Application And Research On Damper Of Magneto-rheological Fluid In Electro-hydraulic Servo Servo System Of Hydraulic Dynamo

The inlet valves of the hydraulic dynamo with sequence-valve control system usually exist surge in our country, which indicate the dynamo is not stabilization and badly play down production's precision. One of the main assignment in the hydraulic control field is to improve the hydraulic system's low speed characteristic. Because of many factors' influence such as dry friction, hydraulic system often brings on spasmodic motion in low speed phase. Customarily we call it stick-slip motion. Stick-slip motion means the system is not stabilization. Stick-slip motion will badly reduce the stabilization of the dynamo' rotate speed. It also influnces the frequency of power supply of the dynamo.We analyze the principle of stick-slip motion deeply. From foregoing analysis a result was made that dry friction is the main factor in influencing low speed capability of electro-hydraulic servo system. Dry friction must be compensated for improving the low speed performance. Then a nonlinear model with friction is set up and control methods is discussed. Stick-slip motion is surge of limit cycle. It is a intrinsic phenomenon in unstable nonlinear system. It is a problem of the object's intrinsical nonlinear. For eliminating the stick-slip motion, we must start from the nonlinear field. According to the cause of stick-slip motion, a method of compensating the negative stiffness is proposed.Advanced research product both here and abroad in this field is absorbed. The virtue and shortage of traditional compensation method in dry friction is summarized. Then a new damper of magneto-rheological fluid is designed. The new damper is very suitable for control. But thinking of its nonlinear model and disturbance in the dry friction model, the paper adopt intelligent control, by the feedback of speed, a RBF neural network is trained to control input current of damper of magneto-rheological. Ultimately the damper can compensate the negative stiffness of dry friction.In allusion to the system of being compensated in damp, integral control is introduced. It comes true that the system follows up low speed through linear state feedback. The system's low speed dynamic performance is improved. The results of simulation indicate that the closed loop system does not exist dynamic bifurcation and overshooting does not exist too. The closed loop system has good dynamic quality. The control assignment is achieved entirely.