Marine hydrological data acquisition device and communication method based on Tiantong satellite

Abstract

The invention discloses a Tiantong satellite-based marine hydrological data acquisition device and communication method, and the device comprises a marine data buoy center which is used for acquiring marine hydrological data, carrying out the packaging processing according to a user-defined communication format, and transmitting the data to a ground data receiving and processing center in a short message form through a Tiantong satellite communication link; the processor is also used for receiving instructions of the ground data receiving and processing center for corresponding processing; and the ground data receiving and processing center is used for receiving the marine hydrological data in the form of the short message, decoding, displaying and storing the marine hydrological data, and is also used for sending an instruction to the marine data buoy center. By adopting the device and the method disclosed by the invention, the safety in a marine monitoring data transmission process is ensured, the data transmission distance of the marine hydrological data buoy is expanded, the integrity and the accuracy of the data are ensured, the working time of the buoy is prolonged, the reasonable utilization of energy is realized, and the real-time, efficient, safe and long-distance transmission of the marine monitoring data is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of marine monitoring and satellite communication, and particularly relates to a device for collecting marine hydrological data based on Tiantong satellite and a communication method. Background Art

[0002] Marine hydrological data is important basic data in the fields of marine environmental monitoring, marine resource development, marine disaster warning, etc. Traditional methods for collecting marine hydrological data mainly rely on shipborne surveys, buoy observations, shore-based observations, etc. Satellite communication methods commonly used in buoy observation systems include Iridium communication, Inmarsat communication, Beidou satellite communication, etc. Existing marine hydrological data collection systems based on satellite communication still have some deficiencies:

[0003] 1. High communication cost: Existing systems mostly use foreign satellite communication systems, and the communication fees are expensive, which restricts the popularization and application of the systems.

[0004] 2. Low data transmission rate: The data transmission rate of existing systems is limited, and it is difficult to meet the requirements for collecting high-precision and high-frequency marine hydrological data.

[0005] 3. Low system integration: Existing systems mostly adopt a decentralized architecture, with large equipment volume and high power consumption, which is not conducive to long-term unattended operation.

[0006] Tiantong satellite is a mobile communication satellite independently developed in China, with advantages such as wide coverage, large communication capacity, fast transmission rate, and low cost. Applying Tiantong satellite communication technology to the collection of marine hydrological data can effectively solve the problems existing in existing systems, improve the efficiency and accuracy of marine hydrological data collection, and reduce the system construction and operation costs.

[0007] There is an urgent need for a real-time marine hydrological data collection device and communication method that can transmit data over long distances and operate unattended for a long time to solve the problems of low communication rate, high communication cost, and data security existing in the existing marine data buoy communication system, meet the requirements for deep-sea and long-term synchronous and stable offshore observations, and realize the scientific preservation and use of marine environmental observation data. Summary of the Invention

[0008] Aiming at the problems of low communication rate, high communication cost, and data security existing in the existing marine data buoy communication system, the purpose of the present invention is to overcome the defects of the prior art, and disclose a device for collecting marine hydrological data based on Tiantong satellite and a communication method for marine hydrological data based on Tiantong satellite, so as to realize the real-time, efficient, safe, and long-distance transmission of marine monitoring data.

[0009] In view of this, the present invention provides a device for collecting ocean hydrological data based on Tiantong satellites, comprising: an ocean data buoy center and a ground data receiving and processing center. Among them,

[0010] The ocean data buoy center is used for collecting ocean hydrological data, performing packet processing according to a custom communication format, and sending it to the ground data receiving and processing center in the form of a short message via the Tiantong satellite communication link; it is also used for receiving instructions from the ground data receiving and processing center and performing corresponding processing;

[0011] The ground data receiving and processing center is used for receiving ocean hydrological data in the form of short messages, decoding, displaying, and storing it, and is also used for sending instructions to the ocean data buoy center.

[0012] Preferably, the ocean data buoy center includes: a buoy body, a Tiantong satellite antenna, a Tiantong satellite terminal, a sensor array, a main control board, an acquisition board, a battery, and a cement weight; among them,

[0013] The buoy body is provided with an internal electronic compartment and a top platform;

[0014] The Tiantong satellite antenna is placed on the top platform of the buoy body;

[0015] The Tiantong satellite terminal, the main control board, and the battery are all placed in the internal electronic compartment; among them, the battery uses a lithium battery with an output of 12V and a capacity of 20Ah;

[0016] The acquisition board is placed inside the sensor array;

[0017] The sensor array is placed at the bottom of the buoy body at a position where it can fully contact seawater and avoid direct sunlight interference, and is connected to a watertight connector on the top platform of the buoy body through a cable. The other end of the watertight connector is connected to the main control board in the internal electronic compartment, and the bottom of the sensor array is connected to the cement weight.

[0018] Preferably, the sensor array includes: a CTD (Conductivity, Temperature, Depth) instrument and a thermistor, which are used for collecting temperature, pressure, and conductivity;

[0019] An acquisition unit is arranged on the acquisition board. The acquisition unit includes a temperature acquisition module, a pressure acquisition module, and a conductivity acquisition module, which are respectively used for collecting temperature, pressure, and conductivity data, and performing differential amplification, filtering, and analog-to-digital conversion on the sampled data;

[0020] The acquisition unit further includes an MCU (Microcontroller Unit) module, which is used for receiving the data transmission instruction from the main control board and transmitting the sampled data after analog-to-digital conversion to the main control board via the CAN (Controller Area Network) bus;

[0021] Preferably, a main control unit, a communication unit, a power supply unit, and a storage unit are arranged on the main control board; among them,

[0022] The main control unit is used to send the sampled data processed by the acquisition unit to the communication unit after deep encapsulation, adjust the sampling frequency of the sensor array according to the battery-related parameters provided by the power supply unit, and receive and process the ground instructions forwarded by the communication unit;

[0023] The communication unit is used to transmit the sampled data processed by the acquisition unit to the main control unit, receive the data deep-encapsulated by the main control unit and send it to the ground data receiving and processing center in the form of short messages; it is also used to receive the ground instructions from the ground data receiving and processing center and forward them to the main control unit;

[0024] The power supply unit is used to provide power supply for each component of the ocean data buoy center, and is also used to provide battery-related parameters to the communication unit;

[0025] The storage unit is used to store and back up the sampled data under the control of the main control unit.

[0026] Preferably, the main control unit includes:

[0027] Three UART communication interfaces, one of which is converted to RS232 to connect to the Tiantong satellite terminal, another is converted to RS485 to connect to the power supply unit, and the third is converted to RS232 to connect to the external monitoring PC;

[0028] The SPI communication interface is used to communicate with the storage unit;

[0029] The CAN communication interface is used to communicate with the sensor array;

[0030] Multiple GPIO communication interfaces are used to control the enabling, receiving or sending of the communication unit and the turning on or off of the storage unit respectively.

[0031] Preferably, the power supply unit includes a power management module,

[0032] The power management module is used to obtain various status parameters including the remaining battery power information in real time and send them to the main control unit.

[0033] Preferably, the storage unit includes a FLASH module, which is used to store the array element data collected by the sensor array and realizes turning on or off according to the control of the GPIO communication interface of the main control unit.

[0034] Preferably, the ground data receiving and processing center includes: a satellite communication unit, a data transceiver unit, a data processing unit, and a data display and storage unit, where,

[0035] The satellite communication unit includes a Tiantong satellite antenna and a Tiantong satellite terminal, which are used to receive sampling data in the form of short messages from the ocean data buoy center to the data transceiver unit, and send ground instructions transmitted by the data transceiver unit to the ocean data buoy center;

[0036] The data transceiver unit is used to communicate with the satellite communication unit and the data processing unit through the RS232 serial port;

[0037] The data processing unit is used to perform in-depth decoding processing on the sampling data, restore the original ocean hydrological data according to the custom communication format, and perform calculations, convert the pressure value to the depth value, and convert the conductivity value to the salinity value; it is also used to compare the decoded data according to the number value. When the number values are not continuous, it sends a data retransmission instruction to the ocean data buoy center;

[0038] The data display and storage unit is used to store the received data and display real-time data, historical data, and power warnings.

[0039] Preferably, after the Tiantong satellite terminal of the ground data receiving and processing center is successfully powered on and connected to the network, it sends an instruction Q1 to the ocean data buoy center, including a 2-byte identification header, 1 byte of type, 1 byte of the byte length of the Q1 instruction, 14 bytes of time, 2 bytes of sampling frequency, and 1 byte of CRC check;

[0040] The sampling data D1 sent by the ocean data buoy center to the ground data receiving and processing center includes: a 2-byte identification header, 1 byte of station position identification, 2 bytes of number, 1 byte of data length, 3 bytes of latitude, 4 bytes of longitude, 6 bytes of sampling time, 2 bytes of remaining power value, several bytes of sensor data, and 1 byte of CRC check;

[0041] The ground data receiving and processing center sends a restart power instruction Q2 to the ocean data buoy center, including a 2-byte identification header, 1 byte of the byte length of the Q2 instruction, and 1 byte of CRC check;

[0042] The ground data receiving and processing center sends a data retransmission instruction Q3 with a specified number to the ocean data buoy center, including a 2-byte identification header, 1 byte of type, 1 byte of the byte length of the Q3 instruction, 2 bytes of number, and 1 byte of CRC check.

[0043] On the other hand, the present invention proposes a communication method for ocean hydrological data based on Tiantong satellite, which is implemented based on the above device and includes:

[0044] Step 1: After the Tiantong satellite terminal of the ground data receiving and processing center is successfully powered on and connected to the network, it sends an instruction Q1 to the ocean data buoy center in the form of a short message through Tiantong satellite communication to set the initial time and sampling time interval of the buoy center;

[0045] Step 2: After the ocean data buoy center receives command Q1 or the power restart command Q2, power on the sensor array, set the time and sampling time interval of the buoy center, and collect ocean hydrological data;

[0046] Step 3: The ocean data buoy center saves the collected array element data, combines it with the remaining battery level value for data packetization, and sends the sampled data D1 to the ground data receiving and processing center in the form of a short message through the Tiantong satellite communication; when receiving the data retransmission command Q3 with a specified number, send the sampled data D2 with the specified number to the ground data receiving and processing center;

[0047] Step 4: If the ground data receiving and processing center does not receive the sampled data after exceeding the set waiting duration, send the power restart command Q2; otherwise, decode the received sampled data D1, restore the original ocean hydrological data according to the custom communication format, and when there is a missing data number, send the data retransmission command Q3 with the missing number information; otherwise, further judge whether the remaining battery level value is lower than the set threshold. If judged to be yes, reset the sampling frequency, construct a new command Q1 and send it;

[0048] Step 5: Save and display the ocean hydrological data restored from the sampled data D1 or D2;

[0049] Step 6: Repeat Steps 1 to 5 at a preset period.

[0050] Compared with the prior art, the advantages of the present invention are as follows:

[0051] The present invention selects the Tiantong satellite communication system, which ensures the security of the ocean monitoring data transmission process and expands the data transmission distance of the ocean hydrological data buoy. The designed ocean hydrological data acquisition and forwarding device of the present invention is equipped with a FLASH storage module to store and back up the data. During the data transmission process, when detecting data packet loss, the FLASH module can automatically start the retransmission mechanism to ensure the integrity and accuracy of the data. The designed ocean hydrological data acquisition and forwarding device of the present invention also has a battery power monitoring function, which can adaptively and dynamically adjust the sampling frequency of the sensor nodes, reduce unnecessary data acquisition, thereby reducing power consumption, extending the working time of the buoy, and realizing the rational utilization of energy. The designed communication method of the present invention uses a custom data acquisition protocol format and instruction format to achieve efficient interaction between the ocean hydrological data buoy and the ground data processing center, and realizes the real-time, efficient, secure, and long-distance transmission of ocean monitoring data. Description of the Drawings

[0052] Figure 1It is a schematic diagram of the device composition of the ocean hydrological data acquisition device based on the Tiantong satellite of the present invention;

[0053] Figure 2 It is a schematic diagram of the composition of the central functional modules of the ocean data buoy;

[0054] Figure 3 It is a schematic diagram of the composition of the central functional modules of the ground data processing center;

[0055] Figure 4 It is a flowchart of the communication method for ocean hydrological data based on the Tiantong satellite. Specific implementation mode

[0056] The present invention designs an ocean hydrological data acquisition and forwarding device based on the Tiantong satellite, mainly including the ocean data buoy center and the ground data receiving and processing center. The ocean data buoy center automatically forwards the collected ocean hydrological data to the ground data receiving and processing center through the Tiantong satellite communication link according to the communication method designed by the present invention.

[0057] Among them, the ocean data buoy center is responsible for collecting ocean hydrological data, performing packet processing on the data according to the communication method designed by the present invention, and finally sending it to the ground Tiantong satellite terminal in the form of a short message. The ocean data buoy center includes a main control unit, a communication unit, a collection unit, a power supply unit, and a storage unit.

[0058] The main control unit includes three UART communication interfaces, three SPI communication interfaces, one CAN communication interface, and a rich set of GPIO pins. One of the three UART interfaces is converted to RS232 to connect to the Tiantong satellite terminal in the communication unit, another is converted to RS485 to connect to the battery management module in the power supply unit, and the last one is converted to RS232 to connect to the external monitoring PC. One of the SPI communication ports of the main control unit is used to communicate with the FLASH chip of the storage module to store and read data; the main control unit communicates with the collection unit in the sensor array through the CAN communication port to obtain array element data.

[0059] The communication unit includes a Tiantong satellite module, an RS232 communication module, an RS485 communication module, and a CAN communication module. The Tiantong satellite communication module includes an antenna and a data terminal. As the communication hub between the ocean data buoy unit and the ground data receiving and processing center, the Tiantong satellite communication module shoulders the heavy responsibility of coordinating data transmission. It receives data from the main control unit, and in strict accordance with the Tiantong satellite communication protocol, deeply encapsulates the data, adds necessary check codes, address information, etc., and sends the data to the ground Tiantong satellite terminal in the form of short messages to ensure the accuracy and reliability of the data during transmission. At the same time, this unit is also responsible for receiving instructions issued by the ground data receiving and processing center. The main control unit performs relevant operations according to the content of the instruction information, including powering on / off the sensor group or resending the collected data, etc. The RS232 communication module mainly communicates with the Tiantong satellite terminal to realize data transmission and reception with the Tiantong satellite terminal, and is also responsible for powering the Tiantong satellite terminal. The main control unit controls the enabling or disabling of the RS232 communication module through the GPIO port. When data needs to be sent, the RS232 communication module is enabled; when data is not being sent, the RS232 communication module is turned off to save power. The RS485 communication module is mainly responsible for communicating with the battery management module in the power supply module to obtain relevant parameters of the battery, such as the remaining power, etc. The main control unit controls the transmit enable and receive enable of the RS485 communication module through the GPIO port, and controls the transmission and reception of the interface circuit. The CAN communication module is mainly responsible for communicating with the acquisition array to obtain the data collected by each element on the acquisition array, and is also responsible for powering the acquisition array.

[0060] The acquisition unit includes a sensor array, a temperature acquisition module, a pressure acquisition module, a conductivity acquisition module, an analog-to-digital conversion module, and an MCU module. The sensor array includes a CTD (Conductivity Temperature Depth) instrument and a thermistor, and can collect three types of data: temperature, pressure, and conductivity. The temperature acquisition module includes a temperature sensor, a differential amplifier, and an RC passive filter. It is responsible for receiving the temperature data collected by the sensor array and performing differential amplification and passive filtering on the temperature data. The pressure acquisition module includes a pressure sensor, an operational amplifier, a differential amplifier, and an RC passive filter. It is responsible for receiving the pressure data collected by the sensor array and performing operational amplification, differential amplification, and passive filtering on the pressure data. The conductivity acquisition module includes a conductivity sensor, an operational amplifier, and a differential amplifier. It is responsible for receiving the conductivity data collected by the sensor array and performing operational amplification and differential amplification on the conductivity data. The analog-to-digital conversion module is responsible for converting the data collected by the sensor array from an analog signal to a digital signal. The MCU module is responsible for controlling the power supply of the acquisition elements, controlling the analog-to-digital conversion module to convert the collected data, and sending the data back to the main control unit after receiving the data return instruction from the main control unit.

[0061] The power supply unit includes a device battery and a power management unit, which is responsible for step - down of the voltage output from the battery pack in two stages. Starting from 12V, after two - stage step - down, it first drops to 5V and then to 3.3V to provide stable power supply for each control module and the sensor group. The device battery is a lithium battery with an output of 12V and a capacity of 20Ah. The power management module obtains various state parameters of the battery in real - time through RS232 communication, especially the remaining battery power information, so as to adjust the system power consumption in a timely manner and ensure the stable operation of the system under different power conditions.

[0062] The storage unit includes a FLASH module. The FLASH is responsible for storing the data collected by the sensor array and can provide a storage capacity of 2GB. The main control unit controls the opening or closing of the FLASH module through the GPIO port, and sets the FLASH to the off mode when data collection is not in progress to reduce power consumption.

[0063] The ground data receiving and processing center is responsible for receiving the ocean hydrological data sent by the ocean data buoy center, decoding, displaying and storing the data. It can also send relevant instructions to the ocean data buoy center, including instructions to power on / off the sensor group, adjust the sampling parameters of the acquisition array or resend the acquisition data, etc. It includes a satellite communication unit, a data transceiver unit, a data processing unit, a data display unit and a data storage unit.

[0064] The satellite communication unit includes a Tiantong satellite antenna and a Tiantong satellite terminal, which is responsible for receiving data from the ocean data buoy center and sending instructions to the ocean data buoy center.

[0065] The data transceiver unit includes RS232 serial port settings, data reception and instruction sending. It is responsible for setting the RS232 communication serial port parameters, receiving data from the ground Tiantong satellite terminal through the RS232 serial port and sending instructions to the ocean data buoy center.

[0066] The data processing unit includes data decoding and data number comparison. The data decoding module is responsible for deeply decoding the data received through RS232. According to the data communication protocol, it restores the original ocean hydrological data, and according to the empirical formula, converts the pressure value into a depth value and the conductivity value into a salinity value. The data number comparison is responsible for comparing the number values of the decoded data to determine whether there is a discontinuity in the numbers. If the numbers are not continuous, it means that there is a packet loss, and a data resend instruction will be sent to the ocean data buoy center.

[0067] The data display unit includes real-time data display, historical data display, and power warning. The real-time data display module is responsible for displaying the data that has not been processed and is received in real-time via RS232. The historical data display is responsible for presenting the processed data in intuitive visual forms such as charts and curves, facilitating users to intuitively understand the changing trends of the marine environment. The power warning module, based on the remaining power, timely sends instructions to the marine data buoy center to dynamically adjust the sampling frequency of the sensor nodes to achieve reasonable utilization of energy.

[0068] The present invention also designs a communication method for a marine data acquisition and forwarding device based on Tiantong satellite communication. Based on the above acquisition and forwarding device, the marine data in the target area is collected, and data transceiver with the ground data receiving and processing center is realized via the Tiantong satellite. The steps include:

[0069] Step P1: Install corresponding satellite cards on the Tiantong satellite terminals of the marine data buoy center and the ground data receiving and processing center respectively. After connecting the power supply and the RS232 serial port line, power on and wait for the LED light indicating successful network access of the Tiantong satellite terminal to turn on.

[0070] Step P2: After the Tiantong satellite terminal of the ground data receiving and processing center is successfully powered on and connected to the network, send an instruction Q1 to the marine data buoy center via Tiantong satellite communication in the form of a short message to set the initial time and sampling time interval of the buoy center.

[0071] Step P3: After the main control unit of the marine data buoy center receives the instruction Q1, power on the acquisition array element and set the time of the buoy center and the sampling time interval of the array element. After the setting is completed, the acquisition array element starts to collect marine hydrological data.

[0072] Step P4: The acquisition array element of the marine data buoy center will automatically save the collected marine hydrological data into the FLASH module. The main control unit will read the data in the FLASH module, perform data packetization, and then send the sampling data D1 to the ground data receiving and processing center via Tiantong satellite communication in the form of a short message.

[0073] Step P5: After sending the instruction Q1 in Step 2, the ground data receiving and processing center will wait for the arrival of the sampling data. If the sampling data has not been received after exceeding the set waiting time duration, the ground data receiving and processing center will send an instruction Q2 to restart the power supply to the marine data buoy center. According to the restart power supply instruction Q2, the marine data buoy center will power on the sensor group and the Tiantong satellite terminal again. After the power-on is completed, repeat Steps P1 to P5. If the ground data receiving and processing center receives the sampling data D1 within the set waiting time duration, it will enter Step P6.

[0074] Step P6: The ground data receiving and processing center decodes the received sampling data D1, extracts the original data collected by the sensors, and determines whether the data number is missing. If there is a missing data number, it sends an instruction Q3 to the ocean data buoy center to resend the data with the specified number. This ensures the integrity of data reception and reduces the data packet loss rate. The main control module of the ocean data buoy center will repeat steps P4 - P6 according to the received instruction Q3. At this time, the sampling data D2 with the specified number is sent in step P4. If the data numbers are in normal sequence, it proceeds to step P7.

[0075] Step P7: The ground data receiving and processing center determines whether the battery power value is lower than the set threshold based on the data decoded in step P6. If the battery power value is lower than the set threshold, it sends an instruction Q1 to the ocean data buoy center. The ocean data buoy center will automatically adjust the sampling frequency of the sensor nodes according to instruction Q1, reduce unnecessary data collection, thereby reducing power consumption and extending the working time of the buoy, and repeat steps P3 - P7. When the power is higher than the set threshold, the sensor nodes collect data at the normal sampling frequency to ensure the continuity and accuracy of the data, and proceed to step P8.

[0076] Step P8: The ground data receiving and processing center saves and graphically displays the received sensor sampling data.

[0077] The above steps are a complete cycle of the ocean hydrological data acquisition, forwarding, and processing process based on Tiantong satellite communication. The system repeats the cyclic data acquisition, forwarding, and processing process of steps P1 - P8 at a preset cycle or proceeds to step P9.

[0078] Step P9: The upper computer software system of the ground data receiving and processing center is shut down and the Tiantong satellite terminal is powered off. The ocean data buoy center interrupts the power supply of the Tiantong satellite terminal and the power supply of the acquisition array.

[0079] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0080] Embodiment 1

[0081] As Figure 1 shown, an acquisition device for ocean hydrological data based on Tiantong satellite provided by Embodiment 1 of the present invention includes an ocean data buoy center and a ground data receiving and processing center, which communicate with each other through Tiantong satellite communication and realize data transmission and reception between the two in the form of short messages.

[0082] The hardware equipment of the Marine Data Buoy Center includes a buoy body, a Tiantong satellite antenna, a Tiantong satellite terminal, a sensor array, a main control board, an acquisition board, a battery, and a cement weight. The buoy body is equipped with an internal electronics compartment, a top platform, a recovery ring, indicator lights, and an antenna protection cover. The Tiantong satellite antenna is placed on the top platform of the buoy, inside the antenna protection cover. The sensor array is placed at the bottom of the buoy body in a position where it can fully contact seawater and avoid direct sunlight interference, ensuring that it can accurately collect real-time marine hydrological data. The sensor array is connected to a watertight connector at the top of the buoy body through a cable, and the other end of the watertight connector is connected to the main control board in the internal electronics compartment. The bottom of the sensor array is connected to a cement weight, enabling the sensor array to be relatively stably fixed in a specified position and continuously and accurately measure data. The main control board, Tiantong satellite terminal, and battery are placed in the internal electronics compartment of the buoy. The acquisition board is placed inside the sensor array.

[0083] The hardware equipment of the Ground Data Reception and Processing Center includes a Tiantong satellite antenna, a Tiantong satellite terminal, a display, and a server. The Tiantong satellite antenna and the Tiantong satellite terminal are connected through Tiantong data lines and GPS data lines, and a 12V / 24V DC power supply is used to power the Tiantong terminal. The server is connected to the Tiantong terminal through an RS232 serial port line to achieve the sending and receiving of serial data.

[0084] The functional modules of the Marine Data Buoy Center include a main control unit, a communication unit, an acquisition unit, a power supply unit, and a storage unit. For the schematic diagram of the composition of the functional modules of the Marine Data Buoy Center, refer to Figure 2 ... Among them, the main control unit, communication unit, power supply unit, and storage unit are located on the main control board, and the acquisition unit is located on the acquisition board. The main control board and the acquisition board communicate through the CAN bus.

[0085] The main control unit uses an STM32L433 chip, which includes three UART communication interfaces, three SPI communication interfaces, one CAN communication interface, and a rich set of GPIO pins. One of the three UART interfaces is converted to RS232 to connect to the buoy Tiantong satellite terminal, another is converted to RS485 to connect to the battery management module in the power supply unit, and the last one is converted to RS232 to connect to an external monitoring PC. One of the SPI communication ports of the main control unit is used to communicate with the FLASH chip in the storage module to store and read data; the main control unit communicates with the array in the acquisition unit through the CAN communication port to obtain array element data.

[0086] The communication unit includes a Tiantong satellite module, an RS232 communication module, an RS485 communication module, and a CAN communication module. The Tiantong satellite communication module includes an antenna and a data terminal, and the Tiantong satellite antenna and the data terminal are connected through Tiantong data lines and GPS data lines. The RS232 communication module uses the MAX3222 chip and is connected to the main control unit to realize data transceiver with the Tiantong satellite terminal and is also responsible for supplying power to the Tiantong satellite terminal. The RS485 communication module uses the SN65HVD3082 chip and is connected to the battery management module in the power supply module to obtain relevant parameters of the battery, such as the remaining power, etc. The CAN communication module uses the SN65HVD230 chip, is connected to the acquisition unit, obtains the acquisition array data, and supplies power to the acquisition array.

[0087] The acquisition unit includes a temperature acquisition module, a pressure acquisition module, a conductivity acquisition module, an analog-to-digital conversion module, and an MCU module. The sensor array includes a CTD (Conductivity Temperature Depth) instrument and a thermistor, and can acquire three types of data: temperature, pressure, and conductivity. The temperature acquisition module, the pressure acquisition module, and the conductivity acquisition module perform differential amplification, filtering, and analog-to-digital conversion on the acquired data, and transmit the data back to the main control unit through the CAN bus.

[0088] The power supply unit includes a device battery and a power management unit, which is responsible for step-down voltage of the voltage output by the battery pack in two stages. The device battery uses a lithium battery with an output of 12V and 20Ah. The power management module obtains various state parameters of the battery in real time through RS232 communication, especially the battery remaining power information, so as to adjust the system power consumption in time and ensure the stable operation of the system under different power conditions.

[0089] The storage unit includes a FLASH module. The FLASH is responsible for storing the data acquired by the sensor array and can provide a storage capacity of 2GB. The main control unit controls the opening or closing of the FLASH module through the GPIO port, and sets the FLASH to the off mode when data acquisition is not performed to reduce power consumption.

[0090] The functional modules of the ground data receiving and processing center include a satellite communication unit, a data transceiver unit, a data processing unit, a data display unit, and a data storage unit. The schematic diagram of the composition of the functional modules of the ground data receiving and processing center refers to Figure 3 .

[0091] The Tiantong satellite antenna and the Tiantong satellite terminal are connected through Tiantong data lines and GPS data lines. The data transceiver unit obtains RS232 data, and then the data is transmitted to the data processing unit to decode the data and restore the original sampled data. The data processing and analysis unit transmits the processed results to the display and warning unit, and the display and warning unit displays the ocean environment data and its change trends in the form of intuitive charts (such as line charts, bar charts, etc.).

[0092] It should be noted that in the embodiments of the above system, the included modules are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of the functional modules are only for the convenience of mutual distinction and do not limit the protection scope of the present invention.

[0093] Embodiment 2

[0094] As Figure 4 shown, Embodiment 2 of the present invention provides a communication method for ocean data based on Tiantong satellite communication, which is implemented based on the ocean data acquisition and forwarding device based on Tiantong satellite communication in Embodiment 1, and completes the acquisition of ocean data in the target area, and realizes data transceiver with the ground data receiving and processing center through Tiantong satellite. The specific steps are as follows:

[0095] Step P1: Install corresponding satellite cards on the Tiantong satellite terminals of the ocean data buoy center and the ground data receiving and processing center respectively. After connecting the power supply and the RS232 serial port line, turn on the power supply and wait for the LED light indicating successful network access of the Tiantong satellite terminal to light up.

[0096] Step P2: After the Tiantong satellite terminal of the ground data receiving and processing center is powered on and successfully accesses the network, send an instruction Q1 to the ocean data buoy center in the form of a short message through Tiantong satellite communication to set the initial time and sampling time interval of the buoy center. The protocol format of instruction Q1 is as shown in Table 1 below, where the storage method of multi-byte data in the memory is the little-endian method (the low byte is at the low address);

[0097] Table 1

[0098]

[0099] Each frame of message of instruction Q1 starts with two "@" as the start flag. The type sub-field is set to the symbol "T", indicating that this message is instruction Q1. The length information field is the number of bytes of each frame of instruction Q1. The time information field is the time value to be set, and the format is a 4-byte year value, a 2-byte month value, a 2-byte date value, a 2-byte hour value, a 2-byte minute value, and a 2-byte second value. When the time value is less than 2 bytes, 0 needs to be filled in front. The sampling frequency field is a 2-byte frequency value. The check field is the CRC check value of all bytes of instruction Q1.

[0100] Step P3: After the main control unit of the ocean data buoy center receives instruction Q1, power on the acquisition array element, and set the time of the buoy center and the sampling time interval of the array element. After the setting is completed, the acquisition array element starts to collect ocean hydrological data.

[0101] Step P4: The acquisition array elements at the center of the ocean data buoy will automatically save the collected ocean hydrological data to the FLASH module. The main control unit will read the data in the FLASH module, perform data packetization, and then send the sampling data D1 to the ground data receiving and processing center in the form of a short message via the Tiantong satellite communication. The protocol format of the sampling data D1 is shown in Table 2.

[0102] Table 2

[0103]

[0104] The protocol format of the sampling data D1 includes three parts: a message header, a message body, and a message tail. The message header includes an identification header, a station identification, a number, and a length. In one embodiment, the identification header is "##". The station identification is "1 to 256", which sets a unique station identification for the buoy site. The number is the number of the sampling data frame, and the value range is "1 to 65536". The length value is the total number of bytes of one frame of the sampling data D1. The message body includes longitude, latitude, time, power, and sensor data. The longitude and latitude data are the data collected by the GPS module of the Tiantong terminal. The time is set as the sampling time. The power is set as the remaining battery power value. The sensor data is dynamically adjusted according to the number of sensor nodes, and the data between multiple sensors is connected in sequence. The check field is set as the CRC check value of all bytes of one frame of the sampling data D1. The length range of the sampling data D1 data frame is 22 to 140 bytes, and the change in the data frame length depends on the change in the number of sensors.

[0105] Step P5: After the ground data receiving and processing center sends the instruction Q1 in Step 2, it will wait for the arrival of the sampling data. If the sampling data has not been received after exceeding the set waiting time duration, the ground data receiving and processing center will send an instruction Q2 to restart the power supply to the ocean data buoy center. According to the restart power supply instruction Q2, the ocean data buoy center will power on the sensor group and the Tiantong satellite terminal again. After the power-on is completed, Steps P1 to P5 will be repeated. If the ground data receiving and processing center receives the sampling data D1 within the set waiting time duration, it will enter Step P6.

[0106] Table 3

[0107]

[0108] The protocol format of the instruction Q2 includes two parts: a message header and a message tail. The message header includes an identification header, a type, and a length. In one embodiment, the identification header is "@@", the type is set as "R", the length value is "5", and the check field is the CRC check value of all bytes of the instruction Q2.

[0109] Step P6: The ground data reception and processing center decodes the received sampling data D1, extracts the original data collected by the sensors, and determines whether the data number is missing. If there is a missing data number, it sends a command Q3 to the ocean data buoy center to resend the data with the specified number, ensuring the integrity of data reception and reducing the data packet loss rate. The main control module of the ocean data buoy center will repeat steps P4 - P6 according to the received command Q3. At this time, the sampling data D2 sent in step P4 is the sampling data with the specified number. The protocol format of the sampling data D2 is the same as that of the sampling data D1, as shown in Table 2. The protocol format of the command Q3 is shown in Table 4.

[0110] Table 4

[0111]

[0112] The protocol format of the command Q3 includes three parts: a message header, a message body, and a message tail. The message header includes an identification header, a type, and a length. In one embodiment, the identification header is “@@”, the type is set to “T”, and the length value is “7”. The number field is set to the number value in the sampling data frame D1 that needs to be resent. The check field is the CRC check value of all bytes of the command Q3.

[0113] Step P7: The ground data reception and processing center determines whether the battery power value is lower than the set threshold based on the data decoded in step P6. If the battery power value is lower than the set threshold, it sends a command Q1 to the ocean data buoy center. The ocean data buoy center will automatically adjust the sampling frequency of the sensor nodes according to the command Q1, reduce unnecessary data collection, thereby reducing power consumption and extending the working time of the buoy, and repeat steps P3 - P7. When the power is higher than the set threshold, the sensor nodes perform data collection at the normal sampling frequency to ensure the continuity and accuracy of the data, and enter step P8.

[0114] Step P8: The ground data reception and processing center saves and graphically displays the received sensor sampling data.

[0115] The above steps are a complete cycle of the ocean hydrological data acquisition, forwarding, and processing process based on Tian Tong satellite communication. The system repeats the cyclic data acquisition, forwarding, and processing process of steps P1 - P8 at a preset cycle or enters step P9.

[0116] Step P9: The upper computer software system of the ground data reception and processing center is shut down and the Tian Tong satellite terminal is powered off. The ocean data buoy center interrupts the power supply of the Tian Tong satellite terminal and the power supply of the acquisition array.

[0117] In summary, the present invention provides an acquisition and forwarding device and a communication method for ocean hydrological data based on Tiantong satellites, which can achieve real-time and efficient transmission of ocean monitoring data, and realize dual backup of the buoy end and the ground end of ocean detection data. Through the invented communication method, sampling data with different numbers of acquisition array elements can be dynamically sent, and packet loss retransmission of data can also be realized to ensure the integrity and accuracy of data. The ocean hydrological data acquisition and forwarding device designed by the present invention also has a battery power monitoring function, which can adaptively and dynamically adjust the sampling frequency of sensor nodes, reduce unnecessary data acquisition, thereby reducing power consumption, extending the working time of the buoy, and realizing reasonable utilization of energy.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A device for collecting ocean hydrological data based on Tiantong satellite, characterized in that: include: Oceanographic data buoy center and ground data receiving and processing center, including: The ocean data buoy center is used to collect ocean hydrological data, package it according to a custom communication format, and send it to the ground data receiving and processing center in the form of short messages via the Tiantong satellite communication link; it is also used to receive instructions from the ground data receiving and processing center and perform corresponding processing; The ground data receiving and processing center is used to receive the ocean hydrological data in the form of short messages, decode, display and store them, and also to send instructions to the ocean data buoy center.

2. The ocean hydrological data collection device based on Tiantong satellite according to claim 1 is characterized in that: The ocean data buoy center includes: a buoy body, a Tiantong satellite antenna, a Tiantong satellite terminal, a sensor array, a main control board, a collection board, a battery and a cement weight; wherein, The buoy body is provided with an internal electronic compartment and a top platform; The Tiantong satellite antenna is placed on the top platform of the buoy body; The Tiantong satellite terminal, main control board and battery are all placed in the internal electronic compartment; the battery is a 12V output, 20Ah lithium battery; The acquisition board is placed in the sensor array; The sensor array is placed at the bottom of the buoy body where it can fully contact the seawater and avoid interference from direct sunlight. It is connected to a watertight connector on the top platform of the buoy body via a cable. The other end of the watertight connector is connected to the main control board in the internal electronic compartment. The bottom of the sensor array is connected to a cement weight.

3. The ocean hydrological data collection device based on Tiantong satellite according to claim 2 is characterized in that: The sensor array includes: a temperature-salinity-depth instrument and a temperature-depth instrument, which are used to collect temperature, pressure and conductivity; The acquisition board is provided with an acquisition unit, which includes a temperature acquisition module, a pressure acquisition module and a conductivity acquisition module, which are respectively used to acquire temperature, pressure and conductivity data, and perform differential amplification, filtering and analog-to-digital conversion on the sampled data; The acquisition unit also includes an MCU module, which is used to receive data return instructions from the main control board and return the sampled data after analog-to-digital conversion to the main control board through the CAN bus.

4. The ocean hydrological data collection device based on Tiantong satellite according to claim 3 is characterized in that: The main control board is provided with a main control unit, a communication unit, a power supply unit and a storage unit; wherein, The main control unit is used to send the sampled data processed by the acquisition unit to the communication unit after deep packaging, to adjust the sampling frequency of the sensor array according to the battery-related parameters provided by the power supply unit, and to receive and process the ground instructions forwarded by the communication unit; The communication unit is used to transmit the sampled data processed by the acquisition unit to the main control unit, to receive the deeply packaged data from the main control unit and send it to the ground data receiving and processing center in the form of short messages; and to receive ground instructions from the ground data receiving and processing center and forward them to the main control unit; The power supply unit is used to provide power supply to various components of the ocean data buoy center and also to provide battery-related parameters to the communication unit; The storage unit is used to store and back up the sampled data under the control of the main control unit.

5. The ocean hydrological data collection device based on Tiantong satellite according to claim 4 is characterized in that: The main control unit comprises: Three-way UART communication interface, one of which is converted to RS232 to connect to Tiantong satellite terminal, another is converted to RS485 to connect to power supply unit, and the third is converted to RS232 to connect to external monitoring PC; SPI communication interface, used to communicate with the storage unit; CAN communication interface, used to communicate with the sensor array; Multiple GPIO communication interfaces are used to control the communication unit enable, receiving or sending, and the opening or closing of the storage unit.

6. The ocean hydrological data collection device based on Tiantong satellite according to claim 5 is characterized in that: The power supply unit includes: a power management module, which is used to obtain various status parameters including battery remaining power information in real time and send them to the main control unit.

7. The ocean hydrological data collection device based on Tiantong satellite according to claim 3 is characterized in that: The storage unit includes: a FLASH module, which is used to store array data collected by the sensor array and is turned on or off according to the control of the GPIO communication interface of the main control unit.

8. The ocean hydrological data collection device based on Tiantong satellite according to claim 1 is characterized in that: The ground data receiving and processing center includes: a satellite communication unit, a data transceiver unit, a data processing unit, and a data display and storage unit, wherein: The satellite communication unit includes a Tiantong satellite antenna and a Tiantong satellite terminal, which are used to receive the sampled data in the form of short messages from the ocean data buoy center to the data transceiver unit, and send the ground instructions transmitted by the data transceiver unit to the ocean data buoy center; The data transceiver unit is used to communicate with the satellite communication unit and the data processing unit through the RS232 serial port; The data processing unit is used to perform deep decoding processing on the sampled data, restore the original ocean hydrological data according to the customized communication format, and perform calculations to convert the pressure value into the depth value and the conductivity value into the salinity value; it is also used to compare the decoded data according to the number value, and send a data retransmission instruction to the ocean data buoy center when the number value is discontinuous; The data display storage unit is used to store the received data and display the real-time data, historical data and power warning.

9. The ocean hydrological data collection device based on Tiantong satellite according to claim 8 is characterized in that: After the Tiantong satellite terminal of the ground data receiving and processing center is powered on and connected to the network successfully, it sends a command Q1 to the ocean data buoy center, including a 2-byte identification header, a 1-byte type, a 1-byte byte length of the Q1 command, a 14-byte time, a 2-byte sampling frequency and a 1-byte CRC check; The sampling data D1 sent by the ocean data buoy center to the ground data receiving and processing center includes: a 2-byte header, a 1-byte station identifier, a 2-byte number, a 1-byte data length, a 3-byte latitude, a 4-byte longitude, a 6-byte sampling time, a 2-byte remaining power value, several bytes of sensor data and a 1-byte CRC checksum. The ground data receiving and processing center sends a power restart instruction Q2 to the ocean data buoy center, including a 2-byte identification header, a 1-byte byte length of the Q2 instruction, and a 1-byte CRC check. The ground data receiving and processing center sends a data retransmission instruction Q3 with a specified number to the ocean data buoy center, including a 2-byte identification header, a 1-byte type, a 1-byte byte length of the Q3 instruction, a 2-byte number and a 1-byte CRC check.

10. A method for communicating ocean hydrological data based on Tiantong satellite, implemented based on the device of claim 9, comprising: Step 1: After the Tiantong satellite terminal of the ground data receiving and processing center is powered on and connected to the network successfully, it sends instruction Q1 to the ocean data buoy center via Tiantong satellite communication in the form of a short message to set the initial time and sampling time interval of the buoy center; Step 2: After receiving the instruction Q1 or the power restart instruction Q2, the ocean data buoy center powers on the sensor array, sets the time and sampling time interval of the buoy center, and collects ocean hydrological data; Step 3: The ocean data buoy center saves the collected array data, and packages the data in combination with the remaining power value, and sends the sampled data D1 to the ground data receiving and processing center in the form of a short message via the Tiantong satellite communication; when receiving the data resend instruction Q3 with a specified number, the sampled data D2 with a specified number is sent to the ground data receiving and processing center; Step 4: If the ground data receiving and processing center fails to receive the sampled data within the set waiting time, it sends a restart power instruction Q2. Otherwise, it decodes the received sampled data D1 and restores the original ocean hydrological data according to the customized communication format. If the data number is missing, it sends a data retransmission instruction Q3 with the missing number information. Otherwise, it further determines whether the remaining power value is lower than the set threshold. If it is, it resets the sampling frequency, builds a new instruction Q1 and sends it. Step 5: Save and display the ocean hydrological data restored from the sampling data D1 or D2; Step 6: Repeat steps 1 to 5 at a preset cycle.

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