A FUZZY RULE-BASED ITERATIVE LEARNING CONTROL METHOD WITH APPLICATION TO HYDROFORMING PROCESSES

Abstract

A pressure tracking control of hydroforming processes which is used for precision forming of sheet metals is considered in this paper. In this process, forming pressure of the process needs to be strictly controlled to ensure the high quality of the forming products. However, satisfactory control performance is often difficult to achieve using conventional control methods due to the complexities and the uncertainties of the process. To overcome the problems, a fuzzy rule-based learning control scheme is proposed. In the proposed scheme, a fuzzy rule base constructed from expert knowledge is adopted to generate an appropriate control input which will provide satisfactory pressure tracking performance of the hydroforming process. A series of experiments was performed to show the effectiveness of the proposed control scheme and to investigate the design parameters of the proposed algorithm. The experimental results show that the proposed fuzzy rule-based learning controller can guarantee good tracking performance and, thus, high quality of the products even when only a vague, imprecise and fragmentary knowledge of the process is available.