Industrial applications of locally weighted PLS to realize maintenance-free high-performance virtual sensing

Virtual sensing technology is crucial to realize high product quality and productivity in any industry, but model maintenance is the most critical issue because the estimation accuracy deteriorates due to changes in processes characteristics and operating conditions. In order to realize maintenance-free high-performance virtual sensing, locally weighted partial least squares (LW-PLS) was proposed and has been successfully applied to various industrial processes. In this article, the algorithm of LW-PLS is explained focusing on the effect of similarity measures on the estimation performance. In addition, several industrial applications of LW-PLS are presented.