Stereo vision and rover navigation software for planetary exploration

TLDR

NASA’s 2004 Mars Exploration Rover missions will deploy twin rovers that must autonomously navigate hazardous terrain using passive stereo vision, but limited radiation‑hardened processor power restricts their operational range. The paper outlines the rover vision and navigation systems and provides baseline timing data, aiming to assess computational requirements and explore performance gains from commercial processors. Timing measurements were obtained from prototype rover hardware, a RAD6000 platform, and commercial Pentium III and Sparc processors, with vectorized MMX operations used to accelerate stereo vision. Baseline timing results show that commercial processors, especially with MMX vectorization, can significantly speed up stereo vision, and radiation analysis indicates they are likely suitable for Mars missions.

Abstract

NASA's Mars Exploration Rover (MER) missions will land twin rovers on the surface of Mars in 2004. These rovers will have the ability to navigate safely through unknown and potentially hazardous terrain, using autonomous passive stereo vision to detect potential terrain hazards before driving into them. Unfortunately, the computational power of currently available radiation hardened processors limits the amount of distance (and therefore science) that can be safely achieved by any rover in a given time frame. We present overviews of our current rover vision and navigation systems, to provide context for the types of computation that are required to navigate safely. We also present baseline timing results that represent a lower bound in achievable performance (useful for systems engineering studies of future missions), and describe ways to improve that performance using commercial grade (as opposed to radiation hardened) processors. In particular, we document speedups to our stereo vision system that were achieved using the vectorized operations provided by Pentium MMX technology. Timing data were derived from implementations on several platforms: a prototype Mars rover with flight-like electronics (the Athena Software Development Model (SDM) rover), a RAD6000 computing platform (as will be used in the 2003 MER missions), and research platforms with commercial Pentium III and Sparc processors. Finally, we summarize the radiation effects analysis that suggests that commercial grade processors are likely to be adequate for Mars surface missions, and discuss the level of speedup that may accrue from using these instead of radiation hardened parts.