In the field of grasping application, continuum robots are characterized by flexible grasping and high adaptability. Based on research on the physiological structure and winding method of seahorses, a continuum robot with a helical winding grasping function is presented in this paper. The continuum robot is driven by cables and uses a new flexural pivot with large deformation as a rotation joint. Firstly, based on the Serret–Frenet frame of the spatial cylindrical helix, the helical winding continuum robot is modeled and solved. The change rules of parameters such as the rotation angle of the joint and the helix parameters under the helical winding method are derived. Then, the compliance matrix of the joint is solved using the structural matrix method, and a stiffness model is established to analyze the relationship between the load and deformation of the continuum robot. The kinematics model of the continuum robot is established by using the modified Denavit–Hartenberg parameter method. The static model of the continuum robot is solved by vector analysis under the condition of considering gravity, and the relationship between the length change of cables and joint curvature is obtained. Finally, the stiffness model and static model of the continuum robot are verified by simulations and experiments. The test results show that within a certain radial range, the continuum robot has the function of helical winding and grasping for objects. Compared to the previous imitation seahorse tail robot, the helical winding structure not only provides a larger grasping area compared to in-plane form but also achieves a better bionic effect.
Journal of Mechanisms and Robotics Open Issues