Short-Horizon Planning Guides Long-Horizon Planning Improving Solution Quality by Iterative Refinement 4. 5. 6. 7. Part I. Planning Building Representation from Learning Building Representation while Planning 11. 12. Part III. Representation Online Planning to Overcome Timing Uncertainties Offline Planning to Overcome Timing Uncertainties Offline Planning to Overcome Crash Faults 8. 9. 10. Part II. Execution Introduction, Preliminaries, and Background 1-3. Conclusion and Discussion 13. Dissertation Outline
graph goals solution paths without collisions optimization is intractable in various criteria [Yu+ AAAI-13, Ma+ AAAI-16, Banfi+ RA-L-17, Geft+ AAMAS-22]
by PRM [Kavraki+ 96] complete optimal incomplete suboptimal building small but promising representation for planning quality & solvability effort high low small large speed & scalability
low small large speed & scalability approach-1 [Chap. 11] learning from planning demonstrations approach-2 [Chap. 12] building representation while planning
Planning 4. 6. Part I. Planning Building Representation from Learning Building Representation while Planning 11. 12. Part III. Representation Rest of Talk: Quick Multi-Agent Path Planning discrete continuous
Planning 4. 6. Part I. Planning Building Representation from Learning Building Representation while Planning 11. 12. Part III. Representation Quick Multi-Agent Path Planning discrete continuous
agents within 50ms ensuring that all agents eventually reach their destinations https://kei18.github.io/pibt2 IJCAI-19 => AIJ-22 Priority Inheritance with Backtracking for Iterative Multi-agent Path Finding KO, Manao Machida, Xavier Defago & Yasumasa Tamura scalable sub-optimal algorithm (PIBT) to solve MAPF iteratively
all agents reach their destinations within finite timestep convenient in lifelong scenarios important note: PIBT is incomplete for MAPF unsolvable MAPF, but the theorem holds *s.t. unreached agents eventually get the highest
operator decomposition greedy version [Standley AAAI-10] EECBS CBS-based, bounded sub-optimal [Li+ AAAI-21] LNS2 large neighborhood search for MAPF [Li+ AAAI-22] PIBT Performance on one-shot MAPF 25 instances 30sec timeout on desktop PC sufficiently long timestep limit 194x194 four-connected grid sum-of-costs (normalized; min:1) runtime (sec) success rate agents not so bad not so bad blazing fast! worst: 550ms
room-64-64-8 64x64 |V|=3,232 ost003d 194x194 |V|=13,214 agents random-32-32-20 32x32 |V|=819 agents important note: PIBT is incomplete for MAPF We need one more jump! PIBT 0% success rate in 30sec
44 nodes only 4 configurations repeat one-timestep planning until termination use PIBT to guide exhaustive search initial configuration goal configuration
PIBT PIBT PIBT use other MAPF algorihtms to generate a promising configuration configurations are generated in a lazy manner by two-level search scheme exhaustive search but node generation are dramatically reduced => quick & complete MAPF
success rate in 1000sec runtime (sec) agents (x1000) 25 instances, timeout of1000 sec, on desctop PC warehouse-20-40-10-2-2, 340x164; |V|=38,756 Performance with x1000 agents perfect! blazing fast! worst: 26sec for 10,000 agents LaCAM wrong thought: “centralized algorithms are not scalable” => NO, the game is changing PIBT demo of 10,000 agents
solved instances (%) runtime (sec) comp & bounded sub-opt SC & bounded sub-opt incomp & sub-opt SC* & optimal comp & optimal Results on MAPF Benchmark [Stern+ SOCS-19] remaining: maze-128-128-1** **I do not care; it will be too optimized for the benchmark 13900 instances - 33 grid maps - random scenario - every 50 agents, up to max. (1000) tested on desktop PC 99.0% LaCAM* complete & eventually optimal! 32/33 maps: all solved in 10sec *SC: solution complete: unable to distinguish unsolvable instances
Planning 4. 6. Part I. Planning Building Representation from Learning Building Representation while Planning 11. 12. Part III. Representation Quick Multi-Agent Path Planning discrete continuous
sparse representation produced by PRM [Kavraki+ 96] complete optimal incomplete suboptimal ideal: small but promising representation for planning quality & solvability effort high low small large speed & scalability
each agent how to identify? agent-specific features + interactions between agents This is machine learning problem! supervised learning: planning demonstration as training data
speed & scalability learning from planning demonstrations CTRMs: Learning to Construct Cooperative Timed Roadmaps for Multi-agent Path Planning in Continuous Spaces KO,* Ryo Yonetani, Mai Nishimura & Asako Kanezaki representation https://omron-sinicx.github.io/ctrm AAMAS-22 *work done as an intern at OMRON SINIC X MAPF algorithm
next position goal-driven features comm. features indicator feature instance & solution occupancy cost-to-go env. info relative positions, size, speeds, etc attention Offline Training & Model Arch. [Sohn+ NeurIPS-15] CVAE [Hoshen NeurIPS-17]
[Karaman & Frazzoli, IJRR-11] square as agent-specific roadmaps grid as used in MAPF studies CTRMs 20-30 homogeneous agents corresponding to 32x32 grids Roadmap Visualization CTRMs produce small but effective roadmaps specific to each agent
P S S 20-30 homogeneous agents corresponding to 32x32 grids 100 instances solved by prioritized planning [Silver, AIIDE-05, Van Den Berg & Overmars IROS-05, etc] CTRMs achieve efficient path-planning from the end-to-end perspective Roadmap construction can be much faster. Check our latest implementation: https://github.com/omron-sinicx/jaxmapp Quantitative Results quick! denser
Continuous Spaces Are roadmaps truly used in planning process? Construct agent-wise roadmaps by SBMP (sampling-based motion planning) methods Solve MAPF on those roadmaps 1. 2. two-phase planning decoupled
case of MRMP solution: collision-free trajectories each agent has its own configuration space blackbox utility functions connect free space true false steer collide true false sample dist 0.18
DOF: 2N Point3d DOF: 3N R P 33 6 6663 Line2d DOF: 3N R P 3 0 33 6 6663 Capsule3d DOF: 6N R P 3 0 33 6 6663 Arm22 DOF: 2N Arm33 DOF: 6N R P 3 0 33 6 6663 Dubins2d DOF: 3N R P 6 33 6663 Snake2d DOF: 6N Performance of SSSP very promising quick!
low small large speed & scalability learning from planning demonstrations building representation while planning successfully breaking the trade-off again
trade-off (quality vs speed) connecting discrete & continuous spaces => promoting various types of automation develop new horizons of quick multi-agent path planning contribution: