Design And Research On The Driving And Control System Of Heavy-duty Moving Workbench

Large forging hydraulic press is the key equipment in producing important forgings in the field of aviation, aerospace, shipbuilding, petroleum, chemical and heavy weapons. Forging hydraulic press need to replace different molds when forge forgings which have different sizes and shapes. Currently, the world’s leading manufacturer of forging presses use moving workbench to replace the molds. However, outsize forging presses have huge mass molds and moving workbench. Due to the large inertia, the startup process of moving workbench requires a large thrust and there will have a great impact and vibration in buffering process. Meanwhile, in order to ensure the accuracy of the forgings and prevent molds from taking excessive offset load force, forging machine also made high demands of docked position accuracy to moving workbench.As to these problems, this thesis chose a moving workbench of 8000t outsize forging hydraulic press as research object, compared the advantages and disadvantages of a variety of startup, buffer and position control method, selected the throttle speed cylinder driving system as the startup and buffer driving system, exert its advantages of high output force, smooth, and good controllability, meanwhile, impact and vibration in buffer process were reduced by the way of "pre-acceleration". Choose a hydraulic motor to accurately control the position of the moving workbench by using fuzzy PID control algorithm.The main contents are as follows:In chapter 1, the study background of this thesis was proposed, the work overview of the research object was introduced and specific design goals was proposed. Next, the current research status of startup system, buffer system and position control system are introduced. Finally, the significance and planed the specific content of the research was came up.In chapter 2, the advantages and disadvantages of a variety of startup, buffer and position control method were compared, the overall plan for the station I and station Ⅱ of startup, buffering and position control system were designed by combined with the actual situation of the forging press, overall plan specific and detailed and given the trajectory planning curve of each scenario were also made.In chapter 3, the key parameters of moving workbench were determined, hydraulic system was designed and hydraulic schematics was given, key hydraulic components were calculated and selection according to the need and adequately explain the choose reasons.In chapter 4, the mathematical model for proportional throttle, startup system, buffering system and position control system and simplified its model were modeled and the effect of the key parameter in the element and system were analyzed, it’s bedding for simulation and experimental validation later.In chapter 5, the AMESim model was modeled for proportional throttle, startup system, buffering system and position control system by using control program and trajectory planning curve and simulate for it, the simulation data with the data which were tested in the field was compared and the correctness of simulation model and the feasibility of the overall control plans were verified. Also, the differences between the two and analyzed its reasons were pointed out. Control algorithms were studied in the hydraulic motor position control system. Respectively established classical PID controller and fuzzy PID controller and co-simulated the control effects between the two by AMESim and MATLAB/Simulink, fuzzy PID controller can adjust the position for different mass and different initial position deviation moving workbench, and compared to PID controller, it has fast dynamic response and small overshoot torque.In chapter 6, the major work of the study was summarized. The conclusions, innovations and shortcomings of the study were elaborated. And future study and inadequate improving were also prospected.