Objective  To reduce the drop collision damages during litchi picking by robot due to improper placement and recycling.

Method  The drop collision experiment of litchi was performed. The influences of different drop collision conditions on weight loss and pericarp browning indexes of litchi were analyzed.

Result  The weight loss and pericarp browning indexes of litchi both increased with the dropping height of picking and placing and increased with the storage time. At the same dropping height, the weight loss and pericarp browning indexes of litchi were the highest when the impact contact material was PVC slab at collision. Within the scope of the experiment, it was conducive to reducing drop collision damages of litchi using the following maximum initiative dropping heights during the picking and placing process by robot: 60 cm after 2 d storage and 30 cm after one week storage when the recycling device was made from PVC plastic; 75 cm after 2 d storage and 45 cm after one week storage when the recycling device was made from corrugated board; 90 cm after 2 d storage and 60 cm after one week storage when the bottom of the recycling device was filled with litchi.

Conclusion  The research can provide guidance for developing strategies to decrease damage during the litchi picking and placing process based on robot.