Adaptive GPC control of melt temperature in injection moulding

The melt temperature is a critical process variable affecting directly the final quality of the moulded parts. The control of this variable is difficult as the dynamics of the resin melting process are known to be nonlinear and varying in relation to the barrel heating power. In this paper, we present the development of an adaptive generalised predictive controller (GPC) which is suitable for the control of the melt temperature. Unlike previously reported controllers, this controller remains highly effective under a wide range of processing conditions which will excite the nonlinear modes of the process. Simulation examples are provided to highlight the effectiveness of the control system. (C) 1999 Elsevier Science Ltd. All rights reserved.