Self-reconfiguration for adaptive furniture

1. Self-reconfiguration for adaptive furniture Jocelyne Lotfi

2. Content • Goal of the Project • Previous work of Masoud Asadpour • Presentation of the algorithm • My contribution • Changes made • Future Work and Time Table

3. Goal of the project • Adapt an existing reconfiguration algorithm for the roombots • Improve the efficiency of this algorithm

4. Work of Masoud Asadpour • Graph representation • Signature • Distance Metric • Full Algorithm

5. 26 27 28 29 30 31 25 32 15 20 24 33 14 19 23 34 13 18 22 35 12 17 21 40 39 38 37 36 92 21 23 21 23 116 11 69 23 16 44 10 5 21 21 21 21 23 23 23 9 4 23 21 21 21 21 23 116 92 21 21 23 8 23 3 23 23 4 3 44 129 7 2 21 21 2 23 23 5 6 1 21 21 23 23 1 6 Graph representation • Each node is one robot • Each edge have a label representing how they are attached

6. Signature • How to say that two graph are the same ? => Signature feature 7 start e8 1 e1 e4 e7 2 e3 4 e2 e5 e6 3 6 5 Signature : [1 e1 2][2 e2 3][3 e3 2][1 e4 4][4 e5 5][4 e6 6][6 –e7 1][1 –e8 7]

7. 2’ 3 1’ 3’ 4’ 5’ 1 2 4 5 8 7 6 8’ 7’ 6’ Distance Metric • Next question : how far are we from the goal ? • Graph Edit Distance • Maximum Commun Sub-Graph, in practice use of an upper-bound. Final position Initial position

8. 1 2 3 4 5 6 7 8 9 10 11 12 Edit Actions • Attach and Detach • Imply robot’s servo moves not taken in consideration

9. Full algorithm queue empty I← Pop from the P-Queue Sgn(I)=Sgn(F) ? Output the solution Push I in a priority-queue Y N Compute Sgn(I), Sgn(F) Loop for Feasible actions Manual Revision I’← Apply action a to I begin Compute Sgn(I’) end Signature DB Sgn(I’) already exists? Y N P-Queue Save Sgn(I’) Push I’ in the P-Queue

10. My contribution • Adapt the algorithm for roombots • Change of labeling and adding of move actions.

11. What is roombots ?

12. Move Actions • Overall goal => having furniture • Three levels of freedom imply lots of movements • Want to get a type of “stuck” form in space

13. Move Actions • Change configuration in space => change of labelling 68 110

14. Change in the algorithm • Need of a fixed position representation of the robot • Move action = Detach action followed by Attach action => no change in the underlying theory base on graph edit distance • Same kind of graph, so reusability of signature process 1 0 3 5 2 8 4 7 9 6

15. Now • I have adapted the algorithm for roombots with Move action implemented • Need of test : • Number of action between start and end configuration found compare to minimum • Speed

16. Future Work • Improve efficiency by : • Different search approach • Stochastic method • Adaptation of the signature process for highly symmetric modules • Possible bigger structure handling

17. Time Table November => tests of the current version + change of search approched December => adaptation of the signature + big structures handling (if enough time) January => report + presentation

18. Questions ?