Adaptive resonant shunted piezoelectric devices for vibration suppression

Abstract

This paper presents a new adaptation technique for R-L shunted piezoelectric patches (PZT) bonded on mechanical structures for single mode vibration suppression. For the implementation of the adaptive R-L shunt circuit, a new variable inductor circuit controlled by transistors is developed. Additionally, a new modelling method for shunted PZTs based on equivalent transformer and gyrator circuits is presented. This leads to a comprehensive model that simplifies the search for optimal shunt circuits. Furthermore, it allows simulating the system consisting of the structure, the PZT patch and a complex transistor or other non-linear shunts on standard electronic simulators like PSpice or Saber.Damping performance of R-L shunted piezoelectric devices is very sensitive to environmental factors changing the circuit's resonance frequency corresponding to the damped vibration mode. This requires fast adaptive tuning of the R-L shunted circuit, which is implemented using a new adaptation technique. The tuning direction of this adaptation law is obtained by detecting the phase shift between the velocity of the mechanical structure and the current in the shunt circuit. As the exact value of the phase for this technique is not required, one can reduce the adaptation problem to multiplication and integration of current and velocity. The performance of the presented new adaptive R-L shunt is compared with the common adaptation law based on minimizing the RMS value of the strain and then experimentally verified. The adaptive R-L shunt, which minimizes the phase-shift, can tune to the optimal parameters within seconds, but it needs an additional velocity sensor. In contrast, the R-L shunt minimizing the RMS value works without extra sensors, but needs some minutes to tune optimally. The new adaptive R-L shunt ciruit can be implemented in small analog electronic chips that allows integrating it in smart materials.

Shunt Damping Vibration Control Technology: A Review

“…Niederberger et al [123] presented an adaptation R-L shunted piezoelectric transducer to compensate variation of the natural frequency. The adaptation law was based on the phase match, shown in Figure 12a.…”

Structural Vibration Control via R-L Shunted Active Fiber Composites

“…The L-C circuit gets de-tuned (Niederberger et al, 2003) as the inherent piezoelectric capacitance changes as a function of temperature (Hanselka, 2002) and aging or for changing structure resonance frequencies.…”

“…n is the resonance frequency to be damped), the tuning parameter, v(t) the velocity on the structure where the piezoelectric patch is attached, I z (t) the current in the shunt circuit, and * denotes the time domain convolution operator. For more information the reader is referred to Niederberger et al (2003) and Niederberger (2005).…”

Optimal impedance design for piezoelectric vibration control

“…Another advantage of shunt damping is that the circuits can be fine-tuned online to compensate for any modeling errors experienced during the design process. Automatic online tuning techniques have also been presented [13].…”