Performance Enhancement of Predictive Functional Control Using Disturbance Observer and Zero Phase Error Tracking Controller

This paper investigates a method to enhance the performance of the predictive functional control (PFC) using the disturbance observer (DOB). A control method that combines the PFC and DOB has been developed and shown to be effective in the past few years. However, there remains room for performance improvement by using a feedforward controller. Here, an approach to improving the tracking performance of the DOB-based PFC is presented by applying feedforward compensation using a zero phase error tracking controller (ZPETC). We provide the detailed background for this approach, and present properties of PFC controllers concerned with the transfer function representation. To verify the proposed method, we compare it experimentally to DOB-based and standard PFCs. We show that the tracking performance of the proposed method is much better than the other two control methods.