JPS6220507B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an echo detection device using waves, and more particularly to a precision echo sounder having a distance counting circuit.

Conventionally, when an echo detection device includes a distance counting circuit that outputs the distance to a target as a digital electrical signal, it accurately selects only the target, automatically tracks it, and outputs the correct digital value. It was a very difficult technology to convert. Particularly in the case of a depth sounder, there are unnecessary echoes from floating objects and schools of fish, and navigation noise between the target and the seabed, and the seabed that was being tracked may be drawn in by other unnecessary signals. There were cases where the wrong value was output.

On the other hand, in order to perform precise sounding, the beam of the transducer must be made as narrow as possible so that only the area directly below can be received. In a transducer using a planar array of transducer elements with the same element and same drive,
If the directivity is set to less than a few degrees, the wave surface for transmission and reception becomes large, and there is a problem that the beam cannot be made narrower than the size of the wave surface for transmission and reception at short distances. For this reason, a method has been proposed in which the transmitting and receiving elements are not driven in the same way in a short distance range, but are focused by changing their phases.

This focusing is just like focusing a camera, and it is necessary to focus at each desired distance. Generally, in an echo detector, after transmission, echo signals are received one after another in proportion to the time. Therefore, this focusing can be automatically controlled so that the position moves away with time immediately after transmission, and this method is in practical use. In this case, each echo point is optimally focused, so it is effective when the purpose is to detect all targets at different distances. In the case where the purpose was to detect and track only the seabed, it had no effect on improving the probability of seabed detection.

An object of the present invention is to solve the problems of the conventional devices described above, and to reduce the probability of detecting echoes from a target other than the target when tracking echoes from a target once detected. An object of the present invention is to provide an echo detection device capable of outputting improved and highly reliable digitized distance information.

According to the present invention, a transducer group including a plurality of transducers, a focusing control circuit that focuses a beam at a certain distance, and a focusing control circuit that receives a received signal from the transducer group and directs the beam to a target. and a distance counting circuit that outputs a signal corresponding to the distance, and controlling the focusing control circuit so that the beam is focused on the target by the output of the distance counting circuit. .

Next, embodiments of the present invention will be described with reference to the drawings.

Referring to the figure, the embodiment of the precision acoustic measuring device includes a distance counting circuit 2 connected to the output of a transceiver 1, a focusing control circuit 3 controlled by this output value,
This focusing control circuit 3 is configured to be inserted between the transceiver 1 and the transceiver element group 4.

The transceiver 1 sends a transmission pulse modulated wave to the focusing control circuit 3. In the focusing control circuit 3, the previous measurement was carried out,
In response to the sounding output value from the distance counting circuit 2 in which the value is held, the time is set for each element of the transducer element group 4 so that the input transmitted pulse modulated wave is focused exactly at the depth of the sounding output value. The axes are adjusted and outputted to the transducer element group 4, respectively.

The transmitted sound waves propagate through the ocean, becoming focused near the target ocean floor and becoming more powerful. The reflected wave is received by the transducer element group 4, converted into an electrical signal, and then applied to the focusing control circuit 3. At this time, the focusing control circuit is adjusted to focus on the target seabed, so only the seabed pressure waves are intensified because their time axes match, and signals from other distances are not amplified because their time axes do not match. The focusing control circuit 3 can use, for example, a variable delay circuit network.

As described above, the received output with only the seabed reflected waves enhanced is added to the receiving circuit of the transceiver 1, amplified, and then input to the distance counting circuit 2, where the seabed reflected waves are selected and received from transmission. The sounding value is determined from the elapsed time and is output from the terminal 5 to an external device. The distance counting circuit 2 includes a seabed reflected wave discrimination circuit, and various types of circuits that are normally applied to improve reliability by storing the previous sounding value and opening the gate by a certain width before and after that value to select only the seabed. The following method can be adopted.

The above explanation has been given for an example in which the transmitting and receiving waves are both focused, but even if only one of the transmitting and receiving waves is focused,
It is clear that considerable effects can be expected.

That is, in the echo detection device according to the present invention, the output signal from the receiver is applied to a distance counting circuit to convert the distance to the target into an electrical signal, and this output value is applied to the focus control circuit to calculate the distance to the target. It outputs a control signal to each transmitting/receiving element to focus exactly, and controls each transmitting/receiving element group connected to this control circuit to focus on the target point. Since the echo signals are out of focus, the signals do not overlap and are blurred, and at the same time, the signal strength can be reduced compared to when the signals are focused without being added to the maximum, and the target signal is It becomes possible to significantly increase the difference in the strength of unnecessary echo signals. In addition, when the target position changes, focus control is automatically performed in the order described above, so that the device always operates in an optimal state and outputs a highly reliable target distance as a digital electrical signal. be able to.

As explained above, the present invention automatically controls the transducer beam to focus on the target being measured based on the output value of the distance counting circuit, thereby adjusting the level of the reflected wave from the target point. Since the reflected waves from other distances will be out of focus, the signal will be dispersed on the time axis and the rise will be gradual, and at the same time, the degree to which the combined signal will be enhanced will be suppressed. This has the effect of increasing the probability of comprehensive target selection and significantly improving the reliability of the output of the distance counting circuit.

In addition, by focusing the waves during transmission, the irradiation range of the transmitted wave force at the target point can be narrowed.
This has the effect of significantly reducing distance measurement errors due to the inclination and unevenness of the target reflecting surface, and improving the accuracy of distance measurement.

[Brief explanation of the drawing]

The figure is a block diagram showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Transmitter/receiver, 2... Distance counting circuit, 3... Focusing control circuit, 4... Transducer/receiver element group, 5... Distance counting output terminal.

Claims (1)

[Claims] 1. A transducer group in which a plurality of transducers are arranged, a focusing control circuit that focuses the beam at a certain distance, and a signal that receives the received signal from the transducer group and corresponds to the distance to the target. and a distance counting circuit that outputs a distance counting circuit, and controlling the focusing control circuit so that the beam is focused on the target by the output of the distance counting circuit.