**Optimal Path Planning in Time-Varying Flows with Forecasting Uncertainties**

Dhanushka Kularatne, Hadi Hajieghrary, and M. Ani Hsieh

**Abstract:** Uncertainties in flow models have to be explicitly considered for effective path planning in marine environments. In this paper, we present two methods to compute minimum expected cost policies and paths over an uncertain flow model. The first method based on a Markov Decision Process computes a minimum expected cost policy while the second graph search based method, computes a minimum expected cost path. A transition probability model is developed to compute the probability of transition from one state to another under a given action. In addition, a method to compute the expected cost of a path when it is executed in an uncertain flow field is also presented. The two methods are used to compute minimum energy paths in an ocean environment and the results are analyzed in simulations.

**Status:** To be presented at ICRA 2018 in Brisbane, Australia. Preprint to come.