Directional haptic feedback for a haptic feedback interface device. A
haptic feedback interface device, in communication with a host computer,
includes a housing physically contacted by a user operating the interface
device, and a plurality of actuators producing inertial forces when the
actuators are driven by control signals. Each of the actuators includes a
rotatable eccentric mass positioned offset on a rotating shaft of the
actuator, where the actuators are rotated simultaneously such that
centrifugal forces from the rotation of masses combine to output the
inertial forces substantially only along a single axis having a desired
direction approximately in a plane of rotation of the masses.