Run-to-Run Control Methods Based on the DHOBE Algorithm

Abstract

Many run-to-run (RtR) control methods have been developed in recentyears. Two particular set-valued RtR control schemes based on the Dasgupta-Huang OptimalBounded Ellipsoid (DHOBE) algorithm are introduced. Compared to other RtR control schemes, the methods in this paper only need to know the bound of the noises, and are easyto implement.<p>The DHOBE algorithm, for eachrecursion, returns an outer bounding ellipsoid of the estimated parameters. If the center of the ellipsoid each time istaken as the model coefficients, the explicit model update isimplemented which leads to a model-reference method. If we choose theworst-case point which maximizes the cost function in the set, then wecan apply the set-valued worst case approach. These two methods were compared with two other main RtRcontrol schemes: the Exponentially Weighted Moving Average (EWMA) methodand the Optimizing Adaptive Quality Controller (OAQC) method. Simulation results showed the superior performance of the RtRcontrollers based on the DHOBE algorithm. Furthermore this paper showedthat it is necessary to applynonlinear models to compensate for severe nonlinear processes.