Semi-Autonomous Wheelless Robot Design for Small Celestial Body Exploration
James R. Bass, Sheena Lean R. Espiritu, Estevan A. Flores, Tyler F. Kwapniowski, Alexandre Lasalarie, Creighton K. Llopis, Erika McSheehy, Alison J. Olivas, Zhenchuan Yan, Carlie L. Zinder, Davide Conte · 2023
Research into asteroids and other celestial bodies with low-gravity environments is a recent interest in the space industry. Currently, minimal research exists in small celestial bodies (SCB) surface exploration. Project Inertia seeks to address this interest by developing a semi-autonomous robot utilizing reaction wheels as a proof-of-concept for a space vehicle capable of movement in SCB’s low-gravity, low-traction environments. The primary inspiration for Project Inertia’s robot comes from ETH Zurich’s Cubli robot and NASA JPL's Hedgehog, in which both robots use reaction wheels as their method of transportation. Project Inertia’s mobility system makes this project unique. The robot will use three reaction wheels, one for each degree of freedom, to move using the principle of conservation of momentum. The desired reaction wheel is brought to a high rotation rate and the motor is then abruptly shorted, which transfers the angular momentum of the reaction wheel to the robot’s body. This mobility system is supported by the guidance, navigation, and control system, which uses a path-finding algorithm to semi-autonomously determine the most appropriate path to a final target based on the site of obstacles. To validate the design, testing of individual components as well as testing of the integrated system in Earth’s conditions and simulated low-gravity, low-traction conditions are conducted at Embry-Riddle Aeronautical University. Preliminary component testing consists of Inertial Measurement Unit (IMU) accuracy, RPMs provided by the motors, and structural drop tests. The systems, testing procedures, and results are discussed in this document. The robot’s reaction wheel mobility system is focused on in this document to highlight the unique aspect of the robot’s design.