Persistent monitoring with a team of autonomous gliders using static soaring

Exploiting wind currents in the environment allows autonomous gliders to gain altitude and energy and consequently extend flight duration. This paper considers the problem of a persistent monitoring mission using multiple autonomous gliders and exploiting thermal soaring. Communications constraints and non-homogeneous teams of gliders are considered. A distributed method based on coordination variables is proposed to monitor the area in a cooperative manner by following a partitioning patrolling strategy. A distributed one-to-one coordination technique is used to manage the gliders' access to thermals according to their states and known thermal locations. Gliders perform a model-based estimation about their energy losses between thermals to estimate the optimal time to remain in a thermal to maintain persistent surveillance with minimum refresh time. Simulated test results are provided to evaluate how the proposed approach is able to extend the mission while maintaining near-optimal performance.