Dynamic Characteristics Analysis Of Feed System Of VMC850 Vertical Machining Center Based On Co-Electro-Mechanical Simulation

The feed drive system of machining centers must have high speed and high precision requirements in today's high-speed machining.Therefore,the dynamic characteristics of the feed drive system play a key role in the machining center's processing speed,motion stability,and precision of the processed product.Therefore,it is necessary to analyze and study the dynamic characteristics of the feed-driven structure thoroughly.This project takes the VMC850 vertical machining center as the object of this study,and performs rigid-flexible coupling modeling and electromechanical integration to achieve simulation analysis of its dynamic characteristics.First,a multi-rigid body model of VMC850 was created by using SolidWorks and ADAMS together,and dynamic simulation was performed.The displacement and velocity curves were analyzed to prove the correctness of multi-rigid body modeling.Considering that the elastic deformation of the lead screw will fluctuate the feed rate of the machining center and affect the machining accuracy,a modal neutral file(MNF file)of the lead screw was created using ANSYS,and the rigid body lead screw was replaced with ADAMS.It is a flexible body.Then,the rigid-flexible coupling model is simulated and analyzed,and compared with the original multi rigid body model.The velocity curve of the rigid-flexible coupling model obtained by simulation fluctuates up and down in the vicinity of the velocity value of 0.5m/s.This fluctuation is caused by the elastic deformation of the lead screw,which indicates that the simulation analysis using the rigid-flexible coupling model is closer to the actual working conditions.Moreover,the influence of non-linear factors(moving joint surface,friction force,bearing starting friction,screw pre-tightening force)on the feed motion is considered,and the corresponding parameters are added to the simulation system to make the simulation model closer to reality.Then use MATLAB to create a control system block diagram,use PID control to adjust the parameters of the system,and combine the established rigid-flexible coupling model to create the required electromechanical joint simulation platform.Then adjust the corresponding control parameters according to the system response,and apply the response time evaluation index to analyze and evaluate the completed control system.The evaluation indexes of the X-axis,Y-axis,and Z-axis have decreased from 1.164,1.144,1.213 to 1.069,1.058,1.074,thus ensuring that the established control system responds quickly without overshoot.Finally,the established and adjusted electromechanical joint simulation platform is used for simulation.Two linear speed control methods and S-type speed control methods are discussed separately,which provides a theoretical basis for the machining center to choose a better speed control strategy.Then,the cam is used as the object of the simulation processing,and the position control instruction is input into the platform,so that the platform completes the simulation processing,and the obtained simulation trajectory is compared with the theoretical trajectory,and the defects and deficiencies in the simulation processing are expressed through analysis.And analyze the problem,and propose improvement methods.Changes in the dynamic parameters such as the displacement,velocity,acceleration and load of each component during the simulation can be analyzed by the ADAMS post-processing module,which provides a direction and theoretical basis for further improving the machining center.