Analytical Model of Thermal Soaring: Towards Energy Efficient Path Planning for Flying Robots

摘要

Developing analytical models of efficient locomotion in biology is one of the most interesting goals in bio- inspired robotics. This paper presents a mathematical framework in order to model one of the most energy efficient locomotion types in flying animals; i.e., thermal soaring. Unlike the legged locomotion, in flying, modeling the environmental effects on animals' behaviors is very important. In doing so, we develop our model by assuming thermals as bubbles of rising air. According to pieces of real evidence, this kind of modeling is more compatible with the nature of thermal soaring. Moreover, we present a simple hybrid control strategy for obtaining the optimal path in order to maximize benefit from the updraft of air-flow. By using this control strategy, the flying robot can plan a path for traveling between thermals without flapping; i.e., energy efficient flying. So as to investigate the compatibility of presented model and controller with reality, we set their parameters based on the biological evidences. As a result, in simulations, it is observed that the generated flying behavior is comparable with the thermal soaring behavior of real birds. This observation provides a confirmation for generality and applicability of the presented approach.