JP2838186B2 - Navigation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation device, and more particularly to a device for acquiring and displaying navigation information with high accuracy.

[0002]

2. Description of the Related Art Position information obtained by receiving a radio wave from a position determination assisting system such as a GPS satellite or from a position determination device attached to a vehicle is converted to a CD-RO.
In recent years, the in-vehicle navigation device for displaying on a liquid crystal display screen together with map information stored in a storage medium such as M has been remarkably put into practical use.

[0003] When a conventional navigation device cannot sufficiently receive GPS data from a GPS satellite, for example, in a tunnel, directly below a high-rise building, or an underground road, an autonomous vehicle such as an angular velocity sensor or a distance sensor mounted on a vehicle is used. Based on the output from the navigation sensor, the position of the own vehicle is obtained independently of the GPS data.

FIG. 5 shows an example of a basic configuration block diagram of a conventional navigation device. The rotational angular velocity of the vehicle from the angular velocity sensor 111 such as a vibration gyroscope and the distance information from the distance sensor 112 are supplied to the CPU 100, and the current position and the traveling direction of the own vehicle are obtained based on the information. The GPS data received from the GPS satellites via the GPS antenna is transmitted to the GPS data receiving unit 115, subjected to predetermined processing, supplied to the CPU 100 as GPS data, and the current position and the traveling direction of the own vehicle are determined. Desired.

[0005] CD-ROM 113 stores navigation map information such as map information.
The map data read from the CD-ROM 113 via the CPU 14 is processed by the CPU 100, and the information on the current position and the traveling direction of the vehicle is sent to the display 116. Thus, the map information screen around the own vehicle position is displayed on the display 116, and the own vehicle position and the traveling direction are marked on the map screen.

In the above configuration, when the GPS data cannot be sufficiently received, the position detection accuracy of the own vehicle is determined by detecting the rotational angular velocity information from the angular velocity sensor (vibrating gyro) 111 and the vehicle velocity (distance) information from the distance sensor 112. Depends on accuracy. At this time, considering the vibrating gyroscope as the angular velocity sensor 111, it is necessary to appropriately process the vibration gyroscope in consideration of the drift of the gyroscope itself and the drift of the processing circuit for the voltage signal output from the piezoelectric ceramic for detecting the vibration gyroscope. There is a problem.

There is also a problem that the sensitivity of the vibrating gyroscope itself varies from vibration gyroscope to vibration gyroscope. Further, there is a problem that the number of pulses output from the distance sensor when the tire makes one rotation is different due to a structural difference depending on a vehicle type. In addition, the size of the tire differs for each vehicle, and there is a problem that the amount of movement of the vehicle per pulse varies depending on the road surface condition, the tire pressure, and the presence or absence of a slip. In this case, there is a problem that the detection accuracy of the current position of the vehicle is not constant and the detection accuracy is deteriorated.

Accordingly, the present applicant has previously proposed a navigation device capable of accurately estimating and obtaining the current position, the traveling direction, the traveling speed, and the like even in a situation where the positioning state by GPS is poor. (Japanese Patent Application 5-1)
No. 58054).

In this proposal, when the positioning state by the GPS is basically good and the traveling speed of the moving body is higher than a predetermined speed, for example, several km / h or more, the error of the positioning data by the GPS is negligible. Switches from data obtained from an autonomous navigation sensor including an angular velocity sensor and a distance sensor to data obtained by GPS. At the same time, the angular velocity and the traveling speed are corrected for each predetermined condition by the data received from the GPS satellites by an inferential calculation based on the outputs from the angular velocity sensor and the distance sensor, and the latest correction value is set to R
It is stored in a memory such as AM.

On the other hand, when the positioning condition by GPS becomes poor or when the traveling speed becomes lower than a predetermined set speed, the data used for positioning is obtained from the GPS data by the self-contained navigation sensor including the angular velocity sensor and the distance sensor. Switch to the data obtained from. However, the data from the angular velocity sensor and the distance sensor are corrected based on the latest correction values stored in the memory, and the current position, current direction, and current traveling speed are estimated.

[0011]

With the navigation device having the above-described structure, a map screen including a road to a destination and a mark of the position of the vehicle are displayed on the display screen. For example, FIG. As shown in ()), when the vehicle travels along the road R, if a high-precision measurement of the vehicle position is performed, a traveling locus T1 indicated by a dotted line along the width center of the road R is obtained. ,Is displayed.

[0012] However, GPS data usually includes
Since errors are included, errors also occur in positioning results obtained by normal navigation processing. Therefore,
When the positioning result based on the GPS data is superimposed and displayed on the map screen of the display as it is, as shown in FIG. 5B, the traveling locus T2 is displayed shifted from the road.

As a result, when position information such as longitude and latitude obtained based on GPS data, traveling direction, own vehicle speed and the like are used as reference information, the own vehicle position is sequentially estimated using the output of the angular velocity sensor and the distance sensor. Since the estimation process is performed based on the reference information including the error, the error is accumulated, and the obtained traveling trajectory deviates from the correct traveling trajectory along the road. For example, as shown in FIG. 6C, when a subsequent estimation process is performed based on reference information such as the position of the own vehicle including an error at the position P in FIG. 6B, a thick solid line in FIG. As shown in the figure, a traveling locus increasingly deviated from the road R is displayed.

It is an object of the present invention to provide a navigation device which can obtain and display accurate navigation information along a road on a map screen displayed on a display without being affected by errors included in GPS data. To provide.

[0015]

In order to achieve the above object, a navigation device according to the present invention comprises a GPS positioning unit for receiving a positioning signal from a GPS satellite to obtain GPS data as positioning information, and a self-contained navigation sensor. And a guess processing unit for guessing the vehicle position and the traveling direction based on a predetermined reference value by using the detection signal from the control unit, and outputting guess data as guess positioning information, the GPS positioning unit and the guessing processing unit. In a navigation device that displays the positioning information obtained in step 2 together with map information on a display, a map matching process for collating the GPS data with the map information and converting the GPS data into map data conforming to the map information And a guessing process in the guessing processing unit using the obtained map data as the reference value. Here, when the map data is not supplied to the map matching processing unit, the estimation processing is performed using the GPS data as the reference value. Further, the guess data from the guess processing unit is provided with an index for identifying each data and supplied to the map matching processing unit. The map data obtained by the map matching process and provided with a corresponding index is provided. Is used as the reference value to which the corresponding index is assigned, and the estimation processing of the estimation processing unit is executed.

[0016]

According to the present invention, the position of the own vehicle is determined by using a detection signal from the self-contained navigation sensor as a map data reference value obtained by performing a map matching process by comparing GPS data obtained from a GPS satellite with map information. The travel direction is estimated and displayed on the display together with the map information. Here, when no map data is supplied, the GPS data
An estimation process is performed using the data as the reference value. In addition, an index for identifying each data is assigned to the guess data, and an index corresponding to the map data is also assigned, and the processing for the data corresponding to each index is executed.

[0017]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of a navigation device according to the present invention. This embodiment includes a first processing unit 1 that executes a navigation process, and a second processing unit 2 that executes a process such as self-contained navigation positioning,
For example, an angular velocity sensor 5 and a distance sensor 6 are connected to the second processing unit 2, and angle information obtained by integrating the angular velocity signal and distance information obtained by integrating the distance sensor signal are supplied. . The GPS positioning unit 3
A predetermined process is performed on the GPS signal received via the GPS antenna ANT, and the GPS data is transmitted to the first processing unit 1.

The first processing unit 1 sends a GP
S data to the second processing unit 2 and the GP
A normal navigation process is executed based on the S data, and navigation information (own vehicle position and traveling direction) is displayed on the display unit 4 together with map data read from a built-in CD-ROM.

The estimation processing section 21 of the second processing section 2 receives the GPS data supplied from the first processing section 1 and executes the above estimation processing based on the detection signals from the angular velocity sensor 5 and the distance sensor 6. Estimated data (own vehicle position, traveling direction, vehicle speed) is obtained and sent to the first processing unit 1. At that time, the guess data is indexed in the order of GPS data reception timing and transmitted. This estimation process is executed based on a reference value determined from GPS data to be described later and map data after the map matching process.

The first processing unit 1 receives the estimated data,
The built-in map matching processing unit 11 corrects the error of the GPS data and the error of the estimated data and displays the own vehicle position at a correct position on the map information screen.

This correction will be described with reference to FIG. In the present embodiment, only the guess data is supplied from the second processing unit 2 to the first processing unit 1 having the navigation body function, thereby reducing the influence of errors.

FIG. 2A is a view similar to FIG. 6A, showing the road R and the own vehicle traveling locus T1 displayed on the display screen.
Is shown. As described with reference to FIG. 6B, the own vehicle position and the traveling locus T1 deviate from the road R due to an error in the GPS data, but the deviation is corrected by the map matching processing. For example, the position P in FIG. 2B is compared with the position P1 on the road R of the map, and the positioning position P
Since the position should be P1 on the road R, the positioning position P
Is forcibly changed and corrected to the position P1, and the subsequent estimation processing is executed.

Accordingly, as shown in FIG. 2 (C), the traveling locus obtained by performing the estimation process based on the corrected error-free position data is represented by a double circle in FIG. It is along R. As a result, not only can the display position shift due to GPS positioning accuracy be prevented, but also
Even if the PS data cannot be received, it is possible to accurately estimate the own vehicle position, azimuth (traveling direction), vehicle speed, and the like.

The reference value can be set by a setting method based on the GPS data and the map data after the map matching process. However, when the map data is not supplied from the map matching processing unit 11, the reference value is set to the raw GPS data. Reference data is set based on the map data, and when map data is supplied, the reference data is set based on the map data.

The index is added to the map data obtained by performing the map matching processing in the map matching processing section 11 and the estimation processing section 21 of the second processing section 2.
Is sent to the first processing unit 1 as the guess data. By repeating such estimation and map matching processing, navigation information without errors can be obtained.

By the way, the guess data from the second processing unit 2 is subjected to map matching processing in the first processing unit 1, and an error occurs due to the time required for processing when reflecting the obtained map data on the guess data. Occurs. The transmission and reception of the data with the above-mentioned index is effective for removing this error. That is, when the reference data is corrected with the map data, the index is referred to, for example, the processing is performed retroactively to eliminate a time error.
After calibrating the reference data in the second processing unit 2 by attaching the index to the map data and returning the map data after the map matching processing in the first processing unit 1, if the index is referred to, it is possible to estimate the predetermined time before. Data can be created.

That is, the GPS data is usually obtained at one-second intervals, and the mapper matching processing is executed based on the GPS data. Has a complicated arrangement relationship, it often takes more than one second for the arithmetic processing. In this case, the next GPS data arrives before the map matching processing for a certain GPS data ends. However, the time order after the map matching process displayed on the display is changed, which hinders the display. In such a case, if an index corresponding to each received GPS data is added to the map data or the estimation data as in the present embodiment, each GP
Since the map data for each S data reception timing (reception position of the own vehicle) is obtained, the above problem is solved.

Also, as shown in FIG.
On the so-called Y road that reaches the branch road,
When the vehicle enters the branch road, the GP
Since there is an error in the S data, it is difficult to determine which branch road has passed, and it is possible to know which branch road has traveled only after traveling a certain distance. In FIG. 4, the # number indicates the number (reception timing) given to the GPS data. In # 3 and # 4, it is determined which of the roads R1 and R2 the vehicle is traveling due to a GPS data error. Although it is not possible, since the roads R1 and R2 are far apart in # 5 and # 6, the traveling road can be determined. At this time, if an index is assigned to the map data or the estimation data for # 2, # 3, and # 4, the traveling locus of the own vehicle at each timing can be accurately obtained.

The operation procedure of this embodiment will be described with reference to the flowchart of FIG. The operation processing procedure in a state where the GPS data can be properly received is to determine whether or not the angular velocity sensor signal, the distance sensor signal, and the GPS data satisfy the reference value setting condition (step S1). If it is determined, the presence or absence of a reference value is determined (step S3). If there is no reference value, the process returns to the start, and if there is a reference value, the process proceeds to step S4 to perform an estimation process.
When it is determined that the reference value setting condition is satisfied,
After the reference value is set or updated (step S
2), the process proceeds to the estimation process of step S4.

The setting of the reference value may be based on map data or GPS data. When based on map data, the map data is referred to as a reference position (latitude X0,
The following guess calculation processing is performed as the longitude Y0) and the reference traveling direction φ. When the GPS data is used, (b) the satellite reception state is good, and (b) a dopping (Dilution of Pr) indicating the accuracy level depending on the satellite arrangement state.
(e) The value falls within a predetermined set value of a generally high-precision stage, and (c) The positioning accuracy is related to the fact that the accuracy is changed on the GPS satellite side, and the accuracy stage is a predetermined setting of a substantially high-precision stage. (D) the GPS speed data is equal to or more than a predetermined set value (for example, several km / h), and (e) the difference between the GPS speed data one second before and the latest GPS speed data is the predetermined set value ( (E.g., 2 km / h), (f) GPS azimuth data one second before and the latest G
Reference value setting conditions such as that the difference between the PS azimuth data is within a predetermined set value (for example, 2 degrees) and (g) that the detected angle change is within a predetermined set value (for example, 1 degree) are used. The latest position data that satisfies all of the reference setting conditions (a) to (f) at least several times in succession is used as reference position information such as latitude and longitude, and the latest azimuth data is used as reference traveling direction information.

Subsequently, a guess calculation process is executed based on the angular velocity sensor signal, the distance sensor signal, and the reference value (step S).
4) An index is added to the obtained guess data and transmitted to the first processing unit 1 (step S5). First processing unit 1
The (map matching processing unit 11) performs map matching processing on the received guess data and returns map data provided with the same index assigned to the guess data to the second processing unit 2 (step S6). ).
Next, the second processing unit 2 determines whether or not the map data has been received (step S7). If the map data has not been received, the process returns to step S1, and if the map data has been received, the angular velocity sensor signal, the distance The estimation calculation process is executed based on the sensor signal and the map data (step S8a), and the estimation calculation process is executed based on the angular velocity sensor signal, the distance sensor signal, and the GPS data (step S8b).

Thereafter, a large error is included in the map data, or a cancellation instruction is given by a user's manual instruction.
It is determined whether or not it has been transmitted from the processing unit (navigation main body) 1 and received (step S9). If not, the first processing unit assigns an index to the guess data based on the map data in step S8a. 1 (step S10), and the process returns to step S6. When it is determined in step S9 that the release instruction has been received, the G obtained in step S8b is obtained.
An index is added to the guess data based on the PS data and sent to the first processing unit 1 (step S11), and the process returns to step S1.

[0033]

As described above, according to the navigation apparatus of the present invention, accurate navigation information along a road on a map screen displayed on a display is obtained without being affected by errors included in GPS data. And display are possible.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram showing an embodiment of a navigation device according to the present invention.

FIG. 2 is a diagram illustrating correction of an error in GPS data and an error in estimated data according to an embodiment of the present invention.

FIG. 3 is a flowchart showing an operation processing procedure according to the embodiment of the present invention.

FIG. 4 is a diagram for explaining an embodiment of the present invention.

FIG. 5 is a basic configuration block diagram of a conventional navigation device.

FIG. 6 is a diagram showing a display example of a map screen including a road reaching a destination on a display screen of a conventional navigation device and a mark of a vehicle position.

[Explanation of symbols]

 Reference Signs List 1 first processing unit 2 second processing unit 3 GPS positioning unit 4 display unit 5 angular velocity sensor 6 distance sensor 11 map matching processing unit 21 estimation processing unit

Continuation of the front page (56) References JP-A-63-274000 (JP, A) JP-A-6-4024 (JP, A) JP-A-4-13921 (JP, A) JP-A-3-291583 (JP , A) International Publication 93/5587 (WO, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01C 21/00

Claims (3)

(57) [Claims] 1. A GPS positioning unit that receives a positioning signal from a GPS satellite and obtains GPS data as positioning information, and uses a detection signal from a self-contained navigation sensor to determine the position of the vehicle based on a predetermined reference value. An estimation processing unit for estimating a direction and outputting estimated data as estimated positioning information;
In a navigation device for displaying positioning information obtained by the positioning unit and the inference processing unit together with map information on a display, the navigation device compares the GPS data with the map information,
A navigation device, comprising: a map matching processing unit that converts PS data into map data that conforms to the map information; and a guessing process performed by the guessing processing unit using the obtained map data as the reference value. 2. The navigation apparatus according to claim 1, wherein when the map data is not supplied to the map matching processing section, the estimation processing is performed using the GPS data as the reference value. 3. The inference data from the inference processing section,
An index for identifying each data is provided and supplied to the map matching processing unit, and the map data obtained by performing the map matching process, and the map data to which the corresponding index is provided, is used as the reference value to which the corresponding index is provided. The navigation device according to claim 1, wherein the estimation processing of the estimation processing unit is performed.