Position and Attitude Estimation for Distributed Exploration of Small Rovers Using Flash Light from Leader Agent

摘要

Surface exploration by the distributed robots is a countermeasure way to the solo exploration by using a large and expensive rover. The distributed rover can explore a large area at the same time, and it is expected to improve the exploration speed. However, the mass resource of the distributed small rover is limited. A small and lightweight position and attitude estimation system is also required for rover guidance and control. In this paper, we propose a compact, lightweight attitude and position estimation system for distributed rover using light from the leader agent. A small photodiodes are used as a sensor of a position estimation system using light for the small exploration rover. Photodiodes mounted on the follower rover in different directions detect the light from the leader to estimate the vector in the light source direction with respect to the rover body coordinate system. The attitude is decided by using the estimated light source direction vector and the gravitational vector by the acceleration sensor in the rover. After determining the attitude, the distance between the leader rover and the follower rover is estimated using the elevation angle of the light source and the light source height information. If there is communication between the leader and followers, more complicated mutual position recognition is possible, but here we discuss the limits that can be achieved with minimum hardware. We also describe the light source recognition from the leader rover under ambient light, and also discuss the overall scheme of the exploration system.