| Forging hydraulic press is considered as one of the developing directions offorging press because of its fast forging speed,high control accuracy,highautomatization,wide technology range,saving energy and material. It is a productreplacing large type forge hammer and mesotype and minitype common forging waterpressFirstly,in the thesis,the current status and development tendency of forge pressin domestic and abroad are investigated. The work principle of hydraulic press and itscontrol system are studied and developed. Secondly,the paper gives PID controlcomputer algorithm,on this base,integral division PID control,PID control withadvanced differentiation,PID control with uncompleted differentiation and PIDcontrol with dead band algorithm are introduced. The principle of Fuzzy control,thebasic structure of Fuzzy controller and the basic design methods are presented.Aimed at improving the controlled resolution and the reliability, combined withelectrical and hydraulic technology, fuzzy control strategy and PID method are herebyused to realize a high resolution control system for an forging hydraulic press. Thecore technology takes IPC and PLC to realize the constant speed control and the 5Hydraulic-cylinder synchronization control. The parameters of the hydraulic press aretested, and the relative data and test curves are given in the paper. The field controleffect has been appraised. The experiment indicates that the speed error is controlledwithin the limit of 5%, and the dynamic response is good. The synchronization errorcan be controlled in the scope of 30μm/m. This control system has been successfullyused in the 80MN isothermal hydraulic press manufactured by P. R. China, and hasachieved satisfactory economic and social benefit. |
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