Tuning of feedback type decoupling controller for two-dimensional thermal process based on VRFT method

Thermal distribution in manufacturing processes, which is observed in both steady and transient states, causes inferior quality. To suppress the thermal distribution, parameter tuning method appropriate to the real plant has been required. For the plant with strong thermal interaction, decoupling control would be effective from the view point of the tuning time reduction. However it is difficult to use the traditional feedforward type decoupler in industrial applications, because the decoupler has disadvantages, e.g. the system is not robust for disturbances, the decoupler is not proper in many case, and so on. To overcome the difficulties, we have proposed the temperature difference model (TDM) for thermal process and the decoupling controller based on the feedback structure. Focusing the construction of the decoupling system based on TDM, the decoupler can be obtained by virtual reference feedback tuning (VRFT) method, which is powerful offline tuning method of the controller. In this paper, a VRFT method of the new feedback type decoupler for MIMO system is proposed. The effectiveness of the VRFT for two-dimensional heat plate is evaluated by numerical examples.