CN114362867B - A Time Synchronization and Data Storage Working Method for Deep Drag System - Google Patents

Abstract

The invention discloses a time synchronization and data storage working method for a deep drawing system, which belongs to the technical field of physical marine equipment, wherein the position information and time information of a scientific investigation ship can be acquired in real time through a GNSS positioning system, and the position information of the deep drawing system can be acquired through a USBL positioning system; the deep drawing system is connected with the scientific investigation ship through a photoelectric composite cable, wherein sensors such as multi-beam, side-scan sonar, shallow stratum profiler and the like are mounted on the deep drawing system; initializing a deep towed time system by a GNSS receiver, and synchronizing the time of the system by using a PPS signal of the GNSS receiver and a deep towed crystal oscillator; after time synchronization is completed, the deep drawing system can acquire data, and the acquired data is uploaded to the scientific investigation ship through the photoelectric composite cable and is stored locally, so that the data is prevented from being lost, and the problem of real-time data loss caused by communication interruption of the photoelectric composite cable in the existing deep drawing system is solved.

Description

A Time Synchronization and Data Storage Working Method for Deep Drag System

technical field

The invention belongs to the technical field of physical marine equipment, and in particular relates to a working method for time synchronization and data storage of a deep towing system.

Background technique

With the continuous development of marine science, exploring the ocean and developing the ocean has gradually become a new strategic direction for our country. The deep sea exploration environment is harsh and the complexity is high. At present, the multi-equipment integrated deep towing system is mainly used in the world. This system can carry out long-term deep-sea operations and is suitable for large-scale seabed surveying and mapping, seabed target search, seabed geological exploration and other operations. .

The deep towing system is a streamer-type deep-sea submersible, which integrates multiple oceanographic survey instruments, such as multi-beam bathymetry instruments, shallow strata profilers, side-scan sonar systems, and detects data through photoelectric composite The cables are uploaded to the deck unit for storage and data post-processing. It can detect seawater physical and chemical parameters, seabed topography and shallow strata profiles for a long time. The current deep towing system generally adopts the method of uploading data to the mother ship laboratory for data fusion through the photoelectric composite cable. If the photoelectric composite cable is squeezed or stretched, the communication will be interrupted, and all real-time data transmission will be lost during the interruption. .

Contents of the invention

The present invention proposes a time synchronization and data storage working method for deep towing system, which stores data collected by equipment such as multi-beam, shallow profile, and side scan in the deep tow system for local storage + real-time uploading method to prevent Loss of data due to failure of the optical composite cable.

The present invention specifically adopts the following technical solutions:

A working method for time synchronization and data storage for a deep dragging system, comprising:

S1. Obtain the time information and the position information of the scientific research ship through the GNSS receiver and send the PPS signal;

S2. Configure the clock tree for the time through the crystal oscillator on the deep dragging system, and provide the reference time of the deep dragging system itself;

S3. After the configuration of the clock tree of the deep towing system itself is completed, receive the satellite system time information transmitted by the GNSS receiver on the scientific research ship and perform time initialization. Time synchronization operation;

S4. After the time synchronization of the deep towing system is completed, the combination of the USBL positioning system carried on the scientific research ship with the INS system and DVL completes the positioning and speed measurement of the deep towing system;

S5. Collect data from the multi-beam bathymetry system, shallow stratum profiler, and side-scan sonar sensor, upload the collected data to the scientific research ship through the photoelectric composite cable, and store the data locally in the deep towing system for backup to prevent data lost.

Preferably, the time information is used to initialize the time of the deep towing system, and the PPS signal is used to interrupt the deep towing system with pulse per second.

Preferably, the step S1 includes:

S1.1. When the scientific research ship conducts scientific research experiments in the ocean, obtain high-precision time information and ship position information (X, Y, Z) through the GNSS receiver installed on the ship;

S1.2. Configure the data protocol sent by the GNSS receiver, including the time information GPZDA in the NEMA-0183 protocol. The GPZDA information includes UTC date and time information, and the specific format is year, month, day, hour, minute, and second;

S1.3. Configure the GNSS receiver to output the PPS signal. PPS is a second pulse signal. Compared with the NEMA-0183 protocol information, there is no time delay, and it is used for the time synchronization operation of the deep dragging system;

S1.4. The deep towing system is connected to the scientific research vessel through a photoelectric composite cable.

Preferably, said step S2 includes:

S2.1. After the deep drag system is powered on, first reset the clock by default, and then perform the initial configuration of the clock, including setting the level of the voltage regulator, configuring related parameters of the clock source, configuring the system clock source and frequency division coefficient;

S2.2. After configuring the clock system, enable the required peripheral clocks to ensure that the relevant peripherals are in normal use;

S2.3. Configure a timer to prepare for time synchronization.

Preferably, the step S3 includes the following sub-steps:

S3.1. After the clock tree configuration of the deep dragging system is completed, the data sent by the GNSS receiver is received through the photoelectric composite cable, and the GPZDA information is extracted from it;

S3.2. Analyze the extracted UTC time information, and set the offset to extract date and time data according to the NEMA-0183 protocol;

S3.3. The deep drag system configures a PPS signal input pin, and sets an external interrupt for the pin, enables the pin clock enable, and sets the interrupt priority;

S3.4. Turn on the timer, and each time the deep dragging system receives the PPS signal from the photoelectric composite cable, it will clear the counter of the timer, so that the counter starts counting from zero;

S3.5. While receiving the PPS signal, the time system of the deep dragging system will add 1 second to the operation;

S3.6. After the deep drag system equipment is turned on, it starts to store data. While recording a piece of data, read the value of the counter in the timer to get the time within one second, plus the time of the deep drag system itself, to get the exact time of the data;

S3.7. After the above configuration, the deep towing system has completed the time synchronization with the laboratory of the scientific research ship, which is convenient for subsequent data fusion and data processing.

Preferably, said step S4 includes the following sub-steps:

S4.1. The scientific research ship is equipped with a USBL positioning system, and the deep towing system is equipped with INS and DVL sensors. Among them, INS can measure the attitude information of the deep towing system, and DVL can measure the speed information of the deep towing system;

S4.2.USBL adopts a basic array transducer with 4 array elements, and the 4 array elements form a left-handed rectangular coordinate system, in which array elements 1 and 3 are on the x-axis, and array elements 2 and 4 are on the y-axis , the center of the base array is the coordinate origin O, and the array element spacing is D;

S4.3. Assuming that the underwater cooperative target is located at point S, its coordinates in the matrix coordinate system are (x, y, z), and the direction cosine of the target vector OS is

Among them, α is the angle between the target radial vector and the x-axis, β is the angle between the target radial vector and the y-axis, and R is the target slope distance;

S4.4. The size of the ultra-short baseline positioning matrix is very small relative to the target slant distance, and the incident wave can be approximated as a plane wave, then

Among them, τ _x is the time delay difference of receiving signals of 1 and 3 array elements on the x-axis, and τ _y is the time delay difference of receiving signals of 2 and 4 array elements on the x-axis;

S4.5. Obtained from the delay difference

(x, y) are the plane coordinates of the position of the deep towing system, and the depth position z is measured by the pressure sensor, so the laboratory can know the position information of the deep towing system;

S4.6. Through the INS sensor installed on the deep towing system, the speed, attitude and position information of the deep towing system can be measured;

S4.7. It is known that the position of the deep towing system P at time t ₀ is (P _N (t ₀ ), P _E (t ₀ ), P _U (t ₀ )), and the speed is (V _N (t ₀ ), V _E (t ₀ ), V _U (t ₀ )), and the acceleration of each axis measured by the three-axis accelerometer is (A _N (t ₀ ), A _E (t ₀ ), A _U (t ₀ )), find the position of point P at time t ₁ (P _N (t ₁ ),P _E (t ₁ ),P _U (t ₁ )):

S4.7. DVL measures and records the navigation speed and accumulated voyage of the deep towing system, which is used in the underwater auxiliary navigation system. Through the combination of USBL/INS/DVL and data processing, the position, speed and attitude of the deep towing system are obtained information.

Preferably, step S5 includes the following sub-steps:

S5.1. After the above configuration, the deep dragging system turns on the measuring equipment to work;

S5.2. Collect data from the multi-beam bathymetry system, shallow strata profiler, and side-scan sonar sensors carried on the deep towing system, and upload the collected data to the scientific research ship through the photoelectric composite cable for subsequent data processing ;

S5.3. If the photoelectric composite cable is excessively squeezed or stretched during the data collection process, the communication will be interrupted. During the interruption, in order to prevent the loss of real-time data transmission, a local data storage module is added to the deep dragging system;

S5.4. After adding the local data storage module, during the data collection process, the collected data is uploaded to the scientific research ship laboratory through the photoelectric composite cable, and at the same time, the data is also stored and backed up locally in the deep towing system according to the time synchronization information.

Compared with the prior art, the present invention uses the PPS signal for time synchronization, so that the data of the deep towing system has time characteristics. Through the time synchronization operation, the data with time characteristics can be stored locally, and the data can be directly stored in the hard disk of Shentuo. In this way, data loss caused by the interruption of the optical fiber composite cable can be avoided.

Description of drawings

Fig. 1 is a flow chart of the time synchronization and data storage working method of the present invention.

Detailed ways

The specific embodiment of the present invention will be further described below in conjunction with specific embodiment:

A time synchronization and data storage working method for a deep dragging system, the technical flow chart is shown in Figure 1, including the following steps:

S1. The GNSS receiver is used to obtain the time information and the position information of the scientific research ship, and is also used to send the PPS signal. The time information is used to initialize the time system of the deep tow, and the PPS signal is used to interrupt the second pulse of the deep tow;

S2. The crystal oscillator on the deep drag is used to configure the clock tree of the time system to provide the reference time of the deep drag itself;

S3. After the configuration of the clock tree of the deep towing system itself is completed, the time information of the satellite system transmitted by the GNSS receiver on the scientific research ship is received for time initialization. Time synchronization operation;

S4. After the time synchronization of the deep towing system is completed, the combination of the USBL positioning system carried on the scientific research ship with the INS system and DVL completes the positioning and speed measurement of the deep towing system;

S5. Multi-beam bathymetry system, shallow strata profiler, side-scan sonar and other sensors collect data, upload the collected data to the scientific research ship through the photoelectric composite cable, and also store and backup the data locally in the deep towing system. Prevent data loss.

Step S1 includes the following sub-steps:

S1.1. When the scientific research ship conducts scientific research experiments in the ocean, the GNSS receiver installed on the ship can obtain high-precision time information and ship position information (X, Y, Z);

S1.2. Configure the data protocol sent by the GNSS receiver, including the time information GPZDA in the NEMA-0183 protocol. The GPZDA information includes UTC date and time information, and the specific format is year, month, day, hour, minute, and second;

S1.3. Configure the GNSS receiver to output the PPS signal. PPS is the second pulse signal. Compared with the NEMA-0183 protocol information, there is no time delay, and it can be used for the time synchronization operation of the deep drag system;

S1.4. The deep tug is connected to the scientific research ship through a photoelectric composite cable. The crystal oscillator on the deep tug is used to configure the clock tree of the time system and provide the deep tug itself with its own reference time.

Step S2 includes the following sub-steps:

S2.1. After the deep dragging system is powered on, first reset the clock by default, and then perform the initial configuration of the clock, including setting the level of the voltage regulator, configuring related parameters of the clock source, configuring the system clock source and frequency division coefficient, etc.;

S2.2. After configuring the clock system, enable the required peripheral clocks to ensure that the relevant peripherals are in normal use;

S2.3. Configure a timer to prepare for time synchronization.

Step S3 includes the following sub-steps:

S3.1. After the clock tree configuration of the deep drag system is completed, the data sent by the GNSS receiver can be received through the photoelectric composite cable, and the GPZDA information can be extracted from it;

S3.2. Analyze the extracted UTC time information, and set the offset to extract date and time data according to the NEMA-0183 protocol;

S3.3. The deep drag system configures a PPS signal input pin, and sets an external interrupt for the pin, enables the pin clock enable, and sets the interrupt priority;

S3.4. Turn on the timer, and each time the deep dragging system receives the PPS signal from the photoelectric composite cable, it will clear the counter of the timer, so that the counter starts counting from zero;

S3.5. While receiving the PPS signal, deep dragging its own time system will add 1 second;

S3.6. After the deep drag device is turned on, it starts to store data. While recording a piece of data, it reads the value of the counter in the timer to get the time within one second, plus the time of deep drag itself, to get the data. accurate time;

S3.7. After the above configuration, the deep towing system has completed the time synchronization with the laboratory of the scientific research ship, which is convenient for subsequent data fusion and data processing.

Step S4 includes the following sub-steps:

S4.1. In addition to the need to complete time synchronization, the scientific research ship laboratory needs to know the position and speed information of the deep towing system in real time, so the scientific research ship is equipped with a USBL positioning system, and the deep tow is equipped with INS and DVL sensors. INS can measure the attitude information of deep drag, and DVL can measure the speed information of deep drag;

S4.2.USBL adopts a basic array transducer with 4 array elements, and the 4 array elements form a left-handed rectangular coordinate system, in which array elements 1 and 3 are on the x-axis, and array elements 2 and 4 are on the y-axis , the center of the base array is the coordinate origin O, and the array element spacing is D;

S4.3. Assuming that the underwater cooperative target is located at point S, its coordinates in the matrix coordinate system are (x, y, z), and the direction cosine of the target vector OS is:

Among them, α is the angle between the target radial vector and the x-axis, β is the angle between the target radial vector and the y-axis, and R is the target slope distance;

S4.4. The size of the ultra-short baseline positioning matrix is very small relative to the target slant distance, and the incident wave can be approximated as a plane wave, then

Among them, τ _x is the time delay difference of receiving signals of 1 and 3 array elements on the x-axis, and τ _y is the time delay difference of receiving signals of 2 and 4 array elements on the x-axis;

S4.5. Obtained from the delay difference

(x, y) are the plane coordinates of the deep towing position, and the depth position z is measured by the pressure sensor, so the laboratory can know the position information of the deep towing;

S4.6. Through the INS sensor installed on the deep tow, the speed, attitude and position information of the deep tow can be measured;

S4.7. It is known that the position of deep drag P at time t ₀ is (P _N (t ₀ ), P _E (t ₀ ), P _U (t ₀ )), and the speed is (V _N (t ₀ ), V _E (t ₀ ), V _U (t ₀ )), and the acceleration of each axis measured by the three-axis accelerometer is (A _N (t ₀ ), A _E (t ₀ ), A _U (t ₀ ) ), find the position of point P at time t ₁ (P _N (t ₁ ),P _E (t ₁ ),P _U (t ₁ )):

S4.7.DVL can measure and record the sailing speed and accumulated voyage of the deep tow, which is used in the underwater auxiliary navigation system. Through the combination of USBL/INS/DVL and data processing, the position, speed and attitude of the deep tow can be obtained information.

Step S5 includes the following sub-steps:

S5.1. After the above configuration, the deep dragging system can start the measuring equipment to work;

S5.2. The multi-beam bathymetry system, shallow stratum profiler, side-scan sonar and other sensors carried on the deep towing carry out data collection, and the collected data is uploaded to the scientific research ship through the photoelectric composite cable for subsequent data processing;

S5.3. If the photoelectric composite cable is excessively squeezed or stretched during the data collection process, it will cause communication interruption, and all real-time data transmission will be lost during the interruption. In order to prevent data loss, it is necessary to use the deep drag system Add local data storage module;

S5.4. After adding the local data storage module, during the data collection process, the collected data is uploaded to the scientific research ship laboratory through the photoelectric composite cable, and at the same time, the data is also stored and backed up locally in the deep towing system according to the time synchronization information.

Of course, the above descriptions are not intended to limit the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or replacements made by those skilled in the art within the scope of the present invention shall also belong to the present invention. protection scope of the invention.

Claims (6)

1. A time synchronization and data storage working method for deep dragging system, characterized in that, comprising: S1. Obtain the time information and the position information of the scientific research ship through the GNSS receiver and send the PPS signal; S2. Configure the clock tree for the time through the crystal oscillator on the deep dragging system, and provide the reference time of the deep dragging system itself; S3. After the configuration of the clock tree of the deep towing system itself is completed, receive the satellite system time information transmitted by the GNSS receiver on the scientific research ship and perform time initialization. Time synchronization operation; S4. After the time synchronization of the deep towing system is completed, the combination of the USBL positioning system carried on the scientific research ship with the INS system and DVL completes the positioning and speed measurement of the deep towing system; S5. Collect data from the multi-beam bathymetry system, shallow stratum profiler, and side-scan sonar sensor, upload the collected data to the scientific research ship through the photoelectric composite cable, and store the data locally in the deep towing system for backup to prevent data The loss; the step S1 includes: S1.1. When the scientific research ship conducts scientific research experiments in the ocean, obtain high-precision time information and ship position information (X, Y, Z) through the GNSS receiver installed on the ship; S1.2. Configure the data protocol sent by the GNSS receiver, including the time information GPZDA in the NEMA-0183 protocol. The GPZDA information includes UTC date and time information, and the specific format is year, month, day, hour, minute, and second; S1.3. Configure the GNSS receiver to output the PPS signal. PPS is a second pulse signal. Compared with the NEMA-0183 protocol information, there is no time delay, and it is used for the time synchronization operation of the deep dragging system; S1.4. The deep towing system is connected to the scientific research vessel through a photoelectric composite cable. 2. The time synchronization and data storage working method for the deep tow system as claimed in claim 1, wherein the time information is used to initialize the time of the deep tow system, and the PPS signal is used to initialize the time of the deep tow system. Perform a second pulse interrupt. 3. The time synchronization and data storage working method for deep dragging system according to claim 1, characterized in that, said step S2 comprises: S2.1. After the deep drag system is powered on, first reset the clock by default, and then perform the initial configuration of the clock, including setting the level of the voltage regulator, configuring related parameters of the clock source, configuring the system clock source and frequency division coefficient; S2.2. After configuring the clock system, enable the required peripheral clocks to ensure that the relevant peripherals are in normal use; S2.3. Configure a timer to prepare for time synchronization. 4. The time synchronization and data storage working method for deep dragging system according to claim 1, characterized in that, said step S3 comprises the following sub-steps: S3.1. After the clock tree configuration of the deep dragging system is completed, the data sent by the GNSS receiver is received through the photoelectric composite cable, and the GPZDA information is extracted from it; S3.2. Analyze the extracted UTC time information, and set the offset to extract date and time data according to the NEMA-0183 protocol; S3.3. The deep drag system configures a PPS signal input pin, and sets an external interrupt for the pin, enables the pin clock enable, and sets the interrupt priority; S3.4. Turn on the timer, and each time the deep dragging system receives the PPS signal from the photoelectric composite cable, it will clear the counter of the timer, so that the counter starts counting from zero; S3.5. While receiving the PPS signal, the time system of the deep dragging system will add 1 second to the operation; S3.6. After the deep drag system equipment is turned on, it starts to store data. While recording a piece of data, read the value of the counter in the timer to get the time within one second, plus the time of the deep drag system itself, to get the exact time of the data; S3.7. After the above configuration, the deep towing system has completed the time synchronization with the laboratory of the scientific research ship, which is convenient for subsequent data fusion and data processing. 5. The time synchronization and data storage working method for deep dragging system according to claim 1, characterized in that, said step S4 comprises the following sub-steps: S4.1. The scientific research ship is equipped with a USBL positioning system, and the deep towing system is equipped with INS and DVL sensors. Among them, INS can measure the attitude information of the deep towing system, and DVL can measure the speed information of the deep towing system; S4.2.USBL adopts a basic array transducer with 4 array elements, and the 4 array elements form a left-handed Cartesian coordinate system, in which array elements 1 and 3 are on the x-axis, and array elements 2 and 4 are on the y-axis , the center of the base array is the coordinate origin O, and the array element spacing is D; S4.3. Assuming that the underwater cooperative target is located at point S, its coordinates in the matrix coordinate system are (x, y, z), and the direction cosine of the target vector OS is Among them, α is the angle between the target radial vector and the x-axis, β is the angle between the target radial vector and the y-axis, and R is the target slope distance; S4.4. The size of the ultra-short baseline positioning matrix is very small relative to the target slant distance, and the incident wave can be approximated as a plane wave, then Among them, τ _x is the time delay difference of receiving signals of 1 and 3 array elements on the x-axis, and τ _y is the time delay difference of receiving signals of 2 and 4 array elements on the x-axis; S4.5. Obtained from the delay difference (x, y) are the plane coordinates of the position of the deep towing system, and the depth position z is measured by the pressure sensor, so the laboratory can know the position information of the deep towing system; S4.6. Through the INS sensor installed on the deep towing system, the speed, attitude and position information of the deep towing system can be measured; S4.7. It is known that the position of the deep towing system P at time t ₀ is (P _N (t ₀ ), P _E (t ₀ ), P _U (t ₀ )), and the speed is (V _N (t ₀ ), V _E (t ₀ ), V _U (t ₀ )), and the acceleration of each axis measured by the three-axis accelerometer is (A _N (t ₀ ), A _E (t ₀ ), A _U (t ₀ )), find the position of point P at time t ₁ (P _N (t ₁ ),P _E (t ₁ ),P _U (t ₁ )): S4.7. DVL measures and records the navigation speed and cumulative voyage of the deep towing system, which is used in the underwater auxiliary navigation system. Through the combination of USBL/INS/DVL and data processing, the position, speed and attitude of the deep towing system are obtained information. 6. The time synchronization and data storage working method for deep drag system according to claim 1, characterized in that step S5 comprises the following sub-steps: S5.1. After the above configuration, the deep dragging system turns on the measuring equipment to work; S5.2. Collect data from the multi-beam bathymetry system, shallow stratum profiler, and side-scan sonar sensors mounted on the deep towing system, and upload the collected data to the scientific research ship through the photoelectric composite cable for subsequent data processing ; S5.3. If the photoelectric composite cable is excessively squeezed or stretched during the data collection process, it will cause communication interruption. During the interruption period, in order to prevent the loss of real-time data transmission, a local data storage module is added to the deep dragging system; S5.4. After adding the local data storage module, during the data collection process, the collected data is uploaded to the scientific research ship laboratory through the photoelectric composite cable, and at the same time, the data is also stored and backed up locally in the deep towing system according to the time synchronization information.