Automated Insertion of Geophones using Light-Weight Robots

Abstract

Manual installation of seismic networks, i.e., geophones in extraterrestrial applications or in extreme environments on Earth is risky, expensive and error-prone. A more reliable alternative of inserting sensors into soil is the automatic deposition with a leight-weight robot manipulator. However, inserting a sensor into soil is a challenging task for robotic control since the soil parameters are variable and difficult to estimate. Therefore, this thesis investigates 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 estimated using the earth-moving equation and the Discrete Element Method. 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 chosen approach.