Automated machine vision inspection minimises errors
Pinja has supplied two different cartridge inspection systems based on the machine vision technology to the Nammo Lapua cartridge factory. After the inspection, only the rifle cartridges that meet the quality criteria are conveyed to further processing. The first system delivered inspects cartridges for deformations and microscale cracking while the second system also measures the dimensions of cartridges in different positions.
The measuring device can be used to inspect cartridges of many different calibres. The delivery included a manipulator which can convey a large number of cartridges to inspection lines one at a time, with the base ahead. During the inspection, cartridge dimensions are verified and any deformations generated during the manufacturing process are detected. The line has eight inspection stations each measuring different things. The system pass-through is one cartridge in a second.
The solution has paid for itself three times
Earlier, all inspections were carried out visually. Each cartridge was inspected for cracks – dimensions were randomly checked. Human errors are always possible in tasks that require perseverance and attention. Since quality assessments are based on the inspector’s personal decision, the result is always in line with the inspector’s vision.
In automated inspection, this risk is avoided. The work can also be performed faster. Pinja’s machine vision solution is based on a laser pattern with 19 lines in a section of 20 mm. When a defective cartridge is found, a “dent” appears in the related line and the machine rejects the defective product. We have received an accuracy rate of 98 percent, which can be considered very good.
A machine vision inspection system that inspects both dimensions and cracks is new in the industry. Pinja’s solution creates clear competitive advantage to Nammo Lapua. The investment in automated inspection solution has also been financially profitable to Nammo Lapua. The payback period of the first system was much less than two years. A six-year lifetime means that the investment has already paid for itself three times.
Pinja’s machine vision solution is based on a laser pattern with 19 lines in a section of 20 mm. When a defective cartridge is found, a dent appears in the related line and the machine rejects the defective product.