← Search

James Ju Heon Lee

5 accepted papers

2024

Multi-query TDSP for Path Planning in Time-varying Flow Fields

ICRA 2024poster

Many applications of path planning in time-varying flow fields, particularly in areas such as marine robotics and ship routing, can be modelled as instances of the time-varying shortest path (TDSP) problem. Although there are no known polynomial-time solutions to TDSP in general, our recent work has…

Cited by 0SourceScholar
2023

Efficient Optimal Planning in non-FIFO Time-Dependent Flow Fields

ICRA 2023poster

We propose an algorithm for solving the time-dependent shortest path problem in flow fields where the FIFO (first-in-first-out) assumption is violated. This problem variant is important for autonomous vehicles in the ocean, for example, that cannot arbitrarily hover in a fixed position and that are…

Cited by 11SourceScholar
2021

Hierarchical MCTS for Scalable Multi-Vessel Multi-Float Systems

ICRA 2021poster

Systems of multiple low-cost, underactuated floats combined with fully actuated surface vessels can improve the scalability and cost-effectiveness of autonomous systems for marine science and environmental monitoring. Here, we consider a coordination problem where surface vessels must drop off float…

Cited by 13SourceScholar
2021

Path Planning in Uncertain Ocean Currents using Ensemble Forecasts

ICRA 2021poster

We present a path planning framework for marine robots subject to uncertain ocean currents that exploits data from ensemble forecasting, which is a technique for current prediction used in oceanography. Ensemble forecasts represent a distribution of predicted currents as a set of flow fields that ar…

Cited by 19SourceScholar
2020

Hierarchical Planning in Time-Dependent Flow Fields for Marine Robots

ICRA 2020poster

We present an efficient approach for finding shortest paths in flow fields that vary as a sequence of flow predictions over time. This approach is applicable to motion planning for slow marine robots that are subject to dynamic ocean currents. Although the problem is NP-hard in general form, we inco…

Cited by 17SourceScholar