End-Effectors Developed for Citrus and Other Spherical Crops

Abstract

Citrus harvesting is time-intensive and labor-intensive, relying mainly on manual harvesting. The automatic harvesting of fruit and vegetable crops can not only reduce the physical labor of fruit farmers in the harsh field environment but also greatly improve the harvesting efficiency. Based on the principle of manual citrus picking, an end-effector with three-finger grasping is designed in this study. First, the structure of the end-effector was designed to achieve the function of stable grasping and effective cutting of citrus fruits, and then the working process and key parameters of the end-effector were explained in detail. Finally, a picking test was conducted without considering robot vision. The test results show that the end-effector has a picking success rate of 95.23% for citrus with a diameter of 30–100 mm and an average picking time of 4.65 s for a single fruit. This end-effector can realize the picking function for citrus of different sizes and shapes and has the advantages of high adaptability, stable gripping and no damage to the fruit.

Research Progress on Low Damage Grasping of Fruit, Vegetable and Meat Raw Materials

“…The results show that the flexible gripper is capable of the non-destructive grasping of tomatoes with a diameter between 65 and 95 mm, and can withstand a tensile force of 7 N, with a load of more than twice its own weight. Xiao et al [ 15 ] designed a fin-shaped flexible three finger grasping end-effector, as shown in Figure 6 . Its structure mainly includes: 1. connecting chuck, 2. fixed bracket, 3. clamping fingertip, 4. moving linkage, 5. stepping motor, 6. blade fixed frame, 7. cutting blade, and 8. clamping finger.…”

A Comprehensive Review of the Research of the “Eye–Brain–Hand” Harvesting System in Smart Agriculture

“…Researchers categorize the end-effector grippers into four major types: negative pressure adsorption end-effectors; shearing-style end-effectors; negative pressure adsorption end-effectors; cavity retrieval end-effectors; and flexible grasping end-effectors. [10,[34][35][36][37][38][39][40][41][42][43][44][45]. The selection of an appropriate end-effector gripper is determined by the physical characteristics of the fruits, such as their types, sizes, and the hardness of their peels.…”