Dynamical model of asymmetric actuator of directional motion

We consider an oscillation-based actuator in which directed motion is generated by a spherical contact subjected to superimposed oscillations in vertical and horizontal directions. We consider the full dynamical problem with account of contact forces arising due to the superimposed periodic loading. We find that the system can have two regimes: either motion in one direction or stick–slip motion, when velocity periodically changes its sign. The actuator can also produce directed motion against an external horizontal force (modeling dragging a “cargo”).