JPH01206280A - Detection of submerged position - Google Patents

Abstract

PURPOSE:To detect the position of a master station, by performing the response of a sonic wave signal between the master station provided so as to be movable in water and a plurality of sub-stations and measuring each distance on the basis of the propagation time of said sonic wave signal. CONSTITUTION:The main body part 4 of a submerged detector is provided to an investigation ship 3 and a robot 1 performs searching operation by its terminal machine while moving on the bottom of the sea. A master station 6 having a sonic wave transmitting/receiving function is provided to the robot 1 and sub-stations 8a, 8b, 8c for transmitting and receiving a sonic wave are respectively mounted on bodies 7 arranged in water. A start signal is sent out from the master station 6 and a response signal is transmitted from the sub-station 8a in response to said start signal. After the start signal is transmitted from the master station 6, the time h1 up to the reception of the response signal is detected in the master station 6 and the value 1/2 the product of said time and submerged sonic velocity V is measured as the straight distance x1 between the master station 6 and the sub-station 8a. In the same way, the straight distances x2, x3 between the master station 6 and the sub-stations 8b, 8c are measured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an underwater position detection method, and in particular, to an underwater position detection method, in which one master station is movably provided underwater and a plurality of slave stations are placed at predetermined positions. The base station is installed, the baseline length between adjacent slave stations is measured, the installation position of each slave station is determined based on the baseline length, and a sound wave signal is transmitted between the master station and the slave station. The present invention relates to an underwater position detection method that measures each distance between a master station and a slave station based on the propagation time of the sound wave signal, and detects the position of a moving master station.

(Prior Art) Recently, robots have been used to conduct underwater oil-related surveys, seabed surveys, etc., and a transponder method, for example, has been adopted as a method for detecting the position of the robot.

The transponder method uses the response of sound waves to determine the distance between a master station and multiple slave stations (transponders) placed around it, and detects the two-dimensional or three-dimensional position of the master station. A master station is attached to the robot, and a slave station is attached to an object for underwater installation, so that the position of the robot can be detected.

Prior to detection, as mentioned above, it is necessary to measure the baseline length between slave stations in order to determine the installation position of each slave station, and this measurement work can be performed, for example, as follows. There is.

In other words, the survey ship is sailed so as to cross approximately the center between adjacent slave stations, and at that time, the direct distance between the survey ship and the slave stations is determined by responding with a sound wave signal to each slave station. In addition, the water depth was determined by navigating over slave stations, and the baseline length between slave stations was measured based on this data.

(Problem to be Solved by the Invention) However, in the conventional case, in order to measure all baseline lengths between each slave station, a research vessel must repeatedly navigate between and over the slave stations. Therefore, the work is extremely time-consuming and time-consuming, and furthermore, the measurement accuracy is low because the sonic signals are transmitted and received from a moving research vessel.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an underwater position detection method that can easily and accurately measure the baseline length.

(Means for Solving the Problems) In order to achieve such an object, the present invention, in the underwater position detection method described at the beginning, measures each of the baseline lengths at the base station and the slave station. measuring the direct distance between each of two adjacent slave stations of a station based on the propagation time of the sound wave signal by performing a sound wave signal response between the base station and each of the slave stations; A first sound wave signal is transmitted from the station to one of the adjacent slave stations, and a second sound wave signal is transmitted from the one slave station to the other adjacent slave station in response to the first sound wave signal. ,
transmitting a third sound wave signal from the other slave station to the master station in response to the second sound wave signal, and transit time required from transmission of the first sound wave signal to reception of the third sound wave signal at the master station; The route distance is measured based on the route distance, and each of the direct distances is subtracted from the route distance.

(Function) With the above configuration, in the underwater position detection method of the present invention, when the first sound wave signal is transmitted from the master station to one of the slave stations,
A second sound wave signal is transmitted from one slave station to the other slave station, and a third sound wave signal is further transmitted from the other slave station to the master station, and the route distance X is obtained based on the overall route propagation time. The baseline length is determined by subtracting the direct distance between the master station and each of the slave stations from the distance X.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

First, before explaining the underwater position detection method of the present invention,
With reference to FIG. 1, the overall configuration of an underwater position detection device that performs the underwater position detection method of the present invention will be explained. FIG. 1 is an overall configuration diagram of the underwater position detection device.

In the figure, reference numeral 1 indicates a robot movably installed on the seabed, and is connected to a research ship 3 on the sea via a cable 2. The research vessel 3 is provided with a main body 4 of an underwater detection device, and the robot 1 is provided with a terminal 5 of an underwater detection device such as a magnetic sensor or an underwater camera. The robot 1 performs a detection operation with its terminal jfA5 while moving on the seabed, and sends the detection signal to the main body 4 of the research vessel 3 via the cable 2. Also robot l
A master station 6 having a function of transmitting and receiving sound waves is provided. Each of 7 is an object for underwater installation, and each of the objects 7 for underwater installation has slave stations 8a and 8b that transmit and receive sound waves.
, 8c are each attached.

An example of the underwater position detection method of the present invention using the above device will be sequentially explained below.

■ Installation of slave stations 8a, 8b, 8c and master station 6 The research vessel 3 is moved and three underwater installation objects 7 and one robot 1 are placed on the seabed.

Each of the underwater installation objects 7 has two parts as shown in FIG.
Dimensionally placed at each vertex of an approximately equilateral triangle,
The robot 1 is positioned approximately at the center of the equilateral triangle formed by the underwater installation object 7. In this way, the slave stations 8a and 8b.

8c and the master station 6 are installed in the detection seabed area.

■ Baseline length B L + , B L t ,
Measurement A of B L s, master station 6 and slave stations 8a, 8b,
Measurement of the direct distance (slant range length) between the master station 6 and each of the slave stations 8c First, an activation signal is transmitted from the master station 6 to the slave stations 8a, 8b, and 8c. As this starting signal, a double pulse signal as shown in FIG. 3 is used. That is, 13 ms after the generation of the first pulse p1 with a width of 2 ms, a second pulse p with a width of 2 ms is further generated and transmitted using a carrier wave of 40 KIIz. In response to the activation signal, the slave station 8a transmits a response signal formed by a linear frequency modulated wave having a center frequency of 50 KHz.

FIG. 4 is a configuration diagram of the slave station 8a, in which the slave station 8a includes a receiving circuit 9, an activation signal detection circuit 10, a response mode selection circuit II, a delay circuit 12, and a transmission signal generation circuit! 3 and transmission command circuit 1
4 and a transmitting circuit 15. The slave station activation signal received by the receiving circuit 9 is transmitted to the activation signal detection circuit 1.
0, the double pulse interval and the reception frequencies of the first and second pulses are detected and a specific activation signal is detected, and the response mode selection circuit 11 selects a response signal corresponding to the detected activation signal. The above selected response signal is given to the transmission signal generation circuit 13 via the delay circuit 12 on the one hand, and to the transmission signal generation circuit 13 via the transmission command circuit 14 on the other hand. When the active signal is output from the transmission command circuit 14 after a certain period of time from the selection, the above-mentioned linear frequency modulated wave signal is output from the transmission signal generation circuit 13. This linear frequency modulated wave signal is transmitted from the transmitting circuit 15 to the master station 6 as a response signal,
The master station 6 performs pulse compression processing on the response signal of this linear frequency modulated wave signal.

The data of the signal generated from the transmission signal generation circuit 13 is R
The address is stored in the OM, and the address is switched in response to the selection response signal, and the corresponding signal is extracted. If this signal generation method using a ROM is adopted, since the crystal is used as a clock, reproducibility is good, a stable output can be obtained, and data conversion of the output signal can be easily performed.

In addition, as described above, if the double pulse signal is used as the starting signal for identification, the starting signal can be reliably distinguished from the external signal, preventing malfunctions, and the linear frequency modulated signal can be used as the response signal. By using the signal formed by Ru.

As described above, the activation signal is transmitted from the master station 6, and in response, a response signal is transmitted from the slave station 8a.After the activation signal is transmitted from the master station 6, the response signal is received by the master station 6. 1/2 of the product of that time and the underwater sound speed V is measured as the direct distance XI between the master station 6 and the slave station 8a.

Then, in the same manner as above, the master station 6 and the slave station 8b.

Direct distances X9 and x3 between 8c are measured. Child station 8b.

Linear frequency modulated wave signals with center frequencies of 60 KHz and 70 KHz are used as the carrier waves of the response signals from each of the 8c, and due to the difference in frequency, after signal processing such as pulse compression on the master station 6 side, the corresponding child Identify the station.

B. Measuring the transit distances X5, X2, and X Regarding the measurement of the transit distances of the master station 6 and slave stations 8a and 8b,
This will be explained with reference to the time chart shown in FIG.

First, the master station 6 transmits an activation signal (first sound wave signal) only to the slave station 8a. This starting signal includes the first pulse P,
Frequency is 40KHz, second pulse 22 frequency is 50KH
A double pulse signal of z is used. In response to this activation signal, the receiving circuit 9 in the slave station 8a outputs the received signals P3 and P.
4 is output, and in response to the received signals P5 and P4, the activation signal detection circuit 10 outputs the activation signal detection signal P, and in response to this activation signal detection pulse P, the activation signal ( A second sound wave signal) is transmitted from the transmitting circuit 15. As this starting signal, the first pulse P6, the second pulse P? A double pulse signal with a specific frequency is used. In response to this activation signal, the slave station 8b operates in the same manner as the slave station 8a, and sequentially outputs the received signals Pg, Ps, and the detection signal P1°, and outputs and transmits a response signal pH consisting of a compressed pulse signal. , in the master station 6, the received signal P1
2, and in response, outputs a detection signal PI3 to complete the reception.

C. Calculation of baseline lengths BL, 1Bl, , B L z Then, detect the transit propagation time T1 from the transmission of the activation signal at the master station 6 to the reception of the response signal from the slave station 8b, and By multiplying the time obtained by subtracting the delay time t+,jt at the slave stations 8a and 8b from the propagation time T and the underwater sound speed V, the route distance from the master station 6 to the slave station 8a to the slave station 8b to the master station 6 is
1 is measured.

Then, the baseline length BL between slave stations 8a and 8b,
The measurement is performed by subtracting the direct distances X+ and X1 from the route distance X1.

The measurement of the transit distances X t and X 3 is also performed in the same manner as the above X+, and the baseline length BL between the slave stations 8b and 8c is measured by subtracting the direct distance X t + X 3 from the transit distance X.
Furthermore, the baseline length BL3 between the slave station 8c and Ba is measured by subtracting the direct distance X3+XI from the route distance X3.

When measuring the above-mentioned route distances X, , K I-Iz.

The frequency shall be 70KHz.

■ Position determination of each slave station 8a, 8b, 8c When the baseline lengths BLI, BL, BL, between each slave station 8a, 8b, 8c are measured as described above,
Research vessel 3 and slave stations 8a and 8b capable of detecting absolute coordinate positions
, 8c and measure the direct distance therebetween, geometrically determining the direct distance between the slave stations 8a and 8c.

8b, 8. Determine the absolute coordinate position of each c.

■ Detection of the position of the master station 6 by measuring the distances between the master station 6 and the slave stations 8a, 8b, 8c, and the master station 6 moving between the slave stations 8a, 8b, 8c and the respective slave stations 8a, 8b. , 8c, and the master station 6 and each slave station 8a, 8
The absolute coordinate position of the master station 6 is detected relative to the position of each of the slave stations 8a, 8b, and 8c by sequentially measuring the distance between them.

Here, the above-mentioned master station 6 and slave stations 8a, 8b, 8c
The method of measuring the distance between
A performed in measuring the baseline length in (■) above.
The master station 6 and slave stations 8a and 8b.

The method of measuring the direct distance between each of the points 8c and 8c is the same.

(Effects of the Invention) As described above, according to the present invention, the baseline length between each slave station required for underwater position detection can be measured by transmitting the first sound wave signal from the master station to the slave station. , a second sound wave signal is transmitted from the slave station to the other slave station based on the first sound wave signal,
Furthermore, a third sound wave signal is transmitted from the other slave station to the master station,
The route distance is obtained based on the total route propagation time of each sound wave signal, and it is calculated by subtracting the direct distance between the master station and each of the two slave stations from this route distance. There is no need to sail the survey vessel to measure the baseline length, and the baseline length can be measured in a short time without any effort after installing the master station and slave stations, significantly shortening the overall survey period. be done.

Further, since the measurement operation is performed based on the response of the sound wave signal between the master station and the slave station in the stopped state, the baseline measurement accuracy is also improved.

[Brief explanation of the drawing]

Figures 1 to 5 relate to embodiments of the present invention, with Figure 1 showing the overall configuration of the underwater position detection device, Figure 2 showing the arrangement of the master station and slave stations, and Figure 3 showing the signals used. 4 is a block diagram of the slave station, and FIG. 5 is a time chart for explaining the operation. 6 is a master station, and 8a, 8b, 8c are slave stations. Agent Patent Attorney Oka 1) Hide Kazu Figure 1 Figure 2 211111111

Claims (1)

[Claims] (1) Install one master station movably underwater, install multiple slave stations at predetermined positions, measure the baseline lengths between adjacent slave stations, and adjust the baseline lengths to Based on this, the installation position of each slave station is determined, a sound wave signal is responded between the master station and the slave station, each distance between the master station and the slave station is measured based on the propagation time of the sound wave signal, and the distance between the master station and the slave station is measured and moved. In an underwater position detection method for detecting the position of a master station, each of the baseline lengths is measured, the direct distance between the master station and each of two adjacent slave stations is measured, and the direct distance between the base station and each of two adjacent slave stations is measured. transmitting a sound wave signal response between the master station and each of the slave stations, measuring the sound wave signal based on the propagation time of the sound wave signal, and transmitting a first sound wave signal from the master station to one of the adjacent slave stations; transmitting a second sound wave signal from the one slave station to the other adjacent slave station in response to the first sound wave signal;
transmitting a third sound wave signal from the other slave station to the master station in response to the second sound wave signal, and transit time required from transmission of the first sound wave signal to reception of the third sound wave signal at the master station; An underwater position detection method characterized by: measuring a route distance based on the route distance, and subtracting each of the direct distances from the route distance.