Design a soft gripper for vegetable harvesting in the vertical farming

• Main Author: Sim, Jared Hong Xun
• Other Authors: Phee Soo Jay, Louis
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Soft gripper
• Online Access: https://hdl.handle.net/10356/176693
• Institution: Nanyang Technological University

The focus of this project is to utilize soft robotics for vegetable harvesting. A multi-modal soft gripper has been proposed for vegetable-harvesting in a vertical farming environment. The soft gripper, made of soft and deformable material, serves as an end-effector mounted to an agricultural harvesting robotic arm. Due to the soft material’s flexibility, softness and conformability, a soft gripper is well suited to harvest and handle delicate and irregular shaped vegetables without damaging them. By utilising soft grippers, it further enhances harvesting efficiency for sustainable agricultural automation and ensure quality of produce while reducing cost of labour, where rigid body grippers may not be capable of achieving. Most commercial agricultural soft grippers are designed to harvest a specific kind of vegetable. Hence, this project presents a single, compact, multi-modal soft gripper that is capable of harvesting vegetables of various shapes, sizes, and weights. The soft gripper design is driven entirely by pneumatic air pressure and consists of two soft gripper modules. Each module comprises a middle pneumatic air channel responsible for bending deformation in the longitudinal direction and a pair of mirrored side pneumatic air channels that are angled at a thirty-degree angle and are responsible for the lateral direction deformation. This design provides a conformal grasp and allow for a better grasp on spherical vegetables. At a low actuation pressure of 50 kPa, the gripper could achieve a grasping payload of up to 200 grams. The single module, multi modal soft gripper can be used to grasp and harvest a variety of shapes, sizes and weights of vegetables. They have the potential to increase efficiency, reduce damage to vegetables and provide an automated and sustainable approach to vegetable harvesting. These benefits could tackle the increasing food demand and declining population of farmers, contributing to a more resilient and productive agricultural sector. The proposed soft gripper demonstrated the capability to grasp other objects such as food items, groceries, and eggs. This demonstrates the adaptability and versatility of the soft gripper, which extends beyond agriculture usage, and can be used in applications such as handling food and beverages or in warehouse settings.