Research On Nonlinear Control Method Of Hydraulic Forging Machine System

Forging hydraulic press machine is regarded as one of the developing directions offorging press machine because of its fast forging speed, high control accuracy,highautomation,wide technology range,saving energy and stuff.It is a product that couldreplace large type of forging hammer and nesotype and minitype common forgingwater press machine.In this paper,it concludes the current status and developing tendency of hydraulicforging press machine in domestic and on abroad. The work principle of hydraulicpress and its control system are studied.And the the model that oilways are couplingand the model that oilways are independent is built.And then, according to the model built ,two kinds of controller aredesigned.According to the model that oilways are indepdente, the cascade control isadopted. The outer loop are velocity loop;and the H∞Robust controller that controlsthe velocity and sychronism are designed with consideration of disturbance and theperformance . The inner loop are press loop.The controller adopts the backsteppingadaptive control algorithm,which make the load pree as the desired load press. Theadvantage of backstepping adpative arithmetic is that it need not linearize anddecouple. As the simulation proves, the control method has very good trace andsychronism performance and good adpatibility to the parametric variation model.According to the coupleing oilway model, the neural network inverse system isadopted to linearize and decouple the system.And then desigh the control inaccordance with the system.The simulation shows that the system that has beenlinearized and decoupled ,under the linear robust control algorithm ,also has goodperformance.