Drilling trajectory measurement method while drilling for drilling robot forrockburst prevention based on wireless electromagnetic transmission

Drilling robot for rockburst prevention is a necessary equipment for achieving unmanned pressure relief in coal mines with high in-situ stress. Developing a reliable drilling trajectory measurement system while drilling is an important measure to ensure the effectiveness of drilling pressure relief. Based on analysis of basic principle of drilling trajectory measurement while drilling, a drilling trajectory measurement drill rod based on wireless electromagnetic transmission technology is developed. The spectral efficiency and anti-noise performance of different electromagnetic signal modulation methods are analyzed, and the FSK modulation and demodulation process for drill rod attitude signals are designed, so as to develop a weak signal conditioning system that amplifies before filtering. The Corresponding functional circuits are designed and tested using Multisim software, and each circuit module met the design requirements. A comparative analysis is conducted on the accuracy and execution efficiency of five trajectory calculation algorithms, and the mean angle full range method is chosen for drilling trajectory calculation. The vibration error processing method for inertial measurement unit measurement data based on wavelet filtering is studied, and the effectiveness of wavelet filtering algorithm in improving attitude angle calculation accuracy is also verified. A drilling depth measurement method based on wire displacement sensors and robot action markers is proposed, and the surface and underground experiments are conducted. The experimental results show that the designed weak signal conditioning system can achieve the reception and processing of weak signals in underground coal mines. The drilling depth measurement method based on wire displacement sensors and robot action markers can improve the fitting accuracy of the drilling trajectory.