有效且准确的剩余使用寿命预测是可靠且安全使用锂离子电池的关键因素。这项工作训练了长期记忆复发性神经网络模型,以从各个周期和电压下排放能力的顺序数据中学习,并作为在不同条件下循环的电池电池的周期寿命预测器。使用前60-80个周期的实验数据,我们的模型在大约80个样本的测试集上实现了有希望的预测准确性。
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准确估计电池的健康状况(SOH)有助于防止电池供电的应用出乎意料的失败。随着减少新电池模型培训的数据需求的优势,转移学习(TL)是一种有前途的机器学习方法,该方法应用了从源电池中学到的知识,该方法具有大量数据。但是,尽管这些是成功的TL的关键组成部分,但很少讨论源电池模型是否合理以及可以传输的信息的哪一部分的确定。为了应对这些挑战,本文通过利用时间动态来协助转移学习,提出了一种可解释的基于TL的SOH估计方法,该方法由三个部分组成。首先,在动态时间扭曲的帮助下,放电时间序列的时间数据被同步,从而产生了循环同步时间序列的翘曲路径,这些时间序列负责使周期上的容量降解。其次,从周期同步时间序列的空间路径中检索的规范变体用于在源电池和目标电池之间进行分布相似性分析。第三,当分布相似性在预定义的阈值范围内时,通过从源SOH估计模型转移常见的时间动力学来构建一个综合目标SOH估计模型,并用目标电池的残留模型补偿错误。通过广泛使用的开源基准数据集,通过根平方误差评估的提议方法的估计误差高达0.0034,与现有方法相比,准确性提高了77%。
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通过有效的监控和调整电池操作条件,促进了锂离子电池的寿命和安全性。因此,为电池管理系统上的健康状况(SOH)监测提供快速准确的算法至关重要。由于对电池劣化的复杂性和多种因素的复杂性和多种因素的复杂性,特别是因为不同的劣化过程发生在各种时间尺度,并且它们的相互作用发挥着重要作用。数据驱动方法通过用统计或机器学习模型近似复杂进程来绕过这个问题。本文提出了一种数据驱动方法,在电池劣化的背景下,尽管其简单性和易于计算:多变量分数多项式(MFP)回归。模型从一个耗尽的细胞的历史数据训练,并用于预测其他细胞的SOH。数据的特征在于模拟动态操作条件的载荷变化。考虑了两个假设情景:假设最近的容量测量是已知的,则另一个仅基于标称容量。结果表明,在考虑到电池寿命的电池结束时,通过其历史数据的历史数据受到它们的历史数据的影响,电池的降解行为受到其历史数据的影响。此外,我们提供了一种多因素视角,分析了每个不同因素的影响程度。最后,我们与长期内记忆神经网络和其他来自相同数据集的文献的其他作品进行比较。我们得出结论,MFP回归与当代作品有效和竞争,提供了几种额外的优点。在可解释性,恒定性和可实现性方面。
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Remaining Useful Life (RUL) estimation plays a critical role in Prognostics and Health Management (PHM). Traditional machine health maintenance systems are often costly, requiring sufficient prior expertise, and are difficult to fit into highly complex and changing industrial scenarios. With the widespread deployment of sensors on industrial equipment, building the Industrial Internet of Things (IIoT) to interconnect these devices has become an inexorable trend in the development of the digital factory. Using the device's real-time operational data collected by IIoT to get the estimated RUL through the RUL prediction algorithm, the PHM system can develop proactive maintenance measures for the device, thus, reducing maintenance costs and decreasing failure times during operation. This paper carries out research into the remaining useful life prediction model for multi-sensor devices in the IIoT scenario. We investigated the mainstream RUL prediction models and summarized the basic steps of RUL prediction modeling in this scenario. On this basis, a data-driven approach for RUL estimation is proposed in this paper. It employs a Multi-Head Attention Mechanism to fuse the multi-dimensional time-series data output from multiple sensors, in which the attention on features is used to capture the interactions between features and attention on sequences is used to learn the weights of time steps. Then, the Long Short-Term Memory Network is applied to learn the features of time series. We evaluate the proposed model on two benchmark datasets (C-MAPSS and PHM08), and the results demonstrate that it outperforms the state-of-art models. Moreover, through the interpretability of the multi-head attention mechanism, the proposed model can provide a preliminary explanation of engine degradation. Therefore, this approach is promising for predictive maintenance in IIoT scenarios.
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Batteries plays an essential role in modern energy ecosystem and are widely used in daily applications such as cell phones and electric vehicles. For many applications, the health status of batteries plays a critical role in the performance of the system by indicating efficient maintenance and on-time replacement. Directly modeling an individual battery using a computational models based on physical rules can be of low-efficiency, in terms of the difficulties in build such a model and the computational effort of tuning and running it especially on the edge. With the rapid development of sensor technology (to provide more insights into the system) and machine learning (to build capable yet fast model), it is now possible to directly build a data-riven model of the battery health status using the data collected from historical battery data (being possibly local and remote) to predict local battery health status in the future accurately. Nevertheless, most data-driven methods are trained based on the local battery data and lack the ability to extract common properties, such as generations and degradation, in the life span of other remote batteries. In this paper, we utilize a Gaussian process dynamical model (GPDM) to build a data-driven model of battery health status and propose a knowledge transfer method to extract common properties in the life span of all batteries to accurately predict the battery health status with and without features extracted from the local battery. For modern benchmark problems, the proposed method outperform the state-of-the-art methods with significant margins in terms of accuracy and is able to accuracy predict the regeneration process.
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For Prognostics and Health Management (PHM) of Lithium-ion (Li-ion) batteries, many models have been established to characterize their degradation process. The existing empirical or physical models can reveal important information regarding the degradation dynamics. However, there is no general and flexible methods to fuse the information represented by those models. Physics-Informed Neural Network (PINN) is an efficient tool to fuse empirical or physical dynamic models with data-driven models. To take full advantage of various information sources, we propose a model fusion scheme based on PINN. It is implemented by developing a semi-empirical semi-physical Partial Differential Equation (PDE) to model the degradation dynamics of Li-ion-batteries. When there is little prior knowledge about the dynamics, we leverage the data-driven Deep Hidden Physics Model (DeepHPM) to discover the underlying governing dynamic models. The uncovered dynamics information is then fused with that mined by the surrogate neural network in the PINN framework. Moreover, an uncertainty-based adaptive weighting method is employed to balance the multiple learning tasks when training the PINN. The proposed methods are verified on a public dataset of Li-ion Phosphate (LFP)/graphite batteries.
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地震的预测和预测有很长的时间,在某些情况下有肮脏的历史,但是最近的工作重新点燃了基于预警的进步,诱发地震性的危害评估以及对实验室地震的成功预测。在实验室中,摩擦滑移事件为地震和地震周期提供了类似物。 Labquakes是机器学习(ML)的理想目标,因为它们可以在受控条件下以长序列生产。最近的作品表明,ML可以使用断层区的声学排放来预测实验室的几个方面。在这里,我们概括了这些结果,并探索了Labquake预测和自动回归(AR)预测的深度学习(DL)方法。 DL改善了现有的Labquake预测方法。 AR方法允许通过迭代预测在未来的视野中进行预测。我们证明,基于长期任期内存(LSTM)和卷积神经网络的DL模型可以预测在几种条件下实验室,并且可以以忠诚度预测断层区应力,证实声能是断层区应力的指纹。我们还预测了实验室的失败开始(TTSF)和失败结束(TTEF)的时间。有趣的是,在所有地震循环中都可以成功预测TTEF,而TTSF的预测随preseismisic断层蠕变的数量而变化。我们报告了使用三个序列建模框架:LSTM,时间卷积网络和变压器网络预测故障应力演变的AR方法。 AR预测与现有的预测模型不同,该模型仅在特定时间预测目标变量。超出单个地震周期的预测结果有限,但令人鼓舞。我们的ML/DL模型优于最先进的模型,我们的自回归模型代表了一个新颖的框架,可以增强当前的地震预测方法。
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With the evolution of power systems as it is becoming more intelligent and interactive system while increasing in flexibility with a larger penetration of renewable energy sources, demand prediction on a short-term resolution will inevitably become more and more crucial in designing and managing the future grid, especially when it comes to an individual household level. Projecting the demand for electricity for a single energy user, as opposed to the aggregated power consumption of residential load on a wide scale, is difficult because of a considerable number of volatile and uncertain factors. This paper proposes a customized GRU (Gated Recurrent Unit) and Long Short-Term Memory (LSTM) architecture to address this challenging problem. LSTM and GRU are comparatively newer and among the most well-adopted deep learning approaches. The electricity consumption datasets were obtained from individual household smart meters. The comparison shows that the LSTM model performs better for home-level forecasting than alternative prediction techniques-GRU in this case. To compare the NN-based models with contrast to the conventional statistical technique-based model, ARIMA based model was also developed and benchmarked with LSTM and GRU model outcomes in this study to show the performance of the proposed model on the collected time series data.
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作为有关健康状况的重要组成部分,数据驱动的先进健康(SOH)估计已成为锂离子电池(LIBS)的主导地位。为了处理跨电池的数据差异,当前的SOH估计模型参与转移学习(TL),该模型保留通过重复使用离线训练模型的部分结构而获得的APRIORII知识。但是,电池完整生命周期的多种降解模式使追求TL的挑战。引入了阶段的概念来描述呈现出类似降解模式的连续循环的集合。提出了一个可转移的多级SOH估计模型,以在同一阶段跨电池执行TL,由四个步骤组成。首先,有了确定的阶段信息,将来自源电池的原始循环数据重建到具有高尺寸的相空间中,从而探索传感器有限的隐藏动力学。接下来,在每个阶段跨循环的域不变表示是通过与重建数据的循环差异子空间提出的。第三,考虑到不同阶段之间不平衡的放电循环,提出了一个由长期短期存储网络和具有拟议时间胶囊网络的强大模型组成的切换估计策略,以提高估计精度。最后,当目标电池的循环一致性漂移时,更新方案会补偿估计错误。提出的方法在各种传输任务中的竞争算法优于其竞争算法,用于带有三个电池的运营基准测试。
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统计建模和数据驱动学习是吸引许多关注的两个重要领域。统计模型打算捕获和解释变量之间的关系,而基于数据的学习尝试直接从数据中提取信息而无需通过复杂模型预先处理。鉴于两个字段中的广泛研究,一个微妙的问题是如何正确地整合基于数据的方法现有知识或模型。在本文中,基于时间序列数据,我们提出了两种不同的方向来集成两者,基于分解的方法和利用数据特征的统计提取方法。第一个将数据分解成线性稳定,非线性稳定和不稳定部件,其中合适的统计模型用于线性稳定和非线性稳定部件,而适当的机器学习工具用于不稳定部件。第二个应用统计模型来提取数据的统计特征,并将其作为额外的输入送入机器学习平台进行培训。最关键和具有挑战性的是如何从数学或统计模型中确定和提取有价值的信息,以提高机器学习算法的性能。我们使用具有不同程度的稳定性的时间序列数据评估该提案。性能结果表明,两种方法都可以优于使用模型和单独学习的现有方案,而改进可能超过60%。我们所提出的方法都具有促进拓展模型和数据驱动的方案之间的差距,并集成了两个,以提供全面的高等学校性能。
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近年来,在运输电气化方面取得了重大进展。作为主要的储能设备,锂离子电池(LIB)已受到广泛关注。准确地预测健康状况(SOH)不仅可以缓解用户对电池寿命的焦虑,而且还可以为电池管理提供重要信息。本文提出了一种基于视觉变压器(VIT)模型的SOH的预测方法。首先,预定义电压范围的离散充电数据用作输入数据矩阵。然后,电池的循环特征是由VIT捕获的,可以获得可以获得全局特征,并且通过将循环特征与完整连接(FC)层相结合来获得SOH。同时,引入了转移学习(TL),并根据目标任务电池的早期周期数据进一步微调基于源任务电池训练的预测模型,以提供准确的预测。实验表明,与现有的深度学习方法相比,我们的方法可以获得更好的特征表达,从而可以实现更好的预测效果和传递效果。
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Accurate prediction of battery health is essential for real-world system management and lab-based experiment design. However, building a life-prediction model from different cycling conditions is still a challenge. Large lifetime variability results from both cycling conditions and initial manufacturing variability, and this -- along with the limited experimental resources usually available for each cycling condition -- makes data-driven lifetime prediction challenging. Here, a hierarchical Bayesian linear model is proposed for battery life prediction, combining both individual cell features (reflecting manufacturing variability) with population-wide features (reflecting the impact of cycling conditions on the population average). The individual features were collected from the first 100 cycles of data, which is around 5-10% of lifetime. The model is able to predict end of life with a root mean square error of 3.2 days and mean absolute percentage error of 8.6%, measured through 5-fold cross-validation, overperforming the baseline (non-hierarchical) model by around 12-13%.
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最近,已经努力将信号阶段和时机(SPAT)消息标准化。这些消息包含所有信号交叉方法的信号相时机。因此,这些信息可用于有效的运动计划,从而导致更多均匀的交通流量和均匀的速度轮廓。尽管努力为半活化的信号控制系统提供了可靠的预测,但预测完全驱动控制的信号相时仍具有挑战性。本文提出了使用聚合的流量信号和循环检测器数据的时间序列预测框架。我们利用最先进的机器学习模型来预测未来信号阶段的持续时间。线性回归(LR),随机森林(RF)和长期内存(LSTM)神经网络的性能是针对天真基线模型进行评估的。结果基于瑞士苏黎世的全面信号控制系统的经验数据集表明,机器学习模型的表现优于常规预测方法。此外,基于树木的决策模型(例如RF)的表现最佳,其准确性满足实用应用要求。
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REED继电器是功能测试的基本组成部分,与电子产品的成功质量检查密切相关。为了为REED继电器提供准确的剩余使用寿命(RUL)估计,根据以下三个考虑,提出了具有降解模式聚类的混合深度学习网络。首先,对于REED继电器,观察到多种降解行为,因此提供了基于动态的$ K $ -MEANS聚类,以区分彼此的退化模式。其次,尽管适当的功能选择具有重要意义,但很少有研究可以指导选择。提出的方法建议进行操作规则,以实施轻松实施。第三,提出了用于剩余使用寿命估计的神经网络(RULNET),以解决卷积神经网络(CNN)在捕获顺序数据的时间信息中的弱点,该信息在卷积操作的高级特征表示后结合了时间相关能力。通过这种方式,lulnet的三种变体由健康指标,具有自组织地图的功能或具有曲线拟合的功能构建。最终,将提出的混合模型与典型的基线模型(包括CNN和长期记忆网络(LSTM))进行了比较,该模型通过具有两个不同不同降级方式的实用REED继电器数据集进行了比较。两种降解案例的结果表明,所提出的方法在索引均方根误差方面优于CNN和LSTM。
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作为自然现象的地震,历史上不断造成伤害和人类生活的损失。地震预测是任何社会计划的重要方面,可以增加公共准备,并在很大程度上减少损坏。然而,由于地震的随机特征以及实现了地震预测的有效和可靠模型的挑战,迄今为止努力一直不足,需要新的方法来解决这个问题。本文意识到​​这些问题,提出了一种基于注意机制(AM),卷积神经网络(CNN)和双向长短期存储器(BILSTM)模型的新型预测方法,其可以预测数量和最大幅度中国大陆各地区的地震为基于该地区的地震目录。该模型利用LSTM和CNN具有注意机制,以更好地关注有效的地震特性并产生更准确的预测。首先,将零阶保持技术应用于地震数据上的预处理,使得模型的输入数据更适当。其次,为了有效地使用空间信息并减少输入数据的维度,CNN用于捕获地震数据之间的空间依赖性。第三,使用Bi-LSTM层来捕获时间依赖性。第四,引入了AM层以突出其重要的特征来实现更好的预测性能。结果表明,该方法具有比其他预测方法更好的性能和概括能力。
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锂离子电池(LIBS)的数学建模是先进电池管理中的主要挑战。本文提出了两个新的框架,将基于机器的基于机器的模型集成,以实现LIBS的高精度建模。该框架的特征在于通知物理模型的状态信息的机器学习模型,从而实现物理和机器学习之间的深度集成。基于框架,通过将电化学模型和等效电路模型分别与前馈神经网络组合,构造了一系列混合模型。混合模型在结构中相对令人惊讶,可以在广泛的C速率下提供相当大的预测精度,如广泛的模拟和实验所示。该研究进一步扩展以进行衰老感知混合建模,导致杂交模型意识到意识到健康状态以进行预测。实验表明,该模型在整个Lib的循环寿命中具有很高的预测精度。
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剪切应力史控制着液化土壤中的孔隙压力反应。当剪切应力振幅低于峰值先前振幅 - 屏蔽效果时,在循环载荷下的孔隙压力不会增加。许多复杂的本构模型无法捕获在环状液化实验中观察到的屏蔽效应。我们基于LSTM神经网络开发了一个数据驱动的机器学习模型,以捕获循环负荷下土壤的液化反应。LSTM模型对在内华达州的12个实验室循环简单剪切测试中进行了训练,该测试是在经受不同循环简单剪切载荷条件下的宽松和密集的条件下进行的。LSTM模型的特征包括土壤的相对密度和先前的应力病史,以预测孔隙水压反应。LSTM模型考虑了屏蔽和密度效应的三个环状简单测试结果,成功地复制了孔隙压力响应。
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Semiconductor lasers, one of the key components for optical communication systems, have been rapidly evolving to meet the requirements of next generation optical networks with respect to high speed, low power consumption, small form factor etc. However, these demands have brought severe challenges to the semiconductor laser reliability. Therefore, a great deal of attention has been devoted to improving it and thereby ensuring reliable transmission. In this paper, a predictive maintenance framework using machine learning techniques is proposed for real-time heath monitoring and prognosis of semiconductor laser and thus enhancing its reliability. The proposed approach is composed of three stages: i) real-time performance degradation prediction, ii) degradation detection, and iii) remaining useful life (RUL) prediction. First of all, an attention based gated recurrent unit (GRU) model is adopted for real-time prediction of performance degradation. Then, a convolutional autoencoder is used to detect the degradation or abnormal behavior of a laser, given the predicted degradation performance values. Once an abnormal state is detected, a RUL prediction model based on attention-based deep learning is utilized. Afterwards, the estimated RUL is input for decision making and maintenance planning. The proposed framework is validated using experimental data derived from accelerated aging tests conducted for semiconductor tunable lasers. The proposed approach achieves a very good degradation performance prediction capability with a small root mean square error (RMSE) of 0.01, a good anomaly detection accuracy of 94.24% and a better RUL estimation capability compared to the existing ML-based laser RUL prediction models.
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粒子加速器是复杂的设施,可产生大量的结构化数据,并具有明确的优化目标以及精确定义的控制要求。因此,它们自然适合数据驱动的研究方法。来自传感器和监视加速器形式的多元时间序列的数据。在加速器控制和诊断方面,快速的先发制人方法是高度首选的,数据驱动的时间序列预测方法的应用尤其有希望。这篇综述提出了时间序列预测问题,并总结了现有模型,并在各个科学领域的应用中进行了应用。引入了粒子加速器领域中的几次和将来的尝试。预测到粒子加速器的时间序列的应用显示出令人鼓舞的结果和更广泛使用的希望,现有的问题(例如数据一致性和兼容性)已开始解决。
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与液态燃料相比,电动汽车(EV)的广泛采用受到目前能量和功率密度低的电池的限制,并且会随着时间的推移而衰老和性能恶化。因此,在电动汽车生命周期内监视电池电量状态(SOC)和健康状况(SOH)是一个非常相关的问题。这项工作提出了一个电池数字双结构结构,旨在在运行时准确反映电池动力学。为了确保有关非线性现象的高度正确性,数字双胞胎依赖于在电池演化痕迹随时间训练的数据驱动模型中依靠:SOH模型,反复执行以估计最大电池容量的退化和SOC型号的降级,定期重新训练以反映衰老的影响。拟议的数字双结构将在公共数据集上举例说明,以激发其采用并证明其有效性,并具有很高的准确性和推理以及与车载执行兼容的时间。
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