A continuum robot, inspired by biological features, flexibly bends its body and conforms to various shapes. The high compliance and low stiffness, however, causes low rigidity and ambiguity in control when it is applied to grasping and manipulating an object. In this study, we develop a ball-jointed tendon-driven continuum robot that can bend to arbitrary directions for manipulating and grasping an object. Discs are connected by ball joints, together with coil springs coupled with tendon threads, and form a backbone of the robotic body. The continuum robot is operated to bend to an arbitrary direction by pulling the tendons using three servomotors, and returns to the original straight shape by releasing the pulling force of the contracted coil springs. The robot is constructed by using 3D-printed parts. In the experiment, the ability of the multi-directional operation was tested by bending the continuum body to specific directions, and then performing arc-following motion. Furthermore, the manipulator's grasping performance was demonstrated by preparing five objects that have various shapes, sizes, and softness. The robot successfully grasped all the objects by wrapping around them and adapting its shape to the object's shapes. The experiments verified the satisfactory operability of the continuum robot.

中文翻译：

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一种用于抓取物体的多向操作性球关节腱驱动连续体机器人

受生物特征启发的连续体机器人可以灵活地弯曲身体并适应各种形状。然而，高柔顺性和低刚度在应用于抓取和操纵物体时会导致低刚度和控制模糊性。在这项研究中，我们开发了一种球关节腱驱动的连续体机器人，它可以弯曲到任意方向来操纵和抓取物体。圆盘通过球接头与螺旋弹簧和腱螺纹连接在一起，形成机器人身体的主干。通过使用三个伺服电机拉动肌腱，连续体机器人可以弯曲到任意方向，并通过释放收缩的螺旋弹簧的拉力来恢复到原始直线形状。该机器人是使用 3D 打印部件构建的。实验中，通过将连续体向特定方向弯曲，然后进行圆弧跟随运动来测试多方向操作的能力。此外，通过准备五个具有不同形状、大小和柔软度的物体来演示机械手的抓取性能。机器人通过包裹所有物体并使其形状适应物体的形状，成功地抓住了所有物体。实验验证了连续体机器人良好的可操作性。