Hardware-in-the-loop automatic performance test method and system for underwater acoustic communication set

Abstract

The invention provides a hardware-in-the-loop automatic performance test method and system for an underwater acoustic communication set, and solves the technical problems that when the performance of the underwater acoustic communication set is measured in the prior art, the underwater environment cannot be completely separated, and external interference is introduced, so that a simulation signal is unstable, and a test error is caused. The method comprises the following steps: acquiring an environment file, and generating an underwater acoustic channel by using a simulation model to obtain an impulse response; acquiring a transmitting signal of the underwater acoustic communication set, performing down-conversion, then performing convolution with the impulse response to obtain convolution data, and performing up-conversion to obtain an output signal; transmitting back to the underwater acoustic communication set, reading a demodulation result of the underwater acoustic communication set, calculating an error rate, judging whether iteration is completed or not, and if so, drawing a performance curve; otherwise, continuously controlling the underwater acoustic communication set to transmit the signal for testing. The method can be widely applied to the technical field of underwater acoustic communication.

Description

Technical Field

[0001] The present application belongs to the field of underwater acoustic communication technology, and more specifically, relates to a hardware-in-the-loop automated performance testing method and system for underwater acoustic communication equipment. Background Art

[0002] As a crucial means of underwater wireless communication, underwater acoustic communication plays an irreplaceable role in marine scientific research, underwater resource exploration, underwater navigation and positioning. However, due to the complexity and variability of the underwater ocean environment, the development of underwater acoustic communication technology and the performance evaluation of communication equipment have always faced numerous challenges. Traditional testing methods typically require testing in a real underwater ocean environment. This approach is not only costly, but also difficult to precisely control test conditions and reproduce environmental variables, making it impossible to comprehensively and accurately evaluate the performance of communication equipment.

[0003] An existing Chinese invention patent, publication number CN108270499A, discloses an underwater acoustic communication performance testing device and method. This method tests the communication performance of an underwater acoustic communication device by constructing a simulator that approximates a real ocean underwater acoustic channel. This allows for a comprehensive and objective third-party assessment of the device's performance in a water tank. However, this patented method achieves measurement by placing the underwater acoustic transducer in the device underwater. This measurement method cannot be completely separated from underwater measurements, resulting in interference with the simulated channel and measurement errors due to the influence of the tank's size, temperature, and shape. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a hardware-in-the-loop automated performance testing method and system for underwater acoustic communication equipment, so as to solve the technical problem in the prior art that when measuring the performance of underwater acoustic communication equipment, it is impossible to completely separate from the underwater environment, and external interference is introduced to make the simulation signal unstable, resulting in test errors.

[0005] To achieve the above-mentioned purpose, a first aspect of an embodiment of the present application provides a hardware-in-the-loop automated performance testing method for an underwater acoustic communication device, comprising the following steps: obtaining an environment file, importing a simulation model to generate an underwater acoustic channel to obtain an impulse response; Obtain the transmit signal of the underwater acoustic communication device, perform down-conversion, convolve it with the impulse response to obtain convolution data, and perform up-conversion to obtain the output signal; Input it back to the underwater acoustic communication machine, read the demodulation result of the underwater acoustic communication machine, calculate the bit error rate, and judge whether the iteration is completed. If so, draw the performance curve; otherwise, continue to control the underwater acoustic communication machine to transmit the signal for testing.

[0006] Preferably, the impulse response convolution formula is as follows: ; Where, is the convolution data, is the impulse response, is the signal processed by the low-pass filter, is a discrete time variable, is the delay index in the discrete-time system.

[0007] Preferably, the process of obtaining the impulse response includes: calculating a beam according to a beam width and a beam curvature, converting the beam to obtain an acoustic beam, and superimposing all acoustic beams reaching the target to calculate the impulse response.

[0008] Preferably, the formula for calculating the beam according to the beam width and beam curvature is as follows: ; ; Where, is the beam width, is the beam curvature, p is the differential form of p(s), q is the differential form of q(s), is the local sound speed along the ray path, is the arc length along the ray, The speed of sound The second-order derivative in the direction normal to the sound path can be written as: ; Where, is the radial coordinate, is the distance perpendicular to the main sound line, is the vertical coordinate, is the normal vector of the sound ray, which can be written as:

[0009] Where, is the radial component in the normal direction of the sound path, is the vertical component in the normal direction of the sound path; The beams are: ; Where, For the beam, is an arbitrary constant, is the distance perpendicular to the main sound line, is the angular frequency of the sound source, is the imaginary unit, The arc length of the sound wave propagating from the sound source to the The cumulative time required for the position.

[0010] Preferably, the impulse response formula is as follows: ; Where, is the beam number, For the The sound beam The weighting coefficient of time, For the The sound beam The propagation delay of time, is the unit impulse response, is the delay index in the discrete-time system.

[0011] Preferably, before obtaining the transmission signal of the underwater acoustic communication device, it is necessary to input the interface type, control signal format, transmission signal parameters and result display parameters of the underwater acoustic communication device.

[0012] Preferably, before down-conversion, the transmission signal needs to be determined whether it is a digital signal. If it is a digital signal, it is directly down-converted; otherwise, it needs to be amplified, filtered, and converted into a digital signal before down-conversion.

[0013] A second aspect of the embodiments of the present application provides a hardware-in-the-loop automated performance testing system for an underwater acoustic communication device, comprising a power supply module, a main processing module, a signal processing module, and a human-computer interaction module connected to the power supply module; The main processing module obtains the environment file based on the input of the human-computer interaction module and the signal processing module, imports the simulation model to generate the underwater acoustic channel to obtain the impulse response; obtains the transmission signal of the underwater acoustic communication machine, performs down-conversion and convolves it with the impulse response to obtain the convolution data, and performs up-conversion to obtain the output signal; inputs it back to the underwater acoustic communication machine, reads the demodulation result of the underwater acoustic communication machine, calculates the bit error rate, and determines whether the iteration is completed. If so, draws the performance curve; otherwise, continues to control the underwater acoustic communication machine to transmit the signal for testing.

[0014] Preferably, the input of the human-computer interaction module includes the interface type, control signal format, transmission signal parameters and result display parameters of the underwater acoustic communication device; The main processing module includes an FPGA unit and an ARM unit, and the signal processing module includes a programmable amplifier, an analog-to-digital converter, a digital-to-analog converter and a low-pass filter.

[0015] Preferably, the underwater acoustic communication machine is controlled by controlling the signal format to send the demodulation result to the human-computer interaction module for judgment via the serial port or network port.

[0016] The beneficial effects of the present application are as follows: the present application proposes a hardware-in-the-loop automated performance testing method and system for underwater acoustic communication devices, which utilizes a simulation model to generate an underwater acoustic channel based on an acquired environmental file, thereby simulating the underwater acoustic channel. The performance of the underwater acoustic communication device can be tested without actually entering the underwater environment, thus avoiding the time-consuming and labor-intensive process of multiple round trips to the ocean environment for testing, and ensuring that the simulated underwater acoustic channel will not be interfered with by the external environment, thereby ensuring the accuracy of the test results. After acquiring the transmit signal of the underwater acoustic communication device, the transmit signal is down-converted, and then the processed transmit signal is convolved with the impulse response of the underwater acoustic channel to accurately simulate the propagation process of the transmit signal in the underwater acoustic channel, so that the obtained convolution data can reflect the influence of the actual channel on the signal, providing more realistic convolution data, and making the performance of the tested underwater acoustic communication device more accurate. The convolution data is then up-converted and input back to the underwater acoustic communication machine. The demodulation result of the underwater acoustic communication machine is read, and the performance of the underwater acoustic communication machine is automatically judged based on the bit error rate of the demodulation result. The performance curve is drawn to more intuitively show the performance of the underwater acoustic communication machine in each test, completing the hardware-in-the-loop automated test.

[0017] In summary, the hardware-in-the-loop automated performance testing method and system for underwater acoustic communication equipment proposed in this application not only solves the problem that traditional testing cannot completely escape the underwater environment, and introduces external interference that makes the simulation signal unstable and leads to test errors, but also realizes automated testing of hardware in the loop and significantly improves the accuracy of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 A schematic diagram of the overall process of a hardware-in-the-loop automated performance testing method for an underwater acoustic communication device provided in one embodiment of the present application; Figure 2 An entity relationship diagram of an underwater acoustic environment database provided in one embodiment of the present application; Figure 3 A schematic diagram of the structure of a hardware-in-the-loop automated performance testing system for underwater acoustic communication equipment provided in one embodiment of the present application; Figure 4 A schematic diagram of the structure of a programmable amplifier provided in one embodiment of the present application; Figure 5 A schematic diagram of the structure of an analog-to-digital converter provided in one embodiment of the present application; Figure 6 A schematic structural diagram of a digital-to-analog converter provided in one embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0021] This application provides a hardware-in-the-loop automated performance testing method and system for underwater acoustic communication devices. This method abandons the traditional method of placing the underwater acoustic transducer in an underwater environment such as the ocean or a pool for measurement. Instead, it uses a simulation model, the Bellhop model, to generate an underwater acoustic channel and simulate the underwater acoustic environment to test the performance of the underwater acoustic communication device. This method, which allows the performance of the underwater acoustic communication device to be tested without actually entering the underwater environment, avoids the time-consuming and labor-intensive process of multiple round trips to the ocean environment for testing and ensures that the simulated underwater acoustic channel is not interfered with by the pool environment. Furthermore, this application can customize the environment file, the interface type of the tested underwater acoustic communication device, the control signal format, the transmission signal parameters, and the result display parameters, and use them as the basis for subsequently controlling the underwater acoustic communication device's transmission signal, sending the demodulation results, and judging the performance of the demodulation results. This method of simulating the underwater acoustic channel effectively reduces the interference of the pool on the underwater acoustic channel and ensures the stable transmission of the transmission signal. Setting the result display parameters allows for determining the bit error rate of the demodulation results in the underwater acoustic communication device, thereby testing the performance of the underwater acoustic communication device. This not only achieves the goal of testing outside the underwater environment, but also ensures the accuracy and reliability of the measured performance results. Therefore, the present application provides a hardware-in-the-loop automated performance testing method and system for underwater acoustic communication devices, effectively preventing external interference with the analog channel and more accurately evaluating the performance of the underwater acoustic communication device.

[0022] See also Figure 1 , which is a hardware-in-the-loop automated performance testing method for underwater acoustic communication equipment provided in the first embodiment of the present application. It includes the following steps: S1: Obtain the environment file, import it into the simulation model to generate the underwater acoustic channel and obtain the impulse response.

[0023] Before testing, the test system inputs must be initialized, including system startup and hardware module self-tests. After initialization, the user sets a custom underwater acoustic environment or a preset underwater acoustic environment to obtain the environment file.

[0024] If you customize the underwater acoustic environment to obtain the environment file, you need to enter the simulation environment parameters yourself, including the position and movement speed of the underwater acoustic transmitter under test in the set environment; the number and emission angle of the underwater acoustic transducers; the position, movement speed and number of the underwater acoustic receiver under test; the water body conditions, seabed shape, sea surface shape, top and bottom reflection coefficients, sound velocity profile data, wind speed, etc., to generate the environment file.

[0025] If you choose to preset the underwater acoustic environment to obtain the environment file, the existing environment file will be called from the underwater acoustic environment database to simulate the real underwater communication channel. The underwater acoustic environment database uses the open source embedded SQLite database engine written in C language. It is lightweight, fast, and supports cross-platform operation. The preset environment parameters are derived from the World Ocean Depth Chart (GEBCO), Earth Topography Data (ETOPO), World Ocean Database (WOD), etc. Figure 2 This is the entity relationship diagram of the underwater acoustic environment database, which includes the environment location entity and its attribute ID, name and location; the environment data entity and its attributes water body conditions, seabed topography, sea surface topography, wind speed, reflection coefficient and sound speed. Among them, the environment location and environment data are one-to-one associated.

[0026] In an optional embodiment, a simulation model Bellhop model is used to simulate the real underwater acoustic channel environment according to the environment file set by the user. In the Bellhop model, the Gaussian beam ray traces the initial beam width and curvature of a given source point, allowing the curvature to increase and decrease as it propagates outward from the sound source. The evolution process of the sound beam is determined by the parameters and Determine the beam width and beam curvature Controlled by the following formula: ; ; Where, is the beam width, is the beam curvature, p is the differential form of p(s), q is the differential form of q(s), is the local sound speed along the ray path, is the arc length along the ray, The speed of sound The second-order derivative in the direction normal to the sound path can be written as: ; Where, is the radial coordinate, is the distance perpendicular to the main sound line, is the vertical coordinate, is the normal vector of the sound ray, which can be written as: ; Where, is the radial component in the normal direction of the sound path, is the vertical component in the normal direction of the sound path.

[0027] Therefore, the beam can be defined as: ; Where, For the beam, is an arbitrary constant, is the distance perpendicular to the main sound line, is the angular frequency of the sound source, is the imaginary unit, The arc length of the sound wave propagating from the sound source to the The cumulative time required for the position.

[0028] In order to make the beam have the form of a sound beam with energy centered on the center and sound line as the center, set and is plural, so The real and imaginary parts of can be expressed by the following formula and the beam width and curvature Get in touch: ; ; Where, beam radius is the amplitude of the beam leaving the main sound line, which is its maximum value The normal distance when is to take the imaginary part of the signal, It is the real part of the signal.

[0029] The weighting of each beam is determined according to the standard point source problem in a homogeneous medium. The formula for the corresponding weighting of the point source and beam is as follows: ; Where, is the weighting coefficient of the sound beam, is the angle between the sound beams, represents the speed of sound in the medium, is the exit angle.

[0030] Adding up the contributions of all beams gives the impulse response at the receiving point: , the formula is as follows: ; Where, is the beam number, For the Sound beam exist The weighting coefficient arriving at the receiver at time, For the The sound beam The propagation delay to the receiver at time , is the unit impulse response, is the delay index in the discrete-time system.

[0031] S2: Obtain the transmit signal of the underwater acoustic communication device, perform down-conversion, convolve it with the impulse response to obtain convolution data, and perform up-conversion to obtain the output signal.

[0032] While defining environmental parameters, the user also inputs the underwater acoustic communication device's interface type, control signal format, transmission signal parameters, and result display parameters into the test system to control the device's transmission signal. Transmission signal parameters include center frequency and bandwidth. When setting the transmission signal parameters for a digital signal, the number of bits transmitted, format, and sampling frequency must be configured. Result display parameters include the signal-to-noise ratio range and a bit error rate line graph.

[0033] Specifically, the underwater acoustic communication device transmits signals based on the underwater acoustic channel and communication interface type. A Bellhop model is run to generate a simulated underwater acoustic channel. The test system then controls the underwater acoustic communication device's transmission signal via a serial port. This application sets the transmission signal to digital. When the underwater acoustic communication device transmits a digital signal, down-conversion is performed; otherwise, signal processing is performed to obtain a digital signal before down-conversion.

[0034] In an optional embodiment, the transmitted signal is an analog signal, and the analog signal of the underwater acoustic communication device under test is read. , first amplify it through a programmable amplifier to obtain the amplified signal, the formula is as follows: ; Where, is the amplified signal, is the gain factor, For time, It is the first letter of the English word "amplifier".

[0035] The amplified signal then passes through a low-pass filter. The impulse response of the low-pass filter is , the filtered signal formula is as follows: ; Where, LPF is the abbreviation of low-pass filter, which means the signal after filtering. is the convolution operation.

[0036] The filtered signal is converted into a digital signal using the following formula: ; Where, is the converted digital signal, It is the first letter of the English letter of Digital Signal. is a discrete time variable, For analog-to-digital conversion.

[0037] In an optional embodiment, the underwater acoustic communication device sends a digital signal, and the digital signal of the underwater acoustic communication device under test is directly read through the external digital interface. .

[0038] The above digital signal is down-converted to obtain the down-converted signal , the formula is as follows: ; Where, is the imaginary unit, is the central angular frequency of the signal, is the sampling period, is a discrete time variable.

[0039] After the digital low-pass filter, its impulse response is , then the signal after low-pass filtering can be expressed as: ; Where, is the signal after low-pass filtering.

[0040] Convolve the impulse response with the filtered signal to obtain the convolution data , the formula is as follows: ; Where, is the signal after being processed by the low-pass filter.

[0041] Adding ambient noise to the convolution data After up-conversion, the output signal is obtained, and the formula is as follows: ; ; ; Where, For environmental noise, is the convolution data, The convolution data after adding noise, if the digital signal output is selected, the output signal output to the underwater acoustic communication device is If the analog signal output is selected, it needs to be filtered, amplified and converted into digital to output the output signal to the underwater acoustic communication device. .

[0042] S3: Send the output signal back to the underwater acoustic communication device, read the demodulation result of the underwater acoustic communication device, and calculate the bit error rate ,according to" Criteria", that is, the number of code elements tested , determine whether the iteration is completed. If so, draw the performance curve; otherwise, continue to control the underwater acoustic communication device to transmit signals for testing.

[0043] After the output signal is input back to the underwater acoustic communication machine, the test system controls the underwater acoustic communication machine through the serial port or network port to send the demodulation result and calculate the bit error rate ,according to" Criteria", that is, the number of code elements tested , determines whether the iteration is complete. If so, plots the performance curve. Otherwise, continues controlling the underwater acoustic communication device to transmit signals for testing. This approach allows for autonomous control of the underwater acoustic communication device, executing automated testing processes, and visually displaying test results in graphical form, improving automation and accuracy.

[0044] See also Figure 3 Another embodiment of the present application provides a hardware-in-the-loop automated performance testing system for underwater acoustic communication devices, comprising a power module, a main processing module connected to the power module, a signal processing module, and a human-computer interaction module. The main processing module includes an FPGA unit and an ARM unit.

[0045] The main processing module sets the environmental parameters according to the input of the human-computer interaction module and the signal processing module, imports the Bellhop model to generate the underwater acoustic channel to obtain the impulse response; obtains the transmission signal of the underwater acoustic communication machine, performs down-conversion and convolves it with the impulse response to obtain the convolution data, performs up-conversion to obtain the output signal; inputs it back to the underwater acoustic communication machine, reads the demodulation result of the underwater acoustic communication machine, and calculates the bit error rate ,according to" Criteria", that is, the number of code elements tested , determine whether the iteration is completed. If so, draw the performance curve; otherwise, continue to control the underwater acoustic communication device to transmit signals for testing.

[0046] The power module provides stable power to the main processing module, signal processing module, and human-computer interaction module. Together, they simulate a real underwater communication channel, enabling automated performance testing of the underwater acoustic communication system. The power module is powered by a 12V lithium battery and uses a highly efficient DC-DC power converter to stabilize the voltage to the required operating voltages. This ensures the stability, energy efficiency, and reliability of the entire test system, meeting the power requirements of high-performance computing and communications. The ±5V voltage uses the TPS5430 wide-input step-down chip, which supports a wide input voltage range of 6V to 36V, delivers a maximum output current of 3A, and achieves a conversion efficiency of up to 95%. The low-voltage components (3.3V and 1.8V) utilize the EC2232 power management chip, which offers high conversion efficiency and built-in overload, overtemperature, and short-circuit protection. The lithium battery management chip uses the TP5100, with built-in protection against input overcurrent, undervoltage, chip overtemperature, short-circuit, battery temperature monitoring, and reverse battery connection. At the same time, the power module has built-in multiple protection mechanisms, including overvoltage, overcurrent, short circuit and overtemperature protection, to ensure that the power module can automatically power off or resume normal operation under abnormal conditions, ensuring the safety and reliability of the system.

[0047] Specifically, the human-computer interaction module includes a host computer and a touchscreen. The touchscreen utilizes a high-resolution, high-sensitivity capacitive touchscreen and supports a graphical user interface (GUI), allowing users to intuitively set test parameters, monitor test progress, and analyze test results in real time. The host computer is connected to the main processing module via the ESP32 module. The ESP32 module includes Wi-Fi and Bluetooth capabilities, enabling remote data transmission and device control. The host computer software is developed using the QT framework, which enables the development of software with a graphical interface. This allows users to intuitively set test parameters, monitor test progress, and analyze results via a computer. Furthermore, the graphical touch interface supports hardware parameter adjustment and is adaptable to underwater acoustic communication devices with different communication interfaces and modulation methods.

[0048] Preferably, the interface type and transmission signal parameters of the underwater acoustic communication device under test are input into the main processing module through the touch screen or host computer interface. If a digital interface is used, the data transmission bit number, format, sampling frequency and other parameters need to be set to complete the data transmission type adaptation.

[0049] Use the touch screen or host computer interface to set the bit error rate threshold and result display type in the main processing module. Result display parameters include plotting signal-to-noise ratio vs. bit error rate curves, distance vs. bit error rate curves, and wind speed vs. bit error rate curves.

[0050] The signal processing module features a flexible hardware circuit design, specifically supporting hardware parameterization. It includes a digital interface, an analog interface, a programmable amplifier, an analog-to-digital converter, a digital-to-analog converter, and a low-pass filter. The digital and analog interfaces are adaptable to underwater acoustic communication devices with different communication interfaces and modulation methods, providing both analog and digital input and output interfaces for the underwater acoustic communication device under test. This allows for connection to analog signals after digital-to-analog conversion, thereby enabling performance testing of the entire hardware system, as well as to digital signals before digital-to-analog conversion. After completing the line connection, the corresponding parameters are entered as needed based on the characteristics of the connected digital interface to adapt to the digital signal transmission requirements.

[0051] Specifically, the underwater acoustic communication device includes a test underwater acoustic transmitter and an underwater acoustic receiver. The signal processing module connects to the test underwater acoustic transmitter via a digital interface or an analog interface to receive the transmission signal from the test underwater acoustic transmitter. The transmission signal is a digital signal or an analog signal. When a digital signal is received, it is directly input into the main processing module through the digital interface. When an analog signal is received, it is input into the programmable amplifier through the analog interface. The programmable amplifier automatically adjusts the gain of the input analog signal to ensure that the signal amplitude is optimized to the optimal input range of the analog-to-digital converter, thereby ensuring high-quality analog signal acquisition. The amplified analog signal is input into the analog-to-digital converter, which converts the filtered analog signal into a digital signal and inputs it into the main processing module.

[0052] The signal processing module receives the processed output signal from the main processing module. This output signal is a digital signal. This digital signal can be directly transmitted back to the underwater acoustic receiver via the digital interface, or it can be converted to an analog signal using a digital-to-analog converter, a low-pass filter, and a programmable amplifier. This signal is then filtered, amplified, and transmitted back to the underwater acoustic receiver. By integrating a low-pass filter and then passing it through a programmable amplifier, functions such as amplitude adjustment are implemented, maximizing the performance of the entire circuit.

[0053] Preferably, analog and digital interfaces are used to connect to the underwater acoustic transmitter under test. The analog interface uses a standard SMA (Sub Miniature version A) connector to connect to the AD / DA (analog-to-digital converter / digital-to-analog converter) of the underwater acoustic communication device under test for analog signal transmission. The digital interface uses a parallel or serial port with adjustable bit count. This interface configuration allows for both analog signal data transmission and digital signal data transmission using a digital interface. Users can select analog or digital mode to read data and complete the line connection based on the circuit connection method of the underwater acoustic communication device under test.

[0054] Specifically, see Figure 4The programmable amplifier, model VCA821, is a DC-coupled, broadband, linear-in-dB, continuously variable voltage-controlled gain amplifier. Powered by a ±5V power supply, the device adjusts the gain control voltage linearly in dB as the control voltage varies from 0V to +2V, achieving gain control from -20dB to 20dB, with a gain deviation of no more than ±0.3dB. Optimizing the output signal amplitudes of different communication devices under test to the optimal input range of the analog-to-digital converter effectively avoids distortion caused by signal overload and prevents increased quantization noise caused by insufficient signal amplitude. This significantly improves the quantization accuracy and signal-to-noise ratio (SNR) of the analog-to-digital converter, thereby enhancing signal acquisition quality.

[0055] This application uses the 3PA9280 analog-to-digital converter. Figure 5 As shown in the figure, the chip features a single chip, single power supply, 8 bits, a maximum conversion speed of 32MSPS, single-ended input, and an on-chip sample-and-hold amplifier and voltage reference. These features enable the analog-to-digital converter to effectively reduce costs while ensuring high integration and accuracy. While maintaining high performance, it also reduces power consumption and makes the signal conversion process more stable. The 3PD9708 digital-to-analog converter is selected, as shown in the figure. Figure 6 As shown, it features a single chip, single power supply, 8-bit operation, and a maximum conversion speed of 125MSPS. The output of the DAC is a pair of differential current signals. To prevent noise interference, an LC low-pass filter is integrated into the signal processing module. A programmable amplifier is used to convert differential currents to single-ended signals and adjust amplitude, maximizing the circuit performance of the entire signal processing module.

[0056] The main processing module consists of an FPGA unit and an ARM unit. The ARM unit is responsible for system logic control and running the Bellhop model; the FPGA unit is responsible for accelerating the Bellhop model and processing underwater acoustic signals in real time, collaboratively driving the entire testing process. Users can customize the simulation environment according to actual needs or call existing environmental data from the database to simulate the real underwater acoustic channel environment and drive the entire testing process.

[0057] Specifically, the main processing module of this application utilizes the domestically produced heterogeneous multi-core platform, the Fudan Micro FMQL20SM. Based on an advanced 28nm process, it integrates a quad-core processor (ARM unit) with a maximum clock speed of 1GHz and 85KB of programmable logic (FPGA unit) within a single chip. The ARM unit runs Linux, and the FPGA unit accelerates signal processing, resulting in low latency and high performance. The Linux system running within the ARM unit of the main processing module supports complex Bellhop models, accurately simulating the propagation characteristics of underwater acoustic channels and providing a realistic and reliable underwater acoustic channel environment for testing.

[0058] In the ARM unit, user-defined or pre-set environment files are selected based on user requirements to generate an underwater acoustic channel and obtain an impulse response. Simultaneously, the ARM unit configures the underwater acoustic transmitter's position, velocity, number of transducers, and transmission angle within the designated underwater acoustic environment, as well as the underwater acoustic receiver's position, velocity, and number of receivers. Once configured, the FPGA unit in the main processing module controls the underwater acoustic communicator via the serial or Ethernet port to transmit a signal. The signal enters the main processing module's FPGA unit for down-conversion. The impulse response from the ARM unit is stored in the FPGA unit and convolved with the processed input signal. Up-conversion is then performed, and the output signal is transmitted back to the underwater acoustic receiver under test via the signal processing module. This process utilizes the FPGA unit for high-speed signal processing, meeting the requirements for real-time underwater acoustic signal processing. During testing, the main processing module remotely controls the external underwater acoustic communicator via the UART (serial) or Ethernet port for signal transmission or reception, supporting automated testing. The serial port is a 3.3V or 5V UART, and the Ethernet port is a standard RJ45 network interface.

[0059] Finally, the ARM unit reads the demodulation results of the underwater acoustic communication device under test through the serial port or network port and calculates the bit error rate ,according to" Criteria", that is, the number of code elements tested , determines whether the iteration is complete. If so, plots the performance curve; otherwise, continues controlling the underwater acoustic communication device to transmit signals for testing. This method can autonomously control the underwater acoustic communication device, execute automated testing processes, and intuitively display test results in graphical form.

[0060] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0061] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A hardware-in-the-loop automated performance testing method for underwater acoustic communication equipment, characterized in that: The following steps are involved: Obtain the environment file, import it into the simulation model to generate the underwater acoustic channel and obtain the impulse response; Acquire a transmission signal of an underwater acoustic communication device, perform down-conversion on the signal, convolve the signal with the impulse response to obtain convolution data, and perform up-conversion on the signal to obtain an output signal; The data is input back to the underwater acoustic communication machine, the demodulation result of the underwater acoustic communication machine is read, the bit error rate is calculated, and it is determined whether the iteration is completed. If so, a performance curve is drawn; otherwise, the underwater acoustic communication machine is continued to be controlled to transmit signals for testing.

2. A hardware-in-the-loop automated performance testing method for underwater acoustic communication equipment as claimed in claim 1, characterized in that: The impulse response convolution formula is as follows: ； Where, is the convolution data, is the impulse response, is the signal processed by the low-pass filter, is a discrete time variable, is the delay index in the discrete-time system.

3. A hardware-in-the-loop automated performance testing method for underwater acoustic communication equipment as claimed in claim 1, characterized in that: The process of obtaining the impulse response includes: calculating a beam according to a beam width and a beam curvature, converting the beam to obtain an acoustic beam, and superimposing all the acoustic beams reaching the target to calculate the impulse response.

4. A hardware-in-the-loop automated performance testing method for underwater acoustic communication equipment as claimed in claim 3, characterized in that: The formula for calculating the beam based on the beam width and beam curvature is as follows: ； ； Where, is the beam width, is the beam curvature, p is the differential form of p(s), q is the differential form of q(s), is the local sound speed along the ray path, is the arc length along the ray, The speed of sound The second-order derivative in the direction normal to the sound path can be written as: ； Where, is the radial coordinate, is the distance perpendicular to the main sound line, is the vertical coordinate, is the normal vector of the sound ray, which can be written as: ； Where, is the radial component in the normal direction of the sound path, is the vertical component in the normal direction of the sound path; The beamformulation formula is: ； Where, For the beam, is an arbitrary constant, is the distance perpendicular to the main sound line, is the angular frequency of the sound source, is the imaginary unit, The arc length of the sound wave propagating from the sound source to the The cumulative time required for the position.

5. A hardware-in-the-loop automated performance testing method for underwater acoustic communication equipment as claimed in claim 3, characterized in that: The impulse response formula is as follows: ； Where, is the beam number, For the The sound beam The weighting coefficient of time, For the The sound beam The propagation delay of time, is the unit impulse response, is the delay index in the discrete-time system.

6. A hardware-in-the-loop automated performance testing method for underwater acoustic communication equipment as claimed in claim 1, characterized in that: Before obtaining the transmission signal of the underwater acoustic communication device, it is necessary to input the interface type, control signal format, transmission signal parameters and result display parameters of the underwater acoustic communication device.

7. A hardware-in-the-loop automated performance testing method for underwater acoustic communication equipment as claimed in claim 6, characterized in that: Before down-conversion, the transmission signal needs to be judged whether it is a digital signal. If it is a digital signal, it is directly down-converted; otherwise, it needs to be amplified, filtered and converted into a digital signal before down-conversion.

8. A hardware-in-the-loop automated performance test system for underwater acoustic communication equipment, applied to the hardware-in-the-loop automated performance test method for underwater acoustic communication equipment described in any one of claims 1 to 7, comprising a power supply module, characterized in that: It also includes a main processing module, a signal processing module and a human-computer interaction module connected to the power module; The main processing module obtains the environment file based on the input of the human-computer interaction module and the signal processing module, imports the simulation model to generate the underwater acoustic channel to obtain the impulse response; obtains the transmission signal of the underwater acoustic communication machine, performs down-conversion and convolves it with the impulse response to obtain convolution data, and performs up-conversion to obtain the output signal; inputs it back to the underwater acoustic communication machine, reads the demodulation result of the underwater acoustic communication machine, calculates the bit error rate, and determines whether the iteration is completed. If so, draws the performance curve; otherwise, continues to control the underwater acoustic communication machine to transmit the signal for testing.

9. A hardware-in-the-loop automated performance testing system for underwater acoustic communication equipment as claimed in claim 8, characterized in that: The input of the human-computer interaction module includes the interface type, control signal format, transmission signal parameters and result display parameters of the underwater acoustic communication device; The main processing module includes an FPGA unit and an ARM unit, and the signal processing module includes a programmable amplifier, an analog-to-digital converter, a digital-to-analog converter and a low-pass filter.

10. A hardware-in-the-loop automated performance testing system for underwater acoustic communication equipment as claimed in claim 9, characterized in that: The control signal format is used to control the underwater acoustic communication device to send the demodulation result to the human-computer interaction module through a serial port or a network port for the judgment.

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