Parameter Measurement And Transmission Of The Drill Bit For Horizontal Directional Drilling

Horizontal Directional Drilling (HDD) has became one of the most rapidly developing construction techniques which is widely used in the laying of electricity, communications, gas and water pipelines for its high precision and simple construction site needs.Guidance technology, which is generally composed of underground sensing probe, ground-guidance instrument and remote monitoring equipment, is one of the HDD key technologies. At present, nearly all of the guidance-equipments adopted in China are imported; hence, the main purpose of this thesis is to research the parameter measurements and transmission technique of the drill bit for HDD.According to the characteristics of HDD, the measurement of the inclination angle generated from the tilting angle sensor and the traditional acceleration sensor has been researched, and the clockface angle measurement based on photoelectric sensor and photoelectric-roll-ball sensor has been analyzed, then the latest MEMS acceleration sensor was chose to construct measurement system. In term of the measurement system position in the drill bit, the coordinate system was established, measurement model was proposed, and the inclination angle and the clockface angle were measured by MEMS sensors. If the temperature of the drill bit is too high, it would influence the accuracy and even cause permanent damage, thus, the temperature was monitored by integrated temperature sensor in this system.MEMS accelerometer sensors can be classified into uniaxial accelerometer sensor, biaxial accelerometer sensor and triaxial accelerometer sensor. In this thesis, triaxial accelerometer sensor and biaxial acceleration sensor were adopted to measure the inclination angle and the clockface angle of the drill bit; while analog and digital integrated temperature sensor were used to monitor the drill bit temperature. An embedded system has been developed using C8051F single-chip, which can measure the inclination angle, the clockface angle, temperature, and power of the drill bit, and can also meet the measurement requirements with small in size. Data measured underground is needed to transmit to the ground in order that the operator can get the status of the drill bit in real-time. Therefore, the technique of the transmission between underground sensing probe and ground-receiver was researched, and a methodology was proposed combing the wire transmission with the wireless transmission: the wire transmission based on RS-485 was adopted between underground sensing probe and ground-guidance instrument; and when there is a long distance between ground-guidance instrument and remote monitoring equipment, the wire transmission based on RS-485 was used, or the wireless transmission was adopted.Two human-computer interfaces have been designed with Liquid Crystal Display to display the data of the drill bit, and a graphical display interface, which can be more friendly and intuitive based on PC by using VB programming, has been developed.