Fuzzy control of the ram velocity in energysaving servo injection molding machines

Since the injection velocity controller for the energy-saving servo drive system is essential, new type energy-saving servo system is becoming one of the hot development directions of injection molding machines. However the nonlinearity and irregular changes of load in the actual injection molding process makes injection speed control complicated. In this paper, an energy-saving servo injection control system using fuzzy control theory based on the re-establishment mathematical model of servo motor-driving fixed pump is presented, including the inputs/outputs of the system and their membership functions and the fuzzy control rule bank. The simulation results according to the parameters of Haitian plastics machinery indicated that the fuzzy controller can effectively reduce injection velocity tracking error. Additionally the system is good-robust compared with the traditional PID controller.