Summary: | 碩士 === 國立臺北科技大學 === 車輛工程系所 === 93 === Traditional injection molding machine (TIMM) generally employs an open-loop control strategy for performing injection molding of plastic products.However, such control strategy cannot satisfy for injection molding requirement in complicated geometric shape with large size or hollow plastic products.Therefore, this work developed a closed-loop control strategy to control the TIMM during the filling and holding phases of injection molding;then the high-pressure gas of the gas assisted injection molding system was applied in holding phase of the post-filling process for achieving injection molding of plastic products.
The TIMM incorporated the gas-assisted injection molding system that was called gas-assisted injection molding control system (GAIMCS).The GAIMCS is clearly a nonlinear with uncertain system; hence, designing a model-based controller to control it is difficult because its mathematical model is hard to establish accurately.This work proposes model-free intelligent control strategies: (1) traditional fuzzy controller (TFC), (2) grey prediction fuzzy controller (GPFC), and (3) new modifying self-organizing fuzzy controller (NMSOFC),to control the GAIMCS for evaluating control performance of the system. The GPFC and NMSOFC have better control performance in quickening the rise time and reducing the steady-state error than does TFC,as verified by experimental results.
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