Algorithm for Locomotion Mode Selection, Energy Estimation and Path Planning for a Multi-terrain Screw-Propelled Vehicle for Arctic Exploration

The Multi-terrain Amphibious ARCtic explOrer or MAARCO is a screw-propelled vehicle designed to move seamlessly across the heterogeneous and diverse Arctic landscape. Its propulsion system consists of one or multiple pairs of helical drives (or Archimedes’ screws) that offer two modes of locomotion for straight-line motion while moving on land - Screw and Crab-crawl. In screw mode, the rover moves in a forward or backward direction by rotating the drives in opposite directions at the same speed. While in crab-crawl mode, the rover moves sideways by rotating the drives in the same direction at the same speed. This paper presents an algorithm for selecting between two modes of locomotion for straight-line motion as a function of the terrain or substrate that the rover is traversing. The algorithm is further applied for performing energy estimation and path planning. Results show that the rover chooses crab-crawl mode if the substrate fails under the stresses exerted by the rover and vice versa. The path planning section of the algorithm shows that maximizing the distance traveled in crab-crawl mode while simultaneously minimizing the distance traveled in screw mode derives the path with the least amount of required energy.