型参数及分割方法,该方法利用了多通道的云图信息,避免了无谓的迭代计算,能够加快分割曲线的演化速度并提高分割的准确性.实验结果验证了所提出方法的有效性和可行性,其平均目标错误率与平均非目标错误率分别为1.21%与2.25%,可得到较理想的台风分割效果.

关键词：图像分割水平集 C-V模型卫星图像气象预报

联合MRGP和PSO的工业机器人驱动器可靠性分析

在线全文

学校读者我要写书评

暂无评论

系统工程与电子技术 2023年第8期45卷 2643-2650页

作者：曾颖李彦锋王弘毅钱华明黄洪钟电子科技大学机械与电气工程学院四川成都611731 电子科技大学系统可靠性与安全性研究中心四川成都611731 重庆大学机械传动国家重点实验室重庆400044

作为工业机器人的核心部件之一,驱动器失效频发,失效模式多样且具有一定相关性,给工业机器人的正常工作带来了严峻挑战。同时,工业机器人驱动器各失效模式的极限状态方程复杂,甚至一些为隐函数,这也造成了工业机器人驱动器可靠性建模的... 详细信息

作为工业机器人的核心部件之一,驱动器失效频发,失效模式多样且具有一定相关性,给工业机器人的正常工作带来了严峻挑战。同时,工业机器人驱动器各失效模式的极限状态方程复杂,甚至一些为隐函数,这也造成了工业机器人驱动器可靠性建模的困难。为此,本文引入多维响应高斯过程(multiple response Gaussian process,MRGP)模型来刻画驱动器内各失效模式间的相关性及其极限状态方程,同时引入粒子群优化(particle swarm optimization,PSO)算法优化MRGP模型中的超参数,结合主动学习策略,对MRGP模型进行更新迭代,直至其满足一定精度条件,形成基于MRGP-PSO的工业机器人驱动器可靠性分析方法。最后开展相关算例分析,验证了所提方法的有效性。

关键词：工业机器人驱动器多维响应高斯过程粒子群优化算法可靠性分析

基于广义连续时间贝叶斯网络的指挥控制网络系统可靠性分析

在线全文

学校读者我要写书评

暂无评论

系统工程与电子技术 2022年第12期44卷 3880-3886页

作者：李懿凡钱华明黄洪钟张庭瑜黄土地电子科技大学机械与电气工程学院四川成都611731 电子科技大学系统可靠性与安全性研究中心四川成都611731 重庆大学机械传动国家重点实验室重庆400044

指挥控制网络作为典型的复杂网络系统,其可靠性通常可以利用动态贝叶斯网络(dynamic Bayesian network,DBN)来分析。由于DBN并不能很好地解决包含时间和非时间事件的指挥控制网络系统可靠性问题,因此提出一种具有二态条件概率表的广义... 详细信息

指挥控制网络作为典型的复杂网络系统,其可靠性通常可以利用动态贝叶斯网络(dynamic Bayesian network,DBN)来分析。由于DBN并不能很好地解决包含时间和非时间事件的指挥控制网络系统可靠性问题,因此提出一种具有二态条件概率表的广义连续时间贝叶斯网络(generalized continuous time Bayesian network,GCTBN)的建模方法。在此模型的基础上,得到了不同逻辑门的可靠度算法求解,进而针对指挥控制网络系统提出了无线电传播、通信设备以及网络的可靠性分析方法,从而综合地考虑到指挥控制网络执行不同任务的可靠性问题。通过对指挥控制网络可靠性问题的实际案例分析,验证了所提方法的有效性。

关键词：指挥控制网络二态条件概率表贝叶斯网络可靠性分析

基于ALK-MCS算法的航空发动机轴承可靠性分析

在线全文

学校读者我要写书评

暂无评论

电子科技大学学报 2022年第3期51卷 438-443页

作者：黄洪钟童辉邓智铭钱华明李彦锋郭超电子科技大学机械与电气工程学院成都611731 电子科技大学系统可靠性与安全性研究中心成都611731 中国航空发动机研究院北京顺义区101304 重庆大学机械传动国家重点实验室重庆沙坪坝区400044

作为航空发动机的关键部件,主轴圆柱滚子轴承的可靠性水平直接影响航空发动机性能的稳定性与服役的安全性,因此准确分析主轴圆柱滚子轴承的可靠性至关重要。然而,圆柱滚子轴承的失效行为复杂,其可靠性分析中的功能函数呈现高度非线性且... 详细信息

作为航空发动机的关键部件,主轴圆柱滚子轴承的可靠性水平直接影响航空发动机性能的稳定性与服役的安全性,因此准确分析主轴圆柱滚子轴承的可靠性至关重要。然而,圆柱滚子轴承的失效行为复杂,其可靠性分析中的功能函数呈现高度非线性且无法给出显式表达,此时使用代理模型近似构建圆柱滚子轴承的功能函数是一种行之有效的方法。将蒙特卡洛模拟法(MCS)和Kriging代理模型相结合,提出了基于主动学习Kriging(ALK)的ALK-MCS算法,并将该算法应用于某型号航空发动机主轴圆柱滚子轴承的可靠性分析。首先,建立圆柱滚子轴承的三维模型,其次对圆柱滚子轴承进行有限元仿真,最后基于ALK-MCS算法对其进行可靠性分析。结果表明ALK-MCS算法计算效率高,显著减少了圆柱滚子轴承的仿真次数,所得到的可靠性分析结果可为实际工程中的决策者提供参考。

关键词：航空发动机 ALK-MCS 圆柱滚子轴承 Kriging代理模型可靠性分析

在线全文

学校读者我要写书评

暂无评论

四元数约束的容积卡尔曼滤波及其应用

哈尔滨工业大学学报 2014年第7期46卷 40-46页

作者：钱华明黄蔚孙龙哈尔滨工程大学自动化学院哈尔滨150001

针对一些非线性系统状态变量中存在四元数约束的情况,提出了一种四元数约束下的容积卡尔曼滤波(quaternion constrained cubature kalman filter,QCCKF)算法.基于最小约束代价函数,采用三阶球面-相径容积规则近似计算系统状态的后验均... 详细信息

针对一些非线性系统状态变量中存在四元数约束的情况,提出了一种四元数约束下的容积卡尔曼滤波(quaternion constrained cubature kalman filter,QCCKF)算法.基于最小约束代价函数,采用三阶球面-相径容积规则近似计算系统状态的后验均值和协方差,给出了QCCKF滤波递推公式.设计的QCCKF算法可以有效地对状态进行估计,扩展了CKF的应用范围.最后对飞行器姿态估计系统进行仿真,仿真结果表明,该算法估计精度优于常规CKF和无迹四元数估计法(unscented quaternion estimator,USQUE),并满足四元数约束条件,较好地解决了非线性系统存在四元数约束的问题,验证了算法的有效性.

关键词：容积卡尔曼滤波四元数约束最小约束代价函数三阶球面-相径容积规则