Optimal decentralized gait transitions for snake robots

Abstract

Snake robots are controlled by implementing gaits inspired from their biological counterparts. However, transitioning between these gaits often produces undesired oscillations which cause net movements that are difficult to predict. In this paper we present a framework for implementing gaits which will allow for smooth transitions. We also present a method to determine the optimal time for each module of the snake to switch between gaits in a decentralized fashion. This will allow for each module to participate in minimizing a cost by communicating with a set of modules in a local neighborhood. Both of these developments will help to maintain desired properties of the gaits during transition.

CPG-based control of smooth transition for body shape and locomotion speed of a snake-like robot

“…For future work, we plan to adopt the decentralized transition [6], for example, transiting the second the gait from the head to the tail order. This could be a potential way to ensure a repeatable locomotion during the gait transition process.…”

“…The drawback is lack of supporting prototype experiments and their snake-like robot only moves in 2D plane. Dorge [6] stated briefly that smooth transition may be not enough to ensure desired movement, and the principle should maintain the gait properties during transition. Their controller propagated the second gait down the snake-like robot during the gait transition process.…”

“…Inspired by Dorge's viewpoint [6], we divide that gait transition into three aspects: the change of body shape, locomotion speed and gait mode. They are mainly related to the amplitude, frequency and phase difference in sinusoidbased gait equation [12].…”

“…Smooth gait transition is one of the unsolved problems, which can cause undesired locomotion [6,7]. The reason is that the transition process requires another sinusoid wave which may have different phase, amplitude, or frequency.…”

Towards autonomous locomotion: CPG-based control of smooth 3D slithering gait transition of a snake-like robot

“…Although the locomotion control of snake-like robots has been widely investigated, many crucial problems still exist. An indispensable aspect of auton-omous locomotion, smooth gait transition, is one of the unsolved problems [6,7]. Unsmooth gait transition could cause undesired locomotion, like deflecting direction or even movement failure.…”