Output-Boundary Regulation Using Event-Based Feedforward for Nonminimum-Phase Systems

This research addresses a disturbance-rejection problem for nonminimum-phase systems. Exact disturbance cancellation can be obtained by using inversion-based feedforward, but preview information of disturbances is required for nonminimum-phase systems. The output-boundary regulation (OBR) approach is proposed when sufficient preview information is not available. In particular, OBR rapidly transitions the output to a desired value so that the effects of disturbances are maintained within given boundaries. The main contributions of this research are to develop a rapid output transition technique using inversion-based feedforward and to quantify manageable types of disturbances for the proposed OBR using an event-based feedforward approach. Simulation results for linear and nonlinear nonminimum-phase system examples are presented to illustrate the proposed OBR approach.