JPH063450A - Ultrasonic remote water temperature measuring device - Google Patents

Abstract

(57) [Summary] [Purpose] Cancel the installation error of the wave transmitter and measure the accurate water temperature distribution. [Structure] 16 sets two operation modes. In the initial value setting mode, 7 generates a trigger pulse every time a command is input from 16, 13 outputs a depression angle control signal to 5, and the depth is deepened stepwise, but 4 is drooped in water of a certain depth. While taking the water temperature into 13 and obtaining the sound velocity at that depth, ultrasonic waves are emitted from 1 toward the water of that depth, the time difference between the waves received at 2 and 3 is measured at 12, and taken into 13 The actual depression angle of the transmitted beam is calculated from the speed of sound, the time difference, and the distance between the receivers, which is stored as an initial value in association with the depression angle control signal. In the measurement mode, while automatically changing the depression angle of the transmitted beam, the sound velocity is calculated from the actual depression angle of the transmitted beam, the time difference and the distance between the receivers, which are calculated and obtained in the initial value setting mode. The water temperature is calculated from the calculated sound velocity, and the underwater temperature distribution in which the installation error of 1 is canceled is displayed on 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic remote water temperature measuring device for measuring water temperatures at various depths in water by using the propagation time of ultrasonic waves.

[0002]

2. Description of the Related Art With a sound sensor such as a thermistor widely used for temperature detection, the surface water temperature near the water surface can be measured relatively easily, but it is difficult to measure the temperature at a specific depth in water. Therefore, in recent years, an apparatus has been proposed which measures the temperature distribution in water using ultrasonic waves without using such a sound sensing element.

That is, in the conventional water temperature measuring device using this ultrasonic wave, the directivity direction of the received beam is a fixed direction in which the reflection points of each transmitted ultrasonic wave are connected when the depression angle of the transmitter is changed. The two wave receivers that are set as described above are arranged at a fixed distance, and the time from the time of wave transmission to the time of wave reception by each of the two wave receivers is measured, and the wave receiver and wave receiver are received. Calculate the ultrasonic wave reflection point in water from the distance to the vessel and the depression angle of the transmitted and received beams, that is, calculate the propagation distance of the sound wave geometrically, and measure it with the propagation time. To obtain the propagation velocity,
The water temperature is calculated.

[0004]

In the above-mentioned conventional water temperature measuring apparatus, in order to calculate the propagation distance of ultrasonic waves, the distance between the transmitter and the receiver, the transmitting beam and the receiving beam are calculated. Since the reflection point of ultrasonic waves in water is calculated from the depression angle of the water, there is a problem that the accuracy of the depression angle of the acoustic wave beam greatly affects the measurement accuracy of the water temperature, making accurate water temperature measurement difficult.

That is, since the wave transmitter and the wave receiver are of a flat type, they are installed horizontally on the bottom of the ship, etc., but they are not always installed accurately horizontally, and the depression angle set by the device is not always correct. There is often a difference between the actual depression angle of the sound beam and the depression angle, and such a difference appears as an error in the measured water temperature. At this time, the installation error of the wave receiver is not a problem because the depression angle of the receiving beam is fixed to a constant value, but the installation error of the wave transmitter is difficult to correct and affects the accuracy of the measured water temperature. For example, when the distance between the wave transmitter and the wave receiver is 20 m and the depression angle is 45 °, if the angle of this deviation is 1 °, the measurement error of the water temperature will be a value of about 10 ° C. is there.

An object of the present invention is to provide an ultrasonic remote water temperature measuring device capable of canceling a mounting error of a transmitter and accurately measuring temperature distribution in water by ultrasonic waves.

[0007]

In order to achieve the above object, the ultrasonic remote water temperature measuring device of the present invention has the following constitution. That is, the ultrasonic remote water temperature measuring device of the present invention includes a transmitter that emits ultrasonic waves into water in response to the generation of a trigger pulse; in the initial value setting mode, a measurement mode is input each time a command is input from the operation panel. Sometimes a trigger circuit that automatically generates the trigger pulse at a predetermined interval; and a depression angle control circuit that receives the depression angle control signal and sets the direction of the transmission beam of the transmitter; disposed at a fixed distance Done 2
Two wave receivers, each of which is formed by orienting a received beam in a predetermined direction which is a direction in which reflection points of transmitted ultrasonic waves at various depression angles are connected; A timer that measures the time difference from the ultrasonic wave transmission of the wave vessel to the wave reception of each of the two wave receivers; a water temperature meter that measures the water temperature of various depths depending on the water temperature; initial value setting mode At this time, the depression angle control signal is output in response to a command from the operation panel, and the actual speed of the transmitted beam is calculated from the speed of sound obtained from the water temperature by the water thermometer, the time difference, and the distance between the two wave receivers. The depression angle is calculated, the actual depression angle value of the transmitted beam obtained by the calculation is stored in association with the output depression angle control signal, and in the measurement mode, the depression angle control signal is generated in response to the trigger pulse from the trigger circuit. Is output, and the output depression angle An arithmetic unit that calculates the sound velocity from the calculated actual depression angle of the transmitted beam corresponding to the control signal, the time difference, and the distance between the two receivers, and calculates the water temperature from the calculated sound velocity. And; are provided.

[0008]

Next, the operation of the ultrasonic remote water temperature measuring device of the present invention constructed as described above will be described. In the present invention, in the initial value setting mode, while ultrasonic waves are emitted toward a certain depth of water to measure the time difference between received waves, the sound velocity is obtained from the water temperature at that depth by the water thermometer, and this time difference and sound velocity are measured. Calculate the actual depression angle of the transmitted beam from the distance between the receivers,
The depression angle of the transmitter beam is stored in the initial value in association with the depression angle control signal by operating the depression angle of the transmitter stepwise from the operation panel for various depths. While changing the sound velocity, the sound velocity is calculated from the actual depression angle value of the transmission beam, the time difference, and the distance between the two wave receivers, which are calculated and obtained in the initial value setting mode, and the water temperature is calculated from the calculated and acquired sound velocity.

Therefore, even if there is a mounting error in the transmitter, it can be canceled and the temperature distribution in water can be measured accurately and simply and quickly.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an ultrasonic remote water temperature measuring device according to an embodiment of the present invention. The ultrasonic remote water temperature measuring device of the present invention,
It operates in two modes: "initial value setting mode" and "measurement mode". This is set by the operation panel 16,
The initial value setting mode is an operation mode in which the transmitter 1 collects the depression angle of the acoustic wave beam actually transmitted as an initial value,
This is performed once before the actual measurement of the water temperature distribution at the beginning of operation of the device or when changing the measurement water area.

In the initial value setting mode, the trigger circuit 7 generates a trigger pulse each time a start command (not shown) is input from the operation panel 16 by a mode designation (not shown) from the operation panel 16 and transmits it. In the measurement mode, a trigger pulse is automatically generated in a constant cycle, and the trigger pulse is given to the transmitter 6, the timer 12 and the calculator 13.

The arithmetic unit 13 also outputs a depression angle control signal for setting the depression angle of the transmitted beam of the transmitter 1 to the depression angle control circuit 5, and the timer 12 and the A / D converter 15 at that depression angle.
Although the calculation to be described later is performed based on the output of the above, etc., it is provided with a memory, and a depression angle control signal for setting the depression angle of the transmitted beam of the transmitter 1 is stored in correspondence with the address. For example, when the access is sequentially performed from the head address, the depression angle control signal having a smaller value is sequentially read.

The operation unit 1 is operated in the initial value setting mode by the mode designation from the operation panel 16.
Each time the depression angle output command from 6 is input, one address in the memory is accessed each time a trigger pulse is input from the trigger circuit in the measurement mode. As a result, the depression angle control signal having a smaller value is sequentially read, and ultrasonic waves are transmitted in order from a shallow depth of water to a deep depth.

Next, the wave transmitter 1 and the wave receivers 2 and 3 are attached to the bottom or the port side of the ship, but the wave receiver 2 and the wave receiver 3 are the same.
Are arranged with a certain distance, and each of the received beams is formed to be directed in a predetermined direction which is a direction in which reflection points of transmitted ultrasonic waves at various depression angles are connected. Further, the water temperature gauge 4 is hung from the port side to measure the water temperature at various depths in the water. Specifically, for example, it is as shown in FIG.

[0015] In FIG. 2, the water temperature distribution, for convenience in the depth range L _a certain T ₁ ° C. description, the depth range L _b is a constant T ₂ ° C., the wave transmitter 1 first depth range L _A sound wave (a) is emitted at a depression angle of θ ₁ to measure the temperature of _a , and then a sound wave (b) is emitted at a depression angle of θ ₂ to measure the temperature in the water depth range L _b . The sound wave (a) is assumed to be reflected at points A ₁ and B ₁ . Wave (b), since the temperature of the water depth range L _a same L _b are different refracted at point Q of the boundary, depth range L
depression angle of the sound beam in a _b are different theta ₂ 'and theta _2, but the reflected at point A ₂ and point B _2.

At this time, the direction of the received beam of the wave receiver 2 coincides with the direction in which the points A ₁ and A ₂ are connected, and the direction of the received beam of the wave receiver 3 is point B ₁ and the point B _1. It is set so as to coincide with the direction in which B ₂ is connected. As is clear from the illustrated example, the depression angle of the received beam is usually set to 90 °.
The distance between the two is d. The distance from the transmitter 1 is irrelevant.

The water thermometer 4 is hung from the port side and first measures the water temperature T ₁ in the water depth range L _a , and then the water depth range L a.
It is operated to measure the water temperature T ₂ of _b . This is provided in view of the mounting error of the wave transmitter 1, and its output is digitized by the A / D converter 15 and given to the calculator 13, which is used in the initial value setting mode. It is not used in the measurement mode.

First, in the initial value setting mode, the mode is set by the operation panel 16 and the actual depression angle of the transmitted beam of the transmitter 1 is obtained by the following procedure. Hanging set the water temperature gauge 4 to a depth range L _a. The measured value is taken into the arithmetic unit 13 via the A / D converter 15. In addition, the operation panel 16 is operated to issue a depression angle output command to the calculator 13 and a start command to the trigger circuit 7. The calculator 13 outputs a depression angle control signal having the depression angle θ ₁ to the depression angle control circuit 5, and the trigger circuit 7 outputs a trigger pulse to the transmitter 6 and the timer 12.

The transmitter 6 amplifies a burst wave having a certain frequency based on the trigger pulse from the trigger circuit 7 and transmits the signal to the transmitter 1.
A pulsed sound wave (a) is emitted from the device, and the direction of the transmitted beam is set to θ ₁ based on the instruction from the depression angle control circuit 5.

The reflected sound wave at the point A ₁ is received by the receiver 2, detected by the detection circuit 10 via the amplifier 8, and the timer 12 measures the time from the trigger pulse input to the reception detection. To be done. The reflected sound wave at the point B ₁ is received by the wave receiver 3, detected by the detection circuit 11 via the amplifier 9, and the timer 12 measures the time from the trigger pulse input to the reception detection. . Then, in the timer 12, the wave receiver 2
The time difference τ ₁ of the sound waves received in (3) and (3) is measured and given to the calculator 13.

[0021] Here, when the speed of sound in water depths ranging L _a and C _1, the relationship between the depression angle theta ₁ of the actual transmission beam of the time difference tau ₁ and the transmitter 1 is given by Equation 1.

[0022]

[Formula 1] d [(1 / cos θ ₁ ) + tan θ ₁ ] = C ₁ τ ₁

From equation (1), cos θ ₁ becomes equation (2), so the depression angle θ ₁ becomes equation (3).

[0024]

[Equation 2] cos θ ₁ = (2C ₁ τ ₁ d) / (C ₁ ² τ ₁ ² + d ² )

[0025]

[Equation 3] θ ₁ = cos ⁻¹ [(2C ₁ τ ₁ d) / (C ₁ ² τ ₁ ² + d ² )]

That is, the calculator 13 converts the sound velocity C ₁ from the water temperature T ₁ measured by the water temperature gauge 4 and applies it to the above equation to obtain the actual depression angle θ ₁ of the transmitted beam of the transmitter ₁ . calculate. Then, in the illustrated example, although it is equal to the set depression angle,
Stores the content of the output depression angle control signal and the depression angle acquired this time in association with each other.

Next, the water thermometer 4 is set to hang in the water depth range L _b . The measured value is sent to the arithmetic unit 1 via the A / D converter 15.
Taken in 3. In addition, the operation panel 16 is operated to issue a depression angle output command to the calculator 13 and a start command to the trigger circuit 7. The calculator 13 outputs a depression angle control signal containing the depression angle θ ₂ to the depression angle control circuit 5, and the trigger circuit 7
Outputs a trigger pulse to the transmitter 6 and the timer 12.

As a result, the wave transmitter 1 emits a sound wave (b) at a depression angle θ ₂ . The sound wave (b) has a depression angle θ ₂ and a water depth range L.
_{It travels} in _a and reaches the boundary between the water depth range L _a and the same L _b , and refracts there to make a depression angle θ different from θ ₂ in the water depth range L _b .
_Although traveling at ₂ ′, the reflected sound wave at the point A ₂ within the water depth range L _b is received by the wave receiver ₂ , and the reflected sound wave at the point B ₂ is received by the wave receiver 3. That is, the time difference τ ₂ is output from the timer 12 to the calculator 13.

Here, assuming that the sound velocity in the water depth range L _b is C ₂ , the relationship between the time difference τ ₂ and the depression angle θ ₂ ′ is given by the equation 4 similar to the equation 1.

[0030]

## EQU4 ## d [(1 / cos θ ₂ ′) + tan θ ₂ ′] = C ₂ τ ₂

From Expression 4, θ ₂ ′ becomes Expression 5, but since Snell's law establishes Expression 6, the relationship between θ ₂ and θ ₂ ′ becomes Expression 7, and if Expression 5 is substituted into this The actual depression angle θ ₂ is obtained.

[0032]

[Equation 5] θ ₂ ′ = cos ⁻¹ [(2C ₂ τ ₂ d) / (C ₂ ² τ ₂ ² + d ² )]

[0033]

[Equation 6] C ₁ / cos θ ₂ = C ₂ / cos θ ₂ ′

[0034]

[Equation 7] θ ₂ = cos ^-1 [(C ₁ / C ₂ ) cos θ ₂ ′]

That is, the calculator 13 converts the sound velocity C ₂ from the water temperature T ₂ measured by the water temperature gauge 4 in the same manner as above, and applies it to the above equation to calculate the actual transmission beam of the transmitter 1. Calculate the depression angle θ ₂ . Although it is equal to the set depression angle in the illustrated example, the calculator 13 stores the content of the depression angle control signal output and the depression angle acquired this time in association with each other.

Thus, in the initial value setting mode,
Gradually increase the depression angle and collect the actual depression angle of the transmitted beam as an initial value.

Next, in the measurement mode, the operation panel 16
According to the mode setting, the trigger circuit 7 repeatedly generates the trigger pulse at a constant cycle, and the calculator 13 outputs the depression angle control signal each time the trigger pulse is input.

As a result, the transmitter 1 controls the depression angle in order from the small depression angle to the large depression angle, emits ultrasonic waves in order from the shallow water depth to the deep water depth, and measures the time difference τ at each water depth. Input to the calculator 13.

In the computing unit 13, the depression angle θ of the actual transmission beam corresponding to the depression angle control signal output within the input period of the trigger pulse, that is, in each water depth range.
Is read from the memory, the sound velocity C is calculated using the actual depression angle θ, the distance d, and the time difference τ (Equation 8), and the water temperature T is calculated from the calculated sound velocity C and output to the display unit 14. Accurate water temperature was obtained by canceling the mounting error of the wave transmitter 1.

[0040]

[Equation 8] C = (d / τ) [(1 / cos θ) + tan θ]

Thus, the temperature of each water depth range from the upper layer to the lower layer is continuously displayed on the display 14, and a desired water temperature distribution can be obtained.

[0042]

As described above, according to the ultrasonic remote water temperature measuring apparatus of the present invention, in the initial value setting mode, ultrasonic waves are emitted toward the water of a certain depth to measure the time difference between received waves. On the other hand, the sound velocity is obtained from the water temperature at that depth by the water temperature gauge, and the actual depression angle of the transmitted beam is calculated from this time difference, the sound velocity and the distance between the receivers, and this is associated with the depression angle control signal as the initial value. The depression angle of the transmitter is operated in steps from the operation panel for various depths.In measurement mode, the depression angle of the transmission beam is automatically changed, and calculation is performed in the initial value setting mode. Since the sound velocity is calculated from the actual depression angle value of the transmitted beam and the time difference and the distance between the two receivers, the water temperature is calculated from the relational expression between the calculated sound velocity and the water temperature. There is a mounting error in the wave Accurately the temperature distribution of the water to cancel it, and there is an effect of easily and quickly measured.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an ultrasonic remote water temperature measuring device according to an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram.

[Explanation of symbols]

 1 wave transmitter 2 wave receiver 3 wave receiver 4 water temperature meter 5 depression angle control circuit 6 transmitter 7 trigger circuit 8 amplifier 9 amplifier 10 detection circuit 11 detection circuit 12 timer 13 calculator 14 indicator 15 A / D converter 16 control panel

Claims (1)

[Claims] 1. A transmitter that emits ultrasonic waves into water in response to the generation of a trigger pulse; every time a command is input from the operation panel in the initial value setting mode, and at a predetermined interval automatically in the measurement mode. A trigger circuit that generates the trigger pulse at; and a depression angle control circuit that receives the depression angle control signal and sets the directivity direction of the transmission beam of the transmitter; two wave receivers that are arranged at a fixed distance. And two wave receivers each of which forms a received beam in a predetermined direction which is a direction in which reflection points of transmitted ultrasonic waves at various depression angles are connected;
A timer for measuring the time difference from the time of ultrasonic wave transmission of the wave transmitter to the time of reception of each of the two wave receivers;
A water thermometer that hangs in the water and measures the water temperature at various depths;
In the initial value setting mode, the depression angle control signal is output in response to a command from the operation panel, and the wave is transmitted from the sound velocity obtained from the water temperature by the water temperature gauge, the time difference, and the distance between the two wave receivers. The actual depression angle of the beam is calculated, and the calculated actual depression angle value of the transmitted beam is stored in association with the output depression angle control signal, and in the measurement mode, in response to the trigger pulse from the trigger circuit. The depression angle control signal is output, and the sound velocity is calculated from the actual depression angle value of the transmitted and acquired transmission beam corresponding to the output depression angle control signal, the time difference, and the distance between the two receivers, An ultrasonic remote water temperature measuring device, comprising: a calculator that calculates the water temperature from the calculated sound velocity;