Latest Papers

ASME Journal of Mechanisms and Robotics

  • Investigation on a Class of 2D Profile Amplified Stroke Dielectric Elastomer Actuators
    on September 24, 2024 at 12:00 am

    AbstractDielectric elastomer actuators (DEAs) have been widely studied in soft robotics due to their muscle-like movements. Linear DEAs are typically tensioned using compression springs with positive stiffness or weights directly attached to the flexible film of the DEA. In this paper, a novel class of 2D profile linear DEAs (butterfly- and X-shaped linear DEAs) with compact structure is introduced, which, employing negative-stiffness mechanisms, can largely increase the stroke of the actuators. Then, a dynamic model of the proposed amplified-stroke linear DEAs (ASL-DEAs) is developed and used to predict the actuator stroke. The fabrication process of linear DEAs is presented. This, using compliant joints, 3D-printed links, and dielectric elastomer, allows for rapid and affordable production. The experimental validation of the butterfly- and X-shaped linear DEAs proved capable of increasing the stroke up to 32.7% and 24.0%, respectively, compared with the conventional design employing springs and constant weights. Finally, the dynamic model is validated against the experimental data of stroke amplitude and output force; errors smaller than 10.5% for a large stroke amplitude (60% of maximum stroke) and 10.5% on the output force are observed.

Design and Analysis of a Lunar Crewed Vehicle With a Novel Versatile Compliant Suspension Mechanism

Abstract

A lunar crewed vehicle (LCV) with improved maneuverability, mobility, and ride comfort is required for astronauts to conduct long-range scientific investigations and resource utilization on the Moon’s surface. This paper concentrates on designing a novel multi-functional compliant suspension for LCV to improve the above-mentioned performance. First, based on the requirement of high-speed traversing on the rough Lunar terrain, the required type of suspension motion is identified and the demanded suspension mechanism is obtained through structural evolution. Then, the kinematic analysis of the proposed suspension mechanism is conducted, and the steering kinematic model of the whole vehicle is established. A compliance analysis is completed, taking into account the actual design characteristics of the suspension mechanism. A multi-degrees-of-freedom dynamics model of the vehicle is developed, considering both wheel–ground separation and the deformation of wheels and soil. Simulations are conducted to verify full vehicle performance with the proposed suspension, and the results reveal that the design features better mobility and comfort in rough terrain with minimum turning radius, peak longitudinal acceleration, and root mean square reduced by 9.5%, 45.1%, and 21.4%, respectively.

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