Impact of Input Shaper Discretization on Linear Resonant Actuators for Haptic Feedback

Input shaping is an effective control technique for minimizing residual vibration in oscillatory systems with continuously-variable actuation. However, some systems can only be actuated at discrete time intervals. Such discretization can impair the effectiveness of input shaping. This paper investigates the impact of discretization on systems using input shaping control, and presents methods to mitigate detrimental effects caused by discretization. The investigation is presented in the context of controlling haptic motors called linear resonant actuators (LRAs). LRAs are frequently used in consumer electronic devices such as mobile phones.