Stigmergic navigation on an RFID floor with a multi-robot team Ali Abdul Khaliq Maurizio Di Rocco Alessandro Saffiotti

Transcription

1 Stigmergic navigation on an RFID floor with a multi-robot team Ali Abdul Khaliq Maurizio Di Rocco Alessandro Saffiotti AASS Cognitive Robotic Systems Lab University of Örebro, Sweden 1

2 Motivation Stigmergy in nature Animals use the environment for indirect communication For example: ants (pheromone trials) 2

3 Can we exploit Stigmergy with robots? Previous work: Distance map building (Johansson and Saffiotti, ICRA 2009): Extension: Obstacle map building, coordinated exploration and safe navigation 3

4 Shortest Path to Goal Distance Map (Johansson and Saffiotti, ICRA 2009): Store a distance map in the environment Use a RFID tag reader equipped mobile robot Tag reader Euclidean distance Distance considering obstacles 4

5 Distance Map Building with multiple robots 1 5

6 Distance Map Building with multiple robots Black = Unvisited tags More green = Goal tag More red = More distant C= C= Variant of Bellman-Ford algorithm 6

7 Distance Map Building with multiple robots No need to save the states Decentralized Indirect communication Add/remove robots at anytime Visualization of experiment Real robots during experiment 7

8 Distance Map Building with multiple robots No need to save the states Decentralized Indirect communication Add/remove robots at anytime Goal tag 8

9 Distance Map Building: Convergence Stored value at time t Shortest distance 9

10 Obstacle Map Building with multiple robots 2 10

11 Obstacle Map Building with multiple robots The value at each tag of RFID floor is proportional to closeness to the nearest obstacle This map can be used for obstacle avoidance l Obstacle three tags away! 11

12 Obstacle Map Building with multiple robots The value at each tag of RFID floor is proportional to closeness to the nearest obstacle This map can be used for obstacle avoidance 12

13 Multi robot Coordination in Map Building 3 13

14 Multi robot Coordination in Map Building Exploration without coordination of robots 14

15 Multi robot Coordination in Map Building Each robot mark its own territory Territory marked by each robot 15

16 Multi robot Coordination in Map Building Each robot mark its own territory Coordinated exploration of four robots 16

17 Multi robot Coordination in Map Building Each robot mark its own territory Coordinated exploration of four robots 17

18 Safe navigation on the built maps 4 18

19 Safe navigation on the built maps Navigation on the built map towards the target position, by using a combination of the distance map and the obstacle map Minimum clearance 19

20 Safe navigation on the built maps Navigation on the built map towards the target position, by using a combination of the distance map and the obstacle map Obstacle clearance is set to two tags Obstacle clearance is set to one tag 20 Safest navigation

21 Safe navigation on the built maps Goal tag Navigation on the built map towards the target position, by using a combination of the distance map and the obstacle map Obstacle clearance is set to two tags Obstacle clearance is set to one tag 21 Safest navigation

22 Safe navigation on the built maps Goal tag Goal tag Navigation on the built map towards the target position, by using a combination of the distance map and the obstacle map Obstacle clearance is set to two tags Obstacle clearance is set to one tag 22 Safest navigation

23 Safe navigation on the built maps Goal tag Goal tag Navigation on the built map towards the target position, by using a combination of the distance map and the obstacle map Obstacle clearance is set to two tags Goal tag Obstacle clearance is set to one tag 23 Safest navigation

24 Conclusion Distance Map are Building with multiple robots Obstacle Map Building with multiple robots Multi robot Coordination in Map Building Safe navigation on the built maps Distance map Coordination Navigation Obstacle map 24

25 Next Steps We are currently performing experiments in real apartments equipped with RFID floors Including heterogeneous robots in map building and in navigation Smart exploration of environment when building the maps 25

26 Thank you! 26