Patent ID: 9513709
Filing Date: 2016-12-06
CPC Classification: G01H,G06F,G09G,H02N

Claim Text:
1. A method of generating a haptic effect comprising: continuously generating a haptic effect signal that comprises a plurality of drive cycles that occur consecutively at a fixed time duration, wherein each drive cycle is formed of a drive period when a drive pulse is active and a monitoring period when the drive pulse is inactive; applying the haptic effect signal as an input signal to a Linear Resonant Actuator (LRA) and, while applying, determining a measured LRA vibration amplitude based on a derivative of a speed of a mass during the monitoring period of the applied haptic effect signal; comparing the measured LRA vibration amplitude to a desired amplitude; when the desired amplitude is greater than the measured LRA vibration amplitude, sending an in phase drive pulse to the LRA during a next drive period when generating and applying the haptic effect signal, wherein the in phase drive pulse is sized to cancel the difference between the measured LRA vibration amplitude and the desired amplitude; and when the desired amplitude is not greater than the measured LRA vibration amplitude, sending an out of phase drive pulse to the LRA during the next drive period when generating and applying the haptic effect signal, wherein the out of phase drive pulse is sized to cancel the difference between the measured LRA vibration amplitude and the desired amplitude; wherein the applying the haptic effect signal to the LRA generates the haptic effect.