重要期刊的摘要范例.doc

基于Gabor变换的欠定盲信号分离新方法
DOI：
中文关键词: 非平稳信号;欠定;Gabor变换;盲信号分离
英文关键词:Non-stationary signal under-determined mixtures Gabor transform blind source separation
基金项目:
作者 单位
申永军，张光明，杨绍普
摘要点击次数: 12
全文下载次数: 2
中文摘要:
结合Gabor变换和盲信号分离的各自优点,提出了一种基于Gabor变换的欠定盲信号分离新方法。首先通过混合信号的Gabor变换系数之间的相互关系,得到了源信号个数的估计;然后对Gabor变换后的信号进行阈值处理，并进行Gabor逆变换得到新的混合信号,从而实现混合信号的升维。再利用现有的盲信号分离方法进行处理，该方法不受源信号个数的限制,因此属于一种欠定盲信号分离方法；最后,通过一组仿真信号的欠定盲分离验证了该方法的有效性。
英文摘要:
A new method of blind source separation (BSS) is proposed in under-determined mixtures based on Gabor transform, and it combines the advantages of Gabor transform and BSS. Firstly, one can obtain the estimate for the number of source signals by the ratios of the coefficients of the mixed signals in Gabor transform field. Then, the appropriate threshold values are selected to process the Gabor transform coefficients, and the inverse Gabor transform is applied to the revised signals. This obtains new combinations of source signals to increase the dimensions of mixed signals. Moreover, the existing BSS methods, such as JADE, can be applied to the new mixed signals with the existing mixed ones, and one can obtain the separated source signals. The effectivity of the method is verified by some simulated signals.
混凝土结构复杂缺陷的SWRI诊断技术
DOI：
中文关键词: 混凝土; 缺陷检测; 成像技术; 反射
英文关键词:Concrete damage detection imaging techniques reflection
基金项目:
作者 单位
骆英，李忠芳
摘要点击次数: 31
全文下载次数: 11
中文摘要:
提出了混凝土结构中任意缺陷的应力波反射成像测试与诊断方法。利用特定的数据采集方法和应力波叠前偏移成像算法,测试预埋复杂形状缺陷的混凝土试件,分别采用不同数量的应力波信号获得了多张叠前偏移剖面图像。试验结果表明,随着应力波数量的增加,叠前偏移剖面能够反映的缺陷区域更广,成像更加清晰。当利用足量应力波信号进行叠前偏移成像处理时,试验结果诊断误差很小,能满足工程的精度要求。
英文摘要:
A stress wave reflection imaging(SWRI) method is presented to test and diagnose the complex defects in the concrete structure. The method for collecting stress wavedata and the SWRI algorithm are used to detect the specimen with embedded complex defects, the corresponding pre-stack migration images are obtained by usingdifferent numbers of collected data. Results show that with the increase of the number of stress wave, the clear imaging region became broader and the image of the defect became clearer. Using adequate stress wave signals in prestack migration processing, there will be little error in SWRI diagnostic results, thus meeting accuracy requirements on engineering practice.
变精度粗糙集在齿轮故障诊断中的应用
DOI：
中文关键词: 二级齿轮箱;变负载;变精度粗糙集理论;条件属性约简;噪声数据;齿轮
英文关键词:Two-level gearbox load change variable precision rough set theory condition attribute reduction noise data gear
基金项目:
作者 单位
沈仁发,郑海起,金海薇
摘要点击次数: 13
全文下载次数: 2
中文摘要:
在二级齿轮箱的变负载过程中,为了有效地处理非平稳信号,采用小波包提取特征参量(条件属性值);为了有效地处理带噪声的数据,将变精度粗糙集理论引入到齿轮的故障诊断中,提出了一种条件属性约简方法。首先对连续属性进行离散化;然后定义集合M,根据实际情况,选取不同的正确分类率β,利用变精度粗糙集的近似分类质量进行条件属性约简,并与加入噪声数据后所得的约简结果进行了对比;最后通过齿轮故障实例验证了此方法的有效性和实用性。
英文摘要:
In the load change test, the vibration signals are measured on a two-level gearbox testbed. For coping with non-stationary signals effective, wavelet packet is used for obtaining a feature vector (values of condition attribute). For coping with noise data effective, variable precision rough set (VPRS) theory is introduced in the fault diagnosis of the gear, and a kind method of condition attribute reduction is presented. Firstly, continuous attributes are discretized.Then, the set of M is defined, and varying values of β(right ratio of classification) are selected according to the reality, and the quality of approximation classification of VPRS is utilized to carry through condition attribute reduction and contrasted its result with the reduction result coming from data (including noise data). Finally, a practical example in the gear shows the validity and practicability of the algorithm
电液位置伺服系统的抖振消弱滑模控制
DOI：
中文关键词: 抖振;电液位置伺服系统;模糊;比例滑模;增益自调整
英文关键词:Buffeting electro-hydraulic position system fuzzy proportion sliding mode gain self-adjusting
基金项目:
作者 单位
靳宝全，熊诗波，程珩
摘要点击次数: 13
全文下载次数: 2
中文摘要:
比例滑模策略保留了线性控制的某些优点,但抖振的存在不仅会降低控制精度,甚至会激发系统的未建模动态或引起机械谐振,严重制约了比例滑模控制在电液位置系统中的应用。为避免抖振对系统精度与稳定性的影响,提出采用模糊模型,根据切换函数及其导数的状态自调整比例滑模切换增益,以柔化控制信号。试验结果表明,通过模糊理论实现增益自调整,能有效降低抖振,既实现了高精度控制,又保留了滑模策略抗参数摄动及抗扰动能力强的特点。
英文摘要:
The proportion sliding mode strategy retains the linear control advantages, but the presence of buffeting will reduce the control precision, even stimulate the system unmodeled dynamics or cause mechanical resonance. These deficiencies seriously restrict the application of the proportion of sliding mode control in electrohydraulic position system. In order to avoid chattering influence on the system accuracy and stability, self-tuning sliding mode switching gain is designed to soften the control signal, according to the switch function and its derivative of the fuzzy model. The results show that the system achieves the gain self-adjusting by fuzzy theory, reduces the buffeting, implements high-precision control, and retains characteristics both of the anti-parameter perturbations and anti-disturbance ability
动力吸振技术在车内轰鸣声控制中的应用
DOI：
中文关键词: 动力吸振技术;车内轰鸣声;发动机激励;传递路径
英文关键词:dynamic vibration absorber booming noise engine excitation transfer path
基金项目:
作者 单位
兰靛靛，闵福江,邵明亮
摘要点击次数: 21
全文下载次数: 3
中文摘要:
通过分析引起某车内轰鸣声的激励源和贡献量最大的传递路径，利用实验模态技术测试分析出传动轴的弯曲模态频率，判断出该车内轰鸣声产生的原因是传动轴的强迫振动；利用动力吸振技术，进行了动力吸振器力学参数的优化设计，提出了抑制传动轴弯曲共振的工程方案。通过试验验证，该方法有效地降低了车内噪声。
英文摘要:
Ｔhe order analysis method for studying the rotary machinery vibration signal and transfer path analysis(TPA) method are used to diagnose the excitation source and the greatest contribution of transfer path, it leads to the booming noise in a passenger car. The modal test is used to measure and analyｚe the first bending nature frequency. It is found that the booming noise is caused by the forced dynamic response of transmission shaft in the resonant state. Based on the dynamic vibration absorber method, the mechanical parameters of the absorber are designed. A modification of the transmission shaft is provided to reduce the interior noise of the car and control the booming noise. The road testing proves that the visibility is improved.
一种改进的ARMA模型参数估计方法
DOI：
中文关键词: 自回归滑动平均模型;参数估计;传递函数;遗传算法;约束方程;组合目标函数
英文关键词:Auto-regressive movingaverage model parameter estimation transfer function gene algorithm constraint equation combined objective function
基金项目:
作者 单位
邓卫强,王跃钢，杨颖涛
摘要点击次数: 13
全文下载次数: 3
中文摘要:
针对自回归滑动平均(autoregressive moving average,简称ARMA)模型参数谱估计容易出现谱峰漂移问题,提出一种基于组合目标函数和遗传算法的ARMA模型参数估计方法。通过最小均方误差准则获得ARMA模型参数初始估计，依据现代谱估计理论和连续函数极值存在的必要条件推导模型参数的频域约束方程，构造组合目标函数并采用遗传算法对模型参数初始估计值进行优化获得模型参数的最优解。将该方法用于车削状态下尾顶尖垂直方向振动加速度时间序列建模和谱估计,结果表明了方法的有效性。
英文摘要:
To solve the problem of spectral peak deviation for auto-regressive moving average (ARMA) model parametric spectrum estimation, an ARMA parameter estimation method combined by objective function and gene algorithm (GA) is proposed. An initial estimate of the model parameters is acquired by minimizing Least Square Error. The constraint equation is derived according to modern spectrum theory and the necessary condition for the extreme value of continuous function. The combined objective function is constructed and the GA is used to optimize the initial parameter estimation. The method is used for modeling the vertical vibration acceleration data of back centre under turning condition and its spectrum estimation. Results demonstrate its efficiency.
基于免疫算法的内燃机配气机构型线动力学优化设计
李智 孙江波
【摘要】：建立了内燃机配气凸轮机构型线的动力学数学模型,运用免疫遗传算法和Matlab语言,对该数学模型进行了仿真优化计算,与原设计相比,仿真结果表明:丰满系数提高了1.24%,动态最大正加速度在上升段下降了0.87%,在下降段上升了5.23%,动态最大负加速度下降了5.93%,使得系统动态速度和动态加速度趋于平稳,有效的减少内燃机配气机构的冲击振动,提高了内燃机的动力性能。
【作者单位】： 武汉工业学院电气信息工程系 武汉工业学院电气信息工程系
【关键词】： 冲击振动 内燃机 配气机构 免疫算法 优化仿真
【基金】：湖南省教育厅重点科研项目(编号:2004D011)
【分类号】：TK402