Reserch On Position Servo System Of Swing Motor For The Loggin With Drilling

LWD (Logging While Drilling) is an important technology of petroleumengineering, and the low speed of data transmission is a challenge which restrictsthe development of LWD technology. LWD information mostly decoded and sendby pulse generator, in the pulse generator permanent magnet synchronous motor iscontrolled to move as a given frequency and amplitude to send data. this paperfocuses on the servo system which can output motor position accurately andquickly.For three-loop structure due to the problem that three-loop structure’s serieslinks is too many and the poor dynamic response of the position loop, this paperdesigns position-current structure to improve the dynamic performance of thesystem. it establish the mathematical model of permanent magnet synchronousmotors in this paper, designe regulator of the two systems based on it. Then itanalysises control performance synthetically, including dynamic performance andthe capabilities of resistancing load disturbance. Next, it analyzes the anti-loaddisturbance performance when uses a different position regulator.In the view of the problem that it is difficult for PID controller to followsinusoidal signal which changes rapidly without steady-state error, this paperembedded repetitive controller on the basis of the original controller and analyzethe performance of embedded repetition control systems in detail. Next repetitivecontroller is designed based on the principle of repetitive controller and themathematical model of two ring structures, and the impact of the controllerparameters for system performance is analyzed. The results showed that therepetitive control system designed can effectively reduce the error of the servosystem to follow a sinusoidal signal, and can effectively inhibit the system loaddisturbance.The SVPWM model of permanent magnet synchronous motor control system iscreated in MATLAB/Simulink. Then conduct the simulation analysis the controlperformance of the three control system, and the simulation results show thatrepetitive control system based on the two-loop structure can follow a givensinusoidal signal with smaller static error, faster dynamic response. Final, Simulatethe load disturbance swing motor suffered in the actual environment, and simulationresults show that repetitive controller improve the load disturbance capability ofdouble-loop control system.In the last, the hardware circuit of LWD swing motor’s digital position control system, including control circuits, auxiliary power supply circuit, the current andthe location of the sampling circuit, the main power circuit and driver circuit isdesigned and made. And the software for the servo system is designed, thenexperimented on the hardware circuit. Experimental results show that positiondynamic performance of repetitive control system based on the double-loopstructure is better, follow precision is higher and meet the requirements of controlperformance.