Static force measurement with piezoelectric sensors based on pseudorandom sequences

It is shown that the response of piezoelectric elements to pseudorandom sequences may be correlated to the external pressure the piezoelectric element is subjected to. Thus a static force sensor was developed based on this phenomenon. This is achieved by measuring the variations of the piezoelectric sensor series resonance branch (at its first resonance mode) which accurately reflects the measured force. A simple electronic interface circuit was designed to experimentally validate this new concept. Further, compared to previous piezoelectric sensors, the application of pseudorandom sequences allows for much increased rate of measurements.