Pacific Lamprey Inspired Climbing

TL;DR

This paper introduces a novel lamprey-inspired climbing robot and gait that enables dynamic vertical climbing and steering on flat surfaces, supported by a reduced-order model and experimental validation.

Contribution

The work presents a new bio-inspired climbing gait and robot design, demonstrating effective vertical and lateral climbing capabilities with improved stride length over natural lampreys.

Findings

Robot achieves 4.1 cm vertical stride per step.

Climbing speed reaches 4.8 cm/s at 1.3 Hz actuation.

Robot's stride length exceeds that of natural Pacific Lamprey by 14%.

Abstract

Snakes and their bio-inspired robot counterparts have demonstrated locomotion on a wide range of terrains. However, dynamic vertical climbing is one locomotion strategy that has received little attention in the existing snake robotics literature. We demonstrate a new scansorial gait and robot inspired by the locomotion of the Pacific Lamprey. This new gait allows a robot to steer while climbing on flat, near-vertical surfaces. A reduced-order model is developed and used to explore the relationship between body actuation and vertical and lateral motions of the robot. Trident, the new wall climbing lamprey-inspired robot, demonstrates dynamic climbing on flat vertical surfaces with a peak net vertical stride displacement of 4.1 cm per step. Actuating at 1.3 Hz, Trident attains a vertical climbing speed of 4.8 cm/s (0.09 Bl/s) at specific resistance of 8.3. Trident can also traverse laterally at 9 cm/s (0.17 Bl/s). Moreover, Trident is able to make 14\% longer strides than the Pacific Lamprey when climbing vertically. The computational and experimental results demonstrate that a lamprey-inspired climbing gait coupled with appropriate attachment is a useful climbing strategy for snake robots climbing near vertical surfaces with limited push points.