Flexible end-effector based on flexible pneumatic actuator and its grasping model

Taking into account the disadvantages of rigid grasping end-effectors for agricultural fruits, such as low complaisance and easy to hurt the grasping object, authors designed a type of flexible end-effector, which took three pneumatic flexible bending joints as its fingers and one flexible pneumatic torsion joint as its wrist. The mathematical models for fingers and wrist of the end-effector were presented. According to the shapes of grasping objects, the end-effector’s gripping model for grasping columniform objects and holding model for grasping spheroidal objects were analyzed in detail. Simulation and experiments were conducted to study the impact of weight and radius of the grasping object to the air pressure inside the end-effector. The results showed that the mathematical models can represent the essential characteristics of the end-effector. The flexible end-effector can be applied in agricultural fruits picking task.