Performance Analysis And Control Research Of The Linear Electromagnetic Loading System

The linear electromagnetic simulation loading test bench was developed by our research group has a good application value for the simulated loading of the mechanical equipment with linear motion, and the hysteresis nonlinear characteristic of the loading system seriously affects the loading accuracy.Therefore, it isof great significance to study the performance analysis,hysteresis modeling and hysteresis nonlinear compensation control of linear electromagnetic simulation loading system.In this paper, taking the linear electromagnetic simulation loading test bench as the research object, the kinematics, dynamics model and hysteresis system model of the loading system are established, and the hysteresis nonlinear compensation control method is designed, and the corresponding results of the above analysis are verified. Specific work is as follows:Firstly, the structure and working principle of the linear electromagnetic simulation loading test bench are described in detail. And the hysteresis characteristic of the magnetic brake is pointed out, which leads to the hysteresis nonlinearity of the loading system.Secondly, according to the mechanism diagram of the test bench, the expressions and curves of the kinematic parameters of the loading head, the eccentric crank disk and the connecting rod are obtained respectively. In addition, based on the kinematic analysis, the eccentric crank disk is used as the equivalent component of the equivalent dynamic model of the loading system, and its equivalent moment, equivalent moment of inertia and its derivative are obtained. Thus,the equivalent dynamic model of the loading system is established. At the same time, kinematics and dynamics were simulated by Adams software.Thirdly, the working principle of the magnetic powder brake is introduced in detail, and the mechanism model of the magnetic powder brake is established according to its working principle. The hysteresis characteristic and the cause are analyzed. At the same time, the hysteresis model of magnetic powder brake is established by using Duhem model, and the model parameters are identified by recursive least squares method, and the hysteresis model is established.Finally, the paper establishes the hysteresis inverse model of the loading system and studies the control scheme of the loading system at a certain time according to the freezing coefficient method. The inverse mode feed-forward compensation control and the PID closed-loop control method based on inverse model feed-forward compensationis used tosimulate the two control methods in Matlab/Simulink environment. The control method has some effect on the hysteresis compensation and the loading precision of the loading system.Among them, the effect of inverse model feed-forward compensation of PID closed-loop control is more obvious.