共查询到17条相似文献,搜索用时 125 毫秒
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基于ANFIS的温度传感器非线性校正方法 总被引:8,自引:3,他引:8
介绍了用神经网络进行传感器非线性误差校正的原理与方法,分析了自适应神经模糊推理系统(ANFIS)的基本原理。通过模糊聚类和混合学习算法,ANFIS可以逼近高阶输入输出非线性系统,将该算法用于两个典型非线性系统建模,均能获得满意结果。之后,将ANFIS算法用于温度传感器非线性校正中,试验结果表明该方法与基于CMAC网络和BP网络的校正方法相比,校正的精度高于以上两种校正方法。 相似文献
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针对多输出非线性系统动态模型的辨识问题,提出一种新的非线性系统动态参数化建模方法,即冗余向前延拓正交(Redundant extended forward orthogonal regression,REFOR)算法。该算法旨在消除传统向前延拓正交(Extended forward orthogonal regression,EFOR)算法因遗漏某些重要模型项而造成所建模型精度较低的问题。首先,基于系统在各工况下辨识所得非线性有源自回归(Non-linear autoregressive with exogenous inputs,NARX)模型,利用REFOR算法统一各模型结构得到模型系数与设计参数间的函数关系,进而建立多输出非线性系统的动态参数化模型。其次,以四自由度非线性系统为例,说明了REFOR算法的优势及其在系统建模中的应用。最后,利用REFOR算法建立悬臂梁的动态参数化模型,并将REFOR预测输出与试验测得输出进行对比,试验结果表明,基于REFOR算法建立的非线性系统动态参数化模型,能准确预测系统的输出响应,为非线性系统建模方法的优化设计提供了理论基础。 相似文献
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为提高硬质合金材料精密外圆磨削的表面完整性和加工质量,研究其表面质量的预测技术,建立了基于自适应模糊推理系统(ANFIS)的YG3硬质合金精密外圆磨削表面粗糙度预测模型,并引入混合田口遗传算法(HTGA)对预测模型进行了改进。采用工艺试验中所用的磨削参数及相应条件下测得的表面粗糙度数据作为训练样本和测试样本,通过对BP神经网络模型、传统ANFIS预测模型及改进ANFIS预测模型的预测结果进行对比分析,对三种模型的有效性和预测精度进行了验证。结果表明,所提出的改进ANFIS预测模型从预测值相对误差Er的分布及均方根相对误差EMSRE的大小来看,均优于其他两种预测模型,预测精度较高,是一种有效的表面质量预测方法。
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针对非线性系统模型的辨识问题,通过引入正交匹配追踪(Orthogonal matching pursuit,OMP)算法实现快速非线性系统建模。该方法旨在解决非线性有源自回归(Nonlinear autoregressive with exogenous inputs,NARX)模型针对大型数据建模时效性差的问题。首先,说明了正交最小二乘(Orthogonal least squares,OLS)算法存在正交次数多、耗时长的问题,采用OMP算法可有效解决,通过与OLS算法对比正交差异性证明了OMP算法计算效率提升的理论基础,采用模型预报方法验证OMP算法所得NARX模型的动力学特性。其次,以单自由度非线性系统为例,说明了OMP算法系统建模的有效性。最后,利用OMP算法建立悬臂梁NARX模型,并分别将NARX模型预报输出与试验实测输出,NARX模型固有频率与悬臂梁实际固有频率进行对比。结果表明,与OLS算法相比,所提方法的建模效率平均提升了10倍,且模型可有效反应系统动力学特性。 相似文献
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对于混入色噪声的混合信号,如果可以通过测量得到产生色噪声的白噪声,对白噪声进行非线性训练即可逼近色噪声,达到非线性滤波的目的.自适应模糊推理系统(adaptive neuro-fuzzy unference system,ANFIS)可以实现上述非线性逼近.文中在上述算法的基础上,提出一种EMD(empirical mode decomposition)-ANFIS的自适应色噪声消除方法,首先对混合信号进行EMD分解,得到各个内禀模态函数分量(intrinsic mode function, IMF),然后对分解得到的内禀模态分量进行ANFIS模糊消噪,最后对消噪后的各个分量信号进行叠加.由于所得内禀模态函数为近似平稳信号,且图形越来越趋于平缓,减小了ANFIS方法的逼近难度.在混合信号信噪比为2.840 7 dB时,经过EMD-ANFIS消噪后的估计误差比只经过ANFIS消噪后的估计误差减少11.74 dB,证明EMD-ANFIS方法的有效性. 相似文献
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基于Volterra级数及神经网络的非线性系统建模 总被引:1,自引:0,他引:1
在高压下,压力传感器往往会表现出非线性的特性.本文基于反向传播神经网络对Volterra级数表示的非线性系统进行了研究.在分析了神经网络分解后的结构与Volterra级数表示的非线性系统之间的类似关系后,将所使用神经网络中的激励函数在阀值处进行泰勒级数分解,解算出了Volterra级数的各阶核,从而实现了对非线性系统(传感器)的建模.实例建模结果表明,通过使用神经网络方法求解Volterra级数核来对非线性系统进行建模的方法非常有效. 相似文献
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Discharge estimation in rivers is the most important parameter in flood management. Predicting discharge in the compound open channel by analytical approach leads to solving a system of complex nonlinear equations. In many complex mathematical problems that lead to solving complex problems, an artificial intelligence model could be used. In this study, the adaptive neuro fuzzy inference system (ANFIS) is used for modeling and predicting of flow discharge in the compound open channel. Comparison of results showed that the divided channel method with horizontal division lines with the Coefficient of determination (0.76) and root mean square error (0.162) is accurate among the analytical approaches. The ANFIS model with the coefficient of determination (0.98) and root mean square error (0.029) for the testing stage has suitable performance for predicting the discharge of flow in the compound open channel. During the development of the ANFIS model, found that the relative depth, ratio of hydraulics radius and ratio of the area are the most influencing parameters in discharge prediction by the ANFIS model. 相似文献
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The Application of an ANFIS and Grey System Method in Turning Tool-Failure Detection 总被引:6,自引:0,他引:6
S.-P. Lo 《The International Journal of Advanced Manufacturing Technology》2002,19(8):564-572
The cutting process is a major material removal process; hence, it is important to search for ways of detecting tool failure.
This paper describes the results of the application of an adaptive-network-based fuzzy inference system (ANFIS) for tool-failure
detection in a single-point turning operation. In a turning operation, wear and failure of the tool are usually monitored
by measuring cutting force, load current, vibration, acoustic emission (AE) and temperature. The AE signal and cutting force
signal provide useful information concerning the tool-failure condition. Therefore, five input parameters of the combined
signals (AE signal and cutting force signal) have been used in the ANFIS model to detect the tool state. In this model, we
adopted three different types of membership function for analysis for ANFIS training and compared their differences regarding
the accuracy rate of the tool-state detection. The result obtained for the successful classification of tool state with respect
to only two classes (normal or failure) is very good. The results also indicate that a triangular MF and a generalised bell
MF have a better rate of detection. We also applied grey relational analysis to determine the order of influence of the five
cutting parameters on tool-state detection. 相似文献
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This paper presents the application of adaptive neuro-fuzzy inference system (ANFIS) for prediction of fluid density in a previously designed and constructed gamma ray densitometer for pipes of various diameters and different fluids densities. The input parameters of the proposed ANFIS model are the pipe diameter and the number of the counted photons and the output is the density of the considered material. The required data for training and testing the ANFIS model has been obtained based on simulations using MCNP4C Monte Carlo code. A hybrid learning algorithm consists of back-propagation and least-squares estimation is used for training the proposed ANFIS model. Simulations for 4-in. polyethylene pipe had been validated with the experimental data previously. The proposed ANFIS model has achieved good agreement with the experimental results and has a small error between the estimated and experimental values. The obtained results show that the mean relative error percentage (MRE%) for training and testing data are less than 2.14% and 2.64%, respectively. 相似文献