Trenchless Horizontal Directional Drilling Trajectory Measurement Technique

Nowadays, with the rising and development of Trenchless Technology, Horizontal Directional Drilling Technology (abbr. HDD) has become widely used in a variety of underground applications. Accordingly the need for track measurement is in great demand. In this dissertation, the theory and key technologies to measure the track of HDD are studied. The main research concerns on the following lists.1. Firstly, the existing theory and methods for attitude measurement are presented. Based on this, we have designed unique pitch and roll sensors. Besides, the principle of azimuth measurement is studied.2. The theories and methods for sonde depth detection are studied. On the basis of this, a compensation approach with two horizontal aerials is proposed, which use a locator to determine the sonde depth by detecting long wave transmitted from underground. Furthermore, we use analog signal processing and digital signal processing methods to enhance the SNR. so as to increase the measurement accuracy.3. The digital communication of Measuring While Drilling(abbr. MWD) is discussed. The communication used VLF electromagnetic wave is realized. Besides, two applied techniques for synchronization are introduced.4. With the idea of modularization design, we use advanced DSP technology to design the hardware platform of each part of the system with high quality of low-power, reliability, high accuracy and stabilization.Based on the HDD track measuring experimental system and computer simulation, a lot of experiments have been done to verify the methods mentioned above. The results indicate that many key technological problems are solved and such methods are correct, efficient and valuable in practical engineering.