JPS63204181A - Automatic sensitivity adjustment method for fish finders - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an automatic sensitivity adjustment method for a fish finder that automatically adjusts the sensitivity of a fish finder that can be installed on a vessel such as a fishing boat or a leisure boat. It is.

[Prior art]

A fish finder usually emits ultrasonic waves toward the seabed from an ultrasonic transducer, and a receiver receives the ultrasonic waves reflected from objects such as the seabed and schools of fish via the ultrasonic transducer. death,
The signal is amplified by an amplifier, then subjected to predetermined processing by a signal control processing means, and outputted to a display means such as a recorder or CRT for display.

In a fish finder with the above configuration, when identifying an object such as the seabed or a school of fish from the image displayed on the display means, the sensitivity is usually adjusted so that the object such as the sea bed or school of fish is properly displayed on the display means. There is a need to. Conventionally, such sensitivity adjustment is normally performed by an operator manually adjusting the amplification factor of the amplifier, etc.

[Problem that the invention seeks to solve]

However, as mentioned above, adjusting the sensitivity only manually by the operator is difficult for operators who are involved in specialized fields, such as those involved in fishing, to be able to always maintain a constant sensitivity and to control the reaction. Although it is possible to distinguish sensitively, there is a problem in that it is difficult for amateurs who are not involved in such specialized fields to adjust the sensitivity. Particularly in recent years, so-called fish finders installed on leisure boats aimed at the general public have appeared, and there has been a demand for fish finders that can be easily adjusted for sensitivity. There were no fish finders with means of adjustment.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide an automatic sensitivity adjustment method for a fish finder that eliminates the above problems, has a simple configuration, and can automatically adjust reception sensitivity.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention emits ultrasonic waves from an ultrasonic transducer, receives them at a receiver via the ultrasonic transducer, amplifies them with an amplifier, and then uses a signal control processing means to produce a predetermined amount of ultrasonic waves. A first comparator outputs an output when the signal level received by the receiver exceeds a predetermined first set level value; A second comparator that outputs an output when a predetermined level value below the first set level value is exceeded, and an amplification factor control means for controlling an amplification factor of the amplifier, and the signal processing control means is provided with If the signal level received by the receiver is below the first and second set level values, the amplification factor of the amplifier is increased via the amplification factor control means, and the signal level received by the receiver is set to the first and second set level values. If the signal level received by the receiver is between the first and second set level values, the fish finder is adjusted so that the amplification factor of the amplifier is maintained at the current level. Configured automatic sensitivity adjustment method.

[Effect]

By configuring the automatic sensitivity adjustment method of the fish finder as described above, by selecting the first setting level value and the second setting level value to predetermined values, it is possible to adjust the signal level received by the receiver. It becomes possible to automatically suppress the output level of the amplifier between the first set level and the second set level regardless of the output level.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing the configuration of a fish finder employing an automatic sensitivity adjustment method according to the present invention.

In the figure, 11 is an ultrasonic transducer that emits and receives ultrasonic waves, 12 is an oscillator that sends an oscillation signal to the ultrasonic transducer 1, and 13 is an ultrasonic transducer that transmits an oscillation signal to the ultrasonic transducer 11. 14 is the receiver 13 for receiving the ultrasonic signal;
15 is an A/D converter that converts the analog signal from the amplifier 14 into a digital signal; 16 is a bencoder or CRT display that receives and displays the signal from the A/D converter 15; 17 is a first comparator that outputs an output signal G8 if the output of the amplifier 14 is above a predetermined first setting level; 18 is a first comparator that outputs an output signal G8 when the output of the amplifier 14 is at a predetermined second level a second comparator that outputs an output signal G if it is above a set level; 19 a memory that stores the output signal G of the first comparator 17; and 2o an output signal of the second comparator 18. Memory device that stores GL, 2
2 is an amplification factor control circuit for controlling the amplification factor of the amplifier 14, and 21 is a control circuit (CPU) for controlling the above-mentioned parts constituting the fish finder.

The first comparator 17 receives the reference voltage to be set at the first setting level L)l1, and the second comparator 18? Here, a reference voltage VL for setting the second setting level LL is input.

In the fish finder with the above configuration, an example of the level of ultrasonic waves emitted from the ultrasonic transducer 11, reflected by objects such as schools of fish or the seabed, and reaching the ultrasonic transducer 11 again is shown in Figure 2. show. In the figure, A indicates an ultrasonic wave emitted from the ultrasonic transducer 11, B and C indicate an ultrasonic wave reflected from an object, etc., and D indicates an ultrasonic wave reflected from the ocean floor. Also,
The vertical axis shows level (dB) and the horizontal axis shows time. Also,
LH indicates the first setting level of the first comparator 17, and LL indicates the second setting level of the second comparator 18. As shown in the figure, the first set level LH is set higher than the second set level by a predetermined value.

The ultrasonic wave A emitted from the ultrasonic transducer 11 toward the seabed is reflected by the object and the seabed, and after a predetermined period of time, the ultrasonic transducer 11 receives a reflected wave B.

Received as C and D. Received reflected wave B.

C and D are converted into electrical signals by the receiver 13, amplified by the amplifier 14, converted into digital signals by the A/D converter 15, and displayed on the display 16 in relation to the arrival time, that is, the water depth. .

Here, as shown by the dotted line in FIG. The output signals G and G of the second comparator 18 each become "1", which is stored in the memory 19 and the memory 20. Further, as shown by the solid line, when the level of the reflected wave reflected by the seabed is between the first setting level L and the second setting level Lt, the output signal GH of the first comparator 17 is "0", the output signal GL of the second comparator 18 becomes r 1 , and the memory 19 and the memory 20 respectively
is memorized. In addition, as shown by the dashed line, the level of the reflected waves reflected by the seabed is the first set level Ll (
and if it is below the second set level LL, the output signals of the first comparator 17 and the second comparator 18 G) I and G
Each L becomes "OJ" and is stored in the memory 19 and the memory 20, respectively.

The control circuit 21 reads the stored values of the memory 19 and the memory 20, and when the output signals G and GL are both 11'', that is, the level of the reflected wave is equal to the first value of the first comparator 17.
If the set level L is exceeded, the amplification factor control circuit 22
The amplification factor of the amplifier 14 is lowered through. Further, when either of the output signals GM and G is "0", that is, the level of the reflected wave is at the second set level LL of the second comparator 18.
In the following cases, the amplifier 14
Increase the amplification factor. In addition, when the output signal G is "O" and the output signal G is "11", that is, the level of the reflected wave is the first
If the current level is between the set level LH and the second set level LL, the amplification factor of the amplifier 14 is maintained at the current state.

FIG. 3 is a flowchart showing the flow of the amplification factor control process of the control circuit 21. First, in step 101, it is determined whether the output signal GM of the first comparator 17 is r1.
), if not '1', then it is determined whether the output signal of the second comparator 18 is '11' or not (step 102), '1'.
．． If so, the current amplification factor of the amplifier 14 is maintained.

In step 101, if the output signal G is "1.", set 1 to the counter CNTI (step 103), and then judge whether the count value of the counter CNT is N or not. (Step 104), that is, the output signal G
Determine whether “I(11 of 11”) continues N times, and if the count value is N
If so, the amplification factor of the amplifier 14 is decreased by one step (step 105), and then the counter CNT is cleared (step 106). This process is to prevent the amplification factor of the amplifier 14 from changing when the output signal G□ accidentally becomes "1" due to the influence of noise or the like.

In step 102, if the output signal GL is not "1", 1 is added to the counter CNT (step 10).
7), then 1 is added to the counter CNT (step 108). Next, it is determined whether the count value of the counter CNT is N or not (step 109), and if it is N, then it is determined whether the count value of the counter CNT2 is each M (step 110), and if not M The amplification factor of the amplifier 14 is increased by one step (step 111), and then the counter CNT is cleared (step 112). This process is performed when the output signals GH and G1 accidentally become r□ for some reason.
This is a process to prevent the amplification factor from changing.

In step 110, if the count value of the counter CNT2 is M, that is, rO of the output signals GH and GL.
If this continues M times, the depth of the ocean floor is large and the reflected waves from the ocean floor may be too small. Therefore, set the amplification factor of the amplifier 14 to an arbitrary value for ocean floor exploration (step 1).
14).

As explained above, according to the above embodiment, the control circuit 21
is, the output of the amplifier 14 is the first setting level LH of the first comparator 17 and the second setting level LH of the second comparator 18.
Since the amplification factor of the amplifier 14 is controlled via the amplification factor control circuit 22 so that the amplification factor is within t, by selecting the first set level value and the second set level value to predetermined values,
The sensitivity of the fishfinder can be automatically adjusted regardless of the signal level received by the receiver.

In addition, in order to automatically adjust the sensitivity as described above, a conventional fish finder is equipped with a first comparator 17 and a second comparator.
This can be realized by simply adding some component circuits such as the comparator 18 and the amplification factor control circuit 22.

〔Effect of the invention〕

As explained above, according to the present invention, the control processing means:
If the signal level received by the receiver is below the first and second set level values, increase the amplification factor of the amplifier, and if it is above the first and second set level values, reduce the amplification factor of the amplifier, Furthermore, since the amplifier amplification factor is automatically controlled to maintain the current amplifier amplification factor within the first and second set level values, there is no need to manually adjust the sensitivity of the fish finder, and the fish school Even an amateur operator who is not familiar with the operation of a fish finder can obtain an excellent effect of operating the fish finder.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of a fish finder that employs the automatic sensitivity adjustment method according to the present invention, and Fig. 2 shows the ultrasonic waves emitted from the ultrasonic transducer and the ultrasonic waves reflected by objects and the seabed. FIG. 3, which is a diagram showing an example of the level of sound waves, is a flowchart showing the flow of the amplification factor control process of the control circuit. In the figure, 11... Ultrasonic transducer, 12... Oscillator, 13... Receiver, 14... Amplifier, 15...
...A/D converter, 16...Display device, 17...
・First comparator, 18...Second comparator, 19...
... Memory device, 20 ... Memory device, 21 ... Control circuit, 22 ... Amplification factor control circuit.

Claims (1)

[Claims] Ultrasonic waves are emitted from an ultrasonic transducer, the reflected ultrasonic waves are received by a receiver via the ultrasonic transducer, amplified by an amplifier, and then subjected to predetermined processing by a signal processing control means to be displayed on a display means. a first comparator that outputs an output when the signal level received by the receiver exceeds a predetermined first set level value; a second comparator that outputs an output when the following predetermined second set level value is exceeded; and amplification factor control means for controlling the amplification factor of the amplifier; The signal level is the first and second signal level.
If the level of the signal received by the receiver is below the set level value, the signal processing control means increases the amplification factor of the amplifier via the amplification factor control means. If the signal level received by the receiver is within the first and second set level values, the amplification factor of the amplifier is maintained at the current level. Automatic sensitivity adjustment method.