Multisensor Optical-Electronic Device for Calculation of Surface Parameters of the 3D Curvelinear Object

Abstract

The research covers the operation principles and structure functional organization of specialized optical-electronic device for calculation of a volumetric object. The purpose of the device is to build the 3D plane, which with the given degree of precision approximates the surface of the top and nape sections of a human head intended for implication in the production of customized headwear and elements of protectiveclothing or for other similar tasks related to the analysis of the 3D objectshape. The proposed device provides the ability to build the 3D model of an object under study by acquiring and analyzing the series of images of its surface continuously acquired from three or four optical-electronic sensors throughout the measurement process. The number of the optical-electronic sensors depends on the configuration of the optical-electronic device. Optical-electronic sensors organized in a given order relative to each other constitute a unified system, which in its turn is to be placed in the prescribed range of positions in relation to the head. In order to simplify the procedure and enhance the accuracy of calculation of special coordinates for a set of points of the object surface and reduce the computational complexity of the developed algorithms we use the tight-fitting contact hat consisting of a set of special contrast markers., which is to be put on the head. The following beneficial features of the proposed method and the optical-electronic device have the following beneficial features: (i) no strict requirements to interrelated positioning of the analyzed object and the system of the optical-electronic sensors; (ii) possibility to use commercially available web cameras as optical-electronic sensors; and (iii) no structurally complex and moving mechanical elements, which allow its mass use with no reduction in the accuracy of calculated point coordinates on the surface of an object required for practical tasks. The experiments we conducted showed that depending on the interrelated position of the device and the analyzed object our optical-electronic device gives the calculation error of the 3D coordinates of about ±2 to ±7 mm, which is sufficient for practical tasks.

Portable Scanner of a 3D Surface of a Curvilinear Object

“…The second mode is preferable for production of protective headgear and headwear. The calculation principle of 3D coordinates is covered in our earlier publication [1]. Now we present the principles of calibration which precision highly influences the operation of the scanner.…”