ROBUST ESTIMATION OF NON-REDUNDANT MEASUREMENTS AND EQUIVALENT SETS OF OBSERVATIONS

LLANOS, CLAUDIA ELIZABETH; SÁNCHEZ, MABEL CRISTINA; MARONNA, RICARDO A.

INDUSTRIAL & ENGINEERING CHEMICAL RESEARCH

AMER CHEMICAL SOC

Año: 2019

0888-5885

Theequation-oriented estimation of measurements constitutes the initial stage ofmany procedures devoted to optimize a chemical plant. Nevertheless, theestimation of non-redundant measurements and observations related to equivalentsets of systematic errors remain unsolved problems, which deteriorate theknowledge of the actual process operation. In this work two statistical tests,which can take part of the estimation method and deal with those problems, areanalyzed. The Window Measurement Test is easily computed using an analyticexpression while the Robust Measurement Test uses robust statistics concepts tocalculate the measurement adjustment and its covariance matrix. Both tests takeadvantage of the spatial redundancy given by the process model and the temporalredundancy provided by a window of process observations. Performance resultsdemonstrate that the tests are able to detect atypical observations values forall kind of measurements, and highlight the improvements achieved with the useof robust statistics.