Measurement of the perimeter of curved elements by laser sensor triangulations

In this work a new system for the cross-sectional perimeter measurement of curved elements has been studied and built. An example is shown of an application to the measurement, in the production line, of the pipe perimeter employed by the automotive industry to realize the exhaust head. Digital simulation models enabled an evaluation of the uncertainty of measurement which arise depending on the algorithms of the calculus adopted and the experimental configuration of the sensors. A comparative analysis of the results enable an optimal choice of the mathematical model to analize the data and to establish experimental configuration of the used sensors. Subsequently, the measurement chain was set up and a software for the analysis of the experimental data developed. Some measurements were carried to define the principal non desired input and the causes of uncertainty. The analysis with patterns of known geometry enabled a characterization of the complete system and a comparison of the values of the uncertainties with those obtained from the computer simulations.