Apparatuses and methodologies for vibration effects correction in oscillators

• US 10,340,921 B2
• Filed: 11/29/2016
• Issued: 07/02/2019
• Est. Priority Date: 10/18/2016
• Status: Active Grant

• Current Assignee: VT iDirect Inc. (Singapore Technologies Engineering Limited)
• Original Assignee: VT iDirect Inc. (Singapore Technologies Engineering Limited)
• Inventors: Wanner, Shannon
• Primary Examiner(s): Kinkead, Arnold M
• Application Number:
  US15/363,191
• Publication Number:
  US 20180109263A1
• Time in Patent Office: 945 Days
• Field of Search: 331175, 331116 R, 331 65, 331116 M, 331154, 331158
• CPC Class Codes: G01P 15/00 Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
• CPC Class Codes: G01P 15/03 by using non-electrical means
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: H03B 5/04 Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature
• CPC Class Codes: H03B 5/32 being a piezoelectric resonator selection of piezoelectric material H10N30/00
• CPC Class Codes: H03B 5/36 active element in amplifier being semiconductor device H03B5/323, H03B5/326 , H03B5/38 take precedence
• CPC Class Codes: H03L 1/00 Stabilisation of generator output against variations of physical values, e.g. power supply

Abstract

A method and system for vibration correction in an oscillator. The method includes sensing vibrations along one or more axes via at least one accelerometer mounted on the oscillator, determining corrective factors based on an acceleration signal received from the at least one accelerometer by referencing a look-up table; and controlling the oscillator based on at least the corrective factors.

Claims

1. A method for vibration correction in an oscillator, the method comprising:

sensing vibrations along one or more axes via at least one accelerometer mounted on the oscillator;

determining a g-sensitivity vector of the oscillator using measurements obtained using a vibration table and a spectrum analyzer;

calculating corrective factors as a function of the g-sensitivity vector;

storing the corrective factors in a look-up table;

determining particular corrective factors based on an acceleration signal received from the at least one accelerometer by referencing the corrective factors in the look-up table; and

controlling the oscillator based on at least the particular corrective factors.

2. The method of claim 1, wherein the at least one accelerometer is a 3-axis accelerometer.

3. The method of claim 1, further comprising:

using a second and a third accelerometer, wherein

the at least one accelerometer, the second accelerometer, and the third accelerometer are each mounted along an orthogonal axis to independently measure the acceleration each independent axis.

4. The method of claim 3, wherein the orthogonal axis is an x-axis, y-axis, or z-axis.

5. The method of claim 1, wherein the at least one accelerometer is manufactured using MEMS (Microelectromechanical system technology.

6. The method of claim 1, wherein the at least one accelerometer is positioned below the oscillator.

7. The method of claim 1, further comprising:

controlling the oscillator using a filter, the weight of the filter being pre-calibrated based on a frequency response of the oscillator.

8. The method of claim 7, wherein the filter is an analog filter.

9. The method of claim 7, wherein the filter is a digital filter.

10. The method of claim 1, wherein determining the g-sensitivity vector includes applying

11. The method of claim 1, further comprising:

measuring a spectral response of the oscillator along the one or more axes; and

calculating the corrective factors as a function of the g-sensitivity vector and the spectral response of the oscillator.

12. The method of claim 11 wherein the corrective factors are determined by applying

13. An oscillator circuit, comprising:

a crystal oscillator providing an RF (Radio Frequency) output;

an accelerometer mounted on the crystal oscillator for sensing vibrations and for providing an acceleration signal associated with the vibrations; and

processing circuitry configured to

determine a g-sensitivity vector of the oscillator using measurements obtained using a vibration table and a spectrum analyzer,

calculate corrective factors as a function of the g-sensitivity vector;

store the corrective factors in a look-up table;

determine particular corrective factors as a function of the acceleration signal by referencing the corrective factors in the look-up table; and

control the crystal oscillator based on at least the particular corrective factors.

14. The oscillator circuit of claim 13, wherein the corrective factors are a function of a g-sensitivity vector, and a spectral response of the crystal oscillator along the one or more axes, wherein the g-sensitivity vector and the spectral response are pre-measured.

15. The oscillator circuit of claim 13, wherein the processing circuitry is further configured to:

control the crystal oscillator using a filter, the weight of the filter being pre-calibrated based on a frequency response of the crystal oscillator.

16. The oscillator circuit of claim 15, wherein the filter is an analog filter.

17. The oscillator circuit of claim 15, wherein the filter is a digital filter.

18. A communication system, comprising:

at leak one electronic device being clocked by an oscillator circuit, wherein the oscillator circuit includes

a crystal oscillator providing an RF (Radio Frequency) output,

an accelerometer mounted on the crystal oscillator for sensing vibrations and for providing an acceleration signal associated with the vibrations, and

processing circuitry configured to

determine a g-sensitivity vector of the oscillator using measurements obtained using a vibration table and a spectrum analyzer;

calculate corrective factors as a function of the g-sensitivity vector;

store the corrective factors in a look-up table;

determine particular corrective factors as a function of the acceleration signal by referencing the corrective factors in the look-up table; and

control the crystal oscillator based on at least the particular corrective factors.