JP2002098761A - Fish finder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly set an optimum reception gain for a receiver in response to change of a depth sounding range, abrupt change of a submarine topography, change of transmitting and receiving frequencies and/or the like. SOLUTION: This fish finder is provided with a sounding range setting means, a received gain storing means for storing plural received gains in every received frequency, and a reception gain setting means for setting the received gain according to the sounding range, as the first invention. A received frequency reading means is also provided to read the received frequency received in the receiver, as the second invention.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reception gain setting for a receiver of a fish finder.

[0002]

2. Description of the Related Art In a fish finder, the latest information in the depth direction is obtained as a reflection signal of a detection pulse every time a detection pulse is transmitted, and the reflection signal is amplified and detected by a receiver.
By performing the / D conversion, it is stored in the memory as one detection signal. The obtained one detection signal is displayed by scrolling the detection signals obtained earlier. As a result, the detection signal of the past time can be displayed, and information on the underwater fish school and the seabed is displayed as the detection image.

[0003] The detected image has a display color corresponding to the detected signal level (normally, red, orange,
Yellow, green, light green, white, light blue, and blue). The fish finder differs in the detection signal level of the fish school and the sea bottom in the environment in which it is used. The user determines the reception gain of the receiver (hereinafter, the reception gain is also referred to as sensitivity) according to the environment.

When the receiving gain is set to be large, the amplitude of the received waveform of the receiver becomes large, and the detected image has a large seabed display A1 as shown in FIG. 6, and a weakly reactive object such as plankton in the sea is also displayed on the plankton display A3. As a result, the level of the detection signal is displayed in a strong display color. Also, when the reception gain is set to be small, the reception waveform amplitude of the receiver becomes small, and the detected image has a thin seabed display B1 as shown in FIG. 7 and a weakly reactive object such as plankton in the sea has a plankton display B3 as shown in FIG. The level of the detection signal, such as disappearing, is displayed in a weak display color. On the contrary,
In the detection image set to an appropriate reception gain as shown in FIG. 8, the seabed display C1 is displayed with an appropriate thickness, and the fish school display C2, the plankton display C3, and the like are reliably visible without disappearing.

FIG. 1 is a block diagram of a conventional fish finder using a low frequency and a high frequency, and FIG.
3 is a detailed diagram of the transmission / reception unit 2. FIG. FIG. 3 is an operation panel configuration diagram. The configuration shown in each figure is
The present invention has the same configuration. As will be described later, the CPU 110 reads the content of the screen changeover switch 44 and determines whether to transmit or receive a low frequency or a high frequency. Transmission / reception unit 2 in response to a transmission command from CPU 110
A transmission signal is transmitted from the internal transmitter 21 to the transmitter / receiver 5 through the switching unit 20, and an ultrasonic signal is emitted into the sea. The reflected signal from the sea is converted into an electric signal by the transmitter / receiver 5 and passed through the switching unit 20 inside the transmission / reception unit 2 to the receiver 2.
2 is input. The receiver 22 amplifies and detects the reflected signal based on the reception gain set by the CPU 110 through the reading control unit 23, and outputs the amplified signal as a detection signal to the A / D conversion unit 10.
Output to 1.

The detection signal converted to a digital signal by the A / D converter 101 is divided into two. Here, one of the divided detection signals is input to the detection image memory 102,
Under the control of the PU 110, the L
It is displayed on the CD display 3. The other divided detection signal is input to the seafloor detection signal detection unit 201. The sea bottom detection signal detection unit 201 detects a sea bottom detection signal for each detection signal, and outputs a sea bottom detection detection signal to the CPU 110 when the sea bottom detection signal is detected.

The operation panel unit 4 includes a knob as shown in FIG.
Switches are arranged. The configuration diagram of the operation panel
The present invention has the same configuration. Each knob,
The state of the switch is input to the CPU 110 through the operation panel reading control unit 107. The CPU 110 controls the display mode, sounding range, transmission command, and the like according to the state of each knob and switch read through the operation panel reading control unit 107.

Reference numerals 42a and 42b denote sensitivity knobs for manually setting the high-frequency and low-frequency sensitivities, respectively. The knobs are rotated to set the reception gain (sensitivity) of the receiver to an optimum sensitivity. This sensitivity is set by operating the operation panel reading control unit 107 to determine the rotation position (sensitivity) of the knob.
This is performed by setting the sensitivity read by the U110 and further by the CPU 110 to the receiver 22 of the transmission / reception unit 2.

The above-described manual setting of the sensitivity is performed by setting the receiver 22 of the transmitting / receiving unit 2 such that the sensitivity is increased by rotating the sensitivity knobs 42a and 42b clockwise and is reduced by rotating the sensitivity knobs 42a and 42b counterclockwise. Done. As a result, the receiver can be set to the optimum sensitivity. The screen switch 44 is a switch for switching the transmission / reception frequency and selecting the display screen. Depending on the selected function, transmission / reception of only high frequency or low frequency is performed, or high / low frequency is alternately transmitted / received. I do.

Reference numeral 40 in FIG. 3 is a switch for selecting automatic sensitivity setting. Each time the switch 40 is pressed, automatic sensitivity setting and manual sensitivity setting are alternately selected. In the automatic sensitivity setting, regardless of the transmission / reception frequency, the sensitivity of the receiver 22 is set to be gradually increased from the lowest sensitivity for each transmission, and the sensitivity of the receiver 22 is set to be increased until the sea bottom can be detected. In the same manner as in the prior art, the sensitivity of the receiver 22 is determined in advance for each sounding range to be measured irrespective of the transmission / reception frequency, and the determined sensitivity is stored in the ROM 109a. It is read from the operation panel section 4 and the ROM 109a
There is a second conventional technique for reading out the corresponding determined sensitivity from the above and setting the sensitivity of the receiver 22.

In the first prior art, when the switch 40 is depressed and the automatic sensitivity is selected, the CPU 110 starts the processing of the flowchart of FIG. In response to a transmission command from the CPU 110, a transmission signal is transmitted from the transmitter 21 to the transducer 5 through the switching unit 20, and an ultrasonic signal is emitted into the sea. The reflected signal from the sea is converted into an electric signal by the transducer 5 and input to the receiver 22 through the switching unit 20. At this time, the reception gain (sensitivity) of the receiver 22 is determined in S91.
To the lowest state. The reception gain (sensitivity) of the receiver 22 is sequentially increased at every constant sensitivity until the sea bottom detection signal is detected in S92 and S93 each time transmission is performed next time. When the seafloor detection signal is detected from the detection signal by the seafloor detection signal detection unit 201, a predetermined reception gain increase setting is performed on the receiver 22 so as to more stably detect the seafloor detection signal in S94. Next, in S95, the depth at which the seafloor detection signal is detected is determined. By adding and subtracting a predetermined depth to and from the depth at which the seafloor detection signal is detected in S96, a lower limit and an upper limit depth range using the reception gain (sensitivity) set in S94 are determined. Then, for each transmission, in S97, it is determined whether or not the depth of the detected seabed detection signal is within the determined depth range. If the depth of the seafloor detection signal falls outside the determined lower and upper limit depth ranges, the process returns to S91. If the seafloor detection signal is within the determined lower limit and upper limit depth ranges, the measurement is continued with the sensitivity set for the receiver 22.

In the second prior art, when the switch 40 is depressed and the automatic sensitivity setting is selected, the sounding range set by the sounding range knob 43 is read from the operation panel reading control unit 10.
7, and is read into the CPU 110. As a result, the setting sensitivity of the corresponding sounding range stored in the ROM 109a is read in advance to set the sensitivity of the receiver 22. As described above, a transmission signal is transmitted from the transmitter 21 to the transmitter / receiver 5 in response to a transmission command from the CPU 110, and an ultrasonic signal is emitted into the sea. The reflected signal from the sea is converted into an electric signal by the transducer 5 and input to the receiver 22 by the switching unit 20. At this time, the receiving gain (sensitivity) of the receiver 22 is set by setting the corresponding sensitivity stored in the ROM 109a to the receiver 22 from the sounding range set by the sounding range knob 43.

[0013]

As described above, ultrasonic waves emitted into the sea are reflected by the sea floor, schools of fish, and the like, and are received by the transducer as reflected waves. Here, the attenuation characteristics of the ultrasonic wave reflected by the sea floor and the school of fish in the sea are generally expressed by the following equation: the degree of attenuation to the bottom of the sea is Equation (1), and the attenuation of the object is Equation (2). FIG. 10 shows an ultrasonic frequency of 50 kHz.
, Wherein the bold line represents the attenuation to the seabed, and the thin line represents the attenuation of the object. FIG. 11 shows attenuation characteristics at an ultrasonic frequency of 200 kHz. Here, the thick line portion and the thin line portion are shown in FIG.
Represents the same degree of attenuation. Comparing FIG. 10 with FIG. 11, it can be seen that the attenuation characteristics of each frequency in the sea are lower at lower frequencies and are less attenuated. This means that when the frequency of the ultrasonic waves is different, the receiver 22 can receive the same sounding range.
Means that the reception gain setting of the receiver 22 must be changed according to each frequency.

In the first prior art, as described above, the operation of sequentially increasing the reception gain setting of the receiver 22 is performed until the seafloor detection signal is detected by the seafloor detection signal detection unit 201 from the detection signal. For this reason, the receiver 22 sets the reception gain irrespective of the ultrasonic frequency and detects the seafloor detection signal. According to the first prior art, there is no problem when the seafloor detection signal can be detected stably, but when the seafloor detection signal is not detected due to a change in the sounding range, a sudden change in the seafloor topography, the receiver 22 becomes , Reception gain (sensitivity)
Is set to the lowest state, and the reception gain is set again until the seafloor detection signal is detected again. For this reason, transmission must be performed several times before stable reflected waves can be received, and there is a problem that it takes a long time to receive stable seabed detection signals.

On the other hand, in the second prior art, RO
The setting sensitivity of the corresponding sounding range held in M109a is read and sensitivity setting is performed on the receiver 22. Thus, even if the sounding range is changed, the reception gain setting of the receiver 22 has a predetermined sensitivity before receiving the reflected wave. For this reason, it does not take much time for stable reception. However, when the frequency of the ultrasonic waves to be received is different, in order to make the output from the receiver 22 the same even in the same sounding range as described above, the reception gain setting of the receiver 22 is set to each of the ultrasonic waves. Must change depending on frequency. In the second prior art, ROM
Since there is only one setting sensitivity of the corresponding sounding range held in the receiver 109a, the receiving device
There is a problem that the reflected signals output from the second and the second are not the same. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and quickly set an optimum receiving gain of a receiver in response to a change in sounding range, a sudden change in the seafloor topography, and / or a change in transmission / reception frequency. It is an object of the present invention to provide a fish finder capable of detecting fish.

[0016]

According to the first aspect of the present invention, a sounding range setting means, a receiving gain storing means for storing a plurality of receiving gains for each receiving frequency, and a sounding range are provided. Receiving gain setting means for setting the receiving gain in the receiver. The invention according to claim 2 further includes a reception frequency reading means for reading a reception frequency of the receiver.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a preferred embodiment of the present invention, automatic sensitivity is activated by a key switch on an operation panel.

[0018]

FIG. 1 is a block diagram of a fish finder according to the present invention. 1 is a control unit including the CPU 110. Reference numeral 2 denotes a transmission / reception unit, which is composed of a switching unit 20, a transmitter 21, a receiver 22, and a reading control unit 23, as shown in the detailed diagram of FIG. 3 is an LC for synthesizing and displaying an image of the detection signal and an image of a scale, a character or the like.
It is a D display. Reference numeral 4 denotes an operation panel unit including a switch including an automatic sensitivity setting switch 40, a knob including a sounding range knob 43, and the like. A transmitter / receiver 5 transmits a transmission signal from the transmitter 21 as an ultrasonic signal into water, and further converts a received ultrasonic reflected signal into an electric signal. In the present embodiment, the transducer 5 has a frequency of 50 kHz.
It is possible to support two frequencies of z and 200 kHz.

The CPU 110 recognizes the state of each knob and switch including the screen changeover switch 44 read from the operation panel unit 4 through the operation panel read control unit 107, and controls the display mode, the depth measurement range, the transmission command, and the like. .
The CPU 110 can read a frequency that can be received by the receiver 22 through the reading control unit 23 by a dip switch (not shown). The transmission and reception control unit 108
A transmission signal of a frequency designated from the above two frequencies is sent to the transmitter 21 according to a transmission command of U110. The transmitter 21 drives the transmitter / receiver 5 by amplifying the transmission signal transmitted from the transmission / reception controller 108 to a predetermined power. The receiver 22 operates at 50 kHz and 20 kHz according to a command from the CPU 110.
It is possible to select a frequency of 0 kHz and set a reception gain (sensitivity). Further, the receiver 22 can receive, amplify, and detect a signal of a frequency corresponding to the transducer 5.

The processing at the time of power-on according to the present invention will be described with reference to FIG. Power / brightness switch 45
When the power is turned on, the power-on process shown in FIG. 4 is executed. In S41, the CPU 110 reads the state of a dip switch (not shown) in the receiver 22 through the reading control unit 23, and identifies a receivable frequency of the receiver 22. That is, the CPU 110 acquires an ID number determined for each transmission / reception frequency from the state of the dip switch (not shown). Subsequently, in S42, the CPU 110 sets the I
Based on the D number, the data for setting the automatic reception gain (sensitivity) held in the ROM 109a is copied to the RAM 109b for a frequency that the transmitter / receiver 5 and the receiver 22 can support. The data for automatic reception gain setting is determined to a predetermined value in association with the transmission / reception frequency and the sounding range.

The reception gain setting in the present invention includes automatic sensitivity setting and manual sensitivity setting. By pressing the switch 40, the two are alternately selected. That is, when the switch 40 is pressed, the reception gain setting means switches the automatic sensitivity setting to the manual sensitivity setting and the manual sensitivity setting to the automatic sensitivity setting.

The manual sensitivity processing will be described. CPU 11 through operation panel unit 4 and operation panel reading control unit 107
0 checks whether the automatic sensitivity is selected. In the case of manual sensitivity (when automatic sensitivity is not selected), C
The PU 110 reads the content of the screen changeover switch 44 through the operation panel reading control unit 107. Based on the read content, the CPU 110 sets the reception frequency of the receiver 22 through the reading control unit 23 and, at the same time, reads the values of the sensitivity knobs 42 a and 42 b through the operation panel unit 4 and the operation panel read control unit 107. The reception gain (sensitivity) of each frequency is set. Thereby, the receiver 22 is set to the optimum reception gain for each frequency. The contents of the sounding range knob 43 as the sounding range setting means are also read, and the display on the LCD is set as the read sounding range. By the above operation, a detection signal in the sounding range corresponding to the sounding range knob 43 read from the operation panel unit 4 through the operation panel reading control unit 107 is displayed on the LCD display.

Regarding the processing of the automatic sensitivity in the present invention,
This will be described with reference to FIG. When the automatic sensitivity is selected, in step S51, the contents of the screen changeover switch 44 are read through the operation panel unit 4 and the operation panel read control unit 107, and whether the transmission / reception is one of the high frequency or the low frequency (reception) It is confirmed whether the operation is alternately performed at two frequencies of a high frequency or a low frequency) and a high frequency and a low frequency. At the same time, in S52, it is determined whether or not the sounding range knob 43 has been operated. If the operation has been performed, the contents of the sounding range knob 43 are read in S53, and the RAM 10 is read.
From the data for automatic reception gain (sensitivity) setting stored in 9b, reception gain (sensitivity) data in the sounding range at the corresponding frequency is read. Then, in S54,
Reception gain (sensitivity) of the receiver 22 through the reading control unit 23
Set. At the same time, the frequency specified by the screen switch 44 is set to the receiver 22 through the reading control unit 23. If the sounding range knob 43 is not operated, the process of S53 is not performed, and the process of S54 is performed using the reception gain (sensitivity) data of the sounding range set last time. With this configuration, even when the automatic sensitivity is selected, it is possible to set the reception gain for setting the optimum reception gain in the receiver from the transmission / reception frequency and the sounding range.
In response to a transmission command from the CPU 110, a transmission signal is transmitted from the transmitter 21 inside the transmission / reception unit 2 through the switching unit 20.
And an ultrasonic signal is launched into the sea. The reflected signal from the sea is converted into an electric signal by the transducer 5 and input to the receiver 22 through the switching unit 20 inside the transmitting / receiving unit 2. The receiver 22 amplifies and detects the reflected signal based on the transmission / reception frequency and the optimum reception gain set from the sounding range through the reading control unit 23 by the CPU 110,
The signal is output to the A / D converter 101 as a detection signal. The detection signal output from the receiver for which the optimum reception gain has been set is processed by the control unit 1, and becomes an appropriate detection image as shown in FIG.

In this embodiment, by reading the state of a dip switch (not shown) in the receiver 22, the automatic reception gain (sensitivity) stored in the ROM 109a is read.
The configuration in which the setting data is copied to the RAM 109b has been described. However, the configuration is not necessarily limited to this embodiment.
The data for automatic reception gain (sensitivity) setting held in the ROM 109a may be copied to the RAM 109b by operating the menu switch 41 or the like of the operation panel unit 4. The present invention is not limited to the present embodiment, and the transmitter / receiver 5 and the transmitting / receiving unit 2
Each can be implemented in plurals.

[0025]

Since the attenuation characteristic differs depending on the frequency in the sea, the reception gain is set in accordance with the frequency and the sounding range, and the reception gain accompanying the change of the sounding range, the rapid change of the seafloor topography, and / or the change of the transmission / reception frequency. The effect of realizing the automatic sensitivity setting of the fish finder which has solved the setting problem can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a fish finder according to the present invention.

FIG. 2 is a detailed view of a transmitting / receiving unit of the fish finder according to the present invention.

FIG. 3 is a configuration diagram of an operation panel of the fish finder according to the present invention.

FIG. 4 is a flowchart for explaining a power-on process according to the present invention;

FIG. 5 is a flowchart illustrating automatic sensitivity processing according to the present invention.

FIG. 6 is an example of a detection image when the reception gain is set large.

FIG. 7 is an example of a detection image when the reception gain is set small.

FIG. 8 is an example of a detection image when the reception gain is set appropriately.

FIG. 9 is a flowchart of a conventional automatic sensitivity processing example.

FIG. 10 is a graph showing attenuation characteristics against sea bottom and sea water at an ultrasonic frequency of 50 kHz.

FIG. 11 is a graph showing attenuation characteristics against sea bottom and sea water at an ultrasonic frequency of 200 kHz.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control part 2 Transmission / reception part 3 LCD display 4 Operation panel part 5 Transceiver 101 A / D conversion part 102 Detected video memory 103 Video synthesis part 104 Write / scroll control part 105 Graphic video memory 106 Writing control part 107 Operation Panel reading control unit 108 Transmission / reception control unit 109a ROM 109b RAM 110 CPU 20 Switching unit 21 Transmitter 22 Receiver 23 Reading control unit 201 Submarine detection signal detection unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J083 AA02 AB01 AC29 AD06 AE04 AE06 AF15 BA01 BB12 BE48 EA39 EA41 EB04

Claims (2)

[Claims] 1. A fish finder capable of transmitting and receiving a plurality of frequencies, wherein a receiving gain is set to a receiver according to a set sounding range, a sounding range setting means for designating a measuring range in water, and a plurality of sounding range setting means for each receiving frequency. A fish finder comprising: a reception gain storage unit for storing the reception gain of the above; and a reception gain setting unit for setting the reception gain in the receiver according to the sounding range. 2. The fish finder according to claim 1, further comprising a reception frequency reading means for reading a reception frequency of the receiver.