Drilling Load Model of an Inchworm Boring Robot for Lunar Subsurface Exploration

Figure 3

Structure parameters of EA and DA (, , and are the inner radius, outer radius, and middle radius of the screw flight, resp. is the screw angle. is the number of the screw flights. and are the lengths of EA and DA, resp. is the inner radius of the storage room; is the maximal height of the storage room. is the screw pitch. is the width of the screw flight).