2018 timing system upgrades

For 2018, there have been upgrades to the CrossMgr/Impinj RFID timing system that provide improved quality results.

  •  April 2018: CrossMgrImpinj software was upgraded to support quadratic regression (QR) analysis. This allows CrossMgr software to use 3 or more RFID chip times to calculate the time on the finish line with 1/100 second precision, yielding 6-inch accuracy at 34mph.  Prior to quadratic regression, CrossMgr used only the first time reported by an Impinj reader, resulting in finish times up to 10 feet before the finish line.  Since  Impinj RFID readers support up to 600 tags per second, individual tags can be read up to 20 times while passing the antenna, providing plenty of data to calculate a high precision time with very high confidence.
  • May 2018: RANSAC (random sample consensus) processing logic was added to improve the results of quadratic regression analysis. RANSAC analysis eliminates spurious outlier data collected from the RFID chip reader due to signal reflection.
  • June 2018: Support has been added for higher resolution cameras.
  • CrossMgrVideo software has been improved with more features for recording and reviewing finish line photos.
  • March 2018: We’ve added an ultra low light camera with an AR0130 sensor. This camera is so sensitive to light that it is used for photographing distant stars at night.
  • July 2018: In addition to the Impinj H47 tags that use the Impinj Monza 4 RFID chip and True3D dual dipole antenna, we also have more sensitive Alien ALN-9740 tags tags using the higher performance Alien Higgs4 chip. These chips provide improved performance when wet and also when moving above 30mph.
  • December 2018: In addition to the 6dbi circular patch and 14dbi Yagi antenna, we have added a 8.5dbi linear antenna. The linear antenna provides the widest field of view, optimizing the use of QR by picking up more reads at the edges of the field of view. When combined with the 14dbi narrow field Yagi, CrossMgrImpinj can optimize between antenna selections, using the high gain Yagi for distant chips and the wide field linear antenna for lower strength chips.

Comparison of RFID chip signal strength (RSSI) data points along with curves generated by quadratic regression from the same data. With only 3 chip reads, QR can closely estimate the the signal strength curve for a chip and determine its time in front of the antenna.

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