JPS62276478A - Apparatus for measuring gps position - Google Patents

Abstract

PURPOSE:To select an optimum satellite even if the catching of a standard satellite becomes impossible, by catching the standard satellite necessary for positional measurement and preliminarily catching other receivable satellite in succession using a preparatory channel. CONSTITUTION:The optimum satellite selection part 17 of a central processing unit 14 selects a satellite combination minimizing a DOP value from receivable satellites on the radio wave from a satellite received by the antenna of a vehicle to allot the same to channels CH1-CH4. A three-dimensional position is calculated on the basis of the satellite data caught by the channels CH1-CH4. A preparatory satellite catching apparatus 15 confirms all of satellites not caught by the channels CH1-CH4 to store the same in a satellite data memory part 20. When satellite selection/combination is changed by the disappearance of satellites, optimum satellites are selected from the satellites registered in a receivable satellite registering part 22.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Industrial Field of Application]
ning3system).

[Prior Art] A GPS positioning device measures the position of an aircraft, ship, medium-sized body, or other positioning object by receiving radio waves from an artificial satellite for a plurality of satellites necessary for positioning. However, its principle, method, etc. are disclosed in Japanese Patent Application Laid-Open No. 1983-15.
573. Institute of Electronics and Communication Engineers Technical Research Report VO1, 84, positive 7
8.5ANE84-12. Automotive Technology 1985. V○L
, 39-1 (Satellite Navigation Global Positioning
System), etc.

By the way, conventional GPS position measuring devices create a combination of a predetermined number of If7 stars from among a large number of satellites orbiting in the sky above the object to be positioned, and select a predetermined combination of VtI stars (hereinafter, satellites with this combination are referred to as drifting satellites). It is configured to receive satellite radio waves from the satellite (called ``Subject'') and calculate the position of the object to be measured.

However, in the conventional GPS position measuring device as described above, terrain changes occur in accordance with the movement of the positioning object, so
During positioning, it was often impossible to receive the selected satellite, making it difficult to perform stable positioning.

Therefore, in the past, a reserve channel was provided, and this premix channel ↑・
One preliminary satellite that is not always used in the combination is assigned to the channel, and when one of the standard satellites is deleted, the reserve satellite is substituted.

However, with conventional GPS positioning devices that use these spare satellites, depending on the satellite that is erased, there are many cases in which donations that cannot perform highly accurate positioning or the spare satellite itself is erased, resulting in stable It was difficult to perform accurate positioning.

[Object of the invention] The present invention improves the above problems and allows stable positioning to continue even if one or more of the standard satellites is deleted.
The purpose of the present invention is to provide a GPS position measuring device that can be used in conjunction with a smartphone.

[Summary of the Invention] In order to achieve the above object, the present invention provides a GPS position measuring device with a standard satellite acquisition means that acquires the number of standard satellites required for positioning, and a standard satellite acquisition means that acquires the remaining visible satellites sequentially and acquires the latest acquisition. Preliminary satellite acquisition means for storing information, the standard satellite acquisition means, and the preliminary satellite acquisition means select satellites that are most suitable for positioning calculations from among these satellites, and select the selected satellites as described above. Optimum satellite selection means to be assigned to each channel of the standard satellite acquisition means; the preliminary satellite acquisition means searches for receivable satellites from visible W1 stars, and the optimal satellite selection device searches for receivable satellites. By selecting the optimal satellite,
Even if the standard satellite is deleted, a new optimal satellite can be selected immediately.

[Example] Hereinafter, the present invention will be described in detail using the accompanying drawings.

Fig. 1 is a block diagram of a GPS position measuring device for a vehicle according to an embodiment of the present invention, Fig. 2 is a block diagram showing details of a central processing unit and preliminary satellite acquisition means, and Fig. 3 is a block diagram of a GPS position measuring device for a vehicle according to an embodiment of the present invention. FIGS. 4 and 5 are flowcharts showing JR essentials of processing by the preliminary satellite acquisition device, and FIG. 6 is a timing chart showing the satellite acquisition status of each channel.

In FIG. 1, 1 is an antenna, 2 is a high frequency amplifier, and 3
．． 5.6 is a mixer, 4 is a first intermediate frequency amplifier, 7 is a second
intermediate frequency amplifier, 8 a phase detector, 9 a numerically controlled oscillator for carrier phase synchronization, 10 a code generator, 11 a numerically controlled oscillator for code phase synchronization, 12 a frequency multiplier, 13
14 is a reference oscillator, 14 is a central processing unit, and 15 is a preliminary satellite acquisition device.

The configuration of channels CHI to CH4 is the 5th channel CH
It is the same as 5.

Each channel CH1 to CH5 captures a predetermined IQj star at a predetermined timing based on a command from the central processing unit 15 or the preliminary satellite acquisition device 15, and transmits satellite data about the captured satellite to the central processing unit 14 or the preliminary satellite acquisition device. Provided on 15th.

As shown in FIG. F2, the central processing unit 14 includes a position calculation section 16 and an optimal satellite selection section 17.

The position calculation unit 16 operates on the first to fourth channels CH1 to CH
This method calculates the three-dimensional position xyz of the vehicle based on the satellite data for 4 satellites captured in 4.

(G) Each satellite selection unit 17 selects DO from among the receivable satellites.
P (D il+)tion of P
(recision) Select the satellite combination with the minimum I directness, and assign the selected satellites to each channel CH1 to CH4.
At the same time, when changing the satellite combination due to a change in time or when a satellite disappears, a signal @S1 indicating the content of the change is output to the preliminary satellite acquisition device 15.

The preliminary satellite acquisition device 15 includes a preliminary satellite recognition section 18, a satellite locking section 19, a satellite data storage section 20, a synchronization timing storage section 21, and a receivable satellite registration section 22. ing.

The preliminary satellite recognition unit 18 is connected to the optimum satellite selection unit 17 and selects four channels CI-11 to CI-C among the visible satellites.
1 (It recognizes all satellites that are not captured in step 4. Here, visible satellites mean all satellites that are placed on the earth's horizon relative to the vehicle position, and those that are hidden behind buildings or mountains. This includes satellites that are in a state of
By knowing the orbital data of the satellite, it can be uniquely determined as a function of time and vehicle position.

One satellite switching unit outputs a capture command signal S2 to the fifth channel HC5 to capture the satellites recognized by the preliminary satellite recognition unit 18 one by one in a time-division manner. That is, referring to Figure 3, visible satellites are #1 to #
Assume that there are seven satellites up to #7, and in this inner box channels 1 to 4, there are four satellites #1. #3. #4. Assuming that #7 has been captured, the preliminary satellite recognition unit 18 determines that there are t! [i star #2
．． #5° #6, the satellite switching unit 1 transfers these satellites #2 to the fifth channel CH5. #5. A capture command signal @S2 is output to sequentially capture #6.

The satellite data storage unit 20 stores satellite data for each satellite captured by the fifth channel CH5.

The synchronization timing storage section 21 stores the synchronization timing for a satellite newly incorporated into the preliminary satellite recognition section 18 so that the satellite can be captured immediately when the most MyfI star selection section 17 changes the optimal combination. .

The receivable satellite registration unit 22 registers satellites that can actually be received at present on the fifth channel CH5 among the satellites recognized by the preliminary satellite recognition unit 18.

As shown in FIG. 4, when the GPS position measuring device is turned on in step 401, the preliminary satellite acquisition device 15 starts the following process by a timer interrupt shown in step 402.

Step 405 shows the process of determining the input content of the signal S1 from the optimal satellite selection section 17.

Here, if the signal S1 is to switch the lost satellite to a substitute satellite based on the disappearance of rain, the process moves to step 406, and if it is to change the optimal satellite, the process moves to step 408.

Step 406 centrally processes the data of the substitute satellite.
Step 407 is to incorporate the lost satellite into the search satellite as a preliminary star. Further, step 408 is to output the data of the newly adopted satellite to the central processing unit 14, and step 409 is to output the data of the newly adopted satellite to the central processing unit 14.
The satellites that were canceled due to the reclassification changes will be incorporated into the exploration satellites. Step 406 or Step 408
The number of substitute satellites or adopted satellites shown in is not limited to a single number, but may be multiple.

In addition, the preliminary satellite acquisition device 15, as shown in FIG.
Processing is underway to search for kitten satellites that can be received.

In step 501, the preliminary satellite recognition unit 18 selects the satellite switching unit 1.
9 shows the process of setting the satellite to receive data.

Step 502 indicates processing of synchronization timing of the satellite switching unit 19. One satellite switching unit outputs a capture command signal S2 to capture a predetermined satellite based on the same January timing for the predetermined satellite stored in the synchronization timing storage unit 21.

Step 503 is a command signal S2 from one satellite switching unit.
This shows a process of determining whether or not the satellite radio wave of the satellite has been received on the fifth channel CH5 based on the 5th channel CH5. If so, proceed to step 50.
Skip moving to 8.

Step 504 is to determine whether or not the desired data has already been collected for the (I star). If the desired data has already been collected, the process moves to step 505, and if it has not been collected yet, the process moves to step 505. This shows the process of moving the process to step 507.

In step 507, data collection processing is performed.

Step 505 shows the process of storing the synchronization timing of A for the received satellite in the synchronization timing storage section 21.

In step 506, the satellite number of the satellite capable of receiving 3 is received. ! This shows the process of currently recording data into the recording section 22.

On the other hand, step 508 shows a process in which the satellite number of the relevant satellite is canceled from the receivable satellite registration unit 22 in order to correct the fact that reception was determined to be unreceivable in step 503.

As described above, through the processing shown in FIGS. 4 and 5, receivable satellites are always registered in the receivable satellite n green section 22,
Central location I! I! The headpiece 17 can refer to this registered content and select R suitable (nj stars) among satellites with a high capture probability.

Figure 6 shows 1! of each channel! This shows the acquisition status of Star J.

In the figure, the numbers 1 to 7 indicate the r7 star numbers, the circles indicate the states in which each channel is capturing the satellite, and the tick marks indicate the states in which each channel was unable to capture the satellite.

First, at time to, the optimal VFI star selection device 17 selects satellites #1, #3,... in the satellite arrangement shown in FIG.
#4. Assume that #7 is selected as the optimal satellite. The position calculation unit 16 of the central processing unit 14 calculates the four satellites #1. #3. The position of the vehicle is calculated using #4 and #7. At this time, the preliminary satellite recognition unit 18
Remaining visible satellites #2゜#5. Set #6 as a backup satellite,'
The ffI star switching unit 19 selects #2. #5. Sequentially connect the satellites in the order of #6, and in the fifth channel CH5, each satellite #2. #
5. #6 is captured sequentially.

Therefore, as shown in FIG. 6(e), at time t1, the receivable satellite registration unit 22 has #2. #5 and #6 satellites are registered as receivable satellites.

Next, assume that at time t1, satellite #7, which was being captured by the fourth channel CH4, is hidden by, for example, a building and cannot be captured. In order to calculate the position of the vehicle, the optimal satellite selection unit 17 calculates the DOP value and selects satellite #6 as a substitute for the lost satellite among the 'EI stars registered in the receivable satellite registration unit 22. Select the most suitable satellite #
1. #3゜#4. #6, and inform the preliminary satellite recognition unit 18 of the ex-husband satellite number #7 and the substitute satellite number #6 by sending @s1.

The preliminary satellite recognition unit 18 identifies the search satellite as 62. based on the signal s1. #5. #6! 2. #5. #7, and the satellite switching unit 19 outputs a satellite switching signal s2 to the fifth channel CH5 to sequentially acquire the changed satellites.

Therefore, at time t3, if the receivable satellite registration unit 22 receives the #7 satellite again, the optimal satellite selection unit 17 selects the #1. #3. #4. #1 from satellite combination #6
．． #3. #4. Considering that satellite combination #7 is more optimal, the optimal satellite combination will be selected from #1. #3. #4. This is combination #7.

In this case, the preliminary satellite acquisition device 15 detects the remaining satellites #2 and #5.
．． Search for #6.

At time t5, the first. Second. 3'#I star #1 was captured on the 4th channel. Assume that #3° and #7 cannot be captured at the same time. In this case, the optimal satellite selection unit 17 selects the optimal satellite combination #2 from among the remaining satellites.
#4. #5. #6 is created, and the position calculation unit 16 performs a predetermined position calculation using this satellite combination.

Time jy, r8. As shown in jg, the optimal satellite selection unit 1
7 sequentially changes the optimal combination of satellites when receivable satellites appear in the receivable satellite record section 22, and the position calculation section 1
6 performs a predetermined position calculation based on the combination.

As mentioned above, the GPS position measurement device shown in this example is
The fifth channel CH5 can always search for satellites that can be received, and the optimal satellite selection section 17 can select the optimal satellite from among the receivable satellites, so the position calculation section 16 becomes unable to perform calculations. Or, the chances of performing calculations on a satellite with a defective DOP are reduced, and it becomes difficult to constantly perform high-accuracy position calculations.

In addition, in this example, a satellite data storage section 20 is installed in the preliminary satellite annotation device 15 so that satellite data can be stored. Data can be provided and calculation speed can be increased.

Furthermore, in this example, since the predictive satellite acquisition device 15 is provided with a synchronization timing storage section 21 for each satellite, each channel CH1
~The work of satellite acquisition in CH5 can be facilitated.

In addition, in the above embodiment, an example was given in which three-dimensional positioning is performed using the central processing unit 14, and an example was shown in which four satellites are always captured using four channels CH1 to CI- (4). Of course, it is possible to perform positioning and height measurement.

[Effects of the Invention] As described above, according to the present invention, it is possible to search for receivable satellites using the spare channel and provide the search results to the optimum satellite selection means, so that the position calculation means can search for receivable satellites. By using the optimum satellite, position calculation means can be performed more reliably and with higher precision.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a GPS position measuring device for a vehicle according to an embodiment of the present invention, Fig. 2 is a block diagram showing details of a central processing unit and a preliminary satellite acquisition device, and Fig. 3 is a block diagram of a GPS position measuring device for a vehicle according to an embodiment of the present invention. FIGS. 4 and 5 are flowcharts showing an outline of the processing of the preliminary satellite acquisition device, and FIG. 6 is a timing chart showing the satellite acquisition status of each channel. 14...Central processing unit 15...Backup satellite acquisition device 16...Position calculation unit 17...Optimum satellite selection unit 18...Backup satellite recognition unit 19...Satellite switching unit 20...Satellite Data storage unit 21...Synchronization timing storage unit 22...Receivable satellite registration unit Patent applicant Nissan Motor Co., Ltd. Figure 1 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] A standard satellite acquisition means that acquires the number of standard satellites necessary for positioning, a preliminary satellite acquisition means that sequentially acquires the remaining visible satellites and stores the latest acquisition information, and the standard satellite acquisition means and the preliminary satellite acquisition means GPS positioning comprising: optimum satellite selection means for selecting the optimum satellite for positioning calculation from among the captured satellites and assigning the selected satellite to each channel of the standard satellite acquisition means; Measuring device.