Turtlebot2 mobile node
Mobile node architecture description
IoT-LAB testbed offers some mobile nodes. They move on the ground in the space that contains the fixed nodes. The user interaction with the mobile open-node is similar to that of a fixed node. The use of a mobile node is explained in the tutorial Submit an experiment with a mobile M3 nodes using the web portal.
This page gives additional information on the architecture of a mobile node and provides some details on the use on each site (Strasbourg, Lille, Grenoble).
A mobile node is constituted by:
- a Turtlebot2 - a mobile robot with a notebook and a kinect.
- a complete IoT-LAB node - an open-node and gateway.
The notebook communicates with the IoT-LAB infrastructure through a dedicated wifi link and it controls the physical robot using ROS. The IoT-LAB node is carried around by the robot and is accessible like a fixed node through the REST API.
Mobile node behaviour
The behaviour of the mobile node is predefined. The mobile node can be booked only if it is docked, and it un-docks as soon as it is booked. When booked, the mobile node moves along a predefined circuit trajectory, as chosen on the configuration panel. The circuit is repeated as many times as needed to cover the duration of the experiment.
During its motion, the mobile node can avoid obstacles autonomously. When the experimentation is terminated, the mobile node goes back to the docking station. The docking station allows the mobile node to charge and run continuously on the platform.
In order to ensure the robot safety, the mobile node can not be booked if its battery is not sufficiently charged (under 70% of the full charge). During the experimentation, the mobile can interrupt its course to join the docking station to reload its battery (under 30% of the full charge).
The mobile node behaviour is illustrated below by a state-chart.
To be implemented
Predefined trajectories on each site
Currently there is only one mobile node per site, it is planned to add more mobile nodes. Configuration for mobile nodes in Grenoble, Lille and Strasbourg are different. Each site provides complementary testbed with different node types, topologies and environments. Each mobile has a dedicated docking station and various predefined circuit trajectories. The 2D information trajectories are detailed below.
In Grenoble, two mobile nodes
m3-382, located in corridor J, can follow seven circuits:
- Jhall_w: first half (west) of the J corridor (loop between p1 to p2)
- Jhall_e: second half (east) of the J corridor (loop between p2 to p3)
- Jhall: all the J corridor (p1 to p3)
- Fhall_n: first half (north) of the F corridor (loop between p3 to p4)
- Fhall_s: second half (south) of the F corridor (loop between p4 to p5)
- Fhall: all the F corridor (loop between p3 to p5)
- hall: all the building J,F,G corridors (loop between p1 to p7)
A movie illustrates the use of mobile node in the Grenoble corridor.