Robust UWB underground anchor rod drilling positioning method based on factor graph

Abstract

The invention discloses a robust UWB underground anchor rod drilling positioning method based on a factor graph. The method can automatically measure the three-dimensional coordinates of the drillingposition of an anchor rod, and does not need to measure the position of a base station in advance. Specifically, under the framework of the factor graph, an improved Turkey robust kernel-based UWB positioning algorithm is provided, and a label and a base station coordinate are solved together as unknown parameters. According to the algorithm, the natural defect of non-Gaussian noise caused by UWBpositioning through least squares is overcome, and the defect of excessive optimization of a robust kernel function (such as Turkey) is also avoided. Aiming at the characteristic that UWB data is generally greater than a true value due to shielding, only data with relatively large distance measurement is selected to be added into a robust kernel; however, data with small distance measurement is likely to be caused by positioning errors, and the square of the residual error of the data is used as an optimization objective function to carry out optimization solution. Experimental results show that the improved UWB positioning algorithm and positioning equipment based on the Turkey robust kernel can obtain the punching position precision with the precision below 2cm in a non-line-of-sight environment.

Description

technical field [0001] The invention relates to the technical field of downhole anchor drilling positioning, in particular to a robust UWB downhole anchor drilling positioning method based on a factor graph. Background technique [0002] In the excavation construction of the underground roadway in the mine, the support of the roof is of great significance. The use of bolt support is a key technology. The stability of the support directly determines the safety of the underground roadway, which is related to the personal safety of underground workers, and determines the construction efficiency, construction quality and economic benefits of the enterprise. When installing a hanging bolt on the roof of the roadway, it is first necessary to locate the installation position of the bolt, drill a hole, and then install the bolt. However, due to the high height of the roof of the roadway, it is difficult to locate when measuring the position of the bolt hole. It often requires two p...

AI Technical Summary

Problems solved by technology

However, UWB sensors still face some difficulties in using underground. The multipath effect is greatly strengthened in the narrow roadway space, and the signal may be blocked by underground workers or moving vehicles at any time. At this time, the electromagnetic wave propagation speed is far from its propagation speed in the air. , the measured value will have strong non-Gaussian noise

In addition, due to the limited ranging range of the UWB signal, only the punching coordinates of a certain range of areas can be measured each time

Images