Example Applications of Piezoelectric Actuator Used in Adaptronics

7 Example Applications of Piezoelectric Actuator Used in Adaptronics 

There are many possibilities when controlling piezo actuators, which depends on the applications and the foreseen command. This section aims at covering many different applications involving a closed loop. Combining piezoelectric actuators with smart electronics can lead to numerous adaptronics applications. 

Open loop operations with high accuracy remain possible if the behaviour of the piezo actuator (hysteresis, drift effect) is well known, and if the command applied to the piezo is known [16]. Two examples have been recently investigated in active optics  

For these two applications, the command is repetitive therefore, the drift and hysteresis can be anticipated through a feed-forward correction, which remains dependant on the temperature and the voltage. A typical command including a pre-shaper sent to the piezo actuator is shown in Fig. 6.24. The command anticipates the drift effect during the plateau. The command amplitude is a function of the temperature. This approach is simple (it does not need any position sensor) but requires a calibration effort. 

To achieve vibration damping, the piezo actuator can be combined with an accelerometer [18]. A first solution consists of using a piezoelectric actuated proof mass damper (Fig. 6.25), in which the compliance of the proof mass corresponds to the piezoelectric compliance. The force provided by the piezo actuator is F = N V, where N is the force factor and V the applied voltage. This method is generally adapted to high frequency mode (e. g. 100. .. 400 Hz), as it remains difficult to build a piezo proof mass (PPM) at low frequency. 

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