JPH0712909A - Navigation apparatus with positional correction function - Google Patents

Abstract

PURPOSE:To achieve a prevention of expansion of error in the position of a vehicle by estimating detection errors in the position immediately below as detected by a beacon to perform a positional correction for a range in which the detection errors are added to the positional information of the beacon as long as the position of the vehicle differs significantly as caused by navigation. CONSTITUTION:A CPU 23E of an arithmetic/display device 23 starts a positional correction interrupt program. a difference Y is computed between the position A of a vehicle determined with a GPS receiver 21 and a setting position B of a transmission antenna 24. On the other hand, an error limit X is set according to the direction in which the vehicle runs. Then, when the difference Y between the position A of the vehicle with GPS receiver 21 and the setting position B with a VICS beacon receiver 22 exceeds the error limit X, the position A of the vehicle determined with the GPS receiver 21 is replaced with the setting position B of the transmission antenna 24. But no correction is executed when the error Y is below the error limit X.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is based on position information identified from beacon radio waves when passing through the reception area of beacon radio waves for each vehicle position obtained by computing the information collected every moment. TECHNICAL FIELD The present invention relates to a navigation device with a position correction function that corrects a position.

[0002]

2. Description of the Related Art A large number of low-power relay stations are arranged along a road to continuously transmit local traffic information and road information in the form of beacon radio waves using a common radio frequency. VICS (Vehicle Information and Comunication SV)
ystem: Road-to-vehicle information system) Beacon systems are being put to practical use. The VICS beacon system aims at effective use of roads by realizing smooth road traffic, rationalization of road management, and timely provision of information to drivers.

In the VICS beacon system, a beacon radio wave is transmitted from a pair of transmitting antennas provided above the road to form a local receiving area. On the other hand, on the vehicle side,
Beacon receiver is installed. Beacon receiver has (a) a data reception function that extracts various information from the FM modulation component of beacon radio waves, and (b) directly below the antenna that detects the position directly below the antenna using the AM modulation component of beacon radio waves. It also has a detection function.

Various types of information communicated by the VICS beacon system include position information (coordinate position where a transmitting antenna is installed) that specifies a receiving area, vehicle traveling direction, road lane information, intersection name, toll road ahead. It is roughly classified into a fixed one such as a toll list, and a fluid one such as traffic congestion, display of construction sections and detours, weather information, and road conditions.

The direct detection function of the beacon receiver is
It is possible to display various data-communication information at appropriate timing on the CRT screen mounted on the vehicle that is running, and the navigation device mounted on the vehicle calculates the momentary vehicle position. It can also be used for correction.

According to the direct detection function of the beacon receiver,
The position directly below the transmitting antenna in the receiving area can be detected with high accuracy within ± several meters. Therefore, for example, the momentary vehicle position calculated by the navigation device is replaced with the coordinate position of the data-transmitted transmitting antenna at the timing of the position detection directly below, and subsequent vehicle position calculations are performed based on this new initial value. To continue. As a result, the accuracy of the vehicle position that is displayed momentarily on the map image can be dramatically improved.

The vehicle position correction using the output of the beacon receiver uses a navigation device such as a gyroscope or a gas inertial sensor in which errors are accumulated as the vehicle travels unless artificial correction is performed. It is effective in navigation devices. The accumulated position error is replaced with position information of the transmitting antenna each time the beacon radio wave passes directly below the transmitting antenna, and is offset at once.

[0008] On the CRT screen of the navigation device, the vehicle position that is displayed overlaid on the map image gradually protrudes from the road as the vehicle travels. Will be repositioned.

FIG. 7 is an explanatory diagram of the VICS beacon system. In FIG. 7, (a) is the reception state of beacon radio waves,
(b) shows beacon radio waves in the in-phase region, and (c) shows beacon radio waves in the anti-phase region.

In FIG. 7A, the relay station 71 is connected to the road 7
A pair of transmitting antennas 72A, 7 installed at a position above 0
A transmitting antenna 72 having 2B and oriented toward the in-phase region side
7 (b) through the in-phase beacon wave in FIG. 7 (b) through the transmission antenna 72B directed to the anti-phase region side.
The beacon radio waves in the opposite phase region of are transmitted respectively.

A gigahertz band radio wave channel is assigned to the beacon radio wave, and the beacon radio wave is an FM modulation component obtained by FM-modulating a data signal of various information and an analog amplitude signal for detecting the position directly below the transmitting antennas 72A and 72B. And an AM-modulated component obtained by AM-modulating.

The beacon radio wave in the in-phase region of FIG. 7 (b) and FIG.
The beacon radio waves in the reverse phase region of (c) share the data signal (FM modulation component), but the phase of the analog amplitude signal (AM modulation component) is opposite. That is, in the beacon radio wave in the in-phase region, the synchronization signal of the data signal and the analog amplitude signal have an in-phase relationship, but in the beacon radio wave in the anti-phase region, the synchronization signal of the data signal and the analog amplitude signal have an anti-phase relationship.

Therefore, at positions directly below the transmitting antennas 72A and 72B, the analog amplitude signals in the in-phase region and the anti-phase region interfere with each other and cancel each other, forming a minimum point of the reception intensity of the analog amplitude signal.

The vehicle 73 traveling on the road 70 receives a beacon radio wave from the beacon receiver in the vehicle through the receiving antenna 74. Then, when the reception intensity of the beacon radio wave rises to a level at 100 to 500 m from the position directly below 75, demodulation of the FM modulation component is started, the data signal is separated, and various data are accumulated. The driver can use various information such as character information and still image information through the CRT screen in the vehicle.

When the reception intensity of the beacon radio wave reaches a set level (corresponding to 30 to 50 m from the position directly below), the beacon receiver starts detecting the position directly below using the analog amplitude signal. For the detection of the position directly below, (1) Detect the minimum point of the reception strength of the analog amplitude signal, (2) Detect the in-phase / anti-phase (or anti-phase / in-phase) conversion point of the analog amplitude signal and the synchronization signal, etc. It is executed by the method of.

The beacon receiver compares the phase relationship between the analog amplitude signal and the synchronization signal to identify the in-phase region and the anti-phase region. For example, the traveling direction of the vehicle 73 with respect to the relay station 71 is obtained from the phase relationship between the analog amplitude signal and the synchronization signal before detecting the positions directly below the transmitting antennas 72A and 72B.

According to the identified traveling direction, only the data related to the front of the traveling direction of the vehicle 73 is selected from the accumulated various data and displayed on the CRT screen mounted on the vehicle at the timing when the position directly below is detected. It Information such as intersections that have passed is useful for vehicles passing through the opposite lane, but is basically worthless for vehicle 73.

The beacon receiver further corrects the position of the vehicle 73 calculated by the navigation device mounted on the vehicle. Vehicle 73 calculated by the navigation device
The position of is replaced with the position coordinate of the relay station 71 stored as various data at the timing when the position directly below is detected. After that, the navigation device calculates the position of the vehicle 73 every moment with the position coordinates of the relay station 71 as an initial value.

[0019]

In FIG. 7 (a), the reception intensity of the beacon radio wave and the reception intensity of the analog amplitude signal are shown by gentle curves, but the reception state of the beacon radio wave received by the vehicle 73 is shown. Fluctuates drastically during running as indicated by the dotted line in the figure. Along with this, the reception strength of the analog amplitude signal also fluctuates drastically as shown by the dotted line in the figure.

The beacon radio waves in the gigahertz band have a high degree of straightness, and interfere with each other in a complicated manner due to the influence of blocking and reflection by surrounding buildings, street trees, other vehicles (traffic conditions) on the road, etc. In addition to the position directly under 72B,
It may form a local minimum of the analog amplitude signal.

Accordingly, (1) in the method of detecting the minimum point of the reception intensity of the analog amplitude signal and identifying the position directly below, the minimum point of the spurious just before the position directly below the transmitting antennas 72A and 72B is detected, and the position immediately below is detected. There is a possibility of misjudging the position.

Further, in a region where the beacon radio wave transmitted by the transmission antenna 72A and the beacon radio wave transmitted by the transmission antenna 72B overlap, mutual analog amplitude signals cancel each other out to reduce the reception strength of the analog amplitude signal, The accuracy of phase comparison of amplitude signals is reduced. And
The fluctuation of the reception intensity of the beacon radio wave due to the influence of the surrounding environment further deteriorates the accuracy of phase comparison of the analog amplitude signals through the fluctuation of the reception intensity of the analog amplitude signals.

Therefore, (2) the method of detecting the in-phase / anti-phase (or anti-phase / in-phase) conversion points of the analog amplitude signal and the synchronization signal to identify the position directly below is used when the reception intensity of the beacon radio wave is low. , The error in the position directly below the identified position increases.

On the other hand, the reception intensity of the beacon radio wave is shown in FIG.
Not only the traveling direction of the road 70 in (a) but also the width direction of the road 70 greatly changes. Transmitting antenna 72
A and 72B are normally provided on the lane at one end of the road 70. In this case, in the lane on the other side, compared to the lane on the one side, the reception intensity of beacon radio waves is significantly reduced, and if the road is a wide road that exceeds three lanes on each side, the position detection immediately below is started. In some cases, the set level cannot be reached and various data sent from the relay station 71 cannot be used normally.

On a wide road where the transmitting antennas 72A and 72B are provided on the lane at one end of the road 70,
Each time the lane is moved toward the lane on the other end, the detection error of the position directly below increases.

On the other hand, in recent years, a navigation device utilizing absolute position measurement using a communication satellite and a navigation device using a plurality of sensors such as an acceleration sensor in a gyro have been put into practical use, and the accuracy of the calculated vehicle position is improved. Therefore, the accumulation of vehicle position errors due to traveling is not as remarkable as before.

Therefore, when the beacon radio wave is significantly reduced, such as when the vehicle passes through a lane far from the transmitting antennas 72A and 72B or when the surrounding traffic conditions block the beacon radio wave, the error in detecting the position directly below is large. too much,
There is a possibility that the "position correction by replacement" may be performed on a vehicle position having a larger error than the vehicle position calculated by the navigation device.

It is an object of the present invention to provide a navigation device with a position correction function in which the position correction by replacement does not increase the error in the vehicle position.

[0029]

FIG. 1 is an explanatory diagram of the basic configuration of the present invention. In FIG. 1, a navigation device with a position correction function according to claim 1 calculates a momentary position of a moving vehicle 11 on the basis of information collected by the vehicle 11 side by time, and a local means. Beacon receiver 13 that identifies position information of the reception area from the beacon radio wave when passing through the reception area of the beacon radio wave arranged in And a correction unit 14 that corrects the momentary vehicle position calculated by the calculation unit 12 based on the position information identified by the beacon receiver 13 when the passage timing is detected. In the navigation device with a correction function, the closest approaching distance to the transmitting unit 10 when passing through the receiving area is identified, and the passing timing is incorrect. When the difference between the reference means 15 for estimating the distance, the momentary vehicle position by the computing means 12, and the position information by the beacon receiver 13 is smaller than the error distance, the correction by the correcting means 14 is performed. Control means 16 for stopping
And, are provided.

A navigation device with a position correcting function according to a second aspect is the navigation device with a position correcting function according to the first aspect, wherein the reference means 15 identifies the traveling direction from a beacon radio wave, and the forward / reverse direction of the traveling direction. It is a reference means for varying the error distance based on the distinction of.

According to a third aspect of the present invention, there is provided a navigation device with a position correcting function, a calculating means for calculating a momentary position of a running vehicle based on information continuously collected on the vehicle side, and locally. When passing through the reception area of the placed beacon radio wave, identify the position information of the reception area from the beacon radio wave, and a beacon receiver for detecting the passage timing of the closest position to the transmitter of the beacon radio wave, In a navigation device with a position correction function, comprising: a correction unit that corrects the momentary vehicle position calculated by the calculation unit based on the position information identified by the beacon receiver when passage timing is detected. A reference means for identifying a reception state of a beacon radio wave when passing through the reception area and estimating an error distance of the passage timing; And a control means for stopping the correction by the correction means when the difference between the vehicle position by the step and the position information by the beacon receiver is smaller than the error distance. .

[0032]

In the navigation device with the position correcting function of the present invention, the vehicle position calculated by the navigation device is not blindly replaced with the position information obtained through the beacon radio wave, but the position directly below the position detected in the reception area of the beacon radio wave. Only if the vehicle position calculated by the navigation device is significantly different, beyond the range in which this detection error is added to the position information of the reception area (position directly below the transmitting antenna) obtained from the beacon radio wave, by estimating the detection error of Execute "position correction by replacement".

In the navigation device with position correcting function according to the first aspect, the reference means 15 and the control means 16 are added. The reference unit 15 estimates the detection error of the position directly below the sending unit 10 (accurately, on the transverse line of the road passing through the position directly below the sending unit 10) according to the distance from the sending unit 10. , Set.

If the distance from the transmission unit 10 is large, the reception intensity of the beacon radio wave is lowered, the possibility of erroneous detection of the passage timing of the closest position of the transmission unit 10 in the vehicle 11 is increased, and the detection error of the passage timing is also increased. Increase. The control means 16 determines whether or not the correction should be executed, and if it is inappropriate, stops the correction.

The distance from the sending unit 10 is (1) the distinction between the forward direction and the reverse direction of the traveling direction, (2) the sensor that detects the white line to identify the current traveling lane, and (3) the reception intensity of the radio wave. It is identified by a detection device or the like that estimates the driving lane.

The calculating means 12 calculates the position of the vehicle 11 every moment based on the information collected every moment through the gyro, the gas inertial sensor, the GPS receiver and the like. When the beacon receiver 13 passes through the reception area of beacon radio waves,
Data of at least position information of the reception area is accumulated from the beacon radio wave, and the timing at which the vehicle 11 passes the closest position of the transmission unit 10 is detected.

The correction means 14 executes "position correction by replacement" in which the position of the vehicle 11 calculated by the calculation means 12 is replaced with the position information of the reception area acquired by the beacon receiver 13. The correction unit 14 is, for example, the transmission unit 10.
At the passage timing of the closest position to
The position of the vehicle 11 calculated by is replaced with the position information of the reception area by the beacon receiver 13.

In the navigation device with the position correction function according to the second aspect, the error distance is changed based on the distinction between the forward and backward directions of the traveling direction. For example, the transmitter of the VICS beacon system is installed such that the vehicle 73 traveling in the in-phase region (forward direction) of FIG.
72B is set to view. Therefore, the distance is short in the forward direction and is long in the reverse direction.

In the navigation device with position correcting function according to the third aspect, the reception state of the beacon radio wave when passing through the reception area is identified, and the error distance of the passage timing is estimated. The reception status of beacon radio waves is affected not only by the distance from the transmission section but also by the surrounding environment of the vehicle and traffic conditions, etc.If the reception status of beacon radio waves deteriorates, the passing timing of the closest position of the transmission section will be incorrect. The possibility of detection increases, and the detection error of the passage timing also increases.

The reception state of the beacon radio wave is (1) the reception intensity of the beacon radio wave, (2) the error rate of the data due to the FM modulation component, and (3) the analog amplitude signal of a certain amplitude or less after starting the position detection directly below. It is identified by detecting the received traveling distance and the like. In the case of (3), since it is determined whether or not the correction is executed after the vehicle passes the position directly below, it is necessary to additionally correct the distance traveled after the vehicle passes the position directly below.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is an explanatory view of the structure of the navigation system of the first embodiment, FIG. 3 is an explanatory view of the relationship between the traveling lane and the detection error, and FIG. In FIG. 3, (a) shows the driving lane and (b) shows the detection error.

Here, the error X is set according to the distinction between the forward direction / reverse direction (main direction / subordinate direction) of the traveling direction, and the vehicle position is provided by the navigation device and the VICS beacon receiver is provided at the direct position detection timing. Only when the difference between the position of the transmitting antenna and the position of the transmitting antenna exceeds the error X, "position correction by replacement" is executed. In other words, the vehicle position is corrected to the transmission antenna position only when the vehicle position is displayed at a position beyond the range of the front and rear X around the transmission antenna position.

In FIG. 2, the GPS receiver 21 receives the radio wave transmitted from the geostationary satellite 25 to detect the current position of the vehicle. The receiver 21A separates a necessary electric signal from the received radio wave and converts it into data for obtaining the current position of the vehicle. The data is immediately sent to the arithmetic / display unit 23 through the data sending unit 21B.

The VICS beacon receiver 22 receives beacon radio waves transmitted from the transmission antenna 24 arranged above the lane on one side of the road, and accumulates various information data including the installation position of the transmission antenna 24. To do. Further, the position immediately below the transmitting antenna 24 is detected by detecting the analog amplitude signal, and various information data is used at the detection timing of the position directly below.

The beacon radio wave received from the antenna provided on the rooftop of the vehicle is amplified through the high frequency circuit 22, band-selected, and converted into an intermediate frequency signal. The intermediate frequency signal is further band-selected by the intermediate frequency circuit 22B and converted into a baseband signal.

The FM data demodulation circuit 22C extracts FM modulation components including digital signals of various data from the baseband signal and restores the original digital data from the FM modulation components. The restored various data are transmitted through the communication unit 22E and the arithmetic / display unit 23 to the communication unit 23 of the arithmetic / display unit 23.
Sent to B.

The AM amplitude signal demodulation circuit 22D separates the analog amplitude signal from the baseband signal. The direct position detection circuit 22F detects the conversion point of the phase state (in-phase / reverse-phase relationship) of the analog amplitude signal and the synchronization signal as shown in FIGS. 7 (b) and 7 (c), and directly below the sending antenna 24. Identify the location. The traveling direction identification circuit 22G detects the phase relationship between the analog amplitude signal and the synchronization signal before the timing for detecting the position directly below, and identifies the forward / reverse direction of the traveling direction.

In the normal state, the arithmetic / display unit 23 displays G
The vehicle position data obtained by the PS receiver 21 is used as the I / O unit 23.
Input to CPU23E through A. At CPU23E,
This vehicle position is calculated on the map image data. The formed image data for display is displayed as an image on the display unit 26.

On the other hand, when the vehicle enters the transmission area of the transmission antenna 24, first, various data through the FM modulation component is input to the CPU 23E through the communication section 23B, and C
The PU 23E selects necessary data according to the distinction of the traveling direction and stores it in the memory 23F. Sending antenna 24
The data indicating the installation position of is stored in the memory 23F in a state of being translated into the data format for navigation used in the arithmetic / display unit 23. The installation position of the transmission antenna 24 is recalled to the CPU 23E at the timing of detecting the position directly below.

The traveling direction identified by the traveling direction identification circuit 22G is input to the CPU 23E through the I / O unit 23D. The immediately below position detection timing detected by the immediately below position detection circuit 22F is input to the CPU 23E through the I / O unit 23C.

The CPU 23E activates the position correction interrupt program at the position immediately below the position detection timing, compares the vehicle position calculated based on the data from the GPS receiver with the installation position of the transmission antenna 24, and obtains the difference, Only when this difference is larger than the set value of the error determined according to the traveling direction, the calculated vehicle position is replaced with the installation position of the transmission antenna 24.

In FIG. 3 (a), the traveling direction passing through the VICS beacon transmitting antenna 24 when viewed from the left is the main direction, and the traveling direction passing when viewed from the right is the slave direction. Also, VIC
Before and after passing the closest position of the S beacon transmitting antenna 24, the relationship between the analog amplitude signal and the synchronization signal changes from the same phase to the opposite phase in the main direction, and changes from the opposite phase to the same phase in the subsidiary direction.

Even on a road with a width of 2 lanes on each side of 16 m, as the distance from the lanes 1, 2, 3, 4 and the VICS beacon transmission antenna 24 increases, the range where the position directly below can be detected expands, and a number of passages are repeated. The expected value (average value) of the obtained detection error remarkably increases.

In FIG. 3B, the expected value of the detection error is
It increases linearly as the distance from the VICS beacon transmitting antenna 24 increases, and it is up to 8 up to the lane 2 in the main direction.
Although it is only m, it can reach a maximum of 16 m in the secondary lane 4.

In FIG. 4, when the CPU 23E of the arithmetic / display unit 23 of FIG. 2 starts the position correction interrupt program, in step 41, the difference between the vehicle position A obtained by the GPS receiver 21 and the installation position B of the transmission antenna 24 is calculated. Y is calculated. On the other hand, in step 42, the error limit X is set according to the traveling direction of the vehicle. That is, 6 m is set when the traveling direction is the main direction, and 12 m is set when the traveling direction is the sub direction.

If the difference Y between the vehicle position A by the GPS receiver 21 and the installation position B by the VICS beacon receiver 22 exceeds the error limit X, step 43
Then, the vehicle position A obtained by the GPS receiver 21 is replaced with the installation position B of the transmitting antenna 24, but the difference Y is the error limit X.
In the following cases, the correction is not executed.

The corrected vehicle position is displayed on the map image on the display unit 26 of the arithmetic / display unit 23. After that, the calculation of the image data in the CPU 23E is corrected at the installation position B of the sending antenna 24. Starting from the initial values,
It is executed every moment based on the data of the GPS receiver 21.

FIG. 5 is an explanatory diagram of the configuration of the navigation system of the second embodiment, and FIG. 6 is an explanatory diagram of the setting of the error limit. In FIG. 6, (a) shows an error limit and (b) shows an error limit setting program. Here, the error limit X is set according to the distinction of the reception intensity level of the beacon radio wave at the position detection timing immediately below, and the vehicle position and VI by the GPS receiver are set.
Only when the difference from the position of the transmitting antenna by the CS beacon receiver exceeds the error limit X, “position correction by replacement” is executed.

In FIG. 5, the receiver 51A of the GPS receiver 51 separates the data of the current vehicle position from the radio waves transmitted from the geostationary satellite 55. The data is sent to the arithmetic / display unit 53 through the data sending unit 51B.

The VICS beacon receiver 52 receives the beacon radio wave transmitted from the transmitting antenna 54 and separates the data of the installation position of the transmitting antenna 54. Further, the position directly below the transmitting antenna 54 is identified by detecting the analog amplitude signal. In the VICS beacon receiver 52, the beacon radio wave is converted into an intermediate frequency signal through the high frequency circuit 52. The intermediate frequency signal is further band-selected by the intermediate frequency circuit 52B and converted into a baseband signal.

The FM data demodulation circuit 52C extracts the FM modulation component from the baseband signal and restores the data at the installation position of the transmission antenna 54. AM amplitude signal demodulation circuit 5
2D extracts an analog amplitude signal from the baseband signal. The direct position detecting circuit 52F detects the in-phase / opposite phase conversion point of the analog amplitude signal and the synchronizing signal, and identifies the position directly below the transmitting antenna 54. Running direction identification circuit 52G
Identifies the traveling direction by examining the phase relationship between the analog amplitude signal and the synchronization signal.

The radio wave intensity detection circuit 52H rectifies, smoothes, and amplifies the received signal of the beacon radio wave, and creates an analog electric signal corresponding to the received intensity of the beacon radio wave. Calculation/
The CPU 53E of the display device 53 samples the analog electric signal through the I / O unit 53H at the timing of detecting the position directly below and estimates the reception intensity of the beacon radio wave.

In the normal state, the calculation / display unit 53 displays G
Vehicle position data from the PS receiver 51 is transferred to the I / O unit 53A.
Through the CPU 53E, and the CPU 53E forms display image data in which the mark of the vehicle position is superimposed on the map image based on the vehicle position data. The display image data is displayed as an image on the display unit 56.

On the other hand, when the vehicle enters the reception area of the beacon radio wave, first, the data of the installation position of the transmission antenna 54 is separated through the FM modulation component and is input to the CPU 53E through the communication section 53B. The CPU 53E stores the data of the installation position of the transmission antenna 54 in the memory 23F and recalls it to the CPU 53E at the timing of the position directly below.

The traveling direction of the vehicle is input to the CPU 53E through the I / O unit 53D, and the direct position detection timing is input to the CPU 53E through the I / O unit 53C. CPU5
3E activates the position correction interrupt program at the position detection timing immediately below, and sends the vehicle position by the GPS receiver 51 and the transmission antenna 54 by the VICS beacon receiver 52.
If the difference is larger than the error limit set according to the reception strength of the beacon radio wave,
The vehicle position by the GPS receiver 51 is replaced with the installation position of the transmission antenna 54 by the VICS beacon receiver 52.

In FIG. 6 (a), as shown in FIG. 3 (a), on a four-lane road in which the transmitting antenna 54 is installed on the side of the lane 1, the vehicle travels from the reception intensity of the beacon radio wave at the timing for detecting the position directly below. Can identify lanes. That is, as the distance from the lanes 1, 2, 3, 4 and the transmitting antenna 54 increases, the reception intensity of the beacon radio wave decreases, and the range (error limit) in which the position directly below can be detected expands.

In FIG. 6B, the flowchart of the arithmetic / display unit in the second embodiment is constructed by replacing step 42 of the flowchart of FIG. 4 with step 62 of FIG. 6B.

In step 42 of FIG. 4, the running direction of the vehicle is identified, and the error limit X is set according to the distinction between the main direction and the sub-direction, whereas in step 62 of FIG. The reception intensity of the beacon radio wave at the detection timing is detected, and the error limit X is set according to the level of the reception intensity of the beacon radio wave.

Then, as in the case of the first embodiment, the GP
Only when the difference Y between the vehicle position A by the S receiver 51 and the installation position B of the transmission antenna 64 by the VICS beacon receiver 52 is calculated and the difference Y exceeds the error limit X, the vehicle position A is transmitted by the antenna 54. It replaces with installation position B of.

[0070]

According to the navigation device with the position correction function of the present invention, the calculated vehicle position is not blindly replaced with the installation position of the transmitting antenna, so that an unsuitable correction due to the detection error of the position detection timing immediately below is performed. It doesn't have to happen. That is, there is no concern that the error in the vehicle position will increase due to the correction. Therefore, even in the lane on the side opposite to the transmitting antenna on a wide road, it is possible to secure certain accuracy and reliability in position correction.

Conventionally, even if the reception intensity of the beacon radio wave is too weak to start the direct under position detection, the level of the reception intensity of the beacon radio wave for starting the direct under position detection is lowered to actively collect data. Then, this data can be effectively used by the usage method with low accuracy in detecting the position directly below. That is, it is possible to use data that has been discarded without being used because it is impossible to detect the position directly below, while keeping in mind the limit.

According to the navigation device with the position correction function of the second aspect, the position correction can be performed by adding a slight program change to the arithmetic device while maintaining the existing circuit configuration without adding a special circuit or sensor. A function that secures a certain degree of accuracy and reliability can be realized.

According to the navigation device with a position correcting function of claim 3, when not only the lane on the side opposite to the transmitting antenna on a wide road but also the surrounding buildings and street trees disturb the beacon radio waves, the center separation is performed. When the band is provided with a tall wall, it is possible to secure a certain degree of accuracy and reliability in position correction even when the surrounding traffic conditions prevent normal reception of beacon radio waves.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a basic configuration of the present invention.

FIG. 2 is an explanatory diagram of a configuration of a navigation system according to the first embodiment.

FIG. 3 is an explanatory diagram of a traveling direction and a detection error.

FIG. 4 is a flowchart of a calculation / display unit.

FIG. 5 is an explanatory diagram of a configuration of a navigation system according to a second embodiment.

FIG. 6 is an explanatory diagram of setting an error limit.

FIG. 7 is an explanatory diagram of a VICS beacon system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 transmitting part 11 vehicle 12 computing means 13 beacon receiver 14 correcting means 15 reference means 16 control means

Claims (3)

[Claims] 1. A calculation means (12) for calculating the momentary position of the vehicle (11) during traveling, based on the information momentarily collected on the side of the vehicle (11), and a beacon arranged locally. A beacon receiver (1 that identifies position information of the reception area from the beacon electric wave when passing through the electric wave reception area and detects the passage timing of the closest position to the beacon electric wave transmission unit (10).
3) and, when the passage timing is detected, a correction unit that corrects the momentary vehicle position calculated by the calculation unit (12) based on the position information identified by the beacon receiver (13). In a navigation device with a position correction function including (14), a reference unit (15) for estimating an error distance of the passage timing by identifying a closest distance to the transmission unit (10) when passing through the reception area. ) And the difference between the momentary vehicle position by the computing means (12) and the position information by the beacon receiver (13) is smaller than the error distance, the correction means (14) Control means for canceling correction (16)
And a navigation device with a position correction function. 2. A navigation device with a position correction function according to claim 1, wherein the reference means (15) identifies a traveling direction from a beacon radio wave, and the direction of the traveling direction /
A navigation device with a position correction function, which is a reference unit that changes the error distance based on the distinction in the opposite direction. 3. A calculating means for calculating the momentary position of the vehicle on the basis of information continuously collected on the vehicle side, and a beacon radio wave reception region locally arranged. At the time of identifying the position information of the reception area from the beacon radio wave, and a beacon receiver for detecting the passage timing of the closest position to the transmitter of the beacon radio wave, if the passage timing is detected, In the navigation device with a position correction function, which has a correction unit that corrects the momentary vehicle position calculated by the calculation unit based on the position information identified by the beacon receiver, a beacon when passing through the reception area. Reference means for estimating the error distance of the passage timing by identifying the reception state of the radio wave, the momentary vehicle position by the computing means, and the beacon The difference between the position information by Shin machine, wherein when less than the error distance, the correction means according to the corrected position correcting function navigation apparatus characterized by the control means to stop, was provided.