JPH06180234A - Navigation apparatus for vehicle mounting - Google Patents

Abstract

PURPOSE:To provide an excellent navigation apparatus, for vehicle mounting, wherein it is not required for the user of a vehicle to set the initial position and the initial direction of the vehicle and it is not required to reset them even after the vehicle has been run. CONSTITUTION:A position is corrected by a GPS at every arbitrary time or at every arbitrary distance, and the correction amount of an own running direction is computed by the difference between the direction of a straight line connecting an mth corrected position by the CPS to an nth corrected position by the GPS and the direction of a straight line connecting the mth corrected position by the GPS to the own running position corrected by the GPS by using the mth corrected position as a starting point. When the corrected positions by the mth and nth GPSs are a prescribed value or higher and the corrected position by the nth GPS and the own running position at the nth correction are a prescribed value or higher, the nth position is corrected and, at the same time, the running direction of a vehicle is corrected.

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 for displaying the position and direction of a vehicle and map information around the vehicle.

[0002]

2. Description of the Related Art Conventionally, a vehicle-mounted navigation device of this type generally has a structure as shown in FIG. The configuration and operation will be described below. In FIG. 4, the GPS receiver obtained through the communication interface 105 by inputting the data of the angular velocity sensor 101 such as a geomagnetic sensor and the distance sensor 102 to the CPU 104 from the input interface 103 to obtain the vehicle position, the vehicle direction and the traveling locus. By comparing the absolute position information of 106 with the map data of the CD-ROM 107, the estimated vehicle position can be calculated, and the vehicle position on the map can be displayed on the display 109 via the image processing processor 108.

[0003]

However, in the above-mentioned conventional vehicle-mounted navigation device, it is necessary to set the initial position and the initial direction of the vehicle at the time of initial startup. For example, the current vehicle position on the map and the vehicle. If the direction was unknown, it was impossible to set the initial position and direction. Also, if you do not have the opportunity to correct the position or direction over a long distance, such as traveling on a new road not on the map, errors will accumulate in the calculated vehicle position and vehicle direction,
There was a problem of losing the correct vehicle position and direction.

Conventionally, in order to solve these problems, G
There is a method of correcting the vehicle position by adding a device for calculating the current position based on external information such as PS, but GPS has only position information and cannot correct the vehicle direction (GP.
S direction information also exists, but the reliability is low at a certain speed or less). Further, there is a problem that GPS position information may be disturbed due to multipath, a combination of satellites, etc., and it is necessary to select only effective GPS azimuth data.

The present invention solves such a conventional problem, and the user of the vehicle does not need to set the initial position and the initial direction of the vehicle. It is an object of the present invention to provide an excellent vehicle-mounted navigation device that can be reset without losing sight.

[0006]

In order to achieve the above object, the present invention uses GPS and a velocity sensor / azimuth sensor to perform position correction by GPS every arbitrary time or every arbitrary distance. The azimuth of a straight line connecting the GPS corrected position and the n-th GPS corrected position, and the m-th GPS corrected position and the position at the n-th GPS correction of self-sustained travel starting from the m-th corrected position. The correction amount of the self-supporting traveling azimuth is calculated from the difference between the azimuths of the connecting straight lines, and the correction position by the m-th and n-th GPS is equal to or more than the specified value, If it is equal to or more than the specified value, the traveling direction of the vehicle is corrected at the same time as the n-th position correction.

Further, the azimuth correction amount at that time is calculated by weighting the GPS azimuth and the self-standing azimuth, and is gradually converged by repeating the processing.

[0008]

Therefore, according to the present invention, the initial position setting and heading setting by GPS are unnecessary, and even if there is no opportunity to correct the position or heading over a long distance while traveling, only the vehicle position can be set by GPS. In addition, the vehicle direction can be corrected.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described in detail with reference to.

FIG. 1 shows a block diagram of the present embodiment, FIG. 2 shows an example of a flow chart, and FIG. 3 shows an example of an explanatory view of an azimuth calculating means.

In FIG. 1, 1 is a GPS receiver, 2 is G
The PS position calculating means analyzes the data sent from the GPS receiver 1 to calculate the GPS receiving position. 3 is a GPS position holding means for holding the GPS position at the time of the previous correction, and 4 is a GPS position absolute direction calculation means for calculating the absolute direction between the GPS position at this time and the GPS position at the time of the previous correction. is there. Reference numeral 5 is a speed sensor, and the speed detecting means 6 detects the vehicle speed from the data of the speed sensor 5. Reference numeral 7 is a moving distance calculating means for calculating the moving distance of the vehicle from the data of the speed sensor 5. Reference numeral 8 denotes an angular velocity sensor. Based on the data of the angular velocity sensor 8, the self-standing azimuth change detecting means 9 calculates the absolute azimuth between the GPS reception positions. 10 is an independent position calculation means,
The current self-sustained position is calculated from the outputs of the moving distance calculation means 7 and the self-sustained azimuth change detection means 9. Reference numeral 11 is a self-standing position holding means that holds the self-standing position last time, and reference numeral 12 is a self-standing position absolute azimuth calculating means that calculates the absolute azimuth between the previous and current self-standing positions. Numeral 13 is an azimuth difference calculating means, which is an absolute azimuth calculating means 4 between GPS positions and an absolute azimuth calculating means 12 between self-standing positions.
Calculate the azimuth correction amount from. Reference numeral 14 is an independent running azimuth calculating means for calculating an independent running azimuth, and 15 is a running azimuth correcting means, and the independent running azimuth calculating means 14 corrects the independent running azimuth.

Next, the operation of the above embodiment will be described. In FIG. 1, the GPS position calculation means 2 causes the GP
The data sent from the S receiver 1 is analyzed to calculate the GPS reception position, and G is calculated from the GPS position calculated this time and the GPS position at the time of the previous correction obtained from the GPS position holding means 3.
The absolute azimuth between PS positions calculates the absolute azimuth between the GPS reception positions.

On the other hand, the vehicle speed is detected by the speed detecting means 6 from the data of the speed sensor 5, and the moving distance calculating means 7 is used.
The moving distance by the speed sensor 5 is calculated by. Also,
Based on the data of the angular velocity sensor 8, the self-standing azimuth change detecting means 9 detects the amount of azimuth change. The self-sustained position calculation means 10 calculates the self-sustained position this time from the obtained movement distance and azimuth change amount, and the self-sustained position holding means 11 calculates the absolute azimuth calculation means 12 between the self-sustained position last time and the self-sustained position this time. Calculate the absolute azimuth between the previous and current independence positions.

Further, the absolute azimuth calculation means 4 between GPS positions
The absolute azimuth between the GPS reception positions obtained by
The absolute azimuth calculation means 12 between the self-standing positions calculates the azimuth correction amount by the azimuth difference calculation means 13 from the absolute azimuths between the previous and present self-standing positions, and the independent running azimuth calculation means 14 calculates the independent running azimuth.

Here, if the moving distance obtained by the moving distance detecting means 7 is equal to or greater than a certain value, it is determined that the corrected azimuth by GPS is effective, and the traveling azimuth correcting means 15 corrects the self-supporting traveling azimuth.

FIG. 2 is a flowchart showing a control flow for correcting the self-supporting traveling direction. The position is corrected by GPS at every arbitrary time or every arbitrary distance, and step 2
In step 1, it is determined whether the m-th position correction has occurred, and in step 22, it is determined whether the n-th position correction has occurred. Next, in step 24, it is determined whether the m-th and n-th GPS corrected positions are apart by a distance equal to or more than a specified value, and if they are not separated by a specified distance or more, the GPS position correction is further continued. , If the distance is more than the specified distance, proceed to step 26, n
It is determined whether or not the position corrected by the GPS for the first time and the autonomous traveling position at the time of the n-th correction are separated by a specified value or more. If the azimuth is corrected and the distance is not more than the specified distance, the traveling azimuth of the vehicle is not corrected and step 22
Return to.

Next, referring to the vector diagram shown in FIG. 3, a method for obtaining the corrected self-supporting traveling azimuth will be described.

The previous GPS corrected position (starting point of self-sustained running) is A (X _m , Y _m ), the current GPS corrected position is B (X _GPSn , Y _GPSn ), and the self-sustained running position at this time is C (X _n , Y _n ), the absolute azimuth of the straight line connecting the two GPS correction positions is θ _AB , the absolute azimuth of the straight line connecting the previous GPS correction position and the self-supporting position at this time correction is θ _AC , this correction time _Let θ _{n (old) be} the self-sustained azimuth before correction and θ _{n ( new)} be the self-sustained azimuth after correction, then θ _AB and θ _AC are expressed by the following equations.

Θ _AB = tan−1 {(Y _GPSn −Y _m ) / (X _GPSn −X _m )} θ _AC = tan−1 {(Y _n −Y _m ) / (X _n −X _m )} where And m and n (n> m) are arbitrary integers.

Azimuth correction amount calculated from θ _AB and θ _AC
d [theta] is expressed by dθ = {β / (α + β)} × (θ AB -θ AC), thus θ _{n (new)} is represented by the following equation.

Θ _{n (new)} = θ _{n (old)} + dθ Here, the lower limit value of the distance between the two GPS points AB is
L _{AC_min} , the lower limit of the distance between BCs at the time of this correction is L
_{If BC_min} , the distance L between the two GPS points AB
_{When AC} satisfies the following formula, L _AC > L _{AC_min} and the distance between BCs at the time of this correction L _BC satisfies the following formula, L _BC > L _{BC_min} When the corrected azimuth by GPS is effective To correct the traveling direction of the vehicle.

As described above, according to the above-described embodiment, the position is corrected by the GPS every arbitrary time or every arbitrary distance, and the position corrected by the m-th GPS and the n-th GPS are corrected.
Azimuth of the straight line connecting the corrected position by the
The correction amount of the self-supporting traveling azimuth is calculated from the difference between the azimuth of the straight line connecting the position corrected by the GPS correction position and the position of the n-th GPS correction of the self-sustaining travel starting from the correction position by the m-th and n-th GPS. Corrected position is greater than the specified value and nth GPS
If the corrected position by and the autonomous traveling position at the time of the n-th correction are equal to or greater than the specified value, the traveling azimuth of the vehicle can be corrected simultaneously with the n-th position correction.

The azimuth correction amount can be calculated by weighting the GPS azimuth and the self-standing azimuth, and can be gradually converged by repeating the process.

[0024]

As is apparent from the above embodiment, the present invention can automatically determine the vehicle position and the vehicle direction by GPS, so that the driver can determine the initial position and the initial direction of the vehicle in the vehicle-mounted navigation device. This has the effect of eliminating the need for inputting and correcting the current position and current azimuth even after traveling.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing a control flow for correcting the self-sustained travel direction of the device.

FIG. 3 is an explanatory view showing a method of calculating an azimuth calculation means of the same device.

FIG. 4 is a block configuration diagram of a conventional vehicle-mounted navigation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 GPS receiver 2 GPS position calculation means 3 GPS position holding means 4 GPS position absolute azimuth calculation means 5 Speed sensor 6 Speed detection means 7 Moving distance calculation means 8 Angular velocity sensor 9 Independent azimuth change detection means 10 Independent position calculation means 11 Independence Position holding means 12 Absolute azimuth calculation means between self-standing positions 13 Azimuth difference calculation means 14 Independent running azimuth calculation means 15 Running azimuth correction means

Claims (4)

[Claims] 1. G at every arbitrary distance or every arbitrary time
PS position correction is performed, and an inclination of a straight line connecting the m-th GPS corrected position and the n-th GPS corrected position,
An in-vehicle navigation device comprising means for calculating a vehicle azimuth and correcting the vehicle azimuth based on the difference between the inclination of a straight line connecting the self-sustained travel positions at the m-th correction and the n-th correction. 2. The validity of the corrected vehicle azimuth determined by GPS is corrected by correcting the traveling azimuth when the distance between the mth and nth GPS corrected positions is equal to or more than a specified lower limit value. In-vehicle navigation device. 3. The validity of the corrected vehicle azimuth determined by GPS is corrected by correcting the traveling azimuth when the distance between the n-th GPS corrected position and the n-th self-supporting traveling position at the time of correction is not less than a specified lower limit value. The vehicle-mounted navigation device according to claim 1. 4. The vehicle-mounted navigation device according to claim 1, wherein the vehicle azimuth correcting means by GPS is repeatedly weighted a plurality of times and is gradually converged.