JPH0755480A - Navigation apparatus - Google Patents

Abstract

PURPOSE:To determine the present position, the advance direction, the running velocity and the like by estimating with good accuracy by a method wherein, when the positioning state by a GPS is bad, data is changed over to data by an angular-velocity sensor and a distance sensor and the data is corrected by a newest corrected value. CONSTITUTION:When the positioning state by a GPS is good and the vehicle velocity is at a prescribed set value or higher, data is changed over to data by the GPS, and the angle and the traveling velocity which have been computed on the basis of outputs from a vibrating gyro 24 and a distance sensor 23 are corrected by received data from the GPS and stored in a RAM 25h. In addition, when the positioning state by the GPS is bad or when the traveling velocity becomes a low velocity at the prescribed set value or lower, the data by the GPS is changed over to data by the vibrating gyro 24 and the distance sensor 23, the data by the vibrating gyro 24 and the distance sensor 23 is corrected by a newest correction value which has been stored in the RAM 25h, and a present position, the present traveling direction and the traveling velocity are estimated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation device capable of accurately estimating and obtaining a current position, a traveling direction, a speed and the like.

[0002]

2. Description of the Related Art FIG. 11 is a block diagram showing a conventional navigation device. In the figure, 1 is an angular velocity sensor (vibration gyro). FIG. 12 is a structural diagram of the angular velocity sensor (vibration gyro). The detection piezoelectric ceramics 3a and the detection piezoelectric ceramics 4a are arranged on the side surfaces 3 and 4 of the triangular prism vibrator 2, respectively, and the other side surface 5 is arranged. It is composed of the returned piezoelectric ceramic 5a, and detects and outputs the rotation angle information of the vehicle.

Reference numeral 6 is a distance sensor which outputs a pulse signal according to the amount of movement of the vehicle. A CD-ROM 7 stores map information and the like. Reference numeral 8 is a CD-ROM player for reading out map information and the like stored in the CD-ROM 7, reference numeral 9 is a data receiving section for receiving data by GPS, and 1
Reference numeral 1 denotes a process for obtaining the current position and the traveling direction of the own vehicle based on the angular velocity information of the vehicle output from the angular velocity sensor (vibration gyro) 1 and the distance information output from the distance sensor 6, and the data receiving unit 9 receives the data. It is a CPU that executes processing for obtaining the current position of the vehicle, the current traveling direction, and the like, based on the data obtained by the GPS. Reference numeral 12 denotes a display, which displays the map information stored in the CD-ROM 7 and the obtained current position of the own vehicle in an overlapping manner.

Next, the operation will be described. In this navigation device, the G received by the normal data receiving unit 9 is used.
The current position of the own vehicle is measured based on the PS data, and the measured current position is displayed on the display 12 together with the map information stored in the CD-ROM 7. Further, in a tunnel where GPS data cannot be sufficiently received, directly under a high-rise building, or on a road constructed underground, the angular velocity sensor (vibration gyro) 1 outputs the rotation angle information of the vehicle and the distance sensor. The present position of the own vehicle is obtained from the vehicle speed information output from 6 and displayed on the display.

[0005]

Since the conventional navigation device is constructed as described above, the accuracy of position detection of the own vehicle when GPS data cannot be sufficiently received is determined by the angular velocity sensor (vibration gyro). It depends on the detection accuracy of the rotational angular velocity information of 1 and the vehicle speed information of the distance sensor 6.

In this case, the vibration gyro 1 must be appropriately processed in consideration of the drift of the vibration gyro itself and the drift of the processing circuit of the voltage signal output from the piezoelectric ceramics 3a and 4a for detecting the vibration gyro. There is a problem. Furthermore, there is a problem in that the sensitivity of the vibration gyro itself varies depending on the vibration gyro.

Further, there is a problem that the number of pulses output from the distance sensor when the tire makes one rotation is different due to the structural difference depending on the vehicle type. In addition, the size of the tire differs from vehicle to vehicle, and the amount of movement of the vehicle per pulse varies depending on the road surface condition, tire pressure, and the presence or absence of slip, which causes problems such as the vibration gyro 1 and the distance sensor. Since the output of 6 includes an error and a variation, the detection accuracy of the current position of the vehicle is not constant according to it, and there is a problem that the detection accuracy deteriorates.

The present invention has been made to solve the above problems, and accurately estimates the current position, the traveling direction, the traveling speed, etc. even in a situation where the positioning state by GPS is poor. The purpose is to obtain a navigation device that can be obtained by.

[0009]

A navigation device according to a first aspect of the present invention receives GPS data, performs positioning based on the received data, or detects angle information and a distance sensor detected by an angular velocity sensor. In a navigation device that estimates the current position, current traveling direction, and traveling speed based on traveling speed information,
When the positioning by PS is good and the traveling speed is equal to or higher than a predetermined speed, the data obtained by the angular velocity sensor and the distance sensor are used to obtain the data obtained by the GPS.
The speed and the traveling speed estimated based on the outputs of the angular velocity sensor and the distance sensor.
The correction is performed for each data that satisfies the predetermined condition received from S, and the latest correction value is stored. On the other hand, when the positioning state by the GPS becomes poor, or when the traveling speed becomes lower than a predetermined traveling speed, the data by the GPS is switched to the data by the angular velocity sensor and the distance sensor. At the same time, the data obtained by the angular velocity sensor and the distance sensor are corrected by the latest correction value to estimate the current position, the current traveling direction, and the traveling speed.

A navigation device according to the second invention is
When the positioning state by GPS is poor, the data by GPS is switched to the angle information detected by the angular velocity sensor and the traveling speed information detected by the distance sensor,
In a navigation device that estimates the current position, the current traveling direction, and the traveling speed, the latest position data and the latest azimuth data that continuously satisfy a predetermined condition are used as the position and traveling direction when the positioning state by GPS is good. Set to the standard value. The set reference value is sequentially updated based on the GPS data. When the positioning state by GPS is poor, the current position, the current traveling direction, and the traveling speed are estimated and obtained based on the updated reference value and the outputs of the distance sensor and the angular velocity sensor.

A navigation device according to a third invention is
When the positioning state by GPS is poor, the data by GPS is switched to the angle information detected by the angular velocity sensor and the traveling speed information detected by the distance sensor,
In a navigation device that estimates the current position, the current traveling direction, and the traveling speed, the latest position data and the latest azimuth data that continuously satisfy a predetermined condition when the positioning state by GPS is good are displayed as the position and traveling direction. Set as a reference value. The set reference value is sequentially updated based on the GPS data. When the positioning state by GPS is poor, data such as the current position, the current traveling direction, and the traveling speed are estimated and obtained based on the updated reference value and the outputs of the distance sensor and the angular velocity sensor. A distance conversion constant that defines the distance per pulse of the pulse output by the distance sensor is calculated from the pulse output according to the speed data by the GPS and the traveling distance when the positioning state by the GPS is good. Ask. The calculated distance conversion constant is corrected by averaging the two old and new distance conversion constants.

A navigation device according to a fourth invention is
When the positioning by GPS is poor, the GPS data is switched to the angle information detected by the vibration gyro and the traveling speed information detected by the distance sensor,
In a navigation device that estimates the current position, the current traveling direction, and the traveling speed, the latest position data and the latest azimuth data that continuously satisfy a predetermined condition when the positioning state by GPS is good are displayed as the position and traveling direction. Set as a reference value. The set reference value is sequentially updated based on the GPS data. When the positioning state by the GPS is poor, the current position, the current traveling direction, the traveling speed, etc. are estimated based on the updated reference value, the output of the distance sensor and the output of the vibration gyro. A distance conversion constant that defines the distance per pulse of the pulse output by the distance sensor is calculated from the pulse output according to the speed data by the GPS and the traveling distance when the positioning state by the GPS is good. Ask. The calculated distance conversion constant is corrected by averaging the two old and new distance conversion constants. The average value of a predetermined number of change angle data output by the vibration gyro provided that the variation of the change angle data output by the vibration gyro is within a certain range when the traveling speed is zero. Is calculated as the offset amount of the vibration gyro. Further, the drift of the offset amount is corrected by sequentially updating.

A navigation device according to a fifth invention is
When the positioning state by GPS is poor, the GPS data is switched to the angle information detected by the vibration gyro and the traveling speed information detected by the distance sensor to estimate the current position, traveling direction and traveling speed. When the positioning state is good, the latest position data and the latest azimuth data that continuously satisfy the predetermined condition are set as the reference values of the position and the traveling direction. The set reference value is sequentially updated based on the GPS data. When the positioning state by the GPS is poor, the current traveling direction of the current position, the traveling speed, etc. are estimated based on the updated reference value and the output of the distance sensor and the output of the vibration gyro. A distance conversion constant that defines the distance per pulse of the pulse output by the distance sensor is calculated from the pulse output according to the speed data by the GPS and the traveling distance when the positioning state by the GPS is good. Ask. The calculated distance conversion constant is corrected by averaging the two old and new distance conversion constants. The average of a predetermined number of changing angle data output by the vibration gyro is provided on condition that the variation of the changing angle data output by the vibration gyro is within a certain range when the traveling speed is zero. The value is obtained as the offset amount of the vibration gyro. Further, the drift of the offset amount is corrected by sequentially updating. The sensitivity characteristic of the vibrating gyro is corrected based on the amount of angular change obtained by the GPS and the amount of angular change obtained by the vibrating gyro when the vehicle turns during traveling.

[0014]

The navigation device according to the first invention is
When the positioning state by PS is good and the traveling speed of the moving body is equal to or higher than a predetermined speed, for example, several Km / h or more at which the error of positioning data by GPS is negligible,
Data from the angular velocity sensor and distance sensor to GPS
To switch to the data. At the same time, the angular velocity and the traveling speed are estimated based on the outputs of the angular velocity sensor and the distance sensor and corrected by the data received from the GPS for each predetermined condition, and the latest correction value is stored in a memory such as a RAM. deep. On the other hand, when the positioning state by the GPS becomes poor, or when the traveling speed becomes lower than a predetermined set speed, the data by the GPS is switched to the data by the angular velocity sensor and the distance sensor. .
However, the current position, the current direction, and the current traveling speed are estimated by correcting the data obtained by the angular velocity sensor and the distance sensor based on the latest correction value stored in the memory.

The navigation device according to the second invention is
When the positioning state by GPS is good, the latest position data and latest azimuth data that continuously satisfy the predetermined conditions are set as the reference for the position and the traveling direction and are sequentially updated, and the positioning state by GPS is poor. Then, using the updated reference value, the output of the distance sensor and the output of the angular velocity sensor, the current position, the current traveling direction, the current traveling speed, etc. are accurately estimated.

In the navigation device according to the third aspect of the present invention, the distance conversion constant used for estimating the current position, the current traveling direction, the current speed, etc. when the positioning state by the GPS is poor is determined by the positioning state by the GPS. It is sometimes calculated and corrected from the speed data obtained by the GPS and the pulse indicating the traveling distance. The current position, the current traveling direction, the current speed, etc. when the positioning state by the GPS becomes poor are accurately estimated by using the distance conversion constant.

In the navigation device according to the fourth aspect of the invention, when the traveling speed is zero, the average value of the change angle data output by the vibrating gyro within a predetermined number of fixed ranges is used as the offset of the vibrating gyro. The offset amount is calculated and the drift amount of the offset amount is corrected by sequentially updating the offset amount, thereby eliminating the error cause included in the output of the vibration gyro, and the current state when the positioning state by GPS becomes poor. Position, current direction of travel,
Estimate the current speed with high accuracy.

A navigation device according to a fifth aspect of the present invention corrects the sensitivity characteristic of the vibration gyro according to the difference between the direction change amount obtained by GPS and the angle change amount obtained by the vibration gyro when turning during traveling. By doing so, the current position when the GPS data becomes unusable, the current traveling direction, the current speed, etc. are accurately estimated.

[0019]

【Example】

Example 1. Embodiment 1 of the first invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the navigation device of this embodiment. In the figure, 21 is a GPS receiving antenna, and 22 is a GPS receiver. A distance sensor 23 outputs a pulse signal according to the amount of movement of the vehicle. Reference numeral 24 is a vibrating gyroscope, the structure of which is the same as that shown in FIG.

Reference numeral 25 is an estimation unit, which includes the vibrating gyro 24. In this guessing unit 25, G
The PS data is input from the GPS receiver 22. Further, the current position and direction, and further the traveling speed and the like are estimated and calculated from the outputs of the vibration gyro 24 and the distance sensor 23.

FIG. 2 is a block diagram showing the structure of the estimation unit 25. 25a is a PCB board of the estimation unit 25, 25b is an oscillator, 25c is a CPU, 25d is an interface circuit for pulse signals output from the distance sensor 23, 25e is a storage unit, which includes a ROM 25g and a RAM 2
It has 5h. 25f is a power supply circuit for supplying stabilized DC power.

Returning to FIG. 1, 26 is a data switching means for performing the following operation. That is, when GPS data can be received, the positioning state is good, and the vehicle speed is equal to or higher than a predetermined set value, for example, 5 km / h, the GPS is used.
While switching to the data according to, the angle and traveling speed calculated based on the outputs of the vibration gyro 24 and the distance sensor 23 are corrected every second by the data received from the GPS.
The latest correction value is stored in the RAM 25h. On the other hand, when the reception of data by the GPS is abnormal and the positioning state becomes poor, or when the traveling speed becomes a low speed of a predetermined set value, for example, 5 km / h or less, the GPS is
The data by the vibration gyro 24 and the distance sensor 23 are changed over, and the data by the vibration gyro 24 and the distance sensor 23 are corrected by the latest correction value stored in the RAM 25h. This is to estimate the current position, current running direction, and running speed.

Reference numeral 27 is a car navigation execution unit,
The data output from the estimation unit 25 is processed and the traveling direction of the vehicle is displayed on the display device 28 or the current position is displayed on the map by latitude and longitude.

Next, the operation of the data switching means 26 will be described. FIG. 3 is a flow chart for explaining the operation of the data switching means 26. First, step ST1
At, it is determined from the data from the GPS receiver whether or not the positioning by GPS is good. When it is determined that the positioning by the GPS is not good, the process proceeds to step ST3, the data is switched to the vibration gyro 24 and the distance sensor 23, and the correction value corrected by the GPS data before the switching is read from the RAM 25h to determine the distance from the vibration gyro 24. The data from the sensor 23 is sequentially switched to the data corrected by the correction value, and the estimated data is output to the car navigation execution unit 27.

On the other hand, when it is determined in step ST1 that positioning by GPS is good, step ST2
Then, it is determined whether or not the vehicle speed obtained based on the pulse signal output from the distance sensor 23 is a predetermined set value, for example, 5 km / h or less. When it is determined that the vehicle speed is less than or equal to the predetermined set value of 5 km / h, the process proceeds to step ST3. Also,
When it is determined in step ST2 that the vehicle speed is equal to or higher than the predetermined set value of 5 km / h, the process proceeds to step ST4.
Switch to GPS data from PS receiver,
The data output to the car navigation execution unit 27 and the angle by the vibration gyro 24 and the distance sensor 23,
The traveling speed is corrected by GPS data every one second, and the latest correction value is stored in the RAM 25h.

Example 2. FIG. 4 shows the second embodiment of the second invention.
3 is a block diagram showing the navigation device of FIG. 4, parts that are the same as or equivalent to those in FIG. 1 are given the same reference numerals and explanations thereof are omitted.

In the figure, reference numeral 30 is a reference value setting means, which obtains a reference position such as latitude and longitude and a reference traveling direction from GPS data when the positioning by GPS is good. The reference values such as the reference position and the reference traveling direction obtained by the reference value setting means 30 are sequentially updated by the updating means 31 when the GPS positioning state is good. At this time, (1) The satellite reception condition must be good. (2)
Dop (Dilu
The value of the “ion of Precision” should be within a predetermined set value at a stage of good accuracy. (3) Positioning accuracy is G
It is related to the accuracy being changed on the PS satellite side, and that the accuracy level should be within a predetermined set value at a level of good accuracy. (4) The GPS speed data must be a predetermined value (for example, several Km / h) or more. (5) The difference between the GPS speed data one second before and the latest GPS speed data is within a predetermined set value (for example, 2 km / h). (6) G one second ago
The difference between the PS azimuth data and the latest GPS azimuth data must be within a preset value (for example, 2 °). (7) The change in angle detected by the vibration gyro is a preset value (for example, 1 °)
A reference value setting condition such as being within the range is used. Then, the latest position data satisfying all of the standard setting conditions (1) to (7) at least several times in succession is set as the reference position such as latitude and longitude, and the latest direction data is set as the reference traveling direction.

The estimating unit 25, when the positioning state by GPS is poor, the reference position data obtained by the reference value setting unit 30 and the reference traveling direction are successively updated by the updating unit 31, and the distance sensor 23. Based on the number of pulse signals output from and the output of the vibration gyro 24,
Estimate the current position, current direction of travel, and running speed.

Example 3. FIG. 5 shows the third embodiment of the third invention.
3 is a block diagram showing the navigation device of FIG. 5, parts that are the same as or correspond to those in FIG. 4 are assigned the same reference numerals and explanations thereof are omitted.

In the figure, reference numeral 32 is a distance conversion constant calculating means, which is a distance conversion constant dL (m / pulses) based on the GPS speed data and the pulse signal output from the distance sensor 23 when the positioning by GPS is good. To calculate. The distance conversion constant calculation means 32 is stored in the ROM 25g of the storage unit 25e of the estimation unit 25 as a calculation program. The calculation result of the distance conversion constant calculation means 32 is RA.
It is stored in M25h.

The distance conversion constant dL is a GPS value satisfying the reference value setting conditions (1) to (7) at least several times in succession.
The speed data and the pulse signal output from the distance sensor 23 during the speed data are calculated by the following equation (1).
However, it is preferable that the GPS speed data of the reference value setting condition (4) is, for example, 40 km / h or more.

DL = C1 × (ΣVg / Σp) (1)

However, C1 is a constant (1 / 3.6) for converting the speed unit Km / h into m / s, ΣVg is the GPS speed data integrated value (Km / h), and Σp is the distance sensor 23. It is the integrated value of the pulse signal output from. The number of times of data integration is initially several times, but the number of times of data integration after the second time is preferably more severe than the initial number, and is, for example, about twice. The reference value setting conditions (1) to (7)
Must be established continuously for the data integration period.

Reference numeral 33 denotes a distance conversion constant correcting means, which is the latest distance conversion constant dL (new) calculated by the distance conversion constant calculating means 32 and the distance conversion constant dL (old) which has already been calculated. In order to correct the average value of (1) to a new distance conversion constant dL, the calculation according to the following equation (2) is performed.

{DL (new) + dL (old)} / 2 (2)

This distance conversion constant correction is for improving the conversion accuracy when converting the unit pulse into the distance. The distance conversion constant correction means 33 is stored as a calculation program in the ROM 25g of the storage unit 25e of the estimation unit 25.

Using this distance conversion constant dL, the moving distance L
In order to obtain, the number p of pulse signals output from the distance sensor 23 in one second is multiplied by the distance conversion constant dL, which can be obtained by the following equation (3).

L = p × dL (3)

L is the moving distance (m) of the car per second,
p is the number of pulses output from the distance sensor in 1 second.

When the speed Vn is calculated, the moving distance L of the vehicle for 1 second is divided by the time dt (1 second), so that it can be obtained by the following equation (4).

Vn = C2 × (L / dt) (4)

Here, dt is a time of 1 second, and C2 is a constant (3.6) for converting the speed unit m / s into Km / h. Further, the average value of the two newest speed data is obtained by the following equation (5), and the final speed V (Km /
h).

V = {V (new) + V (old)} / 2 (5)

Note that V (new) is the latest speed data and V (old) is the previous speed data. When the speed data V is zero, the vehicle speed is zero and the speed data V
If is zero for two or more consecutive times, the operation is stopped.

The equations (3), (4) and (5) described above are stored in the ROM 2 of the storage unit 25e of the estimation unit 25.
It is stored in 5g as a calculation program.

Example 4. FIG. 7 shows a fourth embodiment of the fourth invention.
3 is a block diagram showing the navigation device of FIG. In FIG. 7, parts that are the same as or correspond to those in FIGS. 1 and 5 are given the same reference numerals and description thereof is omitted.

Vibration gyro 2 in estimation unit 25
The detection of the change angle of the vehicle by 4 will be described. This change angle is detected, for example, for 1 second (5
(0 data) The output of the vibration gyro 23 is sampled, and the change angle per second is obtained from the integrated value.

That is, assuming that the A / D-converted value of the output of the vibration gyro 24 for every 20 msec is Jn, the integrated value a of the A / D-converted output of the vibration gyro 24 for one second is calculated by the following equation (6). Desired.

A = J ₁ + J ₂ + ... + Jn (n = 50) (6)

In the figure, reference numeral 34 is an offset / drift correction means. This offset / drift correction means 3
At 4, the offset amount of the vibration gyro 24 and its drift are corrected.

The vibration gyro change angle bn per second detected by the vibration gyro 24 is such that when α is the offset amount of the vibration gyro 24, when (a-α) is positive, the angle change in the CW direction (a -Expressed as α) × K1. When (a-α) is negative, it is expressed as (a-α) × K2 in angle change in the CCW direction. Formula (a-α)
The change angle b is the value of the angle change obtained by the calculation of × K1 and the calculation formula (a−α) × K2. Here, K1 and K2 are angle conversion constants of the vibration gyro 24. Expression (6) and an arithmetic expression (a-α) × K1, CCW for obtaining an angle change in the CW direction
The calculation formula (a-α) × K2 for calculating the angle change in the direction is shown in FIG.
It is stored as a calculation program in the ROM 25g of the estimation unit 25 shown in FIG. Also, these vibrating gyros 2
The offset amount α of 4 and the initial values of the angle conversion constants K1 and K2 are stored in the ROM 25g. The calculation results of the equation (6), the arithmetic expression (a-α) × K1, and the arithmetic expression (a-α) × K2 are stored in the RAM 25h.

The change angle b is obtained as the change angle B by substituting the latest value into the following equation (7).

B = {b (new) + b (old)} / 2 (7)

Here, the value of b (new) indicates the latest value of the change angle b, and the value of b (old) indicates the value of the change angle b one second before.

When the latest variations of the changing angle b values are within ± 0.1 ° when the vehicle is stopped, the average of the changing angle b values (moving average) is used. ) Then, the vibration gyro 24 is obtained as an offset amount α. Further, this offset amount α is sequentially updated as long as the above condition is satisfied.

Next, when positioning of the current position, current traveling direction, current speed, etc. using GPS data becomes impossible, the current position, traveling direction, current speed, etc. performed in the estimation unit 25. The inference calculation of will be described. This estimated calculation is based on the moving distance L (m) for 1 second.
Change angle B, reference value setting means 30 and updating means 31
The reference position such as latitude and longitude and the reference traveling direction φ obtained by The estimated value θ in the traveling direction is estimated and calculated by an arithmetic expression of θ = B + φ.

Further, if the distance per minute of latitude is 1852 m, the estimated position such as latitude and longitude can be obtained by the following equation (8) for the estimated latitude value Y.

Y = Y0 + (L × cos θ) / ε (8)

Here, Y0 is the latitude of the reference position obtained by the reference value setting means 30 and the updating means 31, and ε is a latitude conversion constant of 1852 m.

Further, the longitude estimated value X is obtained by the following equation (9).

X = X0 + (L × sin θ) / η ·· (9)

Here, X0 is the longitude of the reference position obtained by the reference value setting means 30 and the updating means 31, η is a longitude conversion constant, and the distance per 1 minute of latitude is 1852 m.
Then, the longitude conversion constant η is calculated and calculated from 1852 m × cos (north latitude Y °), and is configured as a table shown in FIG. For the fractional latitude and longitude generated during the position estimation calculation, the error shall not be accumulated in addition to the next calculation.

Example 5. FIG. 8 is a fifth embodiment of the fifth invention.
3 is a block diagram showing the navigation device of FIG. 8, parts that are the same as or correspond to those in FIGS. 1 and 7 are given the same reference numerals, and descriptions thereof will be omitted.

In the figure, numeral 35 is a sensitivity characteristic correction means for comparing the azimuth change data by GPS and the change angle by the vibration gyro 24 and automatically correcting the angle conversion constant of the vibration gyro 24.

A method of correcting the angle conversion constant performed by the sensitivity characteristic correction means 35 will be described with reference to the flowchart shown in FIG. FIG. 9 shows the angle conversion constant K in the CW direction.
It is a flow chart which shows the correction processing of 1. First, the reference value setting condition in the reference value setting means already described, that is, (1) the satellite reception state is good. (2) Dopp (Dilut) showing the accuracy level depending on the satellite arrangement
The ion of Precision value should be within a predetermined set value at a stage of almost accurate accuracy. (3) Positioning accuracy is GP
It is related to the fact that the accuracy is changed on the S satellite side, and that the accuracy level falls within a predetermined set value at a level of good accuracy.
(4) GPS speed data is a predetermined set value (for example, several km
/ H) or more. (5) The difference between the GPS speed data one second before and the latest GPS speed data is within a predetermined set value (for example, 2 km / h). (6) GP one second ago
The difference between the S azimuth data and the latest GPS azimuth data must be within a predetermined set value (for example, 2 °). (7) Conditions such that the angle change detected by the vibration gyro is within a predetermined set value (for example, 1 °), and these (1) to (7)
Azimuth change data Φ0 immediately before turning that satisfies the reference setting condition of at least several times in succession and azimuth change data Φ1 immediately after turning that satisfies the reference value setting condition within 30 seconds after turning (step ST11), then Φ0-Φ1
Is calculated to obtain the change angle Φ by the GPS (step ST12), and the change angle integrated value Ψ (Ψ = Σbn, where n is up to 29, when n = 0, immediately before turning when the vibration gyro 24 is present. Angle value when azimuth change data Φ0 is set, and when n is other than 0, change angle value when azimuth change data Φ1 immediately after turning is set) is detected (step ST13), where Φ is 60 °. Correction data dK1 when within the range of 180 °
From K1 × (Φ / Ψ) (step ST14), and the angle conversion constant K1 in the CW direction is corrected by the equation K1 = (K1 + dK1) / 2 (step ST1).
5).

The same applies to the correction of the angle conversion constant K2 in the CCW direction, and FIG. 10 is a flowchart showing the correction processing in this case.

[0067]

According to the first aspect of the invention, when the positioning state by the GPS is good and the traveling speed of the moving body is higher than a predetermined speed, the data by the angular velocity sensor and the distance sensor are used. From the GPS to the data by the GPS, and the angular velocity and traveling speed estimated based on the outputs of the angular velocity sensor and the distance sensor are GP.
The correction is performed for each data that satisfies the predetermined condition received from S, and the latest correction value is stored. On the other hand, when the positioning state by the GPS becomes poor, or when the traveling speed becomes lower than a predetermined traveling speed, the data by the GPS is switched to the data by the angular velocity sensor and the distance sensor. Along with this, data switching means for correcting the data by the angular velocity sensor and the distance sensor with the latest correction value stored to estimate the current position, the current traveling direction, and the traveling speed. Since it is configured like this, even if you are driving in a tunnel where reception is not possible or under poor reception conditions under a high-rise building,
Even if the traveling speed is low, there is an effect that the current position, the current traveling direction, the current traveling speed, etc. can be accurately estimated based on the angle information and the traveling speed information.

According to the second aspect of the invention, the latest position data and the latest azimuth data which continuously satisfy the predetermined conditions are set as the reference of the position and the traveling direction when the positioning by GPS is good. It will be updated sequentially and GP
When the positioning state due to S becomes poor, the updated reference value, the output of the distance sensor and the output of the angular velocity sensor are used to infer data such as a position such as latitude and longitude, a traveling direction and speed. Since it is configured so as to obtain, there is an effect that the present position, the present traveling direction, the present traveling speed, etc. can be accurately estimated and obtained.

According to the third aspect of the present invention, the distance conversion constant used for estimating the current position, traveling direction, speed, etc. when the GPS positioning state is poor is used when the GPS positioning state is good. Since it is configured to calculate from the GPS speed data and the pulse indicating the traveling distance, the current position, the current traveling direction, the current traveling speed, etc. when the positioning state by the GPS becomes poor are accurately estimated and obtained. There is an effect that can be.

According to the fourth aspect of the invention, the average value of the change angle data output by the vibration gyro within a predetermined number of fixed ranges is obtained as the offset amount of the vibration gyro, and the obtained offset amount is sequentially updated. Since it is configured to correct the drift of the offset amount, the error contained in the output of the vibration gyro is suppressed, and when the GPS data becomes unusable, the current position, the current traveling direction, the current traveling speed, etc. Has the effect of accurately estimating and obtaining.

According to the fifth aspect of the invention, the sensitivity characteristic of the vibration gyro is corrected according to the difference between the azimuth change obtained by the GPS and the angle change obtained by the vibration gyro when the vehicle turns during traveling. With this configuration, it is possible to accurately estimate and obtain the current position, the current traveling direction, the current traveling speed, and the like when the GPS data becomes unusable.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing an estimation unit in the navigation device according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing a data switching process in the navigation device according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a navigation device according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing a navigation device according to a third embodiment of the present invention.

FIG. 6 is a table showing distances per minute of longitude in the navigation device according to the third embodiment of the present invention.

FIG. 7 is a block diagram showing a navigation device according to a fourth embodiment of the present invention.

FIG. 8 is a block diagram showing a navigation device according to a fifth embodiment of the present invention.

FIG. 9 is a flowchart showing a correction process of an angle conversion constant K1 in the CW direction in the navigation device according to the fifth embodiment of the present invention.

FIG. 10 is a flowchart showing a correction process of a CCW direction angle conversion constant K2 in a navigation device according to a fifth embodiment of the present invention.

FIG. 11 is a block diagram showing a conventional navigation device.

FIG. 12 is a conceptual diagram showing a configuration of a vibrating gyro.

[Explanation of symbols]

 23 distance sensor 24 vibration gyro 25 estimation unit (estimation means) 26 data switching means 30 reference value setting means 31 updating means 32 distance conversion constant calculation means 33 distance conversion constant correction means 34 offset / drift correction means 35 sensitivity characteristic correction means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Kawamoto 2-17-1, Nakakazezumi, Komae City, Tokyo 102 Paseo 102 (72) Inventor Mitsuhiro Sasaki 1-37, Kamisoshiya, Setagaya-ku, Tokyo 5 Sani House No. 5

Claims (5)

[Claims] 1. A current position of a mobile unit, which receives data from a global positioning satellite system (hereinafter referred to as GPS),
The current direction of travel, running speed, etc. are measured based on the received data, and when GPS data cannot be received, the current speed is detected based on the angle information detected by the angular velocity sensor and the running speed information detected by the distance sensor. position,
In a navigation device that estimates the current traveling direction and traveling speed, when the positioning state by the GPS is good and the traveling speed is equal to or higher than a predetermined speed, the GPS is determined from the data by the angular velocity sensor and the distance sensor. When the positioning state by the GPS becomes poor, or when the traveling speed becomes less than a predetermined speed, the data by the GPS is switched to the data by the angular velocity sensor and the distance sensor. And a predetermined condition that the angle and the traveling speed based on the outputs of the angular velocity sensor and the distance sensor are received from the GPS when the positioning state by the GPS is good and the traveling speed is equal to or higher than a predetermined speed. Is corrected for each data that satisfies And a means for estimating the current position, the current traveling direction, and the traveling speed by correcting the data obtained by the angular velocity sensor and the distance sensor with the latest correction value. Navigation device. 2. When the positioning by GPS is poor, the data by GPS is switched to the angle information detected by the angular velocity sensor and the traveling speed information detected by the distance sensor, and the current position, the current traveling direction, and the traveling speed. And a reference value setting means for setting the latest position data and the latest azimuth data, which continuously satisfy a predetermined condition, to the reference values of the position and the traveling direction when the positioning state by GPS is good. Updating means for sequentially updating the reference value set by the reference value setting means based on the GPS data; and when the positioning state by the GPS is poor, the reference value updated by the updating means and the output of the distance sensor. And an estimator that estimates and obtains the current position, current traveling direction, and traveling speed based on the output of the angular velocity sensor. A navigation device comprising steps. 3. When the positioning by GPS is poor, the GPS data is switched to the angle information detected by the angular velocity sensor and the traveling speed information detected by the distance sensor, and the current position, the current traveling direction, and the traveling speed are set. And a reference value setting means for setting the latest position data and the latest azimuth data, which continuously satisfy a predetermined condition, as the reference values of the position and the traveling direction when the positioning state by GPS is good. The reference value set by the reference value setting means is the GPS
Update means for sequentially updating the current position based on the data by the above, and when the positioning state by GPS is poor, the current position is determined based on the reference value updated by the update means, the output of the distance sensor and the output of the angular velocity sensor. Predicting means for estimating and finding data such as the current traveling direction and traveling speed, and a distance conversion constant that defines the distance per pulse of the pulse output from the distance sensor used in the estimating means are determined by the GPS positioning state. When the GP is good,
The distance conversion constant calculation means obtained by calculation from the pulse output according to the speed data and the traveling distance by S, and the distance conversion constant obtained by calculation by the distance conversion constant calculation means A navigation device, comprising: a distance conversion constant correcting unit that corrects by averaging. 4. When the positioning by GPS is poor, the GPS data is switched to the angle information detected by the vibration gyro and the traveling speed information detected by the distance sensor, and the current position, the current traveling direction, and the traveling speed are set. And a reference value setting means for setting the latest position data and the latest azimuth data, which continuously satisfy a predetermined condition, as the reference values of the position and the traveling direction when the positioning state by GPS is good. The reference value set by the reference value setting means is the GPS
Updating means for sequentially updating the data based on the data of 1., and when the positioning state by GPS is poor, based on the reference value updated by the updating means, the output of the distance sensor and the output of the vibration gyro, the current position, The estimating means for estimating the current traveling direction, traveling speed, etc., and the distance conversion constant used by the estimating means and defining the distance per pulse of the pulse output according to the traveling distance, are determined by the GPS. When the condition is good, the distance conversion constant calculation means obtained by calculation from the pulse output according to the speed data by the GPS and the traveling distance, and the distance conversion constant obtained by calculation by the distance conversion constant calculation means, Distance conversion constant correcting means for correcting by averaging the two old and new distance conversion constants, and the vibration when the traveling speed is zero. Assuming that the variation angle data output by the gyro is within a certain range, the average value of a predetermined number of variation angle data output by the vibration gyro is calculated as the offset amount of the vibration gyro, and is updated sequentially. Thus, the navigation device is provided with an offset / drift correction means for correcting the drift of the offset amount. 5. When the positioning state by GPS is poor,
In a navigation device that switches data from GPS to angle information detected by a vibration gyro and traveling speed information detected by a distance sensor and estimates the current position, traveling direction, and traveling speed, when the positioning state by GPS is good, The reference value setting means for setting the latest position data and the latest azimuth data that continuously satisfy a predetermined condition as reference values for the position and the traveling direction, and the reference value set by the reference value setting means for the GPS
Update means for sequentially updating the current position based on the data of the current position and the current position based on the reference value updated by the updating means, the output of the distance sensor and the output of the vibration gyro when the positioning state by GPS is poor. Of the present traveling direction, traveling speed, etc., and the distance conversion constant used in the estimating means and defining the distance per pulse of the pulse output according to the traveling distance, by the GPS. The distance conversion constant calculation means obtained by calculation from the pulse output according to the speed data by GPS and the traveling distance when the positioning state is good, and the distance conversion constant obtained by calculation by the distance conversion constant calculation means , A distance conversion constant correcting means for correcting by averaging the two old and new distance conversion constants, and when the traveling speed is zero Assuming that the variation of the change angle data output by the vibration gyro is within a certain range, the average value of a predetermined number of change angle data output by the vibration gyro is obtained as the offset amount of the vibration gyro, and is further sequentially calculated. Based on the offset / drift correction means for correcting the drift of the offset amount by updating, the angle change amount obtained by the GPS when turning during traveling, and the angle change amount obtained by the vibration gyro, A navigation device comprising: a sensitivity characteristic correction unit that corrects the sensitivity characteristic of the vibration gyro.