2010 Volume 72 Issue 2 Pages 133-142
In developing a stationary robotic strawberry harvester, we constructed an optical system to equip the machine with the ability to detect and determine the position and coloration of strawberry fruit. The position of the fruit was detected from below with a stereo-camera. The coloration measurement unit was set against the bed of the movable bench system at fruit level to capture images of fruit. Considering the spectral reflectance characteristics of strawberry fruit, we equipped the coloration measurement unit with red, green, and white LEDs (RGW LED) and compared it with a unit fitted only with white LEDs. The mistake rate in judging coloration was 7.1% with the RGW LED compared to 23.8% for the white LED alone. The success rate of matching the position of a detected fruit with the measured coloration of the fruit was 100%.
