多频雷达融合的顶煤结构精准探测技术

Accurate detection technology of top coal structure using multi-frequency radar fusion

顶煤结构的准确探测是实现综放智能化开采的重要依据,然而我国煤层结构复杂且内部常含多层夹矸,易影响综放智能化开采的水平。为此,提出一种多频雷达融合的顶煤结构精准探测方法,可提高雷达天线探测深度内的浅部探测精度,同时对顶煤内部的结构信息进行解释。主要研究步骤如下:首先,对不同频率的雷达数据进行预处理和空间对齐,建立不同频率雷达数据之间的空间对应关系;其次,利用滑动窗口与小波变换加权融合方法对多频率雷达数据进行处理,根据窗口内各分段小波信号的能量占比确定各频率信号的时变权重值,并引入边缘检测算法来提高小波变换对雷达数据的融合效率,实现多频雷达数据有效融合;最后,根据煤-矸-岩的介电常数差异和电磁波传播的衰减特性,建立顶煤内部回波强度模型,并利用分层识别方法计算出顶煤内部煤-矸-岩之间的界面信息,进而反演出顶煤内部结构(包括顶煤厚度、夹矸厚度及层数、夹矸层间距等)。试验结果表明:所提出的方法能有效地将不同频率雷达数据进行融合,并能有效地探测出顶煤内部结构特征,且顶煤厚度、夹矸厚度和夹矸层间距的探测误差均小于10%。该方法有助于实现顶煤结构的精准探测,为综放智能化开采提供理论技术支撑。

Accurately detecting the structure of top coal is crucial for achieving intelligent fully-mechanized caving mining.However,the complex structure of coal seams in China,often consisting of multiple layers of separated gangue,can significantly impact the effectiveness of fully-mechanized caving mining.To address this challenge,this paper proposes a precise detection method for top coal structure based on multi-frequency radar fusion.This method aims to improve the detection accuracy of the shallow part within the radar antenna's detection depth and interpret the structural information inside the top coal.The main research steps are as follows:Firstly,preprocessing and spatial alignment of radar data of different frequencies are carried out to establish the spatial correspondence between radar data of different frequencies.Secondly,a sliding window and wavelet transform weighted fusion method is employed to process the multi-frequency radar data.The time-varying weight value of each frequency signal is determined based on the energy proportion of each segment wavelet signal in the window.Additionally,an edge detection algorithm is introduced to enhance the fusion efficiency of the wavelet transform to the radar data,thereby achieving effective fusion of the multi-frequency radar data.Finally,taking into account the differences in dielectric constants between coal,gangue,and rock,as well as the attenuation characteristics of electromagnetic wave propagation,an internal echo intensity model of top coal is established.The interface information between coal,gangue,and rock inside the top coal is calculated using a stratified identification method,enabling the inverse interpretation of the internal structure of top coal,including the thickness of top coal,the thickness and number of gangue layers,and the spacing between gangue layers.The test results demonstrate that the proposed method can effectively integrate radar data of different frequencies and accurately detect the internal structural characteristics of top coal.Moreover,the detection errors of the thickness of top coal,the thickness of gangue,and the spacing between gangue layers are all less than 10%.This method enables the accurate detection of top coal structure,providing theoretical and technical support for the intelligent fully-mechanized caving mining.