Parameter Identification And Simulation For Hydraulic System Of Hydraulic Die Forging Hammer

25KJ Hydraulic die forging hammer is a novel hydraulic hammers developed by Taiyuan University of Science and Technology. In order to solve the problems of shock, hydraulic impact, noises and movement disorders of hydraulic systems, to enhance the working stability of system and optimize the working performance the dynamic performance of hydraulic system must be analyzed. Digital simulation is one of effective way to analyze the dynamic performance of hydraulic systems. However, how to determine the model parameters is a problem in the process of modeling, such as valve port flow coefficient, the transient hydrodynamic force coefficient, viscous damping and frictional resistance performance parameters, which are difficult to determine by theory methods. The traditional parameter determination is the values of parameters were selected according to the manual, documentation or experience. So it's not accurate. Moreover, with the changes of equipment working conditions the value of parameters will change too. Thus parameter determination affects the validity of dynamic performance analysis of hydraulic systems directly.To solve this problem, this paper raised parameter identification methods to determine the value of model parameters which were difficult to be determined by theory methods. The theories of grey-box modeling, parameter identification and dynamic performance were combined by the way of experiment. The value of model parameters could be identified by experiment data. Then, model simulation was done and the optimal results would be acquired. The main work and contribution of this paper are as follows:1. The theory and methods of parameter identification were researched.2. The working principles of hydraulic components were analyzed. The mathematical models of hydraulic components were built according to the theory of grey-box modeling. Then the simulation models library was built based on MATLAB/simulink.3. On the basis of the parameters which would be identified experimental programs were designed. And then the identification results of all parameters were acquired.4. The simulation for blow and return process after blow actions of 25KJ hydraulic die forging hammer was done, and simulation results were analyzed.This paper compared the simulation data and test data, and the results of simulation were in accordance with the test. The impacts of system identification for dynamic performance of hydraulic system given, and optical plan to achieve maximum blow power and adjustment methods for hydraulic system of 25KJ hydraulic die forging hammer were put forward.Parameter identification was used in the modeling and simulation of hydraulic system firstly. The results shows that the methods used in this paper were correct and feasible. This method solved the problems encountered during the modeling and simulation of hydraulic system. The study of this paper provides a theoretical and experiment basis for hydraulic system modeling, simulation and analysis of dynamic characteristics. So it has a great value and significance in application.