Visual Navigation Using Sparse Optical Flow and Time-to-Transit

TL;DR

This paper introduces a biologically inspired visual navigation method for mobile robots using monocular cameras and the concept of time-to-transit, demonstrating robust control and first experimental validation of tau-based navigation.

Contribution

It presents a simple, robust theory of vision-based steering control and demonstrates its implementation in simulation and real-world experiments with a camera-equipped robot.

Findings

Tau-based steering laws enable reliable navigation.

Successful implementation in ROS-Gazebo simulations.

First experimental demonstration of tau-based visual navigation.

Abstract

Drawing inspiration from biology, we describe the way in which visual sensing with a monocular camera can provide a reliable signal for navigation of mobile robots. The work takes inspiration from a classic paper by Lee and Reddish (Nature, 1981, https://doi.org/10.1038/293293a0) in which they outline a behavioral strategy pursued by diving sea birds based on a visual cue called time-to-contact. A closely related concept of time-to-transit, tau, is defined, and it is shown that idealized steering laws based on monocular camera perceptions of tau can reliably and robustly steer a mobile vehicle within a wide variety of spaces in which features perceived to lie on walls and other objects in the environment provide adequate visual cues. The contribution of the paper is two-fold. It provides a simple theory of robust vision-based steering control. It goes on to show how the theory guides the implementation of robust visual navigation using ROS-Gazebo simulations as well as deployment and experiments with a camera-equipped Jackal robot. As far as we know, the experiments described below are the first to demonstrate visual navigation based on tau.