Determining the axis of a surface of revolution using tactile sensing

Sparse tactile sensing can be used to determine the positions and orientations of objects if the objects are restricted to being of a particular class. Consideration is given to a simple example of exploiting class constraints: finding the axis of an unknown surface of revolution. Three tactile curvature measurements on a surface of revolution with sweeping rule in C² are shown to be sufficient for determining the axis except for certain singular configurations. Position and orientation error bounds and preliminary experimental results are presented for a capacitive tactile sensor with two contacts. Optimal angular spacing was seen to be 90° between contacts. Experiments showed that the method worked with a position error of 0.07 in. and an angle error of 7.3°