JPS6245171Y2 - - Google Patents

Description

[Detailed description of the invention] Recently, ultrasonic tidal current meters have come into widespread use, replacing the Eckman-Metz meters that have been conventionally used as tidal current measuring devices. Ultrasonic tidal current meters simply detect the Doppler shift component of ultrasonic waves reflected from the measurement target depth, so they are convenient because they can instantaneously measure tidal currents at a desired point. Usually, the display is designed to display the direction and velocity of the current as a vector or as a digital number. However, this is only an instantaneous display, and it is not suitable for understanding the distribution of tidal currents in a certain sea area, such as by surveying the tides, as it requires a lot of mental effort.

This proposal displays the ship's wake S as well as the direction and magnitude of the current T ₁ , T ₂ , T ₃ . . . in a single color or in multiple colors on a cathode ray tube display, for example, as shown in Figure 3. .

In this way, the tide can be determined at a glance, and fishing grounds can be selected quickly and reliably.

The present invention will be explained below based on examples.

In FIG. 1, 1 is an indicator for displaying the ship's wake and the magnitude and direction of the tidal current, and for example, a Bracan tube indicator is used.

FIG. 3 shows an example of the display, where S is the ship's track T is a vector display line of the tidal current at each point.
Further, _L1 indicates a latitude line, and _L2 indicates a longitude line, and the display range of the own ship's position latitude and longitude line is movable.

The display contents displayed on the display 1 are stored in the display memory 2, and the stored contents are repeatedly read out and displayed.

In the display memory 2, storage elements are arranged corresponding to each pixel of the display 1, and the storage contents of each storage element are sequentially read out by a horizontal scanning counter 3 and a vertical scanning counter 4.

Horizontal scan counter 3 counts clock pulses from clock pulse source 5. An output pulse is sent to the vertical scanning counter 4 every time the same number of clock pulses as the number of pixels in the horizontal direction of the display 1 is counted. The vertical scanning counter 4 counts the output pulses of the horizontal scanning counter 3 and sends out an output pulse every time it counts the same number of pulses as the number of pixels in the vertical direction of the display 1.

The respective output pulses of the horizontal scanning counter 3 and the vertical scanning counter 4 are sent to the horizontal/vertical scanning circuit 6. The horizontal/vertical scanning circuit 6 scans the pixels of the display 1. For example, when a cathode ray tube display is used, the electron beam scans the pixel positions corresponding to the count values of the horizontal scanning counter 3 and the vertical scanning counter 4. Further, each count value of the horizontal scanning counter 3 and vertical scanning counter 4 is sent to the display memory 2, and the storage contents of the storage element corresponding to each count value are read out. The read stored information is sent to the display 1 and displayed. By that,
The contents of the memory elements corresponding to each pixel of the display 1 are displayed.

While the information stored in the display memory 2 is displayed on the display 1 as described above, the writing of the stored information is performed by the microprocessor 7 (hereinafter referred to as CPU).

First, the own ship position is written based on position data measured by the navigation device 8.

As the navigation device 8, for example, a Loran receiver, an Omega receiver, an NNSS receiver, a dead reckoning device, etc. are used,
It measures the navigational position of its own ship and sends out the measured position as, for example, latitude and longitude data. Navigation device 8
The latitude and longitude data sent by is sent to the CPU 7 via the interface 9.

The CPU 7 receives the latitude sent from the navigation device 8;
The display screen of display unit 1 (second
Perform coordinate transformation to the corresponding position on the figure). In this coordinate transformation, for example, a position on the display screen is made to correspond to a specific latitude and longitude position, and a position on the display screen corresponding to the latitude and longitude position measured using that position as a reference position is calculated.

The own ship position on the display screen calculated as described above is written into the corresponding storage element of the display memory 2. Further, at the same time as writing the own ship's position in the display memory 2, the CPU 7 calculates the latitude and longitude lines within a certain range including the own ship's track, and stores the latitude and longitude lines in the corresponding storage element of the display memory 2. Write.

As described above, the own ship's track S is displayed in the memory 2.
Meanwhile, the CPU 7 sends the own ship's position data measured by the navigation device 8 to the first memory 10 and stores it therein. The first memory 10 stores the position data sent by the navigation device 8 at regular intervals, and after the storage capacity is exceeded, it stores the position data while updating the old position data with new position data.

The own ship's position data stored in the first memory 10 is read by the CPU 7 when writing the own ship's track S in the display memory 2.

Next, writing of tidal flow data will be explained.
The speed of the current and the direction to the ship are measured using an ultrasonic ship speed current meter 11.
obtained by. This ship speed current meter emits ultrasonic pulses at a fixed frequency toward the depth at which the current is measured, and the ultrasonic waves reflected from the seabed and water mass create a Doppler effect that corresponds to the speed of movement of the ship and water mass. It takes advantage of what is being received. In other words, it is possible to know the speed of the water mass and the speed of the ship from the Doppler frequency, and the direction of the tidal current relative to the ship from the direction in which the sound waves are emitted. However, the orientation obtained here is a relative orientation to the ship's hull, not an absolute orientation. For this purpose, a direction sensor 12 such as a gyro compass or a magnetic compass is provided, and its output is supplied to the CPU 7 through an interface 13 along with the aforementioned ship speed information and tidal current information. CPU is navigation device 8,
The speed and direction of the current relative to the absolute direction are calculated based on the ultrasonic ship speed, the outputs of the current meter, and the direction sensor, and are stored one after another in the second memory 14. and,
The current information is read out and displayed in the memory 2 under the control of the CPU at fixed time intervals or when a read command is issued.
is stored in a predetermined location in the form of a marker. The marker is formed by a vector line segment oriented in the absolute tidal direction, and the length of the line segment is proportional to the tidal velocity. Further, the starting point position of the line segment is stored in the display memory so as to match the position of the own ship at the time of reading.

Therefore, as shown in Figure 2, in order to find the tide in the area where the southerly TS and northerly TN collide, we need to move from point A to point B and from point B in the opposite direction, as shown in figure 3. If you take a zigzag route from point C to point C, then from point C to point D, the tidal current display will be as follows.

In other words, if the ship is crossing a south-flowing ocean area, it will be displayed extending southwest from the wake, as shown by solid vector line segments T ₁ , T ₂ , . . . . When it enters the tide area, the direction of the vector line is T _n , T _n
+1, T _n +2 . . . and the speed of the current becomes slower, so the length of the line segment becomes shorter. Then, when entering the north flow area, the direction of the line is T
_o , T _o +1, T _o +2 . . ., it faces toward the northeast and its length gradually increases. When returning from point B to point C, the tidal direction is also T with the tidal area as the border.
_p , T _p +1, T _p +2, and so on. In the tidal area, the direction of the current is always irregular,
Moreover, its length becomes shorter. Therefore, if these changes in wake and tidal current markers are memorized on the screen, it becomes clear from the distribution of the tidal current vectors that the tide exists along a sea area like Q.

In the above embodiment, when calculating the tidal current vector line segment, instantaneous values at each predetermined time interval may be used.
Instantaneous values vary widely. For this, the CPU
It is better to determine the current direction and speed by taking the average value within a unit distance (represented by (ship speed x time) or (constant change in ship position)). Since the average value is automatically reduced, it is easy to understand on the display screen.

Furthermore, if the current direction is displayed in different colors, the solid line (southern current) can be displayed in blue and the dotted line (northern current) in red in FIG. 3, making it very easy to see. When tidal current data is processed by a CPU, it is sufficient to distinguish the flow velocity direction into four directions (north, south, east, and west) and color code it, and store this code in the display memory at the same time. FIG. 15 shows a color conversion circuit. In this case, it goes without saying that 1 uses a color cathode ray tube display.

As explained above, in the present invention, the tides are displayed vector-like on a cathode ray tube in relation to the wake, making it easy to detect tides and contributing to improved fishing efficiency.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing an example of the present invention;
The figure is an explanatory diagram of an embodiment of the present invention, and FIG. 3 shows an example of display on a cathode ray tube of the apparatus of the present invention.

Claims (1)

[Claims for Utility Model Registration] 1. A first memory circuit that accumulates and stores changes in the navigational position based on the measurement results of a navigation device that measures the navigational position of the own ship, and a Doppler included in reflected waves from a predetermined depth. a second storage circuit that stores measurement data of an ultrasonic current meter that measures the flow direction and flow velocity at that depth based on frequency components;
a display memory circuit that reads and stores the memory contents of the first and second memory circuits; a display that displays the memory contents of the display memory circuit; and the navigation device and the ultrasonic current meter first and second memories. What is claimed is: 1. A wake and tidal current display device, comprising a control unit that performs data processing between a circuit and a display storage circuit, and displaying a wake and a current direction and velocity along the wake as vectors. 2. The wake and tidal current display device according to claim 1, wherein the control section includes means for averaging current direction and current velocity within a unit distance. 3. A wake and tidal current display device, characterized in that the indicator comprises a color conversion circuit that converts the flow direction output of the display storage circuit into a color code according to the flow direction, and a color cathode ray tube display.