JPH1164479A - Gsp receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a GSP receiver which is enhanced in positioning accuracy. SOLUTION: The GSP receiver 1 comprises a pseudometric Doppler shift measuring section 12 for determining the pseudometric distance between each satellite and its own position and the Doppler shift every predetermined time from radio waves transmitted from GSP satellites, a section 13 for operating the positioning value at a predetermined time using the pseudometric distance and the Doppler shift value found at the measuring section 12, and a section 15 for estimating the positioning value at the predetermined time from the positioning value at the previous time wherein the positioning value operating section 13 finds the positioning value at the predetermined time while taking account of the estimated positioning value from the positioning value estimating section 15. An input interface section 16 fetches the final positioning value from a positioning navigation unit 3 for finding the final position value by fetching the positioning value form the positioning value operating section 13. The positioning value estimating section 15 estimates the positioning value using the final positioning value as the positioning value at the previous time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a GPS receiver for receiving a radio wave transmitted from a GPS satellite and obtaining a positioning value such as its current position.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a GPS receiver 1 has a GPS system (Global Position).
and a satellite signal acquisition / tracking unit 11, a pseudorange / Doppler shift measurement unit 12, a predetermined time positioning value calculation unit 13, a positioning value output interface unit 14, and a positioning value estimating unit 15. It becomes. The signals received by the GPS antenna 2 are distinguished by the satellite signal acquisition / tracking unit 11 for each satellite signal. A signal for each captured satellite is sent to the pseudorange / Doppler shift measuring unit 12, and from the satellite navigation message obtained from this signal, the position information and time information of each satellite, the time at which the satellite receives radio waves, and the GPS The pseudo distance and the Doppler shift between each satellite and the GPS receiver 1 are obtained from the information of the difference between the time when the receiver 1 receives the corresponding radio wave and the measured Doppler frequency. The predetermined time positioning value calculation unit 13 calculates the three-dimensional or two-dimensional position of the GPS receiving device 1 at a predetermined time, including the error of the internal clock, using the pseudorange and the Doppler shift as an unknown value and calculates the unknown value. As a method of this calculation, a nonlinear simultaneous equation which is established between the pseudorange and the Doppler shift at each predetermined time and the unknown number is obtained by a convergence calculation. In this case, the convergence operation results in the ambassador,
The error included in the time difference between the satellite and the GPS receiver and the increase in the error due to the geometrical divergence (DOP) determined by the spatial arrangement of the satellites used for the calculation,
The positioning result contains a large error.

Therefore, using a Kalman filter or the like, which is an estimation method based on probability theory, not only the measured value at a predetermined time but also the positioning value at a time before the predetermined time at which the positioning value is to be obtained and the GPS receiver 1 The positioning value is determined in consideration of the positioning value estimated from the dynamic characteristics and the like of the moving body equipped with the. In FIG. 5, the predetermined time positioning value calculation unit 1
3 and a positioning value estimating unit 15 for estimating a positioning value at a predetermined time from a positioning value at a previous time constitute a Kalman filter. The output of the predetermined time positioning value calculation unit 13 is input to the positioning value estimation unit 15, and the positioning value estimation unit 15 calculates the positioning value based on the positioning value at the previous time and the dynamic characteristics of the mobile unit equipped with the GPS receiver 1. An estimate is obtained. The predetermined time positioning value calculation unit 13 calculates the positioning value in consideration of the estimated value of the positioning value.

As described above, when the Kalman filter is used, the error is reduced and the accuracy is improved as compared with the case where the positioning value is obtained by the convergence calculation as described above.

The positioning value obtained by the GPS receiver 1 is input to the on-vehicle navigation device 3, and the on-vehicle navigation device 3 uses the positioning value to determine the final positioning value. The on-vehicle navigation device 3 uses, as an input value, a positioning value at a predetermined time output via the positioning value output interface unit 14 of the GPS receiving device 1, and uses this value and a signal from the angle / angular velocity detecting means 4. , Vehicle speed signal detecting means 5
And the signal from the map information memory 6 to calculate the most likely positioning value, store it in the internal memory, and display the position on the map displayed on the display device (not shown). is there.

[0006]

However, in the above-described GPS receiver, the positioning value calculated by using the Kalman filter cannot be used when the error included in the estimated value of the positioning value at the previous time is large. May drag the past information, thereby deteriorating the positioning result at a predetermined time.

[0007] The present invention has been made in view of the above points, and an object of the present invention is to provide a GPS receiving apparatus in which the accuracy of a positioning value is improved.

[0008]

According to the first aspect of the present invention,
A pseudo-range / Doppler shift measuring unit that calculates a pseudo-range and a Doppler shift between each satellite and its own position at a predetermined time from a radio wave transmitted from a GPS satellite;
A positioning value calculation unit that obtains a positioning value at a predetermined time using the pseudo distance and Doppler shift value obtained by the pseudo distance / Doppler shift measurement unit; and a positioning value at a predetermined time from the positioning value at the previous time. A positioning value estimating unit that calculates a positioning value at a predetermined time in consideration of the positioning value estimated by the positioning value estimating unit. A final positioning value input interface unit that takes in the final positioning value from the positioning navigation device that takes in the obtained positioning value and obtains the final positioning value, and the positioning value estimating unit converts the final positioning value to the positioning value of the previous time. The estimation is performed by using

According to a second aspect of the present invention, in the first aspect of the present invention, switching means for selecting any one of a final positioning value fetched through the final positioning value input interface unit and a positioning value obtained by the user. And the positioning value estimating unit performs estimation using the value selected by the switching means as the positioning value at the previous time.

According to a third aspect of the present invention, in the first aspect of the present invention, both the final positioning value from the positioning navigation device and the positioning value obtained by the user are input to the positioning value estimating unit, and both values are input. A positioning value at a predetermined time is estimated by performing a composite calculation using the calculated values.

According to a fourth aspect of the present invention, in the third aspect of the present invention, accompanying information of the positioning value is included as the final positioning value fetched from the positioning navigation device, and the positioning value estimating section includes The present invention is characterized in that a compound calculation is performed in consideration of information.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of the GPS receiving apparatus according to the first embodiment of the present invention. This embodiment is different from the conventional GPS receiver shown in FIG.
Is added. The other configuration is the same as that of the conventional GPS receiving apparatus shown in FIG. 5, and the same parts are denoted by the same reference numerals and description thereof will be omitted. The final positioning value input interface 16 is an interface for taking in the final positioning value obtained by the on-vehicle navigation device 3 or the like, and inputting it to the positioning value estimating unit 15. The positioning value estimating unit 15 uses the final positioning value fetched through the final positioning value input interface 16 as a previous time positioning value when estimating a positioning value at a predetermined time. Thereby, the estimation accuracy is improved as compared with the case where the positioning value of the GPS receiving device 1 is used as the previous time positioning value. Predetermined time positioning value calculation unit 1
In 3, a positioning value at a predetermined time is calculated using the positioning value at a predetermined time estimated by the positioning value estimating unit 15 and the pseudo-range and Doppler shift values which are the satellite signal measurement values at the predetermined time.

According to the present embodiment, when the positioning value at the predetermined time is calculated by the predetermined time positioning value calculating section 13, the positioning value having high estimation accuracy is used, so that the accuracy of the positioning value is improved.

FIG. 2 shows a G according to a second embodiment of the present invention.
It is a block diagram which shows the schematic structure of a PS receiver. In the present embodiment, in the GPS receiver according to the first embodiment, the output value of the predetermined time positioning value calculation unit 13 and the final positioning value input interface 16 are used as the previous time positioning value input to the positioning value estimation unit 15. A switching unit 17 capable of switching between the final positioning value captured via the control unit and the final positioning value is added. In the present embodiment, the switching unit 17
By selecting a value with higher accuracy from the two values and inputting the value to the positioning value estimating unit 15, a positioning value with higher accuracy can be obtained.

The present embodiment is intended to cope with a case where the accuracy of the positioning value output from the GPS receiver 1 is not always better than that of the on-vehicle navigation device 3. This state may occur when the vehicle-mounted navigation device 3 performs map matching using map information. Since map matching is based on the premise that cars travel on roads, mapping is performed on roads with the highest probability, and the accuracy of positioning values is larger than the road interval in the area where the vehicle is running. In this case, the error is further increased.

Accordingly, in the present embodiment, in consideration of such a situation, the switching unit 17 inputs the more accurate previous time positioning value to the positioning value estimating unit 15 so that the positioning value Accuracy can be improved.

FIG. 3 shows a G according to a third embodiment of the present invention.
It is a block diagram which shows the schematic structure of a PS receiver. As in the second embodiment, the present embodiment is intended to cope with the case where the on-vehicle navigation device 3 does not always have a higher accuracy than the positioning value output from the GPS receiver 1. . In the present embodiment, in the GPS receiving apparatus of the first embodiment, the positioning value estimating unit 15 outputs the positioning value output from the predetermined time positioning value calculating unit 13 and the final positioning value captured via the final positioning value input interface 16. You have entered both positioning values. Then, the positioning value estimating unit 15 weights and combines each of the two positioning values, and performs estimation by the Kalman filter.

Therefore, in the present embodiment, the weight is set according to the accuracy of the final positioning value output from the on-vehicle navigation device 3, so that the positioning value estimating unit 15 calculates the previous time positioning value. The estimation accuracy is improved, and the accuracy of the positioning value at a predetermined time can be improved.

FIG. 4 shows a G according to a fourth embodiment of the present invention.
It is a block diagram which shows the schematic structure of a PS receiver. In the present embodiment, in the GPS receiving apparatus of the third embodiment, in addition to the final positioning value, information on other positioning accuracy accompanying the final positioning value is also transmitted from the on-vehicle navigation device 3 to the GPS receiving apparatus 1. Is entered. The information relating to other positioning accuracy accompanying the final positioning value includes, for example, an error covariance value relating to the final positioning calculation in the on-vehicle navigation device 3 and each positioning such as the angle / angular velocity detecting means 4 and the vehicle speed signal detecting means 5. It is information on the use status of the means, and a flag indicating these is transmitted. Positioning value estimation unit 1
In No. 5, the positioning values are weighted and combined based on these pieces of information, and estimation is performed by the Kalman filter.

Therefore, in this embodiment, the positioning value estimating unit 1
5, the accuracy of the previous time positioning value is improved, and the accuracy of the positioning value at a predetermined time can be improved.

[0021]

As described above, according to the first aspect of the present invention, the pseudo distance and the Doppler between each satellite and its own position at a predetermined time from the radio wave transmitted from the GPS satellite. A pseudo-range / Doppler shift measuring unit for obtaining a shift; a positioning value calculating unit for obtaining a positioning value at a predetermined time using the pseudo-distance and Doppler shift values obtained by the pseudo-range / Doppler shift measuring unit; A positioning value estimating unit for estimating a positioning value at a predetermined time from a positioning value at a time, wherein the positioning value calculating unit takes the positioning value estimated at the positioning value estimating unit into consideration to determine the positioning value at the predetermined time. GPS seeking
The receiving device further includes a final positioning value input interface unit that captures a positioning value obtained by a positioning value calculation unit and captures a final positioning value from a positioning navigation device that determines a final positioning value, and the positioning value estimating unit includes: Since the estimation is performed by using the final positioning value as the positioning value at the previous time, a GPS receiving device with improved positioning value accuracy can be provided.

According to the second aspect of the present invention, in the first aspect of the present invention, one of the final positioning value fetched via the final positioning value input interface unit and the positioning value obtained by the user is selected. Switching means is provided, and in the positioning value estimating unit, if the estimation is performed using the value selected by the switching means as the positioning value at the previous time, the switching means can provide a more accurate previous time positioning value. Is input to the positioning value estimation unit, thereby improving the accuracy of the positioning value.

According to a third aspect of the present invention, in the first aspect of the present invention, the positioning value estimating unit inputs both the final positioning value from the positioning navigation device and the positioning value obtained by itself. If the positioning value at a predetermined time is estimated by performing a composite calculation using the values, it is possible to set the weights of the two positioning values according to the accuracy of the final positioning value output from the positioning navigation device. Thereby, the estimation accuracy of the positioning value at the previous time in the positioning value estimation unit is improved, and the accuracy of the positioning value at the predetermined time can be improved.

According to a fourth aspect of the present invention, in the third aspect of the present invention, as the final positioning value fetched from the positioning navigation device, accompanying information of the positioning value is included,
In the positioning value estimating unit, if the combined calculation is performed in consideration of the accompanying information, the accuracy of the positioning value at a predetermined time can be further improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a GPS receiving device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of a GPS receiving device according to a second embodiment of the present invention.

FIG. 3 is a block diagram illustrating a schematic configuration of a GPS receiving device according to a third embodiment of the present invention.

FIG. 4 is a block diagram illustrating a schematic configuration of a GPS receiving device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram illustrating a schematic configuration of a GPS receiver according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 GPS receiving apparatus 2 Antenna 3 Navigation apparatus mounted on a vehicle 4 Angle / angular velocity detecting means 5 Vehicle speed signal detecting means 6 Map information memory 11 Satellite signal acquisition / tracking section 12 Pseudorange / Doppler shift measuring section 13 Predetermined time side position calculating section 14 Side value output interface unit 15 Positioning value estimation unit 16 Final positioning value input interface unit 17 Switching unit

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Ikuo Tsujimoto 1048 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Works, Ltd. 72) Inventor Kazuhiro Kawamoto 1048 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Works, Ltd.

Claims (4)

[Claims] 1. A pseudorange / Doppler shift measuring unit for calculating a pseudorange and a Doppler shift between each satellite and its own position at predetermined time intervals from a radio wave transmitted from a GPS satellite, and the pseudorange. A positioning value calculation unit that obtains a positioning value at a predetermined time using a pseudo distance and a Doppler shift value obtained by a Doppler shift measurement unit, and a positioning value that estimates a positioning value at a predetermined time from a positioning value at a previous time. And a positioning value calculation unit. The positioning value calculation unit calculates the positioning value at a predetermined time by taking into account the positioning value estimated by the positioning value estimation unit. A final positioning value input interface unit that captures a final positioning value from a positioning navigation device that acquires a positioning value and obtains a final positioning value, the positioning value estimating unit converts the final positioning value to a positioning value of a previous time. A GPS receiver characterized in that estimation is performed by using the GPS receiver. And a switching unit for selecting one of a final positioning value fetched via the final positioning value input interface unit and a positioning value obtained by the user, and wherein the positioning value estimating unit includes the switching unit. 2. The GPS receiving apparatus according to claim 1, wherein the estimation is performed by using the value selected by the above as the positioning value at the previous time. 3. The positioning value estimating unit inputs both the final positioning value from the positioning navigation device and the positioning value obtained by itself, and estimates a positioning value at a predetermined time by performing a composite calculation using both values. The G according to claim 1, wherein
PS receiver. 4. The positioning device according to claim 1, wherein the final positioning value fetched from the positioning navigation device includes incidental information of the positioning value, and the positioning value estimating unit performs a composite calculation in consideration of the incidental information. The GPS receiving apparatus according to claim 3, wherein