Position tracking control of a clamp-cylinder for energy-saving injection moulding machines with electric-hydrostatic drives

This paper deals with the issue of position tracking control of a clamp-cylinder for an injection moulding machine with electric-hydrostatic drives. In order to accommodate mismatches between the real plant and the model used for controller design, discrete-time sliding mode control is developed by combining a velocity feedforward loop. From tracking control experiments, it is shown that significant reduction in position tracking error is achieved through the use of a sliding mode control scheme. The effect of dry-cycle time on position tracking error is examined for the possibility of attaining a high-speed injection moulding machine.