Development of indirect method for clothing pressure measurement using three-dimensional imaging

A direct measurement method using an air-pack-type pressure sensor has been used widely to obtain clothing pressure, but this method still has many limitations. For instance, it gives only pointwise information and is inherently inconvenient and error-prone. Therefore, we suggest an indirect method for measuring the clothing pressure of various positions at once without touching the subject by using three-dimensional (3D) deformations of a reference shape (i.e., a circle grid) printed on clothing. The clothing pressure can be obtained with a simple analysis of tensile stress and the curvature data extracted from the 3D deformation of circle grids on the clothing surface. Specifically, the tensile stress of the fabric was obtained from a tensile tester and the direction of the principal stress and the radius of curvature in the principal direction were measured from 3D imaging data to obtain an accurate value. The clothing pressure from the indirect method was verified by comparing the results from direct pressure measurements using an air-pack-type pressure sensor. The indirect method was found to successfully estimate the clothing pressure.