Multi-agent Multi-target Path Planning in Markov Decision Processes
Multi-agent Multi-target Path Planning in Markov Decision Processes
August 2020 - December 2021
August 2020 - December 2021
Inspired by autonomous vehicles operating underwater, we consider the problem of visiting a set of targets in minimum time by a team of non-communicating agents in a Markov decision process (MDP). The single-agent problem is at least NP-complete by reducing it to a Hamiltonian path problem. Even if the optimal solution to the single-agent problem is known, the multi-agent problem is NP-hard.
Inspired by autonomous vehicles operating underwater, we consider the problem of visiting a set of targets in minimum time by a team of non-communicating agents in a Markov decision process (MDP). The single-agent problem is at least NP-complete by reducing it to a Hamiltonian path problem. Even if the optimal solution to the single-agent problem is known, the multi-agent problem is NP-hard.
4 agents visiting 40 targets in a 20x20 grid-world
4 agents visiting 40 targets in a 20x20 grid-world

Key takeaways and Contributions
- An optimal algorithm for the single-agent problem based on Bellman’s optimality equation is exponential in the number of target states.
- We proposed a sub-optimal algorithm that is polynomial at each time step.
- Our algorithm generates optimal policies for certain classes of MDPs.
- We proposed a target partitioning algorithm that approximately minimizes the expected time to visit the targets for the multi-agent scenario.
- Our partitioning algorithm generates optimal partitions for clustered target scenarios.
- Our algorithms perform much faster than the optimal procedure and more optimal than the currently available heuristic on random MDPs and gridworld environments inspired by ocean dynamics.