PERFORMANCE ASSESSMENT MEASURES FOR UNIVARIATE FEEDBACK-CONTROL

A normalized performance index, eta(b), is introduced to characterize the performance of feedback control schemes. eta(b) is attractive because it provides a measure of the proximity of control to minimum variance control, which is the optimal feedback control provided that the process can be described by a linear transfer function with additive disturbance. Both time domain and spectral interpretations of this performance index are discussed. A fast, simple, on-line method for estimating eta(b) is given, along with some of the statistical properties of the estimator. Simulation and industrial examples demonstrate the utility of eta(b).