JPH03183908A - Position display device - Google Patents

Abstract

PURPOSE:To measure information on a position display with high accuracy by inputting the distance and azimuth between two points in the position display by using a measurement point input means in consideration of projection and processing the input values by using an arithmetic means. CONSTITUTION:Measurement points for distances and azimuths which are obtained as coordinates on a large-sized display device 1 capable of displaying various positions on a chart are inputted to the large-sized display device 1 by using an evaluation point input means. The measurement point input information is led to a device coordinate reconversion part 3 at the same time and outputted in terms of position information on a projection coordinate system. This position information inputted to various projection reconverting means 4 and converted into latitude and longitude data, which are outputted to a start point reset switch 5 for inputting a distance measurement start point position. The start point and end point of distance measurement from this switch 5 are inputted to a distance/azimuth arithmetic part 6 to calculate the distance and azimuth between two points, which are outputted to a distance and azimuth display part 7. The display part 7, therefore, displays the input information on the distance and azimuth on the large-sized display device 1. Consequently, the distance and azimuth between the two points can be measured and displayed with high accuracy.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a device that is mounted on a ship and can display information including the position of the ship and various positions related to this ship. More specifically, the present invention relates to a position display device that can measure the distance and direction between two indicated points when indicating the position of a ship on a nautical chart.

<Prior art> Conventionally, this type of position display device has a large display, and usually a nautical chart to be used is placed on the display and various information is projected and displayed on the chart. There are known configurations that
(See Japanese Utility Model Publication No. 6440014).

<Problems to be Solved by the Invention> Such conventional techniques have the following problems.

■: When trying to measure the distance between two points, place a ruler on the scale corresponding to the scale of the nautical chart between the two points, and when trying to measure the direction, use a protractor. 6 Therefore, this method is difficult to manage and use because it requires aligning rulers for each scale.

■: Because rulers and protractors are used, their accuracy is affected by their accuracy and usage conditions, and measurement accuracy is also poor.

■Even with a knee-sized nautical chart, errors depend not only on measurements but also on the chart projection method, and the appearance of errors differs depending on the measurement location.

The present invention has been made in view of the above-mentioned problems of the conventional technology, and its purpose is to calculate the distance and direction between two points in a position display using a measurement point input means. The present invention provides a position display device that is capable of measuring information in the position display with high accuracy by inputting the input value in consideration of the position, scale, etc., and calculating the input value using a calculation means.

Means for Solving the Problems> In order to achieve the above objects, the present invention provides a large display device capable of displaying position information of a ship on an on-board nautical chart, and a distance and direction measuring point on the large display device. a device coordinate inverse conversion unit that inputs the information of the measurement point and converts it into a position in a projection coordinate system; various projection inverse converters that convert into latitude and longitude corresponding to the coordinates; a start point reset switch connected to the various projection inverse converters to take the distance measurement starting point position; information from the start point reset switch is guided to calculate the distance between the two points. a distance/direction calculation unit that calculates the distance and direction of the distance 1i? / A distance/azimuth display section that displays the distance and direction between two points on the large display based on the calculation results from the azimuth calculation section.

<Operation> A measurement point of distance and direction given by coordinates on the large display is input into a large display that can display various positions on the nautical chart using a measurement point input means. This measurement point input information is
At the same time, the information is guided to the device coordinate inverse conversion section, where it is converted into position information in the projection coordinate system, and then output. The position information in this projection coordinate system is input to various projection inverse converters, converted into latitude and longitude, and then output to a start point reset switch for importing the ranging start point position. The distance measurement start point and end point from this start point reset switch are input to the distance/azimuth calculating section, the distance and direction between the two points are calculated, and then output to the distance/azimuth display section. Therefore, the distance and direction display section displays the input distance and direction information on the large display. As described above, the distance and direction between two points can be measured and displayed with high precision.

<Example> Examples will be described with reference to the drawings.

The figure shows a block system diagram of a position display device that is a specific embodiment of the present invention.

In FIG. 1, reference numeral 1 is a large display device that can display various positions on a nautical chart (not shown). Reference numeral 2 denotes a cursor moving means that can move a cursor for measuring the position displayed on the large display 1 between measurement positions. This cursor moving means 2 outputs the amount of cursor movement (measured amount) based on distance and direction by moving the cursor from the start point to the end point on the large display 1 based on the position displayed on the large display 1.゛Cursor position input means (or cursor movement amount input device, hereinafter referred to as "trackball") 2a consisting of a track hole, mouse, joystick, keyboard, etc. and the measured distance from the track pole 2a in coordinates on the large display 1 The cursor position calculation section 2b calculates the cursor position by inputting (the amount of cursor movement), and the cursor position information (
and a cursor display section 2c that moves and displays a cursor on a large display by inputting χe, ye). code 3
is a cursor moving means 2 based on coordinates on a large display.
A device coordinate inverse transformation unit that outputs position information (Xε, YE) of the projection coordinate system based on the cursor position information (i.e., measured value) and screen origin position information (condition information such as screen center position and scale) given from be. 4 inputs the position information of the projection coordinate system from the device coordinate inverse conversion unit 3, and converts it according to the projection to obtain the latitude (r) and longitude (
λ) and outputs the result.

This various projection inverse conversion means 4 includes various projection inverse conversion sections (gradient projection inverse conversion section 4a1..., plan projection inverse conversion section 4a1..., plan projection inverse conversion section 4a1... A section 4a11.) 4a is prepared, and a selection switch SW+sw2 is switched by a projection inverse conversion section switching operation section 4b according to the projection method to be used. 5 is the distance measurement information <tp from the various projection inverse conversion means 4 to the common terminal.
, λ) is derived to capture the starting point position of distance measurement.
This is a start point reset switch consisting of an FF (reset) contact mechanism (in this case, the ON contact is configured to take in the distance measurement start point 6, so as a result, the OFF contact takes in the distance measurement end point). Reference numeral 6 denotes a distance/direction calculation means to which the start point reset switch 5 is connected and calculates and outputs the distance and direction between two points from the distance measurement start point information or the distance measurement end point information. This distance/direction calculation means 6 inputs distance measurement starting point information and generates distance measurement starting point position information (FS).

The distance measurement start point position information output section 6a outputs the distance measurement start point position information (λS), and the distance measurement end point position information (rE) inputs the distance measurement end point position.

The distance measurement end point position information output unit 6b outputs the distance measurement end point position information and the distance measurement end point position information that outputs the distance measurement end point position information.
DIST) and a distance/direction calculation unit 6C that calculates the direction (BRNG) between the two points. This is a distance/azimuth display section provided to display distance and direction on the large display 1.

With this configuration, the distance and direction between two points can be measured and displayed with high precision. The operation of these will be explained below.

(a) Information such as the position to be measured on the device coordinates, which is a coordinate system dependent on the two-person display 1, is sent to the trackball 2a.
The cursor position (y
e, 11e) are sequentially obtained by the cursor position calculation unit 2b. Here, the cursor position calculation unit 2b calculates ye (n)=χe (n-1> +fx (Δχ
)−(+)? /e (n)=? Je <n-1) 10f
The cursor position in device coordinates, which is the coordinate system of the large display, is calculated from the arithmetic expression based on y (Δy) (2). However, (D, in equation (2), Δχ, Δy are the amounts of cursor movement in the χ and υ directions input from the trackball 2a, and fy, fy are the amounts actually moved on the device coordinates with respect to the amount of cursor movement. The cursor position, which is the index to be moved by the trackball 2a, is displayed, for example, as a "cross mark" on the large display using the cursor display section 2C.

(b): The cursor position (ye + 1/e) sequentially obtained by the cursor position calculation unit 2b is simultaneously guided to the device coordinate inverse transformation unit 3, and is converted to the nautical chart and thread control depending on the projection method based on the screen origin position information. is converted to the cursor position. Here, the device coordinate inverse transformation unit 3 converts XE=K(CO8θ(
χe−χ0) +stnθ<ye'! 10 ) ) 10Xo −(
3) YE =K (=s in θ
χ e −χ . )+cosθ(ye '10)
)+Yo... From the calculation formula based on (4), the cursor position in device coordinates is converted to the cursor position in the chart coordinate system (XE
, YE). However, in equations (3) and (4), χo + 'J.

is the same as the center of rotation on the device coordinates (chart origin To set the position of and, the position of is also the center of rotation.Also, the position of XO.

Yo is the chart origin. Also, let θ be the coordinate rotation angle. At this time, display the nautical chart on the large display with the north direction at the top (N0RTH
-UP), it is also possible to rotate the north direction of the chart and the upper direction of the large display 1 by θ degrees. In addition, K should be used as an expansion coefficient between coordinates, since this does not correspond to the length "1" on the chart or the length "1" on the device coordinates, so the coefficient K should be used to absorb this. I have to.

(C): The converted cursor position information (XE, YE) is guided to various projection inverse conversion means 4 according to the projection method, and is converted into cursor longitude (r) and cursor latitude (λ).
The figure shows the switch status when using projection or gradual projection. In this various projection inverse conversion means 4, a projection inverse conversion section 4a is prepared for each projection to be used, and a selection switch is changed according to the projection to be used. Since it is very complicated, for the purpose of simplifying the explanation, we will show the calculation formula for the plane projection inverse transformation.

λ=λo 10 (XE XO) / (l e
・”(5)9’=9’o + (YE YO) /
Na - (6) However, lo represents the length of longitude 1'' on the nautical chart, Na represents the length of latitude 1- on the nautical chart,
(le-((Ro cos9Dt)/(1-112s in2Pm)")(π/(180
X60))・S...(7)Na-[(Ro (1(
12))/(1/2sin29D11L)'◆2](π/(180
It can be expressed as X60)l ・S...(8). However, T is the latitude, S is the scale of the nautical chart, and RO is the equatorial radius. Furthermore, when the earth's oblateness is f, the length l is N' =/ (2-/)
...Represented by (9).

(d): The converted cursor longitude and cursor latitude are
Passing through the start point reset switch 5, the distance/direction calculation means 6
guided by. At this time, the distance measurement end point position (Tε, λ
E) is inputted to the distance/azimuth calculation section 6C via the distance measurement end point position information output section 6b.

If you want to change the distance measurement start point, turn on the start point reset switch 5 momentarily and send the distance measurement start point position information (9Ds + λ) to the distance measurement start point position information output section 6a.
s). After this, the starting point reset switch 5 returns to OFF measurement again.

(E): When the start point reset switch 5 is turned on, the cursor display section is also notified (displayed by a broken line), and the cursor display section 2C shows the cursor position at that point (XE).

11E) is fixedly displayed as the measurement starting point.

(to): The distance and direction calculation unit 6C uses the distance measurement starting point position information (
9O9, λS) and ranging end point position information (90E.

λE), the direction and distance between the two points between the distance measurement start point and the distance measurement end point are determined by the following calculation formulas 〇〇) to 〈18) in consideration of the flatness of the earth 4Af using gradual latitude navigation, and the distance is
It is output to the direction display section 7. Equatorial radius RO and earth oblateness f
When the multiplier that depends on
-(3/4)・Ro(1-f)2/(2-f>)・
...01) is obtained. Here, when the longitude difference between the two points is 1, this K is the difference between the ranging start point/end point position outputs (λE7λS), 11 K, =λE−λS. However, 0≦ and ≦π. Also, both latitudes (
When the constant that depends on ψi: + F s ) and the Earth's oblateness f is set to 2, K2 = lTL (c o 590s (1+s i
nPE)/C089'E (1+5in5oS)ltenf
(f+2) (s i n9'E-5i n90s
) −(12). However, Ts and PE are distance measurement start point/end point position outputs. Here, if we express 2 in K and 3 as a constant, then K3== (22 in K, 2 +) I/2
...(13). Here, 19'E
9'sl<0.31111. And in lK3/, l≦(
The distance DIST when 2 > 112 (K 1 to 0) is DIST = [Ro-x, -cosqys/(1+f(/
-2) sin29's M'] (1 in K3/)...
・(14) becomes. The distance DIST under conditions other than the above is DI
5T-= (K3/K2)(CI-+ (9'E
9's) 10C2-(s in!'s -CO
5956s in9'E-c OS9'E))
・=(15). Also, the direction BRNG between two points is
BRNG=arcsin(K+/3) −(ie)
becomes. However, when K2≧0 and BRNG<O, BRN
G=BR'NG+2π...(17) Also, when K2 is 0, BRNG=π-BRNG...(1
8).

(G): The distance and orientation display section 7 digitally displays measured values regarding distance and orientation on a large display based on the input information as described above.

Note that the explanatory formulas for the various calculation units described above are not limited to these. For example, in order to reduce the calculation load, you may use a simplified formula that treats the earth as a sphere (however, this will naturally result in a corresponding decrease in accuracy).
.

<Effects of the Invention> Since the present invention is configured as described above, it produces the following effects.

■: There is no need for a ruler based on the scale, and it can be adapted to any scale.

■: Measurement errors depending on the projection method are eliminated, allowing highly accurate measurements.

[Brief explanation of drawings]

The figure is a block system diagram of a position display device that is a specific embodiment of the present invention. 1...Large display unit, 2...Cursor moving means, 3.
...Device coordinate inverse conversion unit, 4...Various projection inverse conversion means, 5...Starting point reset switch, 6...Distance #/azimuth calculation means, 7...Distance and direction display section. 5

Claims (1)

[Claims] A large display that can display the position information of the ship on the onboard nautical chart, a measurement point input means that can input measurement points of distance and direction on the large display, and a projection coordinate system by inputting the information of the measurement points. A device coordinate inverse conversion unit that converts into a position, a various projection inverse conversion unit that converts the position information of the projection coordinate system converted by the device coordinate inverse conversion unit into latitude and longitude corresponding to various projections, and the various projection inverse conversion units a starting point reset switch to which is connected and receives the distance measurement starting point position, a distance/direction calculation section to which information from the starting point reset switch is derived to calculate the distance and direction between the two points, and from the distance/direction calculation section. A position display device comprising: a distance/direction display section that displays the distance and direction between two points on the large display based on the calculation results.