Machine vision improves the measuring process of precision and micro components
HALCON | Matching | MeasuringThe precise inspection of very small precision components, for example in watchmaking, is a challenge. Petitpierre, the Swiss specialist for high-precision technology, has developed sophisticated applications with which micromechanical components can be cleaned and measured precisely during the production process. MVTec HALCON supplies the appropriate machine vision algorithms for this: Technologies, such as matching and contour extraction, ensure precise measurement results.
Measuring and inspecting super-small parts repetitively, precisely, and at high speeds are key requirements for the watchmaking industry as well as all industries dealing with micro components, as they help to avoid production rejects and to produce precise pieces.
Petitpierre SA, headquartered in Cortaillod, Switzerland, is a specialist in sophisticated microtechnology that committed itself to making this ideal a reality – with the help of machine vision. Founded in 1973, the family-owned company’s portfolio includes complex measuring applications for the watchmaking, jewelry, medical, and aerospace industries. The company also develops and produces high-precision systems for the automated assembly of high-end microtechnical components as well as sophisticated watchmaking tools.
One of Petitpierre’s customers is KIF Parechoc, a flagship company in the Swiss watchmaking industry. To comprehensively improve and automate their processes, Petitpierre developed a contactless inspection and cleaning system for precision mechanical components. To elevate the quality of the processes to a new level, the objective was to optimize the measuring of these parts. The major challenge was to perform a highly precise and fast series of measurements under harsh production conditions with just one click. This challenge could be overcome with MVTec HALCON.
Process relocation from the clean room to the production facility
In the past, several systems carried out these measuring processes, including contact measurement, in a clean environment. Now they were to be moved directly to the production plant to reduce the effort and ensure continuous process chains. Advanced measurement technology was needed to meet the diverse requirements. Machine vision not only made it possible to automate the entire process seamlessly with minimal effort, but also increased speed and precision in the measuring process.
Efficient combination of cleaning and measuring – lumen and drop powered by machine vision
The solution implemented by Petitpierre is a dual system, combining its products drop and lumen and empowering them with machine vision software. Drop is a device for the automatic cleaning and drying of precision parts that ensures the optimum repeatability of cleaning quality. Lumen is a telecentric optical device for the intelligent, automatic, and highly accurate measurement of precision micromechanical parts. In the first step, the components are being cleaned and dried in drop, then transferred to lumen via a vacuum gripper. There, the integrated machine vision software detects them automatically and measures them. Once all parts have gone through the measuring process, the measurement results are seamlessly exported into the KIF Parechoc quality control software, where they are available for the rest of the process chain.
High-precision measurement thanks to matching technologies
MVTec HALCON is used as the machine vision software within the system. Its shape-based 2D matching technologies can identify and locate the tiny parts precisely so that they can be picked up with the vacuum gripper and measured with sub-micrometer precision. In detail, diameters, lengths, concentricity, radiuses, and angles are measured and inspected with subpixel accuracy, using the technology “subpixel threshold”. In addition, MVTec HALCON facilitates the precise camera calibration of the lumen system.
Precise mapping of telecentric optics with HALCON
Another advantage: MVTec HALCON is able to meet the special requirements of telecentric optics – as used in Petitpierre’s lumen system – with precision right out of the box. The 360-degree measurement of the object means that there is no perspective distortion that would involve time-consuming corrections afterwards. This paves the way for a particularly high level of measurement accuracy.
Fully automated, much faster, and more accurate: all goals achieved
“MVTec HALCON is the ideal machine vision software to overcome the challenges we were facing. It not only offers the required accuracy and speed of detection, but also enables inspections that are completely contactless. Since we can now start the whole inspection process with a single click, we reached the goal to make it much faster. As a result, KIF Parechoc is able to cut costs and raise productivity to a new level,” concludes Thomas Majoulet, Head of Metrology at Petitpierre.