Partial Contact Loss in Robotic Vacuum Grasping

Underactuated grippers and suction cups are two appealing solutions for industrial robots. The first one allows high adaptability to envelope the object with power or precision grasping. On the other hand, suction cups increase the payload as well as provide the possibility of unilateral grasping. The proposed gripper, named Polypus, combines these strategies to increase the range of graspable objects. Having a rigid frame, Polypus can grasp heavy objects. However, the grasping performance largely depend on the number of active suction cups. This work investigates a pick-and-place operation considering the possibility of no contact between one of the fingers or some phalanxes and the object. Numeric results highlight that depending on the object shape and orientation some phalanxes are more relevant than others. This study could be useful for fault management and mitigation.