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.

Performance Analysis of a Hexagon Rolling Mechanism With Single Degree of Freedom

Abstract

This article presents a comprehensive performance analysis of the step-climbing and passive rolling modes of a hexagon rolling mechanism with single-degree-of-freedom, based on its structural characteristics and the constraints of centroid stability. First, a step-climbing model, incorporating motion parameters and support distance parameters, is established by leveraging the symmetrical posture movement characteristics of the hexagon rolling mechanism. Building on this foundation, the impact of each parameter on the mechanism’s step-climbing ability is thoroughly analyzed, and the maximum height achievable during step climbing is also examined. Subsequently, the existence and sufficient conditions for the hexagon rolling mechanism to achieve passive rolling are analyzed using the centroid fluctuation curve and its slope curves. The analysis results indicate that, due to its unique coupling structure design, the hexagon rolling mechanism possesses a passive rolling capability that is not available in conventional planar linkage mechanisms. Finally, the correctness of the theoretical model is validated through both simulation and prototype experiments.

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