Designing and Developing of a Pick and Position Mechanism for Spherical Shaped Fruits

The objective of this research was to design and develope a Pick and Position system to displace spherical-shaped fruits, with minimum damage to flesh, from one specific place to another. A mechanical gripper (end-effector) suitable for grasping spherical-shaped fruits with 5-9 cm in diameter was designed and developed. The primary goal of the gripper design was to take and release the fruit without bruising it in a specified time sequence. A slider-crank mechanism was used to drive the gripper. To achieve suitable timing in gripping and releasing of the fruit, the slider was driven by a cam. The kinematic and dynamic analysis of the gripping unit was done and its motion was simulated using Working Modwl software. In the next step, a four-bar mechanism (arm) was designed and developed to displace gripper between two specified locations. After kinematic analysis, equation of motion of the arm mechanism was derived and its dynamic analysis was performed. The gripper was assembled on the arm mechanism and the performance of the gripper and arm mechanism was investigated. It was observed that the system had the ability to pick and release the oblong fruits, such as apple, between two specified locations. The performance of the system for larger size fruits could be improved by some modifications on the gripper fingers.