A Modular Robotic Mechanism for Discrete Rock Sampling on Mars
Final Year Engineering Honours Project
Recipient of the CROWN Robotics Technology Centre Industry Award
MECHENG700 | Oct 2024 | In collaboration with Rahul Bhati and supervised by Dr. Minas Liarokapis
Abstract: The collection of unique geological samples like silica sinter deposits on Mars, which are critical in the search for extraterrestrial life, is currently hindered by the absence of specialized sampling mechanisms designed with these unique rock structures in mind. Robotic systems have emerged as essential tools for exploring extraterrestrial environments as they can operate in conditions that are inhospitable or unreachable by humans, thus reducing costs and risks associated with manned space missions. In the context of Mars exploration, developing robotic systems capable of precisely collecting geological samples like silica sinters is key to advancing the search for signs of past or present life.
This report details the design, construction, and validation of a novel autonomous sampling system engineered to address this gap, offering a solution for collecting and preserving these geological features for analysis. The system features a specialized end effector capable of grasping rocks with different morphologies and varying degrees of brokenness, showcasing its versatility in handling a diverse range of samples. The design employs innovative fin-ray inspired finger structures made from polylactic acid (PLA) and thermoplastic polyurethane (TPU), each selected for their unique properties to enhance the performance of the end effector during the scooping and lifting phases of the sampling process.
Extensive validation testing revealed the end effector’s high success rate in grasping larger samples while preserving essential surface features critical for analysis. Comparative analyses demonstrated that PLA fingers excelled during the scooping phase due to their lower friction characteristics, while TPU fingers performed better with broken samples thanks to their flexibility and higher friction that minimized slippage. These findings suggest that a hybrid design, integrating the advantageous features of both materials, could further enhance grasping performance.
Future work will focus on refining the end effector design for seamless integration with the cutting tool, addressing positional error challenges, and investigating methods for stabilizing rocks during sampling. Overall, this project significantly advances the development of tools to collect silica sinter deposits on Mars, which are of great importance in the ongoing search for signs of extraterrestrial life.