Shipborne transceiver for underwater acoustic positioning system and underwater acoustic positioning system

Abstract

The present invention discloses a shipboard transceiver and a hydroacoustic positioning system for use in a hydroacoustic positioning system, and relates to the field of marine oil exploration. The shipboard transceiver comprises a processing unit, a receiving unit, a transmitting unit, and a transceiver device. The processing unit comprises a processor and its peripheral circuits. The receiving unit comprises a function selection module, a receiver, a frequency selection module, and an analog-to-digital conversion circuit. The function selection module is used to change the working environment of the shipboard transceiver and receive transponder signals through the transceiver device. The frequency selection module is used to perform frequency selection processing on the received signal when the received signal is a narrowband signal. The transmitting unit is used to drive the transceiver device to transmit signals. The transceiver device comprises a wireless coil for use in an above-water environment and a transducer for use in an underwater environment. The present invention utilizes electromagnetic induction and hydroacoustic communication methods and corresponding hardware circuits to enable the shipboard transceiver to effectively meet the interaction requirements with the transponder in various usage scenarios.

Description

Technical Field

[0001] The present invention relates to the field of marine oil exploration, and in particular to a shipborne transceiver used in an underwater acoustic positioning system and the underwater acoustic positioning system. Background Art

[0002] In existing marine oil exploration technologies, shipboard transceivers are usually installed on exploration ships, drilling platforms, etc., and mainly provide ranging and positioning functions, while the transponder, as the response end, is usually deployed at a fixed point on the seabed or installed on the target that needs to be positioned. The shipboard transceiver transmits a specifically coded acoustic pulse signal. After the transponder receives the signal from the shipboard transceiver, it transmits a specific acoustic response signal as a response signal. The shipboard transceiver calculates the distance between the shipboard transceiver and the transponder, the position of the transponder, etc. based on the time interval between its own transmission signal and the reception of the response signal, thereby realizing the ranging and positioning functions. In actual applications, the shipboard transceiver and the transponder need to exchange information in different usage scenarios, such as interaction in a water environment and interaction in an underwater environment. However, the existing interaction method between the shipboard transceiver and the transponder is difficult to meet the requirements of different usage scenarios. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed to provide a shipborne transceiver used in a hydroacoustic positioning system and a hydroacoustic positioning system that overcomes the above problems or at least partially solves the above problems.

[0004] According to one aspect of an embodiment of the present application, a shipborne transceiver for use in an underwater acoustic positioning system is provided, the shipborne transceiver comprising: a processing unit, a receiving unit, a transmitting unit, and a transceiver device;

[0005] The processing unit includes a processor and its peripheral circuits; the processor is used for converting analog signals into digital signals; the peripheral circuits include an operation panel circuit, a power supply circuit, a battery charge detection circuit, and a battery charging protection circuit;

[0006] The receiving unit includes a function selection module, a receiver, a frequency selection module, and an analog-to-digital conversion circuit; the function selection module is used to change the working environment of the shipboard transceiver and receive the transponder signal through the transceiver; the receiver is used to pre-process the received signal and select the received signal to be sent to the frequency selection module or the analog-to-digital conversion circuit according to the signal form; the frequency selection module is used to perform frequency selection processing on the received signal when the received signal is a narrowband signal;

[0007] The transmitting unit is used to drive the transceiver device to transmit signals to communicate with the transponder;

[0008] The transceiver equipment includes a wireless coil for use in an above-water environment and a transducer for use in an underwater environment.

[0009] Furthermore, the operation panel circuit includes a button control circuit, a display screen control circuit and a buzzer drive circuit;

[0010] The button control circuit includes a knob matrix circuit and a debounce reset switch circuit;

[0011] The display screen control circuit is used to drive the display so that the display shows the real-time status information of the shipborne transceiver;

[0012] The buzzer driving circuit is used to drive the buzzer to sound when the shipborne transceiver successfully receives feedback from the transponder after sending a command.

[0013] Furthermore, the receiver includes a signal filtering and amplifying circuit and a signal shaping circuit;

[0014] The signal filtering and amplifying circuit includes a differential amplifier circuit and a fourth-order Butterworth filter;

[0015] The signal shaping circuit uses a voltage comparator to convert the sine wave into a corresponding square wave.

[0016] Furthermore, the frequency selection module includes a narrowband bandpass filter constructed by multiple groups of capacitors and inductors.

[0017] Furthermore, the transmitting unit includes a wireless coil communication circuit, a transducer communication circuit and a digital-to-analog conversion circuit;

[0018] The wireless coil communication circuit includes a linear power amplifier circuit and a filter; the linear power amplifier circuit is used to drive the wireless coil to transmit signals;

[0019] The transducer communication circuit includes a class D power amplifier circuit and a transmitting drive circuit; the class D power amplifier circuit is used to drive the transducer to transmit signals; the transmitting drive circuit is used to perform current enhancement and dead zone processing on the transmitting signals.

[0020] Furthermore, the processor is connected to the output end of the frequency selection module and detects whether the narrowband signal arrives through the level state of the GPIO interface.

[0021] According to another aspect of an embodiment of the present application, there is provided an underwater acoustic positioning system, characterized in that it includes a command protocol design module, a signal processing module, and the shipborne transceiver used in the underwater acoustic positioning system as described above;

[0022] The command protocol design module is used to design protocols for downlink commands from the shipborne transceiver to the transponder, and uplink commands from the transponder to the shipborne transceiver. The transponders are divided into multiple groups, and each group is divided into multiple channels to form multiple transponder combinations.

[0023] The signal processing module is used to process the received signal using a preset algorithm.

[0024] Furthermore, the downlink instructions include inquiry instructions, address encoding instructions, power detection instructions and distance measurement instructions;

[0025] The instruction protocol design module is further used to:

[0026] For the query instruction, the forward pulse of the first preset frequency is used as the pilot code, and multiple frequencies are used to form multiple frequency combinations by combining them in pairs as information codes. The multiple frequency combinations are combined with multiple time division strategies to obtain multiple different frequency and time division combinations;

[0027] For the address coding instruction, a binary frequency shift keying modulation method is adopted, each code element is assigned to one of two preset different frequencies according to its value, and the address coding instruction is set to include a pilot code, an information code and a check code;

[0028] For the power detection instruction, the forward pulse of the first preset frequency is used as the guide code, and the information code is set with different frequencies to make the power detection instruction different from the inquiry instruction;

[0029] For the ranging instruction, the forward pulse of the first preset frequency is used as the guide code, and multiple frequencies are combined in pairs to form multiple frequency combinations as information codes. The multiple frequency combinations are combined with multiple time division strategies to obtain multiple different frequency division and time division combinations, and signal processing and delay measurement are performed.

[0030] Furthermore, the uplink instruction includes a response instruction and a power detection uplink instruction; the response instruction includes a narrowband signal response instruction and a broadband signal response instruction; the broadband signal response instruction includes a broadband linear frequency modulation signal response instruction and a broadband spread spectrum signal response instruction;

[0031] The instruction protocol design module is further used to:

[0032] For the narrowband signal response instruction, the forward pulse is used as the reply signal, the signal of the second preset frequency is used as the pilot code, multiple frequencies are combined into multiple frequency combinations by two-by-two to form multiple reply channels, and the total length of the narrowband signal response instruction is set;

[0033] For broadband linear frequency modulation signal response instructions, multiple frequencies are used as center frequencies, and the bandwidth and duration of the signal of each frequency are set;

[0034] For the broadband spread spectrum signal response instruction, a pseudo-random sequence is used as the broadband spread spectrum signal response instruction of the transponder;

[0035] For the power detection uplink instruction, the forward pulse of the second preset frequency is used as the pilot code, and the information code with a preset number of bits is used to represent the transponder power. Each code element adopts binary frequency shift keying modulation and a check code is set.

[0036] Furthermore, the signal processing module is further configured to:

[0037] The frequency domain fast correlation method is used to solve the broadband signal, and the spread spectrum signal recognition method based on code division multiple access is used to detect the broadband signal.

[0038] According to the technical solution provided by the present invention, two transceiver devices, wireless coils and transducers, are designed respectively for different usage requirements of the transponder on deck and underwater. Through electromagnetic induction and hydroacoustic communication and corresponding hardware circuits, the shipborne transceiver can well meet the interaction requirements with the transponder in various usage scenarios; the shipborne transceiver adopts a frequency selection module to conveniently complete the detection of narrowband signals. The processor is connected to the output end of the frequency selection module and detects whether the narrowband signal has arrived through the level state of the GPIO interface. During the detection process, the processor only needs to use a timer to determine the arrival time of each forward pulse, without the need for complex software processing algorithms, thereby effectively reducing the power consumption of the entire machine; combining time division and frequency division technology, the command protocol design of the shipborne transceiver's downlink instructions to the transponder is conveniently completed. The query instruction selects a combination of multiple frequency signals combined with a variety of different time division strategies to define different query codes for multiple groups of transponders; the address coding instruction adopts binary frequency shift The keying modulation method effectively improves the reliability of the signal and reduces multipath interference through the combination of pilot code, information code and check code; in broadband signal detection, each transponder is assigned a unique address code using code division multiple access technology and spread spectrum technology, which not only enables them to work simultaneously in the same frequency band without interfering with each other, but also greatly improves the utilization of the frequency band; the fast sliding correlation signal processing method is used to perform frequency domain correlation on each subsequence separately, and finally the correlation results of each subsequence are synthesized into a complete correlation sequence in sequence, which not only significantly reduces the amount of calculation and memory usage, but also ensures that the system can meet the needs of real-time detection, greatly improving the efficiency of the real-time system in processing long sequence data; in order to overcome the problems of multipath effect and sound wave attenuation during the propagation of underwater acoustic signals, the shipborne transceiver can effectively improve the ranging accuracy of the shipborne transceiver and the anti-interference ability of communication through the hardware circuits of the transmitting unit and the receiving unit and the detection algorithm of the broadband signal and the narrowband signal.

[0039] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0041] Figure 1 A structural block diagram of a shipborne transceiver used in an underwater acoustic positioning system according to an embodiment of the present application is shown;

[0042] Figure 2 shows a schematic diagram of a knob matrix circuit;

[0043] Figure 3 shows a schematic diagram of a debounce reset switch circuit;

[0044] Figure 4 shows a schematic diagram of a display screen control circuit;

[0045] Figure 5 shows a schematic diagram of a buzzer driving circuit;

[0046] Figure 6 The figure shows the power supply architecture of the shipborne transceiver.

[0047] Figure 7 shows a schematic diagram of a power supply circuit;

[0048] Figure 8 shows a schematic diagram of a battery charge detection circuit;

[0049] Figure 9 shows a schematic diagram of a battery charging protection circuit;

[0050] Figure 10 shows a structural block diagram of a receiving unit;

[0051] Figure 11 shows a schematic diagram of a fourth-order Butterworth filter;

[0052] Figure 12 shows a schematic diagram of a signal shaping circuit;

[0053] Figure 13 shows a schematic diagram of a frequency selection module;

[0054] Figure 14 shows a structural diagram of a wireless coil;

[0055] Figure 15 shows a structural block diagram of a transmitting unit;

[0056] Figure 16shows a schematic diagram of the LM386 minimum gain circuit;

[0057] Figure 17 shows a schematic diagram of a transmit drive circuit;

[0058] Figure 18 shows the anti-dead zone waveform timing diagram;

[0059] Figure 19 Shows the software design framework diagram of the underwater acoustic positioning system;

[0060] Figure 20 A schematic diagram of an inquiry instruction is shown;

[0061] Figure 21 A schematic diagram of an address encoding instruction is shown;

[0062] Figure 22 A schematic diagram of a power detection instruction is shown;

[0063] Figure 23 A schematic diagram showing a narrowband signal response instruction;

[0064] Figure 24 A schematic diagram of a narrowband signal detection process is shown;

[0065] Figure 25 Shows a schematic diagram of frequency domain fast correlation Figure 1 ;

[0066] Figure 26 Shows a schematic diagram of frequency domain fast correlation Figure 2 ;

[0067] Figure 27 A schematic diagram of a mathematical model of a spread spectrum communication transmitter system is shown;

[0068] Figure 28 shows a flow chart of the ranging function;

[0069] Figure 29 A schematic diagram of the address encoding function is shown;

[0070] Figure 30 Shows a flow chart of the power detection function;

[0071] Figure 31 The flowchart of the shipborne transceiver's electrical quantity self-test function is shown. DETAILED DESCRIPTION

[0072] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0073] Figure 1 FIG. 1 shows a structural block diagram of a shipborne transceiver used in an underwater acoustic positioning system according to an embodiment of the present application. Figure 1 As shown, the shipborne transceiver includes: a processing unit 110 , a receiving unit 120 , a transmitting unit 130 and a transceiver device 140 .

[0074] The processing unit 110 includes a processor 1101 and its peripheral circuits. Processor 1101 is used for analog-to-digital signal conversion. In practical applications, processor 1101 can utilize the NUCLEO-U575ZI development board based on the STM32U575 microcontroller. The STM32U575 microcontroller has built-in 14-bit ADC and DAC modules for analog-to-digital signal conversion. The peripheral circuits include an operation panel circuit (not shown), a power supply circuit 1102, a battery charge detection circuit 1103, and a battery charging protection circuit 1104.

[0075] Regarding the button configuration of the operation panel, multiple multi-channel knobs and multiple self-resetting switch buttons can be selected as control buttons 1105, such as four 10-channel knobs and three self-resetting switch buttons. Regarding the display 1106, a DDM4 liquid crystal display can be selected. The operation panel is also equipped with an active buzzer as a feedback device for providing audio feedback. The operation panel circuit includes a button control circuit, a display screen control circuit, and a buzzer drive circuit. Among them, the button control circuit includes a knob matrix circuit and a debounce reset switch circuit. The schematic diagram of the knob matrix circuit is shown in FIG. Figure 2 The shipborne transceiver is also controlled by three reset switch buttons. The hardware debounce chip MAX6816 can be used to process the button signals. The schematic diagram of the debounce reset switch circuit is shown in the figure below. Figure 3 The display screen control circuit is used to drive the display so that the display can display the real-time status information of the shipborne transceiver, such as key parameters such as signal strength and operating frequency. The schematic diagram of the display screen control circuit is shown in Figure 4 The buzzer drive circuit is used to drive the buzzer to sound when the shipboard transceiver successfully receives the transponder feedback after sending a command. When the shipboard transceiver successfully receives the transponder feedback after sending a command, the buzzer drive circuit drives the buzzer to emit a clear sound, providing an intuitive auditory confirmation of the operation result. The schematic diagram of the buzzer drive circuit is shown as follows Figure 5shown.

[0076] To meet diverse functional requirements, the shipboard transceiver features a convenient operation panel that provides intuitive operation instructions and clear information display, reducing the number of steps required. This panel displays input and output results, and allows for input using buttons or a rotary knob, effectively ensuring that operators can easily configure the device, monitor status, and query data. Operators use the rotary knob and buttons to select the transceiver's operating mode and then view the results on the display.

[0077] Considering that the overall power consumption of the underwater acoustic positioning system does not exceed 50 mA, and that all circuits of the underwater acoustic positioning system except the processor 1101 require a 5V power supply, the power supply circuit 1102 can use the TPS54331 DC-DC (direct current-direct current) conversion chip. Figure 6 The figure shows a schematic diagram of the power supply architecture of the shipborne transceiver, which clearly shows the various links and components of power management. Among them, the battery voltage VBAT is 12.6V, the power supply of the power circuit is 5V, and the power supply of the processor includes 3.3V and 1.8V. Figure 7 shows a schematic diagram of the power supply circuit, as Figure 7 As shown, the output voltage of the power supply circuit can be adjusted externally. The voltage divider network consists of R O1 and R O2 Formula (1) and formula (2) are the output voltage relationship. Set the output voltage to 5V and use R O1 =10.2kΩ,R O2 =1.91kΩ.

[0078] Formula (1)

[0079] Formula (2)

[0080] Among them, R O1 and R O2 are the two resistors in the voltage divider network, V ref is the reference voltage, V OUT is the output voltage.

[0081] In the power supply circuit, the minimum value of the output inductance is calculated by formula (3). Select the current ripple rate K IND =0.3, the minimum inductance value obtained by calculation is 5.7μH, and the inductor of 6.8μH is finally selected.

[0082] Formula (3)

[0083] Among them, L MIN is the minimum inductance value, V OUT(MAX) is the maximum output voltage, VIN(MAX) is the maximum input voltage, V OUT is the output voltage, K IND is the current ripple rate, I OUT is the output current, f SW is the switching frequency of the power chip.

[0084] The minimum capacitance value can be calculated from formula (4).

[0085] Formula (4)

[0086] Among them, C O(MIN) is the minimum capacitance value, R O is the output load impedance (V O / I O ), F CO(MAX) is the desired crossover frequency. So C O You can choose a ceramic capacitor with a capacitance value of 33μF and use two of them to form a 66μF capacitor.

[0087] The battery power detection circuit 1103 is used to detect the power of the battery 1107. The battery power detection circuit 1103 can use the LTC4151 chip. 2 The C bus interface communicates with the processor 1101. The schematic diagram of the battery power detection circuit 1103 is shown in FIG. Figure 8 shown.

[0088] For battery 1107, 3 series and 8 parallel 18650 lithium batteries can be used as the power source. The series connection of the batteries increases the total voltage of the battery to 12.6V, while the parallel connection increases the total capacity to 35200mAh. The battery charging protection circuit 1104 can use the DW01B chip to protect the charging and discharging of battery 1107. It is used to protect a single battery from overcharge and overdischarge. The schematic diagram of the battery charging protection circuit 1104 is shown below. Figure 9 As shown, three DW01B chips can be used to provide protection for three 18650 lithium batteries connected in series.

[0089] The receiving unit 120 of the shipborne transceiver is used to perform pre-processing such as amplification and filtering on the received signal (such as an analog signal). Figure 10 The structural block diagram of the receiving unit is shown in FIG. Figure 10As shown, the receiving unit 120 includes a function selection module 1201, a receiver 1202, a frequency selection module 1203, and an analog-to-digital conversion circuit 1204 (i.e., an A / D circuit). The transceiver 140 includes a wireless coil 1401 for use above water and a transducer 1402 for use underwater. The function selection module 1201 is used to change the operating environment of the shipboard transceiver and receive transponder signals through the transceiver 140. The receiver 1202 is used to pre-process the received signal and then, based on the signal type, select whether to send the received signal to the frequency selection module 1203 or the analog-to-digital conversion circuit 1204. If the received signal is a narrowband signal, it is sent to the frequency selection module 1203 for processing; if the received signal is a broadband signal, it is sent to the analog-to-digital conversion circuit 1204 for processing. The frequency selection module 1203 is used to perform frequency selection processing on the received signal if it is a narrowband signal.

[0090] Receiver 1202 includes a signal filtering and amplifying circuit and a signal shaping circuit. The signal filtering and amplifying circuit includes a differential amplifier circuit and a fourth-order Butterworth filter. The differential amplifier circuit can use the SSM2212 chip. The filtering uses a fourth-order Butterworth filter consisting of a second-order low-pass filter and a second-order high-pass filter. The schematic diagram of the fourth-order Butterworth filter is shown in the figure. Figure 11 As shown. The signal shaping circuit uses a voltage comparator to convert the sine wave into a corresponding square wave. In the specific design, the amplitude of all signals can be limited to 2.5V. The voltage comparator can be TLC3702. The schematic diagram of the signal shaping circuit is shown as follows Figure 12 shown.

[0091] After the shaped signal passes through the receiver 1202 and enters the frequency selection module 1203, it will determine whether the input signal is a narrowband signal. If it is a narrowband signal, the signal will be further processed. The frequency selection module 1203 includes a narrowband bandpass filter constructed by multiple groups of capacitors and inductors. The schematic diagram of the frequency selection module 1203 is shown in FIG. Figure 13 As shown in Figure 5, the inductor parameters determine its specific frequency selection characteristics. According to the specified frequency requirements, the values ​​of L and C are obtained from the cutoff frequency calculation formula (5) of the capacitor-inductor filter.

[0092] Formula (5)

[0093] Among them, f0 is the cutoff frequency of the capacitor-inductor filter, L is the inductor, and C is the capacitor.

[0094] From the calculation, we can conclude that: for signal 1 with a pass frequency of 13kHz: L1=32mH, C1=4700pF; for signal 2 with a pass frequency of 15kHz: L2=31mH, C2=3600pF; for signal 3 with a pass frequency of 17kHz: L3=29mH, C3=3000pF.

[0095] Transceiver 140 includes a wireless coil 1401 and a transducer 1402. Wireless coil 1401 is used above water, while transducer 1402 is used underwater, adapting to both above-water and underwater operating environments. On the surface, the shipboard transceiver exchanges information with the transponder via electromagnetic induction via wireless coil 1401. Underwater, the shipboard transceiver communicates with the transponder via acoustic signals via transducer 1402.

[0096] Considering the relatively open and less interfering characteristics of the aquatic environment, the structure and material selection of the wireless coil 1401 are optimized in this application. In practical applications, the wireless coil 1401 can use 10 turns of copper wire to increase the magnetic flux of the electromagnetic field, and use silicone rubber for vulcanization reaction to fully ensure its sealing. The structure diagram of the wireless coil is shown in the figure below. Figure 14 shown.

[0097] like Figure 1 As shown, the transmitting unit 130 is mainly responsible for generating and sending signals, specifically for driving the transceiver device 140 to transmit signals to communicate with the transponder, wherein different communication circuits are set for different transceiver devices. Specifically, the transmitting unit 130 includes a wireless coil communication circuit used on the deck, a transducer communication circuit used underwater, and a digital-to-analog conversion circuit (i.e., a D / A circuit). Figure 15 The structural block diagram of the transmitting unit is shown in FIG. Figure 15 As shown, two different sets of drive circuits and power amplifiers are used for different transceiver devices. The transmitting unit includes a wireless coil communication circuit, a transducer communication circuit, and a digital-to-analog conversion circuit 1301. The wireless coil communication circuit includes a linear power amplifier circuit 1302 and a filter 1303. Linear power amplifier circuit 1302 drives wireless coil 1401 to transmit signals. The transducer communication circuit includes a Class D power amplifier circuit 1304 and a transmit driver circuit 1305. Class D power amplifier circuit 1304 drives transducer 1402 to transmit signals. Class D power amplifier circuit 1304 is a Class D audio power amplifier, sometimes also called a digital power amplifier circuit. Transmitter driver circuit 1305 is used to boost current and perform dead-zone processing on the transmitted signal.

[0098] In order to drive the wireless coil 1401 to work, the linear power amplifier circuit 1302 can use a linear power amplifier LM386. When using the LM386, it is configured to the minimum gain mode by not adding any gain setting resistors and capacitors between pins 1 and 8. The schematic diagram of the LM386 minimum gain circuit is shown as follows: Figure 16 shown.

[0099] The transmit driver circuit 1305 takes over from the processor 1101, followed by the Class D power amplifier circuit 1304, which performs current boost and dead-zone processing on the transmit signal. The transmit signal passes through the CD4013B chip, is divided into two directions, and then sent to the MOS transistor driver chip CD54HC40103. The chip guides the signal to the Class D power amplifier circuit, and finally the power amplifier outputs it. The schematic diagram of the transmit driver circuit 1305 is shown in Figure 1. Figure 17 shown.

[0100] To ensure circuit safety, a slight delay adjustment is made to the positive and negative waveforms of the Class D power amplifier circuit 1304. The waveform timing diagram is shown in FIG. Figure 18 As shown in the figure, U5-Q2 represents the waveform of the Q2 pin of the U5 component, U5-Q1 represents the waveform of the Q1 pin of the U5 component, U5-Q1' represents the waveform of the Q1' (i.e., Q1-) pin of the U5 component, U8-1Y represents the waveform of the 1Y pin of the U8 component, and U8-4Y represents the waveform of the 4Y pin of the U8 component. By introducing a time difference, the simultaneous start-up of the MOS power transistors is effectively avoided, reducing the risk of circuit conflicts.

[0101] The Class D amplifier circuit 1304 can use the IRL8113S as a power tube and use a 12.6V power supply. Based on the parameters of the transducer 1402, the required 180dB sound source level requires a 400V drive voltage, while the drain-source voltage is 25V. Therefore, the transformer ratio is:

[0102] Formula (6)

[0103] Where n is the transformer ratio, U L is the required voltage, U i is the drain-source voltage.

[0104] In this application, the processor is always powered on, and the transmitter and transceiver are in a low-power standby state. The power consumption of the shipboard transceiver is no more than 50mA when the Class D amplifier is not transmitting, effectively reducing the power consumption of the shipboard transceiver and extending its standby time. To overcome the multipath effect and sound wave attenuation problems of underwater acoustic signal propagation, the shipboard transceiver effectively improves the ranging accuracy and anti-interference ability of the shipboard transceiver through the hardware circuits of the transmitter and receiver units and the detection algorithm for broadband and narrowband signals.

[0105] The present invention also provides an underwater acoustic positioning system, comprising a command protocol design module, a signal processing module, and a shipboard transceiver as described above for use in the underwater acoustic positioning system. The command protocol design module is configured to design protocols for downlink commands from the shipboard transceiver to the transponder, and for uplink commands from the transponder to the shipboard transceiver. The transponders are divided into multiple groups, and each group is assigned multiple channels to form multiple transponder combinations. The signal processing module is configured to process received signals using a preset algorithm.

[0106] According to the working function of the shipborne transceiver, the software structure of the underwater acoustic positioning system can be divided into four main parts: ranging, address encoding, power detection and transceiver power detection. The overall software structure is organized into a framework diagram, as shown in the following figure: Figure 19 As shown in the figure, the system is ready and receives button commands. The transceiver determines if the operating environment is underwater, then transmits an interrogation signal via a transducer; if the operating environment is above water, then transmits an interrogation signal via a wireless coil. The ADC polls and receives signals to determine if the received signal is correct. If correct, the command type is determined. If not, the display indicates a failure. If the command type determines that it is a response function, a response check is performed, a success message is displayed on the display, and a buzzer sounds. If the command type determines that it is a ranging function, the distance is calculated and displayed on the display. If the command type determines that it is an identity code encoding (i.e., address encoding) function, a response check is performed, a success message is displayed on the display, and a buzzer sounds. If the command type determines that it is a power detection function, the power is calculated and the voltage is displayed on the display. If the transceiver determines that the operating environment is internal to the system, the shipboard transceiver performs a power check, measures the voltage, and displays the voltage on the display. To implement these functions, the overall software design is divided into several parts: command protocol design, signal processing algorithm, and system software implementation.

[0107] For example, in the protocol designed for the underwater acoustic positioning system, transponders are divided into 128 different groups, each of which is further divided into 8 different channels, totaling 1024 transponder combinations, which can realize the coordinated target positioning function of 1024 transponders.

[0108] Downlink instructions include instruction protocols for implementing various functions, which may specifically include inquiry instructions, address encoding instructions, power detection instructions, and distance measurement instructions.

[0109] The instruction protocol design module is further used to: for the inquiry instruction, use the forward pulse of the first preset frequency as the guide code, use multiple frequencies to form multiple frequency combinations as information codes by combining them in pairs, combine the multiple frequency combinations with multiple time division strategies to obtain multiple different frequency division and time division combinations; for the address coding instruction, use the binary frequency shift keying modulation method, each code element is assigned to one of two preset different frequencies according to its value, and set the address coding instruction to include a guide code, an information code and a check code; for the power detection instruction, use the forward pulse of the first preset frequency as the guide code, use different frequencies to set the information code, so that the power detection instruction is different from the inquiry instruction; for the ranging instruction, use the forward pulse of the first preset frequency as the guide code, use multiple frequencies to form multiple frequency combinations as information codes by combining them in pairs, combine the multiple frequency combinations with multiple time division strategies to obtain multiple different frequency division and time division combinations, and perform signal processing and delay measurement.

[0110] Specifically, the inquiry command uses four frequencies f1, f2, f3, and f4, where frequency f1 is the first preset frequency. The forward pulse of f1 (i.e., CW pulse) is used as a pilot code to notify the transponder of the arrival of the inquiry signal. Subsequently, the remaining three frequencies are combined in pairs to form three different frequency combinations as information codes (or information code chips). By combining these frequency combinations with 43 different time division strategies, a total of 128 different frequency and time division combinations can be obtained. The schematic diagram of the inquiry command is shown below. Figure 20 As shown in Figure 1, the total length of the interrogation command can be τ. The intersymbol interval a starts at τ1 and increases by 5ms; the intersymbol interval b starts at τ2 and decreases by 5ms. There are 43 variations of the time division protocol. The ranging command is the same as the interrogation command, except that further signal processing is performed to measure the delay.

[0111] The address coding instruction adopts binary frequency shift keying (BFSK) modulation, and each code element is assigned to one of two preset different frequencies according to its value (0 or 1). In order to improve the reliability of the signal and reduce the influence of multipath interference, each set of address coding instructions can contain three parts: pilot code, information code and check code. The schematic diagram of the address coding instruction is shown below. Figure 21 The last check bit in the address encoding instruction determines the accuracy of the signal through parity check. If the sum is an odd number, the check bit is set to 1; if the sum is an even number, the check bit is set to 0.

[0112] The power detection instruction uses the CW pulse of f1 as the guide code, and the first information code is set to f5 and the last information code is set to f0 to ensure that it will not be repeated with the query instruction. The schematic diagram of the power detection instruction is as follows Figure 22 shown.

[0113] The uplink instruction is mainly used to implement the response instruction and the power detection uplink instruction, while the ranging uplink instruction and the address coding uplink instruction are consistent with the response instruction. Among them, the uplink instruction includes the response instruction and the power detection uplink instruction; the response instruction includes the narrowband signal response instruction and the broadband signal response instruction. The instruction protocol design module is further used to: for the narrowband signal response instruction, use the forward pulse as the reply signal, use the signal of the second preset frequency as the pilot code, use multiple frequencies to form multiple frequency combinations by combining them in pairs, form multiple reply channels, and set the total length of the narrowband signal response instruction. For example, the narrowband signal response instruction uses a CW pulse as the reply signal, the frequency f11 is the second preset frequency, and the signal of the frequency f11 is used as the pilot code. Then, the five frequencies of f12, f13, f14, f15 and f16 are used in pairs to form 8 groups to form 8 different reply channels. Figure 23 A schematic diagram of a narrowband signal response instruction is shown, such as Figure 23 As shown, the total length of the narrowband signal response instruction is fixed to τ, the inter-code interval a is τ1, and the inter-code interval b is τ2.

[0114] The broadband signal response instructions include broadband linear frequency modulation signal response instructions and broadband spread spectrum signal response instructions. The command protocol design module is further configured to: for broadband linear frequency modulation signal response instructions, use multiple frequencies as the center frequency and set the bandwidth and duration of the signal for each frequency; for broadband spread spectrum signal response instructions, use a pseudo-random sequence as the broadband spread spectrum signal response instruction of the transponder.

[0115] For example, for a broadband linear frequency modulation signal response command, the center frequency can be eight different frequencies, each with a 2kHz bandwidth and a duration of τ0. For a broadband spread spectrum signal response command, a 127-bit Gold sequence generated by a 7th-order m-sequence can be selected as the broadband spread spectrum signal response command of the transponder, and eight balanced Gold sequences are selected.

[0116] The command protocol design module is further used to: for the power detection uplink command, the forward pulse of the second preset frequency is used as the pilot code, and the information code with a preset number of bits is used to represent the transponder power, wherein each code element adopts binary frequency shift keying modulation and a check code is set. The power detection uplink command also adopts binary frequency shift keying modulation. The CW pulse of frequency f11 is used as the pilot code, and then a 10-bit information code is used to represent the transponder power, wherein each code element adopts BFSK modulation, 0 code element corresponds to f12, and 1 code element corresponds to f13; the last check code is used to determine the accuracy of the signal through parity check.

[0117] In the shipborne transceiver, the detection of narrowband signals is implemented through hardware circuits. The arrival of the signal is detected by the level status of the GPIO interface. Specifically, the processor in the processing unit of the shipborne transceiver is connected to the output end of the frequency selection module and detects the arrival of the narrowband signal through the level status of the GPIO interface. Figure 24 FIG. 1 shows a flow chart of narrowband signal detection. Figure 24 As shown, the transceiver receives a signal; the receiver receives a signal; it determines whether the frequency selection network recognizes the 33kHz pilot code; if the 33kHz pilot code is recognized, it is sent to the processor GPIO, the processor determines it to be a single-frequency signal, and prepares to judge other frequency selection network GPIOs, and then determines whether the first information code is received; if the first information code is received, it continues to determine whether the second information code is received; if the second information code is received, it determines whether the delay is accurate. If the delay is accurate, it determines that the transponder responds successfully; if the first information code is not received, or the second information code is not received, or the delay is inaccurate, it determines that the transponder responds failed; if the 33kHz pilot code is not recognized, the access processor AD starts to collect data and performs other forms of signal detection.

[0118] When the frequency selection network recognizes the pilot code, it turns on the GPIO interfaces for all frequencies and sets them to input status. A timer is then used for precise timing control. When the interval with the leading edge of the pilot code is 100ms, the onboard transceiver begins window detection. When the interval with the leading edge of the pilot code is τ, the onboard transceiver performs window detection again. This allows the frequency and arrival time of the pilot code and the two-bit information code to be determined. This recognition method not only improves signal reception accuracy but also helps mitigate the impact of environmental multipath on signal reception.

[0119] Due to the time-bandwidth product characteristic of broadband linear frequency modulation signals, pulse compression techniques can improve temporal resolution. To enhance the ability to accurately identify the arrival time of interrogation signals, this application employs a correlation method to resolve broadband signals. The signal processing module further utilizes frequency-domain fast correlation methods to resolve broadband signals and a spread spectrum signal recognition method based on code division multiple access for broadband signal detection.

[0120] In broadband signal detection, the copy correlator is processed in a discrete form. Assuming two causal signals x(n) and y(n), to calculate the correlation between the two signals x(n) and y(n), a convolution calculation strategy can be adopted. In this application, the signal processing module can use frequency domain multiplication to perform convolution operations, which converts the signal to the frequency domain through FFT and then returns to the time domain through IFFT. The linear convolution expression of the sequence x(n) of length L and the length y(n) of length M is:

[0121] Formula (7)

[0122] Where z(n) is the output sequence, y(l) is the reference signal 1, x(nl) is the reference signal 2, and M is the length of the y(n) sequence.

[0123] Then the length of z(n) is L+M-1. When the circular convolution is equal to the linear convolution, it can avoid aliasing in the frequency domain. Taking N≥L+M-1, we get:

[0124] Formula (8)

[0125] Formula (9)

[0126] The specific expression is as follows:

[0127] Formula (10)

[0128] Formula (11)

[0129] Formula (12)

[0130] Formula (13)

[0131] Figure 25 Shows a schematic diagram of frequency domain fast correlation Figure 1 ,like Figure 25 As shown, first flip the y(n) sequence and perform an N-point FFT on it to obtain Y(k). Next, perform an N-point FFT on the x(n) sequence to obtain X(k). Multiplying the sequence yields Z(k), and performing an N-point IFFT on Z(k) yields z(n).

[0132] In real-time signal processing, when faced with the need to perform fast frequency-domain correlation calculations on a long input sequence x(n) and a short reference signal y(n), direct processing will lead to a surge in computing resource requirements due to the need for a large amount of zero padding in y(n). Figure 26 Shows a schematic diagram of frequency domain fast correlation Figure 2 In this application, we propose to use the overlap retention method for fast sliding correlation. The steps are as follows: the length of the sequence y(n) is M, the input sequence x(n) is divided into several parts of equal length L, and L is approximately equal to M. Then, MN zeros are added after y(n) to obtain y N (n), the expression of N is N=2 k ≥L+M-1, then add NL zeros to the front of the first sequence after dividing it into L lengths, and then add it to y N(n) Perform frequency domain fast correlation to obtain N-point correlation outputs, discard the first M-1 points, retain the remaining points, and then combine the retained points each time to obtain the output sequence z(n).

[0133] The processor in the underwater acoustic positioning system collects data in real time through an ADC and designs a program to implement a multi-level buffer. An algorithm adapted to the signal processing module is used to meet the requirements of real-time signal processing. Assuming the reference signal length is N, it is expanded to 2N points by adding zeros. Two buffers are set, each with N points. Using the overlapping retention method, the first N points of the two buffers are linked to the last N points of the previous buffer. The next N points represent new data collected in the current buffer. The data in each buffer is then correlated with the local signal, and the last N points of the correlation result are retained as the correlation output sequence. The system's fast sliding correlation scheme effectively increases the speed of data processing, ensuring that the underwater acoustic positioning system can achieve efficient real-time signal detection and processing.

[0134] When the processor performs copy correlation calculations on the received signal, a large number of zero-padding operations need to be performed on the reference signal, which consumes a large amount of memory and computing power. In order to reduce the consumption of memory and computing power, this application adopts a fast sliding correlation algorithm in real-time signal processing, which can greatly improve the efficiency of processing long sequence data.

[0135] This application introduces wideband signal detection using spread spectrum signal identification based on code division multiple access (CDMA) technology. This technology allows multiple users to communicate simultaneously within the same frequency band using a unique pseudorandom sequence assigned to each user. Pseudorandom sequences can be used in spectrum expansion and are referred to as spreading code sequences. Figure 27 A schematic diagram of the mathematical model of a spread spectrum communication transmitter system is shown in FIG. Figure 27 As shown, the expression of its output signal is:

[0136] Formula (14)

[0137] Where f0 is the center frequency of the carrier, A is the amplitude of the signal, is the initial phase of the carrier, is the carrier phase controlled by the binary sequence, Figure 27 Where d(t) and c(t) are spread spectrum code waveforms.

[0138] Satisfying formula (14), d(t) is used to represent the encoded data stream {a n}, the transmitted signal s(t) is:

[0139] Formula (15)

[0140] In this application, the Gold sequence is used as a pseudo-random sequence. The protocol uses eight 127-bit balanced Gold sequences generated from a 7th-order m-sequence as the transponder's wideband spread-spectrum signal response instructions. The modulated carrier frequency is 24 kHz, and the Gold sequence exhibits excellent autocorrelation and low cross-correlation. Balanced Gold sequences have excellent autocorrelation and zero cross-correlation, making them suitable for use as transponder wideband spread-spectrum signal response instructions.

[0141] Combined with the above-mentioned introduction to the hardware and software, the various functional implementation processes of the underwater acoustic positioning system of this application are introduced as follows.

[0142] The ranging function is a process in which the ship's transceiver sends a query command to the transponder and then polls the ADC to wait for the transponder's response signal. The time difference between sending the query command and receiving the response signal is then measured, allowing the underwater acoustic positioning system to calculate the distance the signal has traveled. Figure 28 The flow chart of the ranging function is shown in FIG. Figure 28 As shown, after receiving the ranging command, the transmitter (i.e., the transceiver) sends an inquiry command, and the signal processing receives the response signal. If the response is successful, the distance is calculated and the display shows the distance; if the response fails, the display shows failure.

[0143] In underwater acoustic positioning systems, the address encoding function is primarily used for transponder deployment. It utilizes not only the interrogation and response functions but also knob input and on-screen controls to enhance user interactivity and intuitive operation. The knob matrix allows operators to easily set or adjust the transponder's address, while the on-screen controls provide real-time operational feedback and address configuration status. The address encoding function simplifies the transponder deployment process and improves the user experience of the communication system. Figure 29 The flowchart of the address encoding function is shown in FIG. Figure 29 As shown, the address coding instruction is received, the knob identity code number is read, and a 10-bit information code is generated based on the number; the coding instruction is transmitted for the first time, and the coding instruction is transmitted for the second time; the transmitter transmits an inquiry instruction, and the signal processing receives the response signal. If the response is successful, the display shows success; if the response fails, the display shows failure.

[0144] The battery level detection function decodes narrowband signals to obtain transponder battery level information. It uses a frequency-selective network to detect and analyze the signal, extracting the 10-bit information code and 1-bit check code sent by the transponder. The 10-bit information code contains the transponder battery level, while the check code ensures the integrity and accuracy of the received data. Figure 30 The flow chart of the power detection function is shown in FIG. Figure 30As shown, a power detection instruction is received and a power detection instruction is transmitted; a frequency selection network is used to detect and analyze the signal to extract each information code and check code; each information code is detected in turn to see if it is correct, whether the time delay is correct, and whether the check code is correct; if any information code is incorrect, the time delay is incorrect, or the check code is incorrect, the display shows that the power detection has failed; if each information code, time delay, and check code are correct, the power is calculated and the display shows the power.

[0145] The shipborne transceiver power self-test function is realized by real-time monitoring of the power status of the device. This function first performs button polling to confirm the start of power self-test. After receiving the shipborne transceiver power self-test command, the power is automatically checked by I 2 C bus, connect the battery power detection circuit and the processor, start the shipborne transceiver power self-test, the battery detection IC then starts the voltage acquisition program, calculates the voltage value, and the display shows the voltage value. The flow chart of the shipborne transceiver power self-test function is as follows Figure 31 shown.

[0146] According to the technical solution provided in the embodiment of the present application, two transceiver devices, wireless coils and transducers, are designed respectively for different usage requirements of the transponder on deck and underwater. Through electromagnetic induction and hydroacoustic communication and corresponding hardware circuits, the shipborne transceiver can well meet the interaction requirements with the transponder in various usage scenarios; the shipborne transceiver adopts a frequency selection module to conveniently complete the detection of narrowband signals. The processor is connected to the output end of the frequency selection module and detects whether the narrowband signal has arrived through the level state of the GPIO interface. During the detection process, the processor only needs to use a timer to determine the arrival time of each forward pulse, without the need for complex software processing algorithms, thereby effectively reducing the power consumption of the entire machine; combining time division and frequency division technology, the command protocol design of the shipborne transceiver's downlink instructions to the transponder is conveniently completed. The query instruction selects a combination of multiple frequency signals combined with a variety of different time division strategies to define different query codes for multiple groups of transponders; the address coding instruction adopts binary The frequency shift keying modulation method effectively improves the reliability of the signal and reduces multipath interference through the combination of pilot code, information code and check code; in broadband signal detection, each transponder is assigned a unique address code using code division multiple access technology and spread spectrum technology, which not only enables them to work simultaneously in the same frequency band without interfering with each other, but also greatly improves the utilization of the frequency band; the fast sliding correlation signal processing method is used to perform frequency domain correlation on each subsequence separately, and finally the correlation results of each subsequence are synthesized into a complete correlation sequence in sequence, which not only significantly reduces the amount of calculation and memory usage, but also ensures that the system can meet the needs of real-time detection, greatly improving the efficiency of the real-time system in processing long sequence data; in order to overcome the problems of multipath effect and sound wave attenuation during the propagation of underwater acoustic signals, the shipborne transceiver can effectively improve the ranging accuracy and communication anti-interference ability of the shipborne transceiver through the hardware circuits of the transmitting unit and the receiving unit and the detection algorithm of the broadband signal and the narrowband signal.

[0147] The algorithm and display provided herein are not inherently related to any particular computer, virtual system or other device. Various general-purpose systems can also be used together with the teachings based on this. According to the above description, it is obvious that the structure required for constructing this type of system. In addition, the present invention is not directed to any specific programming language. It should be understood that various programming languages ​​can be utilized to realize the content of the present invention described herein, and the above description of specific languages ​​is for the purpose of disclosing the best mode of the present invention.

[0148] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0149] Similarly, it should be understood that in order to streamline the present disclosure and aid understanding of one or more of the various inventive aspects, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the claims, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Accordingly, the claims that follow the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the invention.

[0150] Those skilled in the art will appreciate that the modules in the devices of the embodiments can be adaptively modified and installed in one or more devices different from the embodiments. The modules, units, or components in the embodiments can be combined into a single module, unit, or component, and furthermore, they can be divided into multiple sub-modules, sub-units, or sub-components. All features disclosed in this specification (including the accompanying claims, abstract, and drawings), and all processes or units of any method or device disclosed therein, can be combined in any combination, unless at least some of such features and / or processes or units are mutually exclusive. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0151] Furthermore, those skilled in the art will appreciate that although some embodiments described herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are intended to be within the scope of the present invention and to form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

[0152] The various component embodiments of the present invention may be implemented in hardware, as software modules running on one or more processors, or as a combination thereof. Those skilled in the art will appreciate that, in practice, a microprocessor or digital signal processor (DSP) may be used to implement some or all of the functionality of some or all of the components according to the embodiments of the present invention. The present invention may also be implemented as an apparatus or device program (e.g., a computer program or computer program product) for performing part or all of the methods described herein. Such a program implementing the present invention may be stored on a computer-readable medium or in the form of one or more signals. Such signals may be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0153] It should be noted that the above embodiments illustrate rather than limit the invention, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between brackets should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising several different elements and by means of appropriately programmed computers. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

Claims

1. A shipborne transceiver used in an underwater acoustic positioning system, characterized in that: The shipborne transceiver includes: a processing unit, a receiving unit, a transmitting unit and a transceiver device; The processing unit includes a processor and a peripheral circuit of the processor; the processor is used for converting analog signals and digital signals; the peripheral circuit includes an operation panel circuit, a power supply circuit, a battery power detection circuit and a battery charging protection circuit; The receiving unit includes a function selection module, a receiver, a frequency selection module, and an analog-to-digital conversion circuit; the function selection module is used to change the working environment of the shipborne transceiver and receive the transponder signal through the transceiver; the receiver is used to pre-process the received signal and select the received signal to be sent to the frequency selection module or the analog-to-digital conversion circuit according to the signal form; the frequency selection module is used to perform frequency selection processing on the received signal when the received signal is a narrowband signal; The transmitting unit is used to drive the transceiver device to transmit a signal to communicate with the transponder; The transceiver device includes a wireless coil for use in an above-water environment and a transducer for use in an underwater environment.

2. The shipborne transceiver for use in an underwater acoustic positioning system according to claim 1, characterized in that: The operation panel circuit includes a button control circuit, a display screen control circuit and a buzzer drive circuit; The button control circuit includes a knob matrix circuit and a de-jitter reset switch circuit; The display screen control circuit is used to drive the display so that the display displays the real-time status information of the shipborne transceiver; The buzzer driving circuit is used to drive the buzzer to sound when the shipborne transceiver successfully receives feedback from the transponder after sending a command.

3. The shipborne transceiver for use in an underwater acoustic positioning system according to claim 1, characterized in that: The receiver includes a signal filtering and amplifying circuit and a signal shaping circuit; The signal filtering and amplifying circuit includes a differential amplifier circuit and a fourth-order Butterworth filter; The signal shaping circuit converts a sine wave into a corresponding square wave using a voltage comparator.

4. The shipborne transceiver for use in an underwater acoustic positioning system according to claim 1, characterized in that: The frequency selection module includes a narrowband bandpass filter constructed by multiple groups of capacitors and inductors.

5. The shipborne transceiver for use in an underwater acoustic positioning system according to claim 1, characterized in that: The transmitting unit includes a wireless coil communication circuit, a transducer communication circuit and a digital-to-analog conversion circuit; The wireless coil communication circuit includes a linear power amplifier circuit and a filter; the linear power amplifier circuit is used to drive the wireless coil to transmit a signal; The transducer communication circuit includes a class D power amplifier circuit and a transmitting drive circuit; the class D power amplifier circuit is used to drive the transducer to transmit a signal; the transmitting drive circuit is used to perform current enhancement and dead zone processing on the transmitting signal.

6. The shipborne transceiver for use in an underwater acoustic positioning system according to any one of claims 1 to 5, characterized in that: The processor is connected to the output end of the frequency selection module and detects whether a narrowband signal arrives through the level state of the GPIO interface.

7. An underwater acoustic positioning system, characterized in that: It comprises a command protocol design module, a signal processing module and a shipborne transceiver for use in an underwater acoustic positioning system according to any one of claims 1 to 6; The command protocol design module is used to design protocols for downlink commands from the shipborne transceiver to the transponder and uplink commands from the transponder to the shipborne transceiver; wherein the transponders are divided into multiple groups and each group is divided into multiple channels to form multiple transponder combinations; The signal processing module is used to: use a preset algorithm to perform signal processing on the received signal.

8. The underwater acoustic positioning system according to claim 7, characterized in that: The downlink instructions include inquiry instructions, address encoding instructions, power detection instructions and distance measurement instructions; The instruction protocol design module is further used to: For the query instruction, a forward pulse of a first preset frequency is used as a pilot code, multiple frequencies are combined in pairs to form multiple frequency combinations as information codes, and the multiple frequency combinations are combined with multiple time division strategies to obtain multiple different frequency and time division combinations; For the address coding instruction, a binary frequency shift keying modulation method is adopted, each code element is assigned to one of two preset different frequencies according to its value, and the address coding instruction is set to include a pilot code, an information code and a check code; For the power detection instruction, a forward pulse of a first preset frequency is used as a guide code, and an information code is set using a different frequency, so that the power detection instruction is different from the query instruction; For the ranging instruction, the forward pulse of the first preset frequency is used as the guide code, and multiple frequencies are combined in pairs to form multiple frequency combinations as information codes. The multiple frequency combinations are combined with multiple time division strategies to obtain multiple different frequency division and time division combinations, and signal processing and delay measurement are performed.

9. The underwater acoustic positioning system according to claim 7, characterized in that: The uplink instructions include response instructions and power detection uplink instructions; the response instructions include narrowband signal response instructions and broadband signal response instructions; the broadband signal response instructions include broadband linear frequency modulation signal response instructions and broadband spread spectrum signal response instructions; The instruction protocol design module is further used to: For the narrowband signal response instruction, a forward pulse is used as a reply signal, a signal of a second preset frequency is used as a pilot code, multiple frequencies are combined into multiple frequency combinations by two-by-two combinations to form multiple reply channels, and a total length of the narrowband signal response instruction is set; In response to the broadband linear frequency modulation signal instruction, multiple frequencies are used as center frequencies, and the bandwidth and duration of the signal of each frequency are set; For the broadband spread spectrum signal response instruction, using a pseudo random sequence as the broadband spread spectrum signal response instruction of the transponder; For the power detection uplink instruction, the forward pulse of the second preset frequency is used as the pilot code, and the information code with a preset number of bits is used to represent the transponder power, wherein each code element adopts binary frequency shift keying modulation and a check code is set.

10. The underwater acoustic positioning system according to any one of claims 7 to 9, characterized in that: The signal processing module is further configured to: The frequency domain fast correlation method is used to solve the broadband signal, and the spread spectrum signal recognition method based on code division multiple access is used to detect the broadband signal.

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