Latest Papers

ASME Journal of Mechanisms and Robotics

  • Design of Reconfigurable Articulated Walking Mechanisms for Diverse Motion Behaviors
    on March 20, 2025 at 12:00 am

    AbstractLegged robots are able to move across irregular terrains and those based on 1-degree-of-freedom planar linkages can be energy efficient but are often constrained by a limited range of gaits which can limit their locomotion capabilities considerably. This article reports the design of novel reconfigurable parallel linkages that not only produce different walking patterns but also realize behaviors beyond locomotion. Experiments with an implemented wearable device able to guide the lower extremity through multiple human-like walking trajectories are presented and the preliminary results validate the proposed approach.

  • Modeling, Kinematics, and Dynamics of a Rigid-Flexible Coupling Spring-Cable-Driven Parallel Robot
    on March 20, 2025 at 12:00 am

    AbstractConventional parallel robots are made of rigid materials for the purpose of fast and accurate localization, exhibiting limited performance in large-scale operations. Inspired by the softness and natural compliance of biological systems, this article proposes a rigid-flexible coupling cable-driven parallel robot. The concept of flexible cable and spring hybrid and working principle are introduced. The kinematics of single module and multiple modules connected in series are analyzed and equations are given, and the Lagrange equation is used to establish dynamic models. Finally, two methods are used to validate the kinematics and dynamics. One is to draw the specific structure with the posture of the end-effector and measure the cable length to compare it with the analytical solution in the kinematic model. The other is to build the structure and joint characteristics in simulink, given the posture of the end-effector and the external force/torque, the cable length and the force applied are compared with those obtained from the dynamic model. The reasonableness of the mechanism and the feasibility of the kinematic and dynamic models are verified.

Development of a Novel Tendon-Sheath-Driven Upper Limb Exoskeleton With Elastic Joints for Assisting Surgeon-Performing Microlaryngoscopic Surgery

Abstract

When performing microlaryngoscopic surgery, surgeons must maintain their arm positions for a long time, which can cause arm soreness and affect the success rate of surgery. In this study, a novel tendon-sheath-driven upper limb exoskeleton with elastic joints (TULEE) is proposed and developed to support the arms of doctors wearing the TULEE. The functional requirements of the TULEE were proposed according to the needs of microlaryngoscopic surgery, and the overall structure of the TULEE was designed. Then, the positive kinematics of the TULEE were derived based on the D–H transformation matrices, and the accuracy of the positive kinematic control was verified experimentally. The reachable workspace of the wrist joint of the TULEE was analyzed, and the dexterous workspace of the wrist was analyzed by using the condition number of the Jacobian matrix. The control strategy of the TULEE was proposed based on the principle of admittance control. Finally, an experimental prototype of the TULEE was built, and the feasibility of the control strategy was verified by a servo control experiment testing a single joint and a combined control experiment testing multiple joints. Through simulated surgical experiments, it was verified that TULEE can follow the wearer’s arm movement, provide assistance for the wearer’s arm movement in the following control mode, and lock the joint rotation angle in the steady-state control mode to reduce external disturbances and reduce the risk of unsuccessful surgery.

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