JPH06300839A - Underwater object position detector - Google Patents

Abstract

PURPOSE:To put a device into practical applications by laying out a plurality of ultrasonic probes while the mounting angle is inclined by a directional angle. CONSTITUTION:For example, three ultrasonic probes 3a, 3b, and 3c for dipping in water are mounted to a holder while the mounting angle is inclined by a directional angle under a water surface 1 where an object 2 in water exists and at the same time the ultrasonic probes 3a, 3b, and 3c are connected to a pulser receiver 5 outside the water surface 1 in parallel. By laying out three ultrasonic probes 3a, 3b, and 3c in this manner, either one of the ultrasonic probes :3a, 3b, and 3c detects the inclination of the object 2 in water by pitheta, thus measuring the distance with the object 2 in water. Therefore, by using the device, the range of distance in water for several m can be measured without any practical problems.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater object position detecting device applied to obstacle detection of an underwater robot and position control of a marine oil production facility.

[0002]

2. Description of the Related Art Conventionally, a fish finder or sonar has been used as a position detecting device for an underwater object.
It was developed to detect underwater objects at a distance of m to several hundreds of meters, and within a short distance of 10 m, the measurement accuracy deteriorates due to reflected waves and noise, and because it is for long distances, it propagates in the sea. Low frequency with low propagation attenuation 1
Since the oscillator of 0 kHz to several hundreds of kHz is adopted, there are drawbacks such as poor detection resolution of the detection target. On the other hand, as a position signal applied for detecting obstacles of underwater robots and position control of marine structures, it is necessary to be able to detect even thin objects within a distance of 10 m in the sea, and as an underwater object position detection device suitable for this purpose, a laser Although a range-type distance meter has been developed, it is very expensive and requires waterproof treatment, so it can be mounted on a submarine robot that is a large-scale device.
Miniaturization and weight reduction are also very important factors, and frequency f = 0.5
A device that uses an ultrasonic probe for immersion in the frequency of MHz to 2 MHz as a sonar is conceivable.

However, this device is as shown in the schematic view of FIG. 3, in which an ultrasonic probe 3 is arranged below the water surface 1, an ultrasonic wave is emitted from the ultrasonic probe 3 and hits an underwater object 2 to be reflected. The ultrasonic wave 3 is received by the ultrasonic probe 3, converted into an electric signal by the pulsar receiver 5 outside the water surface 1 connected by the connection cable 6, and the distance between the ultrasonic probe 3 and the underwater object 2 is a reflected wave. It is measured from the arrival time of. This device can detect an underwater object with a pipe diameter of several mm at a distance of several meters. However, due to the high frequency and the narrow spread of the ultrasonic beam, the underwater object 2
When the relative squareness of the ultrasonic probe 3 becomes worse, the reflected wave cannot be received at the position shown in FIG. 3B, which is practically inconvenient.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above circumstances, and the underwater distance is accurate even if the relative squareness between the underwater object and the ultrasonic probe is slightly worse. It is an object of the present invention to provide a device for detecting the position of an underwater object that can be measured well and has no practical problems.

[0005]

To this end, according to the present invention, a plurality of ultrasonic transducers for immersion are arranged below the surface of the water in which an underwater object is present, with their mounting angles inclined by the directivity angle. One ultrasonic probe is connected in parallel to one pulsar receiver outside the water surface.

[0006]

In the underwater object position detecting apparatus of the present invention, a plurality of ultrasonic probes are tilted by the directivity angle and a plurality of them are arranged so that the ultrasonic probes are tilted corresponding to the mounting angle of each ultrasonic probe. Underwater objects can be detected.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of the underwater object position detecting device of the present invention will be described. FIG. 1 is a schematic view of the entire device, and FIG. 2 is a front view of the ultrasonic probe. In the figure above, under the water surface 1 where the underwater object 2 exists, three ultrasonic probes 3a, 3b, 3c for immersion are attached to the holder 4 with the attachment angle inclined by the directivity angle. At the same time, the ultrasonic probes 3a, 3b, 3c are connected in parallel with the pulsar receiver 5 outside the water surface 1 by a connection cable 6. Thus, by disposing the three ultrasonic probes 3a, 3b, 3c in this way, even if the underwater object 2 is inclined by ± θ, the ultrasonic probe 3
Any of a, 3b, and 3c will be detected, and the distance to the underwater object 2 can be measured. Therefore, by using this device, it is possible to measure a range of a distance of several meters underwater without causing any problems in practical use.

[0008]

In summary, according to the present invention, a plurality of ultrasonic transducers for water immersion are arranged below the surface of the water in which an underwater object is present, with the mounting angle inclined by the directivity angle. By connecting the ultrasonic probe in parallel to one pulsar receiver outside the water surface, the underwater distance can be accurately measured even if the relative squareness between the underwater object and the ultrasonic probe is slightly worse, and it is practical Since we can obtain an underwater object position detection device that does not hinder
The present invention is extremely useful in industry.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of an underwater object position detecting device of the present invention.

FIG. 2 is a front view of the ultrasonic probe.

FIG. 3 is a schematic view of a conventional underwater object position detection device.

[Explanation of symbols]

 1 Water surface 2 Underwater objects 3a, 3b, 3c Ultrasonic probe 4 Holder 5 Pulser receiver 6 Connection cable

Claims (1)

[Claims] 1. A plurality of ultrasonic probes for immersion are arranged below the surface of the water in which an underwater object is present, with their mounting angles inclined by a directivity angle, and the plurality of ultrasonic probes are located outside the surface of the water. An underwater object position detection device characterized in that it is connected in parallel to one pulsar receiver.