Case Studies

vision inspection

High-Speed Pharmaceutical Vision Inspection

Posted in LabVIEW, Machine Vision, Manufacturing Automation and Intelligence, Motion Control, Pharmaceutical & Medical, Test & Measurement Automation

Summary

DMC developed an eight-camera vision system to integrate with a pharmaceutical pill manufacturing system. The vision system used National Instruments’ Embedded Vision System and Basler Ace cameras to inspect each pill in order to verify that the pill was not cracked or damaged, preventing the delivery of an incorrect dosage to a patient through a cracked pill. 

pharmaceutical pill

Undamaged Pill

Solution

DMC’s system utilized NI hardware to integrate with the existing Delta Tau Motion Controller. The NI cRIO was used to determine pill presence, track pill results from the EVS, and output results to the Delta Tau Motion Controller in order to reject bad tablets. The NI EVS triggers the cameras and lights, acquires images, runs inspection algorithms, and outputs a result to the cRIO. Each camera views two tablets, so pass-fail results are determined for 16 tablets nearly simultaneously. The first step of the inspection algorithm is to separate the pills from the background, then each individual pill is analyzed using three algorithms:

  1. Check for bright spots within the interior of the tablet (the outside of the tablet is darker than the powdery inside of a broken tablet).
  2. Compare the perimeter of the tablet to the ideal perimeter of a known, good tablet. The perimeter comparison allows for rotated and flipped tablets. This check will reject broken tablets that don’t have any white powder visible to the camera.
  3. Check the gradient of pixel brightness a few pixels inside the perimeter of the tablet. This check finds hairline cracks that are not large enough to be detected as a contiguous blob of brightness.

The results are tracked in the cRIO until the pills reach the rejection point on the machine, at which point the results are sent to the Delta Tau controller and the bad pills are blown into a reject container.

Customer Benefits

  • Full inspection of all pills ensures that no patient receives an improper dosage, reducing the liability of the pharmaceutical manufacturer.
  • Inspection using eight cameras simultaneously allows maximum throughput of the manufacturing line at up to 144,000 pills per hour.
  • Compact size of Basler Ace cameras requires minimal space inside the pill sorting.
  • National Instrument’s robust industrial real-time platforms (cRIO and EVS) allow for maximum uptime.