Abstract: 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.
Type:
Grant
Filed:
September 3, 2012
Date of Patent:
November 5, 2013
Assignee:
The Modal Shop
Inventors:
Robert D Sill, Mark I Schiefer, Joshua B Moses
Abstract: 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.
Type:
Application
Filed:
September 3, 2012
Publication date:
January 10, 2013
Applicant:
THE MODAL SHOP INC.
Inventors:
Robert D. Sill, Mark I. Schiefer, Joshua B. Moses
Abstract: 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.
Type:
Grant
Filed:
November 20, 2008
Date of Patent:
October 2, 2012
Assignee:
The Modal Shop, Inc.
Inventors:
Robert D. Sill, Mark I. Schiefer, Joshua B. Moses
Abstract: 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.
Type:
Application
Filed:
November 20, 2008
Publication date:
July 16, 2009
Applicant:
The Modal Shop, Inc.
Inventors:
Robert D. Sill, Mark I. Schiefer, Joshua B. Moses