EP2047914A1 — Adaptive piezoelectric actuator control system

USPTO Abstract

Adaptive piezoelectric actuator control system for a liquid droplet spray device, comprising: power supply means (1, 2), a piezoelectric actuator, a driver (3) for driving said piezoelectric actuator so as to activate said liquid droplet spray device (8), a signal generator (7) for providing a frequency signal to said driver (3) for driving said piezoelectric actuator (8) at a frequency as defined by said frequency signal, a user interface (4) for allowing a user for inputting operating conditions of said liquid droplet spray device (8), memory means for storing internal and external parameters of said piezoelectric actuator, and system control means (5) for controlling said power supply means (2, 3), said driver (3), said signal generator (7) and said memory means (6) so that the operating frequency of said piezoelectric actuator is monitored and regulated in time such that said piezoelectric actuator operates correctly while consuming as little power as possible, wherein said driver (3) comprises test signal means for providing a test signal to said piezoelectric actuator, said test signal being provided by said signal generator (7), voltage measurement means for measuring a voltage applied to said piezoelectric actuator caused by said test signal, and for measuring a voltage applied to said piezoelectric actuator caused by said frequency signal, said system control means (5) receiving a response signal in response to said test signal, and receiving said voltages measured by said voltage measurement means, and comprising signal analysis means for creating an envelope of said response signal and controlling said signal generator to generate a frequency signal corresponding to the maximum of said envelope.