EasySen to Explore Complex Swarm Navigation
EasySen, in collaboration with the University of Notre Dame’s MOSES Lab, proposes the use of radio frequency beacons to generate (switched) potential fields for navigation of large numbers of swarm agents. The idea is to use attractive beacons as waypoints and local attractors, while repelling beacons on each agent are used to control the density of agents and avoid collisions.
If a certain sequence of waypoints defines a navigation path, then the attractive beacons need to be distinguishable and need to be visited in a certain sequence. Repelling beacons are local and do not need to be distinguishable. Individual sensor swarm agents are equipped with a side-looking stereo receiver with opposite directions of highest sensitivity. A simple difference between the left and the right Receiver Signal Strength Indication (RSSI) allows to detect in which half space (relative to the center length axis of the vehicle) a beacon is located. One can then navigate towards a beacon by always moving towards the receiver side that has produced the stronger RSSI reading. For repelling beacons, one always moves towards the direction of the smaller RSSI signal.
The applications of this paradigm are many and range from environmental clean-up such as oil spill removal to surveillance and protection tasks.
Nice pictures of their current implementation, based on the mobile robots and Tmote Sky, can be seen here while a white paper can be found here. Also this video shows a ground vehicle swarm that performs a simple detection task.
