The application of fuzzy theory for the control of weld line positions in injection-molded part.

This research proposes the fuzzy theory for the control of weld lines in plastic injection molding. The weld line occurs as a result of geometrical changes in molded parts in the injection molding process. The weld line is one of the defects present in plastic injection-molded parts; the line affects the quality of parts as well as the strength of the products. In the present study, fuzzy theory was applied in the design of injection molding. First, expert experiences were transformed into IF approximately THEN approximately rules to establish the knowledge base for developing fuzzy inference rules. The rules were then used to adjust the molding parameters, which in turn were applied to control the weld line position in the injection molding process. The results indicate that fuzzy theory exhibited favorable applicability in the control of the weld line as well as decreased the simulation time, thereby accelerating the design process of injection molding.

A new mechanism design of electro-magnetic actuator for a micro-positioner.

This paper proposes a new type of non-conventional electro-magnetic actuator (EMA) for micro-positioning. It is a repulsive magnetic system consisting of a motion pad and two active coils. The motion of the pad is caused by the repelling force between the coils and the permanent magnets on the pad. First, the dynamic model is derived and analyzed. Next, an adaptive sliding mode controller is developed to deal with the unknown parameters with the objective of precision positioning. The experimental results demonstrate satisfactory performances including regulation accuracy and control stiffness for the system.