A master–slave generalized predictive synchronization control for preheating process of multi-cavity hot runner system

Abstract

As a key component of injection molding, multi-cavity hot runner (MCHR) system faces the crucial problem of polymer melt filling imbalance among the cavities. The thermal imbalance in the system has been considered as the leading cause. Hence, the solution may rest with the synchronization of those heating processes in MCHR system. This paper proposes a ‘Master-Slave’ generalized predictive synchronization control (MS-GPSC) method with 'Mr. Slowest' strategy for preheating stage of MCHR system. The core of the proposed method is choosing the heating process with slowest dynamics as the ‘Master’ to track the setpoint, while the other heating processes are treated as ‘Slaves’ tracking the output of ‘Master’. This proposed method is shown to have the good ability of temperature synchronization. The corresponding analysis is conducted on parameters tuning and stability, simulations and experiments show the strategy is effective.