Research On Hydraulic System Of High Speed CNC Punch Machine Based On Cloud Model

With the continuous progress of industrial development,the demand for processing equipment is more and more exuberant and higher.The application of high speed punch machine,as a high-grade processing equipment,is more and more widely used in the sheet metal industry.Now the CNC machines are wildly used in many indutries.As the core part of the CNC punch machine,the dynamic character of the special hydraulic system directly affects the product performance of the CNC punch machine.Its special CNC system is complex and sensitive to the working environment.It is easy to be influenced by nonlinear factors and external interference.Therefore,the research of high-performance numerical control hydraulic system has been the focus of the research field of CNC punching machine.This paper describes the development status of CNC punch machine,introduces the structure of CNC high speed punch machine and hydraulic system,and emphatically introduces the working principle of hydraulic system.The mathematical model of the hydraulic system is finally determined by modeling the valve controlled cylinder,servo valve,displacement sensor and proportional amplifier.Under the ideal state,the system is simulated and compared with PID controller,one dimension cloud model controller and one dimensional compound cloud model controller respectively.The simulation results show that the control effect of one dimensional composite cloud model is the best.However,considering the unavoidable nonlinear factors and external disturbances in the actual working environment,the hydraulic system often has the problems of hydraulic impact,reversing vibration and signal interference during high speed operation.The traditional PID control is insufficient in response to multiple interference factors,nonlinear systems and load changes.The development of intelligent control provides a new idea to solve the problem of nonlinear and uncertain system control.In this paper,taking the general hysteresis nonlinearity as an example,in the view of good control effect of the one-dimensional composite cloud model in the ideal state,the hysteresis nonlinearity is added to the model.The simulation results show that the one dimensional compound cloud model has obvious overshoot in the control system when the system has nonlinear problems.Therefore,combining the two dimensional cloud model with the PID control,a self-tuning control strategy of PID parameters based on the twodimensional cloud model is proposed.On the basis of PID control,the control parameters of the PID are adjusted in real time through the reasoning mapping of the two-dimensional cloud model,and the control of the system model is realized.The simulation results show that the PID cloud self-tuning controller has better control and the feasibility of the control strategy is verified.At last,summarized the research content of this paper,analyzed the problems in the control of hydraulic system and the further improvement is put forward,which provides some guiding significance and reference for the research of the hydraulic system of the CNC punch machine.