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.

Uniform Stretch Behavior of Creased Units

Abstract

Compared to ideal purely rotational creases, the introduction of rotational stiffness in the creases of origami/kirigami units inevitably alters the shape transformation process due to the interaction between the creases and the panels. The unfolding process of creased units with crease rotational stiffness involves two stages: the flattening process and the over-tensioning process. This paper focuses on the impact of crease rotational stiffness on the uniform stretching process of creased units of different modes and sizes. During the flattening process, the strain energy distribution for creased units in straight and inclined modes is analyzed, revealing the influence of geometric parameters through the use of a scale parameter, which can provide references for the design of creased units. In the over-tensioning process, the suppression effect of low over-tension strain levels on out-of-plane residual deformation in the flattened state of the creased units is systematically explained, with a significant influence from panel width. Additionally, it is discovered and explained that over-tension strain can lead to the overall rotation of certain areas in inclined creased units. Although this paper starts with a simple creased unit and overlooks the interactions between panels, the coupling deformation behavior between the crease and the panels during the tensioning process can still provide valuable insights for the deformation analysis of more intricate origami/kirigami structures.

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