Human shape recognition performance for 3D tactile display

The purpose of this study is to describe the relationship between the pin-matrix density of a tactile display and the recognition performance of displayed three-dimensional shapes. Three types of pin-matrix tactile display, that generate 3D shapes, were used for the experiment. The pitch of pins was 2 mm, 3 mm, 5 mm for each. We assumed that surfaces, edges and vertices were primitive 3D shape information, so tested shapes were classified into these three categories. We assumed two types of finger touching mode. One, fingertip-only, allowed full use of spatial shape information given to the fingertip. Another, tracing, allowed tracing of the object. Recognition time and the classified error rate were measured. We obtained results on the relationship between pin pitch and recognition performance data. Regression curves for pin pitch and recognition time were plotted and a significance test of recognition time vs pin pitch was done. Also the error rate of identification vs pin pitch was described.