Improved Mechanical Design and Simplified Motion Planning of Hybrid Active and Passive CableDriven Segmented Manipulator with Coupled Motion Cabledriven segmented manipulators (CDSMs) featured by superior dexterity, light and slender body are excellent candidates for operations in confined environments. However, the stiffness and load capacity of such manipulators have been a challenge due to their structural elasticity. In this paper, we propose an improved mechanism design based on the preliminary work to enhance the linkage accuracy and arm continuity without sacrificing the dexterity, high stiffness and load capacity of CDSM. The manipulator is composed of 4 improved hybrid activepassive linkage segments. Its short and long linkage cables with pretension mechanism are designed to keep equal angles of adjacent joints. An improved separable small driving control box is also designed with both quick release and load mechanism and stroke amplification mechanism. Then the size of control box can still remain small, even the number of segments and the joint limit angles increase. Considering the improved insegment linkage characteristic, traditional kinematic equations and Jacobian matrix are greatly simplified with DenavitHartenberg (DH) method. Further trajectory tracking planning based on the simplified kinematics solved the Cartesian space planning for task design. Finally, a prototype system is developed to perform the linkage accuracy and comprehensive obstacle avoidance experiments. Experimental results show that the developed hybrid active and passive CDSM has relatively high accuracy and super dexterity.

A Kinematic Equivalence Trajectory Planning Method of Hybrid Active and Passive CableDriven Segmented HyperRedundant Manipulator * A hybrid active and passive cabledriven segmented hyperredundant manipulator is very flexible and dexterous to conduct tasks in highly cluttered environment. However, computation load of inverse kinematics and trajectory planning are also very large. In the paper, a kinematic equivalence method is proposed for the hybrid active and passive cabledriven segmented hyperredundant manipulator to overcome the above challenge when the position and direction of endeffector are considered. The kinematic equivalence method is an effective way to solve the inverse kinematics and trajectory planning by simplifying and rearranging joints of each segment. The mechanism and joint layout of the manipulator are first analyzed. Then, the kinematics model is established by both traditional DH method and kinematic equivalence method. The calculated amount is decreased by reducing the number of rotation axis that needs to be processed in each segment. Furthermore, the desired trajectory is generated for the end effector of the arm to approach the target point. Finally, the proposed method is applied to a practical prototype, which has five segments and each segment consists of six subsegments. Simulation results verified the proposed method.