Robotic deployment of extraterrestrial seismic networks

Abstract

Manual installation of seismic networks in extraterrestrial environments is risky, expensive and error-prone. A more reliable alternative is the automated deposition with a light-weight robot manipulator. However, inserting a spiked sensor into soil is a challenging task for a robot since the soil parameters are variable and difficult to estimate. Therefore, we investigate an approach to accurate insertion and positioning of geophones using a Cartesian impedance controller with a feed-forward force term. The feed-forward force component of the controller is either estimated using the Fundamental Earth-Moving Equation, the Discrete Element Method or empirically. For the first time, both the geological aspects of the problem as well as the aspects of robotic control are considered. Based on this consideration, the control approach is enhanced by predicting the resistance force of the soil. Experiments with the humanoid robot Rollin’ Justin inserting a geophone into three different soil samples validate the proposed method.