A Study of a Class of Vibration-Driven Robots: Modeling, Analysis, Control and Design of the Brushbot

Abstract

In this paper we present a study of a specific class of vibration-driven robots: the brushbots. In a bottom-up fashion, we start by deriving dynamic models of the brushes and we discuss the conditions under which these models can be employed to describe the motion of brushbots. Then, we present two designs of brushbots: a fully-actuated platform and a differential-drive-like one. The former is employed to experimentally validate both the developed theoretical models and the devised motion control algorithms. Finally, a coordinated-control algorithm is implemented on a swarm of differential-drive-like brushbots in order to demonstrate the design simplicity and robustness that can be achieved employing a vibration-based locomotion strategy.This work has been submitted to the IEEE for possible publication.

Inertial effects of self-propelled particles: From active Brownian to active Langevin motion

“…Regarding the first situation, one of the best realization of our model equations (22) for active Langevin dynamics can be found for active granulates [13][14][15][16][17][18][19][20][21][22] . Typically these are hoppers with a Janus-like body or with tilted legs.…”

“…These motions are only virtually damped. Another important realization are granulates made self-propelling on a vibrating plate [13][14][15][16][17][18][19][20][21][22] or equipped with an internal vibration motor 23 where it has been shown that the active Langevin model indeed describes their dynamics well [24][25][26] . Further examples for self-propelled particles with inertia range from mini-robots 27,28 to macroscopic swimmers like beetles flying at water interfaces 29 and whirling fruits self-propelling in air 30 .…”

Non-Uniform Robot Densities in Vibration Driven Swarms Using Phase Separation Theory

“…Equilibrium systems like these are well understood [24], thus allowing a large body of analysis to be transferred for the study of active self-propelled systems, as discussed in [16], [25], [26]. In this paper, we leverage this connection to demonstrate how a swarm of brushbots [8] with severely constrained sensing capabilities can phase separate into regions of high and low robot density.…”

“…In this paper, we highlight a mechanism to achieve coexisting regions of low and high robot density in swarms with severe constraints on sensing and communication. We demonstrate these behaviors on a team of vibration-driven robots, called brushbots [8], which achieve directed locomotion by vibrating bundles of flexible bristles. In particluar, these robots do not possess sensors to detect other robots and simply traverse the environment while colliding with other robots.…”

“…A team of brushbots provides an ideal platform for achiev-ing such variable density behaviors, since their minimalist construction makes them robust to the force experienced during inter-robot collisions even at relatively high speeds [8]. Additionally, the inherently noisy dynamics of the brushbots ensures that-similar to active matter systems-high-density robot clusters do not last infinitely long.…”