A model of contact mechanism for a quartz-crystal tuning-fork tactile sensor

We investigated the contact mechanism for a quartz-crystal tuning-fork tactile sensor theoretically. On the assumption that the right half of a quartz-crystal tuning fork as an L-shaped bar, in which the bars acting as the base and the arm undergo bending vibration, we analyzed the frequency of a tuning-fork tactile sensor by considering the base of the tuning fork on the basis of Sezawa´s approximation and the torsion spring model as a joining mechanism of the base and the arm, and furthermore both lateral clamping force from acrylic resin case and Winkler´s foundation from the object in contact are applied on its base. Five kinds of metals (brass, copper, aluminum, stainless steel, and iron) were used in this contact experiment. The frequency of a quartz-crystal tuning-fork tactile sensor increased according to the ratio of Young´s modulus to density of materials and classified into two groups owing to the magnitudes of sound velocity of longitudinal wave traveling into metals when the sensor´s base got brought into contact with a surface of materials after the surface has been polished with #800 sandpaper.