Method and apparatus for controlling magnitude and frequency of
vibrotactile sensations for haptic feedback devices. A haptic feedback
device, such as a gamepad controller, mouse, remote control, etc.,
includes a housing, an actuator coupled to the housing, and a mass. In
some embodiments, the mass can be oscillated by the actuator and a
coupling between the actuator and the mass or between the mass and the
housing has a variable compliance. Varying the compliance allows
vibrotactile sensations having different magnitudes for a given drive
signal to be output. In other embodiments, the actuator is a rotary
actuator and the mass is an eccentric mass rotatable by the actuator
about an axis of rotation. The eccentric mass has an eccentricity that
can be varied relative to the axis of rotation while the mass is
rotating. Varying the eccentricity allows vibrotactile sensations having
different magnitudes for a given drive signal.