Posted to News on 1st Jun 2007, 15:25
Machine vision software operates with laser triangulation
Firstsight Vision is now offering a new set of tools designed primarily to measure the height of objects in machine vision applications using laser beam triangulation. These new laser measurement tools form part of the latest Sherlock 7 machine vision software from ipd and further extend its comprehensive range of capabilities for automated inspection applications. The new tools can also be applied to the inspection of any component that has a bright or dark line-like structure, even if it is not generated by a laser. The new tools are laser height, laser caliper, laser line and laser points.
The laser height algorithm measures the height profile of an object along a laser line using laser triangulation. An extremely simple set-up routine requires only the measurement of three known heights. According to Firstsight Vision, unlike other systems, the geometry of the laser-object camera does not need to be measured. It is claimed that the new approach can be 5-10 times more accurate than existing 'laser approximation' methods. In addition, the algorithm can suppress reflections from shiny components such as those made from metal.
Other laser tools allow various parameters of the laser line (or other straight lines) to be determined. The laser caliper measures the line width and edge positions to allow the centre of the line to be calculated accurately. The laser line tool fits a line to a near-horizontal or vertical line using a 'least squares' fit, having first removed any data points far outside the norm. Both of these tools are particularly useful on noisy (or 'speckled') lines. The laser points tool gives the side and centre positions of the line.
The versatile Sherlock automated quality inspection tool offers the flexibility to adapt to changing inspection needs and can be used in mono, colour and multi-camera applications. In addition to the options of ipd's integrated compact vision appliances, or NetSight II compact vision system, Sherlock is compatible with a range of cameras using a PC/framegrabber platform. It is compatible with analogue, CameraLink (area or linescan), FireWire and Gigabit Ethernet cameras.
