JPH0415586A - Gps receiver - Google Patents

Abstract

PURPOSE:To hold a satisfactory receiving state even when a satellite is obstructed by an obstacle by providing plural pieces of antennas, switching and controlling an antenna switching means, and selecting the antenna whose number of receivable satellites is maximum. CONSTITUTION:Plural antennas 1A, 1B are installed in positions separated to the utmost. When reception of a GPS satellite is started, a control part 5 controls an antenna switch 2, selects alternately the antennas 1A, 1B, sends receiving radio waves of the respective antennas to an RF receiving part 3 and a signal processing part 4, and derives the number of receivable satellites of the respective antennas. Subsequently, the control part 5 compares the obtained satellite numbers. When the antenna 1A (1B) is larger in the number of receivable satellites, the switch 2 is switched to the antenna 1A (1B) side, and reception of the satellite is executed by using the antenna 1A (1B). The control part 5 executes repeatedly the processing at every prescribed interval. As a result, even if the satellite whose position is being measured is obstructed by a building, etc., and becomes unreceivable, the position measurement can be continued by using other receivable satellite.

Description

[Detailed Description of the Invention] (Field of Application of Industry-1-) The present invention is a positioning system using an artificial satellite.
S (GIobi+I Positioning Sy
The present invention relates to a GPS receiver that performs measurements using 7 stems.

[To perform positioning using conventional technology IGPS, 14 low;) pieces;
Preferably, two or four C, I'S satellites are required (Iζ); 11. The 11 GPS receivers are equipped with one seven-channel receiver and are capable of sequentially receiving a desired number of satellites, which is more than the number required for positioning.

[Problem to be solved by the invention]

However, as in the past, one antenna can handle multiple G
r) When receiving S satellites, the satellites were sometimes blocked by hills, etc., and sometimes it was not possible to receive the specified number of satellites required for positioning. Such problems arise when using an in-vehicle GP that involves movement of the vehicle.
This is particularly noticeable in S receivers.

The present invention was made to solve the above problems, and
The objective is to provide a GPS receiver that can maintain as good reception as possible even when the satellites are blocked by obstacles.

[Failure to solve the problem]

In order to achieve the above object, a first invention provides a GPS receiver with a one-channel configuration, comprising: a plurality of antennas; an antenna switching means for switching and selecting the plurality of antennas;
and means for controlling the switching of the antenna switching means to select the antenna that can receive the maximum number of satellites.

Further, a second invention provides a GPS receiver having a one-channel configuration, including a plurality of antennas, an antenna switching means for switching and selecting the plurality of antennas, and a method in which all the antennas are arranged to be less than or equal to a predetermined minimum number of reception satellites. When only one satellite can be received, a predetermined number of satellites suitable for positioning are selected from among all the satellites that can be received by each antenna, and the antenna switching means is switched and controlled to switch the antenna corresponding to the selected satellite. and means for sequentially selecting.

[For production]

In the case of the first invention, satellite reception is performed using the antenna with the best reception condition among the plurality of antennas. Therefore, more satellites can be received, and even if some satellites are blocked by buildings, positioning can be continued using other receiving satellites.

In the case of the second invention, when the number of receiving satellites for all antennas falls below a predetermined minimum number of receiving satellites, a predetermined number of satellites suitable for positioning are selected from among all the satellites that can be received by each antenna. and receive it.

Therefore, even if a reception state occurs in which positioning is not possible with each individual antenna, positioning can be continued using the receiving satellites of all the antennas.

Note that the conditions for selecting satellites in the second invention include, for example, selecting a combination of satellites with the smallest PDOP (geometric deterioration coefficient), or selecting the required number of satellites in order of the received signal strength. good.

〔Example〕

Hereinafter, the present invention will be explained in detail by taking the case of a vehicle-mounted GPS receiver as an example.

FIG. 1 shows an example of the configuration of an on-vehicle OPS receiver configured to apply the present invention. In the figure, IA and IB are two independently arranged antennas, 2 is an antenna switcher that freely switches between these two antennas, 3 is an RF receiving unit that despreads the received satellite radio waves and sequentially receives the target satellite; 4 is a signal processing unit that positions the current location from the navigation data of the receiving satellite, and 5 is a control unit. In addition, two antennas IA, I
As shown in FIG. 2, for example, it is desirable to install B at positions as far apart as possible, such as the front and rear sides of the vehicle.

Proceeding, the operation of the first embodiment of the present invention will be explained as shown in FIG.
- Explain with reference to the chart.

When GPS satellite reception starts (step 531),
The control unit 5 controls the antenna switching device 2 to select the antennas IA,
IB is selected alternately, and the received radio waves of each antenna are sent to the RF receiving section 3 and signal processing section 4, and the antennas LA, I
For B, the number of satellites that can be received by each antenna is determined (steps S32, 533). Then, the control unit 5 compares the obtained number of satellites that can be received by the antennas IA and IB (step 534).

If the number of satellites that can be received by antenna IA is larger than that of antenna IA, switch antenna switch 2 to antenna switch
Satellite reception is performed using A (step 535). On the other hand, if the number of satellites that can be received by antenna IB is greater than that by antenna IB, antenna switching device 2 is switched to the antenna switching device, and satellite reception is performed using antenna 1B (step 336).

The control unit 5 repeatedly executes the process at predetermined intervals.
. As a result of ,-, two ? Reception is performed using the 7th channel on the side with the largest number of satellites that can be received by A, IB, etc., and if the satellite in the measurement (i'f) is blocked by a building Even if reception becomes impossible, you can use other satellites that can receive
Positioning can be continued using

FIG. 4 shows a flowchart of the operation of the second embodiment of the present invention. Note that the configuration of the GPS receiver itself is the same as that shown in FIG.

In the case of this second embodiment, two un-J-IAs.

The minimum number of reception satellites (for example, 5) serving as a determination threshold for each antenna 4TJ't is set in advance in IB, and is used for the determination processing in steps S4/I and subsequent steps in FIG.

G l) When reception of the S satellite starts (step 54
1) The control unit 5 controls the antenna switch 2 to alternately select the antennas LA and IB, sends the received radio waves of each antenna to the RF receiver 3 and the signal processing unit 4, and selects the antenna I.
The number of satellites that can be received by each antenna is determined for A, IB (steps S42, 543). Then, the control unit 5 calculates the number of satellites that can be received by the obtained antennas IA and IB.
i! , WE low fi, L, Lib person A iJ#'
(Step 544).

If the force of antenna 1△, II3 (P+possible force 11!) is equal to or greater than the minimum number of force of antenna 1△, II3 (P+possible force 11!), the process moves to step S45, and the force of antenna 1Δ or IB is determined. Receiving (,'; Determine whether the number of r-i1 satellites is hot or not, and perform reception of the antenna satellite with the larger number of receivable satellites (steps 346, 47).

- On the other hand, in Swoop S44, antenna 1Δ.

If the minimum number of receiving satellites for both antennas is not 1-, the process moves to step 348, and it is determined whether the minimum number of receiving satellites for both antennas is 1-. and,
If only one of the antennas has the minimum number of receiving satellites or less, the process moves to step S49, where it is determined which antenna has the minimum number of receiving satellites or more, and The satellite is received using the antenna (step S 50 + 5 ).

Further, if it is determined in step S48 that both antennas 1Δ and IB are equal to or less than the minimum number of receiving satellites, the process moves to step S52. Then, a predetermined number of satellites suitable for positioning at that time are selected from among all the satellites that can be received by the two antennas IA and IB.

As mentioned above, the conditions for selecting satellites include, for example, selecting a combination of satellites with the smallest PDOP (XJ mathematical precision deterioration coefficient), or selecting a predetermined number of satellites in descending order of received signal strength. good.

When a predetermined number of satellites are selected in step S52 as described above, the control unit 5 adaptively switches and controls the antenna switching device 2 in accordance with the selection, and uses both antennas lΔ and IB to select the selected plurality of satellites. satellites sequentially.

The control unit 5 repeatedly executes the process at predetermined intervals.

As a result, if either of the two antennas can only receive satellites that are less than the predetermined minimum number of reception satellites, a predetermined number of satellites suitable for positioning at that time will be selected from among all the satellites that can be received by antennas LA and IB. is selected and reception is performed. Therefore, even if the satellite in i'1llll (☆) is blocked by a hill or the like and cannot be received, positioning can be continued using other receivable satellites.

Note that 1); Embodiment B of Section I: The case where a 12-wood antenna is used is taken as an example, but 2 wood antennas 1- may be installed.
L Of course. In addition, the minimum number of reception ITs for the determination in the second embodiment may be set to be different for each anti-no, or may be set to be the same for all antennas. Which one to adopt is cis-0J-1, No.1
You can decide according to your needs.

[Effects of the Invention] As is clear from the above description, according to the 10th invention, the antenna with the largest number of receivable satellites is selected from among the antinos of the number of bands to receive the satellite. According to the second invention, a predetermined number of satellites suitable for positioning are selected from among all the satellites that can be received by each antenna. l
7, so Mamoru JII who was positioning was interrupted by 1
・Even if reception becomes impossible at 1°, positioning can be continued using other receiving satellites, and positioning can be prevented from being interrupted.Furthermore, by using multiple antennas, By carefully arranging the location of the antenna for reception, it is possible to cover the entire range, and this is particularly effective for mobile GPS receivers and the like.

[Brief explanation of the drawing]

Figure 1 shows a GPS system configured by applying the present invention.
A block diagram of one embodiment of the receiver, FIG. 2 is a diagram showing an example of antenna installation, and FIG. 3 is a flowchart 1 of the operation of the first embodiment of the present invention.
・, FIG. 4 is a flowchart 1 of the operation of the second embodiment of the present invention.
− is. lA, ]B... Antenna ', 2... Antenna switcher, 3... RF receiving section, 4... Signal processing section, 5...
control section.

Claims (2)

[Claims] (1) In a GPS receiver with a one-channel configuration, a plurality of antennas, an antenna switching means for switching and selecting the plurality of antennas, and an antenna that can receive the maximum number of satellites by switching and controlling the antenna switching means. A GPS receiver characterized by comprising: means for selecting. (2) A GPS receiver with a one-channel configuration includes multiple antennas, an antenna switching means for switching and selecting the multiple antennas, and a system in which all antennas can only receive satellites that are less than or equal to a predetermined minimum number of reception satellites. means for selecting a predetermined number of satellites suitable for positioning from among all the satellites that can be received by each antenna, and controlling the antenna switching means to sequentially select antennas corresponding to the selected satellites; A GPS receiver characterized by: