Design and Evaluation of Assistive Supernumerary Robotic Limbs for Near-ground operations in Confined Spaces

Abstract

Operations in confined spaces are prevalent in large-scale manufacturing industries. The complexity of such environments and spatial constraints often necessitate unconventional working postures, impacting operational sustainability and posing potential health risks. Conventional assistive devices are often inadequate in these settings. This paper introduces a wearable and portable assistive device, supernumerary robotic limbs (SRLs), designed to provide support without hindering the user’s natural limb function. We present the design and optimization of this novel bilateral SRL system specifically tailored for near-ground operations in confined spaces. The proposed device facilitates body weight support and active posture adjustments. By optimizing its mechanical structure, the system achieves improved torque density. Additionally, human-SRL collaborative experiments are conducted and the biomechanical analysis demonstrates that the proposed system reduces the user’s energy expenditure during near-ground tasks by up to 20%, validating the effectiveness of the proposed SRL system.