An in-situ measurement system and method for low frequency acoustic properties in marine sediments

Abstract

The present application relates to a kind of in-situ measurement system and method of low frequency acoustic characteristics in seabed sediment, belong to seabed sediment measuring equipment technical field, the in-situ measurement system of low frequency acoustic characteristics in seabed sediment includes main frame, probe rod, penetration mechanism, swing arm mechanism and control cabin;Wherein, probe rod and penetration mechanism detachably connect in the stand of main frame, when measuring work, according to the characteristics of seabed sediment, select installation sampling probe rod or geological probe rod;When measuring work selects sampling probe rod, install vibration penetration mechanism;When measuring work selects geological probe rod, install water jet drilling mechanism.The in-situ measurement system and method of low frequency acoustic characteristics in seabed sediment can select suitable probe rod and penetration mechanism according to different types of seabed sediment, have strong adaptability, and can improve the penetration efficiency of measuring system, to improve overall measurement efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of seabed sediment measurement equipment, and particularly relates to an in-situ measurement system and method for the low-frequency acoustic characteristics of seabed sediments. Background Technology

[0002] The measurement and study of the acoustic properties of seabed sediments have significant application value in military, marine science, and production fields such as ocean acoustic field prediction, underwater target detection, underwater communication and navigation, seabed topographic mapping, and seabed resource exploration. The acoustic properties of seabed sediments mainly refer to two acoustic parameters: the propagation speed of sound waves of different frequencies in the sediment (sound velocity) and the absorption of sound wave energy by the sediment (sound attenuation coefficient). In actual measurements, the composition of sediments varies depending on the location on the seabed. For example, sandy silt contains less sand grains and is mainly composed of silt, resulting in smaller particles, higher density, and lower hardness. Conversely, silty sand contains more sand grains and is mainly composed of sand, resulting in larger particles, higher hardness, and a looser texture. These different sediment characteristics lead to varying penetration efficiencies in the measurement system.

[0003] In the prior art, Chinese invention patent application CN111103622A discloses an in-situ measurement system and method for the low-frequency acoustic properties of seabed sediments. This system utilizes a horizontal probe to install a low-frequency transmitting transducer and a vertical probe to install a broadband receiving transducer, thus achieving the measurement of the acoustic properties of low-frequency sound waves. However, this patent uses a same-center penetration method to penetrate sediments with different properties, which affects the penetration efficiency of the measurement system, thereby impacting the measurement efficiency.

[0004] Therefore, how to provide a measurement system that can change the penetration mode according to the characteristics of sediments is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an in-situ measurement system and method for low-frequency acoustic properties of seabed sediments. With a detachable probe and penetration mechanism, the appropriate probe and penetration mechanism can be selected according to different types of seabed sediments, exhibiting strong adaptability.

[0006] This invention provides an in-situ measurement system for low-frequency acoustic properties of seabed sediments, comprising:

[0007] The main frame includes an upper end face, a lower end face, and a support frame. The two ends of the support frame are respectively enclosed around the periphery of the upper end face and the periphery of the lower end face. The upper end face is used to connect with the hull. A column is provided in the middle of the main frame, and the column is vertically connected to the upper end face and the lower end face.

[0008] The probe rod is detachably connected to the column. The probe rod is slidably connected to the column and can be vertically raised and lowered relative to the column. It is used to penetrate seabed sediments. A receiving transducer capable of receiving low- and medium-frequency sound waves is installed at the end of the probe rod closest to the seabed sediments. The probe rod includes a sampling probe rod or a geological probe rod. When conducting measurement work, the sampling probe rod or the geological probe rod is selected and installed according to the characteristics of the seabed sediments.

[0009] The penetration mechanism is detachably connected to and slidably connected to the column, and is used to provide power for the probe to penetrate the seabed sediment; the penetration mechanism includes a vibratory penetration mechanism or a water jet drilling mechanism. When a sampling probe is selected for the measurement work, a vibratory penetration mechanism is installed; when a geological probe is selected for the measurement work, a water jet drilling mechanism is installed.

[0010] The swing arm mechanism is fixedly connected to the main frame. The swing arm mechanism is equipped with a rotatable first link. The first link is equipped with a transmitting transducer that can emit low-to-medium frequency sound waves. When performing measurement work, the first link rotates to a horizontal direction perpendicular to the probe.

[0011] The control cabin is fixedly connected to the main frame and is communicatively connected to the receiving transducer and the transmitting transducer, respectively, for controlling the receiving transducer and the transmitting transducer.

[0012] This technical solution allows for the selection of appropriate probes and penetration mechanisms based on different types of seabed sediments, demonstrating strong adaptability.

[0013] In some embodiments, the sampling probe is hollow inside, and a sampling port is provided at the end of the sampling probe. When the sampling probe penetrates the seabed sediment, some of the seabed sediment enters the interior of the sampling probe through the sampling port to complete the sampling. A vibration penetration mechanism is installed at the end of the sampling probe away from the sampling drill bit. The vibration penetration mechanism includes at least one pair of vibration motors, which are used to drive the sampling probe to move vertically downward.

[0014] In some embodiments, the end of the geological probe is provided with a geological drill bit, the outer periphery of the geological probe is provided with a sleeve, and a flushing gap is provided between the geological probe and the sleeve; a water jet drilling mechanism is installed at the end of the geological probe away from the geological drill bit, the water jet drilling mechanism includes a rotary motor and a high-pressure water pump, the outlet of the high-pressure water pump is connected to the flushing gap, the rotary motor drives the geological probe to move vertically downward, and the high-pressure water pump is used to inject water into the flushing gap to clean the geological probe.

[0015] In some embodiments, the swing arm mechanism further includes a rotating component and a slide rail. The slide rail is fixedly connected to the rotating component and rotates with the rotating component. The first link is slidably connected to the slide rail vertically and rotates with the rotating component and the slide rail. When the first link rotates to a horizontal direction perpendicular to the probe, the first link slides vertically along the slide rail to adjust the relative height of the transmitting transducer and the seabed sediment.

[0016] In some embodiments, the swing arm mechanism further includes a second link connected to the end of the first link away from the slide rail; a pressure sensor is mounted on the second link, and when the first link rotates to a horizontal direction perpendicular to the probe, the sensing surface of the pressure sensor is at the same height as the lowest point of the transmitting transducer. The pressure sensor is used to assist in detecting the pressure on the transmitting transducer in order to determine whether the relative height between the transmitting transducer and the seabed sediment is appropriate.

[0017] In some embodiments, the in-situ measurement system for low-frequency acoustic properties of seabed sediments further includes a traction mechanism. The traction mechanism is fixedly installed within the main frame and includes a traction rope, one end of which is connected to the probe rod for pulling or lifting the probe rod. This technical solution makes the operation of the probe rod more convenient, easily achieving the lifting of the probe rod.

[0018] In some embodiments, the traction mechanism further includes a winch, which is fixedly connected to the main frame. The other end of the traction rope is wound around the winch, which is used to raise and lower the traction rope. This technical solution utilizes a winch to make the raising and lowering of the traction rope more efficient, facilitating the operation and management of the measurement system.

[0019] In addition, the present invention also provides an in-situ measurement method for low-frequency acoustic properties of seabed sediments, applied to the aforementioned in-situ measurement system for low-frequency acoustic properties of seabed sediments, comprising the following steps:

[0020] S1. Based on the characteristics of seabed sediments in the exploration area, select the appropriate probe and penetration mechanism, and install the in-situ measurement system.

[0021] S2, lower the in-situ measurement system to the seabed sediment and use the swing arm mechanism to rotate the first link to the horizontal direction;

[0022] S3, using the penetration mechanism to drive the probe to penetrate the seabed sediment to a preset depth;

[0023] S4, the control cabin controls the transmitting transducer to emit acoustic signals with preset parameters, and controls the receiving transducer to receive acoustic signals, while recording the emitted and received acoustic signals respectively.

[0024] S5. Repeat steps S3-S4 to obtain the acoustic characteristics of acoustic signals with different parameters in seabed sediments at different depths.

[0025] S6, lift the in-situ measurement system upwards to a certain distance away from the seabed;

[0026] S7. Repeat step S4 to obtain the acoustic characteristics of sound wave signals with different parameters in water at different depths.

[0027] This technical solution first measures the acoustic properties of seabed sediments, then uses an in-situ measurement system to measure the acoustic properties of the water near the sediments. This provides more sufficient data support for correcting and interpreting the acoustic properties of seabed sediments, improving the accuracy and reliability of the measurements.

[0028] In some embodiments, step S2 further includes sliding the first link vertically along the slide rail to adjust the relative height of the transmitting transducer to the seabed sediment.

[0029] In some embodiments, step S6 further includes using a traction rope to pull the probe upwards and lift it from the seabed sediment; in step S7, before repeating step S4, the probe is driven down to a preset depth using a penetration mechanism.

[0030] Based on the above scheme, the in-situ measurement system for low-frequency acoustic properties of seabed sediments in this embodiment of the invention can select appropriate probes and penetration mechanisms according to different types of seabed sediments, has strong adaptability, can perform effective measurements in various environments, and can improve the penetration efficiency of the measurement system, thereby improving the overall measurement efficiency. The in-situ measurement method for low-frequency acoustic properties of seabed sediments first measures the acoustic properties of the seabed sediments, and then raises the in-situ measurement system to measure the acoustic properties of the water body near the seabed sediments. This can provide more sufficient data support for correcting and interpreting the acoustic property data of seabed sediments, and improve the accuracy and reliability of the measurement. Attached Figure Description

[0031] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0032] Figure 1 This is a schematic diagram of the working state structure of the in-situ measurement system for low-frequency acoustic properties of seabed sediments in an embodiment of the present invention.

[0033] Figure 2 This is a schematic diagram of the in-situ measurement system for low-frequency acoustic properties of seabed sediments in an embodiment of the present invention.

[0034] Figure 3 This is a structural disassembly diagram of the in-situ measurement system for low-frequency acoustic properties of seabed sediments in an embodiment of the present invention;

[0035] Figure 4 This is a structural diagram of the main framework;

[0036] Figure 5 This is a schematic diagram of the traction mechanism.

[0037] Figure 6This is a schematic diagram of the swing arm mechanism;

[0038] Figure 7 A schematic diagram of the water jet drilling mechanism and the geological probe;

[0039] Figure 8 This is a schematic diagram of the vibration penetration mechanism and the sampling probe.

[0040] In the picture:

[0041] 1. Main frame; 2. Probe rod; 3. Penetration mechanism; 4. Traction mechanism; 5. Launch control cabin; 6. Launch transducer; 7. Receiver control cabin; 8. Receiver transducer; 9. Swing arm mechanism; 10. Camera; 11. Load-bearing head; 12. Power supply;

[0042] 101. Column; 102. Limiting plate;

[0043] 211. Sampling drill bit; 212. Sampling tube; 213. Outer tube; 221. Geological drill bit; 222. Sleeve;

[0044] 301. Sliding connector; 311. Rotary motor; 312. High-pressure water pump; 321. Vibrating motor; 322. Eccentric wheel;

[0045] 401. Winch; 402. Traction rope; 403. Guide pulley; 404. Cylinder; 405. Fixed bracket;

[0046] 601. Low-frequency transmitting transducer; 602. Medium-frequency transmitting transducer;

[0047] 901. Power component; 902. Rotating component; 903. First connecting rod; 904. Second connecting rod; 905. Pressure sensor; 906. Slide rail. Detailed Implementation

[0048] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0049] In the description of this invention, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0050] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0051] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0052] The terms “system,” “unit,” and “module” used in this article are methods for distinguishing different components, elements, parts, sections, or assemblies at different levels. These terms may be replaced by other expressions that achieve the same purpose.

[0053] like Figures 1-8As shown, in one embodiment of the in-situ measurement system and method for low-frequency acoustic properties of seabed sediments according to the present invention, the in-situ measurement system for low-frequency acoustic properties of seabed sediments includes a main frame 1, a probe 2, a penetration mechanism 3, a swing arm mechanism 9, and a control cabin; wherein, the main frame 1 includes an upper end face, a lower end face, and a support frame, the two ends of the support frame respectively enclosing the periphery of the upper end face and the periphery of the lower end face, and the upper end face is used for connection with the hull; a column 101 is provided in the middle of the main frame 1, and the column 101 is vertically connected to the upper end face and the lower end face; the probe 2 is detachably connected to the column 101, the probe 2 is slidably connected to the column 101 and can be vertically raised and lowered relative to the column 101 for penetrating the seabed sediments, and a receiving transducer 8 capable of receiving low-frequency sound waves is installed at the end of the probe 2 near the seabed sediments; the probe 2 includes a sampling probe or a geological probe for measurement work. During operation, a sampling probe or a geological probe is selected based on the characteristics of the seabed sediments. The penetration mechanism 3 is detachably connected to the column 101 and slidably connected to the column 101 to provide power for the probe 2 to penetrate the seabed sediments. The penetration mechanism 3 includes a vibratory penetration mechanism or a water jet drilling mechanism. When the sampling probe is selected for the measurement work, the vibratory penetration mechanism is installed; when the geological probe is selected for the measurement work, the water jet drilling mechanism is installed. The swing arm mechanism 9 is fixedly connected to the main frame 1. The swing arm mechanism 9 is equipped with a rotatable first connecting rod 903. The first connecting rod 903 is equipped with a transmitting transducer 6 that can emit medium and low frequency sound waves. During the measurement work, the first connecting rod 903 rotates to a horizontal direction perpendicular to the probe 2. The control cabin is fixedly connected to the main frame 1 and is communicatively connected to the receiving transducer 8 and the transmitting transducer 6, respectively, to control the receiving transducer 8 and the transmitting transducer 6.

[0054] In the above illustrative embodiments, the in-situ measurement system for low-frequency acoustic characteristics of seabed sediments can select appropriate probes 2 and penetration mechanisms 3 according to different types of seabed sediments, which has strong adaptability, can perform effective measurements in various environments, and can improve the penetration efficiency of the measurement system, thereby improving the overall measurement efficiency.

[0055] In some embodiments, such as Figure 4 As shown, two columns 101 are provided to improve the stability of the lifting and lowering of the probe 2 and the penetration mechanism 3. By setting two columns 101, the support points of the system are increased, making the probe 2 and the penetration mechanism 3 more stable during the lifting and lowering process, reducing the possibility of swaying and deviation, thereby improving the accuracy of the measurement.

[0056] In some embodiments, such as Figure 4As shown, a limiting plate 102 is provided on the lower end face of the main frame 1 to limit the position of the probe 2. The limiting plate 102 effectively limits the position of the probe 2, prevents the probe 2 from deviating during the penetration process, and ensures that the probe 2 always stays on the predetermined track, thereby improving the accuracy and reliability of the measurement.

[0057] In some embodiments, such as Figure 1 As shown, a detachable sliding connector 301 is provided at the connection between the penetration mechanism 3 and the column 101. The sliding connector 301 is sleeved on the outer periphery of the column 101, and the penetration mechanism 3 is slidably connected to the column 101 through the sliding connector 301. The sliding connector 301 allows for easy disassembly and installation of the penetration mechanism 3, improving the system's flexibility and ease of maintenance, while also ensuring the stability of the penetration mechanism 3 during use.

[0058] In some embodiments, such as Figure 1 As shown, a load-bearing head 11 is provided above the upper end face of the main frame 1, which is used to connect the cable of the survey vessel. Specifically, the survey vessel is equipped with a winch for raising and lowering the cable, and the surveyors raise and lower the cable to retrieve or lower the in-situ measurement system for the low-frequency acoustic characteristics of seabed sediments.

[0059] In some embodiments, such as Figure 1 As shown, a camera 10 is installed on the support frame of the main frame 1. The camera 10 is used to observe the measurement process. Specifically, the camera 10 is used to observe the lowering process of the in-situ measurement system to see if the in-situ measurement system is close to the seabed. When it is close to the seabed, the measurement personnel slow down the lowering speed in advance to avoid damage to the device. The camera 10 can also be used for the entire measurement process, such as the penetration process of the probe 2 and the retraction process of the probe 2.

[0060] In some embodiments, such as Figure 8 As shown, the sampling probe is hollow inside, and a sampling port is provided at the end of the sampling probe. When the sampling probe penetrates the seabed sediment, some seabed sediment enters the interior of the sampling probe through the sampling port to complete the sampling. The vibration penetration mechanism is installed at the end of the sampling probe away from the sampling drill bit 211. The vibration penetration mechanism includes at least one pair of vibration motors 321, which drive the sampling probe to move vertically downward.

[0061] Furthermore, such as Figure 8As shown, the sampling probe includes a sampling drill bit 211, a sampling tube 212, and an outer tube 213. The sampling drill bit 211 is located at the end of the outer tube 213 and has a sampling port. The sampling tube 212 is fitted inside the outer tube 213, with one end of the sampling tube 212 open near the sampling drill bit 211. The vibration penetration mechanism also includes a pair of eccentric wheels 322 mounted on the output shaft of the vibration motor 321. As an illustrative embodiment, the vibration penetration mechanism includes a pair of vibration motors 321, which rotate synchronously in the forward and reverse directions, respectively, driving the two eccentric wheels 322 to rotate synchronously in the forward and reverse directions. The centrifugal forces generated by the two eccentric wheels 322 are equal in magnitude and opposite in direction in the horizontal direction, canceling each other out. They are equal in magnitude and the same in direction in the vertical direction, superimposing each other to generate a downward thrust. This drives the sampling probe to move vertically downward, and the sampling probe carries the receiving transducer 8 into the seabed sediment, simultaneously sampling the seabed sediment.

[0062] In some embodiments, such as Figure 7 As shown, a geological drill bit 221 is provided at the end of the geological probe rod, and a sleeve 222 is provided on the outer periphery of the geological probe rod. A flushing gap is provided between the geological probe rod and the sleeve 222. A water jet drilling mechanism is installed at the end of the geological probe rod away from the geological drill bit 221. The water jet drilling mechanism includes a rotary motor 311 and a high-pressure water pump 312. The outlet of the high-pressure water pump 312 is connected to the flushing gap. The rotary motor 311 drives the geological probe rod to move vertically downward, and the high-pressure water pump 312 is used to inject water into the flushing gap to clean the geological probe rod.

[0063] Furthermore, such as Figure 7 As shown, flushing gaps are provided between the sleeve 222 and the geological probe rod, and between the sleeve 222 and the geological drill bit 221. An opening is provided at the end of the sleeve 222 furthest from the geological drill bit 221, and the outlet of the high-pressure water pump 312 is connected to this opening. When the water jet drilling mechanism is working, the rotary motor 311 drives the geological probe rod to move vertically downwards, carrying the receiving transducer into the seabed sediment. Simultaneously, the high-pressure water pump 312 injects water into the flushing gaps through the opening of the sleeve 222. Figure 7 The dashed line indicates the direction of water flow. Water enters the high-pressure water pump 312 through the inlet and flows through the outlet to the opening of the sleeve 222, passing through the flushing gap to wash away seabed sediments adhering to the geological probe. The geological probe and water jet drilling mechanism are more suitable for seabed sediments with larger particles, higher hardness, and looser texture. The geological probe is harder and can penetrate into hard seabed sediments, while larger, looser seabed sediments tend to adhere to the probe 2, affecting its penetration efficiency. The water jet drilling mechanism flushes the probe 2 while it is penetrating, effectively reducing the impact of adsorbed material.

[0064] In some embodiments, such as Figure 6As shown, the swing arm mechanism 9 also includes a rotating component 902 and a slide rail 906. The slide rail 906 is fixedly connected to the rotating component 902 and rotates with the rotating component 902. The first connecting rod 903 is vertically slidably connected to the slide rail 906 and rotates with the rotating component 902 and the slide rail 906. When the first connecting rod 903 rotates to a horizontal direction perpendicular to the probe rod 2, the first connecting rod 903 slides vertically along the slide rail 906 to adjust the relative height between the transmitting transducer 6 and the seabed sediment.

[0065] In some embodiments, such as Figure 6 As shown, the swing arm mechanism 9 also includes a second link 904, which is connected to the end of the first link 903 away from the slide rail 906. A pressure sensor 905 is mounted on the second link 904. When the first link 903 rotates to a horizontal direction perpendicular to the probe 2, the sensing surface of the pressure sensor 905 is at the same height as the lowest point of the transmitting transducer 6. The pressure sensor 905 is used to assist in detecting the pressure on the transmitting transducer 6 to determine whether the relative height between the transmitting transducer 6 and the seabed sediment is appropriate. By setting the pressure sensor 905, the pressure on the transmitting transducer 6 is monitored in real time, ensuring good contact between the transmitting transducer 6 and the seabed sediment, and ensuring that the entire propagation process of the sound wave signal is completed in the seabed sediment, thereby effectively reducing measurement errors.

[0066] In some embodiments, such as Figure 6 As shown, the swing arm structure also includes a power component 901, which is fixed to the bottom of the main frame 1 and provides power for the rotation and sliding of the first connecting rod 903. Specifically, the power component 901 includes a hydraulic cylinder connected to a rotating shaft, and a rotating component 902 is sleeved on the rotating shaft. When the swing arm mechanism 9 is working, the power component 901 provides power to drive the rotating shaft to rotate. The first connecting rod 903 rotates around the rotating shaft through the rotating component 902. After the first connecting rod 903 rotates to the horizontal direction, it slides vertically along the slide rail 906 to adjust the relative height between the transmitting transducer 6 and the seabed sediment. During the sliding process, a pressure sensor 905 is used to assist in detecting the pressure on the transmitting transducer 6 until the transmitting transducer 6 and the seabed sediment reach a suitable relative height, ensuring good contact between the transmitting transducer 6 and the seabed sediment, while avoiding damage to the transmitting transducer 6 due to excessive pressure.

[0067] In some embodiments, such as Figure 2 As shown, the in-situ measurement system for low-frequency acoustic properties of seabed sediments also includes a traction mechanism 4, which is fixedly installed within the main frame 1. The traction mechanism 4 includes a traction rope 402, one end of which is connected to the probe rod 2 for pulling or lifting the probe rod 2. The traction mechanism 4 makes the operation of the probe rod 2 more convenient, allowing for easy lifting of the probe rod 2.

[0068] In some embodiments, such as Figure 5 As shown, the traction mechanism 4 also includes a winch 401, which is fixedly connected to the main frame 1. The other end of the traction rope 402 is wound around the winch 401, and the winch 401 is used to wind up and down the traction rope 402. The winch 401 makes the winding and unwinding of the traction rope 402 more efficient, facilitating the operation and management of the measurement system.

[0069] In some embodiments, such as Figure 5 As shown, the traction mechanism 4 also includes a guide pulley 403, which is fixed below the upper end face of the main frame 1. One end of the traction rope 402 passes over the guide pulley 403 and is connected to the probe rod 2. The guide pulley 403 makes the traction work more labor-saving and ensures that the movement trajectory of the traction rope 402 is more accurate.

[0070] Furthermore, such as Figure 5 As shown, the traction mechanism 4 also includes a cylinder 404 that provides power to the winch 401, and the cylinder 404 is connected to the winch 401. The cylinder 404 provides reliable power support to the winch 401, ensuring the smooth operation of the traction rope 402 during its winding and unwinding process.

[0071] In some embodiments, such as Figure 5 As shown, the traction mechanism 4 also includes a fixed bracket 405, which is fixed within the main frame 1 and respectively fixedly connected to the cylinder 404 and the winch 401. The fixed bracket 405 ensures a stable connection between the various components of the traction mechanism 4, improving the overall stability and reliability of the system.

[0072] In some embodiments, such as Figure 1 As shown, multiple transmitting transducers 6 are provided, including intermediate frequency transmitting transducers 6602 and low frequency transmitting transducers 6601. As an illustrative embodiment, a low frequency transmitting transducer 6601 is provided at the end of the first connecting rod 903, and five intermediate frequency transmitting transducers 6602 are provided in the middle.

[0073] Furthermore, such as Figure 1 As shown, there are multiple receiving transducers 8, and multiple receiving transducers 8 are sleeved with probe rod 2.

[0074] In some embodiments, the in-situ measurement system for low-frequency acoustic properties in seabed sediments further includes a host computer, which is communicatively connected to the control cabin. The host computer is used to preset and send acoustic signal parameters emitted by the transmitting transducer 6, including waveform type, frequency, number of cycles, amplitude, etc., and to select the channel of the transmitting transducer 6.

[0075] Furthermore, such as Figure 3As shown, the control cabin includes a launch control cabin 5 and a receiver control cabin 7, which are communicatively connected. The launch control cabin 5 controls multiple transmitting transducers 6 and transmits acoustic signals according to preset parameters from the host computer. Simultaneously, the launch control cabin 5 is also communicatively connected to a swing arm mechanism 9, used to receive commands from the host computer to open the swing arm mechanism 9 and control the first connecting rod 903 to rotate and open. The receiver control cabin 7 controls multiple receiving transducers 8 and is communicatively connected to a penetration mechanism 3, used to receive penetration commands from the host computer and control the penetration mechanism 3 to open, driving the probe 2 to penetrate the seabed sediment. The receiver control cabin 7 is also communicatively connected to a traction mechanism 4, used to receive retrieval commands from the host computer and control the traction mechanism 4 to operate, pulling the probe 2 out of the seabed sediment for retrieval.

[0076] In some embodiments, such as Figure 3 As shown, a power supply 12 is installed on the lower end face of the main frame 1. The power supply 12 is electrically connected to the control cabin, the penetration mechanism 3, the swing arm mechanism 9, the traction mechanism 4, the transmitting transducer 6, and the receiving transducer 8, respectively, and is used to power the in-situ measurement system for the low-frequency acoustic characteristics of seabed sediments.

[0077] In some embodiments, the length of the probe 2 is not less than 3m. The length of the first connecting rod 903 is set as needed, with the principle being to ensure that the distance between the connecting lines between each transmitting transducer 6 and the receiving transducer 8 is greater than 4m, in order to meet the measurement requirements of mid-to-low frequency acoustic characteristics.

[0078] Based on the aforementioned in-situ measurement system for low-frequency acoustic characteristics of seabed sediments, this invention also provides an in-situ measurement method for low-frequency acoustic characteristics of seabed sediments. This in-situ measurement method, applied to the aforementioned in-situ measurement system for low-frequency acoustic characteristics of seabed sediments, includes the following steps:

[0079] S1. Based on the characteristics of seabed sediments in the exploration area, select the appropriate probe 2 and penetration mechanism 3, and install the in-situ measurement system.

[0080] In this step, the probe 2 is connected to the penetration mechanism 3, and the sliding connector 301 is connected to the penetration mechanism 3. The sliding connector 301 is then fixed to the column 101 of the main frame 1. The probe 2 and penetration mechanism 3 are selected primarily based on the hardness and density of the seabed sediments. For seabed sediments with larger particles, higher hardness, and looser texture, such as silty sand, a geological probe and a water jet drilling mechanism are selected for installation. For seabed sediments with smaller particles, higher density, and lower hardness, such as sandy silt, a sampling probe and a vibratory penetration mechanism are selected for installation.

[0081] S2, lower the in-situ measurement system to the seabed sediment, and use the swing arm mechanism 9 to rotate the first connecting rod 903 to the horizontal direction;

[0082] In this step, the surveyors lower the in-situ measurement system by lowering the cable connected to the ship's winch. Simultaneously, camera 10 monitors the lowering height of the in-situ measurement system. The lowering speed is slowed as the in-situ measurement system approaches the seabed. The process of the swing arm mechanism 9 rotating the first link 903 to a horizontal position includes: the power key of the swing arm mechanism 9 provides rotational power to the rotating shaft, which carries the slide rail 906 and the first link 903 to rotate until the first link 903 is rotated to a horizontal position. Then, the first link 903 slides vertically up and down along the slide rail 906 to adjust the relative height between the transmitting transducer 6 and the seabed sediment. During the sliding process, pressure sensor 905 assists in detecting the pressure on the transmitting transducer 6 until the transmitting transducer 6 makes good contact with the seabed sediment, while avoiding damage to the transmitting transducer 6 due to excessive pressure.

[0083] S3, using the penetration mechanism 3 to drive the probe 2 to penetrate the seabed sediment to a preset depth;

[0084] In this step, when the penetration mechanism 3 adopts a vibratory penetration mechanism, the vibration motor 321 of the penetration mechanism 3 drives the sampling probe to move vertically downward. The sampling probe carries the receiving transducer 8 into the seabed sediment and samples the seabed sediment at the same time. When the penetration mechanism 3 adopts a water jet drilling mechanism, the rotary motor 311 drives the geological probe to move vertically downward. The geological probe carries the receiving transducer into the seabed sediment. At the same time, the high-pressure water pump 312 injects water into the flushing gap through the opening of the sleeve 222 to flush the seabed sediment adhering to the geological probe.

[0085] S4, the control cabin controls the transmitting transducer 6 to emit a sound wave signal with preset parameters, and controls the receiving transducer 8 to receive the sound wave signal, while recording the emitted and received sound wave signals respectively.

[0086] In this step, the host computer presets the acoustic signal parameters and selects the channel of the transmitting transducer 6. Multiple transmitting transducers 6 or just one can be selected simultaneously. After the host computer sends a command to the transmitting control cabin 5, the transmitting control cabin 5 controls the transmitting transducer 6 to emit the acoustic signal with the preset parameters; the receiving control cabin 7 controls the receiving transducer 8 to operate. At this time, the probe rod 2 and the first connecting rod 903 are in a vertical state, and the receiving transducer 8 and the transmitting transducer 6 installed on the probe rod 2 and the first connecting rod 903 meet the conditions for oblique measurement.

[0087] S5. Repeat steps S3-S4 to obtain the acoustic characteristics of acoustic signals with different parameters in seabed sediments at different depths.

[0088] In this step, the acoustic characteristics are calculated as follows: Let the transmitting transducer 6 emit a sound wave signal of a certain frequency (f) and amplitude A1 at time T1. Let the time for the sound wave signal to reach the receiving transducer 8 be T2 and the amplitude be a2. The sound velocity V of the sound wave signal in the sediment can be calculated according to equation (1), and the sound attenuation coefficient α of the sound wave in the sediment can be calculated using equation (2). The expression of equation (1) is:

[0089]

[0090] The expression for equation (2) is:

[0091]

[0092] S6, lift the in-situ measurement system upwards to a certain distance away from the seabed;

[0093] In this step, the in-situ measurement system is lifted up to 5m above the seabed.

[0094] S7. Repeat step S4 to obtain the acoustic characteristics of sound wave signals with different parameters in water at different depths.

[0095] In the above illustrative embodiments, by first measuring the acoustic characteristics of seabed sediments and then using an in-situ measurement system to measure the acoustic characteristics of the water near the seabed sediments, more sufficient data support can be provided for correcting and interpreting the acoustic characteristics data of seabed sediments, thereby improving the accuracy and reliability of the measurement.

[0096] In some embodiments, step S2 further includes sliding the first link 903 vertically along the slide rail 906 to adjust the relative height of the transmitting transducer 6 and the seabed sediment.

[0097] In some embodiments, step S6 further includes using a traction rope 402 to pull the probe 2 upwards, lifting the probe 2 from the seabed sediment; in step S7, before repeating step S4, the probe 2 is driven down to a preset depth using the penetration mechanism 3. The step of using the traction rope 402 to pull the probe 2 upwards includes: using a cylinder 404 to drive the winch 401 to rotate, and the traction rope 402 pulls the penetration mechanism 3 upwards via the guide pulley 403, thereby lifting the probe 2. It should be noted that during the process of the probe 2 penetrating the seabed sediment, the traction rope 402 is stretched by the penetration mechanism 3.

[0098] In some embodiments, in step S6, the in-situ measurement system is raised to a distance of 5m from the seabed. By raising the in-situ measurement system by 5m, when the probe 2 is lowered, the bottom of the probe 2 is 2m away from the seabed, which can effectively measure the acoustic characteristics of the water near the seabed sediments.

[0099] In some embodiments, the in-situ measurement method of low-frequency acoustic properties in seabed sediments further includes: S8, analyzing and comparing the sound velocity and sound attenuation coefficient of the sound wave signal in seabed sediments and water bodies.

[0100] Through the description of several embodiments of the in-situ measurement system and method for low-frequency acoustic properties in seabed sediments of the present invention, it can be seen that the embodiments of the in-situ measurement system and method for low-frequency acoustic properties in seabed sediments of the present invention have at least one or more of the following advantages:

[0101] 1. The in-situ measurement system for low-frequency acoustic characteristics of seabed sediments provided by the present invention can select appropriate probes 2 and penetration mechanisms 3 according to different types of seabed sediments, which has strong adaptability, can effectively measure in a variety of environments, and can improve the penetration efficiency of the measurement system, thereby improving the overall measurement efficiency.

[0102] 2. The in-situ measurement system for low-frequency acoustic characteristics of seabed sediments provided by the present invention monitors the pressure on the transmitting transducer 6 in real time through the setting of pressure sensor 905, ensuring good contact between the transmitting transducer 6 and the seabed sediments, and ensuring that the entire propagation process of the sound wave signal is completed in the seabed sediments, thereby effectively reducing measurement errors.

[0103] 3. The in-situ measurement method for low-frequency acoustic properties of seabed sediments provided by the present invention first measures the acoustic properties of seabed sediments, and then improves the in-situ measurement system to measure the acoustic properties of the water body near the seabed sediments. This method can provide more sufficient data support for correcting and interpreting the acoustic property data of seabed sediments, and improve the accuracy and reliability of the measurement.

[0104] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0105] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An in-situ measurement system for low-frequency acoustic properties of seabed sediments, characterized in that, include: The main frame includes an upper end face, a lower end face, and a support frame. The two ends of the support frame are respectively enclosed around the periphery of the upper end face and the periphery of the lower end face. The upper end face is used to connect with the hull. A column is provided in the middle of the main frame, and the column is vertically connected to the upper end face and the lower end face. A probe rod, detachably connected to a column, is slidably connected to the column and can be vertically raised and lowered relative to the column. It is used to penetrate seabed sediments. A transducer capable of receiving low-to-medium frequency sound waves is installed at the end of the probe rod closest to the seabed sediment. The probe rod can be either a sampling probe rod or a geological probe rod; the choice of which depends on the characteristics of the seabed sediment during measurement. The sampling probe rod is hollow inside, with a sampling port at its end. When the sampling probe rod penetrates the seabed sediment, some seabed sediment enters the sampling probe rod through the sampling port, completing the sampling. A vibratory penetrator is also included. The sampling probe rod is installed at the end away from the sampling drill bit. The vibration penetration mechanism includes at least one pair of vibration motors, which drive the sampling probe rod to move vertically downward. The end of the geological probe rod is provided with a geological drill bit, and a sleeve is provided on the outer periphery of the geological probe rod. A flushing gap is provided between the geological probe rod and the sleeve. The water jet drilling mechanism is installed at the end of the geological probe rod away from the geological drill bit. The water jet drilling mechanism includes a rotary motor and a high-pressure water pump. The outlet of the high-pressure water pump is connected to the flushing gap. The rotary motor drives the geological probe rod to move vertically downward, and the high-pressure water pump is used to inject water into the flushing gap to clean the geological probe rod. The penetration mechanism is detachably connected to and slidably connected to the column, and is used to provide power for the probe to penetrate the seabed sediment; the penetration mechanism includes a vibratory penetration mechanism or a water jet drilling mechanism. When a sampling probe is selected for the measurement work, a vibratory penetration mechanism is installed; when a geological probe is selected for the measurement work, a water jet drilling mechanism is installed. The swing arm mechanism is fixedly connected to the main frame. It includes a rotatable first link with a transducer capable of emitting low-to-medium frequency sound waves. During measurement, the first link rotates to a horizontal position perpendicular to the probe. The mechanism also includes a rotating component and a slide rail. The slide rail is fixedly connected to the rotating component and rotates with it. The first link is slidably connected to the slide rail and rotates with both the rotating component and the slide rail. When the first link rotates to a horizontal position perpendicular to the probe, it slides vertically along the slide rail to adjust the relative height between the transducer and the seabed sediment. The mechanism also includes a second link connected to the end of the first link furthest from the slide rail. A pressure sensor is mounted on the second link. When the first link rotates to a horizontal position perpendicular to the probe, the sensing surface of the pressure sensor is at the same height as the lowest point of the transducer. The pressure sensor is used to assist in detecting the pressure on the transducer to determine if the relative height between the transducer and the seabed sediment is appropriate. The control cabin is fixedly connected to the main frame and is communicatively connected to the receiving transducer and the transmitting transducer, respectively, for controlling the receiving transducer and the transmitting transducer.

2. The in-situ measurement system for low-frequency acoustic properties of seabed sediments according to claim 1, characterized in that, It also includes a traction mechanism, which is fixedly installed within the main frame. The traction mechanism includes a traction rope, one end of which is connected to the probe rod for pulling or lifting the probe rod.

3. The in-situ measurement system for low-frequency acoustic properties of seabed sediments according to claim 2, characterized in that, The traction mechanism also includes a winch, which is fixedly connected to the main frame. The other end of the traction rope is wound around the winch, which is used to raise and lower the traction rope.

4. An in-situ measurement method for low-frequency acoustic properties in seabed sediments, characterized in that, Applied to the in-situ measurement system as described in any one of claims 1-3, Includes the following steps: S1. Based on the characteristics of seabed sediments in the exploration area, select the appropriate probe and penetration mechanism, and install the in-situ measurement system. S2, lower the in-situ measurement system to the seabed sediment and use the swing arm mechanism to rotate the first link to the horizontal direction; S3, using the penetration mechanism to drive the probe to penetrate the seabed sediment to a preset depth; S4, the control cabin controls the transmitting transducer to emit acoustic signals with preset parameters, and controls the receiving transducer to receive acoustic signals, while recording the emitted and received acoustic signals respectively. S5. Repeat steps S3-S4 to obtain the acoustic characteristics of acoustic signals with different parameters in seabed sediments at different depths. S6, lift the in-situ measurement system upwards to a certain distance away from the seabed; S7. Repeat step S4 to obtain the acoustic characteristics of sound wave signals with different parameters in water at different depths.

5. The in-situ measurement method for low-frequency acoustic properties of seabed sediments according to claim 4, characterized in that, Step S2 also includes sliding the first link vertically along the slide rail to adjust the relative height of the transmitting transducer and the seabed sediment.

6. The in-situ measurement method for low-frequency acoustic properties of seabed sediments according to claim 4, characterized in that, Step S6 also includes using a traction rope to pull the probe upwards and lift it from the seabed sediment; in step S7, before repeating step S4, the probe is driven down to a preset depth using a penetration mechanism.

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