In-situ measurement system for low-and-medium-frequency acoustic characteristics of submarine sediments

Abstract

The utility model relates to an in-situ measurement system for low-and-medium-frequency acoustic characteristics of submarine sediments, which belongs to the technical field of submarine sediment measurement equipment and comprises a main body frame, a probe rod, a swing arm mechanism and a control cabin. Wherein the probe rod is arranged in the main body frame and is used for penetrating into seabed sediments; a plurality of receiving transducers capable of receiving low and medium frequency sound waves are mounted at one end, close to the seabed sediment, of the probe rod; the swing arm mechanism is fixedly connected with the main body frame, the swing arm mechanism is provided with a rotatable first connecting rod, the first connecting rod is provided with a plurality of transmitting transducers, the transmitting transducers comprise intermediate-frequency transmitting transducers and low-frequency transmitting transducers, and during measurement, the first connecting rod rotates to the horizontal direction perpendicular to the probe rod. The in-situ measurement system can measure the acoustic characteristics of multiple frequency sound waves in the seabed sediment at the same time, reduces the time and cost of multiple measurements, and improves the measurement efficiency.

Description

Technical Field

[0001] The utility model belongs to the technical field of subsea sediment measurement equipment, and particularly relates to an in-situ measurement system for low-frequency acoustic characteristics in subsea sediments. Background Technique

[0002] The measurement and research of the acoustic characteristics of subsea sediments have important application values in military, marine science and production fields such as ocean acoustic field prediction, underwater target detection, underwater communication and navigation, seabed topography mapping, and seabed resource exploration. The acoustic characteristics of subsea sediments mainly refer to two acoustic parameters: the propagation speed (sound velocity) of sound waves with different frequencies in the sediments and the absorption of sound wave energy by the sediments (sound attenuation coefficient). Affected by the subsea environmental temperature, pressure, and sediment complexity, and combined with the sound wave attenuation and dispersion effects when low- and medium-frequency sound waves propagate in the sediments, the measurement of low- and medium-frequency sound waves in subsea sediments is very difficult.

[0003] In the prior art, Chinese invention patent application CN111103622A discloses an in-situ measurement system and method for low-frequency acoustic characteristics in subsea sediments. This patent realizes the measurement of low- and medium-frequency sound waves in subsea sediments through a low- and medium-frequency transmitting transducer and two broadband receiving transducers. However, due to the need to use a lifting oil cylinder for the lifting of the transmitting transducer in this patent, restricted by the structure of the in-situ measurement system, only one transmitting transducer can be installed in this system, which results in only being able to measure the acoustic characteristics of sound waves with a single frequency in subsea sediments at a single time and unable to simultaneously measure sound waves with multiple frequencies.

[0004] Therefore, how to solve the technical problem of simultaneously measuring the acoustic characteristics of sound waves with multiple frequencies in subsea sediments is a technical problem that urgently needs to be solved at present. Content of the Utility Model

[0005] Aiming at the deficiencies existing in the prior art, the utility model provides an in-situ measurement system for low-frequency acoustic characteristics in subsea sediments. By installing multiple receiving transducers and transmitting transducers on the probe rod and the swing arm mechanism, the acoustic characteristics of sound waves with multiple frequencies in subsea sediments can be measured simultaneously, solving the problem in the prior art that only a single frequency of sound wave can be measured at a single time.

[0006] The utility model provides an in-situ measurement system for low-frequency acoustic characteristics in subsea sediments, including:

[0007] A main body frame;

[0008] A probe rod, which is installed inside the main body frame, is slidably connected to the main body frame and can be vertically lifted relative to the main body frame for penetrating into subsea sediments; multiple receiving transducers capable of receiving low- and medium-frequency sound waves are installed at one end of the probe rod close to the subsea sediments;

[0009] A swing arm mechanism, which is fixedly connected to the main body frame. The swing arm mechanism is provided with a rotatable first connecting rod, and a plurality of transmitting transducers are installed on the first connecting rod. The plurality of transmitting transducers include intermediate-frequency transmitting transducers and low-frequency transmitting transducers. When performing measurement work, the first connecting rod rotates to a horizontal direction perpendicular to the probe rod.

[0010] A control cabin, which is fixedly connected to the main body frame and is respectively communicatively connected to a plurality of receiving transducers and a plurality of transmitting transducers, and is used to control the plurality of receiving transducers and the plurality of transmitting transducers.

[0011] In this technical solution, by installing a plurality of receiving transducers and transmitting transducers on the probe rod and the swing arm mechanism, the acoustic properties of sound waves with multiple frequencies in the seafloor sediment can be measured simultaneously, solving the problem in the prior art that only a single frequency sound wave can be measured once; reducing the time and cost of multiple measurements and improving the measurement efficiency.

[0012] In some embodiments, the swing arm mechanism further includes a rotating member and a slide rail. The slide rail is fixedly connected to the rotating member and rotates with the rotating member. The first connecting rod is vertically slidably connected to the slide rail and rotates with the rotating member and the slide rail; when the first connecting rod rotates to a horizontal direction perpendicular to the probe rod, the first connecting rod vertically slides along the slide rail to adjust the relative height between the transmitting transducer and the seafloor sediment.

[0013] In some embodiments, the swing arm mechanism further includes a second connecting rod, and the second connecting rod is connected to one end of the first connecting rod away from the slide rail; a pressure sensor is installed on the second connecting rod. When the first connecting rod rotates to a horizontal direction perpendicular to the probe rod, 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 received by the transmitting transducer to judge whether the relative height between the transmitting transducer and the seafloor sediment is appropriate. Through the setting of the pressure sensor in this technical solution, the pressure received by the transmitting transducer is monitored in real time to ensure good contact between the transmitting transducer and the seafloor sediment.

[0014] In some embodiments, the probe rod is detachably connected to the main body frame. The probe rod includes a sampling probe rod or a geological probe rod. When performing measurement work, the sampling probe rod or the geological probe rod is selected for installation according to the characteristics of the seafloor sediment.

[0015] In some embodiments, the in-situ measurement system for the low-frequency acoustic properties in the seafloor sediment further includes a penetration mechanism. The penetration mechanism is detachably connected to the inside of the main body frame. The penetration mechanism is slidably connected to the active frame and is connected to the probe rod, and is used to provide the power for the probe rod to penetrate into the seafloor sediment; the penetration mechanism includes a vibration penetration mechanism or a water jet drilling mechanism. When the sampling probe rod is selected for measurement work, the vibration penetration mechanism is installed; when the geological probe rod is selected for measurement work, the water jet drilling mechanism is installed.

[0016] In some of these 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 into the seabed sediment, part of the seabed sediment enters the inside of the sampling probe through the sampling port to complete the sampling; the vibration penetration mechanism is installed at one end of the sampling probe away from the sampling drill bit. The vibration penetration mechanism includes at least a pair of vibration motors, and the vibration motors are used to drive the sampling probe to move vertically downward.

[0017] In some of these embodiments, a geological drill bit is provided at the end of the geological probe, a sleeve is provided on the outer periphery of the geological probe, and a flushing gap is provided between the geological probe and the sleeve; the water jet drilling mechanism is installed at one 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 water 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.

[0018] In some of these embodiments, the in-situ measurement system for the low-frequency acoustic characteristics in seabed sediments further includes a traction mechanism. The traction mechanism is fixedly installed inside the main frame. The traction mechanism includes a traction rope, and one end of the traction rope is connected to the probe for towing or lifting the probe. With the setting of the traction mechanism in this technical solution, the operation of the probe is more convenient, and the lifting of the probe can be easily achieved.

[0019] In some of these embodiments, the traction mechanism further includes a winch. The winch is fixedly connected to the main frame, and the other end of the traction rope is wound around the winch. The winch is used to take in and release the traction rope. With the setting of the winch in this technical solution, the taking in and releasing of the traction rope is more efficient, facilitating the operation and management of the measurement system.

[0020] In some of these embodiments, the traction mechanism further includes a guide pulley. The guide pulley is fixed to the upper part of the main frame, and one end of the traction rope bypasses the guide pulley and is connected to the probe. With the setting of the guide pulley in this technical solution, the traction work is more labor-saving, and at the same time, it ensures that the movement trajectory of the traction rope is more accurate.

[0021] Based on the above solutions, the in-situ measurement system for the low-frequency acoustic characteristics in seabed sediments in the embodiments of the present utility model can simultaneously measure the acoustic characteristics of sound waves at multiple frequencies in seabed sediments, reducing the time and cost of multiple measurements and improving the measurement efficiency; and through the collaborative work of multiple receiving transducers and transmitting transducers, more accurate and comprehensive acoustic characteristic data can be obtained, improving the reliability of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present utility model and constitute a part of this application. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0023] Figure 1 Schematic diagram of the working state structure of the in-situ measurement system for low-frequency acoustic properties in seabed sediments in the embodiment of the present utility model;

[0024] Figure 2 Schematic diagram of the storage state structure of the in-situ measurement system for low-frequency acoustic properties in seabed sediments in the embodiment of the present utility model;

[0025] Figure 3 Exploded view of the structure of the in-situ measurement system for low-frequency acoustic properties in seabed sediments in the embodiment of the present utility model;

[0026] Figure 4 Schematic diagram of the structure of the main frame;

[0027] Figure 5 Schematic diagram of the structure of the traction mechanism;

[0028] Figure 6 Schematic diagram of the structure of the swing arm mechanism;

[0029] Figure 7 Schematic diagram of the structure of the water jet drilling mechanism and the geological drill rod;

[0030] Figure 8 Schematic diagram of the structure of the vibration penetration mechanism and the sampling drill rod.

[0031] In the figure:

[0032] 1. Main frame; 2. Drill rod; 3. Penetration mechanism; 4. Traction mechanism; 5. Transmitting control cabin; 6. Transmitting transducer; 7. Receiving control cabin; 8. Receiving transducer; 9. Swing arm mechanism; 10. Camera; 11. Load-bearing head; 12. Power supply;

[0033] 101. Column; 102. Limiting plate;

[0034] 211. Sampling bit; 212. Sampling tube; 213. Outer tube; 221. Geological bit; 222. Sleeve;

[0035] 301. Sliding connector; 311. Rotary motor; 312. High-pressure water pump; 321. Vibration motor; 322. Eccentric wheel;

[0036] 401. Winch; 402. Traction rope; 403. Guide pulley; 404. Cylinder barrel; 405. Fixed bracket;

[0037] 601. Low-frequency transmitting transducer; 602. Medium-frequency transmitting transducer;

[0038] 901. Power component; 902. Rotating component; 903. First connecting rod; 904. Second connecting rod; 905. Pressure sensor; 906. Slide rail. Detailed implementation manners

[0039] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0040] In the description of the present utility model, it should be understood that the terms "center", "transverse", "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 drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0041] The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0042] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0043] The terms "system", "unit", and "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels, and these terms can be replaced by other expressions that can achieve the same purpose.

[0044] As Figures 1 - 8As shown, in an embodiment of the in-situ measurement system for low-frequency acoustic properties of submarine sediments in the present utility model, the in-situ measurement system for low-frequency acoustic properties of submarine sediments includes a main frame 1, a sounding rod 2, a swing arm mechanism 9, and a control cabin; among them, the sounding rod 2 is installed inside the main frame 1, and the sounding rod 2 is slidably connected to the main frame 1 and can vertically lift relative to the main frame 1 for penetrating into the submarine sediments; a plurality of receiving transducers 8 capable of receiving medium and low-frequency sound waves are installed at one end of the sounding rod 2 close to the submarine sediments; the swing arm mechanism 9 is fixedly connected to the main frame 1, and the swing arm mechanism 9 is provided with a rotatable first connecting rod 903, and a plurality of transmitting transducers 6 are installed on the first connecting rod 903. The plurality of transmitting transducers 6 include an intermediate-frequency transmitting transducer 6602 and a low-frequency transmitting transducer 6601. When performing measurement work, the first connecting rod 903 rotates to a horizontal direction perpendicular to the sounding rod 2; the control cabin is fixedly connected to the main frame 1 and is respectively communicatively connected to the plurality of receiving transducers 8 and the plurality of transmitting transducers 6 for controlling the plurality of receiving transducers 8 and the plurality of transmitting transducers 6.

[0045] In the above-mentioned schematic embodiment, the in-situ measurement system for low-frequency acoustic properties of submarine sediments can measure the acoustic properties of sound waves of multiple frequencies in the submarine sediments by installing a plurality of receiving transducers 8 and transmitting transducers 6 on the sounding rod 2 and the swing arm mechanism 9, solving the problem in the prior art that only a single frequency sound wave can be measured once; reducing the time and cost of multiple measurements and improving the measurement efficiency; and through the collaborative work of the plurality of receiving transducers 8 and the plurality of transmitting transducers 6, more accurate and comprehensive acoustic property data can be obtained, improving the reliability of the measurement results.

[0046] In some embodiments, as Figure 1 shown, 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. The length of the sounding rod 2 is not less than 3 m. The length of the first connecting rod 903 is set as required, and the setting principle is to ensure that the distance between the connection lines of each transmitting transducer 6 and the receiving transducer 8 is greater than 4 m to meet the measurement requirements of low-frequency acoustic properties.

[0047] In some embodiments, as Figure 6 shown, the swing arm mechanism 9 further includes a rotating member 902 and a slide rail 906. The slide rail 906 is fixedly connected to the rotating member 902 and rotates with the rotating member 902. The first connecting rod 903 is vertically slidably connected to the slide rail 906 and rotates with the rotating member 902 and the slide rail 906; when the first connecting rod 903 rotates to a horizontal direction perpendicular to the sounding rod 2, the first connecting rod 903 vertically slides along the slide rail 906 to adjust the relative height between the transmitting transducer 6 and the submarine sediments.

[0048] Furthermore, as Figure 6As shown, the swing arm mechanism 9 further includes a second connecting rod 904, and the second connecting rod 904 is connected to one end of the first connecting rod 903 away from the slide rail 906; a pressure sensor 905 is installed on the second connecting rod 904. When the first connecting rod 903 rotates to the horizontal direction perpendicular to the sounding rod 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. Through the setting of the pressure sensor 905, the pressure on the transmitting transducer 6 is monitored in real time to ensure good contact between the transmitting transducer 6 and the seabed sediment, and to ensure that the entire propagation process of the acoustic signal is completed in the seabed sediment, thereby effectively reducing the measurement error.

[0049] In some embodiments, as Figure 6 shown, the swing arm structure further includes a power member 901. The power member 901 is fixed to the bottom of the main frame 1 and is used to provide the power for the rotation and sliding of the first connecting rod 903. Specifically, the power member 901 includes a hydraulic cylinder, and the hydraulic cylinder is connected with a rotating shaft. The rotating member 902 is sleeved on the rotating shaft. When the swing arm mechanism 9 works, the power member 901 provides power to drive the rotating shaft to rotate. The first connecting rod 903 rotates around the rotating shaft through the rotating member 902. After the first connecting rod 903 rotates to the horizontal direction, 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. During the sliding process, the pressure sensor 905 is used to assist in detecting the pressure on the transmitting transducer 6 until the relative height between the transmitting transducer 6 and the seabed sediment reaches an appropriate value, ensuring good contact between the transmitting transducer 6 and the seabed sediment, and at the same time avoiding damage to the transmitting transducer 6 due to excessive pressure.

[0050] In some embodiments, as Figure 3 shown, the sounding rod 2 is detachably connected to the main frame 1. The sounding rod 2 includes a sampling sounding rod or a geological sounding rod. When performing measurement work, a sampling sounding rod or a geological sounding rod is selected according to the characteristics of the seabed sediment.

[0051] In some embodiments, as Figure 3 shown, the in-situ measurement system for the low-frequency acoustic characteristics of seabed sediment further includes a penetration mechanism 3. The penetration mechanism 3 is detachably connected to the inside of the main frame 1. The penetration mechanism 3 is slidably connected to the active frame and is connected to the sounding rod 2, and is used to provide the power for the sounding rod 2 to penetrate into the seabed sediment; the penetration mechanism 3 includes a vibration penetration mechanism or a water jet drilling mechanism. When a sampling sounding rod is selected for the measurement work, a vibration penetration mechanism is installed; when a geological sounding rod is selected for the measurement work, a water jet drilling mechanism is installed.

[0052] In some embodiments, as Figure 8As shown, the sampling probe rod is hollow inside, and a sampling port is provided at the end of the sampling probe rod. When the sampling probe rod penetrates into the seabed sediment, part of the seabed sediment enters the inside of the sampling probe rod through the sampling port to complete the sampling; the vibration penetration mechanism is installed at one end of the sampling probe rod away from the sampling drill bit 211. The vibration penetration mechanism includes at least a pair of vibration motors 321, and the vibration motors 321 are used to drive the sampling probe rod to move vertically downward.

[0053] Further, as Figure 8 shown, the sampling probe rod includes a sampling drill bit 211, a sampling tube 212 and an outer tube 213; wherein, the sampling drill bit 211 is arranged at the end of the outer tube 213, the sampling drill bit 211 is provided with a sampling port, the sampling tube 212 is sleeved inside the outer tube 213, and one end of the sampling tube 212 close to the sampling drill bit 211 is open; the vibration penetration mechanism further includes a pair of eccentric wheels 322 installed on the output shafts of the vibration motors 321. As a schematic embodiment, the vibration penetration mechanism includes a pair of vibration motors 321. The pair of vibration motors 321 rotate synchronously in the forward and reverse directions respectively, and drive 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 and cancel each other out; in the vertical direction, they are equal in magnitude and the same in direction and are superimposed on each other to generate a downward thrust; thereby driving the sampling probe rod to move vertically downward. The sampling probe rod carries the receiving transducer 8 and penetrates into the seabed sediment, and at the same time samples the seabed sediment.

[0054] In some embodiments, as Figure 7 shown, a geological drill bit 221 is provided at the end of the geological probe rod, a sleeve 222 is provided on the outer periphery of the geological probe rod, and a flushing gap is provided between the geological probe rod and the sleeve 222; the water jet drilling mechanism is installed at one 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 water 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.

[0055] Further, as Figure 7 shown, flushing gaps are provided both 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 one end of the sleeve 222 away from the geological drill bit 221, and the water outlet of the high-pressure water pump 312 is connected to the opening of the sleeve 222. When the water jet drilling mechanism works, the rotary motor 311 drives the geological probe rod to move vertically downward. The geological probe rod carries the receiving transducer and penetrates 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, Figure 7 where the dotted line in it indicates the water flow direction. The water flows into the high-pressure water pump 312 through the water inlet, flows from the water outlet to the opening of the sleeve 222, and penetrates through the flushing gap to wash the seabed sediment adhering to the geological probe rod.

[0056] In the above technical solution, the in-situ measurement system for low-frequency acoustic characteristics of seabed sediments can select appropriate probe rods 2 and penetration mechanisms 3 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.

[0057] In some embodiments, as Figure 2 shown, the in-situ measurement system for low-frequency acoustic characteristics of seabed sediments further includes a traction mechanism 4. The traction mechanism 4 is fixedly installed in the main frame 1. The traction mechanism 4 includes a traction rope 402. One end of the traction rope 402 is connected to the probe rod 2 for towing or lifting the probe rod 2. Through the setting of the traction mechanism 4, the operation of the probe rod 2 is made more convenient, and the lifting of the probe rod 2 can be easily achieved.

[0058] In some embodiments, as Figure 5 shown, the traction mechanism 4 further includes a winch 401. The winch 401 is fixedly connected to the main frame 1. The other end of the traction rope 402 is wound around the winch 401. The winch 401 is used for taking in and paying out the traction rope 402. Through the setting of the winch 401, the taking in and paying out of the traction rope 402 is made more efficient, facilitating the operation and management of the measurement system.

[0059] In some embodiments, as Figure 5 shown, the traction mechanism 4 further includes a guide pulley 403. The guide pulley 403 is fixed to the upper part of the main frame 1. One end of the traction rope 402 bypasses the guide pulley 403 and is connected to the probe rod 2. Through the setting of the guide pulley 403, the traction work is made more labor-saving, and at the same time, it ensures that the movement track of the traction rope 402 is more accurate.

[0060] Furthermore, as Figure 5 shown, the traction mechanism 4 further includes a cylinder 404 that provides power for the winch 401. The cylinder 404 is connected to the winch 401. Through the setting of the cylinder 404, reliable power support is provided for the winch 401 to ensure the smooth progress of the taking in and paying out process of the traction rope 402.

[0061] In some embodiments, as Figure 5 shown, the traction mechanism 4 further includes a fixed bracket 405. The fixed bracket 405 includes being fixed in the main frame 1 and fixedly connected to the cylinder 404 and the winch 401 respectively. Through the setting of the fixed bracket 405, it is ensured that the various components of the traction mechanism 4 are firmly connected, improving the overall stability and reliability of the system.

[0062] In some embodiments, as Figure 4As shown in the figure, the main frame 1 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 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 penetration mechanism 3 is detachably connected to the column 101 and slidably connected to the column 101. By arranging the column 101 in the main frame 1 and making the penetration mechanism 3 detachably and slidably connected to the column 101, the stability and flexibility of the structure are achieved, which is convenient for installation and disassembly, and improves the adaptability and operation convenience of the measurement system.

[0063] In some embodiments, as Figure 4 shown, to improve the stability of the lifting and lowering of the probe rod 2 and the penetration mechanism 3, two columns 101 are provided. By arranging two columns 101, the support points of the system are increased, making the probe rod 2 and the penetration mechanism 3 more stable during the lifting and lowering process, reducing the possibility of shaking and offset, and thus improving the measurement accuracy.

[0064] Furthermore, as Figure 1 shown, a detachable sliding connection member 301 is provided at the connection between the penetration mechanism 3 and the column 101. The sliding connection member 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 connection member 301. Through the setting of the sliding connection member 301, the penetration mechanism 3 can be conveniently disassembled and installed, improving the flexibility of the system and the convenience of maintenance, and at the same time ensuring the stability of the penetration mechanism 3 during use.

[0065] In some embodiments, as Figure 4 shown, a load-bearing head 11 is provided above the upper end face of the main frame 1. The load-bearing head 11 is used to connect the cable of the survey ship. Specifically, a winch for taking in and paying out the cable is provided on the survey ship, and the survey personnel take in and pay out the cable to retrieve or lower the in-situ measurement system for the low-frequency acoustic characteristics of submarine sediments.

[0066] In some embodiments, as Figure 1 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 observe whether the in-situ measurement system is approaching the seabed. When approaching the seabed, the survey personnel slow down the lowering speed in advance to avoid device damage. The camera 10 can also be used for the entire measurement process such as the penetration process of the probe rod 2 and the retrieval process of the probe rod 2.

[0067] In some embodiments, as Figure 4As shown in the figure, a limiting plate 102 for defining the position of the sounding rod 2 is provided on the lower end surface of the main body frame 1. By providing the limiting plate 102, the position of the sounding rod 2 is effectively defined, preventing the sounding rod 2 from shifting during the penetration process, ensuring that the sounding rod 2 always remains on the predetermined track, and improving the measurement accuracy and reliability.

[0068] In some embodiments, the in-situ measurement system for the low-frequency acoustic characteristics of submarine sediments further includes a host computer, which is communicatively connected to the control cabin. The host computer is used to preset and send the acoustic signal parameters emitted by the transmitting transducer 6. The acoustic signal parameters include waveform type, frequency, number of cycles, amplitude, etc., and perform channel selection for the transmitting transducer 6.

[0069] Furthermore, as Figure 3 shown in the figure, the control cabin includes a transmitting control cabin 5 and a receiving control cabin 7, and the transmitting control cabin 5 is communicatively connected to the receiving control cabin 7. Among them, the transmitting control cabin 5 is used to control a plurality of transmitting transducers 6 and emit acoustic signals according to the parameters preset by the host computer; at the same time, the transmitting control cabin 5 is also communicatively connected to the swing arm mechanism 9 and is used to receive the instruction from the host computer to open the swing arm mechanism 9 and control the first connecting rod 903 to rotate and open. The receiving control cabin 7 is used to control a plurality of receiving transducers 8. The receiving control cabin 7 is communicatively connected to the penetration mechanism 3 and is used to receive the penetration instruction from the host computer and control the penetration mechanism 3 to start, so as to drive the sounding rod 2 to penetrate into the submarine sediments. The receiving control cabin 7 is also communicatively connected to the traction mechanism 4 and is used to receive the retraction instruction from the host computer and control the traction mechanism 4 to work, so as to lift the sounding rod 2 out of the submarine sediments for retraction.

[0070] In some embodiments, as Figure 3 shown in the figure, a power supply 12 is installed on the lower end surface of the main body 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 for supplying power to the in-situ measurement system for the low-frequency acoustic characteristics of submarine sediments.

[0071] Based on the above in-situ measurement system for the low-frequency acoustic characteristics of submarine sediments, the usage method of the system will be described below. The in-situ measurement method for the low-frequency acoustic characteristics of submarine sediments includes the following steps:

[0072] S1, according to the characteristics of the submarine sediments in the detection sea area, select the corresponding sounding rod 2 and penetration mechanism 3, and install the in-situ measurement system;

[0073] In this step, the probe rod 2 is connected to the penetration mechanism 3. After the sliding connector 301 is connected to the penetration mechanism 3, the sliding connector 301 is fixed to the column 101 of the main frame 1. The probe rod 2 and the penetration mechanism 3 are mainly selected according to the hardness, density, etc. of the seabed sediment. For seabed sediments with larger particles, high hardness and relatively loose, such as silty sand, a geological probe rod and a water jet drilling mechanism are selected for installation; for seabed sediments with smaller particles, high density and low hardness, such as sandy silt, a sampling probe rod and a vibration penetration mechanism are selected for installation.

[0074] 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.

[0075] In this step, the surveyor lowers the in-situ measurement system by lowering the cable connected to the ship's winch, and at the same time monitors the lowering height of the in-situ measurement system by using the camera 10. When the in-situ measurement system approaches the seabed, the lowering speed is slowed down. The process of the swing arm mechanism 9 rotating the first connecting rod 903 to the horizontal direction includes: the power key of the swing arm mechanism 9 provides rotational power for the rotating shaft, and the rotating shaft carries the slide rail 906 and the first connecting rod 903 to rotate until the first connecting rod 903 rotates to the horizontal direction. After that, the first connecting rod 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, the pressure sensor 905 is used to assist in detecting the pressure received by the transmitting transducer 6 until the transmitting transducer 6 is in good contact with the seabed sediment, and at the same time, to prevent the transmitting transducer 6 from being damaged due to excessive pressure.

[0076] S3. Use the penetration mechanism 3 to drive the probe rod 2 to penetrate into the seabed sediment to a preset depth.

[0077] In this step, when the penetration mechanism 3 adopts a vibration penetration mechanism, the vibration motor 321 of the penetration mechanism 3 drives the sampling probe rod to move vertically downward. The sampling probe rod carries the receiving transducer 8 to penetrate into the seabed sediment and at the same time samples the seabed sediment; when the penetration mechanism 3 adopts a water jet drilling mechanism, the rotating motor 311 drives the geological probe rod to move vertically downward. The geological probe rod carries the receiving transducer to penetrate into the seabed sediment, and 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 adhered to the geological probe rod.

[0078] S4. The control cabin controls the transmitting transducer 6 to emit acoustic signals with preset parameters, and controls the receiving transducer 8 to receive the acoustic signals, and at the same time records the emitted and received acoustic signals respectively.

[0079] In this step, the host computer presets the parameters of the acoustic wave signal and selects the channels of the transmitting transducers 6. Multiple transmitting transducers 6 or one of the transmitting transducers 6 can be selected simultaneously. After the host computer sends an instruction to the transmitting control cabin 5, the transmitting control cabin 5 controls the transmitting transducers 6 to emit acoustic wave signals with preset parameters; the receiving control cabin 7 controls the receiving transducers 8 to work. At this time, the probe rod 2 and the first connecting rod 903 are in a vertical state, and the receiving transducers 8 and the transmitting transducers 6 installed on the probe rod 2 and the first connecting rod 903 meet the conditions for oblique measurement.

[0080] S5. Repeat steps S3 - S4 to obtain the acoustic characteristics of acoustic wave signals with different parameters in the seabed sediments at different depths;

[0081] In this step, the calculation method of the acoustic characteristics is as follows: Denote that the transmitting transducer 6 emits an acoustic wave signal with a certain frequency (f) and an amplitude of A1 at time T1. The time for the acoustic wave signal to reach the receiving transducer 8 is T2, and the amplitude is A2. The sound velocity V of the acoustic wave signal in the sediment can be calculated according to Equation (1), and the sound attenuation coefficient α of the acoustic wave in the sediment can be calculated using Equation (2); the expression of Equation (1) is:

[0082]

[0083] The expression of Equation (2) is:

[0084]

[0085] S6. Lift the in-situ measurement system upward to a certain distance away from the seabed;

[0086] In this step, lift the in-situ measurement system upward to 5 m away from the seabed.

[0087] S7. Repeat step S4 to obtain the acoustic characteristics of acoustic wave signals with different parameters in the water body at different depths.

[0088] In the above-mentioned schematic embodiments, by first measuring the acoustic characteristics of the seabed sediments and then lifting the in-situ measurement system to measure the acoustic characteristics of the water body near the seabed sediments, it is possible to provide more sufficient data support for calibrating and interpreting the acoustic characteristic data of the seabed sediments, and improve the accuracy and reliability of the measurement.

[0089] In some embodiments, step S2 further includes that 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 sediments.

[0090] In some embodiments, step S6 further includes using the towing rope 402 to lift the sounding rod 2 upward to lift the sounding rod 2 out of the seabed sediment; in step S7, before repeating step S4, the penetration mechanism 3 is used to drive the sounding rod 2 to descend to a preset depth. The step of using the towing rope 402 to lift the sounding rod 2 upward includes: using the cylinder 404 to drive the winch 401 to rotate, and the towing rope 402 passes through the guiding pulley 403 to lift the penetration mechanism 3 upward, thereby lifting the sounding rod 2. It should be noted that during the process of the sounding rod 2 penetrating into the seabed sediment, the towing rope 402 is stretched by the action of the penetration mechanism 3.

[0091] In some embodiments, in step S6, the in-situ measurement system is lifted upward by 5 m from the seabed. By lifting the in-situ measurement system upward by 5 m, when the sounding rod 2 descends, the bottom of the sounding rod 2 is 2 m away from the seabed, and the acoustic characteristics of the water body near the seabed sediment can be effectively measured.

[0092] In some embodiments, the in-situ measurement method for the low-frequency acoustic characteristics in seabed sediment further includes: S8, analyzing and comparing the sound velocity and sound attenuation coefficient of the acoustic wave signal in the seabed sediment and the water body.

[0093] Through the description of multiple embodiments of the in-situ measurement system for the low-frequency acoustic characteristics in seabed sediment of the present invention, it can be seen that the embodiments of the in-situ measurement system for the low-frequency acoustic characteristics in seabed sediment of the present invention have at least one or more of the following advantages:

[0094] 1. The in-situ measurement system for the low-frequency acoustic characteristics in seabed sediment provided by the present invention can simultaneously measure the acoustic characteristics of acoustic waves with multiple frequencies in the seabed sediment, reducing the time and cost of multiple measurements and improving the measurement efficiency; and through the collaborative work of multiple receiving transducers 8 and transmitting transducers 6, more accurate and comprehensive acoustic characteristic data can be obtained, improving the reliability of the measurement results;

[0095] 2. The in-situ measurement system for the low-frequency acoustic characteristics in seabed sediment provided by the present invention can select appropriate sounding rods 2 and penetration mechanisms 3 according to different types of seabed sediment, 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;

[0096] 3. The in-situ measurement system for the low-frequency acoustic characteristics in seabed sediment provided by the present invention, through the setting of the pressure sensor 905, monitors the pressure received by the transmitting transducer 6 in real time, ensures good contact between the transmitting transducer 6 and the seabed sediment, and ensures that the entire propagation process of the acoustic wave signal is completed in the seabed sediment, thereby effectively reducing the measurement error.

[0097] Finally, it should be noted that the embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0098] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present invention or make equivalent replacements for some technical features. Without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. An in-situ measurement system for low-frequency acoustic properties in submarine sediments, characterized in that, Including: Main body frame; Probe rod, which is installed inside the main body frame. The probe rod is slidably connected to the main body frame and can vertically lift relative to the main body frame for penetrating into the seabed sediments. Multiple receiving transducers capable of receiving medium and low frequency acoustic waves are installed at one end of the probe rod close to the seabed sediments; Swing arm mechanism, which is fixedly connected to the main body frame. The swing arm mechanism is provided with a rotatable first connecting rod. Multiple transmitting transducers are installed on the first connecting rod. The multiple transmitting transducers include medium frequency transmitting transducers and low frequency transmitting transducers. When performing measurement work, the first connecting rod rotates to the horizontal direction perpendicular to the probe rod; Control cabin, which is fixedly connected to the main body frame and is respectively communicatively connected to multiple receiving transducers and multiple transmitting transducers for controlling the multiple receiving transducers and multiple transmitting transducers.

2. The in-situ measurement system for low-frequency acoustic characteristics in submarine sediments according to claim 1, wherein The swing arm mechanism further includes a rotating member and a slide rail. The slide rail is fixedly connected to the rotating member and rotates with the rotating member. The first connecting rod is vertically slidably connected to the slide rail and rotates with the rotating member and the slide rail; when the first connecting rod rotates to the horizontal direction perpendicular to the probe rod, the first connecting rod vertically slides along the slide rail to adjust the relative height between the transmitting transducer and the seabed sediments.

3. The in-situ measurement system for low-frequency acoustic characteristics in submarine sediments according to claim 2, characterized in that, The swing arm mechanism further includes a second connecting rod, which is connected to the end of the first connecting rod away from the slide rail; a pressure sensor is installed on the second connecting rod. When the first connecting rod rotates to the horizontal direction perpendicular to the probe rod, 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 received by the transmitting transducer to determine whether the relative height between the transmitting transducer and the seabed sediments is appropriate.

4. The in-situ measurement system for low-frequency acoustic characteristics in submarine sediments according to claim 1, characterized in that, The probe rod is detachably connected to the main body frame. The probe rod includes a sampling probe rod or a geological probe rod. When performing measurement work, the sampling probe rod or the geological probe rod is selected and installed according to the characteristics of the seabed sediments.

5. The in-situ measurement system for low-frequency acoustic characteristics in submarine sediments according to claim 4, characterized in that, It further includes a penetration mechanism, which is detachably connected to the inside of the main body frame. The penetration mechanism is slidably connected to the active frame and is connected to the probe rod for providing the power for the probe rod to penetrate into the seabed sediments; the penetration mechanism includes a vibration penetration mechanism or a water jet drilling mechanism. When the sampling probe rod is selected for measurement work, the vibration penetration mechanism is installed; when the geological probe rod is selected for measurement work, the water jet drilling mechanism is installed.

6. The in-situ measurement system for low-frequency acoustic characteristics in submarine sediments according to claim 5, wherein The sampling probe rod is hollow inside, and a sampling port is provided at the end of the sampling probe rod. When the sampling probe rod penetrates into the seabed sediments, part of the seabed sediments enter the inside of the sampling probe rod through the sampling port to complete sampling; the vibration penetration mechanism is installed at the end of the sampling probe rod away from the sampling bit. The vibration penetration mechanism includes at least a pair of vibration motors, and the vibration motors are used to drive the sampling probe rod to move vertically downward.

7. The in-situ measurement system for low-frequency acoustic characteristics in submarine sediments according to claim 5, characterized in that 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. There is a flushing gap 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 rotating motor and a high-pressure water pump. The water outlet of the high-pressure water pump is connected to the flushing gap. The rotating 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.

8. The in-situ measurement system for low-frequency acoustic characteristics in submarine sediments according to claim 1, characterized in that, It further includes a traction mechanism, which is fixedly installed inside the main body frame. The traction mechanism includes a traction rope, and one end of the traction rope is connected to the probe rod for towing or lifting the probe rod.

9. The in-situ measurement system for low-frequency acoustic characteristics in submarine sediments according to claim 8, characterized in that, The traction mechanism further includes a winch, which is fixedly connected to the main body frame. The other end of the traction rope is wound around the winch, and the winch is used to take in and pay out the traction rope.

10. The in-situ measurement system for low-frequency acoustic characteristics in submarine sediments according to claim 8, characterized in that, The traction mechanism further includes a guide pulley, which is fixed to the upper part of the main body frame. One end of the traction rope bypasses the guide pulley and is connected to the probe rod.

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