Research On Electro-hydraulic Control System Of Casing Rotator

With the development of city modernization, high-rise buildings, road-bridge and railway construction, large piles of rock-soil drilling and tunneling technology is getting in more extensive application, pile foundation has become one of the most important foundation forms. And with the project of city reconstruction, the demand of eliminating the underground obstacles such as residue of concrete structure or the old pile foundation is getting increasing, too.Casing rotator is an important kind of drilling pile rig with powerful torque and high efficiency, which is getting in more application and mainly used in construction of cast-in-place pile, occlusive piles and underground diaphragm wall, especially in application of clearing away the underground obstacles. It’s steady, vibration-free and has a small disturbance with the soil horizon around the casing while drilling.The drilling hydraulic control system with constant pressure and automatic leveling control system are two key subsystems of casing rotator. The study abroad about drilling control of casing rotator is nearly blank, with little relevant paper and information, and the domestic research is almost confined to introducing the construction method. Based on the work of hydraulic and electrical system design, research and optimization of boring control system and automatic leveling control system are achieved through modeling, simulation and experiment, which can be presented for the research and development to improve the performance of casing rotator.In chapter1, on the basis of referring to associated documents about casing rotator both home and abroad, the status of manufacturing and application as well as the unique advantages were summarized, the meaning and contents of this subject were presented.In chapter2, the hydraulic system of casing rotator was designed and the working principles were described. The key parameters and components were determined by calculating with actual working conditions and functions. In chapter3, the electrical control system of casing rotator was designed. The function, mode and working principle of hardware and software were produced. And the whole PLC control system was developed.In chapter4, the constant pressure boring control system and flow adaptive control system were analyzed. The simplified mathematic models of these two subsystems were established. The simulation models of the mechanical parts were established based on AMESim, and the data calculation control parts were established based on Simulink. Then, simulation analyses were worked out to investigate the dynamic characteristics. The simulation and results showed that the control strategy of constant pressure boring control system and flow adaptive control system can effectively satisfy the dynamic requirements while drilling. Then, the experiment of constant pressure boring control was work out and the results verified the simulation analyses.In chapter5, a simple automatic leveling control system was proposed. The control scheme with one-directional adjustment had been proven to be an appropriate technique to achieve a desired performance by analyses and test results.In chapter6, the major work of study was summarized, the deficiencies and problems in the study were pointed out and the future study of casing rotator was prosprcted.