A methodology, termed estimation error minimization(EEM) method, was proposed to determine the optimal number and locations of sensors so as to better estimate the vibration response of the entire structure. Utilizing...A methodology, termed estimation error minimization(EEM) method, was proposed to determine the optimal number and locations of sensors so as to better estimate the vibration response of the entire structure. Utilizing the limited sensor measurements, the entire structure response can be estimated based on the system equivalent reduction-expansion process(SEREP) method. In order to compare the capability of capturing the structural vibration response with other optimal sensor placement(OSP) methods, the effective independence(EI) method, modal kinetic energy(MKE) method and modal assurance criterion(MAC) method, were also investigated. A statistical criterion, root mean square error(RMSE), was employed to assess the magnitude of the estimation error between the real response and the estimated response. For investigating the effectiveness and accuracy of the above OSP methods, a 31-bar truss structure is introduced as a simulation example. The analysis results show that both the maximum and mean of the RMSE value obtained from the EEM method are smaller than those from other OSP methods, which indicates that the optimal sensor configuration obtained from the EEM method can provide a more accurate estimation of the entire structure response compared with the EI, MKE and MAC methods.展开更多
为了高效评估弹体在运输过程中的安全性和可靠性,探讨了一种弹体运输中加速度传感器优化布置方法。采用有限元法分析弹体固有特性,通过Fisher信息矩阵2-范数变化率(rate of change,ROC)曲线确定弹体模态阶数。运用有效独立(effective in...为了高效评估弹体在运输过程中的安全性和可靠性,探讨了一种弹体运输中加速度传感器优化布置方法。采用有限元法分析弹体固有特性,通过Fisher信息矩阵2-范数变化率(rate of change,ROC)曲线确定弹体模态阶数。运用有效独立(effective independence,EI)法,计算模态置信准则(modal assurance criterion,MAC)矩阵非对角元素均值,确定传感器布置的最少必要数量;基于模态识别,以MAC矩阵非对角元素最大值为目标,确定初始测点。应用MAC法,以空间准则为约束,考虑传感器数量的影响,比较4种优化算法,优选出传感器布置方案。通过道路模拟运输试验验证了该方法在4种典型路面下的有效性。结果表明,布置结果的MAC评价指标较EI法由0.547降至0.283,且减少了信息冗余的影响,布置方法能够有效准确地布局弹体传感器,适用于弹体振动环境状态监测。展开更多
为以较小的成本获取全面的艉部振动信息,以某自航模型为研究对象,采用局部线性嵌入(Locally Linear Embedding,LLE)对其艉部振动测点进行优化设计,获取了不同工况下振动测点重要度排序,并通过与传统的频谱分析方法对比,验证了优化结果...为以较小的成本获取全面的艉部振动信息,以某自航模型为研究对象,采用局部线性嵌入(Locally Linear Embedding,LLE)对其艉部振动测点进行优化设计,获取了不同工况下振动测点重要度排序,并通过与传统的频谱分析方法对比,验证了优化结果的合理性。结果表明,轴承部位作为桨轴激励传递的主要通道,具有较高的优先级,可对船体测点按照测点重要程度排序,选取合适的测点,进而为后续试验提供基础。展开更多
基金Project(2011CB013804)supported by the National Basic Research Program of China
文摘A methodology, termed estimation error minimization(EEM) method, was proposed to determine the optimal number and locations of sensors so as to better estimate the vibration response of the entire structure. Utilizing the limited sensor measurements, the entire structure response can be estimated based on the system equivalent reduction-expansion process(SEREP) method. In order to compare the capability of capturing the structural vibration response with other optimal sensor placement(OSP) methods, the effective independence(EI) method, modal kinetic energy(MKE) method and modal assurance criterion(MAC) method, were also investigated. A statistical criterion, root mean square error(RMSE), was employed to assess the magnitude of the estimation error between the real response and the estimated response. For investigating the effectiveness and accuracy of the above OSP methods, a 31-bar truss structure is introduced as a simulation example. The analysis results show that both the maximum and mean of the RMSE value obtained from the EEM method are smaller than those from other OSP methods, which indicates that the optimal sensor configuration obtained from the EEM method can provide a more accurate estimation of the entire structure response compared with the EI, MKE and MAC methods.
文摘为以较小的成本获取全面的艉部振动信息,以某自航模型为研究对象,采用局部线性嵌入(Locally Linear Embedding,LLE)对其艉部振动测点进行优化设计,获取了不同工况下振动测点重要度排序,并通过与传统的频谱分析方法对比,验证了优化结果的合理性。结果表明,轴承部位作为桨轴激励传递的主要通道,具有较高的优先级,可对船体测点按照测点重要程度排序,选取合适的测点,进而为后续试验提供基础。
