Learning control of an electro-hydraulic injection molding machine with smoothed fill-to-pack transition

A learning control scheme with a bumpless transfer between the filling phase and packing phase is designed and tested on an experimental injection molding machine (IMM). Building upon the learning scheme tested in Havlicsek and Alleyne (1999), the current control system takes into account both of the two learning control phases and initiates a smooth transition between them. A high gain bumpless transfer scheme is described and tested successfully. The experimental results presented show much better performance for the transition between the two learning controllers. Under the current scheme, when the second (packing phase) controller takes over, the IMM system has a significantly smoother control signal and pressure transient than the scheme presented in Havlicsek and Alleyne, (1999). The current scheme partially resolves the problem of the fill-to-pack transition in IMM control