Injection molding controller with controlled variable learning

Abstract From the Canadian patent

A controller for an injection molding machine controls the injection ram by means of profiles having segments with programmable setpoints. The injection molding machine is initially controlled during each segment in an open-loop manner. Closed-loop control is then adopted. The difference between the open-loop and the closed-loop output to the injection molding machines valves is used to change the setpoints with each cycle to improve the open-loop accuracy over time. The learning rate of change of the open-loop setpoints decreases after the initial correction. During the open loop control the closed loop control is, deactivated to prevent it from being affected by the previous open loop …