采煤机的精准定位是实现无人开采的关键，但是现阶段的采煤机定位技术定位精度较低，无法满足高精度定位的要求。为此，提出在综采工作面的两个端头位置分别设置导轨，使超宽带(Ultra-Wideband ,UWB)基站群能沿着导轨整体移动，当采煤机运行到端头时，利用对应端头的UWB定位系统获得采煤机的位置坐标，完成一刀截割之后，UWB基站群沿着进刀方向迁移，为下一次端头定位做好准备，实现“一刀一迁移”的端头定位策略，为惯性导航提供端头校准的依据。考虑到井下实际环境中测量噪声较大，提出了基于最小均方误差准则(Minimum Mean Square Error Criterion, MMSEC)的收缩估计方法；以定位终端与基站群之间的距离构建观测方程，建立扩展卡尔曼滤波(Extended Kalman Filter, EKF)模型，进一步消除距离残差对定位精度的影响，提高UWB定位系统的位置估计精度；以基站群迁移装置和定位终端移动平台为基础，模拟采煤机的运动，研究所提基站群迁移策略和定位算法。试验结果表明，MMSEC收缩估计方法能够提高运动轨迹的定位精度，第4刀和第5刀的定位精度提升比较明显，平均定位误差由0.341 m，0.394 m减小为0.296 m，0.339 m，定位精度分别提升了13.1%和13.9%，经过EKF平滑处理后，第4刀和第5刀的平均定位精度进一步提升13.5%和10.6%；随着基站群迁移次数的增加，平均定位误差逐渐增大，x轴和z轴平均误差逐渐增加，y轴平均误差基本保持在0.2 m之内；MMSEC-EKF算法的前3刀的定位精度小于0.2 m, 因此采煤机完成3次循环截割后，重新测量基站群的坐标，能够获得更好的定位效果；提出的端头“一刀一迁移”的定位策略及定位算法为井下定位技术提供理论参考，该方法有待井下环境的进一步试验验证。

Accurate positioning of the shearer is the key to realize unmanned mining, but the localization accuracy of the shearer is low at present, which cannot satisfy the requirements of high precision positioning. Therefore, we propose that a guide rail should be respectively set up at the end of the fully mechanized mining face so that the Ultra-Wideband (UWB) base station group can move along the guide rail as a whole. When the shearer runs to the end of the fully mechanized mining face, the position coordinates of the shearer are obtained by using the UWB positioning system. After completing the current cutting, the UWB base station group migrate along the feed direction to prepare for the next positioning, achieving the positioning strategy of“one navigation one migration”, which can provide the reference for the calibration of the inertial navigation. Taking into account of the large measurement noise in the underground environment, we propose that the TOA shrinkage estimation method with the minimum mean square error criterion (MMSEC), and the observation equation is constructed based on the distance between the location terminal and the base station group, and then the extended Kalman filter (EKF) model is established to further eliminate the influence of distance residuals on the positioning accuracy and improve the position estimation accuracy of the UWB positioning system. On the basis of base station group migration device and positioning terminal mobile platform, the motion of shearer is simulated to investigate the base station group migration strategy and location algorithm of base station group migration. Experimental results showed that, MMSEC shrinkage estimation method can improve the positioning accuracy of motion trajectory, and the positioning accuracies of the third and four navigation were significantly enhanced, and the average localization errors decreased respectively from 0.341 m, 0.394 m to 0.296, 0.339 m, whose corresponding positioning accuracies were improved by 13.1% and 13.9%, respectively. After the EKF smoothing was implemented, the average positioning accuracies of the third and four navigation were further improved by 13.5% and 10.6%,respectively. As the number of base station migration increased, the average positioning error increased gradually; the average positioning error with respect to both the x and z axes increased gradually, while the average error on the y axis was basically within 0.2 m.Additionally, the positioning accuracy utilizing MMSEC-EKF approach from the first to the third navigation was less than was less than 0.2 m,which indicated that after implementing three cycles cutting, the coordinates of base stations should be re-measured, higher positioning accuracy can be obtained. The proposed positioning strategy and algorithm of “one navigation one migration” at the end of the fully mechanized mining face can provide theoretical reference for underground positioning technology, however, this strategy require to be further certified using the actual experimental verification in the underground coal mine environment.