JPS63136843A - Underwater communication system - Google Patents

Abstract

PURPOSE:To enable a stable communication which is strong against a disturbance by providing an oscillator which oscillates in plural frequencies corresponding to the input of a switch in a transmission part and outputting a corresponding voice which is previously stored when an ultorasonic signal is demodulated and specified frequency of signals are detected more than specified level in a reception side. CONSTITUTION:By operating a switch, an encoder circuit 2 is made to be started, so that an analog switch 14 is selected and driven to select the specified frequency of the oscillators 13n-13n-1. The signal is modulated, for instance in terms of AM modulation, in a modulation circuit 3 and amplified in a power amplifier 4 in order that the unltrasonic signal is radiated into the water from an ultrasonic transducer 6 through a circulator 5. The signal is inputted in a pre-amplification part 7 through the circulator 5 and amplified in the reception part. Next, after the signal is detected in a demodulation circuit 8 it is transmitted to a tone decoder circuit 9 consisting of plural frequencies of band pass filter. And when the signal level exceeds the specified value, the demodulation circuit 8 decides that the signal is inputted and transmits a carrier detection signal to a decoder circuit 10.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an underwater communication system, and more specifically, to an underwater communication system carried by 5CUBA Dipers and used for communication between 5CUBA Dipers or between 5CUBA Dipers and a mother ship at sea. The present invention relates to a preferred portable wireless communication system.

Prior Art Recently, dangerous work on the seabed and other underwater areas has been increasing due to ocean development, and among the divers engaged in the work, 5 Cuba
Daiper accounts for a large proportion. Also, - The number of 5-cuba dippers for leisure is rapidly increasing. However, at present, there is no means of communication between fellow Daipers or between the Daiper and the mother ship at sea, so a wireless means of communication is desperately needed in terms of safety and work efficiency. Compared to the diving method in which a person wears a diving suit and receives air from a ship at sea, the communication method used by the 5cubB Diper, which carries an air cylinder on its back and does not require a lifeline, essentially uses wireless communication. Of course it is desired.

Unlike in the air, electromagnetic waves and light cannot be used as communication means in water, and ultrasonic waves (or sound waves) are usually used as the wave motion.

When considering wireless communication using ultrasonic waves for the 5-Cuba Diaper, the following two technical issues can be considered.

(1) Establishment of a man-machine interface between humans and transmitting/receiving equipment. (Since you are holding a mouthpiece to inhale air from the cylinder, it is difficult to speak freely. Ordinary earphones cannot be used underwater.) (2) Echo distortion due to multiple reflections from the seabed and sea surface. Establish a communication method that eliminates interference between multiple groups and prevents interference between multiple groups.

As a means to address the above technical problem (1), ・Conventionally,
The method used is to use a helmet that covers the entire head, supply air into the helmet, and use a microphone near the lips and earphones near both ears. Another method was to supply air to the face using a face mask that covers only the face rather than the entire head, and to use a lip microphone and bone conduction earphones.

However, in the former case, a helmet is required, which is bulky and inconvenient, and in the latter case, there is a risk of water entering through the gap between the mask and the face, making it impossible to move the jaw sufficiently. be. In any case,
This method was very dangerous because it caused fear in the diapers. Furthermore, there is no effective method for dealing with the above-mentioned technical problem (2), and conventionally only AM or SSR-AM has been used using sound waves as a wave medium.

The present invention corresponds to the communication method of the 5CUBA Diaper, more specifically corresponds to the above technical problem (1), and relates to the transmission and reception of the Diaper.
In Cuba diving, as mentioned above, the diver carries an air cylinder on his back and holds a mouthpiece in his mouth to inhale the air supplied from the cylinder, so he cannot speak freely. I used a department-specific helmet or a face mask, but
It was extremely inconvenient for Daiper to use and was not put to practical use.

Purpose The present invention was made in view of the above-mentioned circumstances.
In particular, the purpose of this invention is to provide an underwater communication system that can be carried by 5CUBA Diapers and wirelessly communicate with other 5CUBA Diapers or between 5CUBA Diapers and a mother ship.

Configuration In order to achieve the above object, the present invention has a transmitter that includes a switch that can set a plurality of modes, and an oscillator that oscillates at a plurality of frequencies in response to the input of the switch. The output signal is analog-modulated and sent out as an ultrasonic signal, and the receiving section demodulates the ultrasonic signal and when a signal of a specified frequency is detected at a specified level or higher, the corresponding pre-stored audio is output. 6, which is characterized in that it is outputted from a speech synthesis circuit, will be described based on embodiments of the present invention.

11th I is an electrical block diagram for explaining an example of a communication device suitable for use in the underwater communication system according to the present invention, in which 1 is an input switch, 2 is an encoder, and 3 is a modulation circuit. , 4 is a power amplifier, 5 is a circulator, 6
is a transducer, 7 is a preamplifier, 8 is a demodulation circuit,
9 is a tone decoder, 10 is a decoder, 11 is a power amplifier, 12 is a bone conduction earphone, 13I, ~13n-+
are oscillators that oscillate frequencies fO to fn-l, respectively, and 14 is an analog switch. The input switch 1 is attached to the arm of the dialer, etc., and the encoder circuit 2 is started by operating the switch corresponding to a command. The encoder circuit 2 generates a signal for selecting signals of a plurality of frequencies.
The analog switch 14 is selectively driven by the output signal to select a predetermined frequency of the oscillators 13n to 13n-l.

The modulation circuit 3 performs, for example, AM modulation on this signal, the power amplifier 4 amplifies the signal, the signal passes through the circulator 5, and the ultrasonic transducer 6 radiates the ultrasonic signal into the water.

In the receiving section, the signal received by the ultrasonic transducer 6 is input to the preamplifier section 7 via the circulator 5 and amplified. Next, after being detected by a demodulation circuit 8, the signal is sent to a tone decoder circuit 9 consisting of bandpass filters of a plurality of frequencies. In order to cope with amplitude fluctuations of the ultrasonic signal underwater, AGC is applied to the preamplifier section 7 from the demodulation circuit 8 in order to stabilize the amount of demodulation. Furthermore, when the signal level exceeds a specified value, the demodulation circuit 8 determines that a signal has been input, and sends a carrier detection signal to the decoder circuit 10.

FIG. 2 is a detailed diagram of the tone decoder circuit 9 shown in FIG. -fn
−+ band pass filter groups 9Qo to 9 an−+, and the output of each band pass filter is detected by the detection circuits 9bo to 9.
After detection at bn-+, comparators 9co to 9c
When a signal of a predetermined level or higher is input through n-+, the output signal is turned ON. These signals are connected to an AND circuit 9do.
~ If you input it to 9dn-l.

The output corresponding to the combination of modulation frequencies of the input signals is turned on. If n8 class frequencies of f and -fn-+ are used as modulation frequencies, and n is 7, and two frequency signals are combined to represent one piece of information, then 1, (:, = 21 of 21
It can transmit different types of information.

When the carrier detection signal is ON and the output of the AND circuit is also ON, the decoder circuit 10 outputs the corresponding code to the speech synthesis output circuit.

The audio synthesis output unit reads out the corresponding pre-recorded audio data from the ROM, converts it from D/A, and sends it out as an analog audio output.The six divers can listen to this signal using bone conduction earphones 12.

Note that as a voice synthesis method, there is a method that uses PCM data.5Furthermore, if compressed data such as ADPCM method or Percoll method is used, the capacity of ROM for recording audio data can be reduced. I can do it.

The frequency of the ultrasonic wave is, for example, a 50 KHz signal used as a carrier, and the length of the signal needs to be sufficiently longer than the time required for AGC pull-in.

In the above explanation, AM modulation is used as an example of the modulation method, but other modulation methods such as FM modulation and SSB are also possible. Although a transducer is used for transmission and reception, two transducers may be used separately for transmission and reception.

In addition, one way to improve signal detection accuracy with this method is to turn on the carrier detection signal, turn on the output of the tone decoder, and then turn on either of these signals.
It may be determined that normal reception has been made when the time to become FF is longer than a specified time. Further, although the oscillators 13o to 13n-+ of fn to fn-l are shown as an example on the transmitting side, it is also possible to generate signals using, for example, two synthesizer type oscillators.

effect As is clear from the above description, one aspect of the present invention is as follows.

(a) Underwater, wireless communication is possible between the dialers or between the dialers and people on board, and furthermore, since no microphone input is required, it is safe and easy to use even for beginners.

(b) Since modulation is performed using signals of multiple frequencies, stable communication that is resistant to interference can be performed even if the ultrasonic signal is reflected underwater and multipath occurs.

There are advantages such as

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram for explaining an example of a communication device suitable for use in the underwater communication system according to the present invention, and FIG. 2 is a detailed circuit diagram of the tone decoder circuit 9 shown in FIG. 1. be. 1...Input switch, 2...Encoder, 3...
Modulation circuit, 4... Power amplifier, 5... Circulator, 6... Transducer, 7... Preamplifier, 8... Demodulation circuit, 9... Tone decoder, 10...
··decoder. 11...Power amplifier, 12...Bone conduction earphone. 13o to 13n-+... Oscillator, 14... Analog switch.

Claims (2)

[Claims] (1) The transmitter has a switch that can set multiple modes and an oscillator that oscillates at multiple frequencies in response to the input of the switch, and the output signal of the oscillator is analog-modulated to generate an ultrasonic wave signal. The receiving section demodulates the ultrasonic signal and outputs the corresponding pre-stored voice from the voice synthesis circuit when a signal of a prescribed frequency is detected at a prescribed level or higher. Underwater communication method. (2) Underwater communication system according to claim (1), characterized in that normal reception is determined when a signal of a specified frequency can be continuously received for a specified period of time or more. .