An underwater acoustic signal transmitting device with broadband and residual vibration attenuation

Abstract

The application relates to a water acoustic signal transmitting device with wide frequency and residual vibration attenuation, which comprises a transmitting circuit and sequentially connected master control chip, excitation signal generating module, wide frequency impedance matching network, transformer and water acoustic transducer; the transmitting circuit comprises a power supply module, an energy storage module, a controllable high-voltage module and a residual vibration attenuation module; the residual vibration attenuation module is used for measuring the current signal in the water acoustic transducer and transformer loop, and when the current is greater than a set threshold, the residual energy in the transformer and the water acoustic transducer is discharged. Compared with the prior art, the application has good characteristics of large power, wide frequency band and low residual vibration, can effectively enhance the signal gain of the water acoustic transducer, reduce residual vibration interference, increase the working frequency range, and further enhance the signal radiation performance of the sonar detection equipment and the application environment multi-adaptability.

Description

Technical Field

[0001] This invention relates to the field of underwater acoustic detection technology, and in particular to a marine acoustic signal transmitting device with wide bandwidth and residual vibration attenuation function. Background Technology

[0002] As a major maritime power, my country's advancement in marine affairs necessitates enhanced capabilities for marine resource development. Sonar is a crucial technological tool for marine exploration and engineering, and its performance directly determines the quality of underwater acoustic detection. To achieve longer detection ranges and better target identification capabilities, sonar transmitters require wideband excitation capabilities, operating at low frequencies for long-distance communication and at high frequencies for identifying close-range targets. However, after a single excitation, the transmitter transducer experiences residual vibration, which increases the sonar's blind zone due to interference. Therefore, to further improve the performance of my country's sonar detection systems, it is imperative to address the issues of wideband performance and low residual vibration in marine underwater acoustic transmitters.

[0003] Because the admittance of underwater acoustic transducers fluctuates dramatically with frequency, achieving impedance matching over a wide frequency range is extremely difficult. A large amount of reactive power exists within the transducer's admittance band, which can easily lead to impedance mismatch between the transducer load and the transmitting circuit in the transmitting module. This results in low active power output from the transducer, severely impacting signal detection range. Simultaneously, when the excitation signal ends, residual energy remains in the transformer coil and the transducer's static capacitor, causing residual vibration interference that increases the sonar detection blind zone. Since this signal is closely linked to the excitation signal, improper attenuation control can distort the transmitted signal, affecting the quality of underwater acoustic detection.

[0004] Current underwater acoustic signal transmission modules suffer from poor bandwidth performance. Impedance matching design often employs the real-frequency data method, which fails to converge when the bandwidth is large and the number of components is high. Furthermore, this method struggles to perform radial analysis of the average impedance within the bandwidth, leading to unbalanced bandwidth responses when component values ​​are inappropriate. In addition, effective residual vibration attenuation is lacking; conventional bleeder resistors cannot effectively distinguish between the excitation signal and the residual vibration signal, resulting in distortion of the original signal.

[0005] Although the Chinese patent applications CN200410089145.X and CN202210414560.6 use multiple frequency band transducers or reactance matching circuits for switching, which can indirectly achieve the purpose of broadband impedance matching, the control circuit is complex and multiple transducers and matching circuits will occupy a lot of instrument space, making it unusable for some small sonar detection equipment.

[0006] Regarding the attenuation of transducer residual vibration, patent application CN202011172364.X addresses ultrasonic transducers from the perspective of the excitation function. This method involves complex calculations and does not attenuate the residual vibration signal at its source. Instead, it utilizes a suppression signal generated after the residual vibration signal ends to cause the transducer to vibrate in the opposite direction, thus canceling it out. This is an indirect method suitable for low-power ultrasonic transducers. For high-power marine acoustic detection equipment, this residual vibration attenuation method suffers from high energy consumption and is ineffective for large-sized underwater acoustic transducers with significant vibration inertia. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a hydroacoustic signal transmitting device with wide bandwidth and residual vibration attenuation.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] A hydroacoustic signal transmitting device with wideband bandwidth and residual vibration attenuation includes a transmitting circuit and a main control chip, an excitation signal generation module, a wideband impedance matching network, a transformer, and a hydroacoustic transducer connected in sequence; the transmitting circuit includes a power supply module, an energy storage module, a controllable high voltage module, and a residual vibration attenuation module.

[0010] The residual vibration attenuation module is used to measure the current signal in the underwater acoustic transducer and transformer circuit. When the current is greater than the set threshold, it releases the residual energy in the transformer and underwater acoustic transducer.

[0011] Furthermore, the calculation steps for the impedance matching network element parameters are as follows:

[0012] The equivalent circuit parameters of the underwater acoustic transducer were obtained using an impedance analyzer.

[0013] By combining the equivalent circuit parameters of the underwater acoustic transducer with the broadband impedance matching network, the power mathematical model of the impedance matching network is obtained.

[0014] Calculate the power mathematical model of the impedance matching network to obtain the parameter values ​​of the impedance matching network components.

[0015] Furthermore, the power mathematical model of the impedance matching network is solved using an adaptive Gauss-Newton iterative algorithm to obtain the component parameters in the impedance matching network. The specific steps are as follows:

[0016] Based on the established power mathematical model, the required bandwidth and target power gain are the main calculation boundary conditions, and the port reflection coefficient is set as a triple weighting coefficient to form auxiliary boundary conditions.

[0017] The average impedance within the target frequency band is tracked using an adaptive Gauss-Newton iterative algorithm. If the calculation results do not converge, the process returns to the weighting coefficient selection to change the port reflection coefficient.

[0018] If the calculation converges, the power gain deviation is further checked to see if it is less than the set threshold. If it is not satisfied, the average impedance tracking continues until the final output impedance matching network component parameter value is reached.

[0019] Furthermore, the impedance matching network is a Π-type impedance matching network structure, including two capacitors. and and three inductor components , and ;

[0020] The One end is connected to the positive terminal of the excitation signal generation module, and the other end is simultaneously connected to... Connected and ; The other end is connected to CB; Connect one end The other end is connected at the same time and , The other end is connected to CA; Connect one end The other end is connected to a transformer.

[0021] Furthermore, the power mathematical model of the broadband impedance matching network is as follows:

[0022]

[0023] in, j It is a complex number. w Angular frequency, To match the network impedance input function, For the output function of the impedance matching network, Let the transducer load impedance function be . Where n is the static capacitive reactance and n is the transformer turns ratio. For the primary inductance of the transformer, This is the value of the transformer's secondary inductance. Input voltage to the port. Input current to the port. and These are the capacitance values ​​of the corresponding capacitors. , and These are the inductance values ​​of the corresponding inductors.

[0024] Furthermore, the residual vibration attenuation module includes:

[0025] The current acquisition chip is used to measure the current signal in the underwater acoustic transducer and transformer circuit. When the current exceeds the set threshold, it triggers the residual vibration attenuation control.

[0026] Residual energy release is used to release residual energy in transformers and transducers from the ground wire.

[0027] Furthermore, the residual energy release includes a controllable switching device and one or more parallel reverse diodes.

[0028] Furthermore, the excitation signal generation module includes: a power amplifier chip, an isolation transformer, and an H-bridge.

[0029] Furthermore, the underwater acoustic transducer is a composite rod piezoelectric transducer.

[0030] Furthermore, the underwater acoustic signal transmitting device also includes a host computer control system, which includes a communication module connected to the main control chip and a host computer that interacts with the communication module for control commands and status detection.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1) The novel wideband and residual vibration attenuation transmitting circuit module for marine acoustic transducers designed in this invention combines the advantages of high power, wide bandwidth and low residual vibration, which can effectively enhance the signal gain of the underwater acoustic transducer, reduce residual vibration interference, increase the operating frequency range, and further enhance the signal radiation performance and application environment adaptability of sonar detection equipment.

[0033] 2) The broadband network element calculation method of this invention is more intelligent, capable of adaptively tracking the average impedance of the frequency band. When the calculation fails to converge, it can switch boundary conditions and dynamically apply the weights of three port reflection coefficients, resulting in a flatter broadband frequency response. Regarding residual vibration attenuation technology, this invention starts from the mechanism of residual vibration generation, and the attenuation method is simple and highly feasible in engineering, suitable for underwater acoustic transducers with high power and vibration inertia, meeting the low power consumption requirements of marine sonar equipment. Simultaneously, this invention implements both broadband and residual vibration attenuation functions on a single transmitting module, greatly simplifying the space required for sonar detection equipment. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the underwater acoustic signal transmitting device with wide bandwidth and residual vibration attenuation according to the present invention.

[0035] Figure 2 This is a schematic diagram of the Π-type matching network connection provided by the present invention;

[0036] Figure 3The flowchart of the broadband impedance matching calculation method provided by the present invention is shown below;

[0037] Figure 4 The flowchart of the signal control process of the controlled residual vibration attenuation module provided by the present invention;

[0038] Figure 5 This is a schematic diagram of the residual vibration attenuation circuit structure provided by the present invention;

[0039] Figure 6 A schematic diagram of the current detection circuit structure provided by this invention;

[0040] Figure 7 This is a schematic diagram of the circuit structure of the energy storage and release part provided by the present invention;

[0041] Figure 8 The present invention provides an assembly diagram of the transmitting circuit;

[0042] Figure 9 This is a schematic diagram of the residual vibration attenuation effect provided by the present invention;

[0043] Figure 10 The active power broadband response diagram provided for this invention. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0045] Example 1

[0046] This invention proposes a marine acoustic signal transmitting device with wideband and residual vibration attenuation functions, such as... Figure 1As shown, the module includes a host computer control system, a transmitting circuit (power supply module, energy storage module, controllable high-voltage module), a wideband impedance matching network, a residual vibration attenuation module, and an underwater acoustic transducer; the residual vibration attenuation module is located on the transmitting circuit. First, the power supply module converts 220V to 15V to power the entire system. The low-voltage power supply module, after passing through a voltage conversion chip, supplies 1.2V and 3.3V to the low-voltage modules, mainly the FPGA and RS485 communication module, and then supplies 15V to the high-voltage power supply of the transmitting circuit and the controlled residual vibration attenuation module. The main control chip uses an FPGA to generate control signals with continuously adjustable cycle count, frequency, and output voltage from 2-20 kHz. The host computer issues transmission command parameters. A total of four low-voltage control signals, after passing through a power amplifier chip MCP1407 and an isolation transformer, drive an H-bridge to generate a bipolar high-voltage pulse excitation signal. This signal passes through the wideband impedance matching network designed in this invention, and is then boosted by a pulse transformer to excite the underwater acoustic transducer to radiate acoustic signals. The controlled residual vibration attenuation module first uses an INA282 current acquisition chip to measure the current signal in the transducer and transformer circuits. When the current exceeds 0.35A, residual vibration attenuation control is triggered. The FPGA sends a drive signal to turn on the MOSFET, allowing the residual energy in the transformer and transducer to be discharged through a wideband impedance matching network to the ground. The parasitic resistance in the wideband impedance matching network further attenuates the residual stored energy. This is because the transducer is a piezoelectric device. When the circuit is under high-voltage excitation, its circuit current is very small, not exceeding 0.3A. However, when the excitation ends, the energy in the transformer coil and the static capacitor of the transducer is a short-circuit current, characterized by a current intensity significantly higher than the excitation signal current. Therefore, once the current sensor detects that the current value exceeds the preset threshold after the excitation ends, it sends a flag signal to the FPGA, indicating that residual vibration attenuation can be activated. This invention is based on the deep mechanism of residual vibration generation. It uses a current acquisition chip to detect the secondary current of the transformer. However, after the excitation signal ends, it uses the characteristics of the transformer and static capacitor to discharge large current and identify the attenuation time of the residual vibration signal. It uses the switching characteristics of the MOSFET and adds a protection circuit of a reverse diode to release the residual energy through the ground wire. The residual vibration attenuation method of this invention is more intuitive and has higher applicability in practical engineering.

[0047] The innovations of this invention include: a wideband impedance matching network design method based on adaptive Gauss-Newton; and a controlled residual oscillation attenuation circuit module design based on threshold current monitoring.

[0048] The broadband impedance matching design method of this invention employs a Π-type impedance matching network composed of four inductor-capacitor elements. First, the equivalent circuit parameters of the underwater acoustic transducer are obtained using an impedance analyzer. Then, these parameters are combined with the broadband impedance matching network to calculate its power mathematical model. Figure 2The diagram shows the Π-type impedance matching network structure used in this invention, consisting of two capacitors and three inductors, namely CA, CB, LA, LB, and LC. One end of LA is connected to the positive terminal of the signal source in the preceding circuit, and the other end is connected to CA. Simultaneously, after connecting CA and LA, it is connected to one end of LB. The other end of CA is connected to CB. One end of LB is connected to one end of LA, and simultaneously connected to CB and LC. The other end of CB is connected to CA, and the other end of LC is connected to transformer port 1. The following power mathematical model can be obtained:

[0049]

[0050] Where j is a complex number, w is the angular frequency, Y1 is the impedance input function of the matching network, Y2 is the output function of the impedance matching network, X2 is the transducer load impedance function, X1 is the static capacitive reactance, n is the transformer turns ratio, Lm is the primary inductance of the transformer, Ls is the secondary inductance of the transformer, Vi is the port input voltage, and i1 is the port input current.

[0051] The matching network port 1 is connected to the positive terminal of the signal source of the previous stage circuit (i.e., the... Figure 5 The upper arm (S-pole) of the H-bridge is connected to the negative terminal of the signal source (i.e., the...). Figure 5 The ground wire in the transformer is connected to the transformer's negative terminal 1 via a wideband impedance matching network port 3. The wideband impedance matching network port 4 is connected to the transformer's negative terminal 4. Transformer ports 5 and 8 are connected to the positive and negative terminals of the transducer, respectively. The transducer used is a composite rod piezoelectric transducer, with PZT-4 or PZT5A piezoelectric material. The transducer's radiating head is made of hard aluminum. Five highly polarized annular transducers are stacked alternately in parallel. The step-up transformer used is a toroidal transformer with a ferrite core and a turns ratio of 1:n, where n ranges from 5 to 16.

[0052] Based on this computational model, the adaptive Gauss-Newton iterative algorithm is applied to solve for the component parameters in the impedance matching network. The specific computational flowchart is shown below. Figure 3 As shown, the main steps are as follows: Based on the established power mathematical model, the required bandwidth and target power gain are used as the main calculation boundary conditions, and the port reflection coefficient is set with triple weighting coefficients (0.2 dB, 0.4 dB, 0.6 dB) to form auxiliary boundary conditions. The adaptive Gauss-Newton iterative algorithm is used to track the average impedance within the target bandwidth. If the calculation result does not converge, the process returns to the weighting coefficient selection to change the port reflection coefficient; if the calculation converges, the power gain deviation is further judged to be less than 10%. If it does not meet the requirement, the average impedance tracking continues until the final output of the matching network element parameter values.

[0053] Compared with existing technologies, the broadband network element calculation method of this invention is more intelligent, capable of adaptively tracking the average impedance of the frequency band. When the calculation fails to converge, it can switch boundary conditions and dynamically apply the weights of three port reflection coefficients, resulting in a flatter broadband frequency response. Regarding residual vibration attenuation technology, this invention starts from the mechanism of residual vibration generation, and the attenuation method is simple and highly feasible in engineering, suitable for underwater acoustic transducers with high power and vibration inertia, meeting the low power consumption requirements of marine sonar equipment. Simultaneously, this invention implements both broadband and residual vibration attenuation functions on a single transmitting module, greatly simplifying the space required for sonar detection equipment.

[0054] Controlled residual vibration attenuation module design, such as Figure 4-7 As shown, this module consists of two current monitoring parts. An IN282 current acquisition chip monitors the primary current of the transformer and transmits the current value to the FPGA in real time. When the current exceeds 0.35A, a drive signal is sent to MOSFET Q7 to turn it on; other current values ​​trigger a turn-off signal. The gate (G) of MOSFET Q7 is connected to the FPGA signal output I / O, the drain (D) is connected to the primary coil of the transformer, and the source (S) is connected to the X50UFG reverse diode. Upon receiving the turn-on command, the remaining energy in the transformer and the transducer's static capacitor is transferred from the primary coil of the transformer through electromagnetic induction. Since the H-bridge circuit is already in the off state after the excitation signal ends, the current direction is reversed. After MOSFET Q7 turns on, the current is attenuated by the two parallel reverse diodes X50UFG to prevent backflow due to short circuits in other components, and finally released to ground. Once the residual energy is discharged from the designed circuit, the residual oscillation signal is significantly attenuated.

[0055] The novel wideband and residual vibration attenuation transmitting circuit module for marine acoustic transducers designed in this invention combines the advantages of high power, wide bandwidth, and low residual vibration. It can effectively enhance the signal gain of the underwater acoustic transducer, reduce residual vibration interference, and increase the operating frequency range, thereby further enhancing the signal radiation performance and application environment adaptability of sonar detection equipment.

[0056] Example 2

[0057] Specific embodiments: The launching device of the present invention is as follows Figure 1 and Figure 8As shown, the main control chip is an FPGA, which communicates with the host computer via an RS485 serial port. When the host computer sends commands such as the transmission signal frequency (range 1 kHz-20 kHz), number of cycles (range 1-5), time interval (500 ms-3 S), and input high voltage (range 0-400V), the FPGA generates four +3.3V low-voltage control signals. After passing through a power amplifier circuit composed of MCP1407, it forms a +15V MOS transistor drive signal, which alternately conducts the H-bridge to generate a 400V bipolar high-voltage excitation signal. This signal passes through a wideband impedance matching network. The network element parameters are obtained using the innovative adaptive Gauss-Newton algorithm of this invention (the innovation lies in the boundary condition setting and average impedance tracking). For the impedance data of the underwater acoustic transducer used in this invention, the network element parameters are as follows: CA: 6.45uF, CB: 4.32uF, LA: 312.43uH, LB: 1.23mH, LC: 2.88mH. After passing through the Π-type network, the signal drives the transducer via a 1:8 step-up transformer. The IN282 continuously monitors the primary current of the transformer and sends the data to the FPGA. When the excitation signal ends, the H-bridge closes. If the primary current of the transformer exceeds 0.35V, the FPGA sends a flag signal to turn on the Q7 MOS transistor. The Q7 MOS transistor turns on, forming a loop to ground, allowing the residual energy in the transformer coil and the transducer's static capacitor to flow into the ground line through two parallel reverse diodes. This effectively reduces residual energy and minimizes residual oscillations in the transducer's output. Figure 9 The diagram shows the excitation signal generated by a conventional transmitting module and the signal generated by the transmitting module of this invention exciting the same transducer. It can be seen that the transmitting module of this invention not only effectively increases the transmitting voltage by 2 times (from 500V to 1000V), but also attenuates the residual oscillation signal by 4dB, and accurately releases residual energy after the excitation signal is completed. Furthermore, the wideband impedance matching network of this invention has excellent filtering characteristics, capable of removing spike pulses from the square wave signal output by the H-bridge, resulting in a smoother excitation waveform and a more stable transducer vibration mode. Figure 10 As shown in the active power test, the transmitting module of the present invention can effectively broaden the transmitting bandwidth of the underwater acoustic transducer and increase the active power output by 3 times.

[0058] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A hydroacoustic signal transmitting device with wide bandwidth and residual vibration attenuation, characterized in that, It includes a transmitting circuit and a main control chip, an excitation signal generation module, a wideband impedance matching network, a transformer, and an underwater acoustic transducer connected in sequence; the transmitting circuit includes a power supply module, an energy storage module, a controllable high voltage module, and a residual vibration attenuation module; The residual vibration attenuation module is used to measure the current signal in the underwater acoustic transducer and transformer circuit. When the current is greater than the set threshold, it releases the residual energy in the transformer and underwater acoustic transducer. The calculation steps for the parameters of the broadband impedance matching network elements are as follows: The equivalent circuit parameters of the underwater acoustic transducer were obtained using an impedance analyzer. By combining the equivalent circuit parameters of the underwater acoustic transducer with the broadband impedance matching network, the power mathematical model of the broadband impedance matching network is obtained. The power mathematical model of the broadband impedance matching network is calculated to obtain the component parameter values. The power mathematical model of the broadband impedance matching network is solved using an adaptive Gauss-Newton iterative algorithm. The specific steps are as follows: Based on the established power mathematical model, the required bandwidth and target power gain are the main calculation boundary conditions, and the port reflection coefficient is set as a triple weighting coefficient to form auxiliary boundary conditions. The average impedance within the target frequency band is tracked using an adaptive Gauss-Newton iterative algorithm. If the calculation results do not converge, the process returns to the weighting coefficient selection to change the port reflection coefficient. If the calculation converges, the power gain deviation is further checked to see if it is less than the set threshold. If it is not satisfied, the average impedance tracking continues until the final output of the wideband impedance matching network component parameter values.

2. The underwater acoustic signal transmitting device with wide bandwidth and residual vibration attenuation according to claim 1, characterized in that, The broadband impedance matching network is a Π-type impedance matching network structure, including two capacitors. and and three inductor components , and ; The One end is connected to the positive terminal of the excitation signal generation module, and the other end is simultaneously connected to... Connected and ; The other end is connected to CB; Connect one end The other end is connected at the same time and , The other end is connected to CA; Connect one end The other end is connected to a transformer.

3. The underwater acoustic signal transmitting device with wide bandwidth and residual vibration attenuation according to claim 2, characterized in that, The power mathematical model of the broadband impedance matching network is as follows: in, j It is a complex number. w Angular frequency, For the impedance input function of the broadband matching network, For the output function of the broadband impedance matching network, Let the transducer load impedance function be . Where n is the static capacitive reactance and n is the transformer turns ratio. For the primary inductance of the transformer, This is the value of the transformer's secondary inductance. Input voltage to the port. Input current to the port. and These are the capacitance values ​​of the corresponding capacitors. , and These are the inductance values ​​of the corresponding inductors.

4. The underwater acoustic signal transmitting device with wide bandwidth and residual vibration attenuation according to claim 1, characterized in that, The residual vibration attenuation module includes: The current acquisition chip is used to measure the current signal in the underwater acoustic transducer and transformer circuit. When the current exceeds the set threshold, it triggers the residual vibration attenuation control. Residual energy release is used to release residual energy in transformers and transducers from the ground wire.

5. The underwater acoustic signal transmitting device with wide bandwidth and residual vibration attenuation according to claim 4, characterized in that, The residual energy release includes a controllable switching device and one or more parallel reverse diodes.

6. The underwater acoustic signal transmitting device with wide bandwidth and residual vibration attenuation according to claim 1, characterized in that, The excitation signal generation module includes: a power amplifier chip, an isolation transformer, and an H-bridge.

7. The underwater acoustic signal transmitting device with wide bandwidth and residual vibration attenuation according to claim 1, characterized in that, The underwater acoustic transducer is a composite rod piezoelectric transducer.

8. A hydroacoustic signal transmitting device with wide bandwidth and residual vibration attenuation according to claim 1, characterized in that, The underwater acoustic signal transmitting device also includes a host computer control system, which includes a communication module connected to the main control chip and a host computer that interacts with the communication module for control commands and status detection.

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