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超长工作面矿压自适应分区与周期来压时空预测方法

Adaptive zoning and spatiotemporal prediction method of periodic weighting for super-long working face

  • 摘要: 针对超长工作面矿压响应具有明显空间非同步性、矿压信号受强噪声干扰等问题,提出一种融合时空拓扑约束与模态特征重构的超长工作面矿压自适应分区及预测方法。首先,考虑不同位置支架矿压响应在时间演化和空间邻接关系上的差异,采用动态时间规整(Dynamic Time Warping,DTW)度量支架压力序列的时间相似性,引入空间拓扑约束构建矿压时空联合距离模型,并结合K-Medoids聚类实现工作面矿压自适应分区,为区域化矿压建模提供空间拓扑基础。随后,采用冻结频域变分模态分解(Frozen-Frequency Variational Mode Decomposition,FF-VMD)方法,仅利用训练集确定矿压信号频率先验及分解参数,并在测试阶段保持相关参数冻结,实现循环末阻力序列的无数据泄露模态分解与高频噪声抑制。在此基础上,构建区域独立的注意力时空图卷积网络(Attention-based Spatiotemporal Graph Convolutional Networks,AST-GCN),通过图卷积提取区域内支架间空间关联特征,结合时间卷积和注意力机制学习矿压演化的时序依赖关系,对不同模态分量进行联合预测并重构循环末阻力,进一步结合动态区域块判别方法实现周期来压区域的时空重构与识别。结果表明:AST-GCN在重构循环末阻力预测中的平均绝对误差(MAE)为0.59 MPa、均方根误差(RMSE)为0.73 MPa、平均绝对百分比误差(MAPE)为1.47%、决定系数(R2)为0.959 8,预测误差低于长短期记忆网络(Long Short-Term Memory,LSTM)、时空长短期记忆网络(Spatio-Temporal Long Short-Term Memory,ST-LSTM)及时空图卷积网络(Spatial-Temporal Graph Convolutional Network,ST-GCN);基于模态重构结果开展周期来压区域判别后,预测结果与实测数据判别结果之间的F1分数为0.719 4,表明所提方法能够识别复杂矿压条件下周期来压区域的时空分布特征,并在不同地质条件工作面的重新建模验证中表现出较好的适用性。研究表明,该方法能有效表征超长工作面矿压的区域差异、空间关联及时间演化特征,实现周期来压区域的时空预测与识别。

     

    Abstract: To address the pronounced spatial asynchrony of ground-pressure responses and strong noise interference in ground-pressure signals in super-long working faces, an adaptive zoning and prediction method integrating spatiotemporal topological constraints and modal-feature reconstruction is proposed. First, considering the differences in the temporal evolution and spatial adjacency of ground-pressure responses at different support locations, Dynamic Time Warping (DTW) is employed to quantify the temporal similarity between support-pressure sequences. A spatiotemporal joint distance model is then established by incorporating spatial topological constraints, and K-Medoids clustering is used to achieve adaptive zoning of the working face, thereby providing a spatial-topological basis for regionalized ground-pressure modeling. Subsequently, Frozen-Frequency Variational Mode Decomposition (FF-VMD) is adopted, in which the frequency priors and decomposition parameters of the ground-pressure signals are determined exclusively from the training set and kept fixed during testing, enabling leakage-free modal decomposition of end-of-cycle support-resistance sequences while suppressing high-frequency noise. On this basis, independent regional Attention-based Spatiotemporal Graph Convolutional Networks (AST-GCN) are constructed. Graph convolution is used to extract spatial correlations among supports within each region, while temporal convolution and an attention mechanism are employed to learn the temporal dependencies of ground-pressure evolution. The modal components are jointly predicted and subsequently reconstructed to obtain the end-of-cycle support resistance. A dynamic regional-block discrimination method is further introduced to achieve the spatiotemporal reconstruction and identification of periodic weighting regions. The results show that, for reconstructed end-of-cycle support-resistance prediction, AST-GCN achieves a Mean Absolute Error (MAE) of 0.59 MPa, a Root Mean Square Error (RMSE) of 0.73 MPa, a Mean Absolute Percentage Error (MAPE) of 1.47%, and a coefficient of determination (R2) of 0.959 8, with lower prediction errors than Long Short-Term Memory (LSTM), Spatio-Temporal Long Short-Term Memory (ST-LSTM), and Spatial-Temporal Graph Convolutional Network (ST-GCN) models. For periodic weighting region discrimination based on modal reconstruction, the F1-score between the predicted and measured-data-based discrimination results reaches 0.719 4, indicating that the proposed method can identify the spatiotemporal distribution characteristics of periodic weighting regions under complex ground-pressure conditions and demonstrates good applicability when re-established and validated on a working face with different geological conditions. The results demonstrate that the proposed method can characterize the regional differences, spatial correlations, and temporal evolution of ground pressure in super-long working faces, enabling spatiotemporal prediction and identification of periodic weighting regions.

     

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