  Underwater gliders (UGs) have emerged as highly effective unmanned vehicles
for ocean exploration. However, their operation in dynamic and complex
underwater environments necessitates robust path-planning strategies. Previous
studies have primarily focused on global energy or time-efficient path planning
in explored environments, overlooking challenges posed by unpredictable flow
conditions and unknown obstacles in varying and dynamic areas like fjords and
near-harbor waters. This paper introduces and improves a real-time path
planning method, Multi-Point Potential Field (MPPF), tailored for UGs operating
in 3D space as they are constrained by buoyancy propulsion and internal
actuation. The proposed MPPF method addresses obstacles, flow fields, and local
minima, enhancing the efficiency and robustness of UG path planning. A low-cost
prototype, the Research Oriented Underwater Glider for Hands-on Investigative
Engineering (ROUGHIE), is utilized for validation. Through case studies and
simulations, the efficacy of the enhanced MPPF method is demonstrated,
highlighting its potential for real-world applications in underwater
exploration.
