The Modal Shop, Inc.

Pcb Piezotronics, Inc.

Robert D Sill

Mark I Schiefer

Joshua B Moses

John William Hynd

James R Higbee

An improved method for calibration of dynamic motion sensors. In one aspect, the method comprises sending a low frequency driving signal to an exciter to generate a harmonic movement in a shaker table, using an optical position sensor to produce an output representative of position, computing the acceleration of the shaker table and a dynamic motion sensor under test (SUT), and comparing the output of the SUT with the instantaneous acceleration of the shaker table at different frequencies sufficient to define the performance characteristics of the SUT within a selected frequency range, among other things. In another aspect, the method comprises calibration of a dynamic motion SUT by simultaneous direct measurement of position and time. In another aspect, the optical position sensor has an electrical output representative of position for attaining a desired degree of positional accuracy.

Method for calibration of dynamic motion sensors

The invention disclosed includes a method for determining the magnitude and phase calibration of dynamic motion sensors (SUTs), such as accelerometers, velocimeters, and dynamically responding displacement transducers at low vibration frequencies, using an optical encoder as the reference. To calibrate the sensitivity, the dynamic motion sensor is mounted to a shaker mechanism which imparts harmonic linear motion in the axis of the sensitivity of the sensor. In the case of an accelerometer, the mechanism commonly includes another accelerometer as a reference sensor. However, the output of conventional reference accelerometers becomes inadequate at low frequencies. The subject of this patent is an optical encoder to measure the displacement, at frequencies at which the optical measurement is more accurate than that of an accelerometer or other dynamic motion sensor.

Reference sensor method for calibration of dynamic motion sensors

A transducer, including: a housing; a bridge sensor circuit disposed within the housing and including at least one micro electro-mechanical systems (MEMS) sensing elements and first and second output ports; circuitry disposed within the housing; and an input/output (I/O) line electrically connected to the circuitry, accessible at an exterior of the housing, and adapted for receipt of input voltage or current. The circuitry is for generating a single data signal that combines respective outputs of the first and second output ports, and transmitting the DC-coupled single data signal on the I/O line. The circuitry is for generating and transmitting to the bridge sensor circuit an excitation current or voltage using the input voltage or current.

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Laguna Hills, CA, United States of America

Robert D Sill