Daniel G. Cole
Dept. of Mech. Eng., Virginia Polytech. Inst. and State Univ., Blacksburg, VA 24061
Robert L. Clark
Duke Univ., Durham, NC 27708-0300
An adaptive filter is used to estimate the feedthrough capacitance of a piezoelectric sensoriactuator in this work. The mechanical response of the piezostructure is resolved from the electrical response of the piezoelectric device through standard adaptive signal processing techniques. Two common adaptive algorithms are reviewed for the given application: the LMS and the RLS. For spectrally white inputs the adaptation of the digital compensator yields a filter output which is proportional to the electrical response of the piezoelectric device. Thus the remaining electrical signal consists of the charge due to the mechanical response of the piezostructure. An additional adaptive filter must be employed if a harmonic input is present since the harmonic input yields a bias term on the adaptive filter equal to the real part of the piezostructure response. Preliminary results from the theoretical analysis and numerical simulations indicate that adaptive signal processing can be employed to realize an adaptive, sensoriactuator for simultaneous strain actuation and sensing.