| Auto-drilling is self-regulating bit pressure,rotate speed and making hole by control system according to the request of drilling techniques but depending on drilling worker in oil drilling operations. Auto-drilling technology experiences two phases: band brake and disk brake. The inside study of auto-drilling is later. At the present, the brake system of a large of drillers are band brake. But the whole system of band brake auto-drilling is very complex and don't ensure its reliability, accuracy and stability because it has a series of air pressure and mechanism equipments. Disk brake auto-drilling adopts hydraulic pressure to control skid force of disk brake directly and is easily to interface with electric signal without transitional taches, so such auto-drilling can realize remote control and automatism operation. Studying and developing automatic driller of disk brake is the trend by and by. That is one reason why this thesis chooses the topic. The studying object of this thesis is the control system of ZJ30DBT produced by the fourth machine shop of jianghan oil department. This thesis completes the design of bit pressure control system. First every taches of it are analyzed in detail. Control system is increased two inner loops—hydraulic pressure loop and speed loop to pick up response,enhance stability improve nonlinearity and advance precision of drawworks. Corresponding measure is made after simulation the model of the two loops and proved well; Second fuzzy theory is used to design bit pressure controller because the system is a time-variant, time-lag and nonlinear system; At last, this thesis solves lag problem of the system with Smith estimate arithmetic. The experiment based on MATLAB by computer shows that the effect of this control mode is very well. At the same time, proportion parameter are made sure. A lot of experiment proves that this method is very efficiency. At last ,bit pressure control arithmetic based on fuzzy theory is compiled.
|
PDF Full Text Request