Moving heavy objects with overhead cranes requires the operator to fasten the object to a hook with ropes or chains. This is a time-consuming process, which could be avoided by using universal grippers that can lift objects of any shape. This study was conducted to find if a universal gripper, based on granular jamming, can be used for crane scale applications. Maximum lifting capacity of granular jamming grippers was analytically evaluated and experimentally tested with various material combinations. Objects with different shapes, sizes and weights were successfully lifted with selected gripper configurations. The results showed that grain size and grain compressibility both affect the performance of the gripper. It was demonstrated that in order to efficiently lift heavy objects with granular jamming, the granular material has to be compressed sufficiently. Pressure difference between environment and the sealed pouch, filled with granular material, has to be correct. With this setup, gripper based on granular jamming was able to lift objects with various shapes; and weights up to 120 kg.
- granular jamming
- universal gripping