Shipborne transceiver used in underwater acoustic positioning system and underwater acoustic positioning system

Abstract

The invention discloses a shipborne transceiver used in an underwater acoustic positioning system and the underwater acoustic positioning system, and relates to the field of offshore oil exploration, the shipborne transceiver comprises a processing unit, a receiving unit, a transmitting unit and a transceiver device; the processing unit comprises a processor and a peripheral circuit thereof; the receiving unit comprises a function selection module, a receiver, a frequency selection module and an analog-digital conversion circuit; the function selection module is used for changing the working environment of the shipborne transceiver and receiving a signal of the transponder through the transceiver; the frequency selection module is used for performing frequency selection processing on the received signal when the received signal is a narrowband signal; the transmitting unit is used for driving the transceiver to transmit signals; the transceiver includes a wireless coil for use in an overwater environment and a transducer for use in an underwater environment. Through two communication modes of electromagnetic induction and underwater sound and corresponding hardware circuits, the shipborne transceiver can well meet the interaction requirements with the transponder in various use scenes.

Description

Technical Field

[0001] The present invention relates to the field of offshore oil exploration, and particularly to an on-board transceiver and an underwater acoustic positioning system used in an underwater acoustic positioning system. Background Art

[0002] In the existing offshore oil exploration technology, on-board transceivers are usually installed on exploration vessels, drilling platforms, etc., mainly providing ranging and positioning functions. As the response end, transponders are usually arranged at fixed points on the seabed or installed on the targets to be positioned. The on-board transceiver emits acoustic pulse signals with specific codes. After receiving the signals from the on-board transceiver, the transponder emits a specific acoustic response signal as the response signal. The on-board transceiver calculates the distance between the on-board transceiver and the transponder, the position of the transponder, etc. according to the time interval between the signal it emits and the received response signal, so as to achieve the ranging and positioning functions. In practical applications, the on-board transceiver and the transponder need to interact information in different usage scenarios, such as interacting in the water environment and interacting in the underwater environment. However, the existing interaction methods between the on-board transceiver and the transponder are difficult to be applicable in different usage scenarios. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed to provide an on-board transceiver and an underwater acoustic positioning system used in an underwater acoustic positioning system that overcome the above problems or at least partially solve the above problems.

[0004] According to one aspect of the embodiments of the present application, an on-board transceiver used in an underwater acoustic positioning system is provided. The on-board transceiver includes: a processing unit, a receiving unit, a transmitting unit, and a transceiver device; Wherein, the processing unit includes a processor and the peripheral circuits of the processor; the processor is used for the conversion between analog signals and digital signals; the peripheral circuits include 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 on-board transceiver and receive the signals from the transponder through the transceiver device; the receiver is used to preprocess the received signals and then select to send the received signals 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 signals when the received signals are narrowband signals; The transmitting unit is used to drive the transceiver device to emit signals for communicating with the transponder; The transceiver device includes a wireless coil for the water environment and a transducer for the underwater environment.

[0005] Further, 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 debounce reset switch circuit; The display screen control circuit is used to drive the display to show the real-time status information of the on-board transceiver; The buzzer drive circuit is used to drive the buzzer to sound when the on-board transceiver successfully receives the transponder feedback after sending an instruction.

[0006] Further, the receiver includes a signal filtering and amplifying circuit and a signal shaping circuit; The signal filtering and amplifying circuit includes a differential amplifying circuit and a fourth-order Butterworth filter; The signal shaping circuit uses a voltage comparator to convert a sine wave into a corresponding square wave.

[0007] Further, the frequency selection module includes a narrowband band-pass filter constructed by multiple groups of capacitors and inductors.

[0008] Further, 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 signals; 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 transmitted signal.

[0009] Further, 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.

[0010] According to another aspect of the embodiments of the present application, an underwater acoustic positioning system is provided, which is characterized by including an instruction protocol design module, a signal processing module, and an on-board transceiver for the underwater acoustic positioning system as described above; The instruction protocol design module is used for: designing protocols for the downlink instructions of the on-board transceiver to the transponder and the uplink instructions of the transponder to the on-board transceiver; wherein, multiple groups of classes are divided for the transponder, and multiple channels are divided for each group class to form multiple transponder combinations; The signal processing module is used for: performing signal processing on the received signal by using a preset algorithm.

[0011] Further, the downlink instructions include an interrogation instruction, an address coding instruction, a power detection instruction, and a ranging instruction; The instruction protocol design module is further used for: For the inquiry instruction, the forward rotation pulse of the first preset frequency is used as the leading code, and multiple frequencies are combined in pairs to form multiple frequency combinations as the information code. The multiple frequency combinations are combined with multiple time division strategies to obtain multiple different frequency division and time division combinations; For the address coding instruction, a binary frequency shift keying modulation method is adopted. Each symbol is assigned to one of two preset different frequencies according to its value, and it is set that the address coding instruction includes a leading code, an information code, and a check code; For the power detection instruction, the forward rotation pulse of the first preset frequency is used as the leading code, and the information code is set using different frequencies so that the power detection instruction is different from the inquiry instruction; For the ranging instruction, the forward rotation pulse of the first preset frequency is used as the leading code, and multiple frequencies are combined in pairs to form multiple frequency combinations as the information code. 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 time delay measurement processing are performed.

[0012] Furthermore, the uplink instructions include 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; The instruction protocol design module is further used for: For the narrowband signal response instruction, the forward rotation pulse is used as the reply signal, the signal of the second preset frequency is used as the leading code, multiple frequencies are combined in pairs into multiple frequency combinations to form multiple reply channels, and the total length of the narrowband signal response instruction is set; For the broadband linear frequency modulation signal response instruction, multiple frequencies are used as the center frequencies, and the bandwidth and duration of the signal of each frequency are set; 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; For the power detection uplink instruction, the forward rotation pulse of the second preset frequency is used as the leading code, the information code with a preset number of bits is used to represent the power of the transponder, where each symbol adopts a binary frequency shift keying modulation method, and a check code is set.

[0013] Furthermore, the signal processing module is further used for: The broadband signal is solved using a frequency domain fast correlation method, and broadband signal detection is performed using a spread spectrum signal recognition method based on code division multiple access.

[0014] According to the technical solution provided by the present invention, for the different usage requirements of the transponder deck and underwater, two types of transceiver devices, namely wireless coils and transducers, are designed respectively. Through two communication methods of electromagnetic induction and underwater acoustic and the corresponding hardware circuits, the on-board transceiver can well meet the interaction requirements with the transponder in various usage scenarios; the on-board 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 whether the narrowband signal arrives is detected 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 rotation pulse without performing complex software processing algorithms, thus effectively reducing the overall power consumption of the machine; combining time division and frequency division technologies, the instruction protocol design of the downlink instructions of the on-board transceiver for the transponder is conveniently completed. The interrogation instructions select a combination of multiple frequency signals and multiple different time division strategies, and different interrogation codes are defined for multiple groups of transponders; the address coding instruction adopts binary frequency shift keying modulation mode, and the reliability of the signal is effectively improved and the interference of multipath is reduced through the combination of the preamble code, information code and check code; in the broadband signal detection, using code division multiple access technology and spread spectrum technology, each transponder is assigned a unique address code, which not only enables them to work simultaneously in the same frequency band without interfering with each other, but also greatly improves the utilization rate 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 order, which not only significantly reduces the calculation amount and memory occupation, but also ensures that the system can meet the requirements of real-time detection, greatly improving the efficiency of the real-time system for processing long sequence data; in order to overcome problems such as multipath effect and acoustic wave attenuation existing when underwater acoustic signals propagate, the on-board transceiver can effectively improve the ranging accuracy of the on-board transceiver and the anti-interference ability of communication through the hardware circuits of the transmitting unit and receiving unit and the detection algorithm design of broadband signals and narrowband signals.

[0015] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the description. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are specifically given below. Brief Description of the Drawings

[0016] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings: Figure 1 The structural block diagram of an on-board transceiver for an underwater acoustic positioning system according to an embodiment of the present application is shown; Figure 2 Shows a schematic diagram of the knob matrix circuit; Figure 3 Shows a schematic diagram of the debounce reset switch circuit; Figure 4 Shows a schematic diagram of the display screen control circuit; Figure 5 Shows a schematic diagram of the buzzer drive circuit; Figure 6 Shows a schematic diagram of the overall power supply architecture of the on-board transceiver; Figure 7 Shows a schematic diagram of the power supply circuit; Figure 8 Shows a schematic diagram of the battery power detection circuit; Figure 9 Shows a schematic diagram of the battery charging protection circuit; Figure 10 Shows a block diagram of the receiving unit; Figure 11 Shows a schematic diagram of the fourth-order Butterworth filter; Figure 12 Shows a schematic diagram of the signal shaping circuit; Figure 13 Shows a schematic diagram of the frequency selection module; Figure 14 Shows a structural diagram of the wireless coil; Figure 15 Shows a block diagram of the transmitting unit; Figure 16 Shows a schematic diagram of the LM386 minimum gain circuit; Figure 17 Shows a schematic diagram of the transmit drive circuit; Figure 18 Shows the anti-dead zone waveform timing diagram; Figure 19 Shows a software design framework diagram of the underwater acoustic positioning system; Figure 20 Shows a schematic diagram of the interrogation instruction; Figure 21 Shows a schematic diagram of the address coding instruction; Figure 22 Shows a schematic diagram of the power detection instruction; Figure 23 Shows a schematic diagram of the narrowband signal response instruction; Figure 24 Shows a schematic diagram of the narrowband signal detection process; Figure 25 Shows the schematic of the fast correlation in the frequency domain Figure 1 ; Figure 26Schematic diagram of fast correlation in the frequency domain is shown Figure 2 ; Figure 27 Schematic diagram of the mathematical model of the spread - spectrum communication transmitter system is shown; Figure 28 Schematic diagram of the process of the ranging function is shown; Figure 29 Schematic diagram of the process of the address coding function is shown; Figure 30 Schematic diagram of the process of the power detection function is shown; Figure 31 Schematic diagram of the process of the self - inspection function of the power of the ship - borne transceiver is shown. Detailed implementation manners

[0017] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the 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. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art.

[0018] Figure 1 Schematic block diagram of a ship - borne transceiver for an underwater acoustic positioning system according to an embodiment of the present application is shown. As Figure 1 shown, the ship - borne transceiver includes: a processing unit 110, a receiving unit 120, a transmitting unit 130, and a transceiver device 140.

[0019] Among them, the processing unit 110 includes a processor 1101 and the peripheral circuits of the processor 1101. The processor 1101 is used for the conversion between analog signals and digital signals. In practical applications, the processor 1101 can select the NUCLEO - U575ZI development board based on the STM32U575 microcontroller. The STM32U575 microcontroller is built - in with a 14 - bit ADC module and a DAC module, which can be used for the conversion between analog signals and digital signals. The peripheral circuits include an operation panel circuit (not shown in the figure), a power supply circuit 1102, a battery power detection circuit 1103, and a battery charging protection circuit 1104.

[0020] Regarding the button configuration of the operation panel, multiple multi - channel knobs and multiple self - reset switch buttons can be selected as the control buttons 1105, such as 4 10 - channel knobs and 3 self - reset switch buttons. Regarding the display 1106, a DDM4 liquid crystal display can be selected. The operation panel is also configured 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 and reset switch circuit. The schematic diagram of the knob matrix circuit is asFigure 2 As shown. The on-board transceiver is also controlled by three self-resetting switch buttons. The button signals can be processed using the hardware debounce chip MAX6816. The schematic diagram of the debounce and reset switch circuit is as Figure 3 shown. The display screen control circuit is used to drive the display to show the real-time status information of the on-board transceiver, such as key parameters like signal strength and operating frequency. The schematic diagram of the display screen control circuit is as Figure 4 shown. The buzzer drive circuit is used to drive the buzzer to sound when the on-board transceiver successfully receives the transponder feedback after sending an instruction. When the on-board transceiver successfully receives the transponder feedback after sending an instruction, the buzzer drive circuit drives the buzzer to emit a clear sound to provide an intuitive auditory confirmation of the operation result. The schematic diagram of the buzzer drive circuit is as Figure 5 shown.

[0021] For various functional requirements, the on-board transceiver uses a convenient operation panel to provide intuitive operation guidance and clear information display, reducing the operation steps. This panel has the function of displaying the input and output results, and can input information in the form of buttons or knobs, effectively ensuring that the operator can easily perform equipment configuration, status monitoring, and data query. The operator can use the knob and buttons to select the working mode of the on-board transceiver and then view the result information through the display.

[0022] Considering that the overall power consumption of the underwater acoustic positioning system does not exceed 50 mA, and other circuits of the underwater acoustic positioning system except the processor 1101 need to be powered by 5V, the power supply circuit 1102 can select the DC-DC (direct current - direct current) conversion chip TPS54331. Figure 6 The schematic diagram of the overall power supply architecture of the on-board transceiver is shown. This diagram clearly shows all the links and components of power management. Among them, the battery voltage VBAT is 12.6V, the power supply of the power supply circuit is 5V, and the power supplies of the processor include 3.3V and 1.8V. Figure 7 The schematic diagram of the power supply circuit is shown, as Figure 7 shown. The output voltage of the power supply circuit can be adjusted externally. The voltage divider network consists of R O1 and R O2 . Formulas (1) and (2) are the output voltage relationships. Set the output voltage to 5V, and use R O1 = 10.2 kΩ, R O2 = 1.91 kΩ.

[0023] Formula (1) Formula (2) Among them, R O1 and R O2 are the two resistors in the voltage divider network, Vref is the reference voltage, V OUT is the output voltage.

[0024] In the power supply circuit, the minimum value of the output inductor is calculated by formula (3). Select the current ripple rate K IND = 0.3. The calculated minimum inductor value is 5.7 μH, and finally an inductor of 6.8 μH is selected.

[0025] Formula (3) where L MIN is the minimum inductor value, V OUT(MAX) is the maximum output voltage, V IN(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 supply chip.

[0026] The minimum capacitance value can be calculated from formula (4).

[0027] Formula (4) where C O(MIN) is the minimum capacitance value, R O is the output load impedance (V O / I O ), F CO(MAX) is the required crossover frequency. So C O can select a ceramic capacitor with a capacitance value of 33 μF, and use two to form a 66 μF capacitor.

[0028] The battery power detection circuit 1103 is used to detect the power of the battery 1107. The battery power detection circuit 1103 can select the LTC4151 chip and communicate with the processor 1101 through the I 2 C bus interface. The schematic diagram of the battery power detection circuit 1103 is as Figure 8 shown.

[0029] For the battery 1107, 3 series-connected and 8 parallel-connected 18650 lithium batteries can be selected as the power supply. The series connection of the batteries increases the total voltage of the batteries to 12.6 V, and the parallel connection increases the total capacitance to 35200 mAh. The battery charging protection circuit 1104 can use the DW01B chip to protect the charging and discharging of the battery 1107, which is used for overcharge and over-discharge protection of single cells. The schematic diagram of the battery charging protection circuit 1104 is as Figure 9 shown. Three DW01B chips can be selected to provide protection for 3 series-connected 18650 lithium batteries.

[0030] The receiving unit 120 of the shipborne transceiver is used to perform preprocessing 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, such as Figure 10 As 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 device 140 includes a wireless coil 1401 for the water environment and a transducer 1402 for the underwater environment. The function selection module 1201 is used to change the working environment of the shipborne transceiver and receive the signal of the transponder through the transceiver device 140. The receiver 1202 is used to perform preprocessing on the received signal and then select to send the received signal to the frequency selection module 1203 or the analog-to-digital conversion circuit 1204 according to the signal form. Among them, when the received signal is a narrowband signal, the received signal is sent to the frequency selection module 1203 for processing. When the received signal is a broadband signal, the received signal 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 when the received signal is a narrowband signal.

[0031] The receiver 1202 includes a signal filtering and amplification circuit and a signal shaping circuit. Among them, the signal filtering and amplification circuit includes a differential amplification circuit and a fourth-order Butterworth filter. The differential amplification circuit can use an SSM2212 chip. The filtering uses a fourth-order Butterworth filter composed 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 as Figure 11 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 use a TLC3702. The schematic diagram of the signal shaping circuit is shown as Figure 12 shown.

[0032] After the shaped signal enters the frequency selection module 1203 through the receiver 1202, 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 band-pass filter constructed by multiple groups of capacitors and inductors. The schematic diagram of the frequency selection module 1203 is shown as Figure 13 shown. Among them, the inductance parameter determines its specific frequency selection characteristics. According to the specified frequency requirements, the selected values of L and C are obtained from the cut-off frequency calculation formula (5) of the capacitor-inductor filter.

[0033] Formula (5) where f0 is the cut-off frequency of the capacitor-inductor filter, L is the inductance, and C is the capacitance.

[0034] It can be calculated that: for signal 1 with a passband of 13 kHz: L1 = 32 mH, C1 = 4700 pF; for signal 2 with a passband of 15 kHz: L2 = 31 mH, C2 = 3600 pF; for signal 3 with a passband of 17 kHz: L3 = 29 mH, C3 = 3000 pF.

[0035] The transceiver device 140 includes a wireless coil 1401 and a transducer 1402. The wireless coil 1401 is used in the water environment, and the transducer 1402 is used in the underwater environment to adapt to two different working environments, namely, above water and underwater. On the water surface, the on-board transceiver exchanges information with the transponder through the wireless coil 1401 in the way of electromagnetic induction; underwater, the on-board transceiver communicates with the transponder through the transducer 1402 by acoustic signals.

[0036] Considering the characteristics of the relatively open water environment and fewer interference factors, in this application, the structure and material selection of the wireless coil 1401 are optimized. In practical applications, the wireless coil 1401 can use 10 turns of copper wire to increase the magnetic flux of the electromagnetic field, and silicone rubber is used for vulcanization reaction to fully ensure its sealing performance. The structural diagram of the wireless coil is as Figure 14 shown.

[0037] As Figure 1 shown, the transmitting unit 130 is mainly responsible for generating and sending signals, specifically for driving the transceiver device 140 to send signals to communicate with the transponder. Among them, 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., D / A circuit). Figure 15 The structural block diagram of the transmitting unit is shown, as Figure 15 shown. Two different 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; the linear power amplifier circuit 1302 is used to drive the wireless coil 1401 to send signals; the transducer communication circuit includes a class-D power amplifier circuit 1304 and a transmitting drive circuit 1305; the class-D power amplifier circuit 1304 is used to drive the transducer 1402 to send signals. The class-D power amplifier circuit 1304 refers to a class-D audio power amplifier, sometimes also called a digital power amplifier circuit; the transmitting drive circuit 1305 is used to perform current enhancement and dead zone processing on the transmitted signal.

[0038] To drive the wireless coil 1401, the linear power amplifier circuit 1302 can use the linear power amplifier LM386. When using LM386, it is configured in 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 as shown in Figure 16 shown.

[0039] The transmit drive circuit 1305 receives the processor 1101, followed by the class-D power amplifier circuit 1304, which performs current enhancement and dead zone processing on the transmit signal. The transmit signal passes through the CD4013B chip, is divided into positive and negative directions, and then transmitted to the MOS transistor driver chip CD54HC40103. The chip guides the signal to the class-D power amplifier circuit, and finally outputs through the power amplifier. The schematic diagram of the transmit drive circuit 1305 is as shown in Figure 17 shown.

[0040] To ensure circuit safety, a small delay adjustment is made to the positive and negative waveforms of the class-D power amplifier circuit 1304. The waveform timing diagram is as shown in Figure 18 shown, where U5-Q2 represents the waveform of pin Q2 of component U5, U5-Q1 represents the waveform of pin Q1 of component U5, U5-Q1’ represents the waveform of pin Q1’ (i.e., Q1-) of component U5, U8-1Y represents the waveform of pin 1Y of component U8, and U8-4Y represents the waveform of pin 4Y of component U8. By introducing a time difference, the simultaneous turn-on of the MOS power transistors is effectively avoided, reducing the risk of circuit conflict.

[0041] The class-D power amplifier circuit 1304 can select IRL8113S as the power transistor and is powered by 12.6V. According to the parameters of the transducer 1402, a sound source level of 180dB required by the index is calculated, which requires a voltage drive of 400V, while the drain-source voltage is 25V. Thus, the transformer turns ratio is: Formula (6) where n is the transformer turns ratio, U L is the required voltage, and U i is the drain-source voltage.

[0042] In this application, the processor is always in the powered-on state, and the transmit unit and the transceiver device are in the standby low-power state. The overall power consumption of the shipborne transceiver is no more than 50mA when the class-D power amplifier does not transmit, effectively reducing the power consumption of the shipborne transceiver and extending its standby time. To overcome problems such as multipath effects and acoustic wave attenuation during the propagation of underwater acoustic signals, the shipborne transceiver can effectively improve the ranging accuracy and anti-interference ability of communication through the hardware circuits of the transmit unit and the receive unit and the detection algorithm design of broadband signals and narrowband signals.

[0043] The present invention also provides an underwater acoustic positioning system, which includes an instruction protocol design module, a signal processing module, and the on-board transceiver for the underwater acoustic positioning system as described above. Among them, the instruction protocol design module is used for: designing the protocols for the downlink instructions of the on-board transceiver to the transponder and the uplink instructions of the transponder to the on-board transceiver; wherein, multiple types of transponder groups are divided, and multiple channels are divided for each type of group, constituting multiple transponder combinations; the signal processing module is used for: performing signal processing on the received signals by using a preset algorithm.

[0044] According to the working functions of the on-board transceiver, the software structure of the underwater acoustic positioning system can be divided into four main parts: ranging, address coding, power detection, and on-board transceiver power detection. The overall software structure is organized into a framework diagram, as Figure 19 shown. When the system is ready, it receives the button instruction; the transceiver device is determined; if the working environment is an underwater environment, an interrogation signal is transmitted through the transducer; if the working environment is an above-water environment, an interrogation signal is transmitted through the wireless coil; the ADC polls and receives, and determines whether the received signal is correct; if it is correct, the instruction type is determined; if it is incorrect, the display gives a failure prompt; when it is determined through the instruction type that it belongs to the response function, response detection is performed, the display gives a success prompt, and the buzzer sounds; when it is determined through the instruction type that it belongs to the ranging function, the distance is calculated, and the display shows the distance; when it is determined through the instruction type that it belongs to the identification code encoding (i.e., address coding) function, response detection is performed, the display gives a success prompt, and the buzzer sounds; when it is determined through the instruction type that it belongs to the power detection function, the power is calculated, and the display shows the voltage; if it is determined by the transceiver device that the working environment is inside the system, the on-board transceiver power is detected, the voltage is measured, and the display shows the voltage. To implement these functions, the overall software design is divided into several parts: instruction protocol design, signal processing algorithm, and system software implementation.

[0045] For example, in the protocol designed for the underwater acoustic positioning system, the transponders are divided into 128 different types of groups, and each type of group is further subdivided into 8 different channels, totaling 1024 transponder combinations, which can achieve the cooperative target positioning function of 1024 transponders.

[0046] The downlink instructions include the instruction protocols for implementing various functions, specifically including interrogation instructions, address coding instructions, power detection instructions, and ranging instructions.

[0047] The instruction protocol design module is further used for: for the inquiry instruction, using the forward rotation pulse of the first preset frequency as the pilot code, forming multiple frequency combinations as the information code by pairwise combination of multiple frequencies, and combining the multiple frequency combinations with multiple time division strategies to obtain multiple different frequency division and time division combinations; for the address coding instruction, adopting binary frequency shift keying modulation, each symbol is assigned to one of two preset different frequencies according to its value, and it is set that the address coding instruction includes a pilot code, an information code and a check code; for the power detection instruction, using the forward rotation pulse of the first preset frequency as the pilot code, setting the information code with different frequencies so that the power detection instruction is different from the inquiry instruction; for the ranging instruction, using the forward rotation pulse of the first preset frequency as the pilot code, forming multiple frequency combinations as the information code by pairwise combination of multiple frequencies, combining the multiple frequency combinations with multiple time division strategies to obtain multiple different frequency division and time division combinations, and performing signal processing and time delay measurement processing.

[0048] Specifically, the inquiry instruction uses four frequencies f1, f2, f3 and f4, where the frequency f1 is the first preset frequency. The forward rotation pulse (i.e., CW pulse) of f1 is used as the pilot code to notify the transponder of the arrival of the inquiry signal. Subsequently, three different frequency combinations are formed by pairwise combination of the remaining three frequencies as the information code (or called information code chips). By combining these frequency combinations with 43 different time division strategies, a total of 128 different frequency division and time division combinations can be obtained. The schematic diagram of the inquiry instruction is as Figure 20 shown. The total length of the inquiry instruction can be τ. The inter-symbol interval a starts from τ1 and increases by 5 ms each time; the inter-symbol interval b starts from τ2 and decreases by 5 ms each time, and there are 43 changes in the time division protocol. The ranging instruction is the same as the inquiry instruction, except that signal processing and time delay measurement work are further carried out.

[0049] The address coding instruction adopts binary frequency shift keying (BFSK) modulation, and each symbol is assigned to one of two preset different frequencies according to its value (0 or 1). To improve the reliability of the signal and reduce the influence of multipath interference, each group of address coding instructions can include three parts: a pilot code, an information code and a check code. The schematic diagram of the address coding instruction is as Figure 21 shown. The last check code in the address coding instruction determines the accuracy of the signal through parity check. If the sum is odd, the check code is set to 1; if the sum is even, the check code is set to 0.

[0050] The power detection instruction uses the CW pulse of f1 as the pilot code, 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 inquiry instruction. The schematic diagram of the power detection instruction is as Figure 22 shown.

[0051] The uplink commands mainly include the response command and the power detection uplink command. The ranging uplink command and the address coding uplink command are the same as the response command. Among them, the uplink commands include the response command and the power detection uplink command; the response command includes the narrowband signal response command and the broadband signal response command. The instruction protocol design module is further configured to: for the narrowband signal response command, use the forward rotation pulse as the response signal, use the signal of the second preset frequency as the pilot code, form multiple response channels by combining multiple frequencies in pairs to form multiple frequency combinations, and set the total length of the narrowband signal response command. For example, the narrowband signal response command uses a CW pulse as the response signal, the frequency f11 is the second preset frequency, and the signal of the frequency f11 is used as the pilot code. Then, the 5 frequencies f12, f13, f14, f15, and f16 are combined in pairs into 8 groups to form 8 different response channels. Figure 23 shows a schematic diagram of the narrowband signal response command, such as Figure 23 shown, the total length of the narrowband signal response command is fixed at τ, the inter-symbol interval a is τ1, and the inter-symbol interval b is τ2.

[0052] The broadband signal response command includes the broadband linear frequency modulation signal response command and the broadband spread spectrum signal response command. The instruction protocol design module is further configured to: for the broadband linear frequency modulation signal response command, use multiple frequencies as the center frequencies, and set the bandwidth and duration of the signal of each frequency; for the broadband spread spectrum signal response command, use the pseudo-random sequence as the broadband spread spectrum signal response command of the transponder.

[0053] For example, for the broadband linear frequency modulation signal response command, 8 different frequencies can be used as the center frequencies, and the signal of each frequency has a bandwidth of 2 kHz and a duration of τ0. For the broadband spread spectrum signal response command, a 127-bit long Gold sequence generated by a 7th-order m-sequence can be selected as the broadband spread spectrum signal response command of the transponder, and 8 balanced Gold sequences are selected from them.

[0054] The instruction protocol design module is further configured to: for the power detection uplink command, use the forward rotation pulse of the second preset frequency as the pilot code, use the information code of the preset number of bits to represent the power of the transponder. Among them, each symbol uses binary frequency shift keying modulation, and the check code is set. The power detection uplink command also uses binary frequency shift keying modulation. The CW pulse of the frequency f11 is used as the pilot code, and then 10-bit information code is used to represent the power of the transponder. Among them, each symbol uses BFSK modulation, the 0 symbol corresponds to f12, and the 1 symbol corresponds to f13; the last check code determines the accuracy of the signal through parity check.

[0055] In a shipborne transceiver, the detection of narrowband signals is implemented through a hardware circuit. By the level status of the GPIO interface, it is detected whether a signal arrives. Specifically, the processor in the processing unit of the shipborne transceiver is connected to the output end of the frequency selection module, and whether a narrowband signal arrives is detected by the level status of the GPIO interface. Figure 24 The flow schematic diagram of narrowband signal detection is shown. As Figure 24 shown, the transceiver device receives a signal; the receiver receives a signal; it is judged whether the frequency selection network recognizes a 33 kHz pilot code; if the 33 kHz pilot code is recognized, it is sent to the processor GPIO, and the processor determines it as a single-frequency signal and prepares to judge other processor GPIOs of the frequency selection network, and then judges whether the first information code is received; if the first information code is received, it continues to judge whether the second information code is received; if the second information code is received, it judges whether the time delay is accurate, and if the time delay is accurate, it judges that the transponder response is successful; if the first information code is not received, or the second information code is not received, or the time delay is inaccurate, it judges that the transponder response fails; if the 33 kHz pilot code is not recognized, the processor AD is accessed to start data acquisition and other forms of signal detection are performed.

[0056] When the frequency selection network recognizes the pilot code, it will open the GPIO interfaces of all frequencies and set them to the input state. Then a timer is used for precise time control. When the interval from the leading edge of the pilot code is 100 ms, the shipborne transceiver will start window detection. When the interval from the leading edge of the pilot code is τ, the shipborne transceiver will perform window detection again. In this way, the frequencies and arrival times of the pilot code and the two information codes can be determined. This recognition method not only improves the accuracy of signal reception but also helps to reduce the influence of environmental multipath on signal reception.

[0057] Due to the time-bandwidth product characteristic of the broadband linear frequency modulation signal, the time resolution can be improved through pulse compression technology. In order to improve the precise recognition ability of the arrival time of the interrogation signal, the present application adopts the correlation method to solve the broadband signal. The signal processing module is further used for: solving the broadband signal by using the fast correlation method in the frequency domain and detecting the broadband signal by using the spread spectrum signal recognition method based on code division multiple access.

[0058] In the detection of broadband signals, the copy correlator adopts a discrete form during processing. Assuming two causal signals x(n) and y(n), to calculate the correlation between the two signals x(n) and y(n), the strategy of convolution calculation can be adopted. In the present application, the signal processing module can use frequency domain multiplication to perform convolution operation, which transforms the signal to the frequency domain through FFT and then returns it to the time domain through IFFT. For an L-length sequence x(n) and an M-length y(n), its linear convolution expression is: Formula (7) Among them, z(n) is the output sequence, y(l) is the reference signal 1, x(n - l) is the reference signal 2, and M is the length of the y(n) sequence.

[0059] Then the length of z(n) is L + M - 1. When the circular convolution is to be equal to the linear convolution, the aliasing situation in the frequency domain can be avoided. Taking N ≥ L + M - 1, we get: Formula (8) Formula (9) The specific expressions after that are as follows: Formula (10) Formula (11) Formula (12) Formula (13) Figure 25 Shows the schematic of fast correlation in the frequency domain Figure 1 , as Figure 25 shown, first, the y(n) sequence is flipped and the N-point FFT is calculated to obtain Y(k). Then, the N-point FFT is calculated for the sequence x(n) to obtain X(k). Z(k) is obtained through multiplication operation, and the N-point IFFT operation is performed on Z(k) to obtain z(n).

[0060] In the signal processing of a real-time system, when faced with the situation of needing to perform fast correlation calculation in the frequency domain between a long input sequence x(n) and a short reference signal y(n), direct processing will cause a sharp increase in the demand for computing resources due to the large amount of zero-padding required for y(n). Figure 26 Shows the schematic of fast correlation in the frequency domain Figure 2 , in this application, the overlapping save method is proposed to perform 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, M - N zeros are added after y(n) to obtain y N (n), and the expression of N is N = 2 k ≥ L + M - 1. Then, N - L zeros are added in front of the first sequence after being divided into L lengths, and then its frequency domain fast correlation is performed with y N (n) to obtain the N-point correlation output. The first M - 1 points are discarded, and the remaining part is retained. Then, the retained parts are combined each time to obtain the output sequence z(n).

[0061] 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 real-time signal processing requirements. Assume the length of the reference signal is N, which is extended to 2N points by adding zeros. The buffer is set to N, and two buffers are set in total. The overlap-save method is adopted. Then, the first N points of the two buffers are linked to the last N points of the previous buffer, and the next N points are the new data collected by the current buffer. Then, the data in each buffer is correlated with the local signal, and the last N points of the correlation result are retained as the correlation output sequence. The fast sliding correlation scheme of this system effectively improves the data processing speed and ensures that the underwater acoustic positioning system can achieve efficient real-time signal detection and processing.

[0062] When the processor performs copy correlation calculation 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.

[0063] In the broadband signal detection of this application, the spread spectrum signal recognition based on code division multiple access (CDMA) technology is introduced. This technology allows multiple users to communicate simultaneously in the same frequency band through unique pseudo-random sequence codes assigned to each user. The pseudo-random sequence can be used in spectrum spreading and is called the spread spectrum code sequence. Figure 27 The schematic diagram of the mathematical model of the spread spectrum communication transmitter system is shown as Figure 27 shown, and the expression of its output signal is: Formula (14) where f0 is the carrier center frequency, 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 d(t) and c(t) in are the spread spectrum code waveforms.

[0064] Satisfying Formula (14), using d(t) to represent the encoded data stream {a n}, then the transmitted signal s(t) is: Formula (15) In this application, the Gold sequence is adopted as the pseudo-random sequence. The protocol selects 8 balanced Gold sequences with a length of 127 bits generated by 7th-order m sequences as the broadband spread spectrum signal response instructions of the transponder. The modulation carrier frequency is 24 kHz, which has the characteristics of excellent autocorrelation and low cross-correlation value. The balanced Gold sequence has excellent autocorrelation and zero cross-correlation, and is suitable as the broadband spread spectrum signal response instruction of the transponder.

[0065] Combined with the above introductions of the hardware and software, the implementation processes of various functions of the underwater acoustic positioning system of this application are introduced as follows.

[0066] The ranging function is that during the interrogation and response process, the shipborne transceiver sends an interrogation command to the transponder, and then polls the ADC to wait for the response signal of the transponder. Then, the time difference between sending the interrogation command and receiving the response signal is measured, so that the underwater acoustic positioning system can calculate the distance of signal propagation. Figure 28 The flow schematic diagram of the ranging function is shown, as Figure 28 shown. After receiving the ranging command, the transmitter (i.e., the transceiver device) transmits the interrogation command, and the signal processing receives the response signal. If the response is successful, the distance is calculated and displayed on the display; if the response fails, the display shows failure.

[0067] In the underwater acoustic positioning system, the address coding function is mainly used for the deployment work of the transponder. It not only uses the interrogation and response function, but also requires knob input and screen control to enhance user interactivity and the intuitiveness of operation. Through the knob matrix, the operator can easily set or adjust the address of the transponder, and the screen control function displays the operation feedback and the configuration status of the address in real time. The address coding function simplifies the transponder deployment process and improves the user experience of the communication system. Figure 29 The flow schematic diagram of the address coding function is shown, as Figure 29 shown. After receiving the address coding command, read the digital identity code of the knob, generate a 10-bit information code according to the number; transmit the coding command for the first time and the second time; the transmitter transmits the interrogation command, 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.

[0068] The battery power detection function is to decode the narrowband signal to obtain the battery power information of the transponder. It uses a frequency selection network to detect and analyze the signal to extract the 10-bit information code and 1-bit check code sent by the transponder. These 10-bit information codes contain the numerical information of the transponder battery power, and the check code is used to ensure the integrity and accuracy of the received data. Figure 30 The flow schematic diagram of the battery power detection function is shown, as Figure 30 shown. After receiving the battery power detection command, transmit the battery power detection command; use the frequency selection network to detect and analyze the signal to extract each information code and check code; sequentially detect whether each information code is correct, whether the time delay is correct, and whether the check code is correct; if any information code is incorrect or the time delay is incorrect or the check code is incorrect, the display shows that the battery power detection fails; if each information code, time delay, and check code are all correct, calculate the battery power and display the battery power on the display screen.

[0069] The power self - inspection function of the ship - borne transceiver is realized by monitoring the power status of the device in real - time. This function first performs button polling to confirm the initiation of power self - inspection. After receiving the ship - borne transceiver power self - inspection instruction, through the I 2 C bus, it connects the battery power detection circuit to the processor to start the ship - borne transceiver power self - inspection. Subsequently, the battery detection IC starts the voltage acquisition program, calculates the voltage value, and the display shows the voltage value. The flow schematic diagram of the ship - borne transceiver power self - inspection function is as Figure 31 shown.

[0070] According to the technical solutions provided by the embodiments of the present application, for the different usage requirements of the transponder on the deck and underwater, two types of transceiver devices, namely wireless coils and transducers, are respectively designed. Through two communication methods, electromagnetic induction and underwater acoustic, and the corresponding hardware circuits, the ship - borne transceiver can well meet the interaction requirements with the transponder in various usage scenarios; the ship - borne transceiver adopts a frequency - selection module that can conveniently complete the detection of narrow - band signals. The processor is connected to the output end of the frequency - selection module, and through the level status of the GPIO interface, it detects whether the narrow - band signal arrives. During the detection process, the processor only needs to use a timer to determine the arrival time of each positive - rotation pulse, without the need for complex software processing algorithms, thus effectively reducing the overall power consumption of the machine; combining time - division and frequency - division technologies, it conveniently completes the design of the instruction protocol for the downlink instructions of the ship - borne transceiver to the transponder. The interrogation instruction selects a combination of multiple frequency signals and multiple different time - division strategies, and defines different interrogation codes for multiple groups of transponders; the address - coding instruction adopts binary frequency - shift keying modulation. Through the combination of the preamble code, information code, and check code, it effectively improves the reliability of the signal and reduces the interference of multipath; in the broadband signal detection, using code - division multiple access technology and spread - spectrum technology, each transponder is assigned a unique address code. This not only enables them to work simultaneously in the same frequency band without mutual interference, but also greatly improves the utilization rate of the frequency band; adopting the fast sliding correlation signal processing method to perform frequency - domain correlation on each subsequence separately, and finally synthesizing the correlation results of each subsequence in order into a complete correlation sequence, not only significantly reduces the amount of calculation and memory occupancy, but also ensures that the system can meet the requirements of real - time detection, greatly improving the efficiency of the real - time system for processing long - sequence data; in order to overcome problems such as multipath effects and acoustic wave attenuation during the propagation of underwater acoustic signals, the ship - borne transceiver can effectively improve the ranging accuracy of the ship - borne transceiver and the anti - interference ability of communication through the hardware circuits of the transmitting unit and receiving unit and the design of the broadband signal and narrow - band signal detection algorithms.

[0071] The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. A variety of general-purpose systems can also be used in conjunction with the teachings provided herein. The structure required to construct such systems will be apparent from the above description. Additionally, the present invention is not directed to any particular programming language. It should be understood that the teachings of the present invention described herein can be implemented in a variety of programming languages, and the description of a particular language above is for the purpose of disclosing the best mode of the present invention.

[0072] In the specification provided herein, numerous specific details are set forth. 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 have not been shown in detail so as not to obscure the understanding of this specification.

[0073] Similarly, it should be understood that, in order to streamline this disclosure and assist in understanding one or more of the various inventive aspects, in the foregoing description of exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, the disclosed method should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the claims reflect, the inventive aspects lie in less than all the features of the preceding single embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the present invention.

[0074] Those skilled in the art will appreciate that the modules in the devices in the embodiments can be adaptively changed and disposed in one or more devices different from those of the embodiments. The modules or units or components in the embodiments can be combined into one module or unit or component, and in addition, they can be divided into multiple sub-modules or sub-units or sub-components. Except that at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all the features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all the processes or units of any method or device so disclosed. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) can be replaced by an alternative feature that provides the same, equivalent, or similar purpose.

[0075] In addition, those skilled in the art will understand that, although some embodiments described herein include certain features included in other embodiments rather than other features, the combination of features of different embodiments is meant to be within the scope of the present invention and forms different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0076] Each component embodiment of the present invention can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) can be used in practice to implement some or all of the functions of some or all of the components according to the embodiments of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program for implementing the present invention can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier signal, or in any other form.

[0077] It should be noted that the above embodiments illustrate the present invention rather than limit the present invention, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In a unit claim listing several devices, several of these devices can be embodied by the same item of hardware. The use of the words first, second, and third, etc. does not denote any order. These words can be interpreted as names.

Claims

1. A shipborne transceiver for an underwater acoustic positioning system, characterized in that, The on-board transceiver includes: a processing unit, a receiving unit, a transmitting unit, and a transceiver device; Among them, the processing unit includes a processor and the peripheral circuits of the processor; the processor is used for the conversion between analog signals and digital signals; the peripheral circuits include 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 on-board transceiver and receive the signal of the transponder through the transceiver device; the receiver is used to preprocess the received signal and then select to send the received signal 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 signals for communication with the transponder; The transceiver device includes a wireless coil for the water environment and a transducer for the underwater environment.

2. The shipborne transceiver for an underwater acoustic positioning system according to claim 1, wherein 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 debounce reset switch circuit; The display screen control circuit is used to drive the display to display the real-time status information of the on-board transceiver; The buzzer drive circuit is used to drive the buzzer to sound when the on-board transceiver successfully receives the feedback of the transponder after sending an instruction.

3. The shipborne transceiver for an underwater acoustic positioning system according to claim 1, wherein The receiver includes a signal filtering and amplifying circuit and a signal shaping circuit; The signal filtering and amplifying circuit includes a differential amplifying circuit and a fourth-order Butterworth filter; The signal shaping circuit uses a voltage comparator to convert a sine wave into a corresponding square wave.

4. The shipborne transceiver for an underwater acoustic positioning system according to claim 1, wherein, The frequency selection module includes a narrowband band-pass filter constructed by multiple groups of capacitors and inductors.

5. The shipborne transceiver for an underwater acoustic positioning system according to claim 1, wherein, 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 signals; The transducer communication circuit includes a class D power amplifier circuit and a transmission drive circuit; the class D power amplifier circuit is used to drive the transducer to transmit signals; the transmission drive circuit is used to perform current enhancement and dead zone processing on the transmission signal.

6. The shipborne transceiver for an underwater acoustic positioning system according to any one of claims 1-5, 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 includes an instruction protocol design module, a signal processing module, and an on-board transceiver for an underwater acoustic positioning system as described in any one of claims 1-6; The instruction protocol design module is used for: designing protocols for the downlink instructions of the on-board transceiver to the transponder and the uplink instructions of the transponder to the on-board transceiver; among them, multiple groups of classes are divided for the transponder, and multiple channels are divided for each group class to form multiple transponder combinations; The signal processing module is used for: performing signal processing on the received signal by using a preset algorithm.

8. The underwater acoustic positioning system according to claim 7, wherein The downlink instructions include an inquiry instruction, an address coding instruction, a power detection instruction, and a ranging instruction; The instruction protocol design module is further configured to: For the inquiry instruction, use the forward rotation pulse of the first preset frequency as the pilot code, form multiple frequency combinations as the information code by combining multiple frequencies in pairs, and 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, adopt binary frequency shift keying modulation, and each symbol is assigned to one of two preset different frequencies according to its value, and set that the address coding instruction includes a pilot code, an information code, and a check code; For the power detection instruction, use the forward rotation pulse of the first preset frequency as the pilot code, and set the information code with different frequencies so that the power detection instruction is different from the inquiry instruction; For the ranging instruction, use the forward rotation pulse of the first preset frequency as the pilot code, form multiple frequency combinations as the information code by combining multiple frequencies 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 for time delay measurement; 9. The underwater acoustic positioning system according to claim 7, characterized in that The uplink instructions include 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; The instruction protocol design module is further configured to: For the narrowband signal response instruction, use the forward rotation pulse as the reply signal, use the signal of the second preset frequency as the pilot code, form multiple reply channels by combining multiple frequencies in pairs, and set the total length of the narrowband signal response instruction; For the broadband linear frequency modulation signal response instruction, use multiple frequencies as the center frequencies, and set the bandwidth and duration of the signal of each frequency; For the broadband spread spectrum signal response instruction, use a pseudo-random sequence as the broadband spread spectrum signal response instruction of the transponder; For the power detection uplink instruction, use the forward rotation pulse of the second preset frequency as the pilot code, use an information code with a preset number of bits to represent the power of the transponder, where each symbol adopts binary frequency shift keying modulation, and set a check code; 10. The underwater acoustic positioning system according to any one of claims 7-9, characterized in that, The signal processing module is further configured to: Solve the broadband signal using the fast correlation method in the frequency domain, and perform broadband signal detection using the spread spectrum signal recognition method based on code division multiple access.

Images