Dynamics Modeling And Control System Design Of Hydraulic Drawing Machine

With growing popularity of natural gas vehicles, the productivity and quality of vehicles cylinders for compressed natural gas(CNG) need increasing. This paper focuses on the in-depth research on the control system of the hydraulic drawing machine, which is the key equipment of the punching-drawing production line, aimed to produce CNG cylinders. Considering the process requirements of the hydraulic drawing machine, with the characteristics of high pressure, large flow, high inertia, high precision,.the control system is designed, on the basis of analyzing the hydraulic drawing machine, especially the drawing process. The main work done is as follows:First, the research situation of the hydraulic control system of modern hydraulic machine at home and abroad, the application of the automatic control technology in the electro-hydraulic proportional control systems, are summarized in the paper by referring a large number of relevant literatures. The key factors, affecting the product efficiency and quality, are the stability and accuracy of the slide moving downwards, by analyzing the composition and working principle of the hydraulic drawing machine. The dynamical model of the slide moving downwards is established, on the basic of theory analysis.Secondly, considering that the hydraulic drawing machine is a large inertia, time-varying, nonlinear system, a Fuzzy-PID controller is designed, on the basis of analyzing the characteristics of PID control and Fuzzy control. The parameter self-tuning Fuzzy-PID controller makes the output tracking for the given curve, which is designed according to the field test data. These work conduct a feasibility analysis of a theoretical level for the subsequent control system design.Finally, on the basis of the analysis of the process and control requirement in the hydraulic drawing machine, a distributed-fieldbus control system is designed, taking consider of the overall solution of the punching-drawing production line. The control system mainly contains the hardware design of the master-slave stations, the configuration of the network, and the software of subordinate computer and principal computer. The result of analyzing the operating data demonstrates that the control system meets the requirements of the hydraulic drawing machine.