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.

A Novel Integrated Design Method of Parallel Mechanisms Based on Performance Requirements

Abstract

Due to the lack of connection between configuration synthesis and performance indices, many configurations obtained cannot meet the performance requirements, increasing the difficulty of configuration selection and prolonging the design cycle of the parallel mechanism (PM). In order to solve this problem, this paper proposes an inverse Jacobian matrix construction method based on performance indices. The method is realized by constructing singular values and singular vectors directly related to the performance indices. Furthermore, based on the screw expression form of the inverse Jacobian matrix, a new integrated design method that can directly meet the performance requirements is proposed. Finally, a novel ankle rehabilitation mechanism is presented using this method, and the correctness and effectiveness of the integrated design method are verified by theoretical analysis. Meanwhile, the analysis results show that the proposed method can effectively shorten PM’s design time and simplify PM’s design process, which has a good application value.

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