Design And Realization Of The Analog Loading System For The Fluctuating Load

This dissertation is mainly focused on the study of the design and realization of the analog loading system for the fluctuating load theoretifically and experimently, which fulfilled the design of measure and control system and finally realized this system. The main contents of the study are as follows:Based on the working principle of magnetic particle break theoretically, the mathematic model of the magnetic particle break deduced and established, and the effects of the break parameter are investigated. Then, based on the engineering practice, a kinematics model is developed for the mechanism of beam pumping unit by using the observed dynamometer cards and the structural parameter. The fluctuating torque of the output shaft of gear reducer generated from the suspension point load is computed for the measure and control system to analog load in the experimental laboratory.The mechanical system of the analog loading system is developed, and then, on the basis of the principal of PC,RS232/RS485 transmission net and the testing instruments, an inspecting and controlling system is constructed for the testing platform of simulation analog loading. By applying the muitithreads and multimedia timers and others technique of delphi7.0 in Windows environment, the software of the analog loading system is developed.Applying these systems, and combining the theoritical study and experimental research, repetitive loading with the fluctuating torque of the output shaft of gear reducer from the beam-pumping unit is realized. By comparing and analyzing measurement results and theoritical loades, the experimental approach which maximally reduce fluctuating loading error is obtained, i.e.: Calibrating loading devices by fluctuating load, fitting the loading measurement data by adopting the cubic polynomial interpolating function of the least squares theory, and obtaining the loading device equation of magnetizing current and loading torque which ensure the loading current series of the fluctuation loading.