Traversability Index: A New Concept for Planetary Rovers

Daversability Index is introduced in this paper as a new and simple measure for traversabilaty of planetary surfaces by mobile robots. This index is developed using the framework of fuzzy logic, and is expressed by linguistic fuzzy sets that quantify the suitability of the terrain for traverse based on its physical properties, such as slope and roughness. The Ilt.aversability Index is used for classifysng planetary surfaces, and provides a simple means for incorporating the terrain quality data (out to about 30 meters) in the rover navigation strategy. A set of fuzzy navigation rules is developed using the Zhversability Index to guide the rover toward the safest and the most traversable terrain. In addition, another set of fuzzy rules is developed to drive the rover from its initial position and orientation to a user-specified goal configuration. These two rule sets are antegrated in a two-layer architectut-e for autonomous rover navigation without a priori knowledge about the environment. A computer simulation study is presented to demonstrate the capability of the rover to reach the goal safely while avoiding impassable terrains.