Merenje debljine gumiranog korda primenom laserske triangulacije, deo I - tehnologija

Abstract

U radu je prezentiran konceptualni okvir tehnologije merenja ekvivalnentne debljine gumiranog korda primenom optičke triangulacije. Detaljno je izložen analitički model laserskog proksimetra i razmatrani su osnovni problemi vezani za funkcionisanje i primenu laserske triangulacije u merenju distance objekata sa izrazito tekstuiranom površinom koja poseduje neuniformna optička svojstva. Predložena je nova metoda koja omogućava robusnu i visokopreciznu estimaciju efektivne debljine gumiranog korda. Ova metoda je bazirana na struktuiranju površi na tri sloja i statističkoj karaketerizaciji ovih slojeva. Pokazano je da tekstura gumiranog korda odgovara klasi Gausovih površi, na osnovu čega je moguće precizno i vrlo robusno izračunavanje ekvivalnetne debljine samo na osnovu estimiranih parametara normalne raspodele skeniranog uzorka površi. Laboratorijski eksperimenti su potvrdili praktičnu upotrebljivost ove metode i stvorile realne osnove za razvoj nove tehnologije mernih sistema koji će moći da zamene konvencionalna rešenja bazirna na senzorima sa prirodnim ili veštačkim švorima radioaktivnog zračenja.

Steel and textile cord coating is one of the key rubber processing technologies in tire making industry. Specifications are very demanding. In particular, thickness variation across the sheet profile and downstream is very difficult to fulfill. For in-process thickness measurement the most common are systems based on non-contact beta or gamma radiation sensors. Regardless of their wide use, non-contact radiation sensors possess serious drawbacks: they are measuring thickness in indirect way only, they are highly sensitive to variations of material properties, and probably the most critical one, they are potentially dangerous for both personnel and environment. Recent advances in optoelectronics have founded new alternative method for non-contact thickness measurement based on laser triangulation. Extremely delicate optical properties of fresh calendered rubber and severe environmental conditions create serious problems in implementation of this technology. This two-part paper presents a general conceptual framework for in-process laser-based thickness measurement, and proposes a new method for processing acquired sensory data based on statistical surface characterization. Proposed method is experimentally verified, and based on these results the new measuring systems are developed and implemented in industry.