JPS6335425Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sonar device that detects underwater objects using ultrasonic waves.

It is well known that when displaying information such as schools of fish detected by sonar, the so-called PPI display is used to display the distance from the own ship to the object and the direction of the object relative to the own ship in a plan view on the image screen of the cathode ray tube. That's right.

In addition to this basic PPI display, in order to grasp even more precise information, when combining cross-sectional display, the direction of the ultrasonic beam is determined appropriately and the object is tilted at a certain angle θ. The results are displayed in PPI in one section of the cathode ray tube screen, and the remaining sections are displayed at θ ₁ with respect to the horizontal direction.
The direction of the ultrasonic beam is sequentially changed from θ _o to 60°, for example, every 10°, and the results of detection in each direction, that is, the information cut into a cross section, are displayed.

Fig. 1 is an explanatory diagram when PPI display and cross-section display are both shown. 1 is the image screen of a rectangular raster scanning cathode ray tube, A is the PPI display area, B is the cross-section display area, 2 is the own ship position, 3 is the seabed, 4 is a school of fish,
5 is a reference oscillation line, 6 is the seabed, and 7 is a school of fish.

When using a single transducer to obtain such images, the data necessary for PPI display and cross-sectional display must be separated, so it is necessary to transmit waves alternately. However, in cross-sectional display, detection is performed by sequentially changing the angle of depression of the transducer, which takes time, which is a negative factor from the perspective of obtaining images with a large amount of information.

Also, if the frequency is lowered to extend the search distance, the resolution of the range to be cross-sectionally displayed will be lower due to the short distance, which is not desirable for conducting precise investigations. The absorption attenuation becomes large and the search distance cannot be extended.

In general, the PPI display is used to show the results of long-distance searches, and the cross-sectional display is used to learn the swimming and distribution states of schools of fish at short distances.In addition to increasing the overall information density, low frequency ,
It is more effective to use high frequencies for cross-sectional display.

In view of these points, the present invention integrates two high- and low-frequency transducers in a dome that can be raised and lowered, the PPI display transducer for low frequency, and the cross-section display transducer for high frequency. The two transducers, high and low, are driven simultaneously to ensure efficient and effective searching.

FIG. 2 shows the transducer of the embodiment, and FIG. 3 shows an outline of the block diagram of the operating system mainly consisting of the main parts.

In FIG. 2, reference numeral 8 denotes a dome, which is configured to descend and protrude below the bottom of the ship when in use, and to be pulled up into the ship when not in use.

Reference numeral 9 indicates a low-frequency transducer, and numeral 10 indicates a high-frequency transducer. Both are formed in a cylindrical shape, and a group of vibrating elements made of, for example, barium titanate are arranged over the entire outer surface of the transducer, and the ultrasonic beam is given an angle of depression. In case of tilting, the plurality of rows of vibrating element groups are appropriately combined and operated by electronic control so as to tilt at a predetermined angle.

In FIG. 3, 9 and 10 are the transducers, 11
is a keying circuit, 12 is a low frequency transmitter/receiver, 1
3 is a depression angle controller, 14 is a high frequency transmitter/receiver, 15
is a television type (raster scan) cathode ray tube display, and this display includes a storage section and a sweep control section for performing air traffic control consisting of a commonly implemented configuration for PPI display and cross-sectional display. ing.

A pulse with a period T ₁ generated from the keying circuit 11 is applied to the low frequency transducer 12, and when the low frequency transducer 9 is driven by the output, the pulse is applied to the low frequency transducer 9 in a preset direction, for example, at an angle of 10 degrees. Ultrasonic waves of high frequency are transmitted. When the reflected waves from a school of fish return, the signal amplified along the path from the transducer 9 to the low frequency transceiver is displayed in the PPI display area of the cathode ray tube display 15 as shown in FIG.

Next, when using a high frequency to search a relatively short distance, rather than displaying PPI at a low frequency, the period T ₂ from the keying circuit 11 (this period is shorter than the period T ₁ in the case of a low frequency) The depression angle controller 13 is driven by the pulse, and the pointing direction of the high-frequency transducer is controlled to be tilted by a predetermined angle, for example, 10 degrees. Then, the pulse of the keying circuit 11 is applied to the high frequency transceiver 14, and the output of the pulse is applied to the high frequency transceiver 1.
The reflected signal from the high-frequency ultrasonic wave sent out when the 0 is driven passes through the high-frequency transducer 10 → the high-frequency transceiver 14, and is displayed as a cross-sectional image in the cross-sectional display area of the cathode ray tube display 15 as shown in FIG. .
Furthermore, when the high-frequency transducer 10 receives waves, if the receiving direction mark is superimposed and displayed on the PPI display image of the cathode ray tube display 15 using the direction switching signal (FIG. 1, 11, 11'), the cross-sectional area You can tell at a glance which direction the image is from.

In this case, it goes without saying that the state of the cross section on the left side of own ship position 2 in the PPI display image is displayed on the left half of the cross section display area, and the state of the cross section on the right side is also displayed on the right half. And since the frequencies of the PPI and the transducer used to display the cross section are different, even if they transmit and receive at the same time, there will be no interference with each other, and the images of both will be clear.

As described above, the present invention is equipped with transducers for high and low frequencies in the dome, drives these transducers simultaneously, and, unlike conventional methods, transmits ultrasonic waves frequently to obtain dense images. , PPI and cross-sectional images can be drawn effectively and appropriately, making it extremely effective for exploration in fisheries.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of PPI display and cross-sectional display. FIG. 2 shows a transducer according to the embodiment. Figure 3 is a block tube diagram of the operating system. 1... CRT image screen, 2... Own ship position, 3
... seabed, 4 ... school of fish, 5 ... oscillation line, 6 ... seabed, 7 ... school of fish, 8 ... dome, 9 ... low frequency transducer, 10 ... high frequency transducer, 11 ... Keying circuit, 12...Low frequency transmitter/receiver, 13...
Depression angle controller, 14... High frequency transmitter/receiver, 15...
CRT display.

Claims (1)

[Scope of utility model registration request] A low-frequency transducer transmits low-frequency ultrasonic waves in the horizontal direction at a predetermined period T ₁ , and a depression angle is sequentially applied at arbitrary angles to the horizontal direction at a period T ₂ different from the period T ₁ . Both a high-frequency transducer and a high-frequency transducer that transmit high-frequency ultrasonic waves in an inclined direction are assembled and housed in the same dome, and low-frequency information is transmitted as a PPI image to a fixed area on the image plane of the cathode ray tube display. What is claimed is: 1. A sonar device using a raster scanning cathode ray tube, characterized in that the high frequency information is displayed in one area and high frequency information is displayed in the remaining area as a cross-sectional image.