Abstract: A novel deformable rolling mechanism with the geometric configuration of the truncated hexahedron is proposed. The rolling mechanism included sixteen links and twenty revolute joints is a spatial closed-chain linkage. A new design method chosen the regular triangle linkage as the basic construction unit is adopted to design the rolling mechanism. The rolling mechanism has the deformable and rolling capabilities, and its turning motion is controlled by using its singularity position. The screw theory is used to calculate the degree-of-freedom of the configuration. By applying the 3D model and dynamic simulation model built by Solidworks and ADAMS respectively, two deformation manners, stationary deformation and movement deformation, are analyzed. The maximum deformable compression ratio is obtained and the feasibility of its deformation and turning motion is proved. The tumbling condition is discussed and critical value is calculated by the kinematics and stability analysis. A prototype is fabricated to testify the two deformation manners and rolling capability, and achieve the expect results. Furthermore, the polyhedron rolling mechanism has a high structural stiffness, easy to increase the carrying capacity of the robot.

Key words: Polyhedron, Rolling mechanism, Screw theory, Shape shifting