JP2001093100A - Device and method for displaying spatial position - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make visually confirmable the three-dimensional estimation error including latitude, longitude, and altitude at the time of obtaining the spatial position of a flying object. SOLUTION: A spatial position detecting part 11 such as a GPS receiver or an ISN and an altimeter detects the position of a flying object in three- dimension (latitude, longitude, and altitude). A calculating part 12 estimates an error in the detected position according to the error characteristics of equipment used as the spatial position detector. A display part 13 three-dimensionally displays the position of the flying object and the error range based on the position data indicating the position of the flying object and the estimated error data. Thus, it is possible to confirm the estimated position of the flying object including the latitude, longitude, and altitude from the three-dimensional display.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spatial position display device for displaying the spatial position of a flying object such as an aircraft, and more particularly to a spatial position capable of visually displaying three-dimensional positional errors of latitude, longitude and altitude. The present invention relates to a display device and a spatial position display method.

[0002]

2. Description of the Related Art With the development of navigation devices, the navigation accuracy of flying objects such as aircraft has been dramatically improved, and accordingly, there has been a demand for denser navigation (with a smaller margin) than ever before. Came. What is important in this case is to grasp the uncertainty of the spatial position of each flying object, that is, the navigation error.

Here, as a method of displaying the position of the flying object, as for a plane position (latitude and longitude), an error circle centered on the estimated position of the flying object is displayed, and the positional error is displayed in a planar manner. However, as for the altitude, a method of digitizing and displaying the altitude error is generally used.

[0004]

As described above, in the conventional flat display method, the position of the flying object can be confirmed only in a planar manner. For this reason, when the positions of the flying objects seem to overlap on the screen, it is not possible to immediately determine whether or not the altitude of each flying object is the same, and there has been a problem that the flying object is extremely defective. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and can obtain a three-dimensional estimation error including altitude as well as latitude and longitude when obtaining a spatial position of a flying object. It is an object to provide a spatial position display device and a spatial position display method.

[0006]

A spatial position display apparatus according to the present invention comprises: a position detecting means for detecting the position of a flying object in three dimensions; and an error estimating means for estimating an error range of the position detected by the position detecting means. Means, and display means for three-dimensionally displaying the position of the flying object and its error range based on the position data output from the position detecting means and the estimated error data output from the error estimating means. Is done.

In such a configuration, for example, a GPS receiver or an INS and an altimeter are used as the position detecting means, and the position of the flying object is detected in three dimensions (latitude, longitude, altitude). The error estimating means estimates an error with respect to the detected position in accordance with an error characteristic of a device used as the position detecting means. The display means,
The position of the flying object and its error range are three-dimensionally displayed based on the position data indicating the position of the flying object and the estimated error data.

More specifically, GP as the position detecting means
When the S receiver is used, a circle whose radius is equivalent to the horizontal estimation error is drawn on the horizontal plane based on the position data output from the GPS receiver and the estimation error data output from the error estimating means. A sphere centered on the position of the flying object and having an ellipse whose minor axis corresponds to the horizontal estimation error and whose major axis corresponds to the vertical estimation error is displayed. When an inertial navigation device and an altimeter are used as the position detecting means, the position data output from the inertial navigation device and the altitude data output from the altimeter and the estimated error data output from the error estimating means are used. Based on the above, a circle centered on the position of the flying object is displayed by combining a circle depending on the operation time indicating the plane error and a line segment depending on the altitude indicating the altitude error. With such a three-dimensional display, the estimated position of the flying object including the altitude as well as the latitude and longitude can be confirmed.

Further, the present invention has mode switching means for instructing switching of the display mode, and displays the position of the flying object and its error range in a display format according to the display mode designated by the mode switching means. It is characterized by doing.

By providing such mode switching means, the estimated position of the flying object can be confirmed in any display mode. As the display mode, in addition to the bird's-eye display mode for three-dimensionally displaying the flying object position and its error range as described above, a flat display mode for displaying a plane except for altitude,
There is an altitude display that displays only altitude.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a spatial position display device according to one embodiment of the present invention. This spatial position display device displays the spatial position (three-dimensional coordinate position) of a flying object such as an aircraft, including an estimation error.
As shown in (1), it comprises a spatial position detecting unit 11, a calculating unit 12, a display unit 13, and a mode switching unit 14.

The spatial position detector 11 detects the position of the flying object by three.
Dimensions are detected, and the position data is output to the calculation unit 12. In this case, the plane position (latitude, longitude) is G
PS (Global Positioning System), INS (inertial navigation system), VOR (VHF omni-directional range), DME (distance measuring equ)
ipment: distance measuring device), and the altitude is specified using a GPS, a barometric altimeter, a radio altimeter, or the like.

A plurality of GPS (at least four or more)
, The three-dimensional position of the receiving point, that is, the latitude, longitude, and altitude can be detected. INS uses gyro and acceleration type,
The position is detected by detecting an acceleration vector applied to the aircraft. However, since only information of latitude and longitude can be obtained from INS, an altimeter is required for altitude. The same applies to VOR and DME. Since only information of latitude and longitude can be obtained, an altimeter is required for altitude.

As the altimeter, a radio altimeter or a barometric altimeter is used. The radio altimeter receives reflected waves of radio waves emitted from a flying object to the ground, and detects altitude by measuring the round trip time of the radio waves. The barometric altimeter measures the barometric pressure at the flight altitude and detects the altitude from the sea surface based on a standard barometric-altitude relationship.

The calculating unit 12 performs an error estimating process for estimating the error of the three-dimensional position coordinates (latitude, longitude, altitude) of the flying object obtained by the spatial position detecting unit 11, and the result is obtained. The estimated error data is output to the display unit 13 together with the position data. The display unit 13 three-dimensionally displays the position of the flying object and its error range in a predetermined format based on the estimated error data obtained by the calculation unit 12 and the position data. The mode switching unit 14 is an operation unit for instructing the display unit 13 to switch the display mode.

FIG. 2 is a view showing a display example of a spatial position.

When the GPS is used as the spatial position detecting unit 11, the position of the flying object and its error range are represented by a sphere 22 centered on the own aircraft position 21, as shown in FIG. You. The range indicated by the sphere 22 is a latitude, longitude, and altitude error range. Note that, more strictly, the horizontal plane and the vertical plane may not be the same due to the accuracy of the altitude error, and are represented by an ellipsoidal sphere 22 'as shown in FIG. 2B.

When the INS and the altimeter are used, as shown in FIG. 2C, the space of the flying object and its error range are represented by a cylinder 24 having its own position 23 as its center. The range indicated by the cylinder 24 is the latitude, longitude, and altitude error ranges.

FIG. 3 is a diagram showing switching of the display mode.

In this embodiment, three modes 1 to 3 of "bird's-eye display", "plane display", and "altitude display" are provided as modes for displaying the spatial position of the flying object, and these are arbitrarily selected. You can switch to In the “bird's eye display” mode 1, the coordinates of the latitude, longitude, and altitude of the flying object and their error ranges are represented (FIG. 2). In the “planar display” mode 2, the coordinates of the latitude and longitude of the flying object and their error ranges are expressed. In the “altitude display” mode 3, the coordinate position of the altitude of the flying object and its error range are expressed. These modes 1
The switching of No. 3 is performed through the mode switching unit 14.

The operation of the spatial position display processing of the present apparatus will be described below.

FIG. 4 is a flowchart showing the operation of the spatial position display processing in this embodiment.

First, the position of the flying object is detected three-dimensionally by the spatial position detecting section 11 and position data POS (Lat, Lon, Alt) indicating latitude, longitude and altitude are calculated by the calculating section 12.
(Step A11). In addition, POS (La
t) is latitude, POS (Lon) is longitude, and POS (Al
t) indicates the altitude. The detection of the spatial position here is defined as GP
The so-called navigation calculation using VOR, DME, etc. in addition to S and INS is performed. In this case, the GPS can obtain the latitude, longitude, and altitude positions at the same time.
Since VOR and DME can only obtain the position of latitude and longitude, it is necessary to use an altimeter such as a position radio altimeter or a barometric altimeter for altitude.

In the calculation unit 12, the spatial position detection unit 11
Through the three-dimensional position data POS (Lat, Lon,
Once Alt) is obtained, processing for estimating these errors is performed (step A12). Specifically, the spatial position detector 11
The error is estimated as follows in accordance with the error characteristics of the device used as.

(A) GPS In many GPS receivers, a generally output FOM value is used. The FOM value is a value indicating the rank of the estimation error. For example, if the FOM value is “1”, the spatial position error is 25 m (SEP), and the FOM value is
If the value is “2”, the spatial position error is 50 m (SEP)
Becomes

In a more precise expression, EHPE (estimated horizon position) indicating an estimation error in the horizontal direction is used.
error) value and EVPE (es) indicating the estimation error in the vertical direction.
timated vertical position error) value. Both the EHPE value and the EVPE value are obtained from the GPS receiver.
The EVPE value is used as the altitude estimation error.

(B) INS In INS, a plane error of the flying object is obtained. This plane error increases in proportion to time. For example, 0.5 nm / h
In the case of an INS having a specification of (CEP), that is, in the case of an INS having a plane error of 0.5 nm per hour,
The plane error is 0.5 × t (CE
P). Note that nm is a unit representing length, and is called "nautical miles" or "nautical mile", and 1 (nm) is 1852 m. This plane error is used as an estimation error of latitude and longitude. However, INS
In this case, since information on altitude cannot be obtained, it is necessary to estimate an altitude error when an altimeter is used, as described below.

(C) VOR In VOR, a plane error of the flying object is obtained. This plane error increases in proportion to the distance from the VOR ground station. For example, in the case of a general azimuth error (θ) of 4.5 ° (2σ),
Assuming that the distance from the VOR station is x, the plane error can be easily estimated as x · tan (θ / 2) = 0.039x (2σ). This plane error is used as an estimation error of latitude and longitude. However, in VOR, the above IN
Since information on altitude cannot be obtained similarly to S, it is necessary to estimate an altitude error when an altimeter is used as described below.

(D) DME In DME, a plane error of the flying object is obtained. This plane error increases in proportion to the distance from the DME ground station. For example, in the case of a general error “0.5 nm is larger (2σ) of 3% of the distance from the DME station”, the DM
If the distance (x) from the E station is 16.6 nm or less, the plane error can be estimated to be 0.5 nm (2σ). If the distance (x) from the DME station is 16.7 nm or more, the plane error is It can be estimated as 0.03x nm (2σ). This plane error is used as an estimation error of latitude and longitude.
However, in the DME, information on altitude cannot be obtained as in the case of the INS. Therefore, it is necessary to estimate an altitude error when an altimeter is used as described below.

(E) Altimeter When using a barometric altimeter or a radio altimeter as an altitude source, these altimeters increase in error as the altitude rises. can get.

That is, when a barometric altimeter is used,
Generally, the error increases as the altitude increases. For example, a common error "error 15 ft at sea level,
When the altitude is h and the error is 80 ft at 50,000 ft above sea level, the numerical value is expressed as 0.013h + 15 ft (2σ value).

When a radio altimeter is used, the error generally increases as the altitude increases. For example, a general error “error 2 ft at 100 ft above ground,
When the altitude is 100 to 5000 ft and the error is 2% ", and the altitude is h, the h is 0 to 100 ft: 2 ft and the h is 100 to 5000 ft: 0.02 ft. ).

It is also possible to use GPS as an altitude source. In this case, the altitude error is calculated using the above-mentioned EV.
This is a value corresponding to the PE value.

Numerical values representing error amounts obtained by the characteristics of each device are, for example, 95% value, 1σ value, 2σ value,
It is assumed that unit conversion is performed in accordance with a unified standard such as a CEP value and a SEP value.

When the error with respect to the spatial coordinates is estimated in this way, the calculation unit 12 calculates the position data POS of the flying object.
(Lat, Lon, Alt) and its estimated error data Er
By giving r (Rad, Alt) to the display unit 13, the position of the flying object and its error range are three-dimensionally displayed on the screen of the display unit 13 (step A13). Err (Rad) indicates an error in the radial direction (latitude and longitude), and Err (Alt) indicates an error in altitude.

In this case, the solid representing the error range of the spatial position is determined according to the performance of each error. For example, using GPS or INS as an example, the error range of the spatial position is expressed as follows.

(A) GPS According to the definition of the FOM value of the GPS receiver, the error range is represented by a sphere 22 centered on the own position 21 as shown in FIG. For example, if the FOM value is “1”, the radius 25
m (SEP) can be represented by a sphere 22.

More strictly, the EHPE value and the EVPE value are used as the estimation error Err (Rad), and the EVPE value is used as the estimation error Er.
Used as r (Alt). That is, the horizontal plane is a circle whose radius is equivalent to the EHPE value,
By defining the long longitude as an ellipse corresponding to the EVPE value, an elliptical sphere 22 'as shown in FIG. 2B is displayed.
The range indicated by this sphere 22 or ellipsoidal sphere 22 ′ is latitude,
It is the error range of longitude and altitude.

(B) INS A circle that depends on the operation time representing the plane error and a line segment (perpendicular to the ground) that represents the altitude error are combined together as shown in FIG. The error range is represented by a cylinder 24 centered on the position 23.

For example, if the INS has a specification of 0.5 nm / h (CEP), the plane error represented by 0.5 × t (CEP) is used as the estimated error Err (Rad).
Also, an altitude error obtained from an altimeter is used as the estimation error Err (Alt). The range indicated by the cylinder 24 is the latitude, longitude, and altitude error ranges.

As described above, when the GPS receiver is used, a three-dimensional display as shown in FIGS. 2A and 2B is displayed on the screen of the display unit 13. 2
The three-dimensional display as shown in (c) is made on the screen of the display unit 13. In the case where VOR or DME is used, a three-dimensional display as shown in FIG. 2C is displayed on the screen of the display unit 13 in the same manner as in the case of INS. This allows the operator to visually check the estimated position of the flying object including the altitude error.

In this embodiment, three modes 1 to 3 of "bird's-eye display", "plane display", and "altitude display" are provided as modes for displaying the spatial position of the flying object.
As shown in FIG. 3, these modes 1 to 3 can be arbitrarily switched by operating the mode switching unit 14.

Hereinafter, the display mode switching processing will be described.

FIG. 5 is a flowchart showing the operation of the display mode switching process.

For example, the mode switching unit 14 sets the mode 1 to
Assume that the switch 3 is a switch that can be sequentially switched.
When an arbitrary mode is selected by the mode switching unit 14 (step B11), the display unit 13 first determines whether or not the mode 1 is selected (step B12).
When the mode 1 is selected, that is, the mode switching unit 1
4 outputs the mode 1 switching signal (Yes in step B12), the display unit 13 displays the position data POS (Lat,
Lon, Alt) and estimated error data Err (Rad, Alt) indicating an error in the radial direction (latitude, longitude) and an altitude error.
Bird's-eye display is performed using t) (step B13). Here, the bird's-eye display means three-dimensional display in a form including an altitude error as shown in FIG.

If the selected mode is not mode 1, the display unit 13 determines whether mode 2 is selected next (step B14). When mode 2 is selected, that is, when the mode switching unit 14 outputs a mode 2 switching signal (Yes in step B14), the display unit 13 displays position data indicating the latitude and longitude of the flying object. POS (Lat, Lon) and estimated error data Err indicating an error in the radial direction (latitude, longitude)
Perform planar display using (Rad) (Step B1)
4). The plane display is to display a plan view when the three-dimensional solid in FIG. 2 is viewed from above.

If the selected mode is not mode 2, the display unit 13 determines whether mode 3 is selected next (step B16). Mode 3
Is selected, that is, when a mode 3 switching signal is output from the mode switching unit 14 (Yes in step B16), the display unit 13 displays the position data POS (Alt) indicating the altitude of the flying object. And the altitude is displayed using the estimated error data Err (Alt) indicating the altitude error (step B14). The altitude display is to display a side view of the three-dimensional solid in FIG. 2 when viewed from the side.

As described above, the spatial position of the flying object and the error range thereof can be visually confirmed in the three display modes of the bird's-eye display, the plane display, and the altitude display, and the navigation error can be analyzed in more detail.

The above description has been made on the assumption that the mode switching unit 14 is a switch capable of sequentially switching the modes 1 to 3;
When three switches corresponding to .about.3 are provided, it is not necessary to sequentially check which mode is selected as shown in FIG. 5, and the corresponding mode is determined based on a specific mode signal output from each switch. Display according to the mode signal can be performed.

[0051]

As described above in detail, according to the present invention, the position of a flying object is detected three-dimensionally and its error range is estimated, and the position data obtained as the position detection result and the error estimation result are obtained. Since the position of the flying object and its error range are displayed three-dimensionally based on the estimated error data obtained as above, when obtaining the spatial position of the flying object, three-dimensional estimation including altitude along with latitude and longitude is performed. Errors can be visually confirmed, and more accurate and quick navigation can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a spatial position display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a display example of a spatial position by the spatial position display device.

FIG. 3 is a diagram showing switching of a display mode by the spatial position display device.

FIG. 4 is a flowchart showing an operation of a spatial position display process by the spatial position display device.

FIG. 5 is a flowchart showing an operation of a display mode switching process by the spatial position display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Spatial position detection part 12 ... Calculation part 13 ... Display part 14 ... Mode switching part 21 ... Own position 22 ... Sphere 22 '... Elliptical sphere 23 ... Own position 24 ... Cylinder 1 ... Bird's-eye display mode 2 ... Flat display mode 3: Altitude display mode

Claims (5)

[Claims] 1. A position detecting means for detecting a position of a flying object in three dimensions, an error estimating means for estimating an error range of a position detected by the position detecting means, and position data output from the position detecting means. And a display means for three-dimensionally displaying the position of the flying object and its error range based on the estimated error data output from the error estimating means. 2. A mode switching means for instructing a switching of a display mode, wherein the display means displays a position of the flying object and an error range thereof in a display format according to the display mode instructed by the mode switching means. The spatial position display device according to claim 1, wherein the display is performed. 3. A GPS receiver for detecting a position of latitude, longitude and altitude of a flying object, and the GPS receiver based on an error characteristic inherent to the GPS receiver.
Error estimating means for estimating an error in the horizontal direction and vertical direction of the position detected by the S receiver; and a radius having a radius based on the position data output from the GPS receiver and the estimated error data output from the error estimating means. The circle corresponding to the horizontal estimation error is a horizontal plane, the minor axis is the horizontal estimation error, and the major axis has an ellipse corresponding to the vertical estimation error as the vertical plane. And a display means for displaying a sphere. 4. An inertial navigation device for detecting the latitude and longitude positions of the flying object, an altimeter for detecting the altitude of the flying object, and detection by the inertial navigation device based on an error characteristic inherent to the inertial navigation device. Estimate the plane error of the position,
Error estimating means for estimating an error of the altitude detected by the altimeter based on an error characteristic unique to the altimeter; and position data output from the inertial navigation device, altitude data output from the altimeter, and Based on the output estimation error data, a circle centering on the position of the flying object is displayed by combining a circle depending on the operation time indicating the plane error and a line segment depending on the altitude indicating the altitude error. A spatial position display device comprising a display means. 5. A position of the flying object is detected in three dimensions, an error range of the detected position is estimated, and position data obtained as the position detection result and estimation error data obtained as the error estimation result are provided. A three-dimensional display of the position of the flying object and an error range thereof based on the method.