高炉燃烧料面合成孔径雷达双聚焦成像算法

Dual-focus imaging algorithm of synthetic aperture radar for burning blast furnace burden surface

钢铁生产中的料位和料形是冶炼过程控制的重要指标,基于合成孔径雷达(SAR)原理的微波成像装置可有效提取热态径向料面特征.针对几何形态复杂,回波信号突变性强,甚至会出现遮蔽效应导致雷达失波的料面中心部分,本文建立了中心区域双聚焦测量成像系统.选定炉顶风罩位置对称安装两套雷达,电机控制雷达天线匀速摆动获取二维坐标矩阵,用重采样插值算法将其转换成像素点均匀的矩形灰度图像;根据尺寸参数确定炉心扫描重叠区间,并构建料面中心双聚焦融合算法(DfSAR)拼接双图像.与均值融合相比,图像互信息提高10.43%,清晰度改善23.91%.最后,采用雷达恒虚警率(CFAR)目标检测算法有效滤除高炉内粉尘颗粒物对料面图像的干扰.

The position and shape of the burden surface in ironmaking are important indicators for the control of the smelting process.Microwave imaging device based on the principle of synthetic aperture radar(SAR)effectively extracts radial surface information in the hot state.In the intricate center of burden surface,the echo is mutable and even no echo with the shadowing effect.A dual-focus measurement imaging system for the center area is constructed.Two radars are installed symmetrically at the selected position.The antenna swings with a motor moving in constant speed,and a twodimensional coordinate matrix is obtained by radar,then the matrix is transformed into a rectangular image with uniform pixels by resampling interpolation method.The scanning overlap area is determined according to the actual parameters and a dual-focus SAR algorithm(DfSAR)are designed to stitch images from two radars.Compared with mean fusion,the mutual information is improved by 10.43%and the image definition is improved by 23.91%.Finally,the constant false alarm rate(CFAR)algorithm is used to effectively filter the interference of dust in the blast furnace on the image.