System and method of measuring quasi-static force with a piezoelectric sensor
First Claim
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1. A quasi-static piezoelectric force sensor, comprising:
- a piezoelectric sensor;
a shunt resistor in parallel with said piezoelectric sensor, said shunt resistor having resistance several orders of magnitude smaller than that of said piezoelectric sensor and producing an analog voltage corresponding to the short-circuit current through said piezoelectric sensor;
an analog-to-digital converter (ADC) coupled to said shunt resistor so as to convert said analog voltage to a digital signal having digital values corresponding to respective instantaneous values of said analog voltage; and
a digital signal processor responsive to said ADC and configured to perform numerical integration of a digital signal derived therefrom.
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Abstract
A system and method employing a piezoelectric sensor for quasi-static force measurement substantially free of drift and with improved low-frequency response. The output signal from the sensor is sampled and integrated using digital techniques that include a drift compensation algorithm. The algorithm continually monitors the sensor output and estimates bias errors that will cause the output to drift.
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12 Claims
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1. A quasi-static piezoelectric force sensor, comprising:
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a piezoelectric sensor; a shunt resistor in parallel with said piezoelectric sensor, said shunt resistor having resistance several orders of magnitude smaller than that of said piezoelectric sensor and producing an analog voltage corresponding to the short-circuit current through said piezoelectric sensor; an analog-to-digital converter (ADC) coupled to said shunt resistor so as to convert said analog voltage to a digital signal having digital values corresponding to respective instantaneous values of said analog voltage; and a digital signal processor responsive to said ADC and configured to perform numerical integration of a digital signal derived therefrom. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A quasi-static piezoelectric force sensor, comprising:
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a piezoelectric sensor; an analog-to-digital converter (ADC) having an input coupled to said piezoelectric sensor and configured to convert an analog signal therefrom to a digital signal representative of force sensed by said piezoelectric sensor; and a digital signal processor having an input coupled to an output of said ADC and configured to perform numerical integration of a digital signal derived therefrom, said digital signal processor configured to implement a drift compensation algorithm and to produce an output signal representative of quasi-static force. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification