Optimal Vibrating Speed of Jigsaw for Harvesting High-Bush Blueberries in Japan（Extracts）

High-bush blueberry does not mature all fruits at once，so it needs to be selectively harvested 3-5 times over 3-4 weeks.The new developed blueberry harvesting method employs a jigsaw，which has five dials for speed changing with a fixed stroke 18 mm，to vibrate branches for separating blueberries in Japan.In order to find out the optimal speed（dial）that can remove more ripe blueberries while less unripe blueberries efficiently，a high-speed camera was applied to record harvesting process of blueberries.Then，details of the process were collected by replaying recorded videos.After that，the optimal vibrating speed and vibrating time was determined with statistical analysis.By analyzing the five speeds，dial 2 with the speed of 1670 cpm was chosen as the optimal speed of jigsaw to vibrate each branch around 2 seconds.In that condition，it separated 87% ripe blueberries which is the same to the three high-speed dials，but only removed 24% unripe blueberries that is not significantly different from dial 1.