JP2003344065A - On-vehicle navigation apparatus, navigation method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle navigation apparatus and a method for modifying the bearing of one's own motor vehicle capable of correcting the bearing of one's own motor vehicle in a short period of time and to provide a program for implementing the method. <P>SOLUTION: The on-vehicle navigation apparatus corrects the bearing of one's own motor vehicle according to the vector bearing difference θ, between a first vector AB connecting a reference point A to a first point B computed by navigation and a second vector AC connecting the reference point A to a second point C specified by predetermined location data. Since the vector bearing difference reflects error in the bearing of one's own motor vehicle on the first point, it is possible to speedily correct the bearing of one's own motor vehicle according to the vector bearing difference. For example, in the case that the vector bearing difference exceeds a predetermined threshold value, the bearing of one's own motor vehicle is corrected. The predetermined location data is, for example, location data included in an optical beacon or a radio beacon, location data acquired from GPS signals having specific reliability, or location data acquired by ETC (electronic toll collection) systems. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted navigation device that displays a map image around a vehicle position, and more particularly to a technique for correcting the vehicle direction.

[0002]

2. Description of the Related Art Generally, a vehicle-mounted navigation device detects the current position of its own vehicle, reads map data in the vicinity of the current position from a data storage medium such as a CD-ROM or a DVD, and displays it on a screen. Further, a vehicle position mark indicating the own vehicle position is displayed in the center of the screen, and map data in the vicinity is scrolled around the vehicle position mark according to the progress of the own vehicle, so that map information around the own vehicle position can always be seen. It is like this.

Generally, a Global Positioning System (GPS) is used to identify the position of the vehicle. GPS provides continuous three-dimensional position and time data when the visibility of at least four satellites is secured. The direction of the GPS is calculated by using the data (GPS data) obtained from such GPS to determine the own vehicle direction. To calculate the GPS azimuth, the GPS data is sampled multiple times to improve the accuracy.

In a situation where GPS data cannot be obtained, the autonomous navigation system estimates the vehicle position from a known position and calculates the vehicle direction. Autonomous navigation systems typically use gyro signals, vehicle speed pulses and reverse signals.

[0005]

However, the above-described conventional calculation of the vehicle direction tends to cause a large deviation in the vehicle direction when the vehicle leaves the multi-story parking lot or the underground parking lot. Power off vehicles parked in these parking lots
Even if it is turned on, the GPS data cannot be received well. Therefore, the vehicle direction is calculated from the known position, that is, the position where the vehicle is parked, by using the autonomous navigation system. In this case, since the number of turns of the vehicle is large in the multi-storey parking lot or the underground parking lot, it is not possible to accurately calculate the own vehicle direction. Also, in the parking lot with turntable, turn the power on.
Since the turntable on which the vehicle is placed rotates in the FF state, the own-vehicle direction when the power is off and the one after the rotation when the power is on are different, and there is a large error in calculating the own-vehicle direction based on the known position. Will occur. In such a case, for a long time until the vehicle leaves the parking lot and can receive a predetermined number of GPS data, the own vehicle display mark displayed on the screen is significantly different from the actual own vehicle position and direction. There was a problem that it would end up.

Therefore, the present invention solves the above-mentioned problems of the prior art, and is capable of correcting the vehicle azimuth in a short time, a vehicle-mounted navigation device and a vehicle azimuth correction method, and a program for implementing this method. The purpose is to provide.

[0007]

The present invention provides a first vector connecting a reference point and a first point calculated by navigation, and a second vector specified by the reference point and predetermined position data.
Is a vehicle-mounted navigation device that corrects the vehicle azimuth according to the vector azimuth difference from the second vector connecting to the point. Since the vector heading difference reflects the error of the vehicle heading associated with the first point, the vehicle heading can be promptly corrected according to the vector heading difference.

In the vehicle-mounted navigation device,
For example, if the vector heading difference is equal to or greater than a predetermined threshold value, the vehicle heading is corrected. Further, the predetermined position data is, for example, position data included in an optical beacon or a radio wave beacon, position data obtained from a GPS signal having predetermined reliability, or ETC (Electronic Toll Collec).
location system).

Further, in the vehicle-mounted navigation device, for example, the reference point is included in the data stored in the backup memory when the power source of the vehicle-mounted navigation device is turned off, and the correction of the vehicle direction is performed by the vehicle-mounted navigation device. Perform after turning on the power of the device. Further, the correction of the vehicle azimuth includes moving the reference point to the second point.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

(Structure) FIG. 1 is a block diagram showing the overall structure of a vehicle-mounted navigation device according to an embodiment of the present invention. The illustrated vehicle-mounted navigation device includes a disk driver 1, an operation unit 2, a communication device 3, a vehicle speed sensor 4, a GPS receiver 5, a gyro sensor 6, and a VICS (Vehicle Information and Communicatio).
n System) sensor 7, reverse sensor 8, navigation controller 10, display 30, and speaker 3
Including 1. The disk driver 1 reads data and programs from a recording medium such as a CD-ROM or a DVD that stores various kinds of map data necessary for map display and route search and programs as necessary. The operation unit 2 is for a user to input various instructions to the navigation controller 10. The communication device 3 is an in-vehicle telephone or the like for communicating with a service center (a service center of a manufacturer or other organization). The vehicle speed sensor 4 outputs a vehicle speed according to a pulse generated at every constant traveling distance. G
The PS receiver 5 receives a GPS signal sent from a GPS satellite and detects the current vehicle position and vehicle direction.
More specifically, the GPS receiver 5 receives radio waves transmitted from a plurality of GPS satellites, performs three-dimensional positioning processing or two-dimensional positioning processing, calculates the absolute position and azimuth of the vehicle, and Is output together with the positioning time. The gyro sensor 6 is a sensor for detecting the direction of the vehicle. The vehicle direction is calculated by sampling a predetermined number of directions obtained from the current vehicle position and the current vehicle position one sampling time ΔT before. The VICS sensor 7 receives traffic information provided by an optical beacon (infrared ray), a radio wave beacon (quasi-microwave), or the like. When the vehicle passes under a transmitter that transmits the optical beacon or the radio beacon, traffic information is transmitted from the transmitter to the vehicle. Some of this traffic information is
Includes transmitter position data. As will be described later, one of the features of the present embodiment is that the vehicle direction is corrected using the position data of the transmitter included in the optical beacon or the radio beacon. The reverse sensor 8 outputs a signal indicating the reverse movement of the vehicle. Vehicle speed sensor 4, gyro sensor 6
And the reverse sensor 8 enables autonomous navigation,
It complements GPS-based navigation.

The display 30 displays a map image of the area around the vehicle together with a vehicle position mark, a departure point mark, a destination mark, etc., based on the image data output from the navigation controller 10, and a guide route on this map. Or to display. The speaker 31 outputs a message to the user based on the audio data output from the navigation controller 10.

The navigation controller 10 includes a buffer memory 11 and interfaces (I / F) 12-1.
8, control unit 19, map drawing unit 20, operation screen / mark generation unit 21, guide route storage unit 22, guide route drawing unit 23,
Mark storage unit 24, mark drawing unit 25, image synthesizing unit 2
6, a backup memory 27, a voice output unit 28, and a connection ID storage unit 29. The buffer memory 11 temporarily stores the map data and programs read by the disk driver 1 from the recording medium. The interfaces 12 to 18 are respectively connected to the operation unit 2, the communication device 3, the vehicle speed sensor 4, the GPS receiver 5, the gyro sensor 6, the VICS sensor 7 and the reverse sensor 8 and form an interface with the control unit 19. The control unit 19 is composed of, for example, a microcomputer and controls the entire navigation controller 10. For example, the control unit 19 controls the GPS signal from the GPS receiver 5, the vehicle speed sensor 4 for the autonomous navigation, the gyro sensor 6, the reverse sensor 8 and the VICS sensor 7.
Various navigation-related items such as processing the output signal of the vehicle to calculate the vehicle position and vehicle direction, and searching the guide route from the departure point to the destination under the search conditions set using the read map data. The process of is executed. The azimuth calculation / correction processing performed by the control unit 19 will be described later with reference to the flowchart.

The map drawing section 20 uses the map data read in the buffer memory 11 to draw a map image. The operation screen / mark generation unit 21 displays various menu screens (operation screens) and own vehicle position marks according to the operation status.
Generates various marks such as a cursor. The guide route storage unit 22 stores the data of the guide route searched by the control unit 19. Specifically, the guide route storage unit 22 is changed during the search regarding data regarding all nodes (coordinates of points displayed in latitude and longitude) from the starting point to the destination of the guide route searched by the control unit 19. The data of the guide route thus selected is stored. The guide route drawing unit 23 reads the guide route data (node string) from the guide route storage unit 22 and draws the guide route in a color and line width different from those of other roads. The mark storage unit 24 relates to a predetermined-shaped icon (brand icon, category icon, etc.) given as information indicating the position of the target property on the map screen, and a simple-shaped mark given in place of this icon. Pre-store data. The mark drawing unit 25 includes the control unit 1
Based on the control of 9, the drawing processing of the data read from the mark storage unit 24 is performed. The image synthesizing unit 26 synthesizes the images output from the map drawing unit 20, the operation screen / mark generating unit 21, the guide route drawing unit 23, and the mark drawing unit 25, and outputs the images to the display 30.

The audio output unit 28 outputs an audio signal to the speaker 31 based on the signal from the control unit 19. Connection I
The D storage unit 29 stores addresses of service centers of manufacturers and other institutions, connection IDs, passwords, and the like. The backup memory 27 is composed of a non-volatile memory such as an EEPROM or a flash memory, and backs up various data to be backed up. For example, as will be described later, the backup memory 27 stores data of the vehicle position (final vehicle position) and the vehicle direction when the power supply of the vehicle-mounted navigation device is turned off.

(Principle of Operation) Next, the operation of this embodiment will be described. As will be described below, the present embodiment is an in-vehicle navigation system such as an environment where GPS signals cannot be received or reception conditions are poor such as a multi-storey parking lot or an underground parking lot, or a parking lot with a turntable. One of the features is that the apparatus is provided with a process for correcting in a short time the error in the vehicle direction that occurs when the vehicle turns while the power of the device is temporarily turned off.

As shown in FIG. 2, A in the underground parking lot 40
When a vehicle parked at a point goes out from the point A through the exit 41 to the ground, the vehicle goes through the route indicated by the solid line,
An erroneous (large error) path indicated by a broken line is displayed on the display 30. In most cases, the GPS signal cannot be received in the underground parking lot 40. Therefore, the vehicle position and the vehicle direction are calculated by autonomous navigation.
The autonomous navigation is performed by a known method based on the output signals of the vehicle speed sensor 4, the gyro sensor 6 and the reverse sensor 8. If many turns are made in the underground parking lot 40 or traveling on an inclined surface, an error occurs in the vehicle position and the vehicle direction calculated by the autonomous navigation. This error also occurs due to the detection error of the gyro sensor 6.

In this embodiment, in order to correct the error of the vehicle direction displayed on the screen at an early stage, the position data having an acceptable predetermined reliability is used. Such position data includes position data included in optical beacons and radio beacons. For example, when a VICS transmitter is installed at point C in FIG. 2, position data can be acquired from the beacon received by the VICS sensor 7 shown in FIG.
At this time, it is assumed that the vehicle position displayed on the screen is point B and the vehicle direction is the direction indicated by the arrow. Here, as shown in FIG. 3, attention is focused on the angle formed by the vector AB from the point A to the point B, which is the parking position, and the vector AC from the point A to the point C. This angle is defined as a vector orientation difference θ as shown in FIG. When the vector heading difference θ is equal to or larger than a predetermined threshold value, the heading is corrected and the vehicle position on the screen is changed from the point B to the point C. Then, the reference point is updated from A to C. The own vehicle direction on the screen immediately after this direction change is different from the actual direction, but the own vehicle position on the screen moved to the actual own vehicle position or its vicinity, so It becomes possible to match the actual vehicle position.

The position data having a predetermined reliability that can be obtained at the point C is not limited to the beacon, but the GP can be used.
It may be position data obtained from the S signal or position data obtained by ETC. A normal vehicle azimuth calculation using a GPS signal is performed by acquiring a predetermined number of positioning data. Therefore, even if the predetermined number of positioning data cannot be acquired at the point C in FIG. 3, the position data of the point C can be acquired by using the coordinate data obtained from the GPS signal. However, in order to improve the accuracy of the azimuth correction, it is preferable to judge whether or not the coordinate data obtained from the GPS signal has a predetermined reliability as described later. When the ETC is used, the ETC receiver is attached to the navigation controller 10 in the configuration shown in FIG.

As described above, in the azimuth correction using the position coordinates of two points, the position accuracy of the reference point (point A) is required, but it is stored in the backup memory 27 when the power of the navigation device is turned off. The position data is treated as having a predetermined reliability.

(Operation) FIG. 4 is a flow chart showing the calculation / correction processing of the own vehicle direction using the GPS signal, and FIG. 5 is a flow chart showing the calculation / correction processing of the own vehicle direction using the above operation principle. Both of the flowcharts are executed by the control unit 19 shown in FIG.

First, in step S11, the control unit 19 sets G
The GPS signal from the PS receiver 5 is received. Next, in step S12, the control unit 19 determines whether or not the predetermined positioning condition is good. Two-dimensional positioning, three-dimensional positioning, accuracy deterioration index (DOP: Dilution Of Precis
ion), vehicle speed, etc. For example, if there are 10 vehicles
When the three-dimensional positioning is continued for a predetermined time while traveling at a speed of km / s or more, the control unit 19 determines that the positioning condition is good. Next, in step S13, the control unit 19 stores the positioning data in the internal memory. Next, in step S14, the control unit 19 determines whether or not a predetermined number of positioning data are stored. If the determination result is NO, the control unit 19 ends the process. If the determination result in step S14 is YES, the control unit 19 determines in step S1.
In step 5, the GPS bearing is calculated from the stored positioning data.
Next, in step S16, the control unit 19 determines the vehicle direction and GPS.
It is determined whether the azimuth difference from the azimuth is greater than or equal to a predetermined threshold value. The own vehicle direction is the direction obtained by autonomous navigation. If the decision result in the step S16 is NO, the control section 19 ends the process. If the decision result in the step S16 is YES, the control section 19 corrects the azimuth according to a predetermined method.

Next, the processing of FIG. 5 will be described. The process of FIG. 5 is performed by the control unit 19 after the navigation device is powered on. Step S21 shown in FIG.
Then, the control unit 19 detects that the power of the navigation device is turned on. Next, in step S22, the control unit 1
9 acquires the own vehicle position from the backup memory 27 and sets it as the reference point A shown in FIG. And step S23
Then, the control unit 19 starts a loop including steps S24 to S30. In step S24, the control unit 19 calculates the vehicle position. This own vehicle position corresponds to point B in FIG. The vehicle position when the vehicle is moving in the underground parking lot 40 in FIG. 2 or immediately after the exit 41 is calculated by autonomous navigation. Next, in step S25, the control unit 19 determines whether the position data has been acquired by a method other than autonomous navigation. This position data corresponds to point C in FIG. The position data acquired here is the position data included in the output signal of the VICS sensor 7, the position data included in the ETC signal, and the position data obtained from the GPS signal. Any one of these position data is controlled by the control unit 1.
When 9 is detected, the determination result of step S25 is YES, and the process proceeds to step S26. If the decision result in the step S25 is NO, the control section 19 ends the process.

In step S26, the control unit 19 determines whether the acquired position data has a predetermined reliability. The position data acquired using the VICS sensor 7 or the ETC receiver is treated as having a predetermined reliability. Further, the position data which is the data obtained from the GPS signal and which satisfies the above-mentioned determination condition of step S12 of FIG. 4 is treated as having a predetermined reliability. Next, in step S27, the control unit 19 calculates the vector AB and the vector AC shown in FIG. Then, in step S28, it is determined whether the vector heading difference θ is equal to or larger than a predetermined threshold value.
If the decision result in the step S28 is YES, the control section 19 corrects the vehicle azimuth (position) in a step S29.
In the example of FIG. 2, the control unit 19 moves the bearing from the point B to the point C. Then, in step S30, the control unit 19 sets the point C as a new reference point A. If the decision result in the step S28 is NO, the control section 19 bypasses the process of the step S29, executes the step S30, and ends the process.

As described above, since the vehicle direction is corrected by using the position data having a predetermined reliability, it is possible to correct the vehicle position on the screen to the actual vehicle position or its vicinity at an early stage. Will be possible.

The main point of the navigation method realized by the flowchart shown in FIG. 5 is that a first vector AB connecting the reference point A and the first point B calculated by the navigation is calculated (step S27). , A step of calculating a second vector AC connecting the reference point A and a second point C specified by predetermined position data (step S2)
7) and the step of correcting the own vehicle azimuth according to the vector azimuth difference θ formed by the first and second vectors (step S2).
9) is included.

When the control unit 19 is regarded as a device, the control unit 19 executes the flow chart shown in FIG.
The navigation controller 10 including means for calculating a first vector AB connecting the reference point A and the first B point calculated by the navigation (control unit 19 and step S
27), means for calculating a second vector AC connecting the reference point A and a second point C specified by predetermined position data (control unit 19 and step S27), and the first and second The gist is to include means (control unit 19 and step S29) for correcting the own vehicle azimuth according to the vector azimuth difference θ formed by the vector.

FIG. 6 shows a computer-readable recording medium such as a DVD or a CD-ROM mounted on the disc driver 1. As shown in FIG. 6, a map database area 51 is formed outside the disk-shaped recording medium 50, and a program area 52 is formed inside the map database area 51. By storing the program shown in FIG. 4 in the program area 52, the program shown in FIG. 4 can be loaded into the navigation controller 10. As a result, the in-vehicle navigation device that does not have the function realized by the program of FIG. 4 can be provided with this function. That is, the program stored in the program area 52 causes the computer, that is, the control unit 19 to calculate the first vector AB connecting the reference point A and the first B point calculated by the navigation (step S27).
And a procedure for calculating a second vector AC connecting the reference point and a second point C specified by predetermined position data (step S27), and a vector orientation difference formed by the first and second vectors. The gist is to execute the procedure (step S28) of correcting the vehicle direction according to θ. Also,
It is also possible to download the program shown in FIG. 4 to the navigation controller 10 using the communication device 3 instead of the disk driver 1.

The embodiment of the present invention has been described above.
The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention.

[0030]

As described above, according to the present invention,
It is possible to provide a vehicle-mounted navigation device that can correct the vehicle direction in a short time, a method for correcting the vehicle direction, and a program for implementing this method.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a problem of a conventional technique and an example of azimuth correction which can be executed in the present embodiment.

FIG. 3 is a diagram for explaining the principle of azimuth correction according to the present invention.

4 is an operation flowchart of the vehicle-mounted navigation device shown in FIG.

5 is another operation flowchart of the vehicle-mounted navigation device shown in FIG.

6 is a diagram showing an example of a disk-shaped recording medium usable in the vehicle-mounted navigation device shown in FIG.

[Explanation of symbols]

1 Disk Driver 2 Operation Unit 3 Communication Device 4 Vehicle Speed Sensor 5 GPS Receiver 6 Gyro Sensor 7 VICS Sensor 8 Reverse Sensor 10 Navigation Controller 11 Buffer Memory 12-18 Interface (I / F) 19 Control Unit 20 Map Drawing Unit 21 Operation Screen Mark generation unit 22 Guide route storage unit 23 Guide route drawing unit 24 Mark storage unit 25 Mark drawing unit 27 Buffer memory 28 Voice output unit 29 Connection ID storage unit 30 Display 31 Speaker 40 Underground parking 41 Exit 50 Recording medium 51 Map database area 52 program area

Claims (10)

[Claims] 1. A first calculated by a reference point and navigation
To correct the vehicle azimuth according to the vector azimuth difference between the first vector connecting the point and the second vector connecting the reference point and the second point specified by the predetermined position data. Characteristic vehicle-mounted navigation device. 2. The in-vehicle navigation device according to claim 1, wherein the vehicle azimuth is corrected when the vector azimuth difference is equal to or larger than a predetermined threshold value. 3. The vehicle-mounted navigation device according to claim 1, wherein the predetermined position data is included in an optical beacon or a radio wave beacon. 4. The vehicle-mounted navigation device according to claim 1, wherein the predetermined position data is position data obtained from a GPS signal having predetermined reliability. 5. The predetermined position data is ETC (Elec
(3) The vehicle-mounted navigation device according to claim 1 or 2, which is position data obtained by the tronic Toll Collection System. 6. The reference point is included in data stored in a backup memory when the power supply of the vehicle-mounted navigation device is turned off, and the correction of the vehicle orientation is performed after the power supply of the vehicle-mounted navigation device is turned on. The vehicle-mounted navigation device according to any one of claims 1 to 5, wherein: 7. The vehicle-mounted navigation device according to claim 1, wherein the correction of the vehicle azimuth moves the reference point to a second point. 8. The first calculated by the reference point and the navigation
Means for calculating a first vector connecting the point and the second vector connecting the reference point and a second point specified by predetermined position data, and the first and second And a means for correcting the own vehicle azimuth in accordance with the vector azimuth difference formed by the vector. 9. The first calculated by the reference point and the navigation
Calculating a first vector connecting the point and the second vector connecting the reference point and a second point specified by predetermined position data; And a step of correcting the own vehicle azimuth according to the vector azimuth difference formed by the vector. 10. A computer is provided with a procedure for calculating a first vector connecting a reference point and a first point calculated by navigation, and a second point specified by the reference point and predetermined position data. A navigation program for executing a procedure of calculating a second vector to be connected and a procedure of correcting a vehicle azimuth according to a vector azimuth difference formed by the first and second vectors.