JPS61254813A - Wave observing device - Google Patents

Abstract

PURPOSE:To automatically observe wave information, such as wavelength, wave height, etc., by processing video signals taken by an image pickup device fitted to a ship toward the water surface and extracting shapes and dimensions of wave pictures in the video, and then, estimating the distance to the wave. CONSTITUTION:An image pickup device 3 is fitted to a ship 2 toward the water surface 1 and a string of taken digital signals is divided at every fixed time synchronously to each horizontal scanning at the time of image pickup, and then, dimensions of wavelengths and wave heights of waves in the pictures are found by counting the number of wave video signals or picture elements contained in each divided string. These dimensions are converted into actual dimensions by using distances between waves observed by means of the image pickup device 3 and the image pickup is repeated with the image pickup device 3 under a condition where the device 3 is set in a fixed direction. By observing the moving condition of a waveform with the lapse of time in such a way, direction of waves can be known.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a wave observation device installed on a ship, and particularly to a wave observation device equipped on a ship.
This invention relates to a wave observation device that can automatically observe wave information such as wave height and obtain accurate data.

[Prior Art] Ships navigating the ocean are obligated to report to the Japan Meteorological Agency information on sea conditions and weather in the sea area in which they are sailing. Information, i.e. wavelength, wave height,
Observations such as wave direction (direction of movement of waves) were usually done visually by sailors.

[Problems to be solved by the invention] However, the visual observation method includes problems such as the observation data is not accurate because it includes 0 individual differences, ■ Observation during stormy weather is dangerous, and ■ Night observation is not possible. There was a point.

Recently, radio wave height meters and wave radars have been developed, but the former have problems in the installation method as they need to be installed protruding forward from the bow. According to the latter, the accuracy of wavelength and wave direction data is good, but the measurement accuracy of wave height is low.

[Means for solving the problems] The present invention has been made to solve the above-mentioned problems.
An imaging device attached to the hull facing the water surface, an image processing device that processes the video signal imaged by the imaging device and extracts the shape and size of the wave image in the video, and waves observed from the WA imaging device. and a sensor for estimating the distance.

[Operation] The image-transferred digital signal row is divided into sections at fixed time intervals in synchronization with each horizontal scan during imaging, and the number of wave image signals or pixels contained in each divided row is measured. The dimensions of the wavelength and wave height on the screen are determined using the image sensor, and these dimensions are converted to the actual size using data on the distance between the imaging device and the observed waves. By repeating this and observing the movement of the waveform over time, the direction of the wave can be determined.

[Implementation @] Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1st
Figures 4 to 4 show one embodiment of the present invention, in which 1 is the wave to be observed, 2 is the hull floating on the sea surface, 3 is a television camera installed on the upper part of the hull, and 4 is the television camera 3. A mounting base 5 that supports the hull so as to be able to swing back and forth and left and right keeps the optical axis 6 of the television camera 3 in a constant direction, for example, the angle θ between the optical axis 6 and a vertical line 7. 8 is an image processing device that processes the video signal 9 sent from the television camera 3 to extract wave information [wave height a, wavelength b, wave direction C1, see Fig. 3]; A monitor displays the image information on a screen, and a printer prints it on recording paper.

The television camera 3 is an optical tube type image pickup tube (for example, a vidicon).
, or a solid-state imaging device (for example, a COD image sensor), or a night-vision television camera that uses infrared rays, especially when performing night observations.

The television camera installation stand 4 consists of a pedestal 13 fixed to the hull 2 and having a spherical top, and a pedestal 14 placed on the pedestal 13 and having a concave surface that engages with the spherical surface. An attitude control device 5 that applies the principle of a gyro swings the support base 14 back and forth and left and right via an arm (as indicated by arrows d and e).
), the above-mentioned θ is maintained constant even if the hull 2 is tilted. In addition, there are water gauges 15.1 on the port and starboard sides of the hull 2.
6 is provided, and this stuttering data is used to accurately estimate the distance f between the television camera 3 and the wave 1 to be observed, as will be described later.

Image processing LIT! The device 48 is an analog-to-digital converter 17 that A/D converts the video signal 9 sent out from the television camera 3, that is, the flow of charges accumulated in each photoelectric conversion element constituting an electronic image and sequentially taken out by scanning. (If the TV camera 3 is a solid-state FI image device, the video signal is digitally extracted at fixed time intervals by the transfer pulse controlled by the clock pulse, so an A/D converter is not necessary.) a gate circuit 18 for dividing and inputting columns at fixed time intervals synchronized with each horizontal scan during imaging; a discriminating circuit 19 for binarizing the input signal into a wave signal and a signal other than the wave signal;
A counting circuit 20 that measures the number of each signal converted to il, calculates the shape and dimensions of a stacked wave image 22 by connecting each measurement result to vertical scanning at the i-image time, and calculates the area of a half-wave wave image. Calculating and storing the center position (center of gravity) 24, and further calculating the wave direction C, that is, the motion vector, from the locus 25 along which the area center position 24 moves over time.
It consists of a storage device 27 and the like.

Although not mentioned above, the A/D conversion device 1 note It is a provision.

Further, in Fig. 1, 28 is a compass for determining the direction of the wave direction after calculation, 29 is a speedometer for correcting the motion vector indicating the wave direction, and 30 is the wind direction and wind speed that serve as a reference for the wave direction. 32 is an inclinometer for detecting the horizontal state of the hull; 33. Reference numeral 34 denotes an interface, and the inclinometer 32 may be omitted if water droplets are provided on both sides of the hull.

Next, the wave observation procedure using this device will be explained. There are two observation methods: one is to instantaneously m-image the waves to determine the wavelength and wave height, and the other is to point a TV camera in one direction for a certain period of time to capture images of the movement of waves over time, in addition to the wavelength and wave height. There are two methods for observing the direction, but the latter method will be explained first.

The observation procedure is to calculate the distance r from the television camera 3 to the wave 1 to be observed and determine the scale of the vertical and horizontal dimensions of the m-image screen relative to the actual object (step 1). Next, the shape of the wave on the bottom surface, The dimensions are measured electronically (step 2), and the dimensions on the screen are converted to actual dimensions using the scale (step 3).

The distance f from the television camera 3 to the wave 1 is found as the hypotenuse of a right triangle ABC whose apex angle is θ, and the vertical side A
The length 35 of C is determined by subtracting the average water drop 38 on the port and starboard sides from the height dimension 31 between the bottom 36 and the television camera 3. θ
Even if is constant, if the hull 2 tilts, the length of the vertical side will be 3
5 changes, read the difference between the hiccup needles 15 and 16 and correct the values of θ and 35. All the above arithmetic operations are automatically performed by the arithmetic unit @27.

After removing noise, the analog video signal 9 sent from the television camera 3 passes through the A/D converter 17 and becomes a dired signal (if the television camera 3 is a solid-state m-image device, A/D conversion is not necessary). ), then passes through the gate circuit 18 and enters the identification circuit 19 . Identification circuit 19
The signal 39 is divided into two groups, upper and lower, with a "threshold value" as a boundary, and converted into values. Since the wave image 22 is brighter than the inter-wave image portion 39, the wave image becomes 0 and the wave interval becomes 1, which enters the counting circuit 20.

The counting circuit 20 counts the number of zero and one signals every time a horizontal scan is performed and stores the measured value. Since the number of pixels arrayed in the horizontal and vertical directions on the imaging surface and the vertical and horizontal dimensions of each pixel are determined from the beginning, the length 40 of the horizontal section of the wave image 22 and the horizontal position within the screen are determined, and these The value of is memorized.

In this way, as the horizontal scan progresses sequentially from the top to the bottom of the wave image 122, the two-dimensional spread of the wave image 22 (shown by hatching in FIGS. 3 and 4) is numerically determined. . Then, the shape and dimensions of the wave image 22 obtained on the screen are enlarged according to the scale scale described above,
Find the shape and dimensions (wavelength a, wave height, etc.) of a real-scale wave.

To determine the wave direction C, the movement of waves is observed over time.

Specifically, it is convenient to observe the movement of a point representative of the wave shape, for example, the center of area (center of gravity) 24 (see FIG. 4) of a half-wavelength wave image. As mentioned above, the horizontal and vertical distribution of pixels corresponding to the wave image is sequentially measured and stored, so the area center position 24 is calculated by following this process, and the area center locus 25 is calculated.
Find the wave direction C from

The shape and movement of the waves thus determined are displayed as images in real time on the screen of the monitor 10, and the observed data are recorded on recording paper by the printer 11.

Next, a second wave observation method will be described.

This method instantaneously captures a wave image to determine the wavelength and wave direction, and the wave direction is estimated based on the wind direction and anemometer reading. The television camera is fixed to the hull, as there is no need to observe the movement of waves over time. You can take the image at any time, but it is convenient to choose a time when the hull is not tilted.
When the readings of the inclinometers 6 and 6 become almost equal, or when the reading of the inclinometer 32 on the hull becomes zero, a command between imaging can be issued to the television camera.

This method has a wide range of applications, as observation can be prepared simply by attaching a television camera to an existing ship equipped with a regular electronic computer.

Note that the present invention is not limited to the above-described embodiments; for example, the television camera may use any type of image pickup tube or image sensor, and the image processing device may use various known discrimination circuits, It goes without saying that various changes can be made without departing from the gist of the Ikemizu invention, such as a combination of length measuring circuits and the like.

[Effects of the Invention] As described above, the present invention exhibits the following excellent effects.

(1) Waves are imaged using an ML imaging device, and the wave images are electronically processed, so wave information can be automatically and accurately grasped.

0) As a result of item (1), it is possible to save labor during navigation and eliminate the dangers of conventional wave observation work during stormy weather.

(To) Wave observation can be conducted even at night by using night vision television cameras.

0 It is possible to perform high-precision wave observation that is practically satisfactory by simply attaching a television camera to an existing ship that is equipped with normal measuring equipment necessary for navigation and normal electronic computers for automation.

[Brief explanation of drawings]

1 to 4 show embodiments of the present invention, FIG. 1 is a block diagram of the device, FIG. 2 is an explanatory diagram of wave observation procedures, FIG. 3 is an explanatory diagram of electronic images, and FIG. The figure is an enlarged view of the wave image shown in FIG. 3. In the figure, 1 is a wave, 2 is a ship's body, 3 is a television camera, and 8 is an image processing device. Patent application: Japan Shipbuilding Research Association Patent application: Ishikawajima-Harima Heavy Industries Co., Ltd.

Claims (1)

[Scope of Claims] 1) An imaging device attached to a ship's hull facing the water surface, an image processing device that processes a video signal captured by the imaging device and extracts the shape and size of a wave image in the video, and the imaging device A wave observation device comprising: a sensor for estimating the distance from the device to waves to be observed. 2) The wave observation device according to claim 1, further comprising an attitude control device for always keeping the imaging device oriented in a fixed direction.