NEED
Existing bowling alley pin fall detectors used moving mirrors and light beams
to detect the pin fall data. The beams had to be adjusted to detect different
types of bowling pins such as candle pins, duck pins, etc. Accuracy was not as
high as with new technology, which measured the actual pin dimensions and
locations.
Since a single beam was used, even in newer Charge Coupled Device (CCD)
systems, the existing pin fall detectors could not measure pin dimensions. In
addition, there was no easy way to check accuracy and repeatability against
known standards.
SOLUTION
Mitsi developed a custom CCD camera and processor card to measure the heights
of pins and to check for proper pin locations.
A liquid crystal display (LCD) calibration system was designed and produced.
This system allowed the service technician to see actual pin fall data. An easy
to use menu driven setup program prompted the operator to make all adjustments.
A data logging computer was also designed. This computer stored the results
on disk and on tape. The video pin fall detector data was compared to the
mechanical switches and differences logged. Mitsi engineers could rapidly play
back thousands of games and compare the video output with the mechanical
switches. Fine tuning of the algorithms could be done quickly.
RESULTS
Over 20,000 pin falls were compared with the switches, with results exceeding
requirements. Certification was then applied for and received from the American
Bowling Congress. The CCD camera and pin fall detector are now in high volume
production.
