JPH1062514A - Gps error correction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To furthermore improve the precision of position information without applying a large-scaled device to an existing device. SOLUTION: First difference data d1 are made on the basis of positioning data obtained with a first GPS receiver 15 at an already known position. Second difference data d2 are made on the basis of position measuring data obtained with a second GPS receiver 21 at the other position. Correction data (c) from a reference station 6 are obtained with a DGPS (Differential correction system) receiver 16. An error information distribution means 33 transfers one of the first difference data d1 or the correction data (c) as the second difference data d2 are made reference as optimum error information (e). Therefore the self position of each golf cart can be accurately grasped only by adding the DGPS receiver 16 and the second GPS receiver 21 to an existing device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a GPS error correction device using a global positioning system (GPS).

[0002]

In general, a positioning position obtained by using a GPS receiver, that is, position information, is an essential error factor such as a satellite clock, an orbit error, a radio wave delay due to the ionosphere and the atmosphere. In addition to the above, an error factor called “selectable availability” (S / A) due to intentional deterioration of accuracy of the operator is included. For this reason, for example, in a golf course or the like, when a GPS receiver is incorporated in an individual golf cart as a mobile station to obtain position information of each golf cart, the position of the golf cart in the entire golf course is reduced and displayed. In this case, some error factors included in the position information do not have much effect, but if the distance to the green is accurately displayed in units of one yard to provide information to the player, the position information The error factors included are so large that they cannot be ignored.

In order to cope with such a problem, for example, Japanese Patent Application Laid-Open No. Hei 6-230105 discloses a specific means for simply correcting an error in position information obtained from a GPS receiver. This consists of a fixed station with a fixed GPS receiver installed at a known coordinate position, and a plurality of mobile stations each with a mobile GPS receiver, and the fixed station sequentially calls each mobile station by polling. And the corresponding mobile station transmits the measured position from the mobile GPS receiver to the fixed station, and the fixed station calculates the difference between the measured position obtained by the fixed GPS receiver and the true coordinate position as difference data. The position information from the mobile station is corrected based on the difference data, and the corrected position information is sent back to the mobile station.

In such a GPS error correction apparatus, a fixed station equipped with a fixed GPS receiver is simply installed at a point where an accurate coordinate position is known, and data is transmitted and received between the fixed station and each mobile station. There is an advantage that the measured position of each mobile station can be easily corrected. However, due to the performance of a fixed GPS receiver that receives a GPS satellite signal from an artificial satellite and various other factors, the difference data is not always accurate, and the accuracy of the device is improved. Therefore, the current configuration was insufficient.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a GPS error correction device capable of further improving the accuracy of position information without making any major changes to existing devices.

[0006]

In order to achieve the above object, a GPS error correction apparatus according to the present invention comprises a fixed station and a movable mobile station, wherein the fixed station has a known first station.
A first GPS receiver provided at a coordinate position and receiving a GPS satellite signal from an artificial satellite, and a second GP provided at a known second coordinate position and receiving a GPS satellite signal from the artificial satellite
S receiver, a DGPS receiver for receiving correction data of a GPS satellite signal from a reference station, and a difference between a positioning position obtained by the first GPS receiver and the true first coordinate position.
First difference data calculation means for calculating as difference data;
Calculating a difference between the measured position obtained by the second GPS receiver and the true second coordinate position as second difference data;
The first difference data obtained by the first difference data calculation means and the difference data obtained by the DGPS receiver are determined based on a comparison between the difference data calculation means and the second difference data obtained by the second difference data calculation means. Error information distributing means for distributing any one of the corrected data to the mobile station as error information, the mobile station comprising: a mobile GPS receiver for receiving a GPS satellite signal from the artificial satellite; And a position correcting means for correcting the measured position obtained by the mobile GPS receiver based on the error information from the information distributing means to obtain the position information of the mobile station.

[0007] According to the above configuration, on the fixed station side, the first difference data calculating means obtains the difference based on the second difference data of another point created based on the positioning data obtained by the second GPS receiver. The first difference data is compared with the correction data from the reference station, which is the information providing source of the DGPS correction system, and one of the optimum data is transferred to the mobile station as error information. On the basis of this error information, it is possible to accurately grasp its own position. In addition, by simply adding a second GPS receiver having the same performance as the first GPS receiver and a DGPS receiver to an existing device, without extensively modifying the device,
Significant improvement in accuracy can be achieved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a GPS error correction device of the present invention applied to a golf course will be described in detail with reference to the accompanying drawings. First, referring to FIG. 1 showing a schematic configuration of the entire apparatus, reference numeral 1 denotes a known artificial satellite on which an atomic clock is mounted, and from this artificial satellite 1, an extremely accurate GPS satellite signal is transmitted at a specific center frequency. It is open to the public and can be freely received on the earth. Reference numeral 2 denotes a plurality of golf carts corresponding to mobile stations movable within a course of a golf course.
A mobile GPS receiver 3 for receiving a GPS satellite signal from the artificial satellite 1, a mobile station control means 4 for calculating and processing a positioning position of the golf cart 2 obtained from the mobile GPS receiver 3, that is, positioning data, And a wireless device 5 for transmitting and receiving data to and from the fixed station 11.

[0009] Each golf cart 2 is accompanied by several players (not shown) forming a set of parties, each not shown, and each party starts in a predetermined order and travels along the course of the golf course. I'm moving. In the following description, the golf cart 2 is referred to as 2a → 2b → 2c for convenience.
It is assumed that they are moving in the order of →→ 2z → 2a. In this case, the golf cart that starts first is 2a, and the golf cart that starts last is 2z. On the golf course, while traveling on the course, the golf cart 2a that starts first becomes the golf cart that starts last. 2
It may be behind z.

Reference numeral 6 denotes a reference station of a differential correction system (hereinafter, simply referred to as DGPS). The precise position of the reference station 6 is measured in advance, and each GP received from the plurality of artificial satellites 1 is determined based on the accurate position.
An error component of the pseudorange, time information, and orbit data included in the S satellite signal is detected and transmitted to the user as correction data. The correction data transmitted from the reference station 6 is updated every predetermined time, for example, every 5 seconds.

In this embodiment, reference numeral 11 denotes a fixed station installed at an appropriate place in a golf course, which is, for example, a first fixed station 12 installed at a known first coordinate position such as inside a club house. The first fixed station 12 is connected to the first fixed station 12 by the communication means 13 and includes a second fixed station 14 installed at a known second coordinate position such as in a golf course. And
The first fixed station 12 has a first GPS receiver 15 for receiving a GPS satellite signal from the artificial satellite 1 and a G
DGPS receiver 16 for receiving correction data of PS satellite signal
And a first fixed station control means for arithmetically processing the positioning position of the first fixed station 12 obtained from the first GPS receiver 15, that is, positioning data and the correction data obtained from the DGPS receiver 16
And a wireless device 18 for transmitting and receiving data to and from each golf cart 2. Then, not only between the first fixed station 12 and each golf cart 2 but also each golf cart 2
Bidirectional data transmission is performed by the wireless devices 5 and 18.

On the other hand, a second fixed station located at a different position from the first fixed station 12
The fixed station 14 includes a second GPS receiver 21 for receiving a GPS satellite signal from the artificial satellite 1 and a second GPS receiver 21.
And the second fixed-station control means 22 for calculating and processing the positioning position of the second fixed station 14, that is, positioning data obtained from the second fixed station 14. It should be noted that the function of the second fixed station control means 22 may be shared by the first fixed station control means 17 and the positioning data from the second GPS receiver 21 may be directly transmitted to the first fixed station control means 17. . The communication means 13 can be either wired or wireless.

Next, the configuration inside the fixed station 11 will be described with reference to FIG. The first fixed station control means 17 and the second fixed station control means 22 include a CPU (not shown) having an arithmetic processing function.
In addition, storage means such as ROM and RAM, A / D, D
Each of them is provided with input / output interface means such as an A / A converter and time measuring means. Then, the second fixed station control means 22 has, as a function of the control sequence stored in its own storage means, the positioning data of the second fixed station 14 obtained from the second GPS receiver 21 and the pre-stored true data. The second difference data calculating means 26 for calculating the difference data d2 with the second coordinate position is provided.

Reference numeral 31 denotes an input key as an operating means of the first fixed station control means 17, and 32 denotes a display such as a CRT which is also connected to the first fixed station control means 17. The first fixed station control means 17 includes, as a function of the control sequence stored in its own storage means, the positioning data of the first fixed station 12 obtained from the first GPS receiver 15 and the real stored data of the first fixed station 12. A difference data calculating means 25 for calculating difference data d1 from one coordinate position is provided. Further, the first fixed station control means 17 includes the second difference data d2 obtained by the second difference data calculation means 26 and the first difference data d1 obtained by the first difference data calculation means 25, and 2 difference data d2 and D
The correction data c obtained by the GPS receiver 16 is compared with each other, and the weather condition previously input by the input key 31 and the position of the artificial satellite 1 obtained from each of the receivers 15, 16, 21 are considered. Thus, the first difference data d1 and the correction data c
Is provided to each golf cart 2 as error information e. The error information e obtained by the error information distribution means 33 is
The transmission means 34 of 18 transmits the data to all the golf carts 2 at a time (broadcast).

In addition to the transmitting means 34, the wireless device 18 can output corrected position information p sequentially transmitted from each golf cart 2.
And the like. The latest position information p of each golf cart 2 obtained by the receiving means 35 is stored and managed in the golf cart position managing means 36 of the first fixed station control means 17. Also, the first fixed station control means 17
Is provided with a display control means 37 for controlling the display of the display 22 based on an input operation from the input key 31, for example. The display control means 37 stores the map information of the golf course, and displays the position of each golf cart 2 after the start of the play together with the whole or partial map screen of the golf course as necessary. 22 can be displayed.

On the other hand, the configuration inside each golf cart 2 will be described with reference to FIG. 3. The mobile station control means 4 is similar to the first fixed station control means 17 and the second fixed station control means 22 in that the
U, storage means, input / output interface means, timekeeping means, and the like. An input key 41 as an operating means of the mobile station control means 4 and a display 42 such as a small liquid crystal display are connected to the input / output ports of the mobile station control means 4, respectively. The radio 5 of each golf cart 2
Receiving means 44 for receiving the error information e transmitted from the transmitting means 34 of the first fixed station 12 and receiving the position information p 'transmitted from the transmitting means 45 of another golf cart 2 described below is provided. The error information e received here is transferred to the golf cart position correcting means 46 of the mobile station control means 4, while the position information p 'of another golf cart 2 is transferred to the golf cart position of the mobile station control means 4. It is transferred to the management means 47.

The golf cart position correcting means 46 corresponding to the position correcting means is provided with the error information distribution means received by the receiving means 44.
Based on the error information e from 33, the movement G of the golf cart 2
This is for correcting the measured position obtained by the PS receiver 3, and the corrected measured position of the golf cart 2 is stored in the golf cart position management means 37 as position information p. The golf cart position management means 37 not only stores and manages the latest position information p of the golf cart 2 itself, but also stores and manages the latest position information p 'of the other golf cart 2 obtained by the receiving means 44. It has a function to do. Further, the mobile station control means 4 includes a display control means 48 for controlling display on the display 42 based on an instruction from the input key 41. The wireless device 5 is provided with a transmitting means 45 for simultaneously transmitting the position information p obtained by the golf cart position correcting means 46 to the receiving means 35 of the first fixed station 12 and the receiving means 44 of another golf cart 2. ing.

Next, the operation of the above configuration will be described with reference to a fixed station.
The eleventh operation procedure will be described with reference to the explanatory diagram of FIG. As a prerequisite, the first fixed station 12 and the second fixed station 14 measure the true values of their coordinate positions (first coordinate position, second coordinate position) in advance by surveying or the like, and calculate the true values of the first difference data. Means 25 and second difference data calculation means
26.

First, in the period T1, the transmitting means of the radio 15
An operation of sending out error information e from 34 is performed. Specifically, the GPS satellite signals from the plurality of artificial satellites 1 are
When the signal is received by the PS receiver 15, the first difference data calculating means 25
Performs the position detection by comparing the coordinates of the satellites included in the GPS satellite signal of each artificial satellite 1 and the time at which the signal is output with the time at which the GPS satellite signal is received, and compares the position detection result with the first. It is stored as positioning data of the fixed station 12.
Then, the first difference data calculating means 25 calculates the difference between the positioning data and the pre-stored true first coordinate position of the first fixed station 12, and uses this as the first difference data d1. To send out.

Similarly, when the second GPS receiver 21 sequentially receives GPS satellite signals from the plurality of artificial satellites 1,
The second difference data calculating means 26 compares the coordinates of the satellites included in the GPS satellite signal of each artificial satellite 1 and the time at which the signal was output with the time at which the GPS satellite signal was received to detect the position, This position detection result is stored as positioning data of the second fixed station 14. Then, the second difference data calculating means 26 calculates the positioning data and the second fixed station 14 stored in advance.
Is calculated and the difference from the true second coordinate position is calculated and sent to the error information distribution means 33 as second difference data d2.

On the other hand, the DGPS receiver 16 receives the correction data c of each artificial satellite 1 transmitted from the reference station 6 every moment and transfers it to the error information distribution means 33. The error information distributing means 33 is provided with the second difference data calculating means 26.
Based on the difference data d2, the second difference data d2
Is compared with the first difference data d1 or the correction data c, and one of the data is sent to the transmitting means 34 as the optimum error information e. Note that it is preferable to take into account the weather conditions at that time, the position of the artificial satellite 1 received by the first GPS receiver 15 and the second GPS receiver 21, and the like, as judgment materials for obtaining the error information e. Thereby, more appropriate error information e can be obtained. Then, the transmission unit 34 of the wireless device 18 transmits the error information e obtained by the error information distribution unit 33 to each golf cart 2 in a lump.

On each golf cart 2 side, when the error information e is received by the receiving means 44 of the wireless device 5, it is immediately transferred to the golf cart position correcting means 46 of the mobile station control means 4. The golf cart position correcting means 36 calculates the positioning position of the golf cart 2 itself as positioning data based on the output from the mobile GPS receiver 3, and subtracts the error included in the error information e from the positioning data. , And calculates the corrected position information p. Each golf cart 2 displays, for example, the distance to the green based on the correction data c obtained by the golf cart position correcting means 46,
The current position of the golf cart 2 on the map is displayed on the display 42 provided. Further, the position information p of each golf cart 2 is stored in the golf cart position management means 47 until the next error information e is transmitted from the first fixed station 12.

As in the embodiment, the mobile station is a golf cart 2
, The transmission interval T of the error information e from the fixed station 11
Is preferably about once every 30 seconds. As a result, the next error information e can be received within a range that is not far from each golf cart 2 after obtaining the accurate error information e. That is, the transmission interval T of the error information e may be appropriately changed according to the moving speed of the mobile station and the number of mobile stations.

In the next period T2, the specific golf carts 2 are sequentially called by the polling function of the first fixed station 12. Then, the called golf cart 2 transmits the position information p indicating its exact position stored in the golf cart position management means 47 to the transmission means 45 of the golf cart 2.
To the receiving means 35 of the first fixed station 12. The return of the position information p from each golf cart 2 is repeatedly performed with an emergency communication allocation period T3 to be described later interposed therebetween. Therefore, the golf cart position management means 36 of the first fixed station 12
Is the position information p sequentially returned from the golf cart 2.
, It is possible to accurately grasp the positions of all the golf carts 2.

When the golf cart 2 transfers its own correction data c, the position information p 'of the other golf cart 2 is received not only by the fixed station 12 but also by the receiving means 44 of the nearby golf cart 2. You. Thereby, each golf cart 2 can grasp not only its own exact position but also the exact position of the surrounding golf carts 2.

The period T3 is allocated for emergency communication. Specifically, for example, player injuries,
An emergency button (not shown) provided on each golf cart 2 when a situation such as a failure of the golf cart 2 occurs.
Is operated, the emergency signal from the golf cart is received by the wireless device 18 of the first fixed station 12 during the period T3.
Upon receiving this emergency signal, the fixed station 12 can immediately take necessary measures. In the embodiment, this period T3
Are provided repeatedly, but the number of times of the period T3 may be reduced or omitted in order to shorten the transmission interval of the difference data d.

As described above, in the present embodiment, the fixed station 11 side generates the first difference data d1 simply created based on the positioning data obtained by the first GPS receiver 15 by using the error information e.
Not only the first difference data d1 but also the first difference data d1 based on the second difference data d2 of another point created based on the positioning data obtained by the second GPS receiver 21.
And the reference station 6 which is a source of information of the DGPS correction system
Is compared with the correction data c, and one of the optimum data is transferred to each golf cart 2 as error information e. Therefore, each golf cart 2 side, based on this error information e, It becomes possible to grasp the position of oneself more accurately than ever. Also, a second GPS receiver 21 having the same performance as the first GPS receiver 15 is added to an existing device, and a DGP
By simply adding the S receiver 16, it is possible to greatly improve the accuracy as described above without making a major modification to the device.

That is, it is provided at a known first coordinate position,
First GPS receiving GPS satellite signal from artificial satellite 1
A receiver 15 and a second GPS receiver 21 provided at a known second coordinate position and receiving a GPS satellite signal from the artificial satellite 1
And a DGPS receiver 16 for receiving correction data c of the GPS satellite signal from the reference station 6, and a difference between the positioning position obtained by the first GPS receiver 15 and the true first coordinate position as first difference data d1. A first difference data calculating means 25 for calculating; a second difference data calculating means 26 for calculating a difference between the measured position obtained by the second GPS receiver 21 and a true second coordinate position as second difference data d2; Based on the comparison with the second difference data d2 obtained by the second difference data calculation means 26, the first difference data d1 obtained by the first difference data calculation means 25 is obtained.
And the correction data c obtained by the DGPS receiver 16 as the error information e.
The fixed station 11 is provided with an error information distribution means 33 for distributing the GPS information to the mobile station G while receiving the GPS satellite signal from the artificial satellite 1.
Error information e from the PS receiver 3 and the error information distribution means 33
The golf cart 2 is provided with a golf cart position correcting means as a position correcting means for obtaining the position information of the golf cart 2 by correcting the positioning position obtained by the mobile GPS receiver 3 based on the GPS. It is possible to further improve the accuracy of the position information without adding any trouble.

Incidentally, when positioning is performed at the same time using the mobile GPS receiver 3 and the first GPS receiver 15 in a specific area (for example, in the same golf course), error factors due to the influence of the ionosphere and the atmosphere. It is considered that the error due to S / A is distributed almost uniformly, and the error in the positioning data obtained by the first GPS receiver 15 of the first fixed station 12 at a certain time is the GPS error of each golf cart 2. Receiver 3
Is substantially equal to the error in the positioning data obtained in step (1). Therefore, the golf cart position correcting means 46 of each golf cart 2
Is the first difference data d from the first difference data calculating means 25
1 is sent as error information e, the first fixed station
The positioning data when the mobile GPS receiver 3 receives the same GPS satellite signal as the artificial satellite 1 received by the 12 first GPS receivers 15 and emitted at the same time is corrected by the error information e. For example, each golf cart 2 can obtain the position information p with the highest accuracy. To do so, which data (first difference data d1
Alternatively, it is preferable to transmit a code indicating whether the correction data c) has been adopted.

As shown by the broken line in FIG. 1, a DGPS receiver 51 is provided for each golf cart 2 on the mobile station side.
The correction data c from the reference station 6 obtained by the DGPS receiver 51 may be compared with the error information e by the golf cart position correction means 46 to correct the positioning data. With such a configuration, the error information e sent from the fixed station 11 is corrected by the golf cart 2 using the correction data c.
And more accurate position information p can be obtained.

Further, each golf cart 2 can correct its own position by the golf cart position correcting means 46 based on the common error information e transmitted from the fixed station 11, as in the conventional case. The processing time can be remarkably reduced as compared with a method in which the individual golf carts 2 are called from the fixed station 11 and error information is distributed. In particular, even if a large number of golf carts 2 move within the golf course, the time until each golf cart 2 obtains its own error information e does not change.
On the other hand, if the error information e is sent out at appropriate intervals, the position of the moving golf cart 2 can be relatively accurately grasped.

Each golf cart 2 of this embodiment is configured such that the position information p corrected by the golf cart position correcting means 46 can be received by the receiving means 44 of another golf cart 2. Therefore, since each golf cart 2 can also receive the position information p ′ transmitted from the nearby golf carts 2, it knows not only its own accurate position but also the exact position of the nearby golf carts 2. It becomes possible.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, in the embodiment, a device for centrally controlling the position of the golf cart 2 has been described.
The present invention can be applied to any device including a fixed station and a mobile station having a PS receiver.

[0034]

The GPS error correction apparatus of the present invention comprises a fixed station and a movable mobile station.
A first GPS receiver provided at a known first coordinate position and receiving a GPS satellite signal from an artificial satellite, a second GPS receiver provided at a known second coordinate position and receiving a GPS satellite signal from the artificial satellite, A DGPS receiver for receiving correction data of a GPS satellite signal from a reference station;
First difference data calculating means for calculating, as first difference data, a difference between the measured position obtained by the S receiver and the true first coordinate position, and a true difference between the measured position obtained by the second GPS receiver and the true position A second difference data calculation unit that calculates a difference from the second coordinate position as second difference data; and a first difference calculation unit that determines the first difference based on a comparison determination between the second difference data obtained by the second difference data calculation unit. Error information distribution means for distributing any one of the first difference data obtained by the data calculation means and the correction data obtained by the DGPS receiver to the mobile station as error information, the mobile station comprising: A mobile GPS receiver for receiving a GPS satellite signal from an artificial satellite, and the mobile GPS receiver based on error information from the error information distribution means.
Position correcting means for correcting the positioning position obtained by the PS receiver to obtain the position information of the mobile station, and further improving the accuracy of the position information without adding a large amount of work to the existing device. It can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of an entire apparatus showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of the fixed station.

FIG. 3 is a block diagram showing a configuration of each golf cart.

FIG. 4 is an explanatory diagram showing an operation procedure of the fixed station.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Artificial satellite 2, 2a-2z Golf cart (mobile station) 3 Mobile GPS receiver 6 Reference station 11 Fixed station 15 1st GPS receiver 16 DGPS receiver 21 2nd GPS receiver 25 1st difference data calculation means 26 2nd difference data Calculation means 33 Error information distribution means 46 Golf cart position correction means (position correction means)

Claims (1)

[Claims] 1. A fixed station comprising a fixed station and a movable mobile station, wherein the fixed station is provided at a known first coordinate position and receives a GPS satellite signal from an artificial satellite, and a known GPS receiver. G from the satellite provided at the second coordinate position
A second GPS receiver for receiving a PS satellite signal; a DGPS receiver for receiving correction data of a GPS satellite signal from a reference station; and a difference between a positioning position obtained by the first GPS receiver and the true first coordinate position. First difference data calculating means for calculating a difference as first difference data; and second difference calculating means for calculating a difference between the measured position obtained by the second GPS receiver and the true second coordinate position as second difference data. The first difference data obtained by the first difference data calculation means and the first difference data obtained by the DGPS receiver are determined based on a comparison between the data calculation means and the second difference data obtained by the second difference data calculation means. Error information distribution means for distributing any one of the corrected data to the mobile station as error information, the mobile station receives a GPS satellite signal from the artificial satellite, a mobile GPS receiver, And a position correcting means for correcting the positioning position obtained by the mobile GPS receiver based on the error information from the error information distributing means to obtain the position information of the mobile station. apparatus.