Reactive navigation of a nonholonomic mobile robot for autonomous sweep coverage of a surface embedded in a 3D workspace

Abstract

An under-actuated nonholonomic robot travels in a 3D workspace with a constant surge speed and is controlled by upper bounded pitching and yawing rates. The objective is to approach an unknown 2D surface embedded in the workspace and subsequently ensure its sweep coverage with following in a pre-specified close range. The robot is perceptually deficient and has access only to a certain direction (typically, vertical) in the space, its own coordinate (typically, altitude) in this direction, and the “horizontal” distance to the surface. A novel strategy is presented that achieves the navigation objective in an autonomous fashion, in particular, ensures full scan of the surface within a desired range of “altitudes”. This strategy is computationally non-demanding, is confined to the lowest control level, and generates the current control as a refiex-like reaction to the current observation. Mathematically rigorous analysis and justification of the proposed navigation approach are provided; its applicability and performance are confirmed by computer simulation tests.