Online optimization method of EWMA controller based on performance assessment
To solve the manufacturing characteristic of multi-type,small-batch and the quality reduction of controller caused by aging equipments in semiconductor manufacturing industries,an online optimization method based on performnance assessment was proposed for the most common used Exponentially Weighted Moving Average (EWMA) controller.In the process of performance evaluation,a new index was proposed by taking the mean square error defined in the time series analysis as the evaluation benchmark.The performance of EWMA controller was evaluated to obtain the current optimal parameters of controller and to auto-tuning.Meanwhile,online optimization was realized by combining with the moving window technology,which could make the control system maintain the optimum condition all the time.In addition,simulation of chemical mechanical polishing process was carried out to verify the feasibility and effectiveness of proposed method.
exponentially weighted moving average controlleronline optimizationperformance assessmentauto-tuning
NETL
NSTL
万方数据
维普
