A multirange architecture for collision‐free off‐road robot navigation

Abstract

Abstract We present a multilayered mapping, planning, and command execution system developed and tested on the LAGR mobile robot. Key to robust performance under uncertainty is the combination of a short‐range perception system operating at high frame rate and low resolution and a long‐range, adaptive vision system operating at lower frame rate and higher resolution. The short‐range module performs local planning and obstacle avoidance with fast reaction times, whereas the long‐range module performs strategic visual planning. Probabilistic traversability labels provided by the perception modules are combined and accumulated into a robot‐centered hyperbolic‐polar map with a 200‐m effective range. Instead of using a dynamical model of the robot for short‐range planning, the system uses a large lookup table of physically possible trajectory segments recorded on the robot in a wide variety of driving conditions. Localization is performed using a combination of global positioning system, wheel odometry, inertial measurement unit, and a high‐speed, low‐complexity rotational visual odometry module. The end‐to‐end system was developed and tested on the LAGR mobile robot and was verified in independent government tests. © 2008 Wiley Periodicals, Inc.