JP2002040122A - Gps radiolocation correction system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely reduce cost for system operation by properly sending radiolocation correction data to a mobile station and increasing the efficiency, when a plurality of reference stations are provided. SOLUTION: This system is equipped with more than one reference station, which receives radiolocation data from a GPS satellite and corrects the radiolocation data and a managing device which stores radiolocation correction data obtained from the reference station, and the managing device is equipped with a packet signal transmitting means which converts the radiolocation correction data into a packet signal and sends it to a request source mobile station. The reference station sends the radiolocation correction data to the managing device, only when the numeral of the radiolocation correction data is such that its station calculates varies which exceeding a predetermined threshold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning system using GPS, and more particularly to a system for correcting a positioning error using a packet communication network.

[0002]

2. Description of the Related Art Conventionally, in a GPS positioning system, correction data calculated from positioning data received by a reference station whose position is known and an actual position is converted into positioning data of a mobile station whose position is unknown. By applying the method, the positioning position of the mobile station is improved in accuracy. For example, JP-A-11-
101865, JP-A-11-183593, JP-A-2
000-131416.

As shown in FIG. 5, the features of these inventions are as follows: the reference station 2 receives the latitude / longitude data obtained from the GPS satellite 1 and transmits the positioning correction data calculated by the reference station 2 to the mobile station 3. Is to do. Reference station 2
Since the exact position is known in advance by three-point survey,
An error of the latitude / longitude data obtained from the GPS satellite 1 is calculated and used as positioning correction data, and the positioning correction data for obtaining a more accurate positioning result is sent to the mobile station 3.

For data transmission and reception between the reference station 2 and the mobile station 3 required for realizing such a system, use of an FM carrier or a specific low-power radio has been proposed (for example, see Japanese Patent Application Laid-Open No. H11-157556). Japanese Unexamined Patent Publication No. 11-038114.

[0005]

In such a conventional positioning correction system (Differential GPS positioning system; DGPS), a reference station that calculates correction data and a mobile station that uses the correction data have the same timing at the same time. GP
If positioning is not performed with a combination of S satellites, the effect of the correction data will be significantly reduced.

[0006] However, the conventional base station for transmitting DGPS information attempts to cover a wide area in spite of its small installation location. Therefore, the distance between the base station and the base station is too wide, and the same satellite is used in the mobile station. There is a problem that the possibility of positioning is reduced by the combination of

[0007] After all, this problem can be solved by installing a large number of reference stations. However, when a large number of reference stations are installed, another new problem that data transmission and reception between the mobile station and the reference station cannot be performed smoothly is caused. This is because if a large number of positioning correction data flows from a plurality of reference stations to the mobile station, it is confused on which positioning correction data to give priority to the mobile station.

[0008] The second problem is a means for transmitting DGPS positioning information. Conventionally, as a method of transmitting positioning correction data,
FM carrier, specific low power radio, public telephone line, etc. have been proposed. However, each has problems such as a low transmission speed, a short transmission distance, and an increase in operation costs due to the amount of transmission information, which are factors that hinder the practical use (spread) of high-accuracy position positioning systems. Had become.

Therefore, an object of the present invention is to firstly improve the appropriateness and efficiency of transmission of positioning correction data to a mobile station when a plurality of reference stations are provided, and secondly, to surely reduce system operation costs. The point is to make it possible.

[0010]

In order to achieve the first object, a GPS positioning correction system according to the present invention comprises:
The system includes one or more reference stations that receive positioning data from the S satellite and correct the positioning data, and a management device that stores positioning correction data obtained from the reference station, wherein the management device determines a position from the mobile station. A packet signal transmitting means for converting the positioning correction data into a packet signal in response to the request and transmitting the packet signal to the requesting mobile station is provided.

In order to achieve the second object, the reference station sends the positioning correction data to the management device only when the numerical value of the positioning correction data calculated by the reference station fluctuates beyond a predetermined threshold value. Send Further, it is preferable that the reference station include a packet signal transmitting unit that converts the positioning correction data into a packet signal and transmits the packet signal to the management device.

[0012]

The positioning correction system according to the first aspect of the present invention includes a management device for recording the latest positioning correction data from a plurality of reference stations, and the mobile station can improve its own position data accuracy with the management device. Enhance transmission and reception.

As a result, even if a large number of reference stations are set based on, for example, a range of about 8 to 10 km in radius, the mobile station only needs to communicate with the management device, and the conventional DGP
Problems such as confusion of data and retrieval of the optimum reference station and complication of processing as in the S system do not occur. This is because the management device can select one reference station capable of performing position correction of the requesting mobile station and transmit the positioning correction data sent from the reference to the requesting mobile station.

The term "reference station capable of correcting the position of a mobile station" does not mean only the reference station closest to the mobile station. Radius 10 around the mobile station
All the reference stations existing within the range of km or less can perform high-accuracy positioning correction for the mobile station, and if there are a plurality of reference stations within the range, the management device identifies one of the reference stations. You can choose. Of course, in system operation, it is desirable to select the reference station closest to the mobile station. However, a range in which the reliability of positioning correction data can be ensured (maximum radius 10 k)
The result is the same regardless of which reference station is selected as long as the reference station is within (m) or less (there may be an error of several millimeters to several centimeters depending on the selected reference station, but it can be said that there is almost no effect in practice).

[0015] The management device according to claim 1 transmits a packet of the positioning correction data to the mobile station. This realizes instantaneous transmission of data, simultaneous processing of many data, and reduction of communication cost.

A second aspect of the present invention relates to a transmission timing of positioning correction data from the reference station to the management device. The reference station calculates the correction data based on the positioning data received from the GPS at a predetermined timing. However, according to the second aspect, only when the correction data exceeds a certain reference and a large error occurs, the management station is notified to the management device. The positioning correction data is transmitted, and in other cases, the positioning correction data is not transmitted.

This eliminates the need for each reference station to transmit the ever-changing positioning correction data when there are a plurality of reference stations, and the reference station is used by the management apparatus only when it is really necessary to perform the positioning correction of the mobile station. Sends positioning correction data to
This is for greatly reducing communication costs. Usually GP
The positioning data of the reference station transmitted from the S satellite has an error of several millimeters to several centimeters or less, but if this involves a large error of, for example, more than one meter, a result that cannot be ignored depending on the purpose of using the GPS in the mobile station. Sometimes produce. It is assumed that there are many cases where it is necessary to accurately grasp dangerous situations, such as when a trekker chooses to walk in a mountainous hill area, or when a wandering elderly person is walking on a roadway or a train track. This is because high-precision positioning correction data is always required.

In such a case, even if high-precision data can always be received via the management device, in a case where the communication cost between the reference station and the management device becomes large in an area having a large number of reference stations, it is not practical. It is difficult to build a system. Therefore, as set forth in claim 2, the cost of the service providing side is reduced, and a configuration is adopted in which as many reference stations as possible can be installed.

It is desirable that the communication between the reference station and the management device be packet transmission, and that the immediacy of data transmission based on the simultaneous processing of a large number of data be ensured and the communication cost be reduced.

Since the GPS positioning device and the packet transmission / reception device can be configured to input and output via a serial connection, a USB connection, or the like (general-purpose peripheral device interface), it is possible to correspond to many commercially available GPS receivers. Yes, the system can be configured at low cost without using a dedicated positioning device.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a high-accuracy position positioning system and a positioning correction information communication network according to an embodiment of the present invention. This embodiment includes a GPS satellite 10, a reference station 20, a mobile station 30, a position management server 40, and a packet communication network 50. The mobile station 30 is mounted on a car as an example of a land-based mobile, and the reference station 20 is a DGPS.
Are kept at an interval of 10 km or less, which allows effective use of. Although only one GPS satellite 10 is shown in FIG. 1, the operation is basically based on 24 satellites. In order to obtain effective positioning data, radio waves from four or more satellites are simultaneously received. Will be done.

Each reference station 20 always receives the positioning data transmitted from the GPS satellite 10 and obtains the difference from the accurate latitude and longitude of each reference station obtained by triangulation points or the like. It is stored in the data storage unit 25 of the reference station 20 in FIG. The stored positioning supplementary data is transmitted to the location management server 40 via the packet communication network 50 only immediately after the start of the reference station and only when the positioning supplementary data changes. The position management server 40 stores the received positioning supplementary data of each reference station in the data storage unit 43 of the position management server 40 in FIG.

The mobile station 30 determines the exact latitude and longitude at the nearest reference station before starting the movement.
0 and received via the location management server 40,
The difference is obtained from the positioning data transmitted from the S satellite 10 and stored as error correction data in the data storage unit 35 of the mobile station 30 in FIG. The stored error correction data is immediately transmitted to the position management server 40 via the packet communication network 50. The position management server 40 stores the received error correction data of each mobile station in the data storage unit 43 of the position management server 40 in FIG.

After the mobile station 30 starts moving, the mobile station transmits a position confirmation request and current positioning data to the position management server 4 via the packet communication network 50 in order to confirm its own position.
Send to 0. The position management server 40 that has received the position confirmation request selects the closest reference station from the current positioning data of the mobile station received at the same time, and stores the stored positioning supplementary data in the reference station via the packet communication network 50 for the mobile station. Send to the station. At the same time, the position management server also corrects the measured position of the mobile station and manages the current position.

In the mobile station, the positioning position is supplemented from the positioning supplementary data transmitted from the position management server 40, the error correction data of the own station, and the current positioning data, and the accurate latitude and longitude are calculated by the mobile station 30 in FIG. Is displayed on an LCD or the like by the display / output unit 36.

As described above, the packet data such as supplementary positioning data and error correction data necessary for the positioning of the mobile station can be stored in the data storage unit 43 of the position management server 40 to minimize the use of the packet communication network 50. By reducing the cost, it is possible to reduce the operation cost.

Next, the operation of the reference station 20 shown in FIG. 2 will be described. The positioning data receiver 21 receives the positioning data transmitted from the GPS satellites, and the positioning position calculator 22 calculates the positioning position of the own station. A difference is obtained from the measured position and an accurate latitude and longitude obtained at a triangulation point or the like input by the operation / input unit 27, and this difference is stored in the data storage unit 25 as supplementary positioning data. The transmission and reception of the stored positioning supplementary data and the packet data from the position management server 40 are performed by the packet data transmitting / receiving unit 24. The control of data and processing is performed by the positioning device control unit 23, and the result is stored in the L of the display / output unit 26.
It is displayed on a device such as a CD.

Next, the operation of the mobile station 30 shown in FIG. 3 will be described. The positioning data receiver 31 receives the positioning data transmitted from the GPS satellites, and the positioning position calculator 32 calculates the positioning position of the own station. Before moving, a difference is obtained from the accurate latitude / longitude received from the nearest reference station and the positioning position obtained at that time, and this difference is stored in the data storage unit 35 as error supplementary data. The transmission and reception of the stored error supplement data and the position confirmation request, the reception of the positioning supplement data, and the like are performed by the packet data transmitting / receiving unit 34. Control of data and processing is performed by the positioning device control unit 33, and the result is indicated by the L of the display / output unit 36.
It is displayed on a device such as a CD.

Next, the operation of the location management server 40 shown in FIG. 4 will be described. The packet data transmitting / receiving unit 41 transmits and receives various data to and from the reference station and the mobile station, and the data storage unit 43 stores the supplementary positioning data transmitted from the reference station and the error correction data transmitted from the mobile station. Data and processing are controlled by the position management control unit 42, and the result is displayed on a device such as an LCD of the display / output unit 44.

As described above, since the reference station, the mobile station, and the position management server have the operation / input unit and the display / output unit, respectively, in addition to transmitting and receiving the positioning correction data and the error correction data, the mobile station normally transmits the data. It is possible to transmit and receive systematic messages including the position confirmation request message. For example, in the present example, it is possible to transmit and receive communication of roads, weather conditions, or emergency situations through which a car as a mobile station has passed, or by transmitting a message as a command to a voice database provided in advance in the mobile station,
Character display and voice output are performed from the display / output unit, enabling the construction of a remote rescue system corresponding to the position situation.

[0031]

As described above, according to the present invention, the management device can supply positioning correction data to a plurality of mobile stations at the same time, so that the operation and management of the system are facilitated. In addition, since the management device uses the packet transmission means, the problems of the transmission distance, transmission speed, and operation cost of the correction data are solved, and any GPS receiver equipped with a general-purpose peripheral device interface for connecting to this system is used. Even for different models, it is possible to share high-precision position information over a wide range.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of a positioning correction system according to the present invention.

FIG. 2 is a functional block diagram of a reference station in the positioning correction system of FIG.

FIG. 3 is a functional block diagram of a mobile station in the positioning correction system of FIG.

FIG. 4 is a functional block diagram of a management device in the positioning correction system of FIG. 1;

FIG. 5 is a diagram showing a conventional positioning correction system.

[Explanation of symbols]

 Reference Signs List 10 GPS satellite 20 Reference station 21 Positioning data receiving unit 22 Positioning position calculating unit 23 Positioning device control unit 24 Packet data transmitting / receiving unit 25 Data storage unit 26 Display / output unit 27 Operation / input unit 30 Mobile station 31 Positioning data receiving unit 32 Positioning position Operation unit 33 Positioning device control unit 34 Packet data transmission / reception unit 35 Data storage unit 36 Display / output unit 37 Operation / input unit 40 Position management server 41 Packet data transmission / reception unit 42 Position management control unit 43 Data storage unit 44 Display / output unit 45 Operation / input unit 50 packet communication network

Claims (3)

[Claims] An information processing apparatus comprising: one or more reference stations for receiving positioning data from a GPS satellite and correcting the positioning data; and a management device for storing positioning correction data obtained from the reference station. A GPS positioning correction system comprising: a packet signal transmitting unit that converts the positioning correction data into a packet signal in response to a position confirmation request from a station and transmits the packet signal to a requesting mobile station. 2. The reference station transmits the positioning correction data to the management device only when the numerical value of the positioning correction data calculated by the reference station fluctuates beyond a predetermined threshold value. The GPS positioning correction system according to claim 1. 3. The G according to claim 1, wherein the reference station includes packet signal transmitting means for converting the positioning correction data into a packet signal and transmitting the packet signal to the management device.
PS positioning correction system.