JPH09304504A - Gps error correcting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make many mobile stations possible to grasp their own positions accurately at short intervals. SOLUTION: A fixed station 12 transmits the difference between the measured position data obtained from a GPS receiver 13 and the true coordinates position as the difference data. Each golf cart 2 corrects the measured position data from a GPS receiver 3 when the difference data are received. Thereore, the processing time can be shortened strigingly in comparison with the case, wherein each golf cart 2 is called up from the fixed station 2 and the distributing transmission of the correcting data is performed. This processing time is not changed even if the number of the golf carts 2 is increased.

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 equipped with a fixed GPS receiver installed at a known coordinate position and a plurality of mobile stations each equipped with a mobile GPS receiver. The fixed station sequentially calls individual mobile stations by polling. Then, the corresponding mobile station transmits the positioning position from the mobile GPS receiver to the fixed station, and at the fixed station side, the difference between the positioning position obtained by the fixed GPS receiver and the true coordinate position is calculated as difference data. Then, the positioning position from the mobile station is corrected based on this difference data, and the corrected positioning position is sent back to the mobile station side.

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, since the fixed station needs to sequentially call each mobile station by polling and deliver the corrected positioning position, it takes a considerable amount of time for all the mobile stations to obtain new corrected positioning position data. It costs.
In particular, when there are a large number of mobile stations, the mobile station moves to a distant place while transmitting / receiving data to / from another mobile station, which makes it difficult to grasp the accurate position.

Another drawback of such a polling function is that data is transmitted and received only between a fixed station and a specific mobile station, so that each mobile station determines the exact position of the surrounding mobile stations. I can't figure it out. Therefore, in the example of the golf cart on the above-mentioned golf course, the positions of the golf carts in front of and behind the player cannot be grasped at all, and players in front of and behind in a particular place are concentrated, or If the players are too far apart, it may interfere with the progress of play.

In view of the above problems, it is a first object of the present invention to provide a GPS error correction device which enables a large number of mobile stations to accurately grasp their positions at short intervals.

A second object of the present invention is to provide a GPS error correction device which can accurately ascertain the position of another mobile station around itself.

[0008]

In order to achieve the first object, the GPS error correction apparatus of the present invention according to claim 1 is arranged so that a radio wave from an artificial satellite is transmitted to a fixed station installed at a known coordinate position. And a mobile GPS receiver capable of receiving radio waves from an artificial satellite in each of a plurality of movable mobile stations, and the fixed station is obtained from the fixed GPS receiver. Difference data calculating means for calculating difference data between the measured position of the fixed station and the true coordinate position, and difference data transmitting means for collectively transmitting the difference data obtained by the difference data calculating means to all the mobile stations. Each of the mobile stations further comprises a differential data receiving means for receiving differential data from the differential data transmitting means of the fixed station, and each mobile station based on the differential data received by the differential data receiving means. Further comprising constructed and position correcting means for correcting the measured position obtained from the mobile GPS receiver of the station.

According to this structure, each mobile station can correct its own position by the position correcting means based on the common difference data transmitted from the fixed station. The processing time can be significantly shortened as compared with the case where each mobile station is called from the station side and correction data is distributed. In particular, even when a large number of mobile stations are moving, the time until each mobile station obtains its corrected position does not change, so differential data is sent from the fixed station to each mobile station at appropriate intervals. As long as it is sent out, it becomes possible to relatively grasp the position of the moving mobile station.

Further, in the GPS error correction apparatus of the present invention according to claim 2, in order to achieve the second object as well, each mobile station uses the positioning position corrected by the position correction means as correction data. It further comprises correction data transmitting means for transmitting to the fixed station, and correction data receiving means for receiving the correction data transmitted from the correction data transmitting means of another mobile station.

In this configuration, each mobile station can receive the correction data transmitted from the peripheral mobile stations, so that not only the accurate position of itself but also the accurate position of the peripheral mobile stations are grasped. It will be possible.

[0012]

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 is a well-known artificial satellite equipped with an atomic clock, and an extremely accurate time signal wave is transmitted from this artificial satellite 1 at a specific center frequency. It is open to the public and can be freely received on the earth.
2 is a plurality of golf carts corresponding to mobile stations that can move within the course of the golf course.
Mobile GP capable of receiving time signal waves from the artificial satellite 1
A GPS receiver 3 which is an S receiver, a mobile station control means 4 for calculating the positioning position of the golf cart 2 obtained from the GPS receiver 3, that is, positioning data, and a radio device for transmitting and receiving data to and from a fixed station 12 described later. 5 and. Although not shown, each golf cart 2 has several players
We make a group of parties to accompany, and each party starts in a predetermined order and moves on the course of the golf course. In the following description, it is assumed that the golf cart 2 moves in the order of 2a → 2b → 2c → ... → 2z → 2a for convenience. In this case, the golf cart that starts first is 2a, and the golf cart that starts last is 2z, but the golf cart 2a that started first on the way on the golf course is
It may be behind the golf cart 2z that started last.

Reference numeral 12 is a fixed station installed at a known coordinate position, for example, inside a club house attached to the fixed house. The fixed station 12 is a fixed GPS capable of receiving a time signal wave from the artificial satellite 1. GPS receiver 13 which is a receiver and this G
A fixed station control means 14 for calculating the positioning position of the golf cart 2 obtained from the PS receiver 13, that is, positioning data;
A radio 15 for transmitting and receiving data to and from each golf cart 2 is provided. Then, not only between the fixed station 12 and each golf cart 2, but also each golf cart 2 is connected to the radio 5,
15 allows bidirectional data transmission.

Next, the internal structure of the fixed station 12 will be described with reference to FIG. The fixed station control means 14 includes a CPU having an arithmetic processing function (not shown), storage means such as ROM and RAM, input / output interface means such as A / D and D / A converters, and clocking means. Are built in each. Reference numeral 21 is an input key as an operating means of the fixed station control means 14, and 22 is a display device such as a CRT. The fixed station control means 14 calculates difference data d between the positioning data of the fixed station 12 obtained from the GPS receiver 13 and the previously stored true coordinate position as a function of the control sequence stored in the storage means. The difference data calculating means 23 is provided. The difference data d obtained by the difference data calculating means 23 is transmitted from the difference data transmitting means 24 of the wireless device 15 to all golf carts 2 at once (broadcast).

In addition to the difference data transmitting means 24, the wireless device 15 is provided with a correction data receiving means 25 for receiving the correction data c sequentially transmitted from each golf cart 2. Then, the correction data c obtained by the correction data receiving means 25
Is stored and managed as the latest position information of each golf cart 2 in the golf cart position management means 26 provided in the fixed station control means 14. In addition, the fixed station control means 14
A display control means 27 for controlling the display of the display 22 based on an instruction from 21 is provided. The display control means 27 stores golf course map information, and displays the position of each golf cart 2 after the start of play together with the whole or partial map screen of the golf course, if necessary. It can be displayed on 22.

On the other hand, the structure of each golf cart 2 will be described with reference to FIG. 3. The mobile station control means 4, like the fixed station control means 14, has a CPU, a storage means, an input / output interface means, and a clock means. And so on. In addition, an input key 31, which is an operation means of the mobile station control means 4,
A display 32 such as a small liquid crystal display is connected to the input / output port of the mobile station control means 4. The wireless device 5 of each golf cart 2 includes a difference data receiving unit 33 that receives the difference data d transmitted from the difference data transmitting unit 24 of the fixed station 12 and a correction data transmitting unit 35 described later of another golf cart 2. The correction data receiving means 34 for receiving the correction data c ′ transmitted is provided, and while the difference data d received by the difference data receiving means 33 is transferred to the golf cart position correcting means 36 of the mobile station control means 4, The correction data c ′ received by the correction data receiving means 34 is different from the golf cart 2
Is transferred to the golf cart position management means 37 of the mobile station control means 4.

The golf cart position correcting means 36 corresponding to the position correcting means corrects the positioning position obtained from the GPS receiver 3 of the golf cart 2 based on the difference data d received by the difference data receiving means 33. The corrected position of the golf cart 2 corrected here is stored in the golf cart position management means 37 as correction data c. The golf cart position management means 37 not only stores and manages the latest position information of its own golf cart 2 as the correction data c, but also the latest position information of the other golf carts 2 obtained by the correction data receiving means 34. Is stored and managed as correction data c ′. Also, the mobile station control means 4
Display control means 38 for controlling the display of the display 32 based on an instruction from the input key 31 is provided. In addition to the difference data receiving means 33 and the correction data receiving means 34 described above, the wireless device 5 receives the correction data c obtained by the golf cart position correcting means 36 from the correction data receiving means 25 of the fixed station 12 and the separate data. The correction data transmitting means 35 for simultaneously transmitting to the correction data receiving means 34 of the golf cart 2 is provided.

Next, the operation of the above configuration will be described with reference to a fixed station.
The 12 operation procedures will be described with reference to the explanatory diagram of FIG. As a precondition, it is assumed that the true value of the coordinate position of the position of the fixed station 12 is measured in advance by surveying or the like and is stored in the difference data calculation means 23 of the fixed station control means 14. First, in the period T1, the operation of sending out the difference data d from the difference data transmitting means 24 of the wireless device 15 is performed. Specifically, when the GPS receiver 13 receives the time signal waves from the plurality of artificial satellites 1, the difference data calculating means 23
Compares the satellite coordinates included in the time signal wave of each artificial satellite 1 and the time at which the signal was issued with the time at which the time signal wave was received to detect the position, and the position detection result is used as the fixed station. Stored as 12 positioning data. The difference data calculation means 23 calculates the difference between the positioning data and the true coordinate position of the fixed station 12 stored in advance, and uses this as difference data d from the difference data transmission means 24 of the wireless device 15 to each golf cart 2 collectively. Send.

On the side of each golf cart 2, when the difference data receiving means 33 of the wireless device 5 receives the difference data, this immediately causes the golf cart position correcting means of the mobile station control means 4 to receive the difference data.
Transferred to 36. The golf cart position correcting means 36 is a GP
Based on the output from the S receiver 3, the detected position of the golf cart 2 of its own is calculated as positioning data, and the difference data is subtracted from this positioning data to calculate the correction data c indicating the corrected position of the golf cart 2. . Based on the correction data c obtained by the golf cart position correcting means 36, each golf cart 2 displays, for example, the distance to the green by a yard, or the current position on the map of the golf cart 2 on a built-in display. Display at 32. Further, the correction data c of each golf cart 2 is stored in the golf cart position management means 37 until the fixed station 12 transmits the next difference data d.

When the golf cart 2 is a mobile station, the transmission interval T of the differential data d from the fixed station 2 is about 1 in about 30 seconds.
It is preferable to make it about once. As a result, each golf cart 2 can receive the next difference data d within a range not so far after the correct correction data c is obtained.
The transmission interval T of the difference data d may be appropriately changed according to the moving speed of the mobile station and the number of stations.

During the next period T2, the particular golf cart 2 is called in sequence by the polling function of the fixed station 12. Then, the called golf cart 2 returns the correction data c, which is stored in the golf cart position management means 37 and indicates the accurate position of itself, from the correction data transmission means 35 to the correction data reception means 25 of the fixed station 12. To do. The return of the correction data c from each golf cart 2 is repeatedly performed by interposing an allocation period T3 for emergency communication, which will be described later. Therefore, the golf cart position management means 26 of the fixed station 12,
The positions of all the golf carts 2 can be grasped based on the correction data c sequentially returned from the golf carts 2.

Further, a particularly important point here is that, when the golf cart 2 transfers its own correction data c, the correction data receiving means of not only the fixed station 12 but also the peripheral golf carts 2 is received.
Even in 34, it can be received as the correction data c ′ of another golf cart 2. As a result, each golf cart 2 can grasp not only its own accurate position but also the surrounding golf cart 2's accurate position.

The period T3 is assigned 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.
When is operated, the emergency signal from the golf cart is received by the wireless device 5 of the fixed station 12 in the period T3. Upon receiving this emergency signal, the fixed station 12 can immediately take necessary measures. Although the period T3 is also repeatedly provided in the embodiment, 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.

By the way, when positioning is performed at the same time using the GPS receivers 3 and 13 in a specific area (for example, in the same golf course), error factors due to the influence of the ionosphere and the atmosphere, S / It is considered that the error due to A is distributed almost uniformly, and the error of the positioning data obtained by the GPS receiver 13 of the fixed station 12 at a certain time is equal to that of each golf cart 2.
The error of the positioning data obtained by the GPS receiver 3 is almost equal. Therefore, the golf cart position correcting means 36 of each golf cart 2 receives the time signal wave of the same satellite 1 as the GPS receiver 13 of the fixed station 12 emitted at the same time when the GPS receiver 3 receives the time signal wave. If the positioning data of is used, the most accurate correction data c can be obtained.

Further, since each golf cart 2 can correct its own position by the golf cart position correcting means 36 based on the common difference data d transmitted from the fixed station 12, as in the conventional case. As compared with the case where the fixed station 12 calls the individual golf carts 2 and distributes the correction data c, the processing time can be significantly shortened.
In particular, even if a large number of golf carts 2 are moving within the golf course, the time required for each golf cart 2 to obtain its own correction data c does not change. As long as the difference data d is sent out at intervals, the position of the moving golf cart 2 can be relatively grasped.

That is, the GPS receiver of this embodiment is
In the fixed station 12 provided with 13, the difference data calculation means 23 for calculating the difference data d between the measured position of the fixed station 12 obtained from the GPS receiver 13 and the true coordinate position, and the difference data calculation means 23 The obtained difference data d is used for all golf carts 2.
While having a differential data transmission means 24 to collectively transmit to,
Each golf cart 2 equipped with a GPS receiver 3 has a fixed station 12
Difference data receiving means 33 for receiving the difference data d from the difference data transmitting means 24 and the difference data d received by the difference data receiving means 33
Since the golf cart position correcting means 36 for correcting the measured position obtained from the PS receiver 3 is provided, a large number of golf carts 2 can accurately grasp their own positions at short intervals.

Further, in each golf cart 2 of the present embodiment, the correction data transmitting means 35 for transmitting the positioning position corrected by the golf cart position correcting means 36 to the fixed station 12 as the correction data c.
And a correction data receiving means 34 capable of receiving the correction data c ′ transmitted from the correction data transmitting means 35 of another golf cart 2. Therefore, since each golf cart 2 can receive the correction data c ′ transmitted from the golf carts 2 in the vicinity, not only the accurate position of itself but also the accurate position of the golf carts 2 in the vicinity are grasped. It will be possible.

The present invention is not limited to the above embodiments, but various modifications can be made within the scope of the gist of the present invention. For example, in the embodiment, the apparatus for centrally managing 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 an S receiver.

[0029]

According to the GPS error correction apparatus of the present invention as set forth in claim 1, a fixed station installed at a known coordinate position is equipped with a fixed GPS receiver capable of receiving radio waves from an artificial satellite and is movable. Each of the plurality of mobile stations is equipped with a mobile GPS receiver capable of receiving radio waves from an artificial satellite, and the fixed station has a difference between a measured position of the fixed station obtained by the fixed GPS receiver and a true coordinate position. The mobile station further comprises difference data calculating means for calculating data, and difference data transmitting means for collectively transmitting the difference data obtained from the difference data calculating means to all the mobile stations, wherein each mobile station has a difference from the fixed station. Differential data receiving means for receiving differential data from the data transmitting means, and a positioning position obtained from the mobile GPS receiver of each mobile station based on the differential data received by the differential data receiving means Is constructed further comprises a position correction means for correcting, it is possible to accurately grasp its position in a number of mobile stations short intervals.

Further, the GPS error correction apparatus of the present invention according to claim 2 is different from correction data transmission means for transmitting the positioning position corrected by the position correction means to each fixed station to the fixed station by each mobile station. And a correction data receiving unit capable of receiving the correction data transmitted from the correction data transmitting unit of the mobile station.
In addition to the effect of the invention described in (1), it becomes possible to accurately grasp the position of another mobile station in the vicinity of itself.

[Brief description of 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]

 1 Artificial Satellite 2, 2a to 2z Golf Cart (Mobile Station) 3 GPS Receiver (Mobile GPS Receiver) 12 Fixed Station 13 GPS Receiver (Fixed GPS Receiver) 23 Difference Data Calculation Means 24 Difference Data Transmission Means 33 Difference Data Receiving means 34 Correction data receiving means 35 Correction data transmitting means 36 Golf cart position correcting means (position correcting means)

Claims (2)

[Claims] 1. A fixed station installed at a known coordinate position,
A fixed GPS receiver capable of receiving radio waves from an artificial satellite is provided, and a mobile GPS receiver capable of receiving radio waves from an artificial satellite is provided at each of a plurality of movable mobile stations, and the fixed station is the fixed station. Difference data calculation means for calculating difference data between a measured position of a fixed station and a true coordinate position obtained from a GPS receiver, and difference data obtained by this difference data calculation means are collectively transmitted to all the mobile stations. The mobile station further comprises a differential data transmitting means, each mobile station receives differential data from the differential data transmitting means of the fixed station, and each mobile station moves based on the differential data received by the differential data receiving means. A GPS error correction apparatus, further comprising: a position correction unit that corrects a positioning position obtained from the mobile GPS receiver of the station. 2. Each mobile station is transmitted from a correction data transmitting unit that transmits the measured position corrected by the position correcting unit to the fixed station as correction data, and from the correction data transmitting unit of another mobile station. The GPS error correction apparatus according to claim 1, further comprising a correction data receiving unit capable of receiving correction data.