JPH0612262B2 - Depth display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Explanation] includes (a) technical field (b) conventional technology and its drawbacks (c) purpose of invention (d) outline of invention (e) structure of invention (f) invention The effect (g) is composed of examples.

〔Explanation〕

(a) Technical Field The present invention relates to a depth display device capable of obtaining and displaying a depth at an arbitrary point near a ship.

(b) Conventional technology and its drawbacks Conventionally, when navigating and maneuvering fishing boats, marine research vessels, etc. It is necessary to accurately recognize the depth near the own ship when sailing or stopping near the destination in order to locate the own ship by comparison, check the depth near the destination such as casting net, and search for the destination based on the depth. Conventionally, a contour map is used, in which the contour lines are color-coded according to the depth, the solid line and the broken line are used according to the depth, or the depth numbers are written to make it easy to stop the depth.
There was a problem that the accurate depth at the desired point could not be read immediately.

(c) Object of the Invention The object of the present invention is to provide a depth display device capable of displaying the depth of an arbitrary point around the ship and displaying the depth of the point, and confirming the depth accurately and quickly. To do.

(d) Outline of the invention [1] Storage of depth data First, in order to obtain the depth of the point P, the bathymetric data around the ship is previously drawn as a contour map, depth map (simply the depth is discretely entered on the map), etc. Read from and memorize. Hereinafter, a method of storing the contour line data in a readable storage device using the contour map will be described. The following storage methods are available.

Use the seafloor topographic map issued by the Japan Coast Guard.

The contour lines on the seabed topographic map are read by a reading device (a device that measures the position on a plane such as a digitizer), and the positions are stored in a storage device together with the depth of the contour lines. A magnetic tape, a magnetic drum, a magnetic disk, or the like is used as the storage device.

Positioning and sounding are performed using the positioning device and sounder installed on the ship.

A ship sails finely in the sea area where the contour map is required, and the positions and depths of many points are measured. Using these measured values, the computer obtains the iso-depth position, creates an iso-depth map, and stores it in the storage device.

[2] When Determination point P depth D _P of the point P is on the bathymetry will depth D _P of the depth of the contours are determined. Therefore, a method for obtaining the depth when the point P is located between the contour lines will be described.

FIG. 2 is an example of a contour map and is drawn in North Up. Point P is surrounded by four contour lines a, b, c and d. The depths of a and c are equal to D _e1, and the depths of b and d are also equal to D _e2 . Draw some lines (4 in the figure) that pass through point P. 4 lines passing through point P are 0-4, 1-5, 2
-6 and 3-7. 0-4 runs north-south, 2-6 runs east-west. 1-5 is northeast-southwest, 3-7 is northwest-
Drive southeast. The distances between the points where each line crosses the contour line and the point P are l ₀ , l ₁ , l ₂ , l ₃ , l ₄ , l ₅ , l ₆ and l ₇ .

The following is an example of an equation for obtaining D _P.

Here, _dek is the depth of the contour line that the straight line Pk crosses for the first time. In FIG. 2, d _e0 = d _e1 = d _e4 = d _e5 = d _e7 = D _e1 and d _e2 = d _e3 = d _e6 = D _e2 . Equation (1) gives weights that are inversely proportional to the distances from the eight directions, and weighted averages the depth of each point on the contour line.

Here, considering a case where D _P is simply obtained using only one straight line 2-6, D _P = {(d _e2 / l ₂ ) + (d _e6 / l ₆ )} / {(1 / It can be obtained as l ₂ ) + (1 / l ₆ )}. For example, if l ₂ : l ₆ = 3: 4, then D _P = {(d _e2 / 3) + (d _e6 / 4)} / {(1/3) + (1/4)} = (4 * d _e2 + 3 * d _e6 ) / 7, and for example, d _e2 = 120 m, d _e6 = 130 m
Then, D _P = (4 * 120 + 3 * 130) m / 7 = 124m is obtained. By increasing the number of the straight lines and taking the respective directions in different directions, it is possible to accurately obtain the depth at the specified position of the seabed undulating in the three-dimensional direction.

In this way, the depths of contour lines that a plurality of straight lines cross are weighted and averaged with a weight that is inversely proportional to the distance from the designated position to the contour lines, so that the depth changes smoothly even if point P moves.

D _P can be _calculated by a relatively simple formula. (E.g., to determine the point P from the equation of the plane passing through the three points, and requires a number of steps to solve the equations.) D _P is the same or an intermediate value between the depth of the depth contour around the point P , The depth value of the contour line is not significantly exceeded, and a large error does not occur.

There are advantages such as.

In addition to the method of obtaining D _P from the depths and distances in eight directions around the point P based on the above equation (1), there is the following method.

It is calculated from the depth and distance in the J direction (J is an integer other than 1 and 8) using the equation (1). That is, other than 8 directions, 2 directions, 3 directions, 4 directions, and 16 directions may be used.

Using the formula (1), it is calculated from the depth and distance in the I direction (I is an integer other than 1), and the direction other than north is not used as the reference, for example, the direction of the point on the contour contour closest to point P is used as the reference. To do.

Using the formula (1), it is calculated from the depth and the distance in the I direction (I is an integer other than 1) and the circumference of the point P in the formula (1) 36
0 ° may not be equally divided every 45 °, but may be illegally divided. For example, D _P is calculated by selecting the four points closest to the four contour lines.
In this method, a depth map whose depth is discretely known may be used instead of the contour map.

[3] Method for designating point P There are the following methods for designating the position of point P.

Display the contour map and specify point P on the contour map. Depending on the designation method, (I) direction and distance designation from own ship, (II) direction and distance designation from arbitrary target (2 bearing directions are designated respectively, (Including the cross-bearing method in which the point of intersection of the azimuth line is the point P), (III) specifying the latitude and longitude, (IV) specifying the position on the display, and so on.

Point P is designated on the screen of the track recorder, radar or sonar. In this case, the contour map may not be displayed.
This is also classified into (I) to (III) depending on the designation method, and also according to the position on the display (track recording device, radar, sonar).

Point P is specified only by the setter without displaying the contour map. This also depends on how you specify (I)-(II
I) etc.

In addition, in (I) and (II) of ~, it is necessary to know the latitude and longitude of the own ship, and the latitude of any target,
The longitude must also be known from the direction and distance from the ship.

As described above, the depth data around the ship can be stored in advance, and the depth D _P can be automatically obtained by designating an arbitrary point around the ship and displayed on the display.

(e) Structure of the Invention FIG. 9 is a structure diagram of the present invention. In FIG. 9, the bathymetric data storage means 101 prestores bathymetric data at a plurality of points within a certain sea area together with position information of the points. The position designating means 102 designates the position of an arbitrary point within a certain sea area. The bathymetric data reading means 103 reads out bathymetric data of a plurality of points which are close to the position designated by the position designating means 102 and in a predetermined direction from the designated position from the bathymetric data storage means 101. Distance extraction means 104
Calculates the distance from the designated position to each position of the plurality of points based on the position information of the plurality of points read by the bathymetry data reading unit 103 and the position information of the designated position. The weighted average value calculation means 105 calculates a weighted average value by weighting the bathymetric data at each position with a coefficient inversely proportional to the distance from the designated position to each position of the plurality of points. Then, the numerical value display means 106 numerically displays the value calculated by the weighted average value calculation means 105 as the depth at the designated position.

(f) Effects of the Invention As described above, according to the present invention, the depth of a point is immediately calculated and displayed numerically just by designating the point, without calculating or reading the depth on the depth map. Depth confirmation can be performed accurately and quickly. In addition, the bathymetric data storage means can obtain the depth at the specified position with high accuracy even if the depth data is stored in the lateral direction (XY direction, etc.) with a relatively low resolution.

(g) Example This example is constructed under the following conditions.

(1) Read the seafloor depth from the contour map and read the seafloor depth R in advance.
It is stored in the OM 20 (see the above [1]-).

(2) The depth D _P is calculated from the distances and directions in eight directions based on the equation (1) (see the method of [2] above).

(3) Point P is specified by setting the distance and direction from the ship's position (see [3]-(I) above).

(4) the depth D _P is the depth indicator and depth contours view, the position of the ship and specified point is displayed on the CRT screen.

FIG. 1 is a schematic configuration diagram of a depth display device of the present invention.
First, as a premise, depth data is stored in advance according to [1]-. A positioning device 1 measures the latitude L _as and the longitude L _os on the map of the own ship position (point S). The latitude L _as and the longitude L _os by this positioning device are converted into position coordinate data (x _s , y _s ) by the coordinate converter 4. Reference numerals 2 and 3 are setters for setting the distance L and the direction B from the point S to the arbitrary point P with the own ship position S as a reference. The position coordinate (x _p , y _p ) of the point P is obtained by the coordinate converter 5 from the constant value of the setting device and the coordinates of the own ship position. Reference numeral 6 denotes a seafloor depth storage ROM that stores the depth of each contour line as shown in FIG. 2 at XY coordinate positions. Using this ROM, the depth of point P is obtained under the control of the CPU 7.

The depth D _P is obtained by the method of [2] above. When the position coordinate (x _p , y _p ) of the point P is obtained and given to the ROM 6, a line is drawn in eight directions centering on the coordinate. A distance _l 0 to l ₇ at the intersection of the respective contours, depths _d e0 to d
Search _e7 . Next, the depth D _P is calculated by the equation (1). The depth _P is displayed on the depth indicator 9 through the I / O 8. By specifying the position of an arbitrary point P by the above operation, the depth of that point can be obtained and displayed numerically.

3A and 3B show specific examples of the depth display device. Correspondence between the constituent elements of the present invention and each part in FIGS. 3 (A) and 3 (B) is as follows.

FIG. 4 is an example of a contour map shown on the CRT 10 of FIG. 3 (A). In the figure, display range: each side L ₀ [mile] The display screen is a square, and the contour map is north-south and east-west L ₀
Display [miles] range in North Up.

Display screen primes: n × position of n display point P on the _screen: the position of (x _{p, y} p) Display ship on the screen (S _{point): (x s, y s} ) the center position of the display depth contour diagram latitude on a map (O point), longitude _{position: (L aO,} L _OO) latitude on ship map, longitude _{position: (L as,} L _os) distance from point S to the point P: L [miles ] Direction of point P viewed from point S: B [°] This direction is defined as a clockwise angle from the north position.

The seafloor depth ROM 20 stores the seafloor depth on the contour lines of north-south and east-west L ₀ [mile] centered on the point O on the map.

FIG. 5 shows the structure of the ROM 20. The number of storage elements is n (dots) × n (dots) × 1 (bits) in order to store the depth of n × n points corresponding to each pixel on the CRT 20. That is, the ROM 20 stores the depth d _e at the point where the contour line exists within the n × n point.
Not all the n points have the contour lines, and a constant value dm that is not related to the display of the CRT ₁₀ is stored at the points without the contour lines. It should be noted that the number of memory points n × n in the ROM is the same as the number of pixels n × n on the display screen.
This is because the OM is used both for displaying the contour lines and for searching the depth.

The contour lines stored in the ROM 20 are connected vertically and horizontally for depth search as shown in FIG. 6 (A). The cells in the figure indicate each pixel, and the circles indicate the locations where depth data corresponding to contour lines are stored. In FIG. 2B, since the contour lines are connected only in the diagonal direction, when the depth search shown in FIG. 2 is performed, the contour line may be missed in the diagonal search. It cannot be used when performing a search.

By the way, the positioning device 11 shown in FIG. 3 (B) is a loran, an omega, a decker, an NNSS, etc., and has a latitude L _{as of} its own ship position,
The longitude L _os is output in minutes. The coordinate conversion circuit for the position of the ship is a subtractor 12, 13, 18, 19 and a multiplier 14-1.
6, cos ROM 17 is included. Subtractor 12,
13 finds the positional difference on the map between points O and S shown in FIG. Since the O point position (L _ao , L _oo ) is also input in minutes, the output unit of the subtracter 12 and the multiplier 14 is minutes. The latitude difference of the output of the subtracter 12 is multiplied by the unit pixel number in the y direction (n-1) / L ₀ by the multiplier 15, and this is subtracted from the y position (n-1) / 2 of the O point by the subtractor 18. Y is calculated
Find the coordinate y _s . On the other hand, co
s After multiplying the cos output of the ROM 17 (coefficient value of distance with respect to longitude difference by latitude of point O) by the multiplier 14,
The unit pixel number in the x direction (n-1) / L ₀ is multiplied by the multiplier 16, and this is subtracted by the subtracter 19 at the x position (n−) of the O point.
1) / 2 is subtracted to obtain the x coordinate x _s .

The setters 21 and 22 shown in FIG. 3A are for designating the distance L and the direction (angle B) of the point P from the point S, respectively. The position coordinate conversion circuit of the point P is the multipliers 23 to 2
5, 27, subtractors 26, 28, cos ROM 29 and si
It is composed of n ROM 30. Multiplier 23 and cos R
The OM 29 obtains Lcos B, and the multiplier 27 multiplies it by the number of unit pixels in the y direction (n−1) / L ₀ to obtain the difference in the y direction. This difference is passed through the subtractor 28 to the y coordinate y of the S point.
Subtract from _s to obtain the y coordinate y _p . On the other hand, the multiplier 24
And sin ROM30 find Lsin B and multiply it by multiplier 2
X by multiplying the unit pixel number (n-1) / L ₀ in the x direction by 5
Find the difference in direction. This difference is subtracted from the x coordinate x _s of the S point via the subtractor 26 to obtain the x coordinate x _p .

Next, the configuration and operation for obtaining the depth D _P at point _P will be described.

To determine the depth _{D P,} first (1) of _{d ek} and _{l k}
Are calculated by hardware, and the values are calculated by the CPU 31 according to the equation (1). The hardware configuration will be described below.

FIG. 8 is a timing chart at the depth search.

The CP circuit (clock pulse generation circuit) 32 is a pulse generator that generates a pulse having a period t ₀ . t ₀ corresponds to the display time of one pixel on the CRT screen. k counter 3
The 3, l counter 34 stores the contour lines in eight directions from point P in ROM
Counters for searching from 20 stored data, which are up-counters of octal and n-ary, respectively. C of each part in the figure
K, CLR, C, D _i and D ₀ indicate clock input, clear input, carry output, data input, count value or data output of the counter. The ROM 35 outputs the positional difference Δx, Δy on the CRT screen between the point P and the point for searching the contour line based on the count values of the k counter 33 and the l counter 34. Position difference [Delta] x, [Delta] y are added by adders 36, 37 _x p, the _{y p,} is introduced into the switching device 72.

The ternary counter 38, the decoder 39, and the switch 43 are _deek
And a circuit for generating a timing pulse for obtaining _lk . The ternary counter 38 is an up counter that counts up at the rising edge of the clock of the CP circuit 32. The delay circuit 44 sets the clock of the CP circuit 32 to t _0.
In the circuit for delaying by / 4, the output values 1 and 2 of the decoder 39 are introduced into the switch 43 through the AND circuits 41 and 42 together with the output of the delay circuit 44. The k counter 33 and l counter 34 count up at the rising edge of the output pulse of the delay circuit 44. The output value 0 of the decoder 39 is the delay circuit 4
It is introduced into the latch 63 via the AND circuit 40 together with the output of 4. The output of the delay circuit 44 is the inverter 4
It is input to the latch 64 via 5.

The latch 63 stores the output value of the ROM 20 at the rising timing of the output pulse of the delay circuit 44. When the clock of the CP circuit 32 is at H (high) level, the switch 7
The movable contact 2 is tilted to the opposite side of the figure, and the depth at the point indicated by the adders 36 and 37 is read, and the depth is stored in the latch 63 at the rising edge of the output pulse of the delay circuit 44.

The comparator 71 determines whether the depth data stored in the latch 63 is the depth on the contour line. Based on this determination result, the contact of the switch 43 is switched to change the k counter 33,
The counting operation of the l counter 34 is controlled.

Next will be described an operation for obtaining the _{d ek} and _{l k.}

FIG. 7 shows the contour line data in the ROM 20. Since as described above ROM20 stores a submarine depth _{d e} and _{d m} corresponding to each pixel of the CRT screen, the position of the point P (x
_{p, y p)} outputs a _{d e} or _{d m} of the input point P. If the data d _m is output, a contour line is searched in 8 directions centering on the point P. In FIG. 7, 0, 1,
The numbers 2, 3, ... Show the count value of the l counter 34. The direction of this count value corresponds to one of the eight directions.
For example the count value of the k counter 33 is 0, i.e. when k = 0 looks for bathymetric accordance with the count value of l counter 34 northward, is d _e0 than its depth contour depth when contours are found, also the l counter 34 at that time ₁₀ is determined from the count value. When d _e0 and l ₀ are obtained, the k counter 33 counts up by 1 and the count value becomes 1. On the other hand, the l counter 34 is reset and becomes 0. Then, the l counter 34 counts, and this time, a contour line search is performed in the northeast direction to obtain d _e1 and l ₁ .
The above operation is performed until the count value of the k counter 33 reaches 7, and d _{e0 to} d _e7 and l _{0 to} l ₇ are obtained.

As described above, when the count value of the ternary counter 38 is 0, the depth is read from the ROM 20 and the depth is stored in the latch 63. The comparator 71 determines whether the depth transferred to the latch 63 is on the contour line.
When the count value is 1, data reading is notified through an interrupt line between the switch 43 and the CPU 31. CPU
31 thereby causes the d of latch 63 to pass through input device 48.
_ek is read, and at the same time, the count value k of the k counter 33
And the count value l _k of the l counter 34 is read. The switching device 47 introduces the l counter 34 which is introduced into the input device 48 according to whether the count value k of the k counter 33 is odd or even.
Switch the count output of. Since the count value of the k counter 33 when the odd is the direction other than cardinal, to read the l _k was 2 ^1/2 times the count value of l counter 34 than when the even. When the count value of the ternary counter 38 is 2, if the depth transferred to the latch 63 is on the contour line, the k counter 33 is incremented and l
The counter 34 is reset. When the depth is not on the contour line, the l counter 34 is incremented.

The CPU 31, the RAM 49, and the ROM 50 form a calculation unit that calculates the expression (1). The arithmetic unit _d e0 _{to d} entered through the input device 48 at _e7, l 0 ~l ₇ from (1) to calculate the depth _{D P} by. When the depth D _P is calculated, it is sent to the depth indicator 52 via the output device 51 to display the depth.

The x counter 57 and the y counter 58 are n-ary up counters for reading the storage depth of the ROM 20 in synchronization with the scanning of the CRT 10 and displaying contour lines on the CRT screen. These counters define the coordinates (x, y) on the display screen. As shown in FIG. 8, when the clock of the CP circuit 32 is at L (low) level, the movable contact of the switch 72 is tilted to the right as shown in the figure, and the x counter 57 and y counter 5
The depth of the coordinate designated by the count value of 8 is read from the ROM 20. The depth read from the ROM 20 is the inverter 4
It is stored in the latch 64 at the rising edge of 5 outputs. The color conversion ROM 53 is a color conversion circuit that performs color conversion to display a color corresponding to the data stored in the latch 64 on the CRT. The output of the ROM 53 is sent to the CRT 10 as red (R), green (G), and blue (B) signals through the D / A converters 54 to 56. 61 and 62 are y deflection coils of the CRT 10 and x
Deflection coils, and 59 and 60 are respective deflection amplifiers.

The AND circuit 65 and the comparison circuits 67 and 68 are circuits for displaying the position of the point S on the CRT. Comparing circuits 67 and 6
8 is the output value y of the subtracters 18 and 19 shown in FIG.
_s, by comparing the count value of _{x s} and y counters 58, x-counter 57 calculates a signal timing value of the x-counter 57, y counter 58 becomes the display coordinates of the point S _(x s, _{y s)} ROM 53 To enter. AND circuit 66, comparison circuit 6
Reference numerals 9 and 70 are circuits for displaying the position of point P on the CRT. The comparator circuits 69 and 70 compare the output values x _p and y _p of the subtracters 26 and 28 with the count values of the x counter 57 and y counter 58, and the values of the x counter 57 and y counter 58 are the display coordinates of the point P. A signal having a timing of (x _p , y _p ) is obtained and input to the ROM 53. By determining the display coordinates of the points P and S, as shown in FIG. 4, on the CRT screen,
Display P and S points together with the contour map. When only the depth D _P is displayed on the depth indicator 52, the CRT 10 does not have to be used to display the contour map or the points P and S. On the contrary, the depth D _P may be displayed on the CRT screen without using the depth indicator 52. Instead of the CRT, a display such as liquid crystal, plasma or LED may be used as the display.

In the above embodiment, the ROM 20 is used to store the contour data.
Is used, but the contour line data is written in the RAM using the RAM and the CPU, and _{de 0} ~ is controlled by the CPU.
The search of d _e7 , l _{0 to} l ₇ and the depth D by the equation (1)
The calculation of _P may be programmed.

Further, in the above-described embodiment, the point where the depth is to be obtained is specified by the direction and the distance from the own ship position, and the seabed depth RO which is two-dimensional XY rectangular coordinates is used as the bathymetric data storage means.
Although M20 is used, the point where the depth should be obtained may be designated by the values of latitude and longitude, or a memory in which bathymetric data is stored as latitude and longitude coordinates may be used.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a depth display device of the present invention. FIG. 2 is a diagram for explaining the principle of the present invention. 3 (A) and 3 (B) are views showing a specific example of the depth display device, FIG. 4 is a view showing one display example of a contour map, and FIG. 5 is a configuration diagram of a seabed depth storage ROM. 6 Figures (A), (B)
Is a diagram for explaining a storage state of the contour lines in the ROM, FIG. 7 is a storage coordinate diagram of the ROM for explaining the depth search in the depth display device of FIG. 3, and FIG. 8 is a depth of FIG. 6 is a timing chart for explaining the operation of the display device. FIG. 9 is a block diagram of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-58-76783 (JP, A) JP-A-58-79178 (JP, A) Practical application Sho-50-928 (JP, U)

Claims (4)

[Claims] 1. A bathymetric data storage means for pre-storing bathymetric data at a plurality of points within a certain sea area together with positional information of each point, and a position designating means for designating a position of an arbitrary point within the certain sea area. A sounding data reading means for reading, from the sounding data storing means, sounding data of a plurality of points which are close to a position specified by the position specifying means and in a predetermined direction from the specified position; and the plurality of points from the sounding data storing means. Based on the position information of the above-mentioned position information and the position information of the above-mentioned designated position, the distance extraction means for obtaining the distance from the designated position to each position of the plurality of points, and the inversely proportional to the distance from the designated position to each position of the plural points Weighted average value calculation means for calculating a weighted average value by weighting the coefficient to the bathymetric data at each position, and calculation by the weighted average value calculation means. Depth display device having a numerical display means for numerically displaying the value as the depth of the designated position. 2. The depth display device according to claim 1, wherein the position of the arbitrary point is designated by a direction and a distance from the own ship position. 3. The depth display device according to claim 1, wherein the position of the arbitrary point is designated by latitude and longitude. 4. The depth display device according to claim 1, 2, or 3 wherein said bathymetric data is based on data of a contour map.