High-precision pouring control using online model parameters identification in automatic pouring robot with cylindrical ladle

摘要

This paper gives an advanced control system in tilting-ladle-type automatic pouring robot in casting industry. In recent years, an automatic pouring robot has been exploited to improve the working environment of the pouring process and to produce stable casting products. Furthermore, the automated pouring process has been required that molten metal is quickly and precisely poured into the mold. However, the conventional control systems of the pouring robot need the preliminary experiments for tuning the control parameters. These experiments take an immense amount of time and effort. Moreover in case that the pouring conditions are changed from the conditions of the preliminary experiments, it is difficult to pour precisely the molten metal by the pouring robot with the conventional control systems. Therefore, we propose the pouring control system which control parameters are automatically tuned for pouring precisely in this study. In this proposed approach, the online model parameters identification and control parameters updating system are integrated with the pouring control system based 011 the mathematical model of the pouring process. These model parameters are identified automatically by minimizing the error of practical data and the simulation data from the model at every pouring motion, and then the control parameters according to the mathematical model of the pouring process are updated online to the controller. Therefore, even if the pouring conditions are changed, the molten metal is poured precisely by the proposed pouring control system. The effectiveness of the proposed pouring control system is verified by the experiments with the tilting-ladle-type automatic pouring robot.