CN118627381A - Construction method of natural gas pipeline network energy transmission difference calculation system integrated with machine learning - Google Patents
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Abstract
本发明提出了一种融合机器学习的天然气管网能量输差计算系统的构建方法,本能量输差计算系统包括源数据库单元、预测单元和优化单元;源数据库单元包括传感器数据源模块和其他数据模块;预测单元包括充足样本预测模块和小样本预测模块;优化单元包括实测数据模块和贝叶斯参数更新模块。主要包括以下步骤:确定能量输差影响因素构建基础数据库;聚类处理建立天然气管网能量输差机器学习回归预测模型;实时输入所需预测管段的实时传感器数据进行能量输差预测;构建优化数据库并更新机器学习模型中输入参数的权重。本发明对避免了传统方法对于人工经验的严重依赖性,计算流程简单耗时短;解决了管道运输领域的小样本问题,提高了模型的泛化性能。The present invention proposes a method for constructing a natural gas pipeline network energy transmission difference calculation system that integrates machine learning. The energy transmission difference calculation system includes a source database unit, a prediction unit, and an optimization unit; the source database unit includes a sensor data source module and other data modules; the prediction unit includes a sufficient sample prediction module and a small sample prediction module; the optimization unit includes a measured data module and a Bayesian parameter update module. It mainly includes the following steps: determining the factors affecting the energy transmission difference to construct a basic database; clustering processing to establish a machine learning regression prediction model for the energy transmission difference of the natural gas pipeline network; real-time input of real-time sensor data of the required prediction section for energy transmission difference prediction; constructing an optimization database and updating the weights of the input parameters in the machine learning model. The present invention avoids the serious dependence of traditional methods on manual experience, and the calculation process is simple and time-consuming; it solves the small sample problem in the field of pipeline transportation and improves the generalization performance of the model.
Description
技术领域Technical Field
本发明涉及天然气运输领域,特别是指一种融合机器学习的天然气管网能量输差计算系统的构建方法。The present invention relates to the field of natural gas transportation, and in particular to a method for constructing a natural gas pipeline network energy transmission difference calculation system integrating machine learning.
背景技术Background Art
如何保障天然气资源在我国城镇范围的全面覆盖是制约天然气行业发展的重要因素。其中,得益于管道运输在安全、运输成本、建设周期以及运量等方面的显著优势,成为了天然气等能源的长距离主要运输方式之一。然而,受计量装置、人员测量误差、老化管道固有损失、气质、气体流动状态、温度等诸多不确定因素的影响,天然气的长距离管道运输不可避免的会出现输差问题。这对于天然气需求侧的精准计算,管网供气方案的制订以及天然气公司的经济效益都产生了重大影响。How to ensure the comprehensive coverage of natural gas resources in my country's urban areas is an important factor restricting the development of the natural gas industry. Among them, pipeline transportation has become one of the main long-distance transportation methods for natural gas and other energy sources, thanks to its significant advantages in safety, transportation costs, construction cycle and transportation volume. However, due to many uncertain factors such as metering devices, personnel measurement errors, inherent losses in aging pipelines, gas quality, gas flow status, temperature, etc., long-distance pipeline transportation of natural gas will inevitably have transmission differences. This has a significant impact on the accurate calculation of the natural gas demand side, the formulation of pipeline network gas supply plans, and the economic benefits of natural gas companies.
目前,对于天然气的计量方式国际上通用的是能量度量单位。在选定的计量周期内,天然气的能量输差E可用式(1)计算。现常用的天然气管网能量输差计算方法主要包括:传统的SCADA系统、人工计算和调度经验模式。然而,由于上述影响因素的多样性以及不确定性,上述能量输差计算方法往往存在计算效率低,性价比低等问题。At present, the internationally accepted method for measuring natural gas is energy measurement units. Within the selected measurement period, the energy transmission difference E of natural gas can be calculated using formula (1). The commonly used methods for calculating the energy transmission difference of natural gas pipeline networks mainly include: traditional SCADA system, manual calculation and scheduling experience mode. However, due to the diversity and uncertainty of the above-mentioned influencing factors, the above-mentioned energy transmission difference calculation methods often have problems such as low calculation efficiency and low cost performance.
E=(HC)G(t1)Q (1)E=(H C ) G (t 1 )Q (1)
Q=(V1+Q1)-(Q2+Q3+Q4+V2) (2)Q=(V 1 +Q 1 )-(Q 2 +Q 3 +Q 4 +V 2 ) (2)
其中:E为能量输差,(HC)G(t1)为气体燃料的实际高位摩尔发热量,kJ/kmol,Q为某一时间输气管道内平衡输气量差值,m3;Q1为同一时间内的输入气量值,m3;Q2为同一时间内的输出气量值,m3;Q3为同一时间内输气单位的生产、生活用气量,m3;Q4为同一时间内放空气量,m3;V1为计算时间开始时,管道计算段内的储气气量,m3;V2为计算时间结束时,管道计算段内的储气气量,m3。Wherein: E is the energy transmission difference, ( HC ) G ( t1 ) is the actual high molar calorific value of the gas fuel, kJ/kmol, Q is the equilibrium gas transmission volume difference in the gas pipeline at a certain time, m3 ; Q1 is the input gas volume value in the same time, m3 ; Q2 is the output gas volume value in the same time, m3 ; Q3 is the production and living gas consumption of the gas transmission unit in the same time, m3 ; Q4 is the gas discharge volume in the same time, m3 ; V1 is the gas storage volume in the pipeline calculation section at the beginning of the calculation time, m3 ; V2 is the gas storage volume in the pipeline calculation section at the end of the calculation time, m3 .
例如,申请号为CN202010958923.3的发明专利公开了一种综合考虑实际管存和输差问题的可视化天然气管网输差优化求解系统,显著减小了能量输差的计算误差。然而,由于求解多变量微分方程组,求解过程繁琐,耗时长。同时,对于不同区段或不同服役环境下能量输差的计算适用性较差。For example, the invention patent with application number CN202010958923.3 discloses a visual natural gas pipeline network transmission difference optimization solution system that comprehensively considers the actual pipeline storage and transmission difference problems, significantly reducing the calculation error of energy transmission difference. However, due to the solution of multivariable differential equations, the solution process is cumbersome and time-consuming. At the same time, the calculation applicability of energy transmission difference in different sections or different service environments is poor.
具有高维非线性建模能力和灵活数据处理能力的数据驱动模型在近年来被广泛用于各类实际工程回归预测及分类问题。在天然气运输领域,先进传感设备的快速迭代提供了海量的精准数据,超级计算机的出现解决了算力不足的问题。基于此,人工智能计算方法为天然气管网运输能量输差的快速精准预测提供了可行解决方案。Data-driven models with high-dimensional nonlinear modeling capabilities and flexible data processing capabilities have been widely used in various practical engineering regression prediction and classification problems in recent years. In the field of natural gas transportation, the rapid iteration of advanced sensor equipment provides a large amount of accurate data, and the emergence of supercomputers solves the problem of insufficient computing power. Based on this, artificial intelligence calculation methods provide a feasible solution for the rapid and accurate prediction of energy transmission differences in natural gas pipeline transportation.
因此,基于现有传感器设备的监测数据,急需开发一种适用范围广、耗时短、准确率高的天然气管网能量输差计算方法。Therefore, based on the monitoring data of existing sensor equipment, it is urgent to develop a natural gas pipeline network energy transmission difference calculation method with wide applicability, short time consumption and high accuracy.
发明内容Summary of the invention
本发明提出一种融合机器学习的天然气管网能量输差计算系统的构建方法,能够实现天然气管道运输过程中任意区段和任意工况下能量输差的智能化回归预测。The present invention proposes a method for constructing a natural gas pipeline network energy transmission difference calculation system integrating machine learning, which can realize intelligent regression prediction of energy transmission difference in any section and under any working conditions during natural gas pipeline transportation.
本发明的技术方案是这样实现的:一种融合机器学习的天然气管网能量输差计算系统的构建方法,本能量输差计算系统包括三个单元:源数据库单元、预测单元和优化单元;The technical solution of the present invention is implemented as follows: a method for constructing a natural gas pipeline network energy transmission difference calculation system integrating machine learning, wherein the energy transmission difference calculation system includes three units: a source database unit, a prediction unit, and an optimization unit;
所述源数据库单元包括传感器数据源模块和其他数据模块;The source database unit includes a sensor data source module and other data modules;
所述预测单元包括充足样本预测模块和小样本预测模块;The prediction unit includes a sufficient sample prediction module and a small sample prediction module;
所述优化单元包括实测数据模块和贝叶斯参数更新模块;The optimization unit includes a measured data module and a Bayesian parameter updating module;
融合机器学习的天然气管网能量输差计算系统的构建流程,主要包括以下步骤:The construction process of the natural gas pipeline network energy transmission difference calculation system integrating machine learning mainly includes the following steps:
步骤一:确定能量输差影响因素,源数据库单元收集各类工程案例中天然气管网的能量输差历史数据,构建基础数据库;Step 1: Determine the factors affecting energy transmission difference. The source database unit collects the historical data of energy transmission difference of natural gas pipeline networks in various engineering cases and builds a basic database.
步骤二:预测单元对基础数据划分先进行聚类处理,分为小样本和充足样本子数据集,然后对两个子集分别划分训练集和测试集,利用训练集建立天然气管网能量输差机器学习回归预测模型;Step 2: The prediction unit first performs clustering processing on the basic data, dividing it into small sample and sufficient sample sub-datasets, and then divides the two subsets into training sets and test sets respectively, and uses the training set to establish a machine learning regression prediction model for energy transmission difference of the natural gas pipeline network;
步骤三:实时输入所需预测管段的实时传感器数据和其他工作数据,利用步骤二中训练好的模型进行能量输差预测;Step 3: Input the real-time sensor data and other working data of the pipeline section to be predicted, and use the model trained in step 2 to predict the energy transmission difference;
步骤四:优化单元中的实测数据模块收集每次能量输差检测时的实际数据,以与预测结果的误差为判断依据,保留误差在10%以下的真实样本数据并构建优化数据库;基于优化数据库中的样本与预测结果的对比定义粒子滤波中各粒子权重,并更新机器学习模型中输入参数的权重,使得误差率进一步降低。Step 4: The measured data module in the optimization unit collects the actual data during each energy transmission difference detection, and uses the error with the predicted result as the judgment basis, retains the real sample data with an error below 10% and builds an optimization database; based on the comparison between the samples in the optimization database and the predicted results, the weights of each particle in the particle filter are defined, and the weights of the input parameters in the machine learning model are updated to further reduce the error rate.
作为优选,所述步骤一中影响因素包括天然气管网管段内部气压、压降、气体流量、气体温度、实际高位摩尔发热量、初始流量、终端流量、管段长度、以及外部气压和温度,将历史案例中的上述变量构造为特征集X={x11,x12,x13,…,xij},xij表示第i个样本数的第j个特征;Preferably, the influencing factors in step 1 include internal gas pressure, pressure drop, gas flow, gas temperature, actual high molar calorific value, initial flow, terminal flow, pipe section length, and external gas pressure and temperature of the natural gas pipeline network section, and the above variables in the historical case are constructed as a feature set X={x11,x12,x13,…,xij}, where xij represents the jth feature of the i-th sample number;
所述步骤一中所收集的历史数据中的能量输差作为基本数据集的标签集Y={Y1,Y2,Y3,…,Yi}。The energy input difference in the historical data collected in the step 1 is used as the label set Y={Y1, Y2, Y3, ..., Yi} of the basic data set.
作为优选,所述步骤二中对基本数据采用K均值聚类法划分为小样本和充足样本数据子集;Preferably, in step 2, the basic data is divided into small sample data subsets and sufficient sample data subsets using K-means clustering method;
步骤二中的机器学习模型包括充足样本机器学习预测模型和小样本机器学习预测模型,其中,充足样本机器学习模型采用神经网络方法,小样本机器学习模型采用迁移学习方法。The machine learning model in step two includes a sufficient sample machine learning prediction model and a small sample machine learning prediction model, wherein the sufficient sample machine learning model adopts a neural network method, and the small sample machine learning model adopts a transfer learning method.
作为优选,所述充足样本以步骤一中所述特征集作为输入,并赋予初始化权重因子,利用训练集建立对应的神经网络模型;Preferably, the sufficient samples take the feature set in step 1 as input, and are assigned initial weight factors, and a corresponding neural network model is established using the training set;
选用迁移学习方法对小样本训练集进行训练,上述迁移学习选用特征迁移方法,该方法基于特征映射,对齐不同域内的数据分布。A transfer learning method is used to train the small sample training set. The above transfer learning uses a feature transfer method, which is based on feature mapping and aligns data distribution in different domains.
作为优选,所述迁移学习中以迁出数据的物理场为源域M,迁入数据的物理场为目标域N,源域和目标域中的特征集和标签集分别定义为Xm、Ym、Xn、Yn;所述迁移学习模型在经典特征迁移的基础上,对源于数据融合并进一步组合聚类超参数优化。Preferably, in the transfer learning, the physical field of the outgoing data is the source domain M, the physical field of the incoming data is the target domain N, and the feature set and label set in the source domain and the target domain are defined as Xm, Ym, Xn, and Yn, respectively; the transfer learning model optimizes the hyperparameters derived from data fusion and further combines clustering on the basis of classical feature migration.
作为优选,所述特征迁移的关键点在于构造映射φ,从而使得源域和目标域接近于同条件分布,本发明中选用最大均值差异,即Maximum Mean Discrepancy,缩写为MMD,评估源域和目标域的分布距离,其计算表达式为:Preferably, the key point of the feature migration is to construct a mapping φ so that the source domain and the target domain are close to the same conditional distribution. In the present invention, the maximum mean difference, i.e., Maximum Mean Discrepancy, abbreviated as MMD, is selected to evaluate the distribution distance between the source domain and the target domain, and its calculation expression is:
其中:n1、n2分别为源域和目标域数据数量,xmi∈Xm,xnj∈Xn;Where: n 1 and n 2 are the number of source domain and target domain data respectively, x mi ∈X m , x nj ∈X n ;
征映射后引入聚类方法用于构造优化指标,进一步结合随机搜索法对正则化参数寻优。After feature mapping, the clustering method is introduced to construct the optimization index, and the random search method is further combined to optimize the regularization parameter.
作为优选,优化特征映射超参数时选用K均值聚类法,具体用于特征迁移映射后的特征矩阵;此时,源域和目标域将分别生成一个聚类中心,这两个聚类中心的距离将代表源于特征与目标域特征的分布差异性;As a preferred method, K-means clustering method is used when optimizing feature mapping hyperparameters, which is specifically used for the feature matrix after feature migration mapping; at this time, a cluster center will be generated for the source domain and the target domain respectively, and the distance between the two cluster centers will represent the distribution difference between the source feature and the target domain feature;
所述两个聚类中心的距离可以以下公式定义:The distance between the two cluster centers can be defined by the following formula:
Distance(K)=||cm-cn||2 (4)Distance(K)=||c m -c n || 2 (4)
其中,cm和cn分别是特征映射后源域目标域特征的唯一聚类中心。Among them, cm and cn are the unique clustering centers of the source domain and target domain features after feature mapping.
作为优选,所述基于上述K聚类的引入,超参数的优化问题转化为Distance(K)的最小化问题,利用随机搜索法,在给定范围内正则化参数寻优。Preferably, based on the introduction of the above-mentioned K clustering, the optimization problem of the hyperparameters is transformed into a problem of minimizing Distance(K), and a random search method is used to optimize the regularization parameters within a given range.
作为优选,所述步骤三中预测未知管段的能量输差时,需要先根据待预测输入特征与基础数据集中特征的相似性分析,判断待预测问题属于小样本还是充足样本问题;确定分类后,输入待预测样本的特征集,利用对应的机器学习模型即可得到当前的能量输差预测值。Preferably, when predicting the energy transmission difference of the unknown pipe section in step three, it is necessary to first determine whether the problem to be predicted belongs to a small sample problem or a sufficient sample problem based on the similarity analysis between the input features to be predicted and the features in the basic data set; after determining the classification, the feature set of the sample to be predicted is input, and the current energy transmission difference prediction value can be obtained using the corresponding machine learning model.
作为优选,定期抽检部分管段,并基于实测信号和其他数据计算实际能量输差;即得到新增样本;同时抽检管段内,对于相对误差小于10%的样本保留,误差大于10%的样本剔除;As a preferred method, some pipe sections are randomly inspected regularly, and the actual energy transmission difference is calculated based on the measured signal and other data; that is, new samples are obtained; at the same time, within the randomly inspected pipe section, samples with a relative error of less than 10% are retained, and samples with an error of more than 10% are eliminated;
利用抽检新样本可以定义粒子滤波参数,从而进一步方向优化机器学习模型中特征工程的权重因子。By sampling new samples, particle filter parameters can be defined to further optimize the weight factors of feature engineering in machine learning models.
与现有技术相比,本发明的优点在于:Compared with the prior art, the advantages of the present invention are:
(1)本发明对避免了传统方法对于人工经验的严重依赖性;同时,相比于各类解析计算,本发明计算流程简单,耗时短。(1) The present invention avoids the heavy reliance of traditional methods on manual experience; at the same time, compared with various analytical calculations, the calculation process of the present invention is simple and time-saving.
(2)迁移学习的引入,使得本发明很好的解决了管道运输领域的小样本问题,并提高了模型的泛化性能,使得该方法适用范围更广。(2) The introduction of transfer learning enables the present invention to effectively solve the small sample problem in the field of pipeline transportation and improve the generalization performance of the model, making the method more widely applicable.
(3)优化系统的建立,可以进一度反向优化基于已有数据建立的机器学习回归预测模型,能够实时更新模型参数,克服了复杂工况下机器学习模型的预测精度低的问题。(3) The establishment of an optimization system can further reversely optimize the machine learning regression prediction model established based on existing data, and can update the model parameters in real time, thus overcoming the problem of low prediction accuracy of the machine learning model under complex working conditions.
附图说明BRIEF DESCRIPTION OF THE DRAWINGS
图1为融合机器学习的天然气管道能量输差计算系统结构示意图;FIG1 is a schematic diagram of the structure of a natural gas pipeline energy transmission difference calculation system integrating machine learning;
图2为融合机器学习的天然气管道能量输差计算系统应用流程图。Figure 2 is an application flow chart of the natural gas pipeline energy transmission difference calculation system integrating machine learning.
具体实施方式DETAILED DESCRIPTION
下面将结合本发明实施例中的附图,对本发明实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例仅是本发明一部分实施例,而不是全部的实施例。基于本发明中的实施例,本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例,都属于本发明保护的范围。The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
本发明提供了一种融合机器学习的天然气管网能量输差计算系统。The present invention provides a natural gas pipeline network energy transmission difference calculation system integrating machine learning.
该能量输差计算包括三个单元:源数据库单元、预测单元和优化单元。其中,数据库单元包括传感器数据源模块和其他数据模块;预测单元包括充足样本预测模块和小样本预测模块;优化单元包括实测数据模块和贝叶斯参数更新模块。The energy transfer difference calculation includes three units: source database unit, prediction unit and optimization unit. The database unit includes sensor data source module and other data modules; the prediction unit includes sufficient sample prediction module and small sample prediction module; the optimization unit includes measured data module and Bayesian parameter update module.
进一步的,本发明给出了融合机器学习的天然气管网能量输差计算系统的构建流程,主要包括以下步骤:Furthermore, the present invention provides a construction process of a natural gas pipeline network energy transmission difference calculation system integrating machine learning, which mainly includes the following steps:
步骤一:确定能量输差影响因素,源数据库单元的传感器数据源模块和其他数据模块收集各类工程案例中天然气管网的能量输差历史数据,构建基础数据库。Step 1: Determine the factors affecting energy transmission difference. The sensor data source module and other data modules of the source database unit collect the historical data of energy transmission difference of the natural gas pipeline network in various engineering cases to build a basic database.
步骤二:对基础数据划分先进行聚类处理,分为小样本和充足样本子数据集。然后对两个子集分别划分训练集和测试集,利用训练集建立天然气管网能量输差机器学习回归预测模型。Step 2: Cluster the basic data into small sample and sufficient sample sub-datasets. Then divide the two subsets into training sets and test sets, and use the training set to establish a machine learning regression prediction model for energy transmission difference in natural gas pipeline networks.
步骤三:实时输入所需预测管段的实时传感器数据和其他工作数据,利用步骤二中训练好的模型进行能量输差预测。Step 3: Input the real-time sensor data and other working data of the pipeline section to be predicted, and use the model trained in step 2 to predict the energy transmission difference.
步骤四:收集每次能量输差检测时的实际数据,以与预测结果的误差为判断依据,保留误差在10%以下的真实样本数据并构建优化数据库。基于优化数据库中的样本与预测结果的对比定义粒子滤波中各粒子权重,并更新机器学习模型中输入参数的权重,使得误差率进一步降低。Step 4: Collect the actual data of each energy transmission difference detection, use the error with the predicted result as the basis for judgment, retain the real sample data with an error below 10% and build an optimized database. Based on the comparison between the samples in the optimized database and the predicted results, define the weight of each particle in the particle filter, and update the weight of the input parameters in the machine learning model to further reduce the error rate.
优选的是,步骤一中影响因素包括天然气管网管段内部气压、压降、气体流量、气体温度、实际高位摩尔发热量、初始流量、终端流量、管段长度、以及外部气压,温度等,将历史案例中上述变量构造为特征集X={x11,x12,x13,…,xij},xij表示第i个样本数的第j个特征。Preferably, the influencing factors in step one include internal gas pressure, pressure drop, gas flow, gas temperature, actual high molar calorific value, initial flow, terminal flow, pipe section length, and external gas pressure, temperature, etc. of the natural gas pipeline network section, and the above variables in the historical cases are constructed as a feature set X = {x11, x12, x13, ..., xij}, where xij represents the jth feature of the i-th sample number.
步骤一中所收集的历史数据中的能量输差作为基本数据集的标签集Y={Y1,Y2,Y3,…,Yi}。The energy input difference in the historical data collected in step 1 is used as the label set Y = {Y1, Y2, Y3, ..., Yi} of the basic data set.
优选的是,步骤二中对基本数据采用K均值聚类法划分为小样本和充足样本数据子集。Preferably, in step 2, the basic data is divided into small sample data and sufficient sample data subsets using K-means clustering method.
步骤二中的机器学习模型包括充足样本机器学习预测模型(对应充足样本预测模块)和小样本机器学习预测模型(对应小样本预测模块)。其中,充足样本机器学习模型采用神经网络方法,小样本机器学习模型采用迁移学习方法。The machine learning model in step 2 includes a sufficient sample machine learning prediction model (corresponding to a sufficient sample prediction module) and a small sample machine learning prediction model (corresponding to a small sample prediction module). The sufficient sample machine learning model adopts a neural network method, and the small sample machine learning model adopts a transfer learning method.
对于充足样本问题,以步骤一中所述特征集作为输入,并赋予初始化权重因子,利用训练集建立对应的神经网络模型。For the sufficient sample problem, the feature set described in step 1 is used as input, and the initial weight factor is assigned, and the corresponding neural network model is established using the training set.
对于小样本数据问题,传统的机器学习方法预测精度往往较低。然而,迁移学习可以实现不同域内的数据相互迁移并加以利用,能有效解决小样本问题。此外,恰当的迁移准则使得迁移学习可以降低不同域内数据分布的差异性,可以解决数据多分布问题。因此,本发明选用迁移学习方法对小样本训练集进行训练。For small sample data problems, the prediction accuracy of traditional machine learning methods is often low. However, transfer learning can achieve mutual migration and utilization of data in different domains, which can effectively solve the small sample problem. In addition, appropriate migration criteria enable transfer learning to reduce the differences in data distribution in different domains, which can solve the problem of multi-distribution of data. Therefore, the present invention uses transfer learning methods to train small sample training sets.
上述迁移学习选用特征迁移方法,该方法基于特征映射,可以对齐不同域内的数据分布,对小样本问题具有较好的适用性。The above transfer learning uses the feature transfer method, which is based on feature mapping and can align data distribution in different domains. It has good applicability to small sample problems.
所述迁移学习中以迁出数据的物理场为源域M,迁入数据的物理场为目标域N。源域和目标域中的特征集和标签集分别定义为Xm、Ym、Xn、Yn。In the transfer learning, the physical field of the outgoing data is the source domain M, and the physical field of the incoming data is the target domain N. The feature set and label set in the source domain and the target domain are defined as Xm, Ym, Xn, and Yn, respectively.
优选的,上述迁移学习模型在经典特征迁移的基础上,对源于数据融合并进一步组合聚类超参数优化。Preferably, the above transfer learning model optimizes the hyperparameters derived from data fusion and further combines clustering based on the classic feature migration.
特征迁移的关键点在于构造映射φ,从而使得源域和目标域接近于同条件分布。本发明中选用最大均值差异(Maximum Mean Discrepancy,MMD)评估源域和目标域的分布距离,其计算表达式为:The key point of feature migration is to construct a mapping φ so that the source domain and the target domain are close to the same conditional distribution. In this invention, the maximum mean discrepancy (MMD) is used to evaluate the distribution distance between the source domain and the target domain, and its calculation expression is:
其中:n1、n2分别为源域和目标域数据数量, Where: n 1 and n 2 are the number of source domain and target domain data respectively,
基于上述公式,特征迁移映射的构造可由最小化最大均值差异决定。类似于其他机器学习方法,通过引入核函数和正则化项,可以将最大均值差异的最小化问题转化为优化问题。Based on the above formula, the construction of the feature transfer map can be determined by minimizing the maximum mean difference. Similar to other machine learning methods, by introducing kernel functions and regularization terms, the problem of minimizing the maximum mean difference can be transformed into an optimization problem.
优选的是,要想达到较好的特征迁移效果,必须对正则项进行参数寻优。考虑到数据分布的差异性,本发明在特征映射后同样引入了聚类方法用于构造优化指标,进一步结合随机搜索法对正则化参数寻优。Preferably, in order to achieve a better feature migration effect, the regularization term must be optimized. Considering the differences in data distribution, the present invention also introduces a clustering method after feature mapping to construct an optimization index, and further combines the random search method to optimize the regularization parameter.
优化特征映射超参数时选用K均值聚类法,具体用于特征迁移映射后的特征矩阵。此时,源域和目标域将分别生成一个聚类中心,这两个聚类中心的距离将代表源于特征与目标域特征的分布差异性。When optimizing feature mapping hyperparameters, K-means clustering is used, which is specifically used for the feature matrix after feature migration mapping. At this time, a cluster center will be generated for the source domain and the target domain respectively, and the distance between the two cluster centers will represent the distribution difference between the source and target domain features.
上一步中的两个聚类中心的距离可以以下公式定义:The distance between the two cluster centers in the previous step can be defined by the following formula:
Distance(K)=||cm-cn||2 (4)Distance(K)=||c m -c n || 2 (4)
其中,cm和cn分别是特征映射后源域目标域特征的唯一聚类中心。Among them, cm and cn are the unique clustering centers of the source domain and target domain features after feature mapping.
基于上述K聚类的引入,超参数的优化问题转化为Distance(K)的最小化问题。可以利用随机搜索法,在给定范围内正则化参数寻优。Based on the introduction of K clustering, the optimization problem of hyperparameters is transformed into the problem of minimizing Distance(K). The random search method can be used to optimize the regularization parameters within a given range.
优选的是,步骤三中预测未知管段的能量输差时,需要先根据待预测输入特征与基础数据集中特征的相似性分析,判断待预测问题属于小样本还是充足样本问题。Preferably, when predicting the energy transmission difference of the unknown pipe section in step three, it is necessary to first determine whether the problem to be predicted is a small sample problem or a sufficient sample problem based on the similarity analysis between the input features to be predicted and the features in the basic data set.
确定分类后,输入待预测样本的特征集,利用对应的机器学习模型即可得到当前的能量输差预测值。After determining the classification, input the feature set of the sample to be predicted, and use the corresponding machine learning model to obtain the current energy output difference prediction value.
优选的是,由于能量输差在天然气管道中的重要性,不可避免的会定期抽检部分管段,并基于实测信号和其他数据计算实际能量输差。即,得到新增样本。同时,对于抽检管段内,预测值与真实值之间不可避免会存在一定的误差。对于相对误差小于10%的样本保留,误差大于10%的样本剔除。Preferably, due to the importance of energy transmission difference in natural gas pipelines, it is inevitable to periodically sample some pipe sections and calculate the actual energy transmission difference based on the measured signal and other data. That is, to obtain new samples. At the same time, for the sampled pipe section, there will inevitably be a certain error between the predicted value and the true value. Samples with a relative error of less than 10% are retained, and samples with an error of more than 10% are eliminated.
进一步的,利用抽检新样本可以定义粒子滤波参数,从而进一步方向优化机器学习模型中特征工程的权重因子。Furthermore, the particle filter parameters can be defined by sampling new samples, thereby further optimizing the weight factors of feature engineering in the machine learning model.
优选的是,重复上述步骤一到四,即可得到任意区段天然气管道的能量输差。Preferably, by repeating the above steps 1 to 4, the energy transmission difference of any section of the natural gas pipeline can be obtained.
相比于现有能量输差计算方法,本发明的有益效果是:Compared with the existing energy transfer difference calculation method, the beneficial effects of the present invention are:
(1)本发明对避免了传统方法对于人工经验的严重依赖性。同时,相比于各类解析计算,本发明计算流程简单,耗时短。(1) The present invention avoids the heavy reliance of traditional methods on manual experience. At the same time, compared with various analytical calculations, the present invention has a simple calculation process and takes less time.
(2)迁移学习的引入,使得本发明很好的解决了管道运输领域的小样本问题,并提高了模型的泛化性能,使得该方法适用范围更广。(2) The introduction of transfer learning enables the present invention to effectively solve the small sample problem in the field of pipeline transportation and improve the generalization performance of the model, making the method more widely applicable.
(3)优化系统的建立,可以进一度反向优化基于已有数据建立的机器学习回归预测模型,能够实时更新模型参数,克服了复杂工况下机器学习模型的预测精度低的问题。(3) The establishment of an optimization system can further reversely optimize the machine learning regression prediction model established based on existing data, and can update the model parameters in real time, thus overcoming the problem of low prediction accuracy of the machine learning model under complex working conditions.
下面结合附图实施例对本发明构思和应用流程做进一步的详细说明,以令本领域技术人员参照说明书文字能够据以实施。The concept and application process of the present invention are further described in detail below in conjunction with the embodiments of the drawings, so that those skilled in the art can implement them according to the description.
如图1所示,融合机器学习的天然气管道能量输差计算系统包括源数据库单元、预测单元和优化单元。As shown in Figure 1, the natural gas pipeline energy transmission difference calculation system integrating machine learning includes a source database unit, a prediction unit, and an optimization unit.
如图2所示一种融合机器学习的天然气管道能量输差计算系统的实施流程。结合图1、图2,该系统的具体实施流程包含以下步骤:FIG2 shows an implementation process of a natural gas pipeline energy transmission difference calculation system integrating machine learning. Combined with FIG1 and FIG2, the specific implementation process of the system includes the following steps:
S1:基于人工经验和已有研究确定影响能量输差的因素。源数据库单元的其他数据模块从各类公开工程案例、已发表文献、天然气公司数据库等收集包含能量输差的历史结构化和非结构化数据集。将各影响因素作为特征集,能量输差结果作为标签值,构建天然气管网能量输差源数据库。S1: Determine the factors that affect the energy transmission difference based on manual experience and existing research. Other data modules of the source database unit collect historical structured and unstructured data sets containing energy transmission difference from various public engineering cases, published literature, natural gas company databases, etc. Take each influencing factor as a feature set and the energy transmission difference result as a label value to construct a natural gas pipeline network energy transmission difference source database.
对源数据库数据进行预处理,剔除缺失数据和异常数据。同时,由于涉及的影响因素较多,不同类型数据的分布范围存在较大差异,甚至存在量级差距。因此,对筛选后源数据集标准归一化处理。The source database data is preprocessed to remove missing data and abnormal data. At the same time, due to the large number of influencing factors involved, the distribution ranges of different types of data vary greatly, and even have magnitude differences. Therefore, the source data set after screening is standardized and normalized.
利用K均值聚类法,将源数据集划分为小样本和充足样本数据集。Using K-means clustering method, the source data set is divided into small sample data set and sufficient sample data set.
对于充足样本数据集和小样本数据集,分别将归一化处理后的特征构造成特征矩阵,以便于后续机器学习模型的训练。For sufficient sample data sets and small sample data sets, the normalized features are constructed into feature matrices to facilitate the subsequent training of machine learning models.
S2:基于S1中数据集的聚类划分,分别就两类数据进行机器学习模型训练。S2: Based on the clustering division of the data set in S1, machine learning model training is performed on two types of data respectively.
其中,对于充足样本数据集,按照3:7的比例划分训练集和测试集。以各影响因素为输入,能量输差为输出,均方根误差为损失函数。初始化神经网络权重和偏置项。在一定范围内利用随机搜索法对超参数寻优。For sufficient sample data sets, the training set and test set are divided into 3:7 ratios. Each influencing factor is used as input, the energy input difference is used as output, and the root mean square error is used as the loss function. The neural network weights and bias terms are initialized. The random search method is used to optimize the hyperparameters within a certain range.
上述神经网络超参数包括激活函数、正则化系数、学习率、最大迭代次数等。根据样本数据量、输入量等给定超参数寻优区间,综合考虑准确率、稳定性能选择最优超参数。The above-mentioned neural network hyperparameters include activation function, regularization coefficient, learning rate, maximum number of iterations, etc. The optimal hyperparameters are selected by giving the hyperparameter optimization interval according to the sample data volume, input volume, etc., and comprehensively considering the accuracy and stability.
对于小样本问题,适用迁移学习构造回归预测模型。将小样本源数据集划分为源域和目标域,并利用特征映射将源域数据和目标域数据映射为两个更加接近的特征矩阵。For small sample problems, transfer learning is used to construct a regression prediction model. The small sample source data set is divided into the source domain and the target domain, and feature mapping is used to map the source domain data and the target domain data into two closer feature matrices.
在上述映射过程中,同时引入K均值聚类实现问题转化,并以最小化聚类中心距离为目标,结合随机搜索法自动寻优特征映射的正则化超参数。In the above mapping process, K-means clustering is introduced to realize problem transformation, and the regularization hyperparameters of feature mapping are automatically optimized by combining the random search method with the goal of minimizing the cluster center distance.
对于映射后的新源域和目标域数据集,同样采用神经网络作为预测器,并定义粒子滤波中各粒子权重寻优。并以均方根误差、决定系数为评价指标,得到最优的迁移学习模型。以管段的实测传感器数据和其他非传感器数据作为输入,预测当前管段的能量输差。For the mapped new source and target domain data sets, neural networks are also used as predictors, and the weights of each particle in the particle filter are defined to find the best. The root mean square error and determination coefficient are used as evaluation indicators to obtain the optimal transfer learning model. The measured sensor data and other non-sensor data of the pipe section are used as input to predict the energy output difference of the current pipe section.
值得注意的是,采用迁移学习可以提高小样本工况的预测准确率。同时,迁移学习的使用使得不同管段、不同服役环境下天然气管段的能量输差准确预测成为可能。It is worth noting that the use of transfer learning can improve the prediction accuracy of small sample conditions. At the same time, the use of transfer learning makes it possible to accurately predict the energy transmission difference of natural gas pipeline sections in different pipeline sections and different service environments.
S3:传感器数据源模块收集各管道定期抽检数据集,并以与预测结果的相对误差作为评价职表,保留相对误差小于10%的抽检样本。结合贝叶斯参数更新模块进行优化,定义粒子滤波中各粒子权重,以最小化相对误差为目标,反向传递改变网络节点权重,更新机器学习模型,以其实现回归模型的自动更新。S3: The sensor data source module collects regular sampling data sets from each pipeline, and uses the relative error with the predicted result as an evaluation table, retaining sampling samples with a relative error of less than 10%. Combined with the Bayesian parameter update module for optimization, the weights of each particle in the particle filter are defined, with the goal of minimizing the relative error, and the network node weights are changed in reverse transmission to update the machine learning model to achieve automatic update of the regression model.
重复以上步骤,即可实现任意管段的能量输差回归预测。By repeating the above steps, the energy transmission difference regression prediction of any pipe section can be realized.
以上所述仅为本发明的较佳实施例而已,并不用以限制本发明,凡在本发明的精神和原则之内,所做的任何修改、等同替换、改进等,均应包含在本发明的保护范围之内。The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
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Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112085086A (en) * | 2020-09-03 | 2020-12-15 | 哈尔滨工业大学 | Multi-source transfer learning method based on graph convolution neural network |
US20210287122A1 (en) * | 2018-08-23 | 2021-09-16 | Mitsubishi Power, Ltd. | Prediction device, prediction method, and program |
CN117113034A (en) * | 2023-09-19 | 2023-11-24 | 中国建筑第四工程局有限公司 | Tunnel excavation earth surface subsidence prediction method based on deep learning and feature transfer learning |
-
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- 2024-06-12 CN CN202410752266.5A patent/CN118627381A/en active Pending
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20210287122A1 (en) * | 2018-08-23 | 2021-09-16 | Mitsubishi Power, Ltd. | Prediction device, prediction method, and program |
CN112085086A (en) * | 2020-09-03 | 2020-12-15 | 哈尔滨工业大学 | Multi-source transfer learning method based on graph convolution neural network |
CN117113034A (en) * | 2023-09-19 | 2023-11-24 | 中国建筑第四工程局有限公司 | Tunnel excavation earth surface subsidence prediction method based on deep learning and feature transfer learning |
Non-Patent Citations (3)
Title |
---|
HU, DL 等: "Flow Adversarial Networks: Flowrate Prediction for Gas-Liquid Multiphase Flows Across Different Domains", IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS, 28 April 2020 (2020-04-28) * |
廖绮 等: "人工智能赋能油气管道智慧运行的应用及展望", 油气储运, 13 March 2024 (2024-03-13) * |
郑雪辉;王士同;: "基于迁移学习的径向基函数神经网络学习", 计算机工程与应用, no. 05, 19 August 2015 (2015-08-19) * |
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