Development of pneumatic four blade soft grasp for grabbing strawberry

Abstract:

The increasing demand for automatic picking robots of fruits and vegetables drives the study of the end-grabber realizing non-destructive picking. However, most traditional end grips are rigid structures, and the existing flexible grips also have shortcomings such as insufficient grasping force and poor coating. A new type of pneumatic four-blade soft grip was designed to realize the non-destructive picking of strawberry, which used the contour curve of strawberry as the design curve for the first time. Firstly, the structure of the software grip was simulated and optimized, thus an idea of safely attaching to the target surface was put forward. Then, both the minimum failure stress on surface of the strawberry and the end force of the software grip were test, and the feasibility of nondestructive grasping was verified based on these results. Thirdly, the bending deformation law of the soft grip leaf surface was studied using the dynamic capture technology. Finally, the soft gripper with arcs gas channel of strawberry grab was used to test the actual grasping ability. Results showed that the four blade pneumatic gripper soft could realize nondestructive fetching, the success rate was 90%, and the damage rate was 2%. It is proved that the developed four gripper for strawberry scraping blade soft has a good stability and practicability, and can be used to strawberry picking at the end of the actuator. This study can also provide theoretical basis and technical support for the picking technology of other fragile fruits and vegetables.