Obstacle avoidance of non-holonomic unicycle robots based on fluid mechanical modeling

This paper is concerned with obstacle avoidance of robots moving on a plane, based on a fluid mechanical principle known as the Circle Theorem. Considering the motion region as a fictitious fluid environment surrounding the obstacles, fluid streamlines are calculated which correspond to unique smooth paths that a mobile robot can follow without colliding with the obstacles. The design and analysis are initially performed assuming simple integrator dynamics for the agent, and later extended for more realistic non-holonomic unicycle dynamic agent models, with the help of proportional integral (PI) control and backstepping principles. Both point and non-point (ellipse) geometric models are considered for the agents in design and analysis. The fluid dynamics based designs developed for obstacle avoiding motion control of agents with non-holonomic unicycle dynamics are novel, and successfully tested via an extensive set of simulations. Application of the developed designs for motion control of unmanned aerial vehicles (UAVs) under the constraint of constant speed is also presented.