Mobility Feasibility Study of Fuel Cell

Small hopping robots have been proposed that offer the potential to greatly increase the reach of unmanned space exploration. Using hopping, bouncing, and rolling, a small spherical robot could access and explore subterranean areas, such as craters and caves, on distant planets. Hopping mobility allows the robot to overcome larger obstacles than conventional wheeled rovers. Bouncing and rolling allows the robot to infiltrate underground areas too challenging and dangerous for manned exploration. The robots would use onboard sensors to explore and search for signs of water, biological material, and other items of interest to scientists. This thesis studies the power and mobility feasibility of the Microbot hopping robot concept. One of the most important mobility issues for autonomous robots is the availability of energy and how that energy is used. The Microbot utilizes a hydrogen fuel cell power system. A fuel cell power system design is proposed and an experimental prototype device was constructed and tested. The results presented indicate that a miniature hydrogen fuel cell power system is a feasible energy generation option for the Microbot system concept. The feasibility of the hopping mobility system is also investigated. An integrated power consumption model of the Microbot is proposed and the ability of the Microbot power and mobility systems to complete a Martian reference mission is demonstrated. Simulated studies of the mobility system's capacity to overcome obstacles and navigate the Martian terrain are presented. The results of these simulations are analyzed and the mobility and power system design tradeoffs are examined. Finally, recommendations for future research are made. Thesis Supervisor: Steven Dubowsky Title: Professor of Mechanical Engineering