Radio-Wave Based Accurate Localization for Space Rover on Small Planetary Body without Motion Information of Mother Spacecraft

Abstract

Investigations of small planetary bodies (SPBs) such as asteroids and comets have attracted increasing attention recently. In our previous research, a method to localize a space rover was proposed. This method can provide accurate localization even if the rover is located on a small planetary body (SPB). It uses a mother spacecraft as a source of radio-waves. The localization was formulated as an optimization problem to minimize a loss function defined according to estimation error, and gradient-based optimization was applied, however, this required the equation of motion of the mother spacecraft. The purpose of this paper is to introduce a method to localize a rover on an SPB that does not require motion information for the mother spacecraft. In this paper, we propose a solution based on Powell's conjugate direction method. The proposed method requires a large amount of computation. For computation reduction, a method to select the measurement data is proposed. Numerical simulations that assumed that a rover was located on an SPB were conducted along with indoor experiments to assess the proposed method of localization.

Keywords

• optimization
• localization
• rovers on a small planetary body
• powell's conjugate direction method