中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 18 No. 4 August 2008 |
（School of Materials Science and Engineering, State Key Laboratory of Solidification Processing,
Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:Counter gravity casting equipments(CGCE) were widely used to produce large thin-walled A357 aluminum alloy components. To improve the pressure control precision of CGCE to get high quality castings, a pressure control system based on fuzzy-PID hybrid control technology and the digital assembled valve was developed. The actual pressure tracking experiment results show that the special system by applying PID controller and fuzzy controller to varied phases, is not only able to inherit the small error and good static stability of classical PID control, but also has fuzzy control’s advantage of fully adapting itself to the object. The pressure control error is less than 0.3 kPa. By using this pressure control system, large complex thin-walled A357 aluminum alloy castings with high quality was successfully produced.
Key words: counter gravity casting; pressure control system; hybrid fuzzy-PID control; large thin-walled components
