Coyote II - Observations on Mobility Performance in distinct Terrains

Abstract :

Coyote II is a micro rover with high mobility performance in various terrains. Equipped with its own power source, on-board sensor suite and computer it is able to perform autonomous exploration tasks. The communication subsystem allows to cooperate with other systems and provides a link for remote control. Due to the robust structural design and powerful actuators, Coyote II is able to carry several kilograms ( 6 kg) of payload. A special characteristic of Coyote II is its novel locomotion concept. It combines the high mobility performance of hybrid legged-wheels (in the front) with the smooth wheel movement of spherical helical wheels (in the rear). Therefore, the scout rover is able to move on soft soil as well as on unstructured terrain and can perform side-to-side steering movements. The focus of this talk is on observations made during different test drives performed at the DFKI Space Exploration Hall in Bremen and the Airbus DS Mars Yard in Stevenage. During these tests the Space Exploration Hall was equipped with basalt split ( 0 − 1mm) while the Mars Yard was covered with 2EW ( 500,μm) quartz-based sand. Major differences in the driving performance of the rover could be observed in particular with respect to side-to-side steering movements. The rovers kinematics are introduced, providing the theoretical background for different rover manoeuvres. A comparison of the side-to-side steering movements with different parameter sets is presented by video footage. Furthermore, the results of odometry calibration for the distinct soil within the Mars Yard are presented as well as a several meter long autonomous traverse performed by Coyote II.