Lights, camera, action …
19 November 2021
When it comes to lighting options, the machine vision market is already spoilt for choice. So why did B&R choose to launch its own lighting system, asks Andreas Waldl?
Had you asked me 10 years ago, I would have said it was not necessary for an automation supplier like B&R to have its own lighting system. But, after a decade of working with machine vision, I've come to a different conclusion.
Many of the tasks we require of modern machines can only be performed when the vision system, and the rest of the machine automation, comes from a single source. Having developed our own cameras, it became necessary to develop our own lighting. Lighting is more important than the camera when considering the quality of captured images. The success or failure of a machine vision application depends on the timing, intensity and homogeneity of the flash.
Different parameters for every image
There is only one way to control most conventional lighting – a digital trigger input. Some lights also have a potentiometer to manually adjust the intensity, and there are applications where that is sufficient, but when things are moving faster, and the products being manufactured change more frequently, you need integrated lighting.
An integrated light gets more information from the control system. First, you get extremely precise flash timing – with our system, in under a millisecond – but also information like the colour and intensity needed to capture the respective product. Our lights could use different parameters for every single image if you needed, without slowing production. I know of no other lighting system on the market with such flexibility and precision.
Another benefit of tight integration is ease of use. Since all the variables from the control system are also available for vision functions, we're able to offer our customers an array of functions they can use in their familiar engineering environment. All the user need do is pick the components they require and configure them. Users can configure machine vision lighting and cameras right in the Automation Studio software.
Integration with third-party cameras
Many advantageous features of our lights work well with third-party cameras. Our lighting system can make up for weaknesses in other camera systems. Because of the sensors most cameras use, they have so much jitter that it becomes impossible to synchronise them properly with the movement of the machine's axes. It is an easy problem to solve, however: our lights flash with a precision and a minimal pulse duration of one microsecond. One of our customers takes advantage of that to get sharp images of products moving at a speed of 50 metres per second!
If system integrators choose to use their existing cameras, they must balance complex requirements. But they can use one of our standard interface modules to connect one or more B&R lights to their machine network. Each B&R light can feature up to four different LED colours.
Our system does a lot more than a conventional flash controller, which can only use hardwired external triggers and control a limited number of lights. With B&R, the bandwidth ranges from a single light to a combination of any number of lights, triggered by freely selectable variables and signals. The user can take hardware and software from B&R's standard portfolio and put together a completely flexible control solution with its own web-based user interface. This can be addressed through any communication protocol including OPC UA. And our system already supports the TSN Ethernet extension.
We have a great starting line-up on the field that can provide excellent solutions for a whole range of applications. And we’re already working on new products which we will reveal in the coming years: we've begun a very exciting journey and there's no end in sight.
Andreas Waldl is product manager, integrated machine vision, at B&R Automation
+43 7748 65860