Experiment Research On Position Synchronous Control System Of Double Sides Hydraulic Cylinder On Internal High-pressure Forming Equipment

Internal high pressure forming technology make use of tube as the raw material mainly,thrust the high pressure liquid medium into the tube internally,at the same time,supplementing liquid to the both side of the axial so as to tube cling the wall of mould,then,it can produce the wanted component.Because Internal high pressure forming technology saves raw materials,the weight of product is light and has a low cost,it is been used in more and more modern industry.Both side of the hydraulic cylinder position synchronous control of the internal high pressure forming equipment is one of the core technology,synchronous control precision directly affects the production efficiency.The paper conducts a study about this problem.The main research contents are as follows:First of all,according to the related literature,analyzed the basic principle and characteristics of internal high pressure forming,hollow structure and different pipe produced by this technology widely used in automotive,aerospace,marine and other fields.The research status quo of internal high pressure forming was analyzed,especially the research situation on both sides of the cylinder position synchronization control,finding out the lack of research in the area,then,put forward the main research contents in this paper.Secondly,the paper expounds the electro-hydraulic proportional control system,this is the kernel of both sides of hydraulic cylinder position synchronization control system of internal high pressure forming in this paper.Analyzed the hydraulic power mechanism,mathematical modeling for the single cylinder electro-hydraulic proportional control system,calculated parameters based on the experimental platform built.Established the"equal + principal and subordinate” control strategy,using PID control algorithm for the system are simulated,according to the characteristics of a given signal in the process of internal high pressure forming,the different slope changes the slope of the given signal simulation,find the limitations of PID control algorithm.Thirdly,PID control have much boundedness,for lack of interference suppression,slow response,robustness is not strong,tis paper research the whole integral sliding mode control algorithm to solve this problem,and the equation of state of the system,inaccordance with the whole integral sliding mode surface and the whole integral controller was designed,and its simulation was carried out.Seen from the simulation results,compared with PID control,synovial control algorithm can suppress the disturbance,better improve the robustness of the system.Finally,set up the PLC + industrial control both sides of cylinder position synchronization control experiment platform,using data acquisition card to displacement signal acquisition and the control signal output,the OPC technology make the real-time interaction between PLC and PC data,then gives the design of the upper machine,and write the application of sliding mode control algorithm.Then,has made the PID and sliding mode control algorithm of correlation test,test shows that two algorithms can satisfy the production requirements,but sliding mode control algorithm can better disturbance rejection,changes in load on its impact is not big,also can be applied to the production requirement of high places.