JP2003161622A - Navigation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure the position of its own device accurately and inexpensively even in such a condition that GPS signals are cut off. <P>SOLUTION: A cellular phone is connected to a navigating ECU having a GPS receiver through a connecting means. When the power source of a vehicle is turned on, the receiving condition of the GPS signal received by the GPS receiver is ascertained (S3). In the case the signal can be received (S4; Y), the current position of the own vehicle is accurately measured based on the GPS signal. In the case the power source is turned off at the preceding operation in such the condition that the GPS signal cannot be received (S2; Y), and in the case a sunshine sensor makes such a judgement that the own vehicle enters a construction such as an underground parking lot, a tunnel or the like (S8; Y), or in the case the current position of the vehicle is determined on a building street, the underground parking lot, the tunnel or the like (S10; Y) by referring map data, the cellular phone sends a signal automatically to a positional information service center and obtains position data (S11), and the position of the own vehicle is measured based on the positional data (S12). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation system having a location function for positioning the present position of a vehicle based on GPS signals received from GPS satellites.

[0002]

For example, a car navigation device mounted on a vehicle generally measures the current position of the vehicle on the basis of receiving a GPS signal from a GPS satellite by a GPS receiver, It has a location function that displays the current position and travel route together with a map on a display device. In addition, so-called radio navigation using such GPS signals and so-called self-contained navigation for obtaining the relative position of the vehicle based on the detection of the azimuth sensor and the distance sensor mounted on the vehicle are also used together. There is.

However, if the vehicle cannot receive GPS signals from, for example, an underground parking lot or a tunnel, or cannot accurately receive GPS signals from a high-rise building, etc.
When entering the PS signal cutoff environment, it becomes impossible to measure the position of the own vehicle, and if this state continues for a long time, the position of the own vehicle on the display screen may deviate from the actual position.
In this case, the self-contained navigation is used in the GPS signal cutoff environment, but with this, the cumulative error is large, and it is not possible to perform positioning with sufficiently high accuracy.

By the way, in recent years, in mobile phones (including PHS terminals), when a call is made to a location information service center installed by a telecommunications carrier, information from a plurality of base stations (location registration information, etc.) There has been provided a location information service that uses the to check the current location of a specific mobile phone and informs the user. According to this position information service, it is possible to obtain stable position information with high accuracy in the reception area of the mobile phone.

Therefore, if a system in which the position information service in the above-mentioned mobile phone is combined with the car navigation device is configured, the location function can be realized without using a GPS signal. Therefore, a car equipped with a GPS receiver can be used. It is considered that the problem in the navigation device can be solved. However, in order to use the location information service, a usage fee (communication fee) is required, and therefore, there is a drawback that the communication fee charged to the user is large when the location information service is always used.

The present invention has been made in view of the above circumstances, and an object thereof is to be able to position the position of the own device with high accuracy even in a GPS signal cutoff environment, and at a low cost. Providing a navigation system.

[0007]

In order to achieve the above object, the present invention employs the means described in the claims. According to the invention of claim 1, normally, it is possible to position the present position of the own device with high accuracy based on the GPS signal received by the GPS receiver. When it is determined that the GPS signal cut-off environment cannot be received, the position data acquisition unit causes the mobile phone connected by the connection unit to automatically transmit to the position information service center to acquire the position data, and the position detection unit. Thus, the position of the own device can be detected based on the acquired position data.

Therefore, when the own device is in the GPS signal cutoff environment, the position information service can be used to detect the position of the own device with high accuracy, and the position of the own device on the display screen and the actual position can be detected. It is possible to solve the problem such as the slippage. And, since the GPS signal is used except when it is in the GPS signal blocking environment,
The use of the location information service by the mobile phone can be minimized, and the communication fee charged to the user can be reduced.

At this time, more specifically, the judging means can be configured as described in claims 2 to 4. That is, according to the second aspect of the present invention, it is considered that there is almost no significant movement of the aircraft between when the power is once turned off and when it is next turned on.
If the power is turned off while in the S signal cutoff environment, the GPS device will continue to operate when the power is turned on next time.
It is possible to judge with sufficient certainty that there is a signal blocking environment.

According to the third aspect of the present invention, by detecting the solar radiation sensor, the GPS signal does not reach (or is difficult to reach) when the vehicle is outdoors (in the daytime) and in underground parking lots, tunnels, etc. Since it can be distinguished from the time when the
It is possible to judge with sufficient certainty that there is a signal blocking environment.

According to the invention of claim 4, even at night when the solar radiation sensor cannot be used, the position (place) of the own device is estimated (recognized) based on the current position of the own device and the map data. Because it can be done,
When it is recognized that you have entered a place where GPS signals do not reach or become unstable, such as a building street, underground parking lot, or tunnel, you must judge with sufficient certainty that your aircraft is in a GPS signal blocking environment. You can

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is applied to a car navigation device mounted on a vehicle (automobile) will be described below with reference to the drawings. FIG. 2 schematically shows an electrical configuration of a main part of a navigation system (car navigation system) 1 according to the present embodiment. This system 1 is carried by a navigation ECU 2 which constitutes a main body of a navigation device. It is configured by connecting a telephone 3 (including a PHS terminal). At this time, although not shown, the mobile phone 3 is detachably connected via a connection means (serial interface or the like) provided in the navigation ECU 2.

The navigation ECU 2 is mainly connected to a control device section 4 which functions as a control means.
The S receiver 5, the power detection unit 6, the map data device 7, the memory unit 8 and the like are provided. Also, this navigation ECU
The signals from the solar radiation sensor 9 and the timepiece 10 provided in the vehicle are input to the 2 (control device unit 4), and the display of the display device 11, which is, for example, a full-color liquid crystal display, is controlled. It has become. still,
The display device 11 is arranged in an instrument panel portion of a vehicle,
The operation switch unit (not shown) is provided.

The GPS receiver 5 includes a GPS antenna 1
2 receives the GPS signal from the GPS satellite, and G
It is designed to demodulate the PS signal. The power source detection unit 6 is adapted to detect the on / off state of the vehicle power source (ACC). Further, the map data device 7 is
It is composed of a map data source such as a DVD for storing map data and its drive device. The memory unit 8
Is, for example, an EEPROM and stores the reception state of the GPS receiver 5. In this case, when the power supply (ACC) of the vehicle is turned off, the reception state of the GPS signal immediately before that is stored. It has become.

The control unit 4 includes a CPU, an R
Mainly composed of a microcomputer consisting of an OM, a RAM, an input / output interface and a bus line connecting them, and the software configuration (execution of programs) to know the current position of the vehicle, a location function, and a purpose designated by the user. Navigation processing such as a route guidance function for searching and guiding a route to the ground is executed.

The location function measures the current position of the vehicle based on the GPS signal received by the GPS receiver 5, displays the road map on the display device 11 based on the map data around the current position, and The current position (and traveling direction) of the own vehicle, which is superposed and positioned, is displayed. Further, the route guidance function automatically calculates (searches) a recommended travel route from the starting point (current position) of the vehicle to the destination specified (searched) by the user's operation, and obtains the requested travel. The route is displayed on the screen of the display device 11 to guide the destination.

In the mobile phone 3, for example, when a call is made to a location information service center installed by a telecommunications carrier, a specific mobile telephone using information (location registration information, etc.) from a plurality of base stations. It is possible to check the current position of No. 3 and receive the position information service to inform the user. At this time, this mobile phone 3
In the connected state between the navigation ECU 2 and the navigation ECU 2, the control unit 4
Is capable of instructing the mobile phone 3 to automatically make a call (automatic dial) to the location service center, and also to capture the position data acquired by the mobile phone 3 from the location information service center. You can do it.

Then, as will be described later in the explanation of the operation,
In the present embodiment, the control device section 4 judges whether or not the own vehicle (GPS receiver 5) is in the GPS signal blocking environment in which the GPS signal cannot be correctly received by the software configuration, and the GPS signal blocking environment is set. When it is judged that there is,
The mobile phone 3 is caused to automatically make a call to a position information service center to acquire position data, and the position of the vehicle is detected based on the position data. Therefore, the control device unit 4 includes a determination unit, a position data acquisition unit,
It functions as a position detecting means.

At this time, more specifically, the control unit 4
Determines that the GPS signal blocking environment is present in the following three cases. That is, firstly, on the basis of the memory of the memory unit 8, when the GPS receiver 5 is not able to receive a GPS signal, the power is turned off, and then the power is turned on. When the vehicle recognizes that it has entered a building such as an underground parking lot or a tunnel based on the detection signal, thirdly, based on the current position of the vehicle and map data,
When the vehicle recognizes that it has entered a place where the GPS signal does not reach or is unstable, such as a building street, underground parking lot, tunnel, etc., when it corresponds to at least one of them, the GPS signal blocking environment It is determined that

Next, the operation of the above configuration will be described with reference to FIG. The flowchart of FIG. 1 illustrates a processing procedure regarding detection (positioning) of the current position of the vehicle, which is executed by the control device unit 4 (navi ECU 2) when the vehicle is powered on. Here, it is assumed that the user connects his / her mobile phone 3 to the navigation ECU 2 through the connecting means when getting on the vehicle.

That is, when the power source detection unit 6 detects that the power source of the vehicle is turned on (step S1), the memory of the memory unit 8 is read out at the next step S2 and the GPS is turned off at the previous power-off time. It is determined whether the signal has been successfully received. Here, when GPS reception is not possible at the previous power-off time, that is, when the power is off in the state where the GPS receiver 5 cannot receive the GPS signal (Yes in step S2), It is determined that the vehicle is in the GPS signal blocking environment, and the process proceeds to step S11 described below.

On the other hand, if GPS reception was possible when the power was turned off last time (No in step S2), the reception status of the GPS signal by the GPS receiver 5 is confirmed and reception is possible in the next step S3. If it is (Step S
(Yes in 4), in step S5, the positioning process of the own vehicle based on the GPS signal is performed, and then the processes from step S3 are repeated. Thus, in normal times, that is, when the vehicle is not in the GPS signal blocking environment, accurate positioning of the current position of the vehicle is performed based on the GPS signal.

On the other hand, when the GPS signal cannot be received (No in step S4), step S6
At the step S6, it is determined whether or not the vehicle is traveling at night based on the signal from the clock 10, and if it is daytime (at step S6 N
o) In the next step S7, the detection signal of the solar radiation sensor 9 is confirmed, and based on the signal, whether the own vehicle is outdoors, whether it is indoors, that is, whether the vehicle has entered the building such as an underground parking lot or a tunnel. Is determined (step S8). Even when it is determined that the vehicle has entered the building such as an underground parking lot or a tunnel (Yes in step S8), it is determined that the vehicle is in the GPS signal blocking environment, and the process proceeds to step S11 described later.

If it is not determined that the vehicle has entered the building such as an underground parking lot or a tunnel based on the detection signal of the solar radiation sensor 9 (No in step S8), in the next step S9. By referring to the map data, it is determined whether the current position of the vehicle is a place where the GPS signal becomes unstable such as a building street or a place where the GPS signal does not reach such as an underground parking lot or a tunnel. In this case, in step S7, the underground parking lot, the tunnel, and the like are again determined in consideration of the case where the solar radiation sensor 9 cannot detect the light due to a light or the like. When it is determined that the host vehicle is located in the building street, underground parking lot, tunnel, or the like (Yes in step S10), the host vehicle is determined to be in the GPS signal blocking environment, and the process proceeds to step S11. .

As described above, steps S2, S8,
If it is determined in any of S10 that the own vehicle is in the GPS signal blocking environment, in step S11, the mobile phone 3 is caused to automatically make a call to the position information service center to acquire position data. It has become. Then, in the next step S12, the vehicle position is detected based on the position data. At this time, even if the GPS signal cannot be received, stable position information can be obtained with high accuracy in the reception area of the mobile phone 3, and the location function can be realized without using the GPS signal.

Even during execution of the position detecting process using the mobile phone 3, it is constantly monitored whether or not the GPS signal reception state is restored (step S13), and when the GPS signal reception becomes possible. (Yes in step S13
s), the connection of the mobile phone 3 to the location information service center is cut off (step S14), and G from step S3
It returns to the positioning using the PS signal. Further, as described above, when it is not determined that the own vehicle is in the GPS signal cutoff environment in any of the steps even though the GPS signal cannot be received (No in step S10),
Factors other than the environment, such as an abnormality (fault) of the GPS receiver 5, may be considered, so the abnormality process is performed in step S15.

As described above, according to this embodiment, in the normal state, the current position of the own vehicle can be positioned with high accuracy based on the GPS signal received by the GPS receiver 5, and the own vehicle can also receive the GPS signal. Cannot be received (difficult to receive), it automatically determines that the GPS signal blocking environment is present, and
In the PS signal cutoff environment, the position information service of the mobile phone 3 can be used to detect the position of the own vehicle with high accuracy, and the position of the own vehicle and the actual position on the screen of the display device 11 can be detected. It is possible to solve the conventional problems such as slippage.

Further, at this time, since the GPS signal is used except when the own vehicle is in the GPS signal cutoff environment, the use of the position information service by the mobile phone 3 is the minimum necessary and the user Communication charges to be incurred can be kept low. As a result, according to this embodiment, G
Even in the PS signal cutoff environment, it is possible to obtain the excellent effect that the position of the own vehicle can be positioned with high accuracy and the cost can be reduced.

The present invention is not limited to the above-mentioned embodiment, and for example, the navigation ECU 2 and the mobile phone 3 may be connected by using a radio wave or the like.
Instead of the clock 10, the time information of the GPS signal may be used to determine whether it is daytime or nighttime. Furthermore, the present invention is not limited to the vehicle navigation device, but can be applied to a portable navigation device or the like. The present invention can be appropriately modified and implemented without departing from the spirit of the invention.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, and is a flowchart showing a processing procedure regarding positioning of a current position of a vehicle.

FIG. 2 is a block diagram showing an electrical configuration of a main part of the navigation system.

[Explanation of symbols]

In the drawing, 1 is a navigation system, 2 is a navigation EC
U, 3 are mobile phones, 4 are control devices (determination means, position data acquisition means, position detection means), 5 is a GPS receiver,
6 is a power source detection unit, 7 is a map data device, 8 is a memory unit,
9 is a solar radiation sensor, 10 is a clock, and 11 is a display device.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04Q 7/20 H04Q 7/04 Z 7/34 H04B 7/26 106A (72) Inventor Koji Kato Kariya, Aichi Prefecture 1-chome, Showa-cho, DENSO Co., Ltd. (72) Inventor Yoshiyuki Hamanaka 1-1-chome, Showa-cho, Kariya City, Aichi F-term in DENSO, a stock company (reference) 2C032 HB02 HB22 HB25 HC08 HD03 HD16 2F029 AA02 AB07 AB13 AC02 AC09 AC13 5H180 AA01 BB05 BB13 CC12 FF05 FF13 FF22 FF33 5J062 AA03 AA08 AA11 BB01 CC07 DD14 FF01 HH07 5K067 AA01 BB36 EE02 EE10 FF16 FF32 JJ52 JJ53 JJ56 JJ64

Claims (4)

[Claims] 1. A navigation system having a GPS receiver for receiving GPS signals from GPS satellites and having a location function for positioning the present position of the own device based on the GPS signals, to which a mobile phone can be connected. Connection means, a judging means for judging whether or not the GPS signal is in an environment where the GPS signal cannot be received by the own device, and when the judging means determines that the GPS signal is in an environment for shutting down the mobile phone, Position data acquisition means for automatically making a call to a position information service center for checking the current position of the mobile phone by using a base station and acquiring position data from the position information service center, and acquired by the position data acquisition means. And a position detecting means for detecting the position of the own device based on position data. Deployment system. 2. The determination means is such that the GPS receiver is G
The navigation system according to claim 1, wherein when the power is turned off in a state where the PS signal cannot be received and then the power is turned on, it is determined that the GPS signal cutoff environment is present. 3. The GPS signal interception environment is set when the determination means recognizes that the vehicle has entered a building such as an underground parking lot or a tunnel based on a detection signal from the solar radiation sensor. The navigation system according to claim 1, wherein the navigation system makes a determination. 4. The judging means has entered a place where GPS signals do not reach or become unstable, such as a building street, an underground parking lot, or a tunnel, based on the current position of the own device and map data. 4. When the fact is recognized, it is determined that the GPS signal cutoff environment is present.
Navigation system according to any one of.