Automated combination of image processing and tactile monitoring minimises wastage

A combination of image processing and tactile gauge units can be the solution for continuously checking products.

The company Vosseler Umformtechnik can look back on more than 80 years of tradition in cold and hot metal working. To satisfy their customers' high requirements for quality, they settled on automated monitoring. That's because only complete monitoring and precise inspections minimise wastage and manufacturing errors, save costs, minimise returns, and meet the high demands of customers.

A typical inspection by trained employees is, due to the human factor, limited when it comes to large batches. In addition to the expenditure, it's not uncommon for the mental state of the employees to determine the quality of the batch. However, continuous product inspection is essential for safety-related components.

A combination of image processing, which has been implemented by SSR-Technik GmbH, as well as tactile gauge units are available as a solution. Along with the control mechanism of image processing, the additional control factor of tactile actions takes on the additional aspects of quality control which cannot be performed through a purely visual inspection. This automated solution achieves continuous quality control in cooperation with efficient transport technology. Mechanical components are inspected individually. The visual inspection comes after storing the components in v-blocks on a rotary unit. Subsequently, the tactile inspection is taken on with a mandrel or a ring. After these values are determined, the components are sluiced and sorted by whether or not they passed the inspection. This is done at a delivery rate of 30 components per minute.

Challenges of image processing

This process has shown lighting to be a challenge for application. The safe illumination of the ball surface by reflected light is implemented through the adaptation of vicolux® to meet industrial needs. The pictor® smart camera is used for the inspection in conjunction with the vcwin software. This scalable combination continuously satisfies requirements in the field of automation. The pictor® system offers a heavy-duty combination of picture recording and analysis. The necessary analysis algorithms have been optimally developed by vcwin. The software has numerous touch and analysis tools, which allow for a structured approach, especially in the sense of end user-friendliness.

During a short training course, the employee is quickly able to independently make changes to parameters on existing analyses, and to create new analyses.

Analysis features

Approaches for analysis in the described case for image processing have been made possible in the following ways:
 

•     Detecting cavities,
•     Detecting internal and external shape degrees,
•     Detecting spherical impressions in the range of 0.01 mm,
•     Detecting thread completeness,
•     Detection mechanical residue in the entire threading process,
•     Thread stopping behaviour,
•     How residue free and undamaged the base of the bore hole is,
•     How residue free the through bore is.

Approaches for analysis in the described case described in the area of tactile gauges have been made possible in the following ways:
 

•     Identification of adequate thread depth.
•     Identification of thread gauging ability,
•     Suitability of the cylinder diameter (external and internal).

The results are displayed both as individual figures and in good/bad statements.

published in: inspect issue 4_2018