Righting of Chinese Mitten Crabs (Eriocheir Sinensis) and Their Models

Abstract

Abstract. The usage of unmanned underwater vehicles for marine tasks is continuously growing and bioinspired stabilizing systems shall help them to gain and keep a stable position during work. Therefore the righting maneuver of E. sinensis has been studied. These crabs are able to perform a 180• -rotation with an angular velocity of 4.30 s −1 when falling underwater from a supine starting position. High-speed particle image velocimetry has shown, that propulsive forces with a peak of 0.021 ± 0.001 N were produced by the hind legs to initiate and stop the rotation. In a numerical multibody simulation a constant force of 0.009 N acting for 0.2 s leads to the same rotation. In order to prove this mechanism, it was implemented into a robotic system. Its mean density of 1.15 g/cm 3 deviates not more than 4% from the biological and numerical models. It can complete a 180• -turn within 1.03 ± 0.12 s with a rotational velocity of up to 4.25 s −1 .

Kinetostatic backflip strategy for self-recovery of quadruped robots with the selected rotation axis

“…Actuated wings were designed by Chen Li [26] for self-recovery, as inspired by cicada that opens its wings to push against the ground for self-recovery. Furthermore, an idea gained from Chinese mitten crabs was reported to solve the self-recovery problems [27]. A framework for generating quasi-static selfrecovery solutions for generic robots was developed by Kessens and Dotterweich [28] using Inertial Appendage Methods.…”