The disclosure relates to General Synchronized Vibration devices that provide haptic feedback to a user and improve the performance of existing vibratory devices. Different
actuator types may be employed to provide synchronized vibration, including linear rotary actuators, rotating eccentric
mass actuators including interleaved rotating
mass actuators, and rocking
mass actuators. A controller sends signals to one or more driver circuits to provide adjustment of vibration magnitude, frequency, and direction of the actuators. The
system may apply forces onto an object, and a sensor measures a feature(s) of the object. This information is provided to a vibration device controller, which can then modify the vibration waveform to improve overall
system performance. Fourier synthesis can be used to approximate arbitrarily shaped waveforms by controlling the phase and frequency of vibration actuators. These waveforms can include
asymmetry where the peak force in one direction is higher than the peak force in another direction.