| The feed servo system is an important part of the CNC machine tool.As a precise position tracking and positioning system in the CNC system,its motion accuracy and positioning accuracy directly affect the final machining accuracy and machining quality.The linear motor feed servo system has a high Positioning accuracy and high-speed feed can be widely used in various high-speed and high-precision feed applications.Since the linear motor feed system cancels the intermediate transmission link,external disturbances such as thrust harmonics and cutting force directly act on the motor mover,which is more sensitive to external disturbances,and nonlinear factors such as thrust fluctuation of the linear motor directly affect its motion accuracy.The linear motor feed system is a typical complex electromechanical system.The output feed displacement,velocity and acceleration not only affect the dynamic characteristics of the mechanical system,but also the dynamic characteristics of the servo system.The change of the servo output force characteristics acts on the machine.The link will affect the dynamic characteristics of the mechanical system.In this paper,the linear motor feed system is studied,and its electromechanical coupling model establishment,characteristic simulation analysis and experiment are studied.The following results are obtained:(1)Based on the analysis of the structure and working principle of permanent magnet synchronous linear motor,the mathematical model of rigid-mechanical coupling of linear motor feed servo feed system was established by using Lagrangian Maxwell equation and energy conservation;(2)Using ADAMS to establish the rigid body model of the linear structure of the linear motor feed servo system,then generate the modal neutral file of the key components by finite element analysis ANSYS,import the modal neutral file into the rigid body model and replaced some corresponding rigid body parts,and Considering the nonlinear factors such as the elastic deformation of key components and the parameters of the table joint surface,a rigid-flexible coupling model of the mechanical structure of the linear motor feed system was established.(3)Based on the analysis of the principle of linear motor control,the control simulation model was established by MATLAB/Simulink toolbox,and the nonlinear adaptive genetic algorithm was used to optimize the three-loop PID control parameters.(4)Using the ADAMS/Controls module and MATLAB/Simulink to construct the rigid-flexible-mechanical coupling simulation model of the linear motor feed system,and simulated the analysis of the control parameters affecting the motion accuracy of the linear motor feed servo system;The linear adaptive genetic algorithm optimizes the control parameters of the rigid-flexible-electromechanical coupling simulation model,and compared and analyzed the three conditions(unoptimized,optimized control parameters of the motor control system,optimized control parameters of the rigid-flexible electromechanical coupling model)Leap response and sinusoidal response,it was found that the nonlinear adaptive genetic algorithm was used to optimize the control parameters of the rigid-flexible electromechanical coupling model.The system control effect was better,and the system has shorter settling time and the lowest overshoot,and the sinusoidal signal response.The peak value of the curve was not over-adjusted and the response speed was also faster.(5)The effects of different table loads on the dynamic displacement response of the linear motor feed system and the pitch and torsional vibrations of the table under different feed rates were experimentally studied.The simulation results of the electromechanical coupling model of the linear motor feed servo system were studied.Model validity was verified.The rigid-flex electromechanical coupling model of the linear motor feed system established in this paper is to study the electromechanical coupling mechanism and provide a theoretical basis for high-speed and high-precision feed motion applications. |
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