Modeling And Simulation Of Mixed Anti-deflection Of A 6.5MN Closed-die Hydraulic Press Based On MATLAB

With the advancement of technology,precision requirement of stamping hydraulic press is becoming increasingly important.To study the anti-deflection of hydraulic press in working condition,the research can be concluded as a multi-dimensional,high friction,highly-nonlinear,accompanied by uncertain displacement and rotation control.In this study,6.5MN stamping hydraulic press was cited as a prototype of 650 MN stamping hydraulic press which have already been used in fieldwork.The simulation model of the press was established involving knowledge about mechanics,hydraulics measurement and control,etc.In reference of existing techniques and documents,absorbing research experience on anti-deflection home and abroad and not dwelling on the analysis of the single part,systematic anti-deflection model of stamping hydraulic press was constructed idealistically,ignoring the unimportant factors.(1)Based on current technical data and documents,overall structural parameters of 6.5 MN forging hydraulic press the,including the hydraulic cylinder position and its arrangement were obtained.Also on the basis of the original 6.5 MN hydraulic synchronous control system,sensors and hydraulic actuators were selected to redesign the hydraulic principle diagram of anti-deflection system.Mathematical modeling involving major components and the whole of anti-deflection system was established through analytical method.Dynamic behaviors of major components and the whole of anti-deflection system under simple working condition was simulated using MATLAB/Simulink in order to achieve a better optimization on the premises of meeting the demand of stabilization(2)To simplify the control model and to decrease the difficulty,a multi-cylinder synchronization model in which the large inertia moving beam was reduced to a disturbance was first considered.Two kinds of multi-cylinder coupling connection mode,namely,diagonal and master-slave structure were put forward.Again,the whole model of anti-deflection system including the moving beam was established on the basis of the above work to investigate the simulation of displacement and anti-deflection of the moving beam.(3)The research of anti-deflection of the moving beam moving beam can be divided into two main contents: the position control and deflection control.Given the simulation models the system and each part,the unilateral loading condition was employed to simulate by adding simple PID control strategy.Results showed that by adding the PID the displacement error and the angle of deflection can be improved,but cannot be eliminated.The variation trends of each parameter were roughly determined,thus the optimal parameters were also obtained.Results showed that under the setting condition(The load is in the positive X-axis),the displacement of the plunger cylinder finally reached 39.89 mm,the tracking error was within the scope of 1.03×10-4m,the X-axis angle of deflection was close to zero and the Y-axis angle of deflection stabilized around-4.19×10-4 rad.Considering the displacement control,the parameters of PID controller was set as 1.2,10 and 0,respectively.And the tracking error was stabilized within the scope of 10-6 m.Considering the anti-deflection control,the parameters of PID controller was set as 10,100 and 0.1,respectively.And the angle of deflection was stabilized within the scope of 10-5 rad.(4)A Load-displacement curve was adopted as the load model to simulate the actual load condition,which is close to the engineering practice.During the simulation process of two different load model changing with stroke,namely,the single linear load and piecewise load,was employed to investigate the influence of different load conditions on process regulation and accuracy.In order to further improve the control precision of the system,a PID controller was adopted as the core element of simulation.The results proved that the displacement and deflection of the moving beam must adopt independent PID controller,and simply through PID optimization can obviously improve the control precision of the terminal displacement.The simulation process of each cylinder is close to the engineering practice.Therefore,the results of the study are applicable to engineering practice.Finally,the implementation of the control system from the aspects of hardware and software are simply described.