Latest Papers

ASME Journal of Mechanisms and Robotics

  • Mechanical Characterization of Supernumerary Robotic Tails for Human Balance Augmentation
    on August 31, 2023 at 12:00 am

    AbstractHumans are intrinsically unstable in quiet stance from a rigid body system viewpoint; however, they maintain balance, thanks to neuro-muscular sensory control properties. With increasing levels of balance related incidents in industrial and ageing populations globally each year, the development of assistive mechanisms to augment human balance is paramount. This work investigates the mechanical characteristics of kinematically dissimilar one and two degrees-of-freedom (DoF) supernumerary robotic tails for balance augmentation. Through dynamic simulations and manipulability assessments, the importance of variable coupling inertia in creating a sufficient reaction torque is highlighted. It is shown that two-DoF tails with solely revolute joints are best suited to address the balance augmentation issue. Within the two-DoF options, the characteristics of open versus closed loop tails are investigated, with the ultimate design selection requiring trade-offs between environmental workspace, biomechanical factors, and manufacturing ease to be made.

Kinematics and Force Transmission Analysis of a Decoupled Remote Center of Motion Mechanism Based on Intersecting Planes


A decoupled mechanism based on intersecting planes that can be considered as a parallel mechanism with two arms is presented in this paper. The end-effector is connected to the base through two planar serial arms. The new specific characteristics of novel mechanism allow the generation of a remote center of motion (RCM) possessing two decoupled rotational degrees-of-freedom (DoF) and a tanslational DoF. It has a simpler control scheme and a larger workspace due to the decoupling characteristics of this mechanism when compared with the RCM mechanism based on intersecting planes proposed by Li et al. This mechanism also eliminates the singularity inside its workspace that impairs the original mechanism. In the final part of this paper, through an analysis of the force transmission performance, we derive a method to adjust the length of the linkage to optimize its force transmission performance.
Read More
Journal of Mechanisms and Robotics Open Issues