Firefly Eindhoven - Localization - Ultrasound

This page discusses the Ultrasound system manufactured and distributed by Marvelmind Robotics [1]. The working principle of the system will briefly be discussed followed by a user manual on the system.

Working principle

The Ultrasound system by Marvelmind consists of small (~7cmx7cm) beacons (recognized by the 5 ultrasound transmitters on top) and a modem (~3cmx3cm). For the system to work, one should assign at least 2 (2D location estimation) or 3 (3D location estimation) beacons to be stationary. The stationary beacons function as an anchor point in the world and the positions of these beacons need to be known as accurately as possible (+- 3 cm) for good results. Mobile beacons (i.e. non-stationary beacons, also called hedge beacons) can then be triangulated given the distances to each stationary beacon and the location of these stationary beacons in the world frame. This is done by transmitting an ultrasound signal from the mobile beacon. This signal is then received by the stationary beacons, which then determine the range to the mobile beacon by an algorithm created by Marvelmind. These distances are send to the modem through radio with a predefined radio profile. The modem then triangulates the mobile beacons based on these distances.

User manual

Installation

This documentation will not focus on installing the dashboard (graphical software tool to view beacon output, change the configuration and settings) and the drivers for the modem. The instructions on how to do this can be found at [2]. The dashboard can be downloaded at [3].

Software

• Link to code repository