JPH04282484A - Fish finder having ship velosity meter - Google Patents

Abstract

PURPOSE:To obtain a detector having a cheap and accurate velocity display by providing both functional of an ultrasonic ship velocity meter and a fish finder. CONSTITUTION:On a transmitter/receiver 3, a vertical direction vibration group 3a and an oblique direction vibrator group 3b are provided. The ultrasonic frequency electric signal from a transmitter 1 is switched by a switcher 2 to input the signal either into the vertical direction vibrator group 3a or the oblique direction vibrator group 3b and ultrasonic beams are transmitted in the vertical and oblique directions and received from directions. The receiver signal from the transmitter/receiver 3 is amplified by a common receiver 4 and output. If the receiver output is the reception signal from the vertical direction, it is processed in a fish finder signal processor 5. If it is the reception signal from the oblique direction, it is processed in a ship velocity processor 7 to display the velocity on the same screen.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fish finder that is less expensive and has a highly accurate ship speed display function by sharing the common functions of a fish finder and an ultrasonic Doppler log.

0002

2. Description of the Related Art The mainstream of fish finders has been so-called color fish finders that display fish school information on color cathode ray tubes. Therefore, by displaying various fishing information on a single color CRT, it has come to function as a fishing display. In addition, pleasure boats are required to display ship speed on the same CRT as one of the voyage information.

Conventionally, in order to satisfy such requirements, an ultrasonic boat speedometer and a fish finder were required, as shown in FIG. A system consisting of a number of devices was required.

Furthermore, in systems that require low cost, such as pleasure boats, a propeller as shown in FIG. The speed was displayed using rotation in proportion to the ship's speed.

[0005]

[Problem to be solved by the invention] However, the above 2
The example system has the following drawbacks. The system shown in Figure 5 requires a transducer for the fish finder and the ultrasonic speedometer, which requires a large amount of construction work on the bottom of the ship.It also requires two systems, making it expensive. are doing. Furthermore, the system shown in FIG. 6 converts the number of rotations of the propeller into speed, so it has a drawback that there are many ship speed errors.

[0006] The present invention aims to solve the above-mentioned drawbacks, and by sharing the functions of an ultrasonic ship speedometer and a fish finder, it is possible to obtain an inexpensive and highly accurate ship speed. An object of the present invention is to provide a fish finder having a display function.

[0007]

Means for Solving the Problems The present invention has the following means for achieving the above object. That is, the fish finder having a boat speedometer of the present invention includes a first group of ultrasonic transducers that transmits and receives an ultrasonic beam vertically from the bottom of the boat, and a first group of ultrasonic transducers that transmits and receives an ultrasonic beam diagonally downward at a predetermined angle from the horizontal. a transducer having a second group of transducers that transmit and receive waves; a transmitter that outputs a pulsed ultrasonic frequency electrical signal; and a transmitter that outputs a pulsed ultrasonic frequency electric signal; a switch for switching whether to cause the first ultrasonic transducer group to perform the ultrasonic transducer or the second ultrasonic transducer group; a receiver to amplify the received signal from the transducer; and an output of the receiver. a fish detection signal processing unit that receives a signal and processes the signal as a fish detection signal when the signal is a received signal from a vertical direction;
a ship speed processing unit that receives the output signal of the receiver and performs ship speed detection processing when the output signal is a received signal from an oblique direction;
a selection circuit that causes a fish detection signal processing section to process the signal when the receiver output is a received signal from a vertical direction, and causes the boat speed processing section to process the signal when the receiver output is a received signal from an oblique direction; a control unit that determines the transmission timing of the switch, the switching timing of the switch, and the operation timing of the selection circuit;
The present invention is characterized by comprising: a display unit that displays a fish detection image and a boat speed display on the same screen; and;

[0008]

[Operation] In the present invention, as in the above-mentioned means structure, the transducer is provided with a group of transducers for the vertical direction and a group of transducers for the oblique direction, and the ultrasonic frequency electricity from one transmitter is The signal can be applied to the vertical ultrasonic transducer group or the oblique ultrasonic transducer group of the transducer using a switch, so that the signal can be applied to the vertical ultrasonic transducer group or the oblique ultrasonic transducer group. Ultrasonic beams are transmitted and received.

[0009] Received signals from the transducer are amplified by a common receiver and output. And by the operation of the selection circuit,
When the receiver output is a received signal from the vertical direction, it is processed by the fish detection signal processing section, and when the receiver output is a received signal from the diagonal direction, it is processed by the boat speed processing section. It has become.

It is well known that if the angle of depression of the oblique beam is θ, the ultrasonic frequency is f0, the speed of sound in water is C, and the speed of the ship is V, then the Doppler frequency fd is expressed by the following equation 1. Then, by detecting the Doppler frequency fd from the amplified received signal in the ship speed processing section, Equation 1 can be converted and the ship speed V can be obtained from Equation 2 below.

[0011]

[Math 1]

0012

[Math 2]

Incidentally, when θ=90°, that is, in the vertical direction, cos90°=0 in Equation 1, so the Doppler frequency cannot be obtained, and therefore the ship speed V cannot be determined.

As described above, since the direction of the transmitting and receiving beams can be switched, it is possible to obtain both fish detection information and ship speed information with one transmitter, one transducer, and one receiver. These two pieces of information can be displayed on the same screen of the display unit using well-known technology.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Normally, the ultrasonic beam of a fish finder is emitted vertically from the bottom of a boat, as shown in Figure 2, and the reflected echoes are processed and displayed on a color cathode ray tube or the like. On the other hand, the ultrasonic speedometer
The beam is fired at a certain angle θ (generally 60° is selected) with respect to the ship's direction of travel, as shown in Figure 3, the Doppler frequency in the beam direction of the ship's speed is detected, and the calculation process is performed using Equation 2 above. to display the ship speed. The present invention attempts to display the boat speed on the display section of the fish finder by, for example, performing the above operations alternately.

FIG. 1 is a block diagram showing the configuration of an apparatus according to an embodiment of the present invention that performs the above operations. The transducer 3 includes an ultrasonic transducer group 3a that transmits and receives ultrasonic beams in the vertical direction and an ultrasonic transducer group 3b that transmits and receives ultrasonic beams in the direction of the depression angle θ. The switching device 2 converts the ultrasonic frequency electric signal from the transmitter 1 into the ultrasonic transducer group 3a according to the switching signal from the calculation unit 8.
It has a function of switching between supplying the ultrasonic transducer to the ultrasonic transducer group 3b and the ultrasonic transducer group 3b.

Now, a case will be described in which the switching device 2 is switched to supply an ultrasonic frequency electric signal to the ultrasonic transducer group 3a. The ultrasonic transducer group 3a transmits ultrasonic beams in the vertical direction and receives reflected waves from the vertical direction. The received signal is sent to the receiver 4 via the switch 2 and the TR circuit 10.
where it is amplified to the required level.

The amplified received signal is sent to a fish detection signal processing section 5 and a gate circuit 6. The gate circuit 6 operates the fish detection signal processing unit 5 according to the selection signal from the calculation unit when the switching signal from the calculation unit is a signal for transmitting and receiving waves in the vertical direction, and vice versa. When is a signal for performing wave transmission/reception in an oblique direction, a gate signal is sent to the fish detection signal processing section 5 to stop the operation of the fish detection signal processing section 5. In this way, the fish detection signal processing section 5 performs rectification and A/D conversion processing, and the fish detection data is sent to the calculation section 8 at a constant period determined by the display range.

The calculation unit 8 processes the fish detection data into display data, and displays the data on the display unit 9 along with ship speed data, which will be explained next.
and displayed as an image as shown in FIG. Next, a case will be described in which the switching device 2 is switched to supply an ultrasonic frequency electric signal to the ultrasonic transducer group 3b.

The ultrasonic transducer group 3b transmits an ultrasonic beam in an oblique direction with an angle of depression θ, and receives reflected waves from the oblique direction. The received signal is sent to the switch 2 in the same way as when transmitting and receiving waves in the vertical direction.
The signal is then sent to the receiver 4 via the TR circuit 10, where it is amplified to the required level.

The amplified received signal is supplied to both the fish finding signal processing section 5 and the gate circuit 6 as described above, but the fish finding signal processing section 5 receives the gate signal from the gate circuit 6. Since the operation is stopped by , no fish detection data is output.

On the other hand, the gate circuit 6 extracts the amplified received signal from the receiver 4 from the seafloor echo at depths where seafloor echoes are detected, and from the volumetric reverberation signal received immediately after transmission at depths where seafloor echoes are not detected. In order to obtain this, the input received signal is gated and extracted. Note that when the switch is switched to transmit and receive waves in the vertical direction, the gate circuit is in a blank gate state and does not pass the input signal to the output. In this way, the gate circuit corresponds to the selection circuit referred to in the means configuration.

The received signal thus extracted by the gate circuit 6 is sent to the boat speed processing section 7, where the Doppler frequency is detected. This signal indicating the Doppler frequency is sent to the calculation unit 8, where the ship speed V is calculated using Equation 2, and the signal is further processed into display data and sent to the display unit 9, where it is displayed on the screen displaying the fish detection image. 4 14.5k
It is displayed like t.

With the above operations, the activation signal sent from the calculation unit 8 to the transmitter 1, the switching signal sent to the switch 2, and the selection signal sent to the gate circuit 6 are synchronized so that their respective operations do not deviate. It is taken. Therefore, a part of the calculation section corresponds to the control section in terms of means configuration. Furthermore, although a typical example of the switching operation of the switching device 2 is to alternately switch each transmission cycle, the switching operation is not limited to this. Furthermore, the ultrasonic beam can be switched in the vertical direction or in the obliquely downward direction by controlling the excitation phase of each transducer in one transducer group.

[0025] Thus, the device of the present invention does not require separate installation of two systems, a conventional fish finder and a boat speedometer.
By sharing the transmitter, receiver, and display unit, and by sharing most of the transducer and calculation unit, one system can have the functions of both a fish finder and a boat speedometer.

[0026]

As explained above, the fish finder of the present invention uses a switching device to switch the ultrasonic transducer group that transmits and receives ultrasonic waves, and also uses a selection circuit to change the fish detection signal. The operation of the processing section and ship speed processing section can also be switched, and the data from either is processed into display data by the calculation section and displayed on the same display screen, so the transmitter, transducer, and receiver The advantage of this system is that it is possible to share the instrument, calculation section, and display section, and it is not necessary to install two separate systems as in the past, making it possible to configure a fish finder with a highly accurate Doppler speedometer at a low cost. be.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram when an ultrasonic beam is transmitted and received in a vertical direction from the bottom of a ship.

FIG. 3 is an explanatory diagram when an ultrasonic beam is transmitted and received obliquely downward from the bottom of the ship at an angle of depression θ.

FIG. 4 is a diagram showing an example of a display image of the device of the present invention.

FIG. 5 is a system diagram for displaying boat speed on a conventional fish finder.

FIG. 6 is a system diagram when a boat speed is displayed using a propeller for boat speed detection in a conventional fish finder.

FIG. 7 is a schematic diagram of a propeller for ship speed detection.

[Explanation of symbols]

1 Transmitter 2 Switcher 3 Transducer/receiver 4 Receiver 5 Fish detection signal processing section 6 Gate circuit 7 Ship speed processing section 8 Arithmetic section 9 Display section 10 TR circuit

Claims (1)

[Claims] [Claim 1] A first group of ultrasonic transducers that transmits and receives ultrasonic beams vertically from the bottom of the ship, and a second group of transducers that transmits and receives ultrasonic beams diagonally downward at a predetermined angle from the horizontal. a transducer having; a transmitter that outputs a pulsed ultrasonic frequency electric signal; and a first ultrasonic transducer group of the transducer that transmits and receives waves by the output signal from the transmitter according to a switching signal; a switch that switches whether the signal is transmitted or transmitted to a second group of ultrasonic transducers; a receiver that amplifies the received signal from the transducer; and a receiver that receives the output signal of the receiver and receives the wave from the vertical direction. A fish detection signal processing unit that processes the signal as a fish detection signal when it is a signal; A boat speed processing unit that receives the output signal of the receiver and performs boat speed detection processing when it is a received signal from an oblique direction; a selection circuit that causes a fish detection signal processing unit to process the signal when the receiver output is a received signal from a vertical direction, and causes the boat speed processing unit to process the signal when the receiver output is a received signal from an oblique direction; a control unit that determines the transmission timing of the switching device, the switching timing of the switch, and the operation timing of the selection circuit; a display unit that displays the fish detection image and the boat speed display on the same screen;
A fish finder having a boat speedometer, characterized by comprising: