Stereo Deflectometry Vision System Inspects Glossy Parts

Glossy surfaced parts are typically inspected manually by humans due to lack of automatic tools to date. These products are often produced in large quantities making the inspection work extremely difficult and monotonous due to the large volume and fast pace. This leads into quality deviation caused by inspection process or workers. With the Helmee CSD the level of inspection acceptance in can be programmed.

Helmee’s visual inspection solution can handle chrome plating, painted, matt, satin, and cast iron parts. The solution performs with high accuracy delivering high speed inspection. One application example is door handles being inspected in only 7 seconds; usually this tasks would take 30-60 seconds using human operator visual inspection.

The Helmee CSD inspection unit dome covers the part when performing the inspection task. The dome spreads light equally to part surface working as a diffuser. By changing the dome, Helmee can control the amount of the light going through. The dome also collects light reflections from the light surface. Typically parts have curvature which means the light reflects to multiple directions with reflections captured by the dome.

The system uses multiple cameras, typically three in order to capture reflections using multiple viewpoints thereby enabling 3D shapes to be inspected. While having different view points the three cameras overlap each other to ensure the complete surface inspection is covered. With multiple cameras the system is also able to simultaneously observe different sides of the parts.

The Helmee CSD inspection system uses deflectometry technology. Sinusoidal light patterns projected as waves revealing defects on the surface of the part. Deflectometry amplifies the light waves making even the smallest defects visible by the system. The high-resolution, high-speed cameras are Helmee’s own optical arrangement, which is part of the Helmee CSD (Covered Stereo Deflectometry) technology. The other part of the CSD is the bespoke software, which can create models of the surface properties, such as shape and reflection quality in addition to the typical grey-scale images from the cameras. For illumination the system uses a special long life light projector based on lasers, leds and micro-mirror technology. The system software includes all the tools and features needed to operate, report, analyse the inspection process and to teach new parts to be inspected with no programming needed.

The Helmee CSD is integrated into a robot cell using either industrial or collaborative robots. The robots move the parts to the inspection system’s field of view and subsequently sort them according to the inspection result. Helmee’s robotized CSD system can inspect over 10 million parts a year.

For more information: www.helmee.com