Range-Only-Based Three-Dimensional Circumnavigation of Multiple Moving Targets by a Nonholonomic Mobile Robot.

A nonholonomic constant speed underactuated robot with a bounded control range travels in three dimensions. A group of targets unpredictably moves in all three dimensions. The robot measures only the distances to the targets and also has access to a certain spatial direction and its own coordinate (termed “altitude”) along it. We present a new navigation law that drives the robot to the locus of points at a prespecified root-mean-square distance from the targets and ensures dense sweep coverage of this locus within a given range of “altitudes.” This law is rigorously justified by a nonlocal convergence result supported by recommendations on controller tuning; its applicability and performance are confirmed by extensive computer simulations. [ABSTRACT FROM AUTHOR]