China Mechanical Engineering ›› 2025, Vol. 36 ›› Issue (8): 1864-1874.DOI: 10.3969/j.issn.1004-132X.2025.08.021
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Congbo LI(
), Hewang ZHAI, Wei WU(
), Ke DONG, Xiangfei ZHANG
Received:2024-02-27
Online:2025-08-25
Published:2025-09-18
Contact:
Wei WU
通讯作者:
吴畏
作者简介:李聪波,男,1981年生,教授、博士研究生导师。研究方向为绿色制造与智能制造。E-mail:congboli@cqu.edu.cn。
基金资助:CLC Number:
Congbo LI, Hewang ZHAI, Wei WU, Ke DONG, Xiangfei ZHANG. Energy Consumption Anomaly Detection of Automobile Painting Drying System Based on TCN-GAT and Hybrid Neural Network[J]. China Mechanical Engineering, 2025, 36(8): 1864-1874.
李聪波, 翟贺旺, 吴畏, 董可, 张祥飞. 基于TCN-GAT与混合神经网络的汽车涂装烘干系统能耗异常检测[J]. 中国机械工程, 2025, 36(8): 1864-1874.
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URL: https://www.cmemo.org.cn/EN/10.3969/j.issn.1004-132X.2025.08.021
| 设备型号 | 采集参数 | 单位 | 2023⁃09⁃01 00∶00 | 2023⁃09⁃01 00∶15 | … | 2023⁃11⁃30 23∶45 |
|---|---|---|---|---|---|---|
| 生产环境温度t0 | ℃ | 28.1633 | 28.1013 | … | 17.1458 | |
| P1E1T1WU301 | 加热区WU301热交换箱温度t1 | ℃ | 87.7268 | 84.3041 | … | 92.4576 |
| 加热区WU301热交换箱压力p1 | Pa | 985.7992 | 941.4691 | … | 945.8357 | |
| P1E1T1WU305 | 加热区WU305热交换箱温度t2 | ℃ | 91.8505 | 88.0155 | … | 95.1895 |
| 加热区WU305热交换箱压力p2 | Pa | 871.3763 | 827.7887 | … | 799.8168 | |
| P1E1T1WU311 | 加热区WU311热交换箱温度t3 | ℃ | 202.4742 | 194.2268 | … | 201.5335 |
| 加热区WU311热交换箱压力p3 | Pa | 1139.1655 | 1087.9481 | … | 1050.1522 | |
| P1E1T1WU312 | 加热区WU312热交换箱温度t4 | ℃ | 209.7732 | 201.1959 | … | 199.8039 |
| 加热区WU312热交换箱压力p4 | Pa | 859.7018 | 901.0312 | … | 852.8688 | |
| P1E1T1WU321 | 保温区WU321热交换箱温度t5 | ℃ | 205.8415 | 200.3581 | … | 201.0850 |
| 保温区WU321热交换箱压力p5 | Pa | 846.2278 | 841.8042 | … | 854.8539 | |
| P1E1T1WU322 | 保温区WU322热交换箱温度t6 | ℃ | 210.7216 | 201.6495 | … | 200.9524 |
| 保温区WU322热交换箱压力p6 | Pa | 995.0804 | 950.4124 | … | 912.7543 | |
| P1E1T1WT330 | 新风换热热交换箱出口温度t7 | ℃ | 192.4147 | 184.2268 | … | 167.1398 |
| 新风换热热交换箱出口压力p7 | Pa | 1989.4853 | 1974.5362 | … | 1946.1635 | |
| P1E1T1WT706 | 天然气流量V | m3/h | 206.7545 | 199.2641 | … | 198.3837 |
| P1E1T1 | 烘干系统总电流I | A | 695.3133 | 689.1621 | … | 230.9267 |
| 烘干系统总功率P | kW | 373.1522 | 166.5457 | … | 25.2675 | |
| 烘干系统产量Q | 辆 | 7 | 8 | … | 2 | |
| 烘干系统综合能耗E | kgce | 92.1247 | 88.5453 | … | 36.8854 |
Tab.1 The collection parameters of drying system
| 设备型号 | 采集参数 | 单位 | 2023⁃09⁃01 00∶00 | 2023⁃09⁃01 00∶15 | … | 2023⁃11⁃30 23∶45 |
|---|---|---|---|---|---|---|
| 生产环境温度t0 | ℃ | 28.1633 | 28.1013 | … | 17.1458 | |
| P1E1T1WU301 | 加热区WU301热交换箱温度t1 | ℃ | 87.7268 | 84.3041 | … | 92.4576 |
| 加热区WU301热交换箱压力p1 | Pa | 985.7992 | 941.4691 | … | 945.8357 | |
| P1E1T1WU305 | 加热区WU305热交换箱温度t2 | ℃ | 91.8505 | 88.0155 | … | 95.1895 |
| 加热区WU305热交换箱压力p2 | Pa | 871.3763 | 827.7887 | … | 799.8168 | |
| P1E1T1WU311 | 加热区WU311热交换箱温度t3 | ℃ | 202.4742 | 194.2268 | … | 201.5335 |
| 加热区WU311热交换箱压力p3 | Pa | 1139.1655 | 1087.9481 | … | 1050.1522 | |
| P1E1T1WU312 | 加热区WU312热交换箱温度t4 | ℃ | 209.7732 | 201.1959 | … | 199.8039 |
| 加热区WU312热交换箱压力p4 | Pa | 859.7018 | 901.0312 | … | 852.8688 | |
| P1E1T1WU321 | 保温区WU321热交换箱温度t5 | ℃ | 205.8415 | 200.3581 | … | 201.0850 |
| 保温区WU321热交换箱压力p5 | Pa | 846.2278 | 841.8042 | … | 854.8539 | |
| P1E1T1WU322 | 保温区WU322热交换箱温度t6 | ℃ | 210.7216 | 201.6495 | … | 200.9524 |
| 保温区WU322热交换箱压力p6 | Pa | 995.0804 | 950.4124 | … | 912.7543 | |
| P1E1T1WT330 | 新风换热热交换箱出口温度t7 | ℃ | 192.4147 | 184.2268 | … | 167.1398 |
| 新风换热热交换箱出口压力p7 | Pa | 1989.4853 | 1974.5362 | … | 1946.1635 | |
| P1E1T1WT706 | 天然气流量V | m3/h | 206.7545 | 199.2641 | … | 198.3837 |
| P1E1T1 | 烘干系统总电流I | A | 695.3133 | 689.1621 | … | 230.9267 |
| 烘干系统总功率P | kW | 373.1522 | 166.5457 | … | 25.2675 | |
| 烘干系统产量Q | 辆 | 7 | 8 | … | 2 | |
| 烘干系统综合能耗E | kgce | 92.1247 | 88.5453 | … | 36.8854 |
| 数据集 | 正常数据/条 | 数据占比/ % | 异常数据/条 | 数据占比/ % |
|---|---|---|---|---|
| 训练集 | 7378 | 100 | 0 | 0 |
| 测试集1 | 672 | 97.0 | 20 | 3.0 |
| 测试集2 | 672 | 93.6 | 43 | 6.4 |
Tab.2 Anomaly detection dataset information
| 数据集 | 正常数据/条 | 数据占比/ % | 异常数据/条 | 数据占比/ % |
|---|---|---|---|---|
| 训练集 | 7378 | 100 | 0 | 0 |
| 测试集1 | 672 | 97.0 | 20 | 3.0 |
| 测试集2 | 672 | 93.6 | 43 | 6.4 |
| 模型 | 超参数 | 数值 |
|---|---|---|
| TCN | TCN网络数量 时间卷积模块数量 | 3 3 |
| 卷积核大小 | 3,5,7 | |
| 隐藏层通道数量 | [32,64,32] | |
| 激活函数 | ReLU | |
| 时间特征融合网络 | 平均池化层窗口大小 | 3×3 |
| 步幅 | 3 | |
| 全连接层 | [32,16] | |
| GAT | 节点数目 | 20 |
| 注意力头数 | 4 | |
| 激活函数 | LeakyReLU | |
| 节点特征维度 | 15 | |
| 融合网络 | 全连接层 | [32, 16, 8] |
Tab.3 Super parameter setting of the model
| 模型 | 超参数 | 数值 |
|---|---|---|
| TCN | TCN网络数量 时间卷积模块数量 | 3 3 |
| 卷积核大小 | 3,5,7 | |
| 隐藏层通道数量 | [32,64,32] | |
| 激活函数 | ReLU | |
| 时间特征融合网络 | 平均池化层窗口大小 | 3×3 |
| 步幅 | 3 | |
| 全连接层 | [32,16] | |
| GAT | 节点数目 | 20 |
| 注意力头数 | 4 | |
| 激活函数 | LeakyReLU | |
| 节点特征维度 | 15 | |
| 融合网络 | 全连接层 | [32, 16, 8] |
| 数据集 | 训练集占比/% | 精确率 | 召回率 | F1-score |
|---|---|---|---|---|
| 测试集1 | 60 | 0.8840 | 0.8910 | 0.8875 |
| 70 | 0.8915 | 0.8961 | 0.8938 | |
| 80 | 0.9215 | 0.8984 | 0.9098 | |
| 90 | 0.9417 | 0.9242 | 0.9329 | |
| 100 | 0.9764 | 0.9522 | 0.9641 | |
| 测试集2 | 60 | 0.8474 | 0.8714 | 0.8592 |
| 70 | 0.8855 | 0.8925 | 0.8890 | |
| 80 | 0.9018 | 0.9284 | 0.9149 | |
| 90 | 0.9178 | 0.9202 | 0.9190 | |
| 100 | 0.9512 | 0.9635 | 0.9573 |
Tab.4 The anomaly detection results of the training set
| 数据集 | 训练集占比/% | 精确率 | 召回率 | F1-score |
|---|---|---|---|---|
| 测试集1 | 60 | 0.8840 | 0.8910 | 0.8875 |
| 70 | 0.8915 | 0.8961 | 0.8938 | |
| 80 | 0.9215 | 0.8984 | 0.9098 | |
| 90 | 0.9417 | 0.9242 | 0.9329 | |
| 100 | 0.9764 | 0.9522 | 0.9641 | |
| 测试集2 | 60 | 0.8474 | 0.8714 | 0.8592 |
| 70 | 0.8855 | 0.8925 | 0.8890 | |
| 80 | 0.9018 | 0.9284 | 0.9149 | |
| 90 | 0.9178 | 0.9202 | 0.9190 | |
| 100 | 0.9512 | 0.9635 | 0.9573 |
| 超参数 | 模型 | |||
|---|---|---|---|---|
| VAE | GAN | OC-CNN | LSTM | |
| 网络层数 | 3(编码器) | 3(生成器) | 4(卷积层) | 4(LSTM) |
| 3(解码器) | 2(判别器) | |||
| 学习率 | 0.001 | 0.001 | 0.001 | 0.001 |
| 迭代次数 | 800 | 800 | 800 | 800 |
| 批次大小 | 32 | 32 | 32 | 32 |
| 输入维度 | 9 | 9 | 8 | 8 |
| 输出维度 | 9 | 9 | 1 | 1 |
| 激活函数 | Tanh | ReLU | ReLU | ReLU |
| 隐藏层大小 | 32,64,32 | 32,64,32 | 32,64,32 | 32,64,32 |
Tab.5 The algorithm hyperparameter settings
| 超参数 | 模型 | |||
|---|---|---|---|---|
| VAE | GAN | OC-CNN | LSTM | |
| 网络层数 | 3(编码器) | 3(生成器) | 4(卷积层) | 4(LSTM) |
| 3(解码器) | 2(判别器) | |||
| 学习率 | 0.001 | 0.001 | 0.001 | 0.001 |
| 迭代次数 | 800 | 800 | 800 | 800 |
| 批次大小 | 32 | 32 | 32 | 32 |
| 输入维度 | 9 | 9 | 8 | 8 |
| 输出维度 | 9 | 9 | 1 | 1 |
| 激活函数 | Tanh | ReLU | ReLU | ReLU |
| 隐藏层大小 | 32,64,32 | 32,64,32 | 32,64,32 | 32,64,32 |
| 数据集 | 模型 | 指标 | ||
|---|---|---|---|---|
| 精确率 | 召回率 | F1-score | ||
| 测试集1 | VAE | 0.9012 | 0.9133 | 0.9072 |
| GAN | 0.8807 | 0.8835 | 0.8821 | |
| OC-CNN | 0.9415 | 0.9338 | 0.9376 | |
| LSTM | 0.9248 | 0.9214 | 0.9231 | |
| 本文模型 | 0.9764 | 0.9522 | 0.9641 | |
| 测试集2 | VAE | 0.8998 | 0.9024 | 0.9011 |
| GAN | 0.8798 | 0.8994 | 0.8895 | |
| OC-CNN | 0.9608 | 0.9211 | 0.9405 | |
| LSTM | 0.9555 | 0.8791 | 0.9157 | |
| 本文模型 | 0.9512 | 0.9635 | 0.9573 | |
Tab.6 The algorithm comparison results
| 数据集 | 模型 | 指标 | ||
|---|---|---|---|---|
| 精确率 | 召回率 | F1-score | ||
| 测试集1 | VAE | 0.9012 | 0.9133 | 0.9072 |
| GAN | 0.8807 | 0.8835 | 0.8821 | |
| OC-CNN | 0.9415 | 0.9338 | 0.9376 | |
| LSTM | 0.9248 | 0.9214 | 0.9231 | |
| 本文模型 | 0.9764 | 0.9522 | 0.9641 | |
| 测试集2 | VAE | 0.8998 | 0.9024 | 0.9011 |
| GAN | 0.8798 | 0.8994 | 0.8895 | |
| OC-CNN | 0.9608 | 0.9211 | 0.9405 | |
| LSTM | 0.9555 | 0.8791 | 0.9157 | |
| 本文模型 | 0.9512 | 0.9635 | 0.9573 | |
| 数据集 | 模型 | 精确率 | 召回率 | F1-score |
|---|---|---|---|---|
| 测试集1 | V1 | 0.8741 | 0.8978 | 0.8858 |
| V2 | 0.8638 | 0.8676 | 0.8657 | |
| V3 | 0.8447 | 0.7880 | 0.8154 | |
| V4 | 0.9407 | 0.9231 | 0.9318 | |
| V5 | 0.9211 | 0.9243 | 0.9227 | |
| 本文模型 | 0.9764 | 0.9522 | 0.9641 | |
| 测试集2 | V1 | 0.8467 | 0.8147 | 0.8304 |
| V2 | 0.8517 | 0.8452 | 0.8484 | |
| V3 | 0.8348 | 0.7967 | 0.8153 | |
| V4 | 0.9350 | 0.9274 | 0.9312 | |
| V5 | 0.9167 | 0.9434 | 0.9299 | |
| 本文模型 | 0.9512 | 0.9635 | 0.9573 |
Tab.7 The result of ablation experiment
| 数据集 | 模型 | 精确率 | 召回率 | F1-score |
|---|---|---|---|---|
| 测试集1 | V1 | 0.8741 | 0.8978 | 0.8858 |
| V2 | 0.8638 | 0.8676 | 0.8657 | |
| V3 | 0.8447 | 0.7880 | 0.8154 | |
| V4 | 0.9407 | 0.9231 | 0.9318 | |
| V5 | 0.9211 | 0.9243 | 0.9227 | |
| 本文模型 | 0.9764 | 0.9522 | 0.9641 | |
| 测试集2 | V1 | 0.8467 | 0.8147 | 0.8304 |
| V2 | 0.8517 | 0.8452 | 0.8484 | |
| V3 | 0.8348 | 0.7967 | 0.8153 | |
| V4 | 0.9350 | 0.9274 | 0.9312 | |
| V5 | 0.9167 | 0.9434 | 0.9299 | |
| 本文模型 | 0.9512 | 0.9635 | 0.9573 |
| [1] | ZHAO Fuquan, LIU Xinglong, ZHANG Haoyi, et al. Automobile Industry under China's Carbon Peaking and Carbon Neutrality Goals: Challenges, Opportunities, and Coping Strategies[J]. Journal of Advanced Transportation, 2022, 2022(1): 5834707. |
| [2] | GIAMPIERI A, MA Zhiwei, LING-CHIN J, et al. A Techno-economic Evaluation of Low-grade Excess Heat Recovery and Liquid Desiccant-based Temperature and Humidity Control in Automotive Paint Shops[J]. Energy Conversion and Management, 2022, 261: 115654. |
| [3] | GIAMPIERI A, LING-CHIN J, MA Z, et al. A Review of the Current Automotive Manufacturing Practice from an Energy Perspective[J]. Applied Energy, 2020, 261: 114074. |
| [4] | PANG Guansong, SHEN Chunhua, CAO Longbing, et al. Deep Learning for Anomaly Detection: a Review[J]. ACM Computing Surveys, 2021, 54(2): 1-38. |
| [5] | SIMMINI F, RAMPAZZO M, PETERLE F, et al. A Self-tuning KPCA-based Approach to Fault Detection in Chiller Systems[J]. IEEE Transactions on Control Systems Technology, 2022, 30(4): 1359-1374. |
| [6] | YIN Sihua, YANG Haidong, XU Kangkang, et al. Dynamic Real-time Abnormal Energy Consumption Detection and Energy Efficiency Optimization Analysis Considering Uncertainty[J]. Applied Energy, 2022, 307: 118314. |
| [7] | JIN Feng, WU Hao, LIU Yang, et al. Varying-scale HCA-DBSCAN-based Anomaly Detection Method for Multi-dimensional Energy Data in Steel Industry[J]. Information Sciences, 2023, 647: 119479. |
| [8] | SØNDERGAARD H A N, SHAKER H R, JØRGENSEN B N. Automated and Real-time Anomaly Indexing for District Heating Maintenance Decision Support System[J]. Applied Thermal Engineering, 2023, 233: 120964. |
| [9] | 李熙, 张立成. 针对时间序列的城轨牵引能耗异常分析[J]. 北京交通大学学报, 2021, 45(5): 30-36. |
| LI Xi, ZHANG Licheng. Outlier Analysis of Urban Rail Traction Energy Consumption Based on Time Series[J]. Journal of Beijing Jiaotong University, 2021, 45(5): 30-36. | |
| [10] | HUNDMAN K, CONSTANTINOU V, LAPORTE C, et al. Detecting Spacecraft Anomalies Using LSTMS and Nonparametric Dynamic Thresholding[C]∥Proceedings of the 24th ACM SIGKDD International Conference on Knowledge Discovery & Data Mining. London, 2018: 387-395. |
| [11] | DING Nan, GAO Huanbo, BU Hongyu, et al. RADM: Real-time Anomaly Detection in Multivariate Time Series Based on Bayesian Network[C]∥2018 IEEE International Conference on Smart Internet of Things (SmartIoT). Xi'an, 2018: 129-134. |
| [12] | CHEN Zekai, CHEN Dingshuo, ZHANG Xiao, et al. Learning Graph Structures with Transformer for Multivariate Time-series Anomaly Detection in IoT[J]. IEEE Internet of Things Journal, 2022, 9(12): 9179-9189. |
| [13] | ZHAO Hongshan, LIU Huihai, HU Wenjing, et al. Anomaly Detection and Fault Analysis of Wind Turbine Components Based on Deep Learning Network[J]. Renewable Energy, 2018, 127: 825-834. |
| [14] | ZHANG Hongwei, XIA Yuanqing, YAN Tijin, et al. Unsupervised Anomaly Detection in Multivariate Time Series through Transformer-based Variational Autoencoder[C]∥2021 33rd Chinese Control and Decision Conference(CCDC). Kunming, 2021: 281-286. |
| [15] | SONG Ge, HONG S H, KYZER T, et al. Energy Consumption Auditing Based on a Generative Adversarial Network for Anomaly Detection of Robotic Manipulators[J]. Future Generation Computer Systems, 2023, 149: 376-389. |
| [16] | LINANDER H, BALABANOV O, YANG H, et al. Looking at the Posterior: Accuracy and Uncertainty of Neural-network Predictions[J]. Machine Learning: Science and Technology, 2023, 4(4): 045032. |
| [17] | IQBAL T, QURESHI S. Reconstruction Probability-based Anomaly Detection Using Variational Auto-encoders[J]. International Journal of Computers and Applications, 2023, 45(3):231-237. |
| [18] | SUN Changcheng, HE Zhiwei, LIN Huipin, et al. Anomaly Detection of Power Battery Pack Using Gated Recurrent Units Based Variational Autoencoder[J]. Applied Soft Computing, 2023, 132: 109903. |
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