高级检索+

基于EMD-LSTM-Attention的蛋鸡舍环境温度预测

Prediction of environmental temperature in laying hen houses using EMD-LSTM-Attention model

  • 摘要: 针对蛋鸡舍环境温度序列中存在的非线性特征和多尺度动态变化问题,该研究构建了一种融合经验模态分解(empirical mode decomposition,EMD)、长短期记忆网络(long short-term memory,LSTM)与注意力(Attention)机制的EMD-LSTM-Attention模型。该模型首先利用EMD将原始温度时间序列分解为多个本征模态函数,并将各分量作为多通道输入引入LSTM-Attention网络,以增强模型对不同时间尺度特征的表征能力。基于蛋鸡舍全年环境温度数据,在统一试验条件下,将所提出模型与多种主流时序模型进行了对比评估,并系统分析了输入序列长度和预测时长对模型性能的影响。结果表明,在输入序列长度为4.0 h、预测间隔为10.0 min的条件下,EMD-LSTM-Attention模型在全年测试集上的平均绝对误差(mean absolute percentage error,MAPE)为1.43%,均方根误差(root mean squared error,RMSE)为0.291 ℃,决定系数(R2)为0.952,整体性能优于各对比模型。该模型在春、夏、秋、冬各季节数据集上均保持较低预测误差,表现出良好的稳定性。参数敏感性分析表明,在该研究测试范围内,当历史输入窗口为1.0 h时,模型预测误差进一步降低,相较于4.0 h输入窗口,全年MAPE由1.43%降至0.76%。随着预测时长由0.5 h延长至2.5 h,模型误差整体呈上升趋势,但仍保持较高预测精度。该研究结果表明,EMD与深度学习模型的有效结合能够提升蛋鸡舍环境温度短期预测的准确性与稳定性,可为预测型智能环境调控系统的开发提供方法支持。

     

    Abstract: Accurate short-term prediction of indoor air temperature can often dominate the intelligent and proactive environmental control in modern laying hen houses. However, the thermal environment inside poultry facilities is generally governed by complex dynamics with pronounced nonlinearity, non-stationarity, and multi-scale temporal characteristics. However, conventional statistical models and standard deep learning have confined to the relatively slow-varying or rapid fluctuations during operations and environmental control equipment, such as the diurnal and seasonal cycles. The significant challenges are also the struggle to simultaneously capture the long- and short-term variations in the agricultural environmental time series. In this study, a hybrid temperature prediction framework was proposed to integrate the Empirical Mode Decomposition (EMD), Long Short-Term Memory (LSTM) networks, and an attention mechanism, termed the EMD-LSTM-Attention model. The representation and deep learning of the multi-scale temporal features were enhanced in the temperature data of the laying hen house. Specifically, the EMD was first employed as an adaptive signal decomposition. The original non-stationary temperature time series were decomposed into a finite number of intrinsic mode functions (IMFs). Each oscillatory component corresponded to different characteristic time scales. These IMFs were then treated as multi-channel inputs and fed into an LSTM-based prediction network equipped with an attention mechanism, learn temporal dependencies in each decomposed component. The greater importance was dynamically allocated to more informative historical-time steps during prediction. The continuous indoor temperature data were collected from a commercial laying hen house over an entire year, with the measurements at 10-minute intervals. The model robustness was examined under different seasonal conditions. The dataset was organized into five independent but temporally continuous subsets: full-year, spring, summer, autumn, and winter. A chronological split was applied in each dataset, thus allocating 60% of the data for training, 20% for validation, and 20% for testing. All models were trained under identical experimental settings using the Adam optimizer. An early stopping strategy was used to reduce the overfitting. The performance was assessed using three widely adopted evaluation metrics: mean absolute percentage error (MAPE), root mean squared error (RMSE), and the coefficient of determination (R2). The EMD-LSTM-Attention model was evaluated with multiple benchmarks, including the conventional autoregressive (AR) models and several commonly-used deep learning architectures, such as the RNN, GRU, BiGRU, BiLSTM, and Transformer. In addition, ablation experiments were conducted to quantify the contributions of the EMD and attention modules. The results demonstrate that the EMD-LSTM-Attention model consistently outperformed the benchmark models over all datasets. The better performance was achieved in a full-year MAPE of 1.43%, an RMSE of 0.291 °C, and an R² of 0.952 under the default experimental configuration, with an input sequence length of 4 h and a prediction interval of 10 min. The superior prediction accuracy was also compared with the baseline. Furthermore, the relatively low prediction errors were obtained in the spring, summer, autumn, and winter datasets, indicating the stable performance under varying seasonal thermal conditions. A parameter sensitivity analysis was conducted to investigate the influence of key input settings on the model performance. The lowest prediction error was achieved in the range of input sequence lengths using a 1.0 h historical input window. The full-year MAPE decreased from 1.43% (with a 4.0 h input window) to 0.76% under this configuration. Additionally, the impact of the prediction horizon was examined to extend the forecast length from 0.5 to 2.5 h. The model errors also exhibited an overall upward trend, as the prediction horizon increased; Nevertheless, the prediction accuracy remained at a relatively high level in the tested range. Overall, the findings. The signal decomposition with deep learning models substantially enhanced the accuracy and robustness of the short-term temperature prediction in the laying hen houses. The EMD-LSTM-Attention framework can provide a viable data-driven solution to capture complex thermal dynamics. The practical support can also be offered for the predictive and intelligent environmental control in poultry production. The additional environmental variables can be incorporated to further improve the model generalization and applicability over multiple housing facilities.

     

/

返回文章
返回