| 80MN titanium-alloy forging hydraulic press is a large type numerical control isothermal forging hydraulic press manufactured newly by China, and it blazes a new trail in standard, structure and performance of forging hydraulic press in our country. Owing to special forging materiel and complicated forging technology, very high control accuracy is required to such a large type numerical control isothermal forging hydraulic press. Main contents and progresses in this paper are as follows:(1) The structure of 80MN titanium-alloy forging hydraulic press is analyzed thoroughly. According to internal mechanism of the system, with reasonable hypothesis and simplification, the dynamic models of hydraulic mechanism, slide and other devices are deduced respectively. By means of synthesis to all the dynamic models, a comparatively accurate affine nonlinear dynamic model of 80MN titanium-alloy forging hydraulic press is set up.(2) The conditions for the feedback linearization of nonlinear system are discussed. Aimed at the characteristics of the affine nonlinear dynamic model of 80MN titanium-alloy forging hydraulic press, a feedback linearization decoupling controller is designed. It solves output tracking control problem validly.(3) The basic structure of fuzzy controller is introduced. Fuzzifier, fuzzy rule base, fuzzy inference and defuzzifier of fuzzy controller are explored in detail.(4) To solve the problem about the stability of internal dynamics of the system in the input-output linearization method, according to the characteristics of the structure, the relationship of the physical variables and the experiment data of 80MN titanium-alloy forging hydraulic press, a supervision controller is designed with fuzzy control method and introduced into the input-output linearization controller of 80MN titanium-alloy forging hydraulic press. It can ensure the internal dynamics of the system are controlled within a limited range in the whole process of output tracking.(5) To resolve the conflict between the synchronization error and the distribution of the force on the slide in the four-corner leveling control of 80MN titanium-alloy forging hydraulic press, according to the characteristics of the structure, the relationship of the physical variables and the experiment data of 80MN titanium-alloy forging hydraulic press, a compensation controller is designed with fuzzy control method based on the feedback linearization decoupling control and the fuzzy supervision control. It can improve the synchronization accuracy of the system further.(6) Based on the application of the mixed control which is composed of the feedback linearization decoupling control, the fuzzy supervision control and the fuzzy compensation control, a control program of the velocity of the slide and the strain rate of forging parts, a four-corner leveling control program of the slide and a new bi-closed-loop control program are given to realize the control of the velocity of the slide and the strain rate of forging parts, the four-corner leveling control of the slide and the coordination control of the velocity and four-corner leveling of the slide.
|
PDF Full Text Request