EXCELLENTLY TESTED – inVISION

Optical field cameras to inspect front/rear bumpers

Thanks to the LumiScan VGR vision-guided robotics software, high-resolution vision systems allow combining different image processing applications and analysis methods together with robot control. The example of a front and rear bumper testing system from Mühlbauer Technology shows what this looks like in practice, where a system has been developed consisting of LumiScanX light field cameras and software.

One of the robotics programmers at Mühlbauer Technologie defines the task as follows: “Our requirement was for a simple, intuitive and clear software solution that would work outside of a standard bin picking application. This was the first time we had a testing system for the front and rear bumpers. Currently, the camera system and software are used in Essential for production and radar capability testing of automotive exterior components Light Field Systems and Two LumiScan Spot Pattern Display Units The complete system uses light field technology, which effectively reduces reflections, glare and occlusion, resulting in better, more high-quality spot clouds on bright painted bumpers It makes it possible, for example, to determine the type of component and determine its precise position in space, as well as to detect any possible deformation of loose components.

Robot path and camera position

The robot interface required for this application was developed in collaboration between developers from HD Vision Systems and programmers from Mühlbauer Technologie. The corresponding correction of the robot's path is performed in order to reach all relevant test points on the surface of the live component with the robot. This ensures that measurements are taken in the correct place, even with crooked parts. All these calculations – including determining the robot's path – are performed by the software in fractions of a second. One of the most important decisions was camera placement. In the first concept, two camera systems were mounted statically, bringing advantages in terms of cycle time but limited flexibility in terms of component variation. In current concepts, camera systems are mostly guided by an inspection robot in order to maximize area coverage and flexibility. Since images are always taken from the painted surface, the images are highly dependent on the exposure setting of the camera. The systems are therefore designed in the form of closed booths to create constant lighting conditions, regardless of the time of day or hall lighting. Highly reflective and dark component types were the most difficult to detect. The solution was to combine several image recordings. To improve the performance of 3D light field cameras, each camera is supported by LumiScan Spot style projectors. All collected data is processed in the LumiScan VGR, whose main task, in addition to precise measurement of components, is to check whether the generated robot path is in the safe zone and completely free of collisions. Depending on the result, the path coordinates are recalculated.

Adapting to new components

Many customers have high variation in their component portfolio and require easy integration of new components into their test systems. The HD Vision system solution enables the use of simplified component storage for multiple similar components, such as front or rear bumpers. Component support can be set in different parameters. This eliminates the need to purchase additional hardware to integrate new components, as they can be trained at the software level only. With a direct connection as a ProfiNet slave to the robot and a specially adapted interface, HD Vision Systems has created a system solution that is already successfully operating in thirteen test systems at home and abroad.

www.hdvisionsystems.com