Research Of The Guiding And Positioning Technology In The Trenchless Horizontal Derectional Drilling

In recent years, the trenchless horizontal directional drilling technology is widelyused in laying, repairing and replacing of pipelines such as communication cables,electricity cables, water pipes, gas pipes and other underground pipelines. It caneffectively improve the efficiency of construction and has small impact on traffic andenvironment.Guiding and positioning technology is one of the key technologies of trenchlesshorizontal directional drilling. At present, the market of the guiding and positioninginstruments market is monopolized by foreign products in China. The high price leads tothe technology can’t be widely used in China. The thesis researches the guiding andpositioning technology of trenchless horizontal directional drilling. The main contents arerepresented as follows:Firstly, according to the methods to measure the posture of the object the thesisresearches a method to measure the drilling tool’s posture which is based on earth’sgravitational field and geomagnetic field. The formula and measurement model of tiltangle, face angle and azimuth angle is proposed by establishing geographical coordinatessystem and the drilling tool coordinate system. The thesis researches the calculationmethod of drilling trajectory by using the posture of drilling tool.Secondly，the thesis designs the measurement circuit system based on STM32and thenewest MEMS sensor. The internal structure of the MEMS sensor and the measurementprinciple of accelerometers and magnetometers are studied. The system measures thetemperature of the drilling tool in order to ensure the nomal working of the devices. Thethesis designs a display interface based on PC by using VC++6.0to disply the posture ofdrilling tool so that the driller can grasp the posture of drilling tool more graphical. Theexperiment of measuring tool posture by three axis platform and the measuring circuit hasbeen done and the thesis analyses the data of the result. The result is displayed by LCDand PC. The thesis proposes a method for measuring the azimuth angle in the case ofmagnetic anomalies.Finally，The driller can get the status of the drilling tool in real-time by data information of the drilling tool’s posture measured underground and adjust the drillingtool timely. Therefore, the technology of the transmission between undergroundmeasuring system and ground-receiver was researched, and a data transmission scheme isproposed which is based on low-voltage power line carrier communication.The feasibilitysof the cheme is verified by simulations.