首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
基于多源信息融合的膝上假肢步态识别方法   总被引:1,自引:1,他引:0  
为了实现膝上假肢的有效控制,提出基于多源信息融合的步态识别方法。首先通过搭建人体下肢多源运动信息系统获取下肢表面肌电信号、腿部角度信号和足底压力信号。针对获取的信息,采用基于小波变换的空域相关滤波对肌电信号进行消噪并提取信号特征;选择大小腿、膝关节角度作为腿部角度信号特征;将足底压力信号通过阈值法提取有效特征。在特征提取基础上,分别利用BP神经网络和有限状态机对下肢运动信息进行步态识别,并将识别结果进行融合。实验验证了该方法在平地行走、上下楼梯模式下步态识别准确率均达到95%以上。  相似文献   

2.
针对表面肌电(SEMG)信号的非平稳特性,采用bior3.1小波对在磁场刺激下从掌长肌、肱桡肌、尺侧腕屈肌和肱二头肌四块肌肉上采集的四路表面肌电信号进行了分析,并用小波变换方法提取其肌电信号的特征,构成特征矢量,输入Elman神经网络分类器进行模式识别,经过训练能够成功地识别出握拳、展拳、腕内旋、腕外旋、屈腕、伸腕、前臂内旋、前臂外旋八种运动模式.实验表明,该方法识别率高,为肌电信号的模式识别提出了一种基于磁场刺激的新方法.  相似文献   

3.
传统特征向量提取算法得到的特征向量无法识别手指不同角度动作,将幅值立方法引入特征向量的提取算法之中,并对立方计算后信号的特征量进行降数量级处理。实验表明,提出的特征向量提取算法对表面肌电信号微小特征差异的零偏差识别率达到75%,且大偏差保持在5%以下。设计的基于BP神经网络的手指运动模式分类器,能有效地提高手指运动形式的正确识别率。  相似文献   

4.
针对下肢康复训练机器人主动训练阶段患者运动检测实时性、准确性的需求,提出一种基于动态表面肌电信号的人体步态事件快速识别方法。首先,通过表面肌电信号产生过程数学建模及步态过程中肌肉活动规律分析,给出了基于表面肌电信号强度及其变化特征的步态事件感知原理;其次,以双腿股外侧肌动态表面肌电信号强度及其变化为特征,构建了用于识别支撑和摆动两个步态事件的自适应模糊神经网络模型。实验结果表明:该方法识别结果正确率达95.3%,对足跟触地和脚尖离地事件发生时刻进行识别的平均时间误差分别为21.4ms和24.5ms,同时证明,该方法对步态之间表面肌电信号的差异具有较强的鲁棒性。  相似文献   

5.
基于Wavelet-HMM的旋转机械故障诊断方法研究   总被引:1,自引:1,他引:0  
隐Markov模型是一个双随机过程,适用于动态过程的时间序列的建模并具有强大的时序模式分类能力,特别适合非平稳、重复再现性不佳的信号分析;小波变换具有多分辨率分析的特点,在时频两域都具有表征信号局部特征的能力。文中将小波变换和隐Markov模型相结合,提出基于小波变换的HMM状态识别法,利用Daubechies小波进行8尺度的小波分解,然后从小波分解结构中提取一维信号的低频系数作为特征向量,将其输入到各个状态HMM来进行训练,其中输出概率最大的状态即是机组运行状态,从而实现状态的识别,实验结果表明该方法很有效。  相似文献   

6.
为了准确提取个体运动想象脑电信号的最优时段和频段特征以及有效提高其分类准确率,结合卷积神经网络和集成分类方法提出一种多特征卷积神经网络(MFCNN)算法,对运动想象脑电信号进行分类识别。首先对脑电信号进行预处理,然后将原始信号、能量特征、功率谱特征以及融合特征分别输入到卷积神经网络中得到其训练模型,最后通过加权投票的集成分类方法得到最终的分类结果。并利用2008年BCI竞赛Datasets 2b数据集和实测数据对所提出的方法进行实验分析。结果表明,所提的MFCNN方法可有效提高运动想象识别率,实验中所有受试者的平均分类正确率和平均Kappa值分别为78.6%和0.57,为运动想象类脑机接口的应用提供了新的思路和方法。  相似文献   

7.
针对现有癫痫脑电(EEG)识别算法分类模式单一、普适性不强的问题,提出了一种新的基于双密度离散小波变换(DDDWT)和Log-Logistic参数回归(LLPR)的脑电信号自动识别方法。不仅利用了DD-DWT算法的分解特性,还建立了脑电信号的LLPR模型,并将二者有机的结合,从而更好的发挥算法的优势。滤波后脑电信号由DD-DWT进行6层分解,提取各子频带系数的小波域能量波形,并结合LLPR模型计算尺度参数α和形状参数β以表征信号,将构成的特征向量送入遗传算法(GA)优化的支持向量机(SVM)得出识别结果,从而实现脑电信号的自动识别。所提方法在处理A\D\E与AB\CD\E两种多模式脑电分类问题时,识别率分别为98.90%和97.75%。实验结果表明,所提算法更符合实际应用需求,可以较好地解决多类脑电信号识别问题,具有良好的普适能力和分类性能。  相似文献   

8.
模糊熵算法在提取脑电信号特征时存在信号序列长度、步长等诸多参数不易调整的问题。提出一种基于局部均值分解、模糊熵以及共空间模式算法的特征提取方法:L-FECSP算法。首先,利用LMD算法将经预处理的运动想象脑电信号分解为多个PF分量,根据左右手运动想象脑电信号所处的频段选出包含α节律和β节律的PF分量。采用模糊熵算法提取已选择的PF分量的特征,使用共空间模式算法对得到的特征进行投影映射。最后,对比投影前后的特征向量,并选取其中最具区分度的特征输入到支持向量机中用于分类。采用BCI竞赛数据集进行实验,平均分类准确率达到95.30%,实验结果表明L-FECSP特征提取方法能够有效地区分左右手运动想象脑电信号。  相似文献   

9.
针对脑机接口(brain computer interface,BCI)中2类运动想象任务的特征提取问题,提出了一种小波包分解(wavelet packet decomposition,WPD)与共同空间模式(common spatial pattern,CSP)相结合的脑电信号特征提取方法.该方法首先选择7个重要导联的脑电(electroencephalograph,EEG)信号,用‘haar’小波基进行三阶WPD分解;然后对每个导联分解后的其中5个子带进行重构,获取相关频域信息;最后对重构后信号利用CSP特征提取,获得六维特征向量.CSP与WPD相结合能够充分利用WPD的时频特性,有效避免CSP要求输入导联数过多、缺乏频域信息等缺陷.对2008年国际BCI竞赛数据和本实验室实验数据,采用该方法进行特征提取,通过概率神经网络(probabilistic neural network,PNN)分类.2种数据源分类正确率分别为92%和80%,相对于单纯的CSP特征提取,正确率分别提高5%和20%.实验结果表明:WPD与CSP相结合的特征提取算法能提取明显的特征,进而提高BCI的识别正确率.  相似文献   

10.
目的针对快速ICA(独立成分分析)算法提取胎儿心电信号通道不确定的问题,提出一种新的胎儿心电提取方法。方法先用快速ICA算法提取胎儿心电信号,再用样本熵评估快速ICA算法提取的3通道心电数据,从而识别出胎儿心电信号,最后去除胎儿心电基线漂移并采用小波软阈值去噪得到纯净的胎儿心电信号。结果相比自适应滤波算法、小波阈值去燥算法、径向基神经网络算法,该算法能更好的提取高信噪比的胎儿心电信号。结论应用快速ICA和样本熵可以准确的提取胎儿心电信号。  相似文献   

11.
An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...  相似文献   

12.
The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...  相似文献   

13.
黑棣  郑美茹 《机电工程》2016,(11):1315-1321
针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。  相似文献   

14.
The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.  相似文献   

15.
The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....  相似文献   

16.
The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...  相似文献   

17.
马立新  王宏宇 《机电工程》2015,32(1):118-122
针对传统的电力系统多目标粒子群优化算法采用权重系数法将多目标转化为单目标,从而忽视了各目标函数间的竞争关系这一问题,提出将非支配解提取法运用到电力系统多目标无功优化中,并设定了一套提取规则,以电力系统中的有功网损、电压偏差和电压稳定裕度为目标,使目标在充分竞争的情况下得出Pareto最优解,利用IEEE-14节点系统对多目标非支配解提取法的电力系统无功优化进行了仿真测试。研究结果表明,该算法一次运行可以得出多组非支配解,既有偏向单个目标的解也有兼顾所有目标的解,克服了权重系数法的盲目性和单一性,可使电力决策者根据实际问题选择最优解,具有较好的灵活性与多样性。  相似文献   

18.
A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.  相似文献   

19.
This article describes designing, implementation and tuning processes of multiple-tapped-delay-line (MTDL). Obtained MTDL can be implemented in various field-programmable-logic-devices (FPGA) devices and applied for time-to-digital-converters (TDC) construction. The task of tuning process is the tapped-delay-line (TDL) linearisation, and consists of two stages. The first stage depends on selecting an appropriate configurable-logic-block (CLB) for particular delay-segment realization and selecting proper connection between these blocks. The second tuning stage, that is essential from this article viewpoint, depends on inter CLBs connecting wires delay regulation realized directly by load regulation. The Load regulation depends on connecting an appropriate number of unused three-state-buffers or CLB inputs to the wire which delay is adjusted. Depending on the number of inputs connected to the wire its capacitance changes that influences its time-constant and finally changes its time-delay.The MTDL mathematical model, obtained characteristics and results of time-interval (TI) measurements are also presented. The derived TDL model provides information about how the particular wire delay should be changed and in which order the changes should be executed. This makes the designing process predictable and easy to carry out. Presented characteristics confirm the proper operation of presented linearisation technique. The proper operation of the whole measuring module is confirmed by obtained TIs histograms presentation.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号