An acoustic in-situ sampling and measurement system for seafloor sediments

Abstract

The present invention discloses an acoustic in-situ sampling and measurement system for seabed sediments. The system comprises: a measuring device, a sampling device, a measurement control device and a supporting device; the supporting device is connected to a mother ship through a cable; the sampling device is arranged at the bottom of the supporting device, and the sampling device is used to obtain seabed sediment samples; the measuring device is arranged on the supporting device, and the measuring device is used to perform acoustic measurements; the measurement control device is arranged on the supporting device, and the measurement control device is electrically connected to the measuring device, and the measurement control device is used to control the measuring device to perform acoustic measurements. The seabed sediment acoustic in-situ sampling and measurement system of the present invention can realize in-situ measurement and synchronous sampling of the acoustic characteristics of seabed sediments by arranging the measuring device and the sampling device.

Description

Technical Field

[0001] The invention relates to the technical field of marine engineering exploration, and in particular to an acoustic in-situ sampling and measuring system for seabed sediments. Background Art

[0002] The acoustic characteristic parameters of seabed sediments have always been an important research topic in the fields of hydroacoustic communications, submarine and mine detection, and marine engineering exploration. The main research methods at present are in-situ measurements on the seabed and laboratory measurements after seabed sampling.

[0003] Existing research methods cannot provide accurate acoustic characteristic parameters of seafloor surface sediments. Several newly developed acoustic in-situ measurement systems can only accurately measure the acoustic characteristic parameters of seafloor sediments, and cannot simultaneously obtain seafloor bottom sediment samples. To obtain seafloor bottom sediment samples, it is necessary to go to the seafloor to take samples, which cannot guarantee that the acoustic parameters obtained by in-situ measurement correspond to the same sample as the seafloor bottom sample. Currently, there is no equipment that can perform sediment sampling while measuring the acoustic parameters of the seafloor surface sediment in situ. This situation prevents the comparative analysis of the sampling measurement data of the acoustic properties of seafloor sediments and the in-situ measurement data, and severely limits the in-depth study of the relationship between the acoustic properties of seafloor surface sediments and their physical properties. In order to overcome this situation, it is necessary to develop relevant seafloor acoustic in-situ measurement and sampling equipment. Summary of the invention

[0004] The purpose of the present invention is to provide a seabed sediment acoustic in-situ sampling and measurement system, which can realize in-situ measurement of the acoustic characteristics of seabed sediments and synchronous sampling.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A seabed sediment acoustic in-situ sampling and measurement system, comprising:

[0007] Measuring devices, sampling devices, measurement control devices and support devices;

[0008] The supporting device is connected to the mother ship via cables;

[0009] The sampling device is arranged at the bottom of the supporting device, and the sampling device is used to obtain seabed sediment samples;

[0010] The measuring device is arranged on the supporting device, and the measuring device is used for performing acoustic measurement;

[0011] The measurement control device is arranged on the supporting device, the measurement control device is electrically connected to the measuring device, and the measurement control device is used to control the measuring device to perform acoustic measurement.

[0012] Optionally, the system further includes:

[0013] Water main control system;

[0014] The above-water main control system is connected to the measuring device and the measuring control device respectively, and the above-water main control system is used to issue control instructions and obtain underwater measuring data.

[0015] Optionally, the measuring device specifically comprises:

[0016] Acoustic module, acceleration measurement module and ranging module;

[0017] The acoustic module, the acceleration measurement module and the distance measurement module are all connected to the measurement control device;

[0018] The acoustic module is used to measure the acoustic characteristics of seabed sediments;

[0019] The acceleration measurement module is used to identify positive and negative changes in acceleration;

[0020] The distance measuring module is used to measure the height from the seabed;

[0021] The measurement control device is used to control the acoustic module to measure the acoustic characteristics of seabed sediments when the acceleration measurement module identifies that the acceleration changes from positive to negative; the measurement control device is also used to store the height information from the seabed transmitted by the ranging module.

[0022] Optional,

[0023] The acoustic module specifically includes:

[0024] a transmitting transducer and a receiving transducer;

[0025] The transmitting transducer is arranged on the supporting device, and the receiving transducer is arranged on the sampling device;

[0026] The acceleration measurement module specifically includes:

[0027] Accelerometers and acceleration measurement circuits;

[0028] The acceleration measurement circuit is connected to the accelerometer and the measurement control device respectively; the acceleration measurement circuit is used to identify positive and negative changes in acceleration.

[0029] Optionally, the measuring device further includes:

[0030] Inclinometer;

[0031] The inclinometer is arranged on the supporting device and is connected to the measuring control device; the inclinometer is used to monitor whether the sampling device is vertically inserted into the seabed.

[0032] Optionally, the sampling device specifically comprises:

[0033] Sampling outer tube, sampling inner tube, sampling liner, sampling head and non-return spring plate;

[0034] The sampling inner tube is sleeved on the sampling liner, and the sampling outer tube is sleeved on the sampling inner tube;

[0035] The sampling head is arranged at the bottom of the sampling outer tube, and the top of the sampling outer tube is arranged at the bottom of the supporting device;

[0036] The anti-return spring sheet is arranged inside the sampling head, and the sediment enters the sampling liner through the sampling head. The anti-return spring sheet is used to prevent the sediment entering the sampling liner from falling off;

[0037] A plurality of blocking grooves are provided on the outer wall of the sampling outer tube, and the receiving transducer is arranged in the blocking grooves.

[0038] Optionally, the supporting device specifically comprises:

[0039] Load-bearing brackets and mounting bases;

[0040] The load-bearing bracket is arranged on the carrying base, and the top of the load-bearing bracket is connected to the mother ship through a cable; the measuring device and the measuring control device are both arranged on the upper surface of the carrying base, and the sampling device is arranged on the lower surface of the carrying base.

[0041] Optionally, the acoustic module further includes:

[0042] A first wave absorbing silica gel and a second wave absorbing silica gel;

[0043] The first wave-absorbing silica gel is connected to the transmitting transducer, and the first wave-absorbing silica gel is used to prevent the sound waves from being transmitted from the transmitting transducer to the receiving transducer along the sampling outer tube;

[0044] The second wave-absorbing silica gel is arranged between the blocking groove and the receiving transducer, and the second wave-absorbing silica gel is used to enable the receiving transducer to only receive the sound waves transmitted by the transmitting transducer through the seabed sediments.

[0045] Optionally, the system further includes:

[0046] Lead weights;

[0047] The weighted lead block is arranged on the upper surface of the carrying base, and the weighted lead block is used to make the sampling device insert into the seabed sediment to reach a preset depth.

[0048] Optionally, the system further includes:

[0049] Underwater circuit sealed cabin;

[0050] The underwater circuit sealed cabin is arranged on the supporting device, and the measurement control device, the accelerometer, the acceleration measurement circuit and the inclinometer are all arranged in the underwater circuit sealed cabin.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] The present invention proposes an acoustic in-situ sampling and measurement system for seabed sediments, comprising a measuring device, a sampling device, a measuring control device and a supporting device; the supporting device is connected to a mother ship through a cable; the sampling device is arranged at the bottom of the supporting device, and the sampling device is used to obtain seabed sediment samples; the measuring device is arranged on the supporting device, and the measuring device is used to perform acoustic measurement; the measuring control device is arranged on the supporting device, and the measuring control device is electrically connected to the measuring device, and the measuring control device is used to control the measuring device to perform acoustic measurement. The present invention can realize in-situ measurement of acoustic characteristics of seabed sediments and synchronous sampling by arranging the measuring device and the sampling device. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0054] Figure 1 This is a structural diagram of an acoustic in-situ sampling and measurement system for seabed sediments in an embodiment of the present invention;

[0055] Figure 2 It is a schematic diagram of the structure of a sampling device in an embodiment of the present invention;

[0056] Figure 3 This is a schematic diagram of system control in an embodiment of the present invention;

[0057] Figure 4 Schematic diagram of the sound wave transmission path in an embodiment of the present invention.

[0058] Explanation of reference numerals: 1-sampling head; 2-sampling outer tube; 3-carrying base; 4-distance measuring transducer; 5-weighted lead block; 6-load-bearing bracket; 7-armored cable; 8-underwater circuit sealing cabin; 9-acceleration measurement module; 10-measurement control device; 11-first wave-absorbing silica gel; 12-transmitting transducer; 13-sampling inner tube; 14-sampling liner; 15-barrier groove; 16-receiving transducer; 17-second wave-absorbing silica gel; 18-anti-return spring. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] The purpose of the present invention is to provide a seabed sediment acoustic in-situ sampling and measurement system, which can realize in-situ measurement of the acoustic characteristics of seabed sediments and synchronous sampling.

[0061] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0062] Example

[0063] like Figure 1-4 As shown, a seabed sediment acoustic in-situ sampling and measurement system includes: a measuring device, a sampling device, a measurement control device 10, a supporting device and an above-water main control system. The supporting device is connected to a mother ship through a cable (armored cable 7); the sampling device is arranged at the bottom of the supporting device, and the sampling device is used to obtain seabed sediment samples; the measuring device is arranged on the supporting device, and the measuring device is used to perform acoustic measurement; the measurement control device is arranged on the supporting device, and the measurement control device is electrically connected to the measuring device, and the measurement control device is used to control the measuring device to perform acoustic measurement; the above-water main control system is connected to the measuring device and the measurement control device respectively, and the above-water main control system is used to issue control instructions and obtain underwater measurement data.

[0064] The supporting device specifically includes: a load-bearing bracket 6 and a carrying base 3. The load-bearing bracket is arranged on the carrying base, and the top of the load-bearing bracket is connected to the mother ship through a cable; the measuring device and the measuring control device are both arranged on the upper surface of the carrying base, and the sampling device is arranged on the lower surface of the carrying base.

[0065] The measuring device specifically includes: an acoustic module, an acceleration measurement module 9, a ranging module and an inclinometer (not shown in the figure). The acoustic module, the acceleration measurement module and the ranging module are all connected to the measurement control device; the acoustic module is used to measure the acoustic characteristics of the seabed sediments; the acceleration measurement module is used to identify the positive and negative changes in acceleration; the ranging module is used to measure the height from the seabed. The ranging module is a ranging transducer 4. The measurement control device is used to control the acoustic module to measure the acoustic characteristics of the seabed sediments when the acceleration measurement module identifies that the acceleration changes from positive to negative; the measurement control device is also used to store the height information from the seabed transmitted by the ranging module. The inclinometer is arranged on the supporting device, and the inclinometer is connected to the measurement control device; the inclinometer is used to monitor whether the sampling device is vertically inserted into the seabed substrate.

[0066] The acoustic module specifically includes: a transmitting transducer 12, a receiving transducer 16, a first absorbing silica gel 11 and a second absorbing silica gel 17; the transmitting transducer is arranged on a supporting device, and the receiving transducer is arranged on a sampling device. The first absorbing silica gel is connected to the transmitting transducer, and the first absorbing silica gel is used to prevent the sound waves from being transmitted from the transmitting transducer to the receiving transducer along the sampling outer tube; the second absorbing silica gel is arranged between the blocking groove and the receiving transducer, and the second absorbing silica gel is used to make the receiving transducer only receive the sound waves transmitted by the transmitting transducer through the seabed sediment.

[0067] The acceleration measurement module specifically comprises: an accelerometer and an acceleration measurement circuit; the acceleration measurement circuit is connected to the accelerometer and the measurement control device respectively; the acceleration measurement circuit is used to identify positive and negative changes in acceleration.

[0068] The sampling device specifically comprises: a sampling outer tube 2, a sampling inner tube 13, a sampling liner 14, a sampling head 1 and a non-return spring sheet 18. The sampling inner tube is sleeved on the sampling liner, and the sampling outer tube is sleeved on the sampling inner tube; the sampling head is arranged at the bottom of the sampling outer tube, and the top of the sampling outer tube is arranged at the bottom of the supporting device; the non-return spring sheet is arranged inside the sampling head, and the sediment enters the sampling liner through the sampling head, and the non-return spring sheet is used to prevent the sediment entering the sampling liner from falling off; a plurality of blocking grooves 15 are opened on the outer wall of the sampling outer tube, and the receiving transducer is arranged in the blocking grooves.

[0069] The acoustic in-situ sampling and measurement system for seabed sediments also includes: a weighted lead block 5 and an underwater circuit sealed cabin 8. The weighted lead block is arranged on the upper surface of the carrying base, and the weighted lead block is used to make the sampling device insert into the seabed sediment to a preset depth. The underwater circuit sealed cabin is arranged on the supporting device, and the measurement control device, the accelerometer, the acceleration measurement circuit and the inclinometer are all arranged in the underwater circuit sealed cabin.

[0070] The water main control system includes an industrial computer, a USB interface, a GPS positioning unit, an above-water data transmission interface, and a power supply unit. The above-water main control system is installed on the deck of the mother ship. When performing operations such as command setting and data export on the water, the data transmission interface of the above-water main control system is connected to the subsea data transmission interface of the subsea control system through a signal cable, and control instructions are sent to the subsea control system to obtain subsea measurement data; the USB interface and the above-water transmission interface of the above-water main control system are welded in the industrial computer, the power supply unit is connected to the industrial computer through a cable, and the GPS receiving antenna is connected to the GPS unit in the industrial computer through a signal cable.

[0071] The measurement and control device includes a submarine transmission interface, a digital signal processor, a TF card, a high-speed AD, a receiving amplifier circuit, a transmitting control circuit and an FPGA control chip. The various components of the measurement and control device are welded on a circuit board, wherein the submarine transmission interface is connected to the digital signal processor, the digital signal processor is connected to the FPGA control chip, the TF card is connected to the FPGA control chip, the receiving transducer is connected to the receiving amplifier circuit, the receiving amplifier circuit is connected to the FPGA control chip and the high-speed AD, the high-speed AD is connected to the FPGA control chip, the transmitting transducer is connected to the transmitting control circuit, the transmitting control circuit is connected to the FPGA control chip, the lithium battery is connected to the high and low voltage power supply, the high and low voltage power supply is connected to the transmitting control circuit and the FPGA control chip, the accelerometer is connected to the acceleration measurement circuit, and the acceleration measurement circuit is connected to the FPGA control chip.

[0072] The present invention provides a seabed sediment acoustic in-situ sampling and measurement system, which is used to realize in-situ measurement and synchronous sampling of acoustic characteristics of seabed sediments. The water main control system is installed on the deck of the mother ship, and is connected to the measurement control device, the acoustic module, and the acceleration measurement module through the signal cable USB interface, the water data transmission interface, and the seabed data transmission interface to obtain the data of the seabed control system (including the underwater circuit sealed cabin, the seabed data transmission interface, the measurement control device, and the power module), and send control instructions to the seabed control system.

[0073] The sampling device and seabed control system are connected to the mother ship through steel cables. The seabed data transmission interface, measurement control device, acceleration measurement module, and power supply module are all integrated in the underwater circuit sealed cabin. The sensor system (ranging transducer, inclinometer) is carried on the sampling device.

[0074] The receiving transducer is connected to the second wave-absorbing silica gel, the second wave-absorbing silica gel is connected to the sampling outer tube, the sampling outer tube is connected to the carrying base, the sampling outer tube is processed with a blocking groove, the carrying base is connected to the load-bearing bracket, the load-bearing bracket is connected to the armored cable, the underwater circuit sealed cabin is connected to the carrying base, the inclinometer and the accelerometer are in the underwater circuit sealed cabin, the ranging transducer is connected to the carrying base, the transmitting transducer is connected to the first wave-absorbing silica gel, and the first wave-absorbing silica gel is connected to the carrying base. The sampling inner tube is connected to the carrying base and the sampling liner, the sampling liner is connected to the sampling inner tube and the carrying base, the sampling head is connected to the sampling outer tube, the sampling inner tube and the sampling liner, and the non-return spring is fixed in the sampling head.

[0075] The power module is connected to the seabed control system through a cable to supply power to the seabed control system. The seabed transmission interface is connected to the measurement control device, which is connected to the acoustic module. The accelerometer is connected to the acceleration measurement circuit, which is connected to the measurement control device.

[0076] The seabed sediment acoustic in-situ sampling and measurement system provided by the present invention can obtain seabed sediment samples, and the length of the sediment sample that can be obtained by the sampling device is not less than 1.5m. While obtaining the sediment sample, the sound velocity and acoustic attenuation coefficient of the sediment can be measured in situ. It has a universal USB interface, which can be conveniently used for command setting with each host computer and exchange data with each host computer. It has a bottom ranging function and can measure the distance between the system and the seabed. It can work at a water depth of less than 3000m, and its underwater circuit sealed cabin, transmitting transducer, and receiving transducer can withstand the pressure of a water depth of 3000m. Acoustic characteristics There is one transmitting transducer and eight receiving transducers. The eight receiving transducers are arranged vertically at a certain interval and are embedded in the outer wall of the sampling tube in a ring shape. The underwater unit is powered by the system's own battery. At this time, the collected data is stored in the system's built-in memory, and the sampling measurement and other actions are automatically controlled by the setting program. The weighted lead block can be adjusted according to the needs to adjust the overall weight of the sampling and measurement system. The obtained sediment samples are stored in the sampling liner, and there is a sampling inner tube outside the sampling liner, which provides protection for the sampling liner. A sampling head is fixed under the sampling liner, and a non-return spring is installed in the sampling head. The non-return spring allows the sediment sample to enter the sampling liner smoothly without falling out. An inclinometer is installed on the top to monitor whether the system is vertically inserted into the seabed. The system starts instantly when the instrument touches the bottom. The acceleration measurement device starts instantly when the instrument touches the bottom, so that the sampling measurement system can start the acoustic characteristic measurement within 2 seconds after the system touches the bottom. A ranging transducer is installed to monitor the insertion depth of the in-situ measurement system. A barrier groove is machined on the sampling outer tube of the system to prevent sound waves from propagating along the sampling outer tube. A first wave-absorbing silica gel is set between the transmitting transducer and the mounting base, and a second wave-absorbing silica gel is set between the receiving transducer and the sampling outer tube to prevent sound waves from propagating along the sampling outer tube.

[0077] In order to improve the measurement accuracy, the average sound speed measurement is used as the measured sound speed. The sound speed is calculated by the difference in the transmission time of the sound wave to different receivers and the distance difference between the transmitting transducer and different receivers:

[0078] V s =dL / dt

[0079] Where: V s is the speed of sound; dL is the distance difference between receivers; dt is the transmission time difference between different receivers.

[0080] During underwater operation, the sampling device is connected to the mother ship via a steel cable. The load-bearing bracket of the sampling device is fixedly connected to the steel cable via a U-shaped ring; the carrying base 3 is connected to the load-bearing bracket 6 by welding.

[0081] The seabed control system is integrated in the underwater circuit sealed cabin 8 of the sampling device; the underwater circuit sealed cabin 8 is connected to the carrying base 3 of the sampling device by bolts; the seabed data transmission interface, power module, measurement control device 10, and acceleration measurement module 9 are all integrated in the underwater circuit sealed cabin 8; the seabed transmission interface is connected to the measurement control device 10 through a signal cable; the power module is sealed in the underwater circuit sealed cabin 8, and is connected to the measurement control device through a cable to supply power to the seabed control system; the acoustic module is connected to the measurement control device 10 through a signal cable; the sensor system is connected to the measurement control device 10 through a signal cable.

[0082] The lithium battery of the power module is fixed in the underwater circuit sealing cabin 8, and the high and low voltage power supply units are connected to the lithium battery through cables.

[0083] The transmitting transducer 12 is connected to the measurement and control device interface of the underwater circuit sealed cabin 8 through a signal cable; the receiving transducer 16 is connected to the measurement and control device interface of the underwater circuit sealed cabin 8 through a signal cable; the transmitting transducer 12 is connected to the first wave-absorbing silicone rubber 11 through bolts, and the first wave-absorbing silicone rubber 11 is fixed to the carrying base 3 through bolts; the receiving transducer 16 is connected to the second wave-absorbing silicone rubber 17 through bolts, and is connected to the sampling outer tube 2 through the bolts, the second wave-absorbing silicone rubber 17 is pasted on the sampling outer tube 2, the sampling outer tube 2 is connected to the carrying base 3 through bolts, and a barrier groove 15 is processed on the sampling outer tube 2.

[0084] The inclinometer and accelerometer 9 are sealed in an underwater circuit sealed cabin 8, and the ranging transducer 4 is fixed to the carrying base 3 by bolts; the ranging transducer 4 is connected to the measurement control device 10 through a signal cable, the accelerometer is connected to the acceleration measurement circuit 9 through a signal cable, and the acceleration measurement circuit 9 is connected to the measurement control device 10 through a signal cable.

[0085] The seabed sediment acoustic in-situ sampling and measurement system of the present invention can simultaneously obtain columnar samples of seabed sediment while performing seabed acoustic in-situ measurement. During operation, the main control system on the water is mainly used to perform command control and parameter setting on the sampling and measurement system, and to export underwater collected data; the sampling device is mainly used to collect seabed sediment samples; the sensor system mainly uses acceleration sensors to collect the acceleration changes of the equipment during the lowering process, uses distance sensors to measure the height of the equipment from the seabed, and transmits the collected data to the seabed control system; the seabed control system mainly receives the data collected by the sensor system, and is used to drive the measurement control device to start working, so as to realize the acoustic in-situ measurement operation of seabed sediments.

[0086] The whole system adopts a self-contained operation mode, and the whole workflow is as follows:

[0087] 1. Before the system is launched into the water, the sampling device is assembled. The acquisition of sediment samples is mainly completed by weighted lead blocks, sampling inner tubes, sampling liners, sampling heads, and non-return springs; the lengths of the sampling inner tubes and sampling liners are both more than 1.5m, so as to obtain sediment samples with a length of not less than 1.5m; the sediment samples are stored in the sampling liners, which are made of plexiglass. The upper end of the sampling liners is positioned by the carrying base, and the lower end of the sampling liners is positioned by the sampling head. The outer diameter of the sampling liners is the same as the inner diameter of the sampling inner tube. The sampling liners are inside the sampling inner tube. When the sampling head is connected to the sampling inner tube through threads, the sampling liners 14 is fixed between the sampling inner tube 13, the sampling head 1, and the carrying base 3. The sampling inner tube 13 provides structural strength support for the sampling liner 14. When the sampling measurement system is quickly inserted into the sediment, the sampling liner will not be deformed or damaged. A non-return spring piece 18 is installed inside the sampling head 1. The non-return spring piece 18 is installed in the sampling head 1 at a certain angle. Multiple non-return spring pieces 18 form a conical head inside the sampling head. The conical head structure and the elasticity of the non-return spring piece allow the sediment to enter the sampling liner upward without escaping from the sampling liner.

[0088] 2. Install the lead weights: The lead weights 5 are fixed on the carrying base 3. The number of lead weights is increased or decreased according to the properties of the seabed sediments to ensure that the sampling device has enough weight to be quickly inserted into the sediment to a depth of 1.5 m.

[0089] 3. The measurement system uses its own battery to power the underwater unit. Before the system is launched into the water, the power module needs to be charged and the seabed control system needs to be commanded and set.

[0090] 4. The above-water main control system sets commands for the seabed control system; the USB interface of the above-water main control system is connected to the USB interface of the seabed control system by a signal cable, commands are set for the seabed control system, and the instrument is put into bottom-touching working mode; parameters of the acoustic measurement module are set through the seabed control system, and the acoustic wave excitation frequency, transmitting voltage, receiving gain, acquisition time, and sampling rate required for seabed acoustic measurement are set.

[0091] 5. Using the A-frame and cable winch on the ship, the sampling and measuring system is placed in the water and gradually approaches the seabed; an inclinometer is installed on the top of the system to monitor whether the system is vertically inserted into the seabed. The attitude parameters collected by the inclinometer are transmitted to the measurement control device, which performs A / D conversion and stores them in the TF card. After the measurement system is lifted to the deck, the data is exported for processing; a rangefinder transducer 4 is installed on the carrier bracket 3, which transmits sound signals to the seabed and then receives the reflected sound wave signals. According to the time of sound wave emission and reception, the height of the equipment from the seabed is accurately measured; when the sampling and measuring system is inserted into the sediment, the precise depth of the sampling tube inserted into the seabed can be determined according to the height of the equipment from the bottom measured by the rangefinder transducer and the total length of the sampling tube of the equipment. The height data collected by the rangefinder transducer from the bottom is transmitted to the measurement control device, which performs A / D conversion and stores them in the TF card. After the measurement system is lifted to the deck, the data is exported for processing.

[0092] 6. When the sampling and measuring system is close to the seabed, the sampling and measuring system is quickly lowered to be inserted into the sediment. After the measuring system reaches the seabed, the sampling tube is quickly inserted into the seabed substrate by using the deadweight of the lead block loaded by the sampling and measuring system. During the entire working process of the acoustic module, the inclinometer and the ranging transducer continuously collect attitude parameters and height from the bottom, and send them to the measurement control device through the seabed transmission interface. After high-speed A / D conversion, they are stored in the TF card of the measurement control device. The data will be exported after the equipment is out of water. After processing, it is determined whether the sampling tube penetrates vertically into the seabed, and the depth of the sampling tube penetrating into the seabed is calculated. The seabed sediment passes through the sampling head 1 and the non-return spring 18 and enters the sampling liner 14. After that, when the sampling device is lifted, the deadweight of the sediment will suppress the non-return spring to close, preventing the sediment sample from falling out of the sampler liner, that is, the sampling is successful.

[0093] 7. When the measuring system touches the bottom, the instrument's instantaneous start-up system starts working. The instrument's instantaneous start-up system includes an accelerometer and an acceleration acquisition module, so that the sampling measurement system can start the acoustic characteristic measurement within 2 seconds of the system touching the bottom; the acoustic module is in standby mode before starting, and enters the acquisition mode after touching the bottom, and re-enters the standby mode after the acquisition work is completed. This method effectively saves system power and is helpful in extending the service life of the lithium battery. The sampling measurement system only measures the acoustic characteristics for a very short period of time (within 2 seconds) after the sampling device is inserted into the sediment. Therefore, it is necessary to start the instrument at the moment of touching the bottom, and the acceleration measurement circuit measures the positive and negative value changes of the accelerometer. The measurement control device is responsible for the logical judgment of whether to start the acoustic module; when the sampling measurement system touches the bottom, the accelerometer feeds back a negative value to the acceleration measurement circuit, and the measurement control device immediately starts the acquisition work of the acoustic module, and re-enters the standby mode after the acquisition work is completed.

[0094] 8. During the entire measurement process, the power module provides the DC low-voltage power supply and acoustic wave excitation high-voltage power supply required for the sampling measurement system; the measurement control device completes the measurement process control, data acquisition, data storage and other functions; the measurement control device uses a digital signal processor as the core, and realizes data exchange of equipment attitude parameters, height from the bottom and acceleration parameters with the sensor system through the seabed transmission interface, and realizes the timing control of the measurement control process through the FPGA control chip. First, the acceleration acquisition module is driven to collect acceleration parameters, and it is judged whether the equipment has touched the bottom based on the acceleration parameters. If it has touched the bottom, the inclinometer, ranging transducer and acoustic module are started. During the entire operation of the acoustic module, the inclinometer continuously collects attitude parameters and the ranging transducer continuously collects height from the bottom parameters until the acoustic module enters standby mode. The acoustic module includes a receiving amplifier circuit, a transmitting control circuit, a high-speed A / D, and a TF card storage. The transmitting control circuit excites the generation of an acoustic wave signal, which is amplified and then excited to the transmitting transducer. After the acoustic signal propagates in the seabed sediment, it is received by the receiving transducer, amplified by the receiving amplifier circuit, digitized by the high-speed A / D, and stored in the TF card.

[0095] 9. When the instrument touches the bottom and the instantaneous start system starts the acoustic characteristic measurement, the system begins acoustic measurement. The acoustic measurement module excites the transmitting transducer to generate a sound wave signal according to the preset parameters. The sound wave signal passes through the seabed sediment and reaches different receiving transducers. After the receiving transducer receives the sound wave signal, it is transmitted back to the acoustic measurement module through the signal cable, and the sound wave data is stored in the measurement module. When the transmitting transducer excites the sound wave signal, a first absorbing silica gel is set between the transmitting transducer and the mounting base to prevent the sound wave from being transmitted from the transmitting transducer to the receiving transducer along the sampling outer tube; at the same time, a barrier groove is processed on the sampling outer tube of the sampling measurement system, and a second absorbing silica gel is set between the receiving transducer and the sampling outer tube. The barrier groove and the second absorbing silica gel enable the receiving transducer to only receive the sound waves transmitted by the transmitting transducer through the bottom sediment, so as to accurately measure the acoustic characteristics of the bottom sediment.

[0096] 10. The principle of the entire acoustic in-situ measurement is: there is one acoustic characteristic transmitting transducer and eight receiving transducers, which are arranged vertically at a certain interval; when measuring acoustic characteristics, in order to improve the measurement accuracy, the average sound velocity measurement is used as the measured sound velocity. The sound velocity is calculated by the difference in the transmission time of the sound wave reaching different receivers and the distance difference between the transmitting transducer and the different receivers.

[0097] 11. Recover the armored cable, recover the sampling and measuring system to the ship deck, and use the host computer to export the data obtained by the sampling and measuring system, including the attitude data collected by the inclinometer, the height from the bottom data collected by the ranging transducer, the acceleration parameters collected by the accelerometer, the start-up time and standby time of the acoustic module recorded by the measurement control device, and the acoustic data collected by the acoustic module, and process and analyze the obtained acoustic characteristic data; if the obtained acoustic characteristic data is abnormal, re-sampling measurement can be performed;

[0098] 12. When the sampling and measuring system returns to the ship deck and needs to take out sediment samples, unscrew the sampling head from the sampling inner tube and remove the sampling liner from the sampling inner tube. If the length of the sediment obtained is too short, re-sample and measure.

[0099] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An acoustic in-situ sampling and measurement system for seafloor sediments, characterized in that: include: Measuring devices, sampling devices, measurement control devices and support devices; The supporting device is connected to the mother ship via cables; The sampling device is arranged at the bottom of the supporting device, and the sampling device is used to obtain seabed sediment samples; The measuring device is arranged on the supporting device, and the measuring device is used for performing acoustic measurement; The measuring device specifically comprises: an acoustic module, an acceleration measuring module and a distance measuring module; the acoustic module, the acceleration measuring module and the distance measuring module are all connected to the measuring control device; the acoustic module is used to measure the acoustic characteristics of seabed sediments; The acoustic module specifically comprises: a transmitting transducer and a receiving transducer; the transmitting transducer is arranged on the supporting device, and the receiving transducer is arranged on the sampling device; The acceleration measurement module specifically includes: an accelerometer and an acceleration measurement circuit; the acceleration measurement circuit is connected to the accelerometer and the measurement control device respectively; the acceleration measurement circuit is used to identify positive and negative changes in acceleration; the acceleration measurement module is used to identify positive and negative changes in acceleration; The distance measuring module is used to measure the height from the seabed; The measurement control device is used to control the acoustic module to measure the acoustic characteristics of seabed sediments when the acceleration measurement module identifies that the acceleration changes from positive to negative; the measurement control device is also used to store the height information from the seabed transmitted by the distance measurement module; The sampling device specifically comprises: a sampling outer tube, a sampling inner tube, a sampling liner, a sampling head and a non-return spring sheet; the sampling inner tube is sleeved on the sampling liner, and the sampling outer tube is sleeved on the sampling inner tube; the sampling head is arranged at the bottom of the sampling outer tube, and the top of the sampling outer tube is arranged at the bottom of the supporting device; the non-return spring sheet is arranged inside the sampling head, and the sediment enters the sampling liner through the sampling head, and the non-return spring sheet is used to prevent the sediment entering the sampling liner from falling off; a plurality of blocking grooves are opened on the outer wall of the sampling outer tube, and the receiving transducer is arranged in the blocking grooves; The acoustic module further includes: a first wave-absorbing silica gel and a second wave-absorbing silica gel; the first wave-absorbing silica gel is connected to the transmitting transducer, and the first wave-absorbing silica gel is used to prevent sound waves from being transmitted from the transmitting transducer to the receiving transducer along the sampling outer tube; the second wave-absorbing silica gel is arranged between the blocking groove and the receiving transducer, and the second wave-absorbing silica gel is used to enable the receiving transducer to only receive the sound waves transmitted by the transmitting transducer through the seabed sediments; The measurement control device is arranged on the supporting device, the measurement control device is electrically connected to the measuring device, and the measurement control device is used to control the measuring device to perform acoustic measurement.

2. The seabed sediment acoustic in-situ sampling and measurement system according to claim 1, characterized in that: The system further comprises: Water main control system; The above-water main control system is connected to the measuring device and the measuring control device respectively, and the above-water main control system is used to issue control instructions and obtain underwater measuring data.

3. The seabed sediment acoustic in-situ sampling and measurement system according to claim 1, characterized in that: The measuring device further comprises: Inclinometer; The inclinometer is arranged on the supporting device and is connected to the measuring control device; the inclinometer is used to monitor whether the sampling device is vertically inserted into the seabed.

4. The seabed sediment acoustic in-situ sampling and measurement system according to claim 1, characterized in that: The supporting device specifically comprises: Load-bearing brackets and mounting bases; The load-bearing bracket is arranged on the carrying base, and the top of the load-bearing bracket is connected to the mother ship through a cable; the measuring device and the measuring control device are both arranged on the upper surface of the carrying base, and the sampling device is arranged on the lower surface of the carrying base.

5. The seabed sediment acoustic in-situ sampling and measurement system according to claim 4, characterized in that: The system further comprises: Lead weights; The weighted lead block is arranged on the upper surface of the carrying base, and the weighted lead block is used to make the sampling device insert into the seabed sediment to reach a preset depth.

6. The seabed sediment acoustic in-situ sampling and measurement system according to claim 3, characterized in that: The system further comprises: Underwater circuit sealed cabin; The underwater circuit sealed cabin is arranged on the supporting device, and the measurement control device, the accelerometer, the acceleration measurement circuit and the inclinometer are all arranged in the underwater circuit sealed cabin.

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