Science of Autonomy: Optimal Path Planning

Overview

Science of Autonomy: Optimal path planning optimizes maritime navigation by analyzing environmental factors such as ocean currents to determine time -optimal routes in the ocean. I hypothesized this wasn’t feasible given how vast the ocean and variables wer e. Using the Hamilton-Jacobi-Bellman (HJB) partial differential equation, reachability sets and fronts were calculated to find the furthest points a vessel can travel given ocean conditions. Simulations between Lisbon, Funchal, and Ponta Delgada were creat ed to explore how vessel speed, direction, and currents affect efficiency. Results showed that higher current magnitudes aid propulsion, while high-vorticity areas challenge navigation. Faster speeds reduce travel time but increase energy use, while slower speeds improve fuel efficiency by using favorable currents. This study shows the importance of adaptive path planning with real -time data to enhance navigation efficiency and safety. However, while I conducted this research in Portugal, my goal as a Pacif ic Islander was to apply this knowledge to my home island of American Samoa. In response to the lack of data in the South Pacific, I built an underwater remotely operated vehicle (ROV) using repurposed materials to collect oceanographic data. The ROV, designed to measure water quality, temperature, and salinity, provided information that I plan on integrating into the path-planning algorithms. This research project has the potential to revolutionize maritime navigation, provide more efficient routes, empowe r local communities, and advance the field of ocean science. Assessing the Impact of Invasive Cassiopea Jellyfish on Water Quality in Heʻeia Fishpond Justice Kong Kamehameha Schools Kapālama, Honolulu, HI Invasive upside -down jellyfish (Cassiopea) pose a significant threat to the Native Hawaiian mariculture system, Heʻeia Fishpond, by competing with cultivated fish species and stinging workers. This study aims to investigate the effects of invasive jellyfis h on water quality and characterize environmental conditions that may cause jellyfish stress and mortality. I hypothesized that Cassiopea jellyfish increase water turbidity in Heʻeia Fishpond, which may negatively affect phytoplankton growth, a food source for cultivated fish. To test this hypothesis, I set up three treatments in triplicate at Heʻeia Fishpond with 3 gallons of fishpond water, 1L sediment substrate, and an air bubbler: no jellyfish, one jellyfish, and three jellyfish. I measured the temperature, turbidity, dissolved oxygen, and pH of the water using a YSI sonde at 0, 1, 4, and 24-hour time points in two independent experiments. In the first experiment, turbidity was directly related to jellyfish density. However, in the second experiment, the highest density of jellyfish had lower turbidity than the negative controls; therefore, support for my hypothesis is inconclusive. Instead, two other water quality parameters showed consistent jellyfish density effects: incubations with jellyfish had sign ificantly lower pH and dissolved oxygen than negative controls despite the air bubbler. These results demonstrate that invasive Cassiopea can have ecological impacts on Heʻeia Fishpond. The outcomes of this study will provide crucial insights into how inva sive species can alter local ecosystems and may inform effective management strategies to mitigate their impacts on maintaining the health of Heʻeia Fishpond.