| 摘要 |
PURPOSE:To detect the position of a moving body without an accumulated error due to the movement by receiving light emitted from plural fixed light sources by a conical reflector set up on the moving body and a photodetecting element and measuring an optical image position corresponding to the distance and angle from the fixed light sources. CONSTITUTION:Light from the light sources 4 (4a, 4b) is projected to the conical reflectors 3 on the moving body 1 and the reflected light is projected as an optical image 12 corresponding to the distance and angle from the light sources 4 on the photodetecting element 2 set up at the lower part of the reflector 3. If it is defined that the height of the reflector 3 is (h), the radius of the reflector 3 is (r), the distance between the apex of the reflector 3 and the plane of the photodetecting element 2 is (f) and the length of the optical image 12 projected on the photodetecting element 2 is L, the distance (l) between the apex of the light sources 4 and that of the reflector 3 is found out by using l=rf+Lh/L-r from the length L of the optical image 12 on the basis of the similarity of triangles. Thus, the coordinates X and Y are obtained by said equation. |
