Manual

25
3.3. Mobile beacon a.k.a. “hedgehog”
- The mobile and stationary beacons can be
easily interchanged by selecting in the
Dashboard
- The mobile beacons designed to be placed on
a robotic vehicle, copter/drone, AGV, or helmet
to trace its location. Formally speaking,
location of the mobile beacon is traced—not
the robot itself. Since the sizes and the location
of the central point of the mobile beacon and
the robot are different, the difference taken into
account in the robot’s software (SW)
- It is recommended to place the mobile beacon
horizontally to provide optimal ultrasonic
coverage in the upper hemisphere
- Its sensors must not be covered with anything that can reduce the strength of
ultrasonic signal. For example, the system won’t normally work, if one puts the
mobile beacon in a plastic box
- The beacon’s coordinates are updated according to the rate set on the Dashboard
- The system may contain one or several mobile beacons. Current implementation
relies on a time-division multiple access approach. Thus, if two mobile beacons are
activated, they share the same system bandwidth. It means that, if the 16 Hz update
rate is selected in the Dashboard and there are 2 mobile beacons in the system,
each beacon’s location will be updated with the rate of 16Hz/2 ~ 8Hz. If there are 3
mobile beacons => 16Hz/3 ~ 5Hz, etc. For 4 and more mobile beacons we
recommend using Inverse Architecture. See more in Architectures comparison
- Location data is obtained either from the “hedgehog” via USB (virtual UART), UART,
SPI, or from the modem/router via USB (virtual UART). More information on
interfaces can be found here (Mini-TX Beacons do not have pinouts, only over mirco
USB)
- Data from the beacon sent in a streaming format identical to that of GPS (NMEA
0183)
- There are 433MHz(out of production, get bug-fixing SW update only) and
868/915MHz versions available. Proprietary radio protocol is used for
communication and synchronization
- The “hedgehog” has been successfully integrated with Windows PC, Linux
machines, Raspberry Pi, Arduino boards, Intel boards, etc.
Fig.1: Super-Beacon as an example