Cooperative Collision Avoidance in Mobile Robots using Dynamic Vortex Potential Fields

In this paper, the collision avoidance problem for non-holonomic robots moving at constant linear speeds in the 2-D plane is considered. The maneuvers to avoid collisions are designed using dynamic vortex potential fields (PFs) that are functions of relative velocities in polar coordinates. Introduction of vorticity in the calculation of the gradients leads to a cooperative collision avoidance behaviour between the robots and also ensures the absence of local minima. Such a repulsive field is activated by a robot only when it is on a collision path with other mobile robots or stationary obstacles. By analysing the kinematics-based engagement dynamics in polar coordinates, the PF parameters are identified that ensure collision avoidance with stationary and moving robots, as well as those actively seeking to collide with it. Experimental results acquired using a mobile robot platform that support the theoretical contributions are presented.