DEVICE FOR MEASURING A POSITION OF A MOBILE STATION

• US 20100048140A1
• Filed: 11/13/2007
• Published: 02/25/2010
• Est. Priority Date: 11/20/2006
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ueda, Akihiro, Tajima, Yasuhiro, Nagamiya, Kiyomi, Nakamura, Mitsuru, Hasegawa, Naoto, Shibata, Naoto
• Granted Patent: US 8,035,554 B2
• Time in Patent Office: Days
• US Class Current: 455/67.110
• CPC Class Codes: G01S 19/44 Carrier phase ambiguity resolution; Floating ambiguity; LAMBDA [Least-squares AMBiguity Decorrelation Adjustment] method
• CPC Class Codes: G01S 19/48 by combining or switching between position solutions derived from the satellite radio beacon positioning system and position solutions derived from a further system
• CPC Class Codes: G01S 5/017 Detecting state or type of motion

Abstract

A device for measuring a position of a mobile station according to the present invention comprises: first measuring means for measuring the position of the mobile station based on observed data of signals from satellites using a one-epoch measuring method; second measuring means for measuring the position of the mobile station using previous determination result of the position of the mobile station and speed information representative of a speed of the mobile station; third measuring means for measuring the position of the mobile station using solutions of variables derived from previous determination results of the first or second measuring means; and controlling means 60 for selecting one of the respective measuring means which is to execute its measuring process; wherein if reliability of the determination result of the selected measuring means is lower than a predetermined reference value, the controlling means selects another measuring means to make it execute its measuring process.

Claims

1. A device for measuring a position of a mobile station, comprising:

first measuring means for measuring the position of the mobile station based on observed data of signals from satellites using a one-epoch measuring method;

second measuring means for measuring the position of the mobile station using a previous determination result of the position of the mobile station and speed information representative of a speed of the mobile station;

third measuring means for measuring the position of the mobile station using solutions of variables derived from previous determination results of the first or second measuring means; and

controlling means for selecting one of the respective measuring means which is to execute its measuring process;

wherein if reliability of the determination result of the selected measuring means is lower than a predetermined reference value, the controlling means selects other measuring means to make it execute its measuring process.

2. The device for measuring a position of a mobile station as claimed in claim 1, wherein the controlling means selects the second or third measuring means with higher priority than the first measuring means, when the number of observable satellites exceeds a predetermined number.

3. The device for measuring a position of a mobile station as claimed in claim 1, wherein the controlling means selects the first or third measuring means with higher priority than the second measuring means, when the measuring process of the second measuring means continues more than a predetermined time period.

4. The device for measuring a position of a mobile station as claimed in claim 1, wherein the solutions of variables are integer solutions of integer ambiguities.

5. The device for measuring a position of a mobile station as claimed in claim 4, wherein the controlling means selects the first measuring means with higher priority than other measuring means, and

wherein the controlling means is configured to operate in such a manner that

if the reliability of the determination result of the first measuring means is lower than a predetermined reference value and the integer solutions of integer ambiguities derived from previous determination results of the first or second measuring means are available, the controlling means selects the third measuring means to make it execute its measuring process;

and

if the reliability of the determination result of the first measuring means is lower than a predetermined reference value and the previous determination result of the position of the mobile station is available, the controlling means selects the second measuring means to make it execute its measuring process.

6. The device for measuring a position of a mobile station as claimed in claim 4, wherein the controlling means selects the third measuring means with higher priority than other measuring means as long as the integer solutions of integer ambiguities derived from previous determination results of the first or second measuring means are available, and

wherein the controlling means is configured to operate in such a manner that

if the reliability of the determination result of the third measuring means is lower than a predetermined reference value and the previous determination result of the position of the mobile station is available, the controlling means selects the second measuring means to make it execute its measuring process, and

if the previous determination result of the position of the mobile station is not available or if the reliability of the determination result of the third measuring means is lower than a predetermined reference value and the previous determination result of the position of the mobile station is not available, the controlling means selects the first measuring means to make it execute its measuring process.

7. The device for measuring a position of a mobile station as claimed in claim 4, wherein the controlling means selects the second measuring means with higher priority than other measuring means as long as the previous determination result of the position of the mobile station is available, and

wherein the controlling means is configured to operate in such a manner that

if reliability of the determination result of the second measuring means is lower than a predetermined reference value and the integer solutions of integer ambiguities derived from previous determination results of the first or second measuring means are available, the controlling means selects the third measuring means to make it execute its measuring process;

and

if reliability of the determination result of the second measuring means is lower than a predetermined reference value and the integer solutions of integer ambiguities derived from previous determination results of the first or second measuring means are not available, the controlling means selects the first measuring means to make it execute its measuring process.