Experimental Study of Alternative Rover Configurations and Mobility Modes for Planetary Exploration

This paper reports on an experimental study to quantify the influence of the different adaptation capabilities that can be leveraged to improve the performance of low-cost four-wheeled rovers on sandy terrain. Conjointly with the ability to displace the center of mass and incline the rover's body, three configurations of passive suspensions and eight different locomotion modes are examined. The experiments are performed on sub-scale prototypes, with size, mass, and wheel geometry determined by a scaling analysis that ensures the consistency and transferability of the performance metrics to a 500 kg lunar rover equipped with 80 cm diameter wheels. The different configurations and locomotion modes are tested on GRC-1 lunar simulant on either a flat ground, a 20 degrees slope or a 30 degrees slope, while climbing uphill or downhill, with a 90 degrees or 45 degrees angle of attack. The performance metrics observed are the travel reduction, the lateral deviation and the energy consumption.