JPH03295411A - Satellite display system in on-vehicle navigation device - Google Patents

Abstract

PURPOSE:To confirm a receivable satellite on a display part by displaying the position of the receivable artificial satellite on the display part according to position data and current position data. CONSTITUTION:The satellite S is acquired first to gather navigation data, from which the number of the receivable satellite is found and stored in a RAM 7. Then receivable satellites S are acquired in order to gather navigation data and a satellite S is selected in consideration of the reception intensity of the signal and the coefficient of position measurement deterioration of the satellite S used for position measurement to start measuring the position, thereby obtaining the current position data on this system. Then position data on the respective receivable satellites S are found to find the azimuth angles and elevation angles of the respective satellites S and the positions of the respective satellites S are displayed on the display part 12 together with the satellite numbers to confirm the number of the receivable satellites S and the satellite numbers.

Description

[Detailed description of the invention] [Industrial application field] This invention is based on GPS (Global Position
The present invention relates to a method for displaying artificial satellites in a vehicle navigation device using a receiver, which displays receivable artificial satellites (GPS satellites) on a display unit.

[Conventional technology]

GPS in its initial state without navigation data from satellites (ephemeris data, almanac data, etc.)
By capturing the artificial satellites and receiving navigation data, the receiver can determine where each artificial satellite is located based on the almanac data.

Therefore, each receivable artificial satellite is captured, and the reception strength of the signal from each artificial satellite and the positioning deterioration coefficient (the smaller the positioning deterioration coefficient, the more reliable the positioning result is) by the three or four artificial satellites used for positioning. Select an artificial satellite and start positioning.

Note that if navigation data has been previously collected, the position of each satellite can be determined based on that almanac data.

However, conventionally, receivable satellites are not displayed on the display, so in order to check the receivable satellites, the sixth This was confirmed based on the satellite's elevation angle characteristic diagram as shown in the figure.

In FIG. 6, dotted lines indicate the locus of the elevation angle of each satellite, and numerical values indicate each satellite number.

The elevation angle characteristic diagram in Figure 6 is 139 degrees east longitude, 3 north latitude
5 degrees and at an altitude of Om.

(Problems to be Solved by the Invention) Conventional vehicle navigation devices do not display on the display the artificial satellites that can be received, that is, those located above the horizon, so even if positioning is started, positioning cannot be performed. However, there was an inconvenience in that it was not possible to determine why positioning was not possible, that is, whether positioning was not possible due to a lack of receivable satellites, or whether positioning was not possible due to obstacles such as buildings.

Furthermore, even if it is possible to confirm receivable satellites using the elevation characteristic diagram shown in Figure 6, there is the inconvenience that it is not possible to know in which direction the receivable satellites are located. Ta.

This invention was made in order to eliminate the above-mentioned inconveniences. By looking at the display, it is possible to know the number of satellites that can be received and their positions, as well as the location of the satellites used for positioning. The purpose of the present invention is to provide a method for displaying artificial satellites in a vehicle navigation device that allows the user to confirm the following information.

[Means for Solving the Problems] A display method for artificial satellites in a vehicle navigation device according to the present invention calculates the position data of each artificial satellite and its own current position data based on navigation data received from the artificial satellites, The orthogonal coordinate axes are north, south, east and west, and the origin is an elevation angle of 90 degrees.The elevation angle is expressed by concentric circles centered on the origin, and the position of the satellite that can be received is determined by corresponding to a shape in which the angle of elevation decreases as it moves away from the origin. The information is displayed on the display unit based on the data and current position data.

Further, in a display method of an artificial satellite in a vehicle navigation device according to another invention, a line connects the display position of the artificial satellite used for positioning and the origin.

Furthermore, in the display method of the artificial satellite in the vehicle navigation device according to another invention, the display form for displaying the display position of the artificial satellite used for positioning is changed from the display form for displaying the display position of another artificial satellite. It makes a difference.

Furthermore, a method for displaying artificial satellites in a vehicle navigation device according to another aspect of the invention also displays the trajectory of artificial satellites that can be received from the current time until a predetermined time later.

Furthermore, in the display method of the artificial satellite in the vehicle navigation device according to another invention, a number is also displayed on the artificial satellite.

(Function) The artificial satellite display method in the vehicle navigation device according to the present invention obtains the position data of the artificial satellite and its own current position data based on the navigation data received from the artificial satellite.

Then, the orthogonal coordinate axes are north, east, west, and south, and the origin is at an elevation angle of 9
0 degrees, and the elevation angle is represented by concentric circles centered on the origin, and the positions of receivable satellites are displayed based on the above-mentioned position data and current position data, corresponding to a shape in which the elevation angle decreases as the distance from the origin increases. displayed in the section.

In addition, the display position of the artificial satellite used for positioning may be displayed by connecting the origin with a line, or the display position of the artificial satellite used for positioning may be changed to the display position of other artificial satellites. It displays the display in a different display format, displays the trajectory of satellites that can be received within a predetermined period of time from the current time, and displays the satellite number.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a vehicle navigation device according to an embodiment of the present invention, where S is an artificial satellite, 1 is an antenna for receiving navigation data (signal) from the artificial satellite S, and 2 is a diagram showing the configuration of a vehicle navigation device according to an embodiment of the present invention. This analog section 2 amplifies the signal transmitted through the antenna 1, and also performs processing to lower the frequency of the received signal to a frequency that can be digitally processed.

3 is a digital signal processor signal processing section (DSP signal processing section) that despreads and demodulates the output of analog section 2, and 4 is equipped with a numeric keypad, function key touch panel, etc. for inputting necessary data, etc. The operation section is shown.

Reference numeral 5 indicates a CPU, which executes a system program stored in the ROM 6 using the outputs of the DSP signal processing unit 3 and the operation unit 4, and the data in the RAM 7.
The RAM 7 is used as a work area to realize various necessary functions.

The vehicle navigation device is controlled by a microcomputer composed of CPU5 to RAM7.

Note that the RAM 7 stores important data such as almanac data.

Reference numeral 8 denotes a clock section composed of an integrated circuit, and 9 indicates a battery. This battery 9 is for backing up the RAM 7 and the clock section 8.

10 is an interface section, 11 is a system bus,
Three DSP signal processing sections are connected to this system bus 11.

Reference numeral 12 denotes a display section connected to the interface section 10, which displays various information.

Although only one artificial satellite S is shown, a plurality of artificial satellites can be received.

FIG. 2 is a flowchart for explaining the operation according to the present invention, and STI to ST5 indicate each step.

FIG. 3 is an explanatory diagram showing an example of the display on the display unit 12,
The origin represents the current position (positioning point) and the elevation angle of 90 degrees,
Concentric circles centered on the origin represent elevation angles of 60 degrees, 30 degrees, and 0 degrees from the inside, and the numbers represent the satellite numbers.

Note that the displayed position of the artificial satellite is the current position.

Next, the operation will be explained.

First, when the power is turned on, an artificial satellite S is captured to perform initial settings for positioning, navigation data is collected, and almanac data is stored in the RAM 7 (step 5TI).

Then, based on the collected almanac data, the number of healthy satellites and receivable satellite numbers are determined and stored in the RAM.
7 (step 5T2).

Next, the receivable satellites S are captured sequentially to collect navigation data, and the signal reception strength and the 3
Select an artificial satellite S by considering the positioning deterioration coefficient (the smaller the positioning deterioration coefficient, the more reliable the positioning result is) by the three or four artificial satellites S, start positioning, and use its own current position data ( longitude, latitude, altitude) and collect time data (step 5T3).

Then, position data (azimuth data,
(elevation angle data, etc.) (step 5T4).

Next, the azimuth and elevation angle of each artificial satellite S are determined based on the current position data obtained in step ST3 and the position data of each artificial satellite S obtained in step ST4, and the azimuth and elevation angle of each artificial satellite S are determined along with the artificial satellite number. After displaying the position on the display unit 12 (step 5T5), the process proceeds to step ST3.

When the positions of the artificial satellites S are determined in this manner and displayed on the display unit 12, the positions of each artificial satellite S can be displayed as shown in FIG.

Therefore, by looking at the display unit 12, the number of receivable satellites S and the satellite number can be easily confirmed.

In addition, by looking at the display unit 12, if there are enough satellites S but positioning is not possible, you can easily determine which position to move to to enable positioning by checking the surrounding situation. can be judged.

FIG. 4 is an explanatory diagram showing another example of the display on the display unit 12, and the straight line connecting the origin and the display position of the artificial satellite S represents the artificial satellite used for positioning.

Note that the displayed figures are the same as in FIG. 3.

Next, the operation will be explained.

In step ST5 of FIG. 2, the display position of the artificial satellite MS used for positioning and the current position are connected with a straight line and displayed on the display unit 12, so that each artificial satellite S is The location can be displayed.

Therefore, by looking at the display unit 12, it is possible to confirm which artificial satellite S is being used for positioning.

Further, if the artificial satellites S used for positioning are scattered, the positioning deterioration coefficient becomes small, so by looking at the display unit 12, the positioning accuracy can be visually confirmed.

In the embodiment shown in Fig. 4, the display form of the display position of the artificial satellite S used for positioning may be changed, for example, by changing the color, changing the lighting state to a blinking state, or changing the display shape, instead of a straight line. [Possibly another person] - The display form of the display position of the satellite S may be different from that of the display position of the satellite S.

FIG. 5 is an explanatory diagram showing still another example of the display on the display unit 12, in which dotted lines and the like represent the trajectory of the artificial satellite S from the current time to a predetermined time later.

Note that the displayed figures are the same as in FIG. 3.

The time indicated on the outside of the outermost circle is the time at which reception becomes possible or the time at which reception becomes impossible.

Next, the operation will be explained.

In step ST4 of FIG. 2, position data of the healthy artificial satellite S obtained in step ST2 is obtained.

Then, in step ST5 of FIG.
Based on the time data collected in T3, the position data of each artificial satellite S obtained in step ST4, and the orbit data of each artificial satellite S, calculate the position data of each artificial satellite S from the current time until, for example, 3 hours later, The position of each artificial satellite S is displayed on the display unit 12 along with the artificial satellite number, the time when reception becomes possible, and the time when reception becomes impossible.

When the positions of the artificial satellites S are determined and displayed on the display unit 12 in this way, the positions of each artificial satellite S can be displayed together with their future trajectories, as shown in FIG.

Therefore, by looking at the display unit 12, it is possible to easily check which artificial satellite S becomes unreceivable and which artificial satellite S becomes receivable, along with the time.

In the embodiment shown in FIG. 5, the trajectory of the artificial satellite S from the current time up to three hours later is displayed, but the time data in hours can also be input from the operation unit 4.

〔Effect of the invention〕

As described above, according to the present invention, the orthogonal coordinate axes are east, west, north, south, the origin is an elevation angle of 90 degrees, the elevation angle is expressed by concentric circles centered on the origin, and the elevation angle decreases as the distance from the origin increases. The position of the satellites that can be received is displayed on the display based on the position data of the satellites that can be received and the user's current position data, so it is easy to check the satellites that can be received by looking at the display. In addition, if the number of satellites is sufficient but positioning is not possible, it is possible to easily determine where to move to make positioning possible by checking the surrounding situation. There is an effect.

Further, according to other inventions, the display position of the artificial satellite used for positioning may be displayed by connecting the origin with a line, or the display position of the artificial satellite used for positioning may be displayed by other means. Since the displayed position of the artificial satellite is displayed in a different display format from the display format, you can check which artificial satellite is being used for positioning by looking at the display, and you can also visually check the positioning accuracy. It has the effect of being recognizable.

Furthermore, according to another invention, the trajectory of satellites that can be received from the current time until a predetermined time later is displayed. This has the effect that it is possible to easily check whether reception is possible.

According to still another invention, since the artificial satellite number is also displayed, there is an effect that the artificial satellite number can be confirmed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a vehicle navigation device according to an embodiment of the present invention, and FIG. 2 is a flowchart for explaining the operation of the portion according to the present invention. FIGS. 3 to 5 are explanatory diagrams showing display examples of the display section, and FIG. 6 is an elevation angle characteristic diagram of a conventional artificial satellite. DESCRIPTION OF SYMBOLS 1... Antenna, 2... Analog part, 3... Digital signal processor signal processing part, 4... Operation part, 5... CPU, 6... ROM, 7... RA
M, 8... Clock section, 9... Battery, 10... Interface section, 11 System bus, 12... Display section. Figure 1 Figure 2 h Figure Figure 2

Claims (5)

[Claims] (1) Determine the position data of each satellite and its own current position data based on the navigation data received from the satellite, set the orthogonal coordinate axes as north, south, east, and west, and set the origin as an elevation angle of 90 degrees, and create a concentric circle centered on the origin. In a vehicle navigation device, the position of a receivable artificial satellite is displayed on a display unit based on the position data and the current position data, in correspondence with a shape in which the angle of elevation is represented by , and the angle of elevation decreases as the distance from the origin increases. Satellite display method. (2) The artificial satellite display method in a vehicle navigation device according to claim (1), wherein a line connects the display position of the artificial satellite used for positioning and the origin. (3) The artificial satellite in the vehicle navigation device according to claim (1), wherein the display form for displaying the display position of the artificial satellite used for positioning is different from the display form for displaying the display position of other artificial satellites. Display method. (4) The method for displaying artificial satellites in a vehicle navigation device according to any one of claims (1) to (3), wherein trajectories of artificial satellites that can be received up to a predetermined time after the current time are also displayed. (5) An artificial satellite display method in a vehicle navigation device according to any one of claims (1) to (4), which also displays an artificial satellite number.