JP3076088B2 - Automatic correction device for distance correction coefficient - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic correction device for a distance correction coefficient, and more particularly to an automatic correction device for a distance correction coefficient which can be used for a navigation device, an engine control device, a speed display device, a mileage display device, and the like. .

[0002]

2. Description of the Related Art Conventionally, there is a so-called self-contained navigation device as a positioning device for various moving objects such as an automobile, an aircraft, and a ship. This self-contained navigation device obtains a two-dimensional displacement (vector quantity) of a moving object from direction data from a direction sensor and speed data from a speed sensor, and integrates the two-dimensional displacement with a reference point to obtain a current position. It was what I wanted. That is, in the case of an automobile, for example, the number of pulses generated during one rotation of the drive shaft is preset, and the distance calculated from the total number of pulses generated from the reference point to the current position is multiplied by a distance correction coefficient. The mileage was required.

As a positioning device using artificial hygiene, a GPS (Global Positioning Sy) is used.
Stem type navigation devices have been developed. This GPS navigation device usually has three or more GPs.
It is configured to receive a radio wave from the S satellite and measure the position of the receiving point from pseudorange data including the time offset of the receiver between each GPS satellite and the receiving point, and the position data of each GPS satellite. .

[0004]

However, in a self-contained navigation device, the detection error of each sensor is accumulated as it is. Becomes large. In a car or the like, a traveling distance error also occurs due to changes in the number of occupants and road conditions. For this reason, there is a problem that the user needs to manually correct the distance correction coefficient by judging that the self-supporting navigation device is overrunning or underrunning when turning around an intersection or the like. In the GPS type navigation device, there is no problem of the accumulated error in the self-contained navigation device, but the change rate (speed) of the pseudorange data due to the Doppler effect of the radio wave from the GPS satellite.
Since the azimuth is obtained by measuring the azimuth, the accuracy of the azimuth data is reduced when the moving speed of the receiving point is low. Furthermore, when the receiving point is stopped, there is a problem that the speed data becomes larger than the actual speed due to the multipath of the radio wave, indicating incorrect azimuth data.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and enables a distance correction coefficient to be automatically corrected to always obtain a correct moving distance of a receiving point, and to provide a user with a correct distance. It is an object of the present invention to provide a distance correction coefficient automatic correction device capable of reducing a burden.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a GPS positioning means for measuring a current position using data from a GPS satellite and a distance are obtained. A speed sensor for outputting speed for
And a data processing means for correcting the distance correction coefficient of the velocity sensor based on the distance between two points obtained from said GPS positioning means, said data processing means, said GPS positioning hand
When the speed data obtained from the step is equal to or more than a predetermined value, the distance correction coefficient is corrected. Also, billing
The invention described in Item 2 is a GPS positioning unit that measures the current position using data from a GPS satellite, a speed sensor that outputs a speed for obtaining a distance, and two points obtained from the GPS positioning unit. Data processing means for correcting a distance correction coefficient of the speed sensor based on the distance between the speed sensor and the speed data from the speed sensor. When the distance is within a predetermined value, the distance correction coefficient is corrected. According to a third aspect of the present invention, there is provided a GPS positioning means for positioning a current position using data from a GPS satellite, a speed sensor for outputting a speed for obtaining a distance,
Data processing means for correcting the distance correction coefficient of the speed sensor based on the distance between two points obtained from the GPS positioning means, wherein the data processing means has a PDOP value equal to or less than a predetermined value, The data is greater than or equal to a predetermined value,
When the difference between the speed data from the PS positioning means and the speed data from the speed sensor is within a predetermined value, the distance correction coefficient is corrected.

[0007]

When the data from the GPS positioning means satisfies a predetermined condition, the distance correction coefficient is corrected by the data processing means based on the distance between the two points obtained from the GPS positioning means. As a result, the distance correction coefficient is automatically corrected, and the occurrence of the error of the moving distance of the receiving point due to the accumulation of the detection error of the speed sensor is prevented.
It is possible to appropriately cope with a case where the distance correction coefficient needs to be corrected due to changes in the number of occupants or road conditions, and to reduce the burden on the user.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of a navigation device using the automatic distance correction coefficient correction device of the present invention. In FIG. 1, the navigation device is a GPS
GPS antenna 3 for receiving radio waves from satellites, this GP
A GPS receiver 4 connected to the output side of the S antenna 3, a GPS-type position calculating means 5 for recognizing a current position of a receiving point (a moving body such as a car) based on a signal from the GPS receiver 4; GPS positioning means 1 composed of:
Self-contained position calculating means 8 for recognizing the current position of a receiving point from a running history based on signals from a direction sensor 6 for detecting a direction and a speed sensor 7 for detecting the speed of a receiving point. And a data processing means 9 connected to the GPS type position calculating means 5, the speed sensor 7 and the self-contained type position calculating means 8 for performing various data processing. Further, a storage device 10 such as a compact disk or a ROM storing map information and the like is connected to the data processing means 9 via a decoder 11, and a display device 12 such as a CRT is connected to the data processing means 9.

The GPS type position calculating means 5, the self-contained type position calculating means 8 and the data processing means 9 are composed of a calculating circuit, a RAM connected to the calculating circuit, and an R for holding a program of each means.
It consists of a microcomputer with OM. The GPS-type position calculating means 5 calculates the current position, speed, etc. of the receiving point based on the signal from the GPS receiver 4 and outputs data to the data processing means 9. Based on the signal from the speed sensor 7 and the current position and speed of the receiving point, the data is output to the data processing means 9. Then, the data processing means 9 corrects the distance correction coefficient for the speed sensor 7 to the self-contained position calculating means 8 when the data from the GPS positioning means 1 satisfies a predetermined condition. Further, the data processing means 9 performs map matching based on data from the GPS type position calculating means 5 or data from the self-contained type position calculating means 8 and map information around the current position drawn from the storage device 10. Then, the current position of the reception point is displayed on the display device 12. Note that the GPS-type position calculation means 5, the self-contained position calculation means 8, and the data processing means 9 may be configured using dedicated calculators.

Here, the distance correction coefficient will be described.
Normally, in an automobile, the speed sensor 7 is installed in the middle of a speedometer cable that rotates in accordance with the rotation of the drive shaft, and a pulse signal is output from the speed sensor 7 with the rotation of the drive shaft. Then, p = 0 when the pulse is output twice each time the drive shaft makes one rotation, p = 1 when the pulse is output four times every time the drive shaft makes one rotation, and the drive shaft makes one rotation. P = 2 when the pulse is output 8 times every time
Assuming that the total number of pulses generated while the car travels between certain points AB is n and the distance correction coefficient is k, AB
The distance d between them is represented by the following equation (1).

[0011]

(Equation 1) Note that, in the above equation (1), l = 0.39.
[M]. This l is p = 1 (drive shaft is 1
This is a numerical value specified in JIS based on the case where the number of pulses generated each time the motor rotates is 4). The distance correction coefficient k is expressed by the following equation (2) from the above equation (1).

[0012]

(Equation 2) Conventionally, the distance correction coefficient k is set to be closest to 1 in relation to the value of p, and thereafter, the distance correction coefficient k is used without correction. For this reason, the detection errors of the sensors are accumulated as they are, and the traveling distance error increases.

On the other hand, according to the present invention, when the data from the GPS positioning means 1 satisfies a predetermined condition, the distance correction coefficient k is corrected based on the distance between two points AB obtained from the GPS positioning means 1. You. That is, when the navigation device is in the initial state, the value of the distance correction coefficient k is the largest.
Is determined by the data processing means 9. Thereafter, every time the distance between the two points is obtained from the GPS positioning means 1, the distance data is substituted into the equation (2) to obtain the distance correction coefficient k, and the distance correction coefficient k thus obtained is obtained.
To converge. More specifically, as shown in the following equation (3), the previous distance correction coefficient obtained by substituting the initially set distance correction coefficient k and the distance data from the GPS positioning means 1 into the equation (2) a certain percentage of the difference between the coefficient k _n-1, the current distance correction coefficient k _n in addition to the previous distance correction coefficient k _n-1.

[0014]

(Equation 3) As described above, by automatically correcting the distance correction coefficient k based on the distance data from the GPS positioning means 1, it is possible to prevent the occurrence of an error in the moving distance of the receiving point due to the accumulation of the detection error of the speed sensor, It is possible to appropriately cope with a case where the distance correction coefficient needs to be corrected due to a change in the number or road state, and to reduce the burden on the user.

Next, based on the distance between the two points obtained from the GPS positioning means 1, the data processing means 9 calculates the distance correction coefficient k
The predetermined condition of the data from the GPS positioning means 1 required to correct the error will be described.

In the present invention, when the data processing unit 9 confirms that the data from the GPS positioning unit 1 satisfies the following three conditions, the above-described correction of the distance correction coefficient k is performed.

The PDOP value is equal to or less than a predetermined value. Speed data from the GPS positioning means 1 is equal to or greater than a predetermined value. Speed data from GPS positioning means 1 and speed sensor 7
The difference from the speed data from is within a predetermined value.

The above PDOP (Position Di)
The “lution Precision” value is an index of how the error of the GPS satellite position is reflected on the position of the reception point in the GPS positioning. The larger the value, the larger the error of the positioning. Therefore, in the present invention, PDOP
A condition that the value is equal to or less than a predetermined value is one condition for adopting the data from the GPS positioning means 1, and 4 is preferably empirically set as the PDOP value. That is, under the arrangement situation of the GPS satellites whose PDOP value is 4, if the average error of the distance measurement to the GPS satellites is 10 m, the standard of the positioning error is 40 m as shown below. ,
High-precision positioning becomes possible.

Estimation of positioning error = PDOP value × average error of distance measurement = 4 × 10 m = 40 m
That the speed data from was greater than or equal to the predetermined value
In GPS positioning, since the azimuth is obtained by measuring the rate of change (speed) of pseudorange data due to the Doppler effect of radio waves from GPS satellites, the accuracy of the azimuth data decreases when the moving speed of the receiving point is low. This is to prevent this. The minimum speed at which the accuracy of the azimuth data can be kept high is preferably about 30 km / h.

Further, by assuming that the difference between the speed data from the GPS positioning means 1 and the speed data from the speed sensor 7 is within a predetermined value, it is possible to eliminate an azimuth data error due to multipath of radio waves. The predetermined value is 3
It is preferably about km / h.

In the present invention, the data processing means 9 corrects the distance correction coefficient k when five conditions, which are the above three conditions plus the following two conditions, are satisfied. You may.

The data from the GPS positioning means 1 is obtained three times consecutively at an interval within a predetermined time. The azimuth data from the GPS positioning means 1 for three consecutive times is within a predetermined value.

The above-mentioned predetermined time is preferably about 2 seconds, and is preferably three times consecutively within two seconds.
The condition that data from the GPS is stably received for the past several seconds from the present time is maintained by requiring that data from the GPS is obtained.

The predetermined value is preferably about ± 10 °, and when the azimuth data is within ± 10 ° three times in a row, the receiving point is in a straight traveling state. GPS azimuth can be obtained.

Here, the GPS positioning means 1 will be described. FIG. 2 is a block diagram showing the GPS positioning means 1,
GPS antenna 3 has preamplifier 31 and bandpass filter 3
2, a crystal oscillator 35 for outputting a reference frequency signal, which is an overall timing control signal, and a clock signal for controlling the operation timing of the signal processing means 37 based on the reference frequency signal Is provided with a clock oscillation circuit 36 that forms
The mold position calculating means 5 is connected to the signal processing means 37.

The GPS receiver 4 receives a signal carrier of a GPS satellite based on a reference frequency signal oscillated by a crystal oscillator 35,
A frequency synthesizing circuit 41 for generating a signal having the same pattern as data relating to the position of the GPS satellite and the state of the clock in the GPS satellite, and a clock signal output from the clock oscillation circuit 36 and having a code signal having the same pattern as the ranging signal , And the output signals of the frequency synthesis circuit 41 and the code generation circuit 42
A data and carrier detector 43 for correlation detection of data and a carrier wave of orbits of a clock and a GPS satellite in a PS satellite, and a code signal output from the code generation circuit 42 for correlation detection of the distance measurement signal. And a code lock detector 44.

The azimuth sensor 6 constituting the self-contained positioning means 2 is a known geomagnetic sensor or a gyro compass, and detects the moving direction of the receiving point. A known rotation speed sensor or the like is used as the speed sensor 7 for detecting the speed of the receiving point. Is done. Then, by accumulating the moving distance in accordance with the change in the moving direction of the receiving point detected by the direction sensor 6, the moving history of the receiving point can be obtained. As a result, the movement path from the reference point is calculated, and the current position is measured.

Next, the operation of the embodiment shown in FIG. 1 will be described with reference to FIG. First, the navigation device is activated, the radio wave from the GPS satellite is received by the GPS antenna 3, and the data from the GPS positioning means 1 satisfies the above-mentioned condition (1) or satisfies the condition (1). It is determined by the data processing means 9 whether or not to perform (S1). Then, when the determination is Yes, it is determined whether or not it is in the initial state (S2),
In the initial state, p is 0, 1,
The value p is determined such that the distance correction coefficient k becomes closest to 1 by changing to 2 (S3). If it is determined in (S2) that the state is not the initial state, the step of (S3) is omitted. Next, an operation based on Equation 2 (S4),
Then, the calculation (S5) based on Expression 3 is performed to correct the distance correction coefficient k. If the determination in (S1) is No, the process ends without performing the automatic correction of the distance correction coefficient k.

Each time data is obtained from the GPS positioning means, the operation according to the above flow chart is performed.
Automatic correction of the distance correction coefficient k is performed each time the data from the S positioning means satisfies a predetermined condition.

In the above embodiment, the automatic distance correction coefficient correction device of the present invention is used for a navigation device. However, the present invention is not limited to this.
It can be used for an engine control device, a speed display device, a traveling distance display device, and the like.

[0031]

As described above in detail, according to the present invention, when the data from the GPS positioning means satisfies a predetermined condition, the distance correction based on the distance between two points obtained from the GPS positioning means. The coefficient is automatically corrected by the data processing means, thereby preventing the occurrence of an error in the moving distance of the receiving point due to the accumulation of the detection error of the speed sensor, and correcting the distance correction coefficient due to the number of occupants and changes in road conditions. It is possible to appropriately cope with a necessary case and reduce the burden on the user.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of an automatic distance correction coefficient correction apparatus according to the present invention.

FIG. 2 is a block diagram showing GPS positioning means in the present invention.

FIG. 3 is a flowchart for one embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 GPS positioning means 2 Self-contained positioning means 3 GPS antenna 4 GPS receiver 5 GPS position calculating means 6 Direction sensor 7 Speed sensor 8 Self-supporting position calculating means 9 Data processing means 10 Storage Device 11 ... Decoder 12 ... Display device

Claims (3)

(57) [Claims] 1. GPS positioning means for positioning a current position using data from a GPS satellite; a speed sensor for outputting a speed for obtaining a distance; and a distance between two points obtained from the GPS positioning means. Data processing means for correcting the distance correction coefficient of the speed sensor on the basis of: the data processing means, when the speed data obtained from the GPS positioning means is greater than or equal to a predetermined value, An automatic correction device for a distance correction coefficient, which corrects a correction coefficient. 2. A GPS positioning means for positioning a current position using data from a GPS satellite, a speed sensor for outputting a speed for obtaining a distance, and a distance between two points obtained from the GPS positioning means. Data processing means for correcting the distance correction coefficient of the speed sensor on the basis of a difference between the speed data from the GPS positioning means and the speed data from the speed sensor within a predetermined value. Wherein the distance correction coefficient is corrected. 3. A GPS positioning means for positioning a current position using data from a GPS satellite; a speed sensor for outputting a speed for obtaining a distance; and a distance between two points obtained from the GPS positioning means. Data processing means for correcting the distance correction coefficient of the speed sensor based on the data processing means, wherein the data processing means has a PDOP value equal to or less than a predetermined value,
A distance correction coefficient for correcting the distance correction coefficient when a difference between the speed data from the GPS positioning means and the speed data from the speed sensor is within a predetermined value; Automatic correction device.