| In recent years, with the rapid growth of the global economy, especially in theasia-pacific region including China, the increase of the demand for oil makes the originalshort of oil and gap supplies further increase, the supply and demand of oil and gas resourcesgoes imbalance and oil price continues rising. Chinese technology and equipment of oil’sexploration and development as the important support of petroleum resource’s mining,urgently needs to keep up with and surpass the advanced level of world. At present, thecompetition of oil industry is becoming fiercer, so that it is imperative to reduce the cost of oilmining and shorten the cycle of oil development and it is very important to design a new typeof oil drilling rig and control system.The the most important part of drilling equipment technology is automatic feed drillingsystem, which not only can improve drilling efficiency well, but also can reduce the drillingcost and driller labor’s intensity greatly. At present, the domestic manufacturers of automaticfeed drilling control system use the traditional PID algorithm to calculate the drill speed torealize the closed-loop control of drill speed through controlling frequency converter. Whenlayer changes, the parameters of automatic feed drilling system need adjusting manuallyaccording to the formation, which makes the system’s operation complex, maintenanceperformance poor and adaptability poor. Simple fuzzy controller is not very good, because ofits output slow response and big residual error. However, the linear PID controller not onlycan makes the control system to get a high precision and speed up the dynamic response.Considering the controlled object time-varying, large time-delay, high nonlinear and thedifficult establishment of precise mathematical model so on problems, after researching theworking principle of automatic feed drilling system with the AC frequency conversion and therelationship between the factors of affecting drilling, Fuzzy PID control with adaptiveparameters is applied in the automatic feed drilling. The MATLAB simulation shows that thesystem can realize learning oneself online and adjusting parameters on real-time and improverapidity, adaptability and robustness of the control system and has high precision.Through researching the working principle and process, relevant control methods andalgorithms of automatic feed drilling system thoroughly, using the technology of Fuzzy PIDcontrol with adaptive parameter to control the automatic feed drilling, this paper not onlyestablishs the system’s whole conception and executable program, but also completes thehardware structure, the control algorithm of MATLAB simulation and the flow of softwaredesign. The automatic feed drilling control system of oil rig with AC frequency conversion iswith S7-400as the core, double controller, double Profibus, double frequency converter, double motor to drill and related interlock protection and controlled by three-loop of hydraulic,speed and drill pressure ring, which makes the system redundancy bigger, safety better,reliability higher, the ability of dealing with abnormal accident stronger and the control effectmuch better.The field application confirmed that this control effect of algorithm is superior, someparameters of drill including drilling rate and drill pressure can be adjusted automaticallyaccording to stratum situation, drill can select auto-drilling with the constant drilling pressureor constant drill rate according to the scope of the drilling pressure, the control system canrealize the steady state accuracy of send drill within±0.5T with send drill more smooth andthe control algorithm also be general, which achieves the design purpose of this paper. |
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