Implementation of an adaptive piezoelectric sensoriactuator

An adaptive algorithm implemented on a digital signal processor is used in conjunction with an analog multiplier circuit to compensate for the feedthrough capacitance of a piezoelectric sensoriactuator. The mechanical response of the piezoelectric sensoriactuator is resolved from the electrical response by adaptively altering the gain imposed on the electrical circuit used for compensation, For broadband, stochastic input disturbances, the feedthrough dynamic capacitance of the sensoriactuator can be identified on-line, providing a means of implementing direct-rate-feedback control in analog hardware. Rate feedback control is demonstrated on a cantilevered beam using the hybrid/adaptive circuit, The ability of the circuit to readapt to a change in capacitance is demonstrated by a simple experiment.