EMP: Extended kalman filter based self-adaptive mold protection method on a toggle mechanism

Abstract

Nowadays, the plastic injection molding industry is ever-growing, crucial, and its plastic products can be seen everywhere. However, the mold damage problem still frustrates operators because of its high maintenance price and time-consuming maintenance process. This damage is commonly caused by foreign bodies in mold area, and the conventional mold protection method is insufficient for high-performance injection molding machines because of the uncertainty from many setting parameters. To improve detection precision of mold protection driven by a toggle mechanism (TM), this paper puts forward EMP, i.e., an extended Kalman filter (EKF) based self-adaptive mold protection method, wherein the EKF is used in current curve optimization, and the self-adaptive method (SAM) is proposed to gain an safety range of current curve. The EMP was verified in a 140-ton electric injection molding machine. Compared with a general method, the proposed method decreases the detected distance of mold protection by 22% under different thickness foreign bodies.