A 3D-Printed Robotic Gripper with Embedded Sensors for Stiffness Identification and Grasping of Fruits and Vegetables

The agricultural sector is worth around 900 billion dollars from its product revenue and it is expected to grow even further to reach around 4 trillion dollars. Unfortunately, around 20% of its worth is lost due to the harvest of unripe fruit or the damage caused on them during harvesting. Would there be a possible solution to this problem using the advancement in robotics? We are proposing a soft robotic gripper for harvesting fruits and vegetables to address this problem.

Robotic grippers have offered a multitude of benefits to many work fields as they offer better precision in object handling, as well as decreasing the time and cost it would require using manual labor instead. In the agricultural sector, it is necessary to map out exactly the design, control, and material of the robotic gripper, as some types of fruits and vegetables require delicate handling since they get damaged due to their softness. Our project focuses on the design and implementation of a three-dimensionally (3D)-printed robotic gripper that can safely grab fruits and vegetables depending on their nature and ripeness. The gripper integrates soft pneumatic sensing chambers and a camera to identify the level of ripeness of the fruit or vegetable that needs to be grabbed. The combination of the sensing signals from the soft chambers and the computer vision analysis allows the gripper to identify the stiffness of the fruit or vegetable to exert the right amount of pressure/force before grasping depending on the level of ripeness. Once the stiffness is identified, a negative feedback control system allows the gripper to safely grasp to object by relying on the soft chamber pressure data as the sensing (i.e., force data). Our gripper imitates the process of ripeness identification by humans where they first gently touch a fruit or vegetable to assess its ripeness and then grasp it based on its ripeness level. This gripper has potential applications in fruit and vegetable sorting based on ripeness (e.g., tomatoes), fruit and vegetables harvesting, and biomedical applications where the stiffness of a certain organ or limb must be identified by a robot.

Project Details

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