1307663 is referenced by 1 patents.

ABSTRACT The present invention relates to an opto-electronic angle measurement device, methods for calibrating the device for two-dimensional angle measurement systems, as well as an opto-electronic system for simultaneous measurements of the three dimensional coordinates of a plurality of points on a surface. The angle sensor is design as a camera that includes lens forming images onto a two-dimensional array of photosensitive elements, e.g. a CCD or CID sensor. The lens has a well defined centre of rotational symmetry, giving an unambiguous definition of spatial directions, as the images of all points located in the same direction relative to this point are exactly overlapping. The angle sensors are developed to measure spatial directions towards light point sources or reflecting points illuminated by active light sources. This ensure unambiguous identification of the measured points, allows automatic use, increases the signal to noise ratio, and hence ensures high accuracy. The angle sensor is accurately calibrated using a high precision angle reference. Onto the angle sensor an adjustable mounting fixture is attached, to allow for corrections of its position relative to its centre of rotational symmetry, and to define the rotational axes. The system for simultaneous measurements of the three dimensional coordinates of a plurality of points on a surface, is comprising a system for projection of multiple point sized light spots onto a surface, and a minimum of two angle sensors. The projection system is suggested to be based on diffraction gratings made up from parallel optical fibres, each functioning as a cylindrical lens, and which yield a close to perfect diffraction pattern. An incident laser beam is diffracted by one or two gratings to multiple light beams of uniform intensity. Focusing optic is used to focus all beams onto a surface as pattern of point sized spots of uniform size. Two angle sensors, pre-processors and data processor are used to register the spatial coordinates of each light spot, and to extract the essential information from the data.

Title
Systeme optoelectronique de mesure des angles
Opto-electronic angle measurement system
Application Number
596328
Publication Number
1307663
Application Date
April 11, 1989
Publication Date
September 22, 1992
Inventor
Pettersen Alf
Rotvold Oyvind
Agent
PERLEY ROBERTSON HILL & MCDOUGALL
Assignee
Metronor
IPC
G01C 11/02
G01C 01/00
G01B 11/00
G01B 11/26
View Original Source