3-D vision systems using rotating 1-D sensors

This paper describes continuing research with both two-dimensional (2D) and three-dimensional (3D) rotating line-scan vision systems in industrial inspection and control automation. Traditionally, two-dimensional line-scan systems have been effectively used in a production line environment where movement is inherent in the application. However, when only using a single sensor, depth or range information cannot be ascertained from points of interest in object space. The research outlined in this paper describes how omni-directional range data from a scene of interest may be obtained when utilising a rotary 3D arrangement of line-scan sensors. The ability to resolve range information allows the location of any point to be determined within the field of view surrounding the camera arrangement. An advantage of a rotating line-scan vision system is that the field of view (and thus the resolution) of an image can be varied from any arc up to 360°. If an “all-round” field of view is set up, the images produced will contain information from an area of the object space completely surrounding the camera arrangement. This field of view may then be adjusted to cover a smaller arc and used interactively with the image start point. The resultant images can then display information at a given resolution from any part of the observed object workspace surrounding the rotational configuration. An obvious benefit of such a versatile system is, for example, the simultaneous control of a number of robot arms located around the camera arrangement. This paper presents results pertaining to the 2D and 3D aspects of the rotating line-scan research, including the potential accuracy of the system over a variety of stereoscopic configurations. This demonstrates the use of the line-scan system in specific applications where conventional sensor modalities may otherwise not be appropriate