RPLS based adaptive statistical quality monitoring of rubber mixing process

An adaptive recursive partial least squares(RPLS ) monitoring scheme is proposed to improve the time-variant tracking power of the statistical quality monitoring (SQM) systems.When new samples are obtained, this new method updates the monitoring model and the Q statistic control limit (Q_α) on the basis of the improved RPLS algorithms.Thus it could overcome the shortage of the traditional fixed SQM successfully.The theoretical findings were fully supported by the application performed on the rubber mixing process in a large-scale tire plant in east China.It was shown that the compounds quality is improved remarkably and the false alarm frequency was reduced significantly.