Unifying inertial and relative solutions for planetary hopper navigation

Hopping vehicles provide advantages over traditional surface exploration vehicles, such as wheeled rovers, by enabling in-situ measurements in otherwise inaccessible terrain. However, significant development over previously demonstrated vehicle navigation technologies is required to overcome the inherent challenges involved in navigating a hopping vehicle, especially in adverse terrain. This paper describes inertial and relative planetary surface navigation techniques for a propulsive planetary hopper. Draper & MIT have been working on an integrated solution for safe and precise landing and traversing via hopping. This modular sensor system uses inertial measurement units (IMUs) and vision-aided packages to analyze the tradeoffs associated with the fusion of inertial and relative sensor solutions, and to act as a proof-of-concept for a hopper navigation system incorporating unified inertial and terrain-relative navigation solutions. This navigation sensor is used to provide the basis for a discussion of the relative merits of inertial and vision-based navigation systems. In addition, a preliminary testing plan for advancing this system to mission-ready status is proposed.