JPH09280877A - On-vehicle navigation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle navigation device capable of returning to a right position as quickly as possible even in a case of mismatching to a wrong road and obtaining high accuracy for position and bearing even in a case of off-road running, by always estimating a position of a mobile body with a high accuracy not through map data but by using signals from each sensor of a GPS receiver and a self-contained navigation system and compensating disadvantages of map matching and GPS. SOLUTION: When a heading calculation means 1 calculates a relative bearing, a absolute bearing calculation means 4 converts it into an absolute bearing by using the relative bearing and the GPS bearing outputted by the GPS receiver 3, and a vector calculation means 5 converts into a travel motion vector by using the absolute bearing and a travel distance calculated by a calculation means 2, and an absolute position calculation means 6 integrates the travel motion vector outputted by a vector calculation means 5 to determine an absolute position. Also, when GPS receiver 3 outputs a GPS position, the absolute position calculation means 6 initializes the absolute position by using the GPS position.

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 detecting and displaying a traveling position of a moving body such as an automobile.

[0002]

2. Description of the Related Art Conventionally, a position detecting method using a GPS receiver and a position detecting method (map matching method) for collating a vector calculated based on data obtained from a direction sensor, a vehicle speed sensor, etc. of a self-contained navigation device with road data. As a navigation device for calculating the current position by combining and as required, a device as disclosed in Japanese Patent Laid-Open No. 4-121618 is known.

FIG. 7 shows the structure of a conventional navigation device. Reference numeral 71 calculates position information and velocity vector information of a moving body from the distance between a GPS satellite and a moving body such as an automobile and the rate of change in distance. A GPS receiver, 72 is a wheel speed sensor that measures the speed and distance of the moving body, 73 is a steering angle sensor that measures the rotation angle of the wheels of the moving body, 74 is a gyro, and the steering angle sensor 73 and the gyro 74 are movable. Measure the angle that your body rotates. Reference numeral 75 is a geomagnetic sensor that measures the direction in which the moving body is facing, and these wheel speed sensor 72, rudder angle sensor 73, gyro 74, and geomagnetic sensor 75 function as sensors of the self-contained navigation system.

Reference numeral 76 is a navigation calculation unit for selecting the correct detection means or output from the outputs of the speed detection means and the direction detection means and the speed vector, 77 is a map memory for storing various information such as a road map, and 78 is a map memory 77. It is a display that displays the read map, displays a mark indicating the current position on the map, and displays other information.

The operation of the conventional navigation device thus constructed will be described with reference to the flowchart of FIG.

First, it is checked whether or not three or more GPS satellites are in the visible range and positioning by the GPS receiver 71 is possible.

When positioning by the GPS receiver 71 is possible
In (S2), data is taken in from the GPS receiver 71 and each sensor of the self-contained navigation system (S3). Then, one of the measured values is compared with the immediately preceding measured value, and it is determined whether or not the data can be used depending on whether the measured value has changed by exceeding a certain value determined by the system (S4, S5).

If both measured values are within a fixed value determined by the system, navigation is performed by calculating the average of the two or selecting one of the measured values (S).
6). If either of the two measured values has changed beyond a certain value set by the system, the measured value is determined to be false and navigation is performed using the other data.
(S10, S12).

When positioning by the GPS receiving device 71 is impossible (S2), data is taken in from the sensor of the self-contained navigation system (S11), and the obtained distance information, rotation angle information and azimuth information are output. Yes (S12).

Therefore, the vehicle position is calculated and determined based on any one of the data thus obtained (S7),
By applying the map matching to this calculation result (S8), the own vehicle position can be determined more accurately (S9).

In this way, by using the speed vector information output from the GPS receiving device 71 and the speed information and azimuth information output from the sensor of the self-contained navigation system in combination, navigation is performed, and thus highly accurate positioning is possible. It can be performed.

[0012]

However, in the conventional navigation device, it is not possible to always perform the position calculation processing.
Since there is only a system, there is a problem that it is impossible to constantly monitor the matching position and frequently correct the own vehicle position.

Therefore, in addition to the calculation of the own vehicle position by map matching, the GPS position can be calculated without using the map data.
There has been a demand for means capable of constantly estimating the vehicle position with high accuracy by using signals from the receiving device and the sensors of the self-contained navigation system.

The present invention has been made in order to solve the above problems and requirements, and it is erroneous to make up for the disadvantages of both the map matching having a high road dependency and the GPS receiving device having a low continuity. (EN) Provided is a vehicle-mounted navigation device that promptly returns to a correct position even when matched with a road, and secures high position accuracy and azimuth accuracy even when traveling on a place other than the road.

[0015]

The present invention can be obtained from a traveling azimuth calculating means for calculating a relative azimuth of a moving body such as an automobile from a gyro such as an optical fiber gyro, a piezoelectric vibrating gyro, a semiconductor gyro, and the rotation of wheels. A travel distance calculating means for calculating the travel distance of the moving body using a pulse signal or the like,
Absolute azimuth calculation means for calculating an absolute azimuth using the calculated relative azimuth and the GPS azimuth obtained from the GPS receiver, and vector calculation for calculating a travel vector using the calculated absolute azimuth and the travel distance calculated by the travel distance calculation means. Means and the running vector are integrated to calculate the absolute position, and the GP
When the GPS position is obtained from the S receiver, it is possible to maintain high position accuracy by configuring it with an absolute position calculation means that initializes the absolute position using the GPS position.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the invention described in claim 1 of the invention, a traveling azimuth calculation for calculating a relative azimuth of a moving body such as an automobile from a gyro such as an optical fiber gyro, a piezoelectric vibration gyro, a semiconductor gyro Means, a travel distance calculating means for calculating the travel distance of the moving body using a pulse signal or the like obtained from the rotation of the wheels, a relative bearing calculated by the traveling bearing calculating means, and a GPS bearing output from the GPS receiver. An absolute azimuth calculation means for calculating an absolute azimuth using a vector calculation means for calculating a travel vector using the absolute azimuth calculated by the absolute azimuth calculation means and the mileage calculated by the mileage calculation means; The absolute position is calculated by integrating the calculated traveling vectors, and G
When the GPS position is obtained from the PS receiver, the GPS
With the absolute position calculation means for initializing the absolute position using the position, the GPS receiver continuously receives the data regardless of whether it is received or not, and with high accuracy regardless of the presence or absence of matching map data. , The position of the moving body can be calculated only by the sensor of the self-contained navigation system.

Further, according to the invention described in claim 2, when the GPS position is newly obtained, the G
Absolute position calculation can be performed easily and with high reliability by the absolute position calculation means that sets the midpoint between the PS position and the absolute position at that time as the new absolute position.

Further, according to the invention of claim 3, the accuracy of the relative azimuth and the accuracy of the traveling distance calculated by the traveling azimuth calculating means are calculated, and the accuracy of the relative azimuth and the traveling distance are calculated. By providing a function of calculating the absolute position from the accuracy and the error value of the GPS position and estimating the accuracy of the absolute position, the accuracy of the absolute position can be grasped quantitatively.

Further, according to the invention described in claim 4 of the claims, the absolute position and the GPS position are determined from the ratio of the accuracy of the absolute position calculated by the system according to claim 3 and the accuracy of the GPS position. By providing a function of calculating a position that internally divides the absolute position and updating the absolute position, the absolute position can be calculated with higher accuracy as compared with the method of averaging the GPS position and the absolute position to obtain the midpoint. it can.

Further, according to the invention of claim 5, the absolute position accuracy and the GPS position accuracy are internally divided from the ratio of the absolute position accuracy and the GPS position accuracy, By providing the function of updating the accuracy of the absolute position, the absolute position can be calculated with higher accuracy.

Further, according to the invention described in claim 6, the map matching means for calculating the current position through the map information, and the position and the absolute position of the moving body calculated by the map matching means. When the position is more than the accuracy of the absolute position, by including the position selecting means for correcting the absolute position to the position of the moving body, even when the map matching means makes a mistake in selecting the road, the absolute position and the accuracy are always maintained. Since it is calculated, the absolute position can be corrected only when it is really necessary, regardless of whether the GPS position is measured or not.

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows a configuration of an absolute position calculating means in a first embodiment of the present invention. Reference numeral 1 is a traveling azimuth calculating means, which is a light whose rotational angular velocity or relative angle can be calculated. A gyro such as a fiber gyro, a piezoelectric vibrating gyro, a semiconductor gyro and the like, and a means for integrating a signal from the gyro in an analog or digital manner, and calculates a relative azimuth.

Reference numeral 2 denotes a traveling distance calculating means, which is moved by using a velocity pulse signal obtained by rotation of a wheel multiplied by a distance conversion coefficient or an output of an acceleration sensor which is double integrated while being corrected. Calculate the distance traveled by the body.

Reference numeral 3 denotes a GPS receiver, which is based on the position information and orbit information of GPS satellites (not shown), the position (latitude and longitude) on the earth of a moving body such as an automobile equipped with a receiver and an antenna, and the movement of the moving body. The speed and moving direction (hereinafter referred to as "GPS direction") are output.

Reference numeral 4 denotes an absolute azimuth calculation means. Since the relative azimuth calculated by the traveling azimuth calculation means 1 is an integrated value of the gyro output, it may have an offset with respect to the true traveling azimuth even if the dimension is correct. The relative azimuth calculated by the traveling azimuth calculating means 1 is compared with the GPS azimuth output by the GPS receiver 3 to calculate the azimuth correction value, and the absolute azimuth is calculated by adding the azimuth correction value to the relative azimuth.

Reference numeral 5 denotes a vector calculating means, which determines a traveling vector whose length is the traveling distance and whose absolute orientation is the direction, based on the traveling distance calculated by the traveling distance calculating means 2 and the absolute bearing calculated by the absolute bearing calculating means 4. It is calculated for each running time or fixed distance.

Reference numeral 6 denotes an absolute position calculating means, which orthogonally intersects the latitude and longitude of the initial position 21 (see FIG. 2) determined by the system with the travel vector calculated by the vector calculating means 5 for each constant traveling time or constant distance. The absolute latitude is calculated and updated by sequentially adding the differential latitude and differential longitude decomposed into coordinate components.

The concept of the absolute position calculation processing of the absolute position calculation means in the first embodiment configured as described above is shown in FIG. 2, in which traveling from the initial position 21 calculated by the absolute position calculation means 6 is performed. It is assumed that the vector integration locus, that is, the absolute position locus is as shown by a locus 22.

However, when the absolute position reaches the position 23, the GPS newly obtained by the GPS receiver 3 is obtained.
When the position is the position 24, the absolute position calculation means 6 performs an initialization process of changing the GPS position obtained by the GPS receiver 3, that is, the position 24 to a new initial position, and then a new initial position. Since the running vector integration from 24 is continued, the locus of absolute position thereafter becomes like locus 25 with the initial position being position 24.

(Embodiment 2) The configuration of the absolute position calculating means of the second embodiment of the present invention is the same as that of the first embodiment of the present invention shown in FIG. The azimuth calculating means includes a gyro such as an optical fiber gyro, a piezoelectric vibrating gyro, a semiconductor gyro, etc. capable of calculating the rotational angular velocity or the relative angle, and means for integrating the signal from the gyro in an analog or digital manner to calculate the relative azimuth. To do.

Reference numeral 2 denotes a traveling distance calculating means, which moves by using a velocity pulse signal obtained by rotation of a wheel multiplied by a distance conversion coefficient, or an output of an acceleration sensor which is double integrated while being corrected. Calculate the distance traveled by the body.

Reference numeral 3 denotes a GPS receiver, which is based on the position information and orbit information of GPS satellites (not shown), the position (latitude and longitude) on the earth of a moving body such as an automobile equipped with a receiver and an antenna, and the movement of the moving body. The speed and moving direction (hereinafter referred to as "GPS direction") are output.

Reference numeral 4 denotes an absolute azimuth calculation means, which is the relative azimuth calculated by the traveling azimuth calculation means 1 and the G output by the GPS receiver 3.
After comparing the PS azimuth with the azimuth correction value, the azimuth correction value is added to the relative azimuth to calculate the absolute azimuth.

Reference numeral 5 denotes a vector calculating means, which determines a traveling vector whose length is the traveling distance and whose absolute orientation is the direction, based on the traveling distance calculated by the traveling distance calculating means 2 and the absolute bearing calculated by the absolute bearing calculating means 4. It is calculated for each running time or fixed distance.

Reference numeral 6 denotes an absolute position calculating means, which orthogonally intersects the latitude and longitude of the initial position 31 (see FIG. 3) determined by the system with the travel vector calculated by the vector calculating means 5 for each constant traveling time or constant distance. The absolute latitude is calculated and updated by sequentially adding the differential latitude and differential longitude decomposed into coordinate components.

The concept of the absolute position calculation processing of the absolute position calculation means in the second embodiment configured as described above is shown in FIG. 3, in which traveling from the initial position 31 calculated by the absolute position calculation means 6 is performed. It is assumed that the vector integration locus, that is, the absolute position locus is like a locus 32.

However, when the absolute position reaches the position 33, the GPS newly obtained by the GPS receiver 3 is obtained.
When the position is the position 34, the absolute position calculating means 6 determines the GPS position obtained by the GPS receiver 3, that is, the absolute position.
Initialization processing is performed to change the position 35, which is the midpoint between 33 and position 34, to a new initial position, and the running vector from the new initial position 35 continues to be integrated. It becomes a locus 36 with the initial position being position 35.

(Embodiment 3) FIG. 4 shows the configuration of an absolute position calculating means in a third embodiment of the present invention. Reference numeral 1 is a traveling azimuth calculating means, which is a light whose rotational angular velocity or relative angle can be calculated. A gyro such as a fiber gyro, a piezoelectric vibrating gyro, a semiconductor gyro and the like, and a means for integrating a signal from the gyro in an analog or digital manner, and calculates a relative azimuth.

Reference numeral 3 denotes a GPS receiver which, based on the position information and orbit information of GPS satellites (not shown), the position (latitude and longitude) on the earth of a moving body such as an automobile equipped with a receiver and an antenna, and the movement of the moving body. The speed and moving direction (hereinafter referred to as "GPS direction") are output.

Reference numeral 7 denotes a traveling distance calculating means which moves by using a velocity pulse signal obtained by rotation of the wheel multiplied by a distance conversion coefficient, or an output of the acceleration sensor which is double integrated while being corrected. The distance traveled by the body and a distance error value representing the accuracy thereof are calculated at the same time. This distance error value is
For example, when the distance conversion coefficient is calculated using GPS, the one obtained by multiplying the percentage accuracy of the distance conversion coefficient itself by the traveling distance is used.

Reference numeral 8 denotes an absolute azimuth calculation means, which is the relative azimuth calculated by the traveling azimuth calculation means 1 and the G output by the GPS receiver 3.
The azimuth correction value is calculated by comparing with the PS azimuth, and then the azimuth correction value is added to the relative azimuth to simultaneously calculate the absolute azimuth and the azimuth error value indicating the accuracy. This azimuth error value depends on the accuracy of the GPS azimuth because it is an error value of the relative azimuth, but the accuracy of the GPS azimuth depends on the moving speed. Therefore, the azimuth error value is estimated from the moving speed after calculating the moving speed.

Reference numeral 9 denotes a vector calculating means, which is a traveling vector having a traveling distance as a length and an absolute orientation as a direction, based on the traveling distance calculated by the traveling distance calculating means 7 and the absolute azimuth calculated by the absolute azimuth calculating means 8. A vector error value representing the accuracy is calculated at the same time for each constant traveling time or constant distance. When this calculation is performed, the distance error value and the bearing error value are independent, so the vector error caused by the bearing error is calculated by taking the sine value or tangent value of the bearing error and multiplying that value by the vector length. Then, the simple sum of the vector error value and the distance error value due to the heading error, the square root of the sum of squares, etc. are calculated and output as a vector error value.

Reference numeral 10 is an absolute position calculating means, which is the first or second
The absolute position is calculated and updated like the absolute position calculating means 6 of the embodiment, and the vector error value calculated by the vector calculating means 9 is added to the position error value. When a new GPS is received, this position error value is initialized to the error major axis value that is its accuracy index.

In this way, the absolute position error value representing the accuracy of the absolute position is calculated.

(Embodiment 4) The configuration of the absolute position calculating means of the fourth embodiment of the present invention is the same as that of the third embodiment of the present invention shown in FIG. The azimuth calculating means includes a gyro such as an optical fiber gyro, a piezoelectric vibrating gyro, a semiconductor gyro, etc. capable of calculating the rotational angular velocity or the relative angle, and means for integrating the signal from the gyro in an analog or digital manner to calculate the relative azimuth. To do.

Reference numeral 3 denotes a GPS receiver, which is based on position information and orbit information of GPS satellites (not shown), the position (latitude and longitude) of the moving body such as an automobile equipped with a receiver and an antenna on the earth, and movement of the moving body. The speed and moving direction (hereinafter referred to as "GPS direction") are output.

Reference numeral 7 denotes a traveling distance calculating means, which moves by using a velocity pulse signal obtained by rotation of the wheel multiplied by a distance conversion coefficient or an output of an acceleration sensor which is double integrated while being corrected. The distance traveled by the body and a distance error value representing the accuracy thereof are calculated at the same time. This distance error value is
For example, when the distance conversion coefficient is calculated using GPS, the one obtained by multiplying the percentage accuracy of the distance conversion coefficient itself by the traveling distance is used.

Reference numeral 8 denotes an absolute azimuth calculating means, which is the relative azimuth calculated by the traveling azimuth calculating means 1 and the G output by the GPS receiver 3.
The azimuth correction value is calculated by comparing with the PS azimuth, and then the azimuth correction value is added to the relative azimuth to simultaneously calculate the absolute azimuth and the azimuth error value indicating the accuracy. This azimuth error value depends on the accuracy of the GPS azimuth because it is an error value of the relative azimuth, but the accuracy of the GPS azimuth depends on the moving speed. Therefore, the azimuth error value is estimated from the moving speed after calculating the moving speed.

Reference numeral 9 denotes a vector calculating means, which is a traveling vector having a traveling distance as a length and an absolute orientation as a direction, based on the traveling distance calculated by the traveling distance calculating means 7 and the absolute azimuth calculated by the absolute azimuth calculating means 8. A vector error value representing the accuracy is calculated at the same time for each constant traveling time or constant distance. When this calculation is performed, the distance error value and the bearing error value are independent, so the vector error caused by the bearing error is calculated by taking the sine value or tangent value of the bearing error and multiplying that value by the vector length. Then, the simple sum of the vector error value and the distance error value due to the heading error, the square root of the sum of squares, etc. are calculated and output as a vector error value.

Reference numeral 10 is an absolute position calculating means, which is the first or second
The absolute position is calculated and updated like the absolute position calculating means 6 of the embodiment, and the vector error value calculated by the vector calculating means 9 is added to the position error value. When a new GPS is received, this position error value is initialized to the error major axis value that is its accuracy index.

FIG. 5 shows the concept of the absolute position calculation processing of the absolute position calculation means in the fourth embodiment configured as described above.
The error major axis value indicating the position accuracy of 52 is 100 m, and the absolute position error value of the absolute position 51 obtained at that time is 200
If m, the absolute position is the position 51 and the position 52:
The position 53 is internally divided into 1. After that, until new GPS position data is obtained, the locus of the absolute position becomes like the locus 54 with the initial position being the position 53 by integration of the traveling vector.

(Fifth Embodiment) The configuration of the absolute position calculating means of the fifth embodiment of the present invention is the same as that of the third embodiment of the present invention shown in FIG. The azimuth calculating means includes a gyro such as an optical fiber gyro, a piezoelectric vibrating gyro, a semiconductor gyro, etc. capable of calculating the rotational angular velocity or the relative angle, and means for integrating the signal from the gyro in an analog or digital manner to calculate the relative azimuth. To do.

Reference numeral 3 denotes a GPS receiver, which is based on the position information and orbit information of GPS satellites (not shown), the position (latitude and longitude) on the earth of a moving body such as an automobile equipped with a receiver and an antenna, and the movement of the moving body. The speed and moving direction (hereinafter referred to as "GPS direction") are output.

Reference numeral 7 denotes a traveling distance calculating means, which moves by using a velocity pulse signal obtained by rotation of the wheel multiplied by a distance conversion coefficient, or an output of an acceleration sensor which is double integrated while being corrected. The distance traveled by the body and a distance error value representing the accuracy thereof are calculated at the same time. This distance error value is
For example, when the distance conversion coefficient is calculated using GPS, the one obtained by multiplying the percentage accuracy of the distance conversion coefficient itself by the traveling distance is used.

Reference numeral 8 denotes an absolute azimuth calculating means, which is the relative azimuth calculated by the traveling azimuth calculating means 1 and the G output by the GPS receiver 3.
The azimuth correction value is calculated by comparing with the PS azimuth, and then the azimuth correction value is added to the relative azimuth to simultaneously calculate the absolute azimuth and the azimuth error value indicating the accuracy. This azimuth error value depends on the accuracy of the GPS azimuth because it is an error value of the relative azimuth, but the accuracy of the GPS azimuth depends on the moving speed. Therefore, the azimuth error value is estimated from the moving speed after calculating the moving speed.

Reference numeral 9 denotes a vector calculating means, which is a traveling vector having a traveling distance as a length and an absolute orientation as a direction, based on the traveling distance calculated by the traveling distance calculating means 7 and the absolute azimuth calculated by the absolute azimuth calculating means 8. A vector error value representing the accuracy is calculated at the same time for each constant traveling time or constant distance. When this calculation is performed, the distance error value and the bearing error value are independent, so the vector error caused by the bearing error is calculated by taking the sine value or tangent value of the bearing error and multiplying that value by the vector length. Then, the simple sum of the vector error value and the distance error value due to the heading error, the square root of the sum of squares, etc. are calculated and output as a vector error value.

Reference numeral 10 is an absolute position calculating means, which is the first or second
The absolute position is calculated and updated like the absolute position calculating means 6 of the embodiment, and the vector error value calculated by the vector calculating means 9 is added to the position error value.

The concept of the absolute position calculation processing of the absolute position calculation means in the fifth embodiment configured as described above is shown in FIG. 5. For example, a newly measured GPS position is used.
The error major axis value indicating the position accuracy of 52 is 100 m, and the absolute position error value of the absolute position 51 obtained at that time is 200
If m, the absolute position is the position 51 and the position 52:
The position 53 is internally divided into 1. After that, until new GPS position data is obtained, the locus of the absolute position becomes like the locus 54 with the initial position being the position 53 by integration of the traveling vector.

If the absolute position error value is also calculated by the internal division calculation, the new absolute position error value is 200 m and 1
It is a value that internally divides 00m and 2: 1, that is, 133.3m.

(Sixth Embodiment) The configuration of the absolute position calculating means of the sixth embodiment of the present invention is the same as that of the third embodiment of the present invention shown in FIG. The azimuth calculating means includes a gyro such as an optical fiber gyro, a piezoelectric vibrating gyro, a semiconductor gyro, etc. capable of calculating the rotational angular velocity or the relative angle, and means for integrating the signal from the gyro in an analog or digital manner to calculate the relative azimuth. To do.

Reference numeral 3 denotes a GPS receiver, which is based on the position information and orbit information of GPS satellites (not shown), the position (latitude and longitude) on the earth of a moving body such as an automobile equipped with a receiver and an antenna, and the movement of the moving body. The speed and moving direction (hereinafter referred to as "GPS direction") are output.

Reference numeral 7 denotes a traveling distance calculating means, which moves by using a velocity pulse signal obtained by the rotation of the wheel multiplied by a distance conversion coefficient, or an output of an acceleration sensor which is double integrated while being corrected. The distance traveled by the body and a distance error value representing the accuracy thereof are calculated at the same time. This distance error value is
For example, when the distance conversion coefficient is calculated using GPS, the one obtained by multiplying the percentage accuracy of the distance conversion coefficient itself by the traveling distance is used.

Reference numeral 8 denotes an absolute azimuth calculating means, which is the relative azimuth calculated by the traveling azimuth calculating means 1 and the G output by the GPS receiver 3.
The azimuth correction value is calculated by comparing with the PS azimuth, and then the azimuth correction value is added to the relative azimuth to simultaneously calculate the absolute azimuth and the azimuth error value indicating the accuracy. This azimuth error value depends on the accuracy of the GPS azimuth because it is an error value of the relative azimuth, but the accuracy of the GPS azimuth depends on the moving speed. Therefore, the azimuth error value is estimated from the moving speed after calculating the moving speed.

Reference numeral 9 denotes a vector calculating means, which is a traveling vector having a traveling distance as a length and an absolute orientation as a direction, based on the traveling distance calculated by the traveling distance calculating means 7 and the absolute azimuth calculated by the absolute azimuth calculating means 8. A vector error value representing the accuracy is calculated at the same time for each constant traveling time or constant distance. When this calculation is performed, the distance error value and the bearing error value are independent, so the vector error caused by the bearing error is calculated by taking the sine value or tangent value of the bearing error and multiplying that value by the vector length. Then, the simple sum of the vector error value and the distance error value due to the heading error, the square root of the sum of squares, etc. are calculated and output as a vector error value.

Reference numeral 10 is an absolute position calculating means, which is the first or second
The absolute position is calculated and updated like the absolute position calculating means 6 of the embodiment, and the vector error value calculated by the vector calculating means 9 is added to the position error value.

The concept of the absolute position calculation processing of the absolute position calculation means in the sixth embodiment configured as described above is shown in FIGS. 5 and 6, and for example, a newly positioned G
If the error major axis value indicating the position accuracy of the PS position 52 is 100 m and the absolute position error value of the absolute position 51 obtained at that time is 200 m, the absolute positions are the positions 51 and 52.
The position 53 is obtained by internally dividing and 2: 1. Then a new G
Until the PS position data is obtained, the trajectory of the absolute position is the trajectory whose initial position is the position 53 by integrating the travel vector.
It looks like 54.

If the absolute position error value is also calculated by the internal division calculation, the new absolute position error value is 200 m and 1
It is a value that internally divides 00m and 2: 1, that is, 133.3m.

In this way, the vehicle always travels while calculating and updating the absolute position and its accuracy, but as shown in FIG.
It is assumed that the mobile body is actually traveling on the road 61, but the map matching process makes an error in selecting the road at the branch 62 or the like and the vehicle position 64 is calculated toward the road 63.

In the map matching process, the absolute position 65 calculated by the absolute position calculating means 10 and the absolute position error value R representing the accuracy thereof are constantly monitored. Therefore, the calculated vehicle position 64 is centered on the absolute position 65. If it is determined that the vehicle is outside the circle having the radius R, the vehicle position is immediately corrected to the absolute position 65, and the traveling process is continued.

Even if the actual moving body is traveling on the road, the absolute position 65 does not always exist on the road because it has an error, but inside the circle of radius R centering on the absolute position 65. The vehicle position may be initialized on the road 66 (link) closest to the absolute position 65, and the map matching may be restarted from there.

[0072]

As described above, according to the invention described in claim 1, the relative azimuth of a moving body such as an automobile is calculated from a gyro such as an optical fiber gyro, a piezoelectric vibration gyro, and a semiconductor gyro. The traveling azimuth calculating means, the traveling distance calculating means for calculating the traveling distance of the moving body using the pulse signals obtained from the rotation of the wheels, the relative azimuth calculated by the traveling azimuth calculating means, and the output from the GPS receiver. An absolute azimuth calculation unit that calculates an absolute azimuth using the GPS azimuth, and a vector calculation unit that calculates a travel vector using the absolute azimuth calculated by the absolute azimuth calculation unit and the mileage calculated by the mileage calculation unit; When the absolute position is calculated by accumulating the traveling vectors calculated by the vector calculating means and the GPS position is obtained from the GPS receiver, the GPS position is calculated. By using the absolute position calculating means for initializing the absolute position by using the GPS receiver, the GPS receiver can continuously operate regardless of reception or non-reception, and with high accuracy regardless of presence or absence of matching map data. It is possible to calculate the position of the moving body using only the sensor of the navigation system.

According to the invention described in claim 2, when the GPS position is newly obtained, the G
With the absolute position calculating means that sets the midpoint between the PS position and the absolute position at that time as the new absolute position, the absolute position can be simply updated with high reliability.

Further, according to the invention of claim 3, the accuracy of the relative azimuth and the accuracy of the traveling distance calculated by the traveling azimuth calculating means are calculated, and the accuracy of the relative azimuth and the traveling distance are calculated. Since the absolute position is calculated from the accuracy and the error value of the GPS position and the accuracy of the absolute position is estimated, the accuracy of the absolute position can be grasped quantitatively.

Further, according to the invention described in claim 4, the absolute position and the GPS position are calculated from the ratio of the accuracy of the absolute position calculated by the system of claim 3 and the accuracy of the GPS position. By providing a function of calculating a position that internally divides the absolute position and updating the absolute position, the absolute position can be calculated with higher accuracy as compared with the method of averaging the GPS position and the absolute position to obtain the midpoint. It has the effect of being able to.

Further, according to the invention of claim 5, the absolute position accuracy and the GPS position accuracy are internally divided from the ratio of the absolute position accuracy and the GPS position accuracy, By providing the function of updating the accuracy of the absolute position, it is possible to calculate the absolute position with higher accuracy.

Further, according to the invention described in claim 6, the map matching means for calculating the current position through the map information, and the position and the absolute position of the moving body calculated by the map matching means. When the position is more than the accuracy of the absolute position, by including the position selecting means for correcting the absolute position to the position of the moving body, even when the map matching means makes a mistake in selecting the road, the absolute position and the accuracy are always maintained. Since it is calculated, there is an effect that the absolute position can be corrected only when it is really necessary, regardless of whether the GPS position is measured or not.

As described above, according to the present invention, by comparing the absolute position obtained by this method with the position of the moving body obtained by using the conventional map matching means, the map matching means can detect the wrong road. Even when aligning the position of the moving body, an opportunity is always given to correct the position of the moving body to the absolute position, so that a navigation device with high position accuracy can be realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an absolute position calculating means according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a concept of an absolute position calculation process of an absolute position calculation means in the first embodiment of the present invention.

FIG. 3 is a diagram showing a concept of an absolute position calculation process of an absolute position calculation means according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of an absolute position calculating means according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a concept of an absolute position calculation process of absolute position calculation means in the fourth, fifth and sixth embodiments of the present invention.

FIG. 6 is a diagram showing a concept of absolute position calculation processing of an absolute position calculation means in a sixth embodiment of the present invention.

FIG. 7 is a configuration diagram of a conventional navigation device.

FIG. 8 is a flowchart of the conventional example of FIG.

[Explanation of symbols]

1 ... advancing direction calculating means, 2, 7 ... running distance calculating means,
3 ... GPS receiver, 4, 8 ... Absolute direction calculation means,
5, 9 ... Vector calculating means, 6, 10 ... Absolute position calculating means.

Claims (6)

[Claims] 1. A traveling azimuth calculating means for calculating the relative azimuth of a moving body such as an automobile from a gyro such as an optical fiber gyro, a piezoelectric vibration gyro, a semiconductor gyro, etc., and the movement using a pulse signal or the like obtained from the rotation of wheels. A travel distance calculation means for calculating a travel distance of the body; an absolute azimuth calculation means for calculating an absolute azimuth using the relative azimuth calculated by the traveling azimuth calculation means and the GPS azimuth output from the GPS receiver; A vector calculation means for calculating a travel vector using the absolute azimuth calculated by the azimuth calculation means and the travel distance calculated by the travel distance calculation means, and an absolute position is calculated by integrating the travel vector calculated by the vector calculation means. However, when the GPS position is obtained from the GPS receiver, an absolute position calculation method for initializing the absolute position using the GPS position. Vehicle navigation device equipped with a door. 2. When the new GPS position is obtained from the GPS receiver, the absolute point between the GPS position and the absolute position calculated by the absolute position calculation means is the new absolute position. The vehicle-mounted navigation device according to claim 1, further comprising position calculating means. 3. The absolute azimuth calculating means for calculating the accuracy of the relative azimuth calculated by the traveling azimuth calculating means, the mileage calculating means for calculating the accuracy of the calculated mileage, the relative azimuth accuracy, the The vehicle-mounted navigation device according to claim 1, further comprising: the absolute position calculating means for estimating the accuracy of the absolute position calculated from the error long axis value representing the error value of the GPS position during positioning and the accuracy of the mileage. 4. The absolute position calculating means for calculating a position that internally divides the absolute position and the GPS position from the ratio of the error major axis value and the accuracy of the absolute position, and updating the absolute position. The vehicle-mounted navigation device according to claim 3, further comprising: 5. The position for internally dividing the accuracy of the absolute position and the accuracy of the GPS position is calculated from the ratio of the error major axis value and the accuracy of the absolute position, and the accuracy of the absolute position is updated. The vehicle-mounted navigation device according to claim 4, further comprising an absolute position calculation means. 6. A map matching means for calculating a current position based on map information, and the absolute position when the position of the moving body and the absolute position calculated by the map matching means are apart from each other by an accuracy of absolute position or more. The vehicle-mounted navigation device according to claim 5, further comprising: a position selecting unit that corrects the position of the vehicle to the position of the moving body.