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 of a Novel Linkage for Electronic Parking Brake Transmission Systems

Abstract

This paper presents a novel mechanical transmission for pulling-cable electronic parking brakes (EPBs). The system is interposed between the brake electric actuator and the brake pads, and it exploits a 2DOF planar linkage to provide the requested brake force and ensure the correct vehicle standstill. This paper describes the working principles and main component of the adopted architecture, and compares it with the EPB state of the art. Thereafter, the paper focuses on the system requirements and consequent functional design. A first prototype of the presented mechanical transmission is then presented to discuss the role of a mechanical engagement within the system to ensure its proper behavior. In conclusion, the EPB drive motor assessment is discussed on the basis of a simplified drive chain dynamic model.

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