Characteristic automatic compensating apparatus, characteristic automatic compensating method, characteristic automatic compensating program of oscillator and positioning signal receiver

• US 7,548,130 B2
• Filed: 02/19/2004
• Issued: 06/16/2009
• Est. Priority Date: 03/17/2003
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kobayashi, Michio
• Primary Examiner(s): Chang; Joseph
• Application Number:
  US10/547,058
• Publication Number:
  US 20070035344A1
• Time in Patent Office: 1,944 Days
• Field of Search: 331/1.A, 331/176, 331/70
• US Class Current: 331/176
• CPC Class Codes: G01S 19/235 Calibration of receiver components
• CPC Class Codes: H03J 2200/11 Cellular receiver, e.g. GSM, combined with a GPS receiver
• CPC Class Codes: H03L 1/026 by using a memory for digitally storing correction values H03L1/025 takes precedence

Abstract

A characteristic automatic compensating apparatus of an oscillator includes oscillating means, temperature detecting means, characteristic determining means for measuring a drift value of an oscillating frequency while changing the temperature and for determining a coefficient of an approximated equation representing temperature and the drift value, storing means for storing the coefficient, drift value predicting means, and characteristic updating means for updating the coefficient by the measured drift value of the oscillating frequency and the temperature, wherein the characteristic determining means represents the approximated equation representing the characteristic of the temperature detected by the temperature detecting means and the drift value of the oscillating frequency of the oscillating means by a polynomial.

Claims

1. A characteristic automatic compensating apparatus of an oscillator comprising oscillating means for outputting an oscillating signal an oscillating frequency of which depends on a temperature, temperature detecting means for detecting the temperature of the oscillating means, characteristic determining means for measuring a drift value of the oscillating frequency of the oscillating means while changing the temperature and for previously determining a coefficient of an approximated equation representing a temperature frequency characteristic of the temperature detected by the temperature detecting means and the drift value of the oscillating frequency of the oscillating means, storing means for storing the coefficient of the approximated equation determined by the characteristic determining means, drift value predicting means for predicting the drift value of the oscillating frequency of the oscillating means based on the temperature detected by the temperature detecting means, and characteristic updating means for updating the coefficient of the approximated equation determined by the characteristic determining means by the measured drift value of the oscillating frequency of the oscillating means and the temperature detected by the temperature detecting means at a time point of the detection, wherein the characteristic determining means represents the approximated equation representing the characteristic of the temperature detected by the temperature detecting means and the drift value of the oscillating frequency of the oscillating means by a polynomial, and wherein the characteristic updating means updates all of the coefficients of the polynomial determined by the characteristic determining means by either one of the least squares method and the successive least squares method by dividing a temperature range at constant intervals with regard to a temperature range which is not detected by the temperature detecting means, calculating the drift value by the coefficient of the polynomial determined by the characteristic determining means for each divided temperature and forming a set of data of the temperature and the drift value, and using the provided set of the data and a set of data of the measured drift value of the oscillating frequency of the oscillating means and the temperature detected by the temperature detecting means at the time point of the detection.

2. The characteristic automatic compensating apparatus of an oscillator according to claim 1, wherein the temperature detecting means is a temperature compensating type oscillator.

3. The characteristic automatic compensating apparatus of an oscillator according to claim 1, wherein the characteristic determining means represents the approximated equation representing the characteristic of the temperature detected by the temperature detecting means and the drift value of the oscillating frequency of the oscillating means by the polynomial of a degree of 5 or more.

4. The characteristic automatic compensating apparatus of an oscillator according to claim 1, wherein the characteristic determining means represents the approximated equation representing the characteristic of the temperature detected by the temperature detecting means and the drift value of the oscillating frequency of the oscillating means by the polynomial by either of a least squares method and a successive least squares method.

5. The characteristic automatic compensating apparatus of an oscillator according to claim 1, wherein the characteristic determining means represents the approximated equation representing the characteristic of the temperature detected by the temperature detecting means and the drift value of the oscillating frequency of the oscillating means by the polynomial by a Kalman filter.

6. The characteristic automatic compensating apparatus of an oscillator according to claim 1, wherein the oscillating means includes a thermistor, a resistance value of which is changed by temperature, and a frequency thereof which is changed by temperature.

7. The characteristic automatic compensating apparatus of an oscillator according to claim 1, wherein the oscillating means is constituted by an oscillator of a gyro sensor.

8. The characteristic automatic compensating apparatus of an oscillator according to claim 7, wherein the measured drift value of the oscillating frequency of the oscillating means is measured based on a reference frequency of a global positioning system.

9. The characteristic automatic compensating apparatus of an oscillator according to claim 7, wherein the measured drift value of the oscillating frequency of the oscillating means is measured based on a carrier frequency of a base station of a portable telephone.

10. A characteristic automatic compensating apparatus of an oscillator comprising oscillating means for outputting an oscillating signal an oscillating frequency of which depends on a temperature, temperature detecting means for detecting the temperature of the oscillating means, characteristic determining means for measuring a drift value of the oscillating frequency of the oscillating means while changing the temperature and for previously determining a coefficient of an approximated equation representing a temperature frequency characteristic of the temperature detected by the temperature detecting means and the drift value of the oscillating frequency of the oscillating means, storing means for storing the coefficient of the approximated equation determined by the characteristic determining means, drift value predicting means for predicting the drift value of the oscillating frequency of the oscillating means based on the temperature detected by the temperature detecting means, and characteristic updating means for updating the coefficient of the approximated equation determined by the characteristic determining means by the measured drift value of the oscillating frequency of the oscillating means and the temperature detected by the temperature detecting means at a time point of the detection, wherein the characteristic determining means represents the approximated equation representing the characteristic of the temperature detected by the temperature detecting means and the drift value of the oscillating frequency of the oscillating means by a polynomial, and wherein the characteristic updating means updates all of the coefficients of the polynomial determined by the characteristic determining means by the Kalman filter by dividing a temperature range at constant intervals with regard to a temperature range which is not detected by the temperature detecting means, forming a set of data of the temperature and the drift value by calculating the drift value by the coefficient of the polynomial determined by the characteristic determining means for each divided temperature, and using the provided set of the data and a set of data of the measured drift value of the oscillating frequency of the oscillating means and the temperature detected by the temperature detecting means at the time point of the detection.

11. The characteristic automatic compensating apparatus of an oscillator according to claim 10, wherein the oscillating means is constituted by an oscillator of a gyro sensor.

12. The characteristic automatic compensating apparatus of an oscillator according to claim 11, wherein the measured drift value of the oscillating frequency of the oscillating means is measured based on a reference frequency of a global positioning system.

13. The characteristic automatic compensating apparatus of an oscillator according to claim 11, wherein the measured drift value of the oscillating frequency of the oscillating means is measured based on a carrier frequency of a base station of a portable telephone.

14. The characteristic automatic compensating apparatus of an oscillator according to claim 10, wherein the temperature detecting means is a temperature compensating type oscillator.

15. The characteristic automatic compensating apparatus of an oscillator according to claim 10, wherein the characteristic determining means represents the approximated equation representing the characteristic of the temperature detected by the temperature detecting means and the drift value of the oscillating frequency of the oscillating means by the polynomial of a degree of 5 or more.

16. The characteristic automatic compensating apparatus of an oscillator according to claim 10, wherein the characteristic determining means represents the approximated equation representing the characteristic of the temperature detected by the temperature detecting means and the drift value of the oscillating frequency of the oscillating means by the polynomial by either of a least squares method and a successive least squares method.

17. The characteristic automatic compensating apparatus of an oscillator according to claim 10, wherein the characteristic determining means represents the approximated equation representing the characteristic of the temperature detected by the temperature detecting means and the drift value of the oscillating frequency of the oscillating means by the polynomial by a Kalman filter.