In nearly all machine-vision systems, the choice of lighting and illumination methods is crucial. If not properly illuminated, the system cannot perform the image-processing operations to discern object features such as missing labels and cracks. As most systems integrators know, the choice of lighting is very much application-dependent. Moreover, each new machine-vision task may require a new lighting method.
Developers often choose their lighting devices independent of the machine-vision system and integrate the lighting, power supplies, and lighting controllers into PC-based systems. Thus, not only must designers integrate separate machine-vision and motor controllers into the system, but they must also develop integrated lighting solutions. Often, three or four separate systems must be independently controlled using a graphical user interface (GUI) on the host PC.
To ease the systems-integration task, many companies are integrating data acquisition, control, and machine-vision functions into their user interfaces. At the International Robot & Vision Show (June 2001), Meta Controls (Morrisville, NC) demonstrated a set of FireWire cameras and motor controllers running under the same user interface (see p. 8). Also at that show, Omron Corp. (Schaumburg, IL) announced a joint venture with CCS America (Waltham, MA) that controls CCS's range of light-emitting diode (LED) illumination products automatically from either the Omron F-150 or F-160 series of machine-vision sensors. Alternatively, both the F-150/160 and LED lighting products can be preconfigured on a host PC using Omron's Vision Composer Software.
Omron displayed the intelligent lighting option along with the F-160 vision sensor. To link camera, vision sensor, and intelligent lighting adapter, a proprietary interface transfers RS-170 video data to the camera as well as serial lighting control data. "Using a purpose-built intelligent lighting adapter," says Mark Sippel, a vision product marketing manager at Omron, "allows the range of LED lighting from CCS to be controlled in a number of different ways."
It is likely that other vendors will follow suit. Expect, for example, vendors of machine-vision and data-acquisition products to offer combined data-acquisition/control and image-processing packages under single PC-based graphical user interfaces.