In this paper, a combined impact localization and haptic feedback system based on time-reversal signal processing is presented for touch panel applications. Theoretical impulse responses are derived from a propagation model of bending waves in a thin elastic plate. On the basis of the impulse responses, the time-reversal technique is exploited to spot the impact location as well as to generate haptic feedback. The chief advantage of the time-reversal technique lies in its robustness of tackling broadband sources in a reverberant environment. Piezoelectric ceramic plates and voice-coil motors are used as sensors for localization, whereas only voice-coil motors are used as the actuator for haptic feedback. Experimental results demonstrated that the proposed system was effective in precise impact localization for a thin panel, while haptic feedback also implemented using time-reversal principle can generate an impulse at the previously touched position. The combined impact localization and haptic feedback system is capable of enhancing the sensation of man-machine interaction in real time fashion.
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