Three Dimensional Position Detection Using a Two Dimensional PSD and a Marker Composed of Two Light Sources

Abstract

In recent years, the three-dimensional (3D) measurement is used in various fields. However, the conventional 3D measurement method has various problems such as complicated pre-set, slow processing and high price. In this study, in order to achieve the 3D measurement with simple preset, high speed processing and low price, we propose the 3D measurement method based on the new principle. It is the 3D position detection using a two-dimensional (2D) Position Sensitive Device (PSD) and a marker composed of two light sources. The major characteristics of the proposed method are as follows: Simple preset High speed detection Low price Not influenced by the reflectance of the object We can convert from the 2D coordinate of the spot lights on the photosensitive area to the 3D coordinate of the marker by the proposed conversion formula. Moreover, the 2D PSD can receive the lights at the same time by using the light sources which is modulated frequency. We performed experiments of four types to verify the measurement accuracy. We compared the experimental result of accuracy standard with the experimental results in the case of setting wide interval of light sources, using the high luminance light sources and controlling the photographing magnification. From four experiments, we show that the proposed method is an effective 3D measurement method and measurement accuracy is largely improved by three proposed solutions