Carrier phase GPS positioning device and method

• US 7,498,980 B2
• Filed: 12/02/2004
• Issued: 03/03/2009
• Est. Priority Date: 12/02/2003
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kagawa, Kazunori, Yamashita, Masashi, Onome, Hirohisa, Tajima, Yasuhiro
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): LIU, HARRY K
• Application Number:
  US10/574,218
• Publication Number:
  US 20070057839A1
• Time in Patent Office: 1,552 Days
• Field of Search: 342/357.04, 342/357.06, 701/216
• US Class Current: 342/357.27
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/44 Carrier phase ambiguity resolution; Floating ambiguity; LAMBDA [Least-squares AMBiguity Decorrelation Adjustment] method
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type

Abstract

A carrier phase GPS positioning device is disclosed, which acquires a carrier phase accumulation value of satellite signals at one time on the mobile station side, associates plural carrier phase accumulation values on the reference station side at plural times prior to the one time with the carrier phase accumulation value on the mobile station side, and estimates an integer ambiguity included in the carrier phase accumulation value of signals transmitted from the satellite received by the mobile station.

Claims

1. A carrier phase GPS positioning device, comprising:

a first integer ambiguity estimation unit that combines a plurality of first carrier phase accumulation data in a first duration extracted from data received from a satellite by a reference station at a fixed position, with one or more second carrier phase accumulation data received from the satellite by a mobile station in a second duration shorter than the first duration, and estimates an integer ambiguity included in the second carrier phase accumulation data; and

a positioning unit that determines the position of the mobile station using the integer ambiguity estimated by the first integer ambiguity estimation unit;

a movement quantity detection unit that detects a movement of the mobile station and a movement quantity of the mobile station when the mobile station is moving;

wherein the mobile station is a vehicle having wheels;

wherein the movement quantity detection unit detects a movement of the vehicle based on a wheel speed sensor that detects a rotational speed of the wheels; and

wherein when a slip ratio greater than a predetermined value is detected by at least the wheel speed sensor, the integer ambiguity estimation processing by a second integer ambiguity estimation unit is initialized, and the positioning unit determines the position of the mobile station using an integer ambiguity estimated by the first integer ambiguity estimation unit until the second integer ambiguity estimation unit estimates or re-estimates the integer ambiguity.

2. The carrier phase GPS positioning device as claimed in claim 1, wherein abnormal values are excluded from the first carrier phase accumulation data.

3. The carrier phase GPS positioning device as claimed in claim 1, wherein when reception of an electromagnetic wave emitted from the satellite is temporarily interrupted, data prior to the interruption is excluded from the first carrier phase accumulation data.

4. The carrier phase GPS positioning device as claimed in claim 1, wherein

the plurality of first carrier phase accumulation data in the first duration includes a plurality of carrier phase accumulation data transmitted from the satellite at a first number of times in the first duration;

and

the second carrier phase accumulation data in the second duration include a plurality of carrier phase accumulation data transmitted from the satellite at a second number of times in the second duration, said second number being less than the first number.

5. The carrier phase GPS positioning device as claimed in claim 4, wherein the second number equals one.

6. The carrier phase GPS positioning device as claimed in claim 3, wherein after the first integer ambiguity estimation unit estimates the integer ambiguity, the positioning unit determines the position of the mobile station using data measured on the mobile station side alone.

7. The carrier phase GPS positioning device as claimed in claim 4, wherein

the second integer ambiguity estimation unit estimates, when the mobile station is at rest, the integer ambiguity included in the second carrier phase accumulation data, said estimation being made based on the first carrier phase accumulation data and the second carrier phase accumulation data in the period when the mobile station is at rest;

and

a third integer ambiguity estimation unit estimates, while the mobile station is moving, the integer ambiguity included in the second carrier phase accumulation data while taking movement quantity detection results into consideration.

8. The carrier phase GPS positioning device as claimed in claim 7, wherein

after the second integer ambiguity estimation unit or the third integer ambiguity estimation unit estimates the integer ambiguity, the positioning unit determines the position of the mobile station using the integer ambiguity estimated by the second integer ambiguity estimation unit or the third integer ambiguity estimation unit instead of the integer ambiguity estimated by the first integer ambiguity estimation unit.

10. The carrier phase GPS positioning device as claimed in claim 1, wherein

when a plurality of reference stations is present in a communication region, the reference station is selected which is able to communicate with more satellites in common with the satellite communicating with the mobile station, and

the first carrier phase accumulation data related to the selected reference station is used.

11. The carrier phase GPS positioning device as claimed in claim 10, wherein when there are plural of the reference stations able to communicate with the same number of the satellites, the reference station is selected which has the highest minimum reception strength of signals from the satellites.

12. The carrier phase GPS positioning device as claimed in claim 1, wherein

when a plurality of reference stations, which receive signals from a plurality of common satellites and the signal reception strength with each of the common satellites exceeds a predetermined value, are present in a communication region, the reference station is selected which is closest to the mobile station, and

the first carrier phase accumulation data related to the selected reference station is used.

9. A carrier phase GPS positioning device comprising:

a first integer ambiguity estimation unit that combines a plurality of first carrier phase accumulation data in a first duration extracted from data received from a satellite by a reference station at a fixed position, with one or more second carrier phase accumulation data received from the satellite by a mobile station in a second duration shorter than the first duration, and estimates an integer ambiguity included in the second carrier phase accumulation data; and

a positioning unit that determines the position of the mobile station using the integer ambiguity estimated by the first integer ambiguity estimation unit;

a movement quantity detection unit that detects a movement of the mobile station and a movement quantity of the mobile station when the mobile station is moving;

a second integer ambiguity estimation unit that, when the mobile station is at rest, estimates the integer ambiguity included in the second carrier phase accumulation data, said estimation being made based on the first carrier phase accumulation data and the second carrier phase accumulation data in the period when the mobile station is at rest; and

a third integer ambiguity estimation unit that, while the mobile station is moving, estimates the integer ambiguity included in the second carrier phase accumulation data while taking movement quantity detection results into consideration;

wherein the plurality of first carrier phase accumulation data in the first duration includes a plurality of carrier phase accumulation data transmitted from the satellite at a first number of times in the first duration; and

the second carrier phase accumulation data in the second duration include a plurality of carrier phase accumulation data transmitted from the satellite at a second number of times in the second duration, said second number being less than the first number;

the mobile station is a vehicle having wheels;

the movement quantity detection unit detects a movement of the vehicle based on a wheel speed sensor that detects a rotational speed of the wheels; and

when a slip ratio greater than a predetermined value is detected by at least the wheel speed sensor, the integer ambiguity estimation processing by the third integer ambiguity estimation unit is initialized, and the positioning unit determines the position of the mobile station using the integer ambiguity estimated by the first integer ambiguity estimation unit until the third integer ambiguity estimation unit estimates or re-estimates the integer ambiguity.

13. A carrier phase GPS positioning method, comprising the steps of:

combining a plurality of first carrier phase accumulation data in a first duration extracted from data received from a satellite by a reference station at a fixed position, with one or more second carrier phase accumulation data received from the satellite by a mobile station in a second duration shorter than the first duration, and estimating an integer ambiguity included in the second carrier phase accumulation data; and

determining the position of the mobile station using the estimated integer ambiguity;

wherein the mobile station is a vehicle having wheels;

a movement quantity detection unit detects a movement of the vehicle based on a wheel speed sensor that detects a rotational speed of the wheels; and

when a slip ratio greater than a predetermined value is detected by at least the wheel speed sensor, an integer ambiguity is processed, and a position of the mobile station is determined using the estimated integer ambiguity.

14. A carrier phase GPS positioning method, comprising the steps of:

acquiring a carrier phase accumulation value at one time on the mobile station side;

acquiring a plurality of carrier phase accumulation values at a plurality of times prior to the one time on the reference station side;

combining the carrier phase accumulation values on the reference station side at the plural times, with a carrier phase accumulation value on the mobile station side at the one time, and estimating an integer ambiguity included in the carrier phase accumulation value of signals transmitted from the satellite received by the mobile station, the plurality of first carrier phase accumulation data in the first duration including a plurality of carrier phase accumulation data transmitted from the satellite at a first number of times in the first distance, the second phase accumulation data in the second duration including a plurality of carrier phase accumulation data transmitted from the satellite at a second number of time in the second duration, said second number being less than the first number;

estimating the integer ambiguity included in the second carrier phase accumulation data and the second carrier phase accumulation date in a second integer ambiguity estimation unit when the mobile station is at rest, and

estimating the integer ambiguity included in the second phase accumulation data in a third ambiguity estimation unit while the mobile station is moving, while taking movement quantity detection results into consideration;

wherein the mobile station is a vehicle having wheels, and the movement quantity detection unit detects a movement of the vehicle based on a wheel speed sensor detection a rotational speed of the wheels.