JP3278911B2 - GPS navigation system for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a GPS navigation system for a vehicle.

[0002]

2. Description of the Related Art An abnormal positioning (erroneous positioning) detecting method of GPS is disclosed in JP-A-3-72285 and JP-A-3-1086.
No. 09 publication. That is, abnormality determination is performed by comparing a reference position by a device such as a beacon or map matching with a position by GPS.

[0003]

However, in these methods, the presence or absence of the detected positioning abnormality can be determined only when the reference position is obtained by a device such as a beacon or map matching. That is, the beacon could only determine the presence or absence of an abnormality in positioning by GPS at a predetermined location where the device was installed. In map matching, it was only possible to determine the presence or absence of an abnormality in positioning by GPS at a specific location such as an intersection. That is, these methods could not always be checked.

Therefore, an object of the present invention is to always use a GPS
G for vehicles that can detect abnormal positioning (erroneous positioning)
An object of the present invention is to provide a PS navigation system.

[0005]

According to the present invention, as shown in FIG. 8, a receiver M1 provided in a vehicle and receiving signals from a plurality of GPS satellites, and a plurality of GPS satellites received by the receiver M1 are provided. Altitude detecting means M2 for detecting the altitude of the receiver M1 from a signal from the GPS receiver, information storage means M3 storing map information including altitude information, and signals from a plurality of GPS satellites received by the receiver M1. latitude and longitude of the receiver M1 by a map altitude detecting means M4 for calculating the altitude of the receiver M1 by said information storing means M3 in accordance with the latitude and longitude, detection I by the said receiver altitude detecting means M2
Altitude positioning accuracy area for the altitude of the receiver M1 obtained,
For advanced receivers M1 by the map altitude detecting means M4
It determines the presence or absence of overlap between the high accuracy region determine the constant unit M5
Wherein the determination means comprises:
If the altitude accuracy area does not overlap, it is determined that there is an abnormality
The main point is that

[0006] Also, prior SL-size constant means M5, after determining abnormality and repeats the subsequent abnormality determination operations including the receiving operation from a satellite receiver, which performs normal GPS navigation When no abnormality is It is preferred that

[0007]

In the information storage means M3, map information including altitude information is stored. And the map height detecting means M4
From the latitude and longitude of the receiver based on signals from a plurality of GPS satellites received by the receiver M1, the altitude of the receiver M1 is calculated by the information storage means M3 according to the latitude and longitude.
Also, determine constant means M5 is, I'm the receiver advanced detection means M2
The altitude positioning accuracy area with respect to the detected altitude of the receiver M1 and the altitude of the receiver M1 by the map altitude detecting means M4 .
To determine the presence or absence of overlap with the altitude accuracy area
When the positioning accuracy area and the altitude accuracy area do not overlap
Judge as abnormal. That is, since the map information including the altitude information is used, it is possible to determine the presence or absence of the abnormality of the positioning by the GPS even in a place other than the determined place (place).

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of a GPS navigation system for a vehicle. A receiver 1 is mounted on the vehicle, and the receiver 1
Radio waves of the PS satellites S1 to S4 are received. Further, the microcomputer 2 obtains the position of the vehicle from the signal from the receiver 1. The microcomputer 2 has a CRT as a display device.
3 is connected, and the CRT 3 is arranged on an instrument panel of the vehicle. Further, the microcomputer 2 has a CD-
The ROM 4 is connected, and the CD-ROM 4 stores map information including altitude information. The microcomputer 2 and the CD
-The ROM 4 is also mounted on the vehicle.

On the other hand, the operating state and orbit of the satellite are
It is monitored by some tracking control stations 5. That is, the tracking control station 5 receives the data from the artificial satellite, determines whether or not the orbit is shifted based on the data, and transmits the orbit correction data to the satellite if the orbit is shifted.

In the embodiment, the microcomputer 2 constitutes a receiver altitude detecting means, a map altitude detecting means, and a judging means.
The D-ROM 4 constitutes information storage means. next,
The operation of the thus configured GPS navigation system for a vehicle will be described. FIG. 2 illustrates a process (flow chart) executed by the microcomputer 2.

At step 100 of the microcomputer 2, four satellites are selected. This means that of the available satellites in view,
Four satellites with small PDOP values are selected.
Then, the microcomputer 2 collects data from the four satellites in step 101, and confirms in step 102 that the health data is not unhealthy, and then proceeds to step 103. That is, when a clock oscillation abnormality or the like occurs in the satellite, the health data is checked, and in such an unhealthy state, the process returns to step 100 and positioning and display described later are not performed. Therefore, the load on the CPU is reduced by using the health data.

In step 103, the microcomputer 2 measures the distance between each satellite and the receiver 1, and calculates the latitude and the latitude of the receiver 1.
Measure longitude and altitude. Then, the microcomputer 2 calculates the altitude of the receiver 1 from the CD-ROM 4 corresponding to the latitude and longitude from the latitude and longitude of the receiver 1 based on the signals from the plurality of GPS satellites received by the receiver 1 in step 104. . Further, the microcomputer 2 obtains a difference between the altitude obtained from the reception signal of the receiver 1 and the altitude of the receiver 1 by the CD-ROM 4, and determines whether or not the difference is within a predetermined value. If the difference is within the predetermined value, the microcomputer 2 displays the current position on the CRT 3 in step 105.

The processing in step 104 will be described in more detail. As shown in FIG. 3, abnormalities are determined depending on whether or not the high-accuracy positioning area L1 of the GPS and the high-accuracy area L2 of the map information from the CD-ROM 4 overlap. Is determined. For example, at the points P1, P2, and P3 in FIG. 3, the regions L1 and L2 overlap and are normal. In this case, as shown in FIG.
The display of the current position is performed.

In the abnormal positioning determination processing in step 104, in addition to the above-described method, for example, as shown in FIG. 3, the altitude P1 by GPS and the altitude M1 using map information are directly determined. The difference Δ (= | P1−M
1 |) may be compared with a predetermined value.

On the other hand, in FIG. 2, the microcomputer 2 determines in step 104 the altitude obtained from the received signal of the receiver 1 and the CD-
If the difference between the altitude of the receiver 1 and the ROM 4 is out of the allowable range (for example, point P4 in FIG. 3), step 10 is executed.
Return to 1. That is, if the orbit of the artificial satellite is shifted and the data from the artificial satellite is incorrect, the difference between the altitude obtained from the received signal of the receiver 1 and the altitude of the receiver 1 by the CD-ROM 4 is out of the allowable range. Come off. Then, as long as there is an abnormality, steps 101 → 102 → 103 → 104 → 101
repeat. Therefore, in this case, as shown in FIG.
The current position is not displayed by the cursor C on the screen of the CRT 3.

In this state, the tracking control station 5 sends the orbit correction data to the satellite, and when the correct data is transmitted from the artificial satellite, the process proceeds from step 104 to step 105 to display the current position by the cursor C on the screen of the CRT 3. It is displayed (for example, point P5 in FIG. 3).

As described above, in this embodiment, the CD-ROM 4 (information storage means) in which map information including altitude information is stored is provided, and the microcomputer 2 (receiver altitude detecting means, map altitude detecting means, abnormality determination) Means) detects the altitude of the receiver 1 from the signals from the plurality of GPS satellites S1 to S4 received by the receiver 1, and further detects the plurality of GPS
From the latitude / longitude of the receiver 1 based on the signals from the satellites S1 to S4, the altitude of the receiver 1 by the CD-ROM 4 corresponding to the latitude / longitude is calculated, and the receiver 1 based on the data from the satellites S1 to S4. Between the altitude of the receiver 1 and the altitude of the receiver 1 by the CD-ROM 4, and when the amount of the deviation deviates from an allowable value, it is determined that there is an abnormality.

As a result, Japanese Patent Laid-Open Publication No. 3-72285 and Japanese Patent Laid-Open Publication No. 3-1086 disclose a GPS abnormal positioning detecting method.
However, in these publications, it was only possible to determine the presence or absence of the detected positioning abnormality only when the reference position was obtained by a device such as a beacon or map matching. However, according to the present embodiment, since the map information including the altitude information is used, it is possible to determine the presence or absence of the abnormality of the positioning by the GPS even at a place other than the determined place (place). As a result, it is possible to always detect abnormal positioning (erroneous positioning) of the GPS. In addition, the abnormal positioning of the GPS (erroneous positioning) can be adapted when the data transmitted from the satellite is erroneous, and various measures can be taken even when the erroneous data from the satellite is transmitted to the receiver. Become.

After determining that there is an abnormality, the microcomputer 2 repeats the subsequent abnormality determination operation including the reception operation of the receiver 1 from the satellite (steps 104 to 101 in FIG. 2). Perform GPS navigation. That is,
JP-A-63-663 discloses a conventional technique for eliminating abnormal measurement values.
478 and JP-A-3-108681. These do not output the measured value when the position is determined to be an abnormal measurement position, but no action can be taken when the abnormality is removed. However, in this embodiment, when the cause of the abnormality has disappeared, normal positioning can be promptly performed by demodulating the satellite data.

The present invention is not limited to the above-described embodiment. For example, the microcomputer 2 includes a receiving operation from a satellite of a receiver not only at the time of detecting an abnormal altitude but also at the time of various abnormalities. The subsequent abnormality detection operation may be repeated, and the normal GPS navigation (return to step 101 in FIG. 2) may be executed when the abnormality disappears.

Further, without using the CD-ROM 4 of FIG.
In addition, as shown in FIG. 4, as the abnormal altitude determination processing in step 104 in FIG. 2, when the altitude obtained from the reception signal of the receiver 1 is out of the allowable range (−2000 m to +8000 m) (point in FIG. 4). In P6), it may be detected that there is an abnormality.

Further, as an abnormality detecting operation, as shown in FIG. 5, the transition of the positioning (latitude / longitude) every predetermined time (for example, every second) obtained from the reception signal of the receiver 1 is as follows.
When the vehicle speed exceeds a normal vehicle speed (for example, 0 to 200 km), that is, when the point is larger than the maximum moving distance determination value r (the point P _{i in} FIG. 5 changes to the point P _{i + 1} ), May be detected.

As another embodiment, as shown in FIG.
Microcomputer 6, direction sensor 7, and vehicle speed sensor 8
A GPS receiver 9, a control switch 10, a map memory 11, a CRT controller 12, and a display device 13. Then, the position of the vehicle is obtained from the outputs of the azimuth sensor 7 and the vehicle speed sensor 8, the dead reckoning navigation (or the map matching method) is used, and the GPS measurement result is abnormal using the satellite reception by the GPS receiver 9 as well. For example, the position may be displayed only by dead reckoning navigation.

Further, as another mode, a process as shown in FIG. 7 may be performed. That is, the microcomputer executes step 10
It initializes with 0 (count value of the counter N = 0) and demodulates satellite data. Then, in step 201, the pseudo distance is measured. Then, the microcomputer proceeds to step 20.
2 is used to calculate the positioning. Then, in step 203, the current position (latitude, longitude) P _i and the previous position (latitude, longitude) P _i
It is determined whether or not the absolute value of the difference from _i-1 is greater than a predetermined value r. If | P _i -P _i-1 | ≧ r, the count value N of the counter is set to “2” as abnormal. Step 201
And in steps 202 → 203, | P _i −P _i−1 | <
If r is normal, the process proceeds to step 205. At step 205, it is determined whether or not N = 0. At this time, since N = 2, "1" is subtracted from the count value N of the counter at step 206, and | P _i -P _i-1 at steps 201 → 202 → 203.
If | <r is normal, the process proceeds to steps 205 and 206. At step 205, it is determined whether or not N = 0.
Since it is 1, "1" is subtracted from the count value N of the counter in step 206 to make N = 0. Then, the process proceeds to steps 201 → 202 → 203, and | P _i −P _i−1
If | <r is normal, the process proceeds to step 205. At this time, since N = 0, display is performed in step 207.

As described above, in this embodiment, step 203
And the current position (latitude, longitude) _Pi and the previous position (latitude,
If the absolute value of the difference from the (longitude) P _i-1 is larger than the predetermined value r, no display is performed, but if the normal state of | P _i −P _i−1 | <r is not determined three consecutive times, it is determined in step 207. Is not displayed, erroneous detection can be further prevented.

In step 103 of FIG. 2, the data from the satellite is roughly classified into orbit data, time correction data, and transmission time data. However, only the transmission time data may be demodulated.

Further, in addition to the processing of FIG. 2 in the above-described embodiment, when it is determined that four satellites having a small PDOP value have an abnormality, the other satellites are used for the satellites. May be used for normal positioning and display. That is, it is determined whether or not the satellites other than the four satellites having the small PDOP value are normal.
At this time, the processing of FIG.
As soon as four satellites with small values become normal, more precise positioning and display by these satellites is performed.

Further, as a modified example of this other example, a defective satellite is specified by using a technique disclosed in Japanese Patent Application Laid-Open No. 3-108609, and signals from other satellites excluding the defective satellite are identified. May be used for normal positioning and display. Also in this case, the check processing of FIG. 2 for the defective satellite is continuously performed, and the positioning and display by this satellite may be performed as soon as the satellite becomes normal.

[0030]

As described in detail above, according to the present invention,
An excellent effect of always detecting abnormal positioning (erroneous positioning) of the GPS is exhibited.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a GPS navigation device for a vehicle.

FIG. 2 is a flowchart.

FIG. 3 is a diagram showing a transition of positioning and display contents.

FIG. 4 is a diagram showing a transition of positioning.

FIG. 5 is a diagram showing a transition of positioning.

FIG. 6 is an overall configuration diagram of another example of a vehicle GPS navigation device.

FIG. 7 is a flowchart.

FIG. 8 is a diagram corresponding to claims.

[Explanation of symbols]

Reference Signs List 1 receiver 2 receiver altitude detecting means, map altitude detecting means, microcomputer as judging means 4 CD-ROM as information storage means S1 to S4 GPS satellites

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroyasu Fukaya 1-1-1 Showa-cho, Kariya-shi, Aichi Japan Denso Co., Ltd. (56) References JP-A-3-191814 (JP, A) JP-A-61 -137086 (JP, A) JP-A-4-80679 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01C 21/00-21/36 G01S 5/14 G09B 29/00 -29/10

Claims (2)

(57) [Claims] 1. A vehicle, comprising: a plurality of GPS satellites;
And a receiver for receiving signals from a plurality of GPS satellites received by the receiver.
Receiver altitude detecting means for detecting the altitude of the receiver; information storage means for storing map information including altitude information;
From the latitude / longitude of the receiver
Map altitude for calculating the altitude of the receiver by the information storage means
Detecting means;Said By means of receiver altitude detectionWas detectedReceiver height
Every timePositioning accuracy area forWhen,SaidMap altitude detection means
By receiver altitudeOverlap with the high precision area
Whether or notJudgeRuMeans  ToHave The determination means includes the altitude positioning accuracy area and the altitude accuracy
If the area does not overlap, determine that there is an abnormality Specially
GPS navigation system for vehicles. 2. A pre-Symbol-size constant means, after determining abnormality and repeats the subsequent abnormality determination operations including the receiving operation from a satellite receiver, intended to perform a normal GPS navigation When no abnormality is The GPS navigation device for a vehicle according to claim 1.