Development of Tendon-Driven Continuum Robot with Visual Posture Sensing for Object Grasping

Inspired by the characteristics of living organisms with soft bodies and flexibility, continuum robots, which bend their robotic bodies and adapt to different shapes, have been widely introduced. Such robots can be used as manipulators to handle objects by wrapping themselves around them, and they are expected to have high grasping performance. However, their infinite degrees of freedom and soft structure make modeling and controlling difficult. In this study, we develop a tendon-driven continuum robot system with color-based posture sensing. The robot is driven by dividing the continuum body into two parts, enabling it to grasp objects by flexible motions. For posture sensing, each joint is painted in a different color, and the 3D coordinates of each joint are detected by a stereo camera for estimating the 3D shape of the robotic body. By taking a video of the robot in actuation and using image processing to detect joint positions, we succeeded in obtaining the posture of the entire robot in experiments. We also robustly demonstrate the grasping manipulation of an object using the redundant structure of the continuum body.