Structural Optimisation and Assist Performance Evaluation of a Flexible Hip Exoskeleton Inspired by Octopus Tentacles

Aiming to address the limitations of traditional flexible hip exoskeletons in assistive comfort and performance enhancement, this paper proposes a novel flexible hip exoskeleton design (OT Exoskeleton) inspired by the soft structure of octopus tentacles and combined with Series- Wedge-Structures, in order to enhance lower limb interaction comfort and reduce motion energy consumption. First, through qualitative analysing the force characteristics of the exoskeleton on the thigh, the advantage of the new structure on assistive comfort is clarified. Secondly, an assistive torque function is constructed and an assistive comfort quantification index is defined. With these two as the optimisation objectives, a multi-objective optimisation is performed under multiple constraints using the genetic algorithm to obtain the optimal design parameters. Finally, virtual machine simulation verification is conducted based on Adams software. The results show: Compared with traditional flexible exoskeletons with Series- Wedge-Structures, the OT Exoskeleton offers significantly improved comfort; in addition, compared with working conditions without wearing the OT Exoskeleton, it can reduce the work done in a single gait cycle of the hip joint by 37.5%. This study verifies the effectiveness of the new exoskeleton design and provides theoretical and technical references for the structural optimisation and performance improvement of flexible hip exoskeletons.