A device and method for detecting oil spill thickness at sea based on an underwater robot platform

Abstract

The application belongs to the technical field of offshore oil spill detection, and particularly relates to an offshore oil spill thickness detection device and method based on an underwater robot platform. The device comprises an ultrasonic signal processing unit, an underwater robot control unit, an underwater robot platform, an ultrasonic measurement unit arranged on the underwater robot platform, a positioning and navigation unit, and a control unit. The ultrasonic measurement unit is used for receiving ultrasonic signals and sending the ultrasonic signals to the ultrasonic signal processing unit. The positioning and navigation unit is used for positioning the underwater robot platform. The control unit is used for controlling the underwater robot platform to move according to a movement instruction. The ultrasonic signals sent by the ultrasonic measurement unit are sent to the ultrasonic signal processing unit. The positioning and navigation unit is also used for recording position information and a movement track of the underwater robot platform in real time and sending the position information and the movement track to the underwater robot control unit. The underwater robot platform is used to measure the thickness of an oil layer from underwater, so that the influence of natural environmental factors on the measurement accuracy is reduced.

Description

Technical Field

[0001] This invention belongs to the field of marine oil spill detection technology, specifically a marine oil spill thickness detection device and method based on an underwater robot platform. Background Technology

[0002] With the increasing exploitation of deep-sea oil and gas resources and the growing reliance on offshore crude oil transportation in my country, the risk of marine oil spills is increasing year by year. Marine oil spills not only cause severe economic losses but also inflict irreparable damage on marine resources and the marine ecosystem, becoming a significant factor endangering the marine environment. Regardless of the disposal methods used for marine oil spills, it is essential to first determine the thickness of the spill to ascertain the amount. Therefore, accurate measurement of the thickness of floating oil layers on the sea surface is a crucial research area in this field.

[0003] Currently, extensive experimental research has been conducted both domestically and internationally on methods and technologies for detecting oil spill thickness, including infrared hyperspectral imaging, high-resolution remote sensing satellites, laser ultrasound, and antenna resistance. However, these technologies are generally concentrated in the laboratory technology verification stage, and large-scale testing under simulated real-world environments has not yet been carried out. Furthermore, they all have certain technical limitations. For example, laser ultrasound measurement methods are highly susceptible to the influence of natural factors such as wind, waves, and ocean currents, resulting in low accuracy of the measurement results. Infrared hyperspectral imaging and high-resolution remote sensing technologies can only measure relatively thin oil films (<1 mm) and cannot accurately measure the thickness of thicker oil layers. Therefore, developing a practically applicable oil spill thickness detection device is a significant need in this field. Summary of the Invention

[0004] The purpose of this invention is to provide a precise detection device for the thickness of marine oil spills based on ultrasonic detection technology using an underwater robot as a platform. This device can quickly detect the thickness of the oil spill layer with high accuracy, thus overcoming the shortcomings of the above-mentioned marine oil spill detection methods.

[0005] The technical solution adopted by the present invention to achieve the above objectives is: a marine oil spill thickness detection device based on an underwater robot platform, comprising: an ultrasonic signal processing unit, an underwater robot control unit, an underwater robot platform, and an ultrasonic measurement unit, a positioning and navigation unit, and a control unit installed on the underwater robot platform;

[0006] The ultrasonic measurement unit is used to receive ultrasonic signals reflected from the upper and lower surfaces of the marine oil layer and send them to the ultrasonic signal processing unit via the control unit;

[0007] The positioning and navigation unit uses an acoustic positioning device to locate the underwater robot platform's position underwater and records the underwater robot platform's position information and movement trajectory in real time. The information is then sent to the underwater robot control unit for real-time display via the control unit.

[0008] The control unit is used to control the motion of the underwater robot platform according to the motion commands sent by the underwater robot control unit; to receive ultrasonic signals sent by the ultrasonic measurement unit, preprocess them, and send them to the ultrasonic signal processing unit through the signal transmission cable; and to receive the real-time recorded position information and motion trajectory of the underwater robot platform from the positioning and navigation unit and send them to the underwater robot control unit for real-time display.

[0009] The underwater robot control unit is located above the water surface and is used to receive the position information and movement trajectory of the underwater robot platform from the positioning and navigation unit in real time via signal transmission cable, display the underwater robot platform in real time, and send movement commands to the control unit according to the task requirements to control the movement of the underwater robot platform in real time.

[0010] The underwater robot control unit sends control commands to the control unit to control the ultrasonic measurement unit to transmit and receive ultrasonic signals.

[0011] The ultrasonic signal processing unit is located above the water surface. It is used to collect and store the ultrasonic signals acquired by the ultrasonic measurement unit, and to analyze and process the signals using ultrasonic signal processing algorithms to obtain the thickness of the oil layer.

[0012] The ultrasonic measurement unit includes: an ultrasonic transmitter and receiver, and an ultrasonic probe;

[0013] The ultrasonic transmitter and receiver are located inside the underwater robot platform and are respectively connected to the ultrasonic probe and the control unit.

[0014] The ultrasonic probe is located on the top of the underwater robot platform. There are one or more ultrasonic probes, and the emission direction of the ultrasonic probe is perpendicular to the water surface.

[0015] The ultrasonic probe is a water immersion non-focused ultrasonic probe with a working center frequency of 1.0MHz to 15MHz.

[0016] The ultrasonic transmitter and receiver are ultrasonic instruments with at least one channel, and the operating frequency of the ultrasonic instrument is 1.0MHz to 20MHz.

[0017] The underwater robot platform is positioned at a depth of less than 2 meters from the water surface.

[0018] The ultrasonic signal processing unit includes: a storage module, a signal processing module, and a visualization module connected in sequence;

[0019] The storage module is used to receive and store the ultrasonic signals sent by the ultrasonic measurement unit, and wait for the signal processing module to call them.

[0020] The signal processing module is used to call the ultrasonic signal stored in the storage module, analyze the ultrasonic signal, calculate the oil layer thickness at a single location point or multiple locations, send the oil layer thickness at a single location point to the visualization module for display, and combine the oil layer thickness at multiple locations with the positioning and navigation data to obtain an oil layer thickness distribution map of the oil spill coverage area, which is then sent to the visualization module for real-time display.

[0021] A detection method for marine oil spill thickness based on an underwater robot platform includes the following steps:

[0022] S1: The ultrasonic measurement unit emits ultrasonic waves through an ultrasonic probe and collects ultrasonic signals reflected from the upper and lower surfaces of the oil layer. At the same time, the positioning and navigation unit records the position information of the underwater robot platform at that point and sends it to the control unit.

[0023] S2: The control unit transmits the collected ultrasonic signals and the underwater robot's position information to the ultrasonic signal processing unit and the underwater robot control unit for storage via signal transmission cables.

[0024] S3: The ultrasonic signal processing unit uses an ultrasonic signal processing algorithm to process the ultrasonic signal, obtain the round-trip propagation time Δt of the ultrasonic wave in the oil layer, and obtain the thickness of the oil layer based on the round-trip propagation time Δt of the ultrasonic wave in the oil layer.

[0025] S4: The underwater robot control unit controls the movement of the underwater robot platform. At the same time, the ultrasonic measurement unit scans the designated oil spill coverage area, collects ultrasonic reflection signals from each point, and the positioning and navigation unit controls the position of the underwater robot, tracks and records the position information and movement trajectory of each point, and realizes the scanning of the specific oil spill coverage area.

[0026] S5: The control unit transmits the ultrasonic data and the underwater robot's position information back to the ultrasonic signal processing unit and the underwater robot control unit in real time for storage. The ultrasonic signal processing unit calculates the oil layer thickness at each location point and combines it with the positioning and navigation data to obtain an oil layer thickness distribution map of the oil spill coverage area.

[0027] When the ultrasonic signal processing unit collects ultrasonic signals reflected from the upper and lower surfaces of the oil layer, it emits and collects multiple ultrasonic signals at each location point using a set ultrasonic emission frequency. The ultrasonic signal processing unit obtains multiple oil layer thickness data and calculates the average and standard deviation of the oil layer thickness within a set time range. The oil layer thickness at that location is characterized by the statistical data of the oil layer thickness.

[0028] In step S3, when the ultrasound signal processing algorithm uses the peak-to-peak method, specifically:

[0029] By calculating the time difference between the reflected signal amplitudes of the ultrasonic wave on the upper and lower surfaces of the oil layer, the propagation time of the ultrasonic wave in one round trip within the oil layer is calculated as follows:

[0030] Δt=t2-t1

[0031] Where t2 and t1 are the time points corresponding to the peak values ​​of the signals on the upper and lower surfaces of the oil layer, respectively;

[0032] The thickness of the oil layer can be obtained from the round-trip propagation time Δt of the ultrasonic wave in the oil layer, i.e.:

[0033] d = v·Δt / 2

[0034] Where v is the propagation speed of the ultrasonic wave in the oil spill layer, and Δt is the propagation time of one round trip of the ultrasonic wave in the oil layer.

[0035] In step S3, when the ultrasound signal processing algorithm uses the quadratic correlation method, specifically:

[0036] (1) Two time gates were used to extract the ultrasonic reflection signals from the upper and lower surfaces of the oil layer, respectively;

[0037] (2) Perform autocorrelation operation on the reflection signal of the lower surface of the oil layer to obtain the autocorrelation signal; and perform a cross-correlation operation on the reflection signal of the lower surface of the oil layer and the reflection signal of the upper surface of the oil layer to obtain a cross-correlation signal;

[0038] (3) Perform a second cross-correlation operation on the autocorrelation signal and the first cross-correlation signal. The time point corresponding to the peak value of the second cross-correlation signal is the round-trip propagation time Δt of the ultrasonic wave in the oil layer.

[0039] (4) The thickness of the oil layer can be obtained from the round-trip propagation time Δt of the ultrasonic wave in the oil layer, i.e.:

[0040] d = v·Δt / 2

[0041] Where v is the propagation speed of the ultrasonic wave in the oil spill layer, and Δt is the propagation time of one round trip of the ultrasonic wave in the oil layer.

[0042] The present invention has the following beneficial effects and advantages:

[0043] 1. This invention uses ultrasonic measurement technology to obtain the thickness of the oil layer by multiplying the propagation time of the ultrasonic wave in the oil layer by the propagation speed of the ultrasonic wave in the oil layer, which can achieve accurate measurement of thick oil layers;

[0044] 2. This invention uses an underwater robot platform to measure the thickness of the oil layer underwater, which can reduce the impact of natural environmental factors such as wind and waves on the measurement accuracy and improve the measurement accuracy;

[0045] 3. The underwater robot platform used in this invention can not only carry out single-point in-situ detection of oil layer thickness, but also quickly scan a region to obtain a distribution map of oil layer thickness;

[0046] 4. This invention overcomes the problem that existing detection technologies and methods cannot accurately detect the thickness of thick oil films, laying a technical foundation for the measurement of marine oil spill volume and the formulation of oil spill response plans. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the oil layer thickness detection device for the underwater robot platform of the present invention;

[0048] Figure 2 This is a schematic diagram illustrating the propagation of ultrasonic waves in an oil layer and the corresponding ultrasonic signals according to the present invention;

[0049] Figure 3 This is a schematic diagram of the quadratic correlation method signal processing algorithm of the present invention;

[0050] Figure 4 This is a schematic diagram of the ultrasonic measurement method for oil spill layer thickness of the underwater robot platform of the present invention.

[0051] Wherein, 1 is the underwater robot platform, 2 is the ultrasonic probe, 3 is the ultrasonic transmitter and receiver, 4 is the positioning and navigation unit, 5 is the control unit, 6 is the signal transmission cable, 7 is the ultrasonic signal processing unit, and 8 is the underwater robot control unit; 9 is the reflected echo of the ultrasonic wave at the interface between the lower surface of the oil layer and water, 10 is the reflected echo of the ultrasonic wave at the interface between the upper surface of the oil layer and air, 11 is the ultrasonic wave reflected twice in the oil layer, 12 is the reflected echo of the ultrasonic wave at the interface between the lower surface of the oil layer and water, 13 is the reflected echo of the ultrasonic wave at the interface between the upper surface of the oil layer and air, 14 is the signal obtained by autocorrelation operation of ultrasonic signal 12, 15 is the signal obtained by cross-correlation operation of ultrasonic signal 12 and ultrasonic signal 13, and 16 is the signal obtained by cross-correlation operation of autocorrelation signal 14 and cross-correlation signal 15. Detailed Implementation

[0052] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings and embodiments. The embodiments used are for illustrative purposes only and do not limit the scope of application of the present invention.

[0053] Due to the different acoustic impedances of ultrasound waves in oil, water, and air, when ultrasound waves are transmitted to the interface between oil and water, and between oil and air, some of the energy will be reflected back due to the difference in acoustic impedance. By calculating the time difference between the signals reflected back from the upper and lower surfaces of the oil layer, the propagation time of the ultrasound waves in the oil layer can be obtained. Multiplying this time by the propagation speed of the ultrasound waves in the oil layer can give the thickness of the oil layer.

[0054] Based on the above technical principles, this invention designs a marine oil spill thickness detection device using an underwater robot as a platform. This device employs cable control to move the underwater robot below the oil-covered area, and uses its onboard ultrasonic measurement system to accurately measure the oil layer thickness. Figure 1 As shown, the device includes: an underwater robot platform 1, an ultrasonic measurement unit including: an ultrasonic probe 2 and an ultrasonic transmitter and receiver 3, a positioning and navigation unit 4, a control unit 5, a signal transmission cable 6, an ultrasonic signal processing unit 7, and an underwater robot control unit 8.

[0055] The ultrasonic measurement unit is used to receive ultrasonic signals reflected from the upper and lower surfaces of the marine oil layer and send them to the ultrasonic signal processing unit 7 via the control unit 5.

[0056] The positioning and navigation unit 4 uses an acoustic positioning device, namely an ultra-short baseline underwater acoustic positioning system, to locate the underwater robot platform 1 in the underwater environment and record the position information and movement trajectory of the underwater robot platform 1 in real time. The information is then sent to the underwater robot control unit 8 for real-time display through the control unit 5.

[0057] The control unit 5 is used to control the motion of the underwater robot platform 1 according to the motion command sent by the underwater robot control unit 8; to receive the ultrasonic signal sent by the ultrasonic measurement unit and send it to the ultrasonic signal processing unit 7 through the signal transmission cable 6; and to receive the position information and motion trajectory of the underwater robot platform 1 recorded in real time by the positioning and navigation unit (4) and send them to the underwater robot control unit 8 for real-time display.

[0058] The underwater robot control unit 8 is located above the water surface and is used to receive the position information and movement trajectory of the underwater robot platform 1 fed back by the positioning and navigation unit 4 in real time through the signal transmission cable 6, display the underwater robot platform 1 in real time, and send movement commands to the control unit 5 according to the task requirements to control the movement of the underwater robot platform 1 in real time.

[0059] The underwater robot control unit 8 sends control commands to the control unit 5 to control the ultrasonic measurement unit to transmit and receive ultrasonic signals;

[0060] The ultrasonic signal processing unit 7 is located above the water surface. It is used to collect and store the ultrasonic signals acquired by the ultrasonic measurement unit, and to analyze and process the signals using ultrasonic signal processing algorithms to obtain the thickness of the oil layer.

[0061] The underwater robot platform 1, serving as a transport platform, integrates an ultrasonic measurement system including an ultrasonic probe 2 and ultrasonic transmitter and receiver 3, as well as a positioning and navigation unit 4. To ensure the strength of the received ultrasonic signals, the underwater robot maintains a depth of less than 2 meters during the oil layer thickness detection process, enabling it to adopt two observation modes: fixed-point fine in-situ measurement and area scanning measurement.

[0062] The ultrasonic transmitter and receiver 3 are located inside the underwater robot platform 1 and are respectively connected to the ultrasonic probe 2 and the control unit 5. The ultrasonic probe 2 is located on the top of the underwater robot platform 1, and the emission direction of the ultrasonic probe 2 is perpendicular to the water surface.

[0063] The ultrasonic measurement unit has at least one multi-channel ultrasonic transmitter and receiver 3 and one or more ultrasonic probes 2. The ultrasonic transmitter and receiver 3 can transmit and receive ultrasonic signals sequentially or synchronously from multiple channels. Each channel can be used for transmission or reception individually, or for both transmission and reception simultaneously. Each channel is connected to an ultrasonic probe 2, which can be of various types and frequency ranges. In a preferred embodiment of this device, the operating center frequency of the ultrasonic probe 2 is 1.0MHz to 15MHz. The ultrasonic transmitter and receiver are two-channel ultrasonic transducers manufactured by PeakNDT (UK), with an operating frequency range of 1.0MHz to 20MHz. Each channel is connected to an ultrasonic probe, which is positioned at the front and rear ends of the underwater robot. Each probe is used for both transmission and reception of ultrasonic waves. The ultrasonic probes are water-immersion non-focused ultrasonic probes manufactured by Olympus (Japan), with center frequencies of 2.25MHz and 5.0MHz, respectively.

[0064] The positioning and navigation unit 4 uses inertial navigation or ultra-short baseline navigation to transmit the underwater robot's position information back to the ultrasonic signal processing unit 7 and the underwater robot control unit 8 on the mother ship's computer in real time via the control unit 5 and signal transmission cable 6. At the same time, it can perform high-precision in-situ control and positioning of the underwater robot platform 1 near the water surface, as well as high-precision lateral line tracking control in the near-water surface area.

[0065] Control unit 5 is a control system that can not only control the movement of the underwater robot, but also adjust and set the parameters of the ultrasonic transmitter and receiver 3 through the signal transmission cable 6, and transmit the received ultrasonic signals and the position information of the underwater robot back to the mother ship computer at high speed for data storage, signal processing and real-time display of results.

[0066] The ultrasonic signal processing unit 7 is installed on the computer of the surface mother ship. It can at least realize high-speed storage of received ultrasonic signals and analyze and process the collected signals through ultrasonic signal processing algorithms.

[0067] The ultrasonic signal processing unit 7 includes: a storage module, a signal processing module, and a visualization module connected in sequence;

[0068] The storage module is used to receive and store the ultrasonic signals sent by the ultrasonic measurement unit, waiting for the signal processing module to call them.

[0069] The signal processing module is used to call the ultrasonic signals stored in the storage module, analyze the ultrasonic signals, and calculate the oil layer thickness at a single or multiple location points. The oil layer thickness at a single location point is sent to the visualization module for display, and the oil layer thickness at multiple locations is combined with the positioning and navigation data to obtain an oil layer thickness distribution map of the oil spill coverage area, which is then sent to the visualization module for real-time display.

[0070] As a preferred embodiment of this unit, the signal processing method includes peak-to-peak method and quadratic correlation method. By analyzing and processing the ultrasonic signal, the propagation time of ultrasonic waves in the oil layer can be accurately measured. The oil layer thickness can be accurately calculated using the oil layer thickness calculation formula. The ultrasonic signal, oil layer thickness, and underwater robot position information can be visualized and displayed in real time.

[0071] The underwater robot control unit 8 is a control system that controls the movement of the underwater robot according to the needs of the mission. It achieves precise control of the underwater robot's position, depth, attitude, direction of movement, and trajectory in the water through the control unit 5.

[0072] Figure 2The diagram illustrates the propagation of ultrasonic waves underwater and in oil reservoirs, the morphology of the ultrasonic signals, and a peak-to-peak signal processing method. It includes ultrasonic signal 9 reflected from the interface between the lower surface of the oil reservoir and the water, ultrasonic signal 10 reflected from the interface between the upper surface of the oil reservoir and the air, and ultrasonic wave 11 reflected twice in the oil reservoir. The time points corresponding to the peak values ​​of the reflected signals from the upper and lower surfaces of the oil reservoir and the second reflection signal are t1, t2, and t3, respectively. In a preferred embodiment of the invention, a peak-to-peak signal processing algorithm is used to calculate the propagation time Δt of the ultrasonic wave in the oil reservoir for one round trip. Theoretically, the propagation time Δt can be calculated by the difference between the peak time points of two adjacent signals, Δt = t2 - t1 or Δt = t3 - t2. The oil reservoir thickness d = v·(t2 - t1) / 2 = v·(t3 - t2) / 2, where v is the propagation speed of the ultrasonic wave in the oil reservoir. Furthermore, as a preferred embodiment of the system, in actual testing, due to the attenuation of ultrasonic signals and the influence of natural factors such as wind and waves, it is often difficult to measure secondary reflection signals. Therefore, the oil layer thickness is generally calculated by using the time points corresponding to the peak values ​​of the reflection signals on the upper and lower surfaces of the oil layer.

[0073] The undulations of the water surface caused by ocean waves and the movement of underwater robot platforms often alter the peak phase of ultrasonic signals, leading to a decrease in the accuracy of propagation time measurements. To overcome the problem that the accuracy of peak-to-peak method measurements is easily affected by the environment, this invention proposes an ultrasonic signal processing algorithm based on the quadratic correlation method. Figure 3 The diagram shown is a schematic representation of the quadratic correlation method, which serves as a preferred embodiment of the present invention. Figure 3 The image shows the ultrasonic signal reflected from a 10mm thick oil layer, collected using a water-immersion ultrasonic probe with a center frequency of 5MHz. Two time gates were used to extract the ultrasonic reflection signal 12 from the lower surface and 13 from the upper surface of the oil layer. Then, an autocorrelation operation was performed on the ultrasonic reflection signal 12 from the lower surface to obtain signal 14. A first cross-correlation operation was performed between ultrasonic signals 12 and 13 to obtain signal 15. Finally, a second cross-correlation operation was performed between the autocorrelation signal 14 and the first cross-correlation signal 15 to obtain signal 16. The time point corresponding to the peak value of signal 16 is the round-trip propagation time Δt of the ultrasonic wave in the oil layer. The oil layer thickness was calculated using the formula d = v·Δt / 2, where v is the propagation speed of the ultrasonic wave in the oil spill layer.

[0074] In addition, another object of the present invention is to provide a method for measuring the thickness of an oil spill layer based on the above-described apparatus, characterized in that: [The following is a description of the method]. Figure 4 As shown, it includes the following steps:

[0075] S1: The underwater robot platform 1 integrates an ultrasonic measurement unit and a positioning and navigation unit and moves to the area below the oil spill layer via remote control. The ultrasonic measurement unit emits ultrasonic waves through the ultrasonic probe 2 and collects ultrasonic signals reflected from the upper and lower surfaces of the oil layer. At the same time, the positioning and navigation unit 4 records the position information of the underwater robot platform 1 at that point and sends it to the control unit 5.

[0076] S2: The collected ultrasonic signals and the position information of the underwater robot platform 1 are transmitted to the mother ship computer for storage via the signal transmission cable 6. Then, ultrasonic signal processing algorithms such as peak-to-peak method or quadratic correlation method are used to process the ultrasonic signals, calculate the propagation time Δt of the ultrasonic wave in the oil layer, and calculate the thickness of the oil layer using the oil layer thickness calculation formula d=v·Δt / 2, where v is the propagation speed of the ultrasonic wave in the oil spill layer.

[0077] S3: The underwater robot control unit 8 controls the movement of the underwater robot platform 1. At the same time, the ultrasonic measurement unit scans the designated oil spill coverage area and collects ultrasonic reflection signals from each point. The positioning and navigation unit 4 positions and controls the underwater robot, tracks and records the position information and movement trajectory of each point, and realizes the scanning of the specific oil spill coverage area.

[0078] S4: The control unit 5 transmits the ultrasonic data and the underwater robot's position information back to the ultrasonic signal processing unit 7 and the underwater robot control unit 8 in real time for storage. The ultrasonic signal processing unit 7 calculates the oil layer thickness at each location point and combines the positioning and navigation data to obtain the oil layer thickness distribution map of the oil spill coverage area.

[0079] S5: To reduce the impact of natural factors such as wind and waves, and adverse factors such as the movement of the underwater robot platform 1 on the measurement accuracy, a high-frequency ultrasonic transmission frequency is set to transmit and collect multiple ultrasonic signals at each location point to obtain multiple oil layer thickness data. The average value and standard deviation of the oil layer thickness are calculated within a certain time range, and the oil layer thickness at that location is characterized by the statistical data of oil layer thickness.

[0080] This invention overcomes the problem that existing detection technologies and methods cannot accurately detect the thickness of thick oil films, laying a technical foundation for the measurement of marine oil spill volume and the formulation of oil spill response plans.

[0081] In this specification, the present invention has been described with reference to specific embodiments. These embodiments are preferred embodiments of the present patent and are not intended to limit the scope of the invention. It should be noted that the present invention is not limited to the specific embodiments described above. Improvements, variations, combinations, substitutions, etc., made by those skilled in the art without departing from the principles of the present invention are all within the scope of protection claimed in the claims of the present invention.

Claims

1. A marine oil spill thickness detection device based on an underwater robot platform, characterized in that, include: The ultrasonic signal processing unit (7), the underwater robot control unit (8), the underwater robot platform (1), and the ultrasonic measurement unit, the positioning and navigation unit (4), and the control unit (5) installed on the underwater robot platform (1); The ultrasonic measurement unit is used to receive ultrasonic signals reflected from the upper and lower surfaces of the marine oil layer and send them to the ultrasonic signal processing unit (7) via the control unit (5); The positioning and navigation unit (4) uses an acoustic positioning device to locate the underwater robot platform (1) underwater and records the position information and movement trajectory of the underwater robot platform (1) in real time. The information is then sent to the underwater robot control unit (8) for real-time display through the control unit (5). The control unit (5) is used to control the motion of the underwater robot platform (1) according to the motion command sent by the underwater robot control unit (8); to receive the ultrasonic signal sent by the ultrasonic measurement unit, preprocess it, and send it to the ultrasonic signal processing unit (7) through the signal transmission cable (6); and to receive the real-time recorded position information and motion trajectory of the underwater robot platform (1) from the positioning and navigation unit (4) and send it to the underwater robot control unit (8) for real-time display. The underwater robot control unit (8) is located above the water surface and is used to receive the position information and movement trajectory of the underwater robot platform (1) fed back by the positioning and navigation unit (4) in real time through the signal transmission cable (6), display the underwater robot platform (1) in real time, and send movement commands to the control unit (5) according to the task requirements to control the movement of the underwater robot platform (1) in real time. The underwater robot control unit (8) sends control commands to the control unit (5) to control the ultrasonic measurement unit to transmit and receive ultrasonic signals; The ultrasonic signal processing unit (7) is located above the water surface and is used to collect and store the ultrasonic signals acquired by the ultrasonic measurement unit, and to analyze and process the signals using ultrasonic signal processing algorithms to obtain the thickness of the oil layer.

2. The marine oil spill thickness detection device based on an underwater robot platform according to claim 1, characterized in that, The ultrasonic measurement unit includes: an ultrasonic transmitter and receiver (3) and an ultrasonic probe (2); The ultrasonic transmitter and receiver (3) are located inside the underwater robot platform (1) and are respectively connected to the ultrasonic probe (2) and the control unit (5); The ultrasonic probe (2) is located on the top of the underwater robot platform (1). There are one or more ultrasonic probes (2), and the emission direction of the ultrasonic probe (2) is perpendicular to the water surface.

3. The marine oil spill thickness detection device based on an underwater robot platform according to claim 2, characterized in that, The ultrasonic probe (2) is a water immersion non-focused ultrasonic probe with a working center frequency of 1.0MHz to 15MHz.

4. The marine oil spill thickness detection device based on an underwater robot platform according to claim 2, characterized in that, The ultrasonic transmitter and receiver (3) is an ultrasonic instrument with at least one channel, and the working frequency of the ultrasonic instrument is 1.0MHz to 20MHz.

5. The marine oil spill thickness detection device based on an underwater robot platform according to claim 1, characterized in that, The underwater robot platform (1) is located at a depth of less than 2m from the water surface.

6. The marine oil spill thickness detection device based on an underwater robot platform according to claim 1, characterized in that, The ultrasonic signal processing unit (7) includes: a storage module, a signal processing module, and a visualization module connected in sequence; The storage module is used to receive and store the ultrasonic signals sent by the ultrasonic measurement unit, and wait for the signal processing module to call them. The signal processing module is used to call the ultrasonic signal stored in the storage module, analyze the ultrasonic signal, calculate the oil layer thickness at a single location point or multiple locations, send the oil layer thickness at a single location point to the visualization module for display, and combine the oil layer thickness at multiple locations with the positioning and navigation data to obtain an oil layer thickness distribution map of the oil spill coverage area, which is then sent to the visualization module for real-time display.

7. The detection method of a marine oil spill thickness detection device based on an underwater robot platform according to claim 1, characterized in that, Includes the following steps: S1: The ultrasonic measurement unit emits ultrasonic waves through the ultrasonic probe (2) and collects ultrasonic signals reflected from the upper and lower surfaces of the oil layer. At the same time, the positioning and navigation unit (4) records the position information of the underwater robot platform (1) at that point and sends it to the control unit (5). S2: The control unit (5) transmits the collected ultrasonic signals and the underwater robot's position information to the ultrasonic signal processing unit (7) and the underwater robot control unit (8) for storage via the signal transmission cable (6); S3: The ultrasonic signal processing unit (7) uses an ultrasonic signal processing algorithm to process the ultrasonic signal, obtains the round-trip propagation time Δt of the ultrasonic wave in the oil layer, and obtains the thickness of the oil layer based on the round-trip propagation time Δt of the ultrasonic wave in the oil layer. S4: The underwater robot control unit (8) controls the movement of the underwater robot platform (1). At the same time, the ultrasonic measurement unit scans the designated oil spill coverage area, collects ultrasonic reflection signals from each point, and the positioning and navigation unit (4) controls the position of the underwater robot, tracks and records the position information and movement trajectory of each point, and realizes the scanning of the specific oil spill coverage area. S5: The control unit (5) transmits the ultrasonic data and the underwater robot position information back to the ultrasonic signal processing unit (7) and the underwater robot control unit (8) in real time for storage, and calculates the oil layer thickness at each location point through the ultrasonic signal processing unit (7), and obtains the oil layer thickness distribution map of the oil spill coverage area by combining the positioning and navigation data.

8. The detection method for a marine oil spill thickness detection device based on an underwater robot platform according to claim 7, characterized in that, When the ultrasonic signal processing unit (7) collects ultrasonic signals reflected from the upper and lower surfaces of the oil layer, it emits and collects multiple ultrasonic signals at each location point using a set ultrasonic emission frequency. The ultrasonic signal processing unit (7) obtains multiple oil layer thickness data and calculates the average and standard deviation of the oil layer thickness within a set time range. The oil layer thickness at that location is characterized by the statistical data of the oil layer thickness.

9. The detection method of a marine oil spill thickness detection device based on an underwater robot platform according to claim 7, characterized in that, In step S3, when the ultrasound signal processing algorithm uses the peak-to-peak method, specifically: By calculating the time difference between the reflected signal amplitudes of the ultrasonic wave on the upper and lower surfaces of the oil layer, the propagation time of the ultrasonic wave in one round trip within the oil layer is calculated as follows: Δt=t2-t1 Where t2 and t1 are the time points corresponding to the peak values ​​of the signals on the upper and lower surfaces of the oil layer, respectively; The thickness of the oil layer can be obtained from the round-trip propagation time Δt of the ultrasonic wave in the oil layer, i.e.: d = v·Δt / 2 Where v is the propagation speed of the ultrasonic wave in the oil spill layer, and Δt is the propagation time of one round trip of the ultrasonic wave in the oil layer.

10. The detection method of a marine oil spill thickness detection device based on an underwater robot platform according to claim 7, characterized in that, In step S3, when the ultrasound signal processing algorithm uses the quadratic correlation method, specifically: (1) Two time gates were used to extract the ultrasonic reflection signals from the upper and lower surfaces of the oil layer, respectively; (2) Perform autocorrelation operation on the reflection signal of the lower surface of the oil layer to obtain the autocorrelation signal; and perform a cross-correlation operation on the reflection signal of the lower surface of the oil layer and the reflection signal of the upper surface of the oil layer to obtain a cross-correlation signal; (3) Perform a second cross-correlation operation on the autocorrelation signal and the first cross-correlation signal. The time point corresponding to the peak value of the second cross-correlation signal is the round-trip propagation time Δt of the ultrasonic wave in the oil layer. (4) The thickness of the oil layer can be obtained from the round-trip propagation time Δt of the ultrasonic wave in the oil layer, i.e.: d = v·Δt / 2 Where v is the propagation speed of the ultrasonic wave in the oil spill layer, and Δt is the propagation time of one round trip of the ultrasonic wave in the oil layer.

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