Novel Gripper with Rotatable Distal Joints for Home Robots: Picking and Placing Tableware

A convenient situation can be realized if home robots replace housework. However, tasks in an actual home environment are challenging for robots. Particularly, cleaning the table after eating is challenging because of the cluttered environments and various tableware shapes. This study presents a new type of gripper appropriate for picking and placing various tableware in narrow and cluttered environments. The gripper comprises a 1-DOF gripper and 2-DOF distal joints. The rotatable distal joints enable reducing the effective workspace when reorientating tableware and accessing tableware in narrow spaces. In addition, the gripper can transform into three types of grasping modes by actively rotating the distal joints for handling three types of tableware, namely cutlery, cups, and dishes. The gripper is experimentally demonstrated to handle various tableware and the tables can be cleaned after eating in real-world environments.