Study of a New Improved PSO-BP Neural Network Algorithm

In order to overcome shortcomings of traditional BP neural network,such as low study efficiency, slow convergence speed,easily trapped into local optimal solution,we proposed an improved BP neural network model based on adaptive particle swarm optimization( PSO) algorithm. This algorithm adjusted the inertia weight coefficients and learning factors adaptively and therefore could be used to optimize the weights in the BP network. After establishing the improved PSO-BP( IPSO-BP) model,it was applied to solve fault diagnosis of rolling bearing. Wavelet denoising was selected to reduce the noise of the original vibration signals,and based on these vibration signals a wide set of features were used as the inputs in the neural network models. We demonstrate the effectiveness of the proposed approach by comparing with the traditional BP,PSO-BP and linear PSO-BP( LPSO-BP) algorithms. The experimental results show that IPSO-BP network outperforms other algorithms with faster convergence speed,lower errors,higher diagnostic accuracy and learning ability.

Coal mine safety production forewarning based on improved BP neural network

Firstly, the early warning index system of coal mine safety production was given from four aspects as per- sonnel, environment, equipment and management. Then, improvement measures which are additional momentum method, adaptive learning rate, particle swarm optimization algorithm, variable weight method and asynchronous learning factor, are used to optimize BP neural network models. Further, the models are applied to a comparative study on coal mine safety warning instance. Results show that the identification precision of MPSO-BP network model is higher than GBP and PSO-BP model, and MPSO- BP model can not only effectively reduce the possibility of the network falling into a local minimum point, but also has fast convergence and high precision, which will provide the scientific basis for the forewarnin~ management of coal mine safetv production.

Research on BP Neural Network Algorithm Based on Quasi- Newton Method

With more and more researches about improving BP algorithm, there are more improvement methods. The paper researches two improvement algorithms based on quasi-Newton method, DFP algorithm and L-BFGS algorithm. After fully analyzing the features of quasi- Newton methods, the paper improves BP neural network algorithm. And the adjustment is made for the problems in the improvement process. The paper makes empirical analysis and proves the effectiveness of BP neural network algorithm based on quasi-Newton method. The improved algorithms are compared with the traditional BP algorithm, which indicates that the imoroved BP algorithm is better.

Prediction of the Slope Solute Loss Based on BP Neural Network

The existence of soil macropores is a common phenomenon.Due to the existence of soil macropores,the amount of solute loss carried by water is deeply modified,which affects watershed hydrologic response.In this study,a new improved BP(Back Propagation)neural network method,using Levenberg–Marquand training algorithm,was used to analyze the solute loss on slopes taking into account the soil macropores.The rainfall intensity,duration,the slope,the characteristic scale of macropores and the adsorption coefficient of ions,are used as the variables of network input layer.The network middle layer is used as hidden layer,the number of hidden nodes is five,and a tangent transfer function is used as its neurons transfer function.The cumulative solute loss on the slope is used as the variable of network output layer.A linear transfer function is used as its neurons transfer function.Artificial rainfall simulation experiments are conducted in indoor experimental tanks in order to verify this model.The error analysis and the performance comparison between the proposed method and traditional gradient descent method are done.The results show that the convergence rate and the prediction accuracy of the proposed method are obviously higher than that of traditional gradient descent method.In addition,using the experimental data,the influence of soil macropores on slope solute loss has been further confirmed before the simulation.

采用改进BP-PID控制的机器人避障仿真研究

针对移动机器人避障过程中行驶路径长、寻路速度慢等问题,提出了一种改进反向传播-比例-积分-微分(BP-PID)控制器,并对移动机器人避障效果进行仿真验证。利用移动机器人在二维坐标系的避障简图,得出了移动机器人运动方程式。引用比例-积分-微分(PID)控制器和3层BP神经网络结构,利用BP神经网络的学习能力调整PID控制器参数。引用粒子群算法进行改进,通过改进粒子群算法在线优化BP-PID控制器,确保移动机器人BP-PID控制器收敛于全局最优值,从而使移动机器人避障效果更好。在不同环境中,采用Matlab软件对移动机器人避障效果进行仿真,比较改进前和改进后的移动机器人避障效果。结果显示:在不同环境中,改进前和改进后的BP-PID控制器均能使移动机器人安全地躲避障碍物;但是采用改进的粒子群算法优化BP-PID控制器,可以使移动机器人运动路径更短,迭代次数更少,搜索时间更短。采用改进BP-PID控制器,能够提高移动机器人避障过程中寻路速度,缩短行驶路径,效果更好。

基于改进 PSO-BPNN 的拖拉机液压油品质监测

为实现对拖拉机液压油品质的有效监测,保障拖拉机液压系统的平稳运行,基于改进PSO-BPNN设计一种针对拖拉机液压油品质的监测方法。首先,为研究拖拉机液压油品质恶化情况,在液压油新油的基础上配制不同比例的液压油油样。随后,搭建拖拉机液压油品质监测试验装置,并依据试验装置采集与监测液压油粘度、介电常数和温度参数。然后,设计并搭建一种基于改进PSO-BPNN的拖拉机液压油品质监测模型,该模型利用正弦调整惯性权重的PSO算法优化BPNN的权值和阈值初始值,提高模型收敛效率。最后,为验证基于改进PSO-BPNN的液压油品质监测方法的可行性,与基于传统BPNN、标准PSO-BPNN的拖拉机液压油品质监测模型进行对比。结果表明,基于改进PSO-BPNN的拖拉机液压油品质监测方法具有较快的收敛速度,监测正确率达到97.78%,为优化拖拉机液压油品质监测方法提供参考。

基于IPSO-BP的船舶航迹预测研究

目的面对复杂的海上交通及密集的物流交通流,及时有效地对船舶航迹进行跟踪预测显得尤为重要,针对传统船舶航迹预测方法精确度低且效率低下的问题,提出一种改进方法。方法在船舶自动识别系统(Automatic Identification System,AIS)数据的基础上,建立改进粒子群算法(IPSO)与BP神经网络相结合的船舶轨迹预测模型,利用船舶历史航行轨迹数据,实现对未来船舶运动的预测。选取宁波舟山港的船舶历史轨迹数据进行实验,并将IPSO-BP模型的实验结果与其他模型进行比较。结果不同模型航迹预测对比结果表明,IPSO-BP模型的性能较好,其预测精度较高,适用于船舶轨迹预测。结论使用IPSO-BP模型能够更加精准地预测船舶航迹,在船舶危险预警、船舶异常监测等方面具有重要的指导作用。

Predicting formation lithology from log data by using a neural network

In order to increase drilling speed in deep complicated formations in Kela-2 gas field, Tarim Basin, Xinjiang, west China, it is important to predict the formation lithology for drilling bit optimization. Based on the conventional back propagation （BP） model, an improved BP model was proposed, with main modifications of back propagation of error, self-adapting algorithm, and activation function, also a prediction program was developed. The improved BP model was successfully applied to predicting the lithology of formations to be drilled in the Kela-2 gas field.

Proton exchange membrane fuel cells modeling based on artificial neural networks

To understand the complexity of the mathematical models of a proton exchange membrane fuel cell (PEMFC) and their shortage of practical PEMFC control, the PEMFC complex mechanism and the existing PEMFC models are analyzed, and artificial neural networks based PEMFC modeling is advanced. The structure, algorithm, training and simulation of PEMFC modeling based on improved BP networks are given out in detail. The computer simulation and conducted experiment verify that this model is fast and accurate, and can be used as a suitable operational model for PEMFC real-time control.

基于BP-ANN与RBF-ANN的钢筋与混凝土黏结强度预测模型研究

为研究神经网络对钢筋与混凝土黏结强度的预测能力以及神经网络的输出性能,基于大量的试验数据,提出一种基于改进神经网络的变形钢筋与混凝土黏结强度预测模型,对混凝土结构的研究与实际工程应用均有着重要的意义。收集290组黏结锚固试验数据,引入基于反向传播人工神经网络(BP-ANN)与径向基函数神经网络(RBF-ANN)算法,揭示混凝土强度、保护层厚度、钢筋直径、锚固长度及配箍率对变形钢筋与混凝土黏结性能的影响规律,建立基于改进神经网络算法的钢筋与混凝土黏结强度预测模型。对比分析不同数据预处理方法和训练神经元个数对建议模型预测结果的影响,评估各经典模型与建议模型的预测精度和离散性,提出临界锚固长度计算公式。结果表明:BP-ANN预测值与试验值比值的均值、标准差及变异系数分别为1.009、0.188、0.86,其预测精度略高于RBF-ANN;建议模型能够更准确、更稳定地预测钢筋与混凝土的黏结强度,该方法为解决钢筋与混凝土黏结问题提供了新思路。

基于IGWO-BP神经网络锂电池SOC估算

针对传统BP神经网络估算电池SOC过程中,存在初始权值和阈值对预测精度影响较大的问题,引入Tent混沌映射和自适应收敛因子对灰狼算法(GWO)进行改进,改善灰狼算法易陷入局部最优、后期迭代效率不高的缺点。将改进灰狼算法(improved grey Wolf algorithm,IGWO)与BP神经网络模型结合,得到BP神经网络最优初始权值和阈值,提高预测精度和收敛速度。对锂电池充放电实验数据预处理,得到样本数据。利用MATLAB进行仿真验证,结果表明,IGWO-BP神经网络算法的预测精度相较于传统BP神经网络算法、GWO-BP神经网络算法更优,基于改进灰狼优化BP神经网络估算电池SOC的方法的绝对误差能控制在1.53%以内,有效提高了预测精度和收敛速度。

基于BP神经网络的上海生鲜农产品物流需求预测

针对传统的生鲜农产品物流非线性需求预测模型收敛速度慢、精度低等问题,构建由改进粒子群(improved particle swarm optimization,IPSO)算法优化反向传播(back propagation,BP)神经网络的预测模型。引入对立学习机制、自适应惯性权重、非对称学习因子提升粒子群(particle swarm optimization,PSO)算法的初始解质量,平衡算法的局部开发和全局搜索能力;利用IPSO算法优化BP神经网络的权值和阈值,解决BP神经网络收敛速度慢、容易陷入局部最优等问题。通过上海生鲜农产品物流需求预测实例对模型的有效性进行验证,结果显示:IPSO-BP神经网络模型在预测精度及收敛速度上均明显优于传统PSO-BP神经网络和BP神经网络模型。

Fault Attribute Reduction of Oil Immersed Transformer Based on Improved Imperialist Competitive Algorithm

The original fault data of oil immersed transformer often contains a large number of unnecessary attributes,which greatly increases the elapsed time of the algorithm and reduces the classification accuracy,leading to the rise of the diagnosis error rate.Therefore,in order to obtain high quality oil immersed transformer fault attribute data sets,an improved imperialist competitive algorithm was proposed to optimize the rough set to discretize the original fault data set and the attribute reduction.The feasibility of the proposed algorithm was verified by experiments and compared with other intelligent algorithms.Results show that the algorithm was stable at the 27th iteration with a reduction rate of 56.25%and a reduction accuracy of 98%.By using BP neural network to classify the reduction results,the accuracy was 86.25%,and the overall effect was better than those of the original data and other algorithms.Hence,the proposed method is effective for fault attribute reduction of oil immersed transformer.

基于改进PCA-BP神经网络模型的海宁市需水预测

需水预测是地区水资源规划中的重要部分,对于实现水资源合理有序开发,保障社会经济的可持续发展有重要的指导意义。采用改进PCA-BP神经网络模型对影响需水量的9个影响因子进行降维处理,并分别以海宁市2001~2014、2015~2020年数据作为训练样本和检验样本完成模型训练,其中,综合灰色预测模型GM(1,1)对降维后的影响因子独立预测,从而预测海宁市规划年需水量,并与传统定额法的需水预测结果进行对比分析。结果表明,人口、GDP、居民生活用水量、城镇公共用水量为影响海宁市需水量的主要因子;通过构建改进PCA-BP神经网络模型得到的2025、2030、2035年需水结果,比传统定额法更为真实、合理,进一步证实了预测模型的合理性,可为海宁市未来水资源规划提供指导。

基于GRA-GA-BP神经网络的家居服面料透气性能预测

本文构建了一种改进BP神经网络模型来预测家居服面料的透气性能,能为家居服设计提供重要的参考。首先,采用灰色关联分析法(Grey Relation Analysis,GRA),选择与透气率关联度较大的因素作为研究对象。其次,采用遗传算法(GA)优化BP神经网络的结构参数,构建基于灰色关联分析的遗传算法优化BP(GRA-GA-BP)神经网络预测模型。选取58种面料成分不同、织物组织各异的家居服面料,其中42种为模型训练样本,16种为测试样本对建立的模型进行验证。实验结果表明,透气率实测值与预测值平均相对误差为8.39%;对透气率实测值与预测值进行相关性分析,拟合优度R^(2)为0.976。研究表明,该预测模型预测效果良好、预测精度高,在一定程度上可以精准预测家居服面料的透气率。

基于IWOA-BP神经网络图像复原

针对传统复原算法在退化图像复原过程中存在明显滞后的问题,建立了一种改进的鲸鱼算法(Improved Whale Optimization Algorithm,IWOA)-BP神经网络图像复原模型。首先,通过Tent混沌增强初始种群的均匀性和多样性;其次,采用非线性权重和改进的收敛因子,平衡算法的全局搜索与局部寻优能力;最后,结合Levy飞行策略更新个体位置,帮助算法跳出局部最优。随后采用经典图像数据,建立IWOA-BP模型。选取PSNR、SSIM和NMSE作为网络模型的评价指标,与BP、GWO-BP、WOA-BP进行对比。实验结果表明IWOA-BP模型图像复原视觉效果更好,提高了图像复原的质量。

基于改进SABO-BP算法的电网谐波预测

针对日趋严重的电网谐波污染亟需大量谐波数据支撑分析和治理及电网谐波监测能力不足的问题,提出一种改进减法平均优化(subtraction average based optimizer, SABO)算法优化反向传播(back-propagation, BP)神经网络实现谐波预测,以缓解当前谐波数据匮乏的问题。为了克服现有SABO算法易于陷入局部最优解,初始化时使用Logistic混沌映射替代随机数,同时迭代搜索中利用黄金正弦优化算法辅助SABO跳出局部最优,从而提高BP神经网络预测准确率。最后,以某省实际运行数据验证所提改进SABAO-BP模型在谐波电压畸变率及单次谐波电压含有率预测中均具有较高准确性。

基于IPOA-BP的输电塔复合基础极限抗拔承载力预测模型

为了实现输电塔复合基础极限抗拔承载力的准确预测,克服传统理论、经验公式误差大,计算慢的问题,提出一种改进鹈鹕智能算法(IPOA)来优化BP神经网络的承载力预测模型。首先,利用SPM混沌映射、Levy飞行以及融合非线性惯性权重因子ω的正余弦优化策略,对鹈鹕优化算法(POA)改进;然后,利用IPOA对BP神经网络的权值和阈值参数寻优,得到IPOA-BP预测模型;最后,基于验证后的数值试验构建数据集,对IPOA-BP预测模型进行训练和测试。结果表明,IPOA-BP与POA-BP预测模型相比,方根误差下降65.75%,绝对平均误差下降65.79%,平均相对误差下降65.60%,可见IPOA-BP神经网络能够实现复合基础抗拔承载力较准确的预测,为该类型基础的承载力预测提供了新方法。

小波降噪及改进遗传算法的BP神经网络在基坑变形中的组合应用

以某市人民医院基坑工程为例,针对实测数据建立实测数据结合BP神经网络预测模型,小波降噪结合BP神经网络模型和小波降噪结合改进遗传算法优化的BP神经网络模型,并利用误差分析理论对基坑变形数据预测效果评价。结果表明:对比3种模型实际处理、预测数据能力,实测数据结合BP神经网络模型预测精度在1%-4%之间,小波降噪结合BP神经网络模型预测精度1%-2%之间,小波降噪结合改进遗传算法优化的BP神经网络模型预测精度在1%以内,小波降噪结合改进遗传算法优化的BP神经网络模型的预测准确率最高。针对基坑变形监测,小波降噪结合改进遗传算法优化的BP神经网络模型具有更高预测精度,可为类似工程提供实际参考。

基于IPOA-BP算法的焊接接头抗拉强度预测模型

为了更加快捷方便的获得X80管线钢管环焊缝焊接接头抗拉强度,通过IPOA-BP算法构建了X80管线钢管环焊缝焊接接头抗拉强度预测模型,引入Logistic混沌映射、反向差分进化和萤火虫算法来提高POA算法的寻优能力。模型选择焊接电流、焊接电压、焊接热输入、保护气体流量、焊接速度、送丝速度作为焊接工艺输入参数,接头抗拉强度作为输出参数。把IPOA-BP模型和POA-BP模型以及BP神经网络模型进行对比,通过训练集对模型进行训练、测试集对模型进行验证,用均方误差、平均绝对百分比误差和R^(2)来评价模型。最终结果表明,IPOA-BP算法模型预测更加精准,拟合程度更高。