Can your vision system see in the dark or in 3D?

Vision systems struggle on applications where for example black components are on a black tray, because there is too little contrast between the components and the background. A large and unpredictable variety of colours, for example checking the contents of a tote box in a warehouse can also be problematic and this is when 3D measurement offers a better solution. Unlike the two dimensional view of a vision system, Leuze electronic's new LRS & LPS sensors use distance measurement which gives a third dimension. Measuring position rather than interpreting shades or colours also makes them much more immune to differences in brightness, colours and ambient lighting – In fact they will happily work in the dark. The sensors use a highly energetic laser to illuminate a 'slice' across an object, so that each point is illuminated to a factor 1,000 times greater than the lighting from a vision system, without risk to an operator's eyes. The sensors project this laser line up to 600mm long across a section on the x-axis, which when combined with an encoder input to the sensor for the y-axis, enables the sensor to measure not only the location of each pixel in an x/y co-ordinate system, but also its brightness value and the distance in the z axis. The LRS sensor is programmed using a pc to set fields of interest and Boolean logic to monitor for example if a tote bin is empty, half-full, full, or overfull, each option being output as 24v on one of four outputs – in effect a very clever but simple to set up detection sensor, ideal for an end-user. The LPS sensor is designed for measurement, once again being easily programmed, but outputting a data stream of accurate 3D measurements, making it a solution more typically for a system integrator or machine builder. A video of it on a bin-picking robot is at www.leuze.co.uk These sensors are equivalent to using an array of 376 laser distance measurement sensors, which are perfectly calibrated the moment they are switched on - The sensor will even handle the complexity of working with up to 5 other such sensors to profile a log or a complete pallet load for example. PS – Leuze electronic are running FREE machine vision training workshops on 11th & 12th October at the PPMA's offices in Croydon, or at Leuze electronic in St Neots. – More info on www.leuze.co.uk