Research On Control Strategy Of Balanced Self-weight Structure For Heavy-duty Horizontal Servo Of Rolling Shear

With the rapid development of the national economy,the requirements for the quality of plate steel are getting higher and higher,so that the degree of automation of the metallurgical equipment required by steel production companies will also increase.Rolling shear is the core equipment of the steel plate finishing line,and the cutting accuracy of the plate is an important standard parameter of the plate quality.In order to improve the quality of the plate,the production company constantly make technical innovations and equipment upgrades for the rolling shear.The servo hydraulic cylinder is the core equipment of the full-hydraulic hobbing shear.Due to the large weight of the cylinder,its frequency response characteristics and lifespan are greatly affected,as well as the production efficiency of the matching hobbing shear.For this reason,it is necessary to carry out technical innovation on the servo cylinder to avoid a series of adverse effects caused by the cylinder's own weight.In this paper,starting from the actual engineering,in order to solve the problem of wear,leakage and insufficient output force of the seal ring caused by the weight of the horizontal servo cylinder,a new type of structure was designed to connect and support small cylinders at the end of a horizontally articulated servo cylinder,and a servo control system was designed.The following researches were performed: First,the structure was subjected to force analysis and its dynamic model was established.The movement principle of the structure was reflected in the form of a mathematical model,and the dynamic simulation was performed using Simulink.Secondly,a position-pressure double closed-loop PID control system based on position closed loop and pressure closed loop was designed.The pressure signal was converted into a position signal,and the position feedback signal acts on the system at the same time.By changing the displacement of the small cylinder by time,the cylinder of the servo cylinder was supported and the horizontal servo cylinder was operated without friction.The position-pressure double closed-loop control system wasstudied and analyzed,and the operation was deduced.The transfer function of the position-pressure double closed loop was obtained.The stability analysis was performed using the Lyapunov second method,and AMESim and MATLAB were used for the joint simulation.Finally,this paper designed the internal model PID controller,introduced it to the PID controller design,established the relationship between the filter parameters and the PID parameters,and used the internal model control to design the PID controller.Because the transfer function of pressure and position closed loop is very high,it is first reduced to a second-order time delay,and then it is simulated using Simulink and compared with PID.The simulation results show that the internal model PID tuning parameters are convenient and the control results are excellent.