Motion and Driving Characteristic of Elbow-inspired Tensegrity Joint for Bionic Robot Arm

In an open environment, the time, direction and magnitude of the external collision or the dragging on the robot arm are unpredictable. Therefore, it is necessary for the cooperative robot joint to have mechanical flexibility to passively absorb a small amount of external displacement and vibration. Tensegrity is an excellent option to realize flexible joints. This paper focuses on expanded octahedron tensegrity(EOT) elbow joint and compares it with our modified version. By means of simulation and prototype experiment, the performances of two joint designs including range of motion(ROM) and driving tendons’ tension are studied and the relationship between function and structure are analyzed. The results showed that our version has greater ROM and relatively lower tendons’ tension. The conclusions and analytical methods used in this paper are of reference significance for the design and performance study of tensegrity joints.