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基于IMU量测信息的手机运动模态判别方法
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作者 任仁凯 彭晨 +1 位作者 钱伟行 郑昊 《南京师范大学学报(工程技术版)》 CAS 2016年第3期69-75,共7页
手机导航以其便捷和廉价得到广泛应用,而其运动模态对导航精度有较大影响.基于手机内置IMU的量测信息,研究了一种运动模态判别方法 .该方法根据人体步态相位检测法和IMU中三轴加速度计和三轴陀螺仪的六维量测信息,选择合适参数,通过对... 手机导航以其便捷和廉价得到广泛应用,而其运动模态对导航精度有较大影响.基于手机内置IMU的量测信息,研究了一种运动模态判别方法 .该方法根据人体步态相位检测法和IMU中三轴加速度计和三轴陀螺仪的六维量测信息,选择合适参数,通过对试验采样数据的处理设定阈值和辨识窗口,确定实际应用算法流程.试验结果表明,该方法实时判别手机运动模态的延时小,且在相应运动模态内的判别准确率达到100%,为后续导航算法的使用时机与过程提供了有效判断依据. 展开更多
关键词 IMU 测信息 手机导航 运动模态判别
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浅海波导中低频声场干涉简正模态的判别 被引量:2
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作者 孟瑞洁 周士弘 +1 位作者 李风华 戚聿波 《物理学报》 SCIE EI CAS CSCD 北大核心 2019年第13期194-204,共11页
浅海波导中,低频宽带声场中干涉简正模特性可用于声源定位和环境参数反演,然而实际应用中由于存在声源位置不确知、某些简正模激发较弱、模型参数选取失配等因素的制约,导致干涉简正模阶数的判别存在问题.结合水平线列阵应用,根据阵列... 浅海波导中,低频宽带声场中干涉简正模特性可用于声源定位和环境参数反演,然而实际应用中由于存在声源位置不确知、某些简正模激发较弱、模型参数选取失配等因素的制约,导致干涉简正模阶数的判别存在问题.结合水平线列阵应用,根据阵列接收信号中干涉简正模成分的波束输出角度与距离无关但与干涉简正模阶数和频率相关的波导固有频散特性,提出了一种基于阵元域接收信号自相关函数WARPING变换过滤干涉简正模,进而对其波束输出角度进行模基匹配判别简正模阶数的方法.利用2011年北黄海海域声学实验中坐底布放的32元水平线列阵接收的爆炸声脉冲信号,对方法进行了验证.并由仿真数据分析了声速剖面、海底参数和水深等参数失配及信噪比对方法性能的影响.结果表明水深变化14%以上对干涉简正模波束输出角度的提取值影响最大,可引起方法失效;声速剖面和海底参数在一定失配范围内对方法性能的影响可忽略;方法要求单阵元信噪比大于2 dB. 展开更多
关键词 浅海波导 干涉简正模 WARPING变换 模态判别 水平阵
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仿生扑翼模态分析研究与优化设计 被引量:2
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作者 崔颖 贺媛媛 《噪声与振动控制》 CSCD 2018年第A02期376-382,共7页
微型扑翼飞行器是微型飞行器和扑翼飞行器的结合,是飞行器设计领域的研究热点,但在低雷诺数下存在升力不足的现象。已有研究表明,扑翼的弯扭耦合对于提高升力有效,弯扭耦合可通过共振激励放大驱动机理来实现,但该机理对扑翼的模态提出... 微型扑翼飞行器是微型飞行器和扑翼飞行器的结合,是飞行器设计领域的研究热点,但在低雷诺数下存在升力不足的现象。已有研究表明,扑翼的弯扭耦合对于提高升力有效,弯扭耦合可通过共振激励放大驱动机理来实现,但该机理对扑翼的模态提出要求。本文首先建立仿生扑翼有限元模型,对其进行模态分析,并提出1种适用于扑翼的模态种类判别方法。为满足模态要求,提出了2种改进方案,并进行了有限元仿真验证。结合两种改进方案,提出双斜梁-主梁变截面扑翼模型。基于PCL语言对该模型进行参数化建模,采用遗传算法对其进行尺寸优化,得到满足模态要求的相对理想的仿生扑翼,为仿生扑翼的设计和优化提供重要的科学依据和工程应用价值。 展开更多
关键词 振动与波 仿生扑翼 模态分析 模态种类判别 有限元仿真 尺寸优化
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基于VMD的调频连续波雷达生命信号提取 被引量:3
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作者 屈乐乐 刘淑杰 +2 位作者 杨天虹 张丽丽 孙延鹏 《电讯技术》 北大核心 2022年第5期612-618,共7页
针对生命探测雷达心跳信号能量微弱难于准确提取的问题,提出了一种基于变分模态分解(Variational Mode Decomposition,VMD)的调频连续波雷达生命信号提取算法。该算法首先利用距离维快速傅里叶变换(Fast Fourier Transform,FFT)获得距... 针对生命探测雷达心跳信号能量微弱难于准确提取的问题,提出了一种基于变分模态分解(Variational Mode Decomposition,VMD)的调频连续波雷达生命信号提取算法。该算法首先利用距离维快速傅里叶变换(Fast Fourier Transform,FFT)获得距离剖面图,然后通过最大方差法得到目标所在距离门,接着对低通滤波后的相位信号使用VMD进行分离,并采用模态判别准则对生命信号进行重构,最后对重构信号进行FFT得到呼吸和心跳频率。雷达实测结果表明,相比于应用聚类经验模态分解(Ensemble Empirical Mode Decomposition,EEMD),所提生命信号提取算法能够有效抑制雷达回波中的呼吸谐波和噪声,更加准确有效地提取生命体征信号。 展开更多
关键词 生命探测雷达 调频连续波雷达 最大方差法 变分模态分解(VMD) 模态判别准则
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A novel multimode process monitoring method integrating LCGMM with modified LFDA 被引量:4
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作者 任世锦 宋执环 +1 位作者 杨茂云 任建国 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第12期1970-1980,共11页
Complex processes often work with multiple operation regions, it is critical to develop effective monitoring approaches to ensure the safety of chemical processes. In this work, a discriminant local consistency Gaussi... Complex processes often work with multiple operation regions, it is critical to develop effective monitoring approaches to ensure the safety of chemical processes. In this work, a discriminant local consistency Gaussian mixture model(DLCGMM) for multimode process monitoring is proposed for multimode process monitoring by integrating LCGMM with modified local Fisher discriminant analysis(MLFDA). Different from Fisher discriminant analysis(FDA) that aims to discover the global optimal discriminant directions, MLFDA is capable of uncovering multimodality and local structure of the data by exploiting the posterior probabilities of observations within clusters calculated from the results of LCGMM. This may enable MLFDA to capture more meaningful discriminant information hidden in the high-dimensional multimode observations comparing to FDA. Contrary to most existing multimode process monitoring approaches, DLCGMM performs LCGMM and MFLDA iteratively, and the optimal subspaces with multi-Gaussianity and the optimal discriminant projection vectors are simultaneously achieved in the framework of supervised and unsupervised learning. Furthermore, monitoring statistics are established on each cluster that represents a specific operation condition and two global Bayesian inference-based fault monitoring indexes are established by combining with all the monitoring results of all clusters. The efficiency and effectiveness of the proposed method are evaluated through UCI datasets, a simulated multimode model and the Tennessee Eastman benchmark process. 展开更多
关键词 Multimode process monitoring Discriminant local consistency Gaussian mixture model Modified local Fisher discriminant analysis Global fault detection index Tennessee Eastman process
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Optimal programmable unambiguous discriminator between two unknown latitudinal states 被引量:1
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作者 XiaoBing Sunian YuWei Li Tao Zhou 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2016年第10期19-24,共6页
Two unknown states can be unambiguously distinguished by a universal programmable discriminator, which has been widely discussed in previous works and the optimal solution has also been obtained. In this paper, we inv... Two unknown states can be unambiguously distinguished by a universal programmable discriminator, which has been widely discussed in previous works and the optimal solution has also been obtained. In this paper, we investigate the programmable unambiguous discriminator between two unknown "latitudinal" states, which lie in a subspace of the total state space. By equivalence of unknown pure states to known average mixed states, the optimal solution for this problem is systematically derived, and the analytical success probabilities for the optimal unambiguous discrimination are obtained. It is beyond one's expectation that the optimal setting for the programmable unambiguous discrimination between two unknown "latitudinal" states is the same as that for the universal ones. The results in this work can be used for the realization of the programmable discriminator in laboratory. 展开更多
关键词 programmable state discrimination unambiguous discrimination latitudinal state
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