reconnection with the ideal tree
play

Reconnection with the Ideal Tree A New Approach to Real-Time Search - PowerPoint PPT Presentation

Search Designing a solution The FRIT Algorithm Results Future work Reconnection with the Ideal Tree A New Approach to Real-Time Search Le on Illanes Department of Computer Science School of Engineering Pontificia Universidad Cat


  1. Search Designing a solution Agent-centered Search The FRIT Algorithm Issue: Heuristic Depressions Results Future work Heuristic learning (` a la LRTA*) 6 5 4 3 2 7 4 3 2 1 8 9 8 1 0 5 4 3 2 1 Path finding in an unknown environment (w/ free-space assumption) Le´ on Illanes Reconnection with the Ideal Tree

  2. Search Designing a solution Agent-centered Search The FRIT Algorithm Issue: Heuristic Depressions Results Future work Heuristic learning (` a la LRTA*) 6 5 4 3 2 7 4 3 2 1 8 9 1 0 10 5 4 3 2 1 Path finding in an unknown environment (w/ free-space assumption) Le´ on Illanes Reconnection with the Ideal Tree

  3. Search Designing a solution Agent-centered Search The FRIT Algorithm Issue: Heuristic Depressions Results Future work Heuristic learning (` a la LRTA*) 6 5 4 3 2 7 4 3 2 1 8 9 1 0 10 5 4 3 2 1 Path finding in an unknown environment (w/ free-space assumption) Le´ on Illanes Reconnection with the Ideal Tree

  4. Search Designing a solution Agent-centered Search The FRIT Algorithm Issue: Heuristic Depressions Results Future work How do we avoid erratic movements? More lookahead More learning Pruning states Le´ on Illanes Reconnection with the Ideal Tree

  5. Search Designing a solution Agent-centered Search The FRIT Algorithm Issue: Heuristic Depressions Results Future work How do we avoid erratic movements? More lookahead More learning Pruning states We asked ourselves: Anything simpler? Le´ on Illanes Reconnection with the Ideal Tree

  6. Search Designing a solution The FRIT Algorithm Design principles Results Future work Design principles 1 2 Le´ on Illanes Reconnection with the Ideal Tree

  7. Search Designing a solution The FRIT Algorithm Design principles Results Future work Design principles Avoid expensive computation 1 Sorting Learning 2 Le´ on Illanes Reconnection with the Ideal Tree

  8. Search Designing a solution The FRIT Algorithm Design principles Results Future work Design principles Avoid expensive computation 1 Sorting Learning Exploit the heuristic 2 Le´ on Illanes Reconnection with the Ideal Tree

  9. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work The FRIT Algorithm F ollow and R econnect with the I deal T ree Le´ on Illanes Reconnection with the Ideal Tree

  10. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work The Ideal Tree Definition (Ideal Tree) For a problem graph G with goal g and free-space assumption graph G M , we define an Ideal Tree to be any spanning tree for G M rooted at g . Le´ on Illanes Reconnection with the Ideal Tree

  11. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work The Ideal Tree Definition (Ideal Tree) For a problem graph G with goal g and free-space assumption graph G M , we define an Ideal Tree to be any spanning tree for G M rooted at g . In practice: parent ( s ) = argmin c ( s , u ) + h ( u ) u :( s , u ) ∈ E ( G M ) Le´ on Illanes Reconnection with the Ideal Tree

  12. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work The Ideal Tree Le´ on Illanes Reconnection with the Ideal Tree

  13. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work The Ideal Tree Le´ on Illanes Reconnection with the Ideal Tree

  14. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT Input : Given the free-space assumption graph G M , a goal g , and a starting node s 0 . s ← s 0 // Set the current state to s 0 while s � = g do Le´ on Illanes Reconnection with the Ideal Tree

  15. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT Input : Given the free-space assumption graph G M , a goal g , and a starting node s 0 . s ← s 0 // Set the current state to s 0 while s � = g do Observe the environment around s and remove non-existent arcs from G M . Le´ on Illanes Reconnection with the Ideal Tree

  16. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT Input : Given the free-space assumption graph G M , a goal g , and a starting node s 0 . s ← s 0 // Set the current state to s 0 while s � = g do Observe the environment around s and remove non-existent arcs from G M . if s has no parent node then Reconnect: Le´ on Illanes Reconnection with the Ideal Tree

  17. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT Input : Given the free-space assumption graph G M , a goal g , and a starting node s 0 . s ← s 0 // Set the current state to s 0 while s � = g do Observe the environment around s and remove non-existent arcs from G M . if s has no parent node then Reconnect: Follow: Le´ on Illanes Reconnection with the Ideal Tree

  18. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT Input : Given the free-space assumption graph G M , a goal g , and a starting node s 0 . s ← s 0 // Set the current state to s 0 while s � = g do Observe the environment around s and remove non-existent arcs from G M . if s has no parent node then Reconnect: Follow: s ← parent ( s ) // Move the agent to the parent of s Le´ on Illanes Reconnection with the Ideal Tree

  19. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT Input : Given the free-space assumption graph G M , a goal g , and a starting node s 0 . s ← s 0 // Set the current state to s 0 while s � = g do Observe the environment around s and remove non-existent arcs from G M . if s has no parent node then Reconnect: Locally search around s to find any state s ′ connected to g . Update the Ideal Tree to include the path from s to s ′ . Follow: s ← parent ( s ) // Move the agent to the parent of s Le´ on Illanes Reconnection with the Ideal Tree

  20. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Observe Follow Reconnect Le´ on Illanes Reconnection with the Ideal Tree

  21. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Follow Reconnect Observe Le´ on Illanes Reconnection with the Ideal Tree

  22. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Observe Reconnect Follow Le´ on Illanes Reconnection with the Ideal Tree

  23. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Follow Reconnect Observe Le´ on Illanes Reconnection with the Ideal Tree

  24. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Observe Reconnect Follow Le´ on Illanes Reconnection with the Ideal Tree

  25. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Follow Reconnect Observe Le´ on Illanes Reconnection with the Ideal Tree

  26. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Observe Follow Reconnect Le´ on Illanes Reconnection with the Ideal Tree

  27. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Observe Follow Reconnect Le´ on Illanes Reconnection with the Ideal Tree

  28. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Observe Follow Reconnect Le´ on Illanes Reconnection with the Ideal Tree

  29. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Observe Follow Reconnect Le´ on Illanes Reconnection with the Ideal Tree

  30. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Observe Follow Reconnect Le´ on Illanes Reconnection with the Ideal Tree

  31. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Observe Follow Reconnect Le´ on Illanes Reconnection with the Ideal Tree

  32. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work FRIT by example Observe Reconnect Follow Le´ on Illanes Reconnection with the Ideal Tree

  33. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  34. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  35. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  36. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  37. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  38. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  39. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  40. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  41. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  42. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  43. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  44. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  45. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  46. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  47. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  48. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  49. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  50. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work A better example Le´ on Illanes Reconnection with the Ideal Tree

  51. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work Video! Le´ on Illanes Reconnection with the Ideal Tree

  52. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work The Real-Time Property As described, FRIT is not a Real-Time Search Algorithm. We need a bound on the amount of states visited while reconnecting. Le´ on Illanes Reconnection with the Ideal Tree

  53. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work The Real-Time Property As described, FRIT is not a Real-Time Search Algorithm. We need a bound on the amount of states visited while reconnecting. What to do when the bound is surpassed? Le´ on Illanes Reconnection with the Ideal Tree

  54. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work Two approaches 1 2 Le´ on Illanes Reconnection with the Ideal Tree

  55. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work Two approaches Standard FRIT: Do nothing. . . [RIBH13, RIBH14] 1 2 Le´ on Illanes Reconnection with the Ideal Tree

  56. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work Two approaches Standard FRIT: Do nothing. . . [RIBH13, RIBH14] 1 FRIT RT : Use a Real-Time Search Algorithm for 2 Reconnection. [RIBH14] Le´ on Illanes Reconnection with the Ideal Tree

  57. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work Complexity Follow is O (1) Le´ on Illanes Reconnection with the Ideal Tree

  58. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work Complexity Follow is O (1) Reconnect can be O ( | V | ) Le´ on Illanes Reconnection with the Ideal Tree

  59. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work Complexity Follow is O (1) Reconnect can be O ( | V | ) Reconnect can be O ( | V | ). Using BFS as the local search algorithm, we check at most | V | nodes to see if they are connected to the goal. This check can be done as a recursive function with no side effects and can thus be memoized, ensuring that for each reconnection search we do at most | V | comparisons. Le´ on Illanes Reconnection with the Ideal Tree

  60. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work Complexity Follow is O (1) Reconnect can be O ( | V | ) Reconnect can be O ( | V | ). Using BFS as the local search algorithm, we check at most | V | nodes to see if they are connected to the goal. This check can be done as a recursive function with no side effects and can thus be memoized, ensuring that for each reconnection search we do at most | V | comparisons. Additionally, we prove correcteness and completeness for both FRIT and FRIT RT , while giving an explicit upper bound of ( | V | +1) 2 4 moves for FRIT and O ( | V | 3 ) moves for FRIT RT . Le´ on Illanes Reconnection with the Ideal Tree

  61. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work Convergence FRIT immediately converges to a suboptimal solution Le´ on Illanes Reconnection with the Ideal Tree

  62. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work Convergence FRIT immediately converges to a suboptimal solution Le´ on Illanes Reconnection with the Ideal Tree

  63. Search The Ideal Tree Designing a solution Follow and Reconnect The FRIT Algorithm FRIT and Real-Time Search Results Properties Future work Convergence FRIT immediately converges to a suboptimal solution Le´ on Illanes Reconnection with the Ideal Tree

  64. Search Designing a solution FRIT RT The FRIT Algorithm FRIT with BFS Results Comparison between approaches Future work Games: FRIT RT halves daRTAA*’s solutions 10000000 FRIT_rt(RTAA) FRIT_rt(daRTAA) Average Solution Cost (log-scale) RTAA 1000000 daRTAA 100000 10000 1000 0 20 40 60 80 100 120 140 Average time per planning episode (us) Le´ on Illanes Reconnection with the Ideal Tree

  65. Search Designing a solution FRIT RT The FRIT Algorithm FRIT with BFS Results Comparison between approaches Future work Mazes: Similar tendencies 10000000 FRIT_rt(RTAA) FRIT_rt(daRTAA) Average Solution Cost (log-scale) RTAA 1000000 daRTAA 100000 10000 1000 0 20 40 60 80 100 120 Average time per planning episode (us) Le´ on Illanes Reconnection with the Ideal Tree

  66. Search Designing a solution FRIT RT The FRIT Algorithm FRIT with BFS Results Comparison between approaches Future work Games: FRIT dominates for very small t 10000000 FRIT(BFS) Average Solution Length (log-scale) RA* AA* 1000000 100000 10000 1000 0 100 200 300 400 500 600 Average time per planning episode (us) Le´ on Illanes Reconnection with the Ideal Tree

  67. Search Designing a solution FRIT RT The FRIT Algorithm FRIT with BFS Results Comparison between approaches Future work Mazes: Again, similar tendencies 10000000 FRIT(BFS) Average Solution Length (log-scale) RA* AA* 1000000 100000 10000 1000 0 100 200 300 400 500 600 Average time per planning episode (us) Le´ on Illanes Reconnection with the Ideal Tree

  68. Search Designing a solution FRIT RT The FRIT Algorithm FRIT with BFS Results Comparison between approaches Future work FRIT(BFS) obtains better solutions 10000000 FRIT_rt(daRTAA) Average Solution Length (log-scale) FRIT(BFS) 1000000 100000 10000 1000 0 10 20 30 40 50 60 Average time per planning episode (us) Le´ on Illanes Reconnection with the Ideal Tree

  69. Search Designing a solution The FRIT Algorithm Results Future work Future work Other applications Optimizing for pathfinding in grids [RIB14] Moving-target search Dense graphs (e.g.: Airport networks) Le´ on Illanes Reconnection with the Ideal Tree

Download Presentation
Download Policy: The content available on the website is offered to you 'AS IS' for your personal information and use only. It cannot be commercialized, licensed, or distributed on other websites without prior consent from the author. To download a presentation, simply click this link. If you encounter any difficulties during the download process, it's possible that the publisher has removed the file from their server.

Recommend


More recommend