Sun-Synchronous Robotic Exploration: Technical Description and Field Experimentation

Abstract

Sun-synchronous robotic exploration is accomplished by reasoning about sunlight: where the Sun is in the sky, where and when shadows will fall, and how much power can be obtained through various courses of action. We conducted experiments in the Canadian high arctic using a solar-powered rover to prove the concept of Sun-synchronous exploration. Using knowledge of orbital mechanics, local terrain, and locomotion power, the rover Hyperion planned Sun-synchronous routes to visit designated sites while obtaining the necessary solar power for continuous operation. Hyperion executed its plan, beginning and ending each 24-h period with batteries fully charged, after traveling two circuits of more than 6 km in barren, Mars-like terrain. The objective of the Sun-Synchronous Navigation project (http://www.frc.ri.cmu.edu/sunsync) was to create hardware and software technologies needed to realize Sun-synchronous exploration and to validate these technologies in field experimentation. In the process, we learned important technical lessons regarding rover mechanism, motion control, planning algorithms, and system architecture. In this paper we describe the concept of Sun-synchronous exploration. We overview the design of the robot Hyperion and the software system that enables it to operate in synchrony with the Sun. We then discuss results and lessons from analysis of our field experiments. This paper describes rover and planetary exploration research at Carnegie Mellon during 2000-2002.