Vacuum Compatible Percussive Dynamic Cone Penetrometer, Phase I

Honeybee Robotics proposes to develop a vacuum compatible percussive dynamic cone penetrometer (PDCP), for establishing soil bin characteristics, with the ultimate intent of taking it to a flight system level. Penetrometers are used to determine the Cone index (CI), which is a composite index influenced by both soil compressibility and shear strength. A dynamic cone penetrometer is used to estimate bearing strength, soil compressibility, and shear strength (when compared with calibration data), consisting of a percussive actuator and a rod with a sharp 60 degree cone at the end. The penetrometer is driven into the soil under constant load and the penetration, converted to California Bearing Ratio (CBR), which gives an indication of soil trafficability. The Honeybee-developed percussive dynamic cone penetrometer offers the significant advantage of being a low mass, low power, low force, stand alone device that requires limited to no human intervention to operate, as opposed to heavy and cumbersome manual Dynamic Cone Penetrometer (DCP) widely used today. This percussive system is also of further advantage with its capability to reach much greater depths than typical surface tools such as Bevameter. The high-frequency vibration of the percussive rod also reduces the force required for pushing a rod into regolith by almost two orders of magnitude. This translates directly into smaller rover/lander or less effort on behalf of an Astronaut. More »