Multi-frequency disturbance compensation in a plastic injection molding machine

In this paper we present a strategy developed to compensate for multiple sinusoidal disturbances affecting the pressure output of an industrial revamped plastic injection molding machine. The method is based on the suitable implementation of an adaptive feed-forward control technique and has the characteristic that it can be added to the already existing standard control structures such as the normal feedback structure or the cascade one without modifying any part of them. Experimental results show that the technique allows the significant reduction of multiple sinusoidal disturbances affecting the same part of the plant.