Multi-Agent Pathfinding with Continuous Time
  Multi-Agent Pathfinding (MAPF) is the problem of finding paths for multiple
agents such that every agent reaches its goal and the agents do not collide.
Most prior work on MAPF was on grids, assumed agents' actions have uniform
duration, and that time is discretized into timesteps. We propose a MAPF
algorithm that does not rely on these assumptions, is complete, and provides
provably optimal solutions. This algorithm is based on a novel adaptation of
Safe interval path planning (SIPP), a continuous time single-agent planning
algorithm, and a modified version of Conflict-based search (CBS), a state of
the art multi-agent pathfinding algorithm. We analyze this algorithm, discuss
its pros and cons, and evaluate it experimentally on several standard
benchmarks.
