Acousto-optic signal data fused sediment concentration monitoring device and method

Abstract

The invention discloses a sediment concentration monitoring device and method based on acousto-optic signal data fusion, and relates to the technical field of hydrological monitoring, the device comprises a frame and turbidimeter and hydrophone integrated equipment, the turbidimeter and hydrophone integrated equipment is installed in the center of the frame, the signal emission of the turbidimeter and hydrophone integrated equipment faces upwards and is perpendicular to the water surface, and the turbidimeter and hydrophone integrated equipment is installed in the frame. The frame is used for adjusting the underwater entry depth of the turbidimeter and hydrophone integrated equipment. According to the invention, the turbidimeter and the hydrophone are integrated with a cable through a fixed support structure and are installed at the bottom of a water body, according to an acoustic backscattering principle, a sediment concentration value is inverted by using an echo signal of the hydrophone, and meanwhile, turbidimeter data and hydrophone data are subjected to fusion processing to obtain a fused sediment concentration value. By fusing signal data of the turbidimeter and the hydrophone, the defects of a single sediment concentration measurement principle and method are overcome, the requirement for high-precision measurement of sediment concentration under the condition of different sediment particle sizes is met, and high-precision sediment concentration monitoring is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrological monitoring, and in particular to a sediment monitoring device and method for fusing acoustic and optical signal data. Background Art

[0002] Sediment concentration measurement is an important part of hydrological monitoring. By analyzing river sediment concentration data, relevant information on climate and environment can be obtained. Sediment concentration monitoring is of great significance to soil and water conservation, river and lake management, wetland function restoration, and pumped storage power station safety.

[0003] There are two main methods for monitoring sediment concentration, namely traditional methods and modern methods. The traditional method relies on collecting water on site, then filtering, weighing and calculating the water sample to obtain the sediment concentration value of the water body. The modern method mainly uses optical, acoustic, isotope and other sensors to indirectly observe sediment concentration.

[0004] Compared with traditional methods, modern methods have greatly reduced labor costs, but a single means of monitoring sediment concentration often has some inherent defects. Conditions such as sediment particle size, water temperature, and sediment concentration will have different effects on sensors based on different principles. The use of acoustic and optical signal data fusion can effectively improve the stability and accuracy of sediment concentration monitoring. Summary of the invention

[0005] The present invention provides a sediment monitoring device and method for fusing acoustic and optical signal data to solve the problems existing in the above-mentioned single sediment concentration monitoring means.

[0006] The specific plan is as follows: A sediment concentration monitoring device with acoustic and optical signal data fusion is characterized in that it includes a frame and an integrated device of a turbidity meter and a hydrophone, wherein the integrated device of the turbidity meter and the hydrophone is installed in the center of the frame, and its signal emission is upward and perpendicular to the water surface, and the frame is used to adjust the immersion depth of the integrated device of the turbidity meter and the hydrophone.

[0007] Furthermore, the turbidity meter and hydrophone integrated device includes a fixed bracket structure, and a turbidity meter and a hydrophone arranged on the fixed bracket structure, the turbidity meter and the hydrophone are fixed in the same plane, and a 5-core pluggable signal interface is reserved at the rear end, and the two 5-core pluggable signal interfaces are respectively connected to a first cable and a second cable, and the first cable and the second cable form a unified external interface through a first cable routing structure and a second cable routing structure respectively. The cable routing structure is used to route the cables.

[0008] Furthermore, an anti-fouling wiper is integrated in front of the turbidity meter, and the working mode of the wiper is fixedly activated and operated every time it is powered on. The hydrophone is a transceiver-transmitter ultrasonic transducer with an operating frequency of 1.5 MHz.

[0009] Furthermore, the turbidity meter and hydrophone integrated device also includes a data remote telemetry terminal, which is used to receive data output by the turbidity meter and the hydrophone, store the data locally, and then send it to the host computer through the wireless transmission module.

[0010] Furthermore, the frame includes two vertical bars symmetrically arranged on the left and right, and a cross bar horizontally arranged between the two vertical bars. The vertical bars are arranged perpendicular to the ground and fixed to the ground by fixed foot rods. The facing sides of the two vertical bars are provided with sliding rail grooves for adjusting the cross bar up and down, and the ends of the cross bar are fixed in the sliding rail grooves by cross bar rotation fixers.

[0011] A method for monitoring sediment concentration by fusion of acoustic and optical signal data, characterized in that it comprises the following steps: Step 1): The hydrophone is located at the bottom of the device and emits a 1.5MHz acoustic pulse vertically upward. The acoustic signal encounters the sediment particles in the water body, and part of the signal is backscattered to form Backscattered signal at time ; Step 2): Backscatter signal Perform Hilbert transform , take the envelope of the signal ,in, is the Hilbert transform, is the signal after Hilbert transform, is a constant, Backscattered signal The envelope; Step 3): Considering that there are many sediment particles in the water body, the scattered signal collected by the actual hydrophone is composed of signals with the same frequency but different amplitudes and phases. Therefore, the envelope signal in step 2 is sampled at the sampling time Integrate the above to get ,in, is the envelope signal At sampling time The integral on ; Step 4): Perform A / D conversion to obtain digital quantity ; Step 5): Digital quantity Multiple sampling, build The sample set sampled at the moment ; Step 6): For the sample set Taking the average value, we get , eliminating the instability caused by random quantities in sampling, where For the sample set The average value of Step 7): Take the square to get the hydrophone sediment concentration value Acoustic backscatter signal strength under conditions ,in, ; Step 8): Establish the relationship between the hydrophone sediment concentration value and the acoustic backscattering intensity: ,in It is an exponential relationship variable, which is determined based on the water body on-site comparative measurement information; Step 9): Establish a double constrained linear regression model ,in, represents the weighted value, represents the sediment concentration value of the hydrophone, represents the sediment concentration value of the turbidity meter, represents the sediment concentration value after fusion, represents the systematic error, which has a mean of 0 and a variance of Gaussian distribution of Step 10): The model is subject to dual constraints ,in, represents a linear constraint, represents the minimum variance of the system error without distortion, where: Represents the error covariance matrix, and the optimal weight is solved according to the principle of least squares. Since the error covariance matrix cannot be directly solved, the signal covariance matrix is ​​used Instead, the optimal weight is ; Step 11): The sediment concentration value after fusion is expressed as .

[0012] The beneficial effects of the present invention are: Since the wavelength of the optical signal is short, the light wave cannot penetrate the water body with a large particle concentration. The range of sediment concentration monitoring by the general optical method is small, while the sound wave has a better penetration effect in the water body. The present invention can effectively make up for the shortcomings of the light wave through the hydrophone; at the same time, the present invention uses the method of fusion of sound and light signal data to solve the problem of different response sensitivities of the sound and light signal to particles of different particle sizes, thereby realizing more stable and accurate sediment concentration monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention.

[0014] Figure 2 It is a schematic diagram of the structure of the integrated device of the turbidity meter and the hydrophone in the device of the present invention.

[0015] Figure 3 It is a flowchart of the method of the present invention.

[0016] List of reference numerals: 1-vertical pole, 2-horizontal pole rotation fixture, 3-fixed foot pole, 4-integrated device of turbidity meter and hydrophone, 5-horizontal pole, 6-turbidity meter, 7-hydrophone, 8-fixed bracket structure, 9-first cable routing structure, 10-second cable routing structure, 11-unified interface. DETAILED DESCRIPTION

[0017] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0018] like Figure 1 As shown, the present invention provides a sediment concentration monitoring device with acoustic and optical signal data fusion, including a frame and a turbidity meter and hydrophone integrated device 4, the turbidity meter and hydrophone integrated device is installed in the center of the frame, and its signal is emitted upward and perpendicular to the water surface, and the frame is used to adjust the immersion depth of the turbidity meter and hydrophone integrated device.

[0019] The frame includes two vertical bars 1 symmetrically arranged on the left and right, and a horizontal bar 5 arranged horizontally between the two vertical bars. The vertical bars are arranged perpendicular to the ground and fixed to the ground by a fixed foot bar 3. The two vertical bars have a slide rail groove for adjusting the horizontal bar up and down on the opposite sides. The ends of the horizontal bars are fixed in the slide rail groove by a horizontal bar rotation fixer 2. like Figure 2 As shown, the turbidity meter and hydrophone integrated device 4 includes a fixed bracket structure 8, and a turbidity meter 6 and a hydrophone 7 arranged on the fixed bracket structure. The turbidity meter and the hydrophone are fixed in the same plane, and a 5-core pluggable signal interface is reserved at the rear end. The two 5-core pluggable signal interfaces are respectively connected to a first cable and a second cable. The first cable and the second cable are respectively connected to a first cable routing structure 9 and a second cable routing structure 10 to form an external unified interface 11. The cable routing structure is used to route the cable.

[0020] In this embodiment, an anti-fouling wiper is integrated in front of the turbidity meter, and the working mode of the wiper is fixedly activated every time the power is turned on. The hydrophone is a transceiver-transmitter ultrasonic transducer with an operating frequency of 1.5 MHz.

[0021] In addition, the integrated device of the turbidity meter and the hydrophone also includes a data remote telemetry terminal, which is used to receive data output by the turbidity meter and the hydrophone, store the data locally, and then send it to the host computer through the wireless transmission module.

[0022] like Figure 3As shown, the present invention also provides a sediment concentration monitoring method using acoustic and optical signal data fusion, comprising the following steps: Step 1): The hydrophone is located at the bottom of the device and emits a 1.5MHz acoustic pulse vertically upward. The acoustic signal encounters the sediment particles in the water body, and part of the signal is backscattered to form Backscattered signal at time ; Step 2): Backscatter signal Perform Hilbert transform , take the envelope of the signal ,in, is the Hilbert transform, is the signal after Hilbert transform, is a constant, Backscattered signal The envelope; Step 3): Considering that there are many sediment particles in the water body, the scattered signal collected by the actual hydrophone is composed of signals with the same frequency but different amplitudes and phases. Therefore, the envelope signal in step 2 is sampled at the sampling time Integrate the above to get ,in, is the envelope signal At sampling time The integral on ; Step 4): Perform A / D conversion to obtain digital quantity ; Step 5): Digital quantity Multiple sampling, build The sample set sampled at the moment ; Step 6): For the sample set Taking the average value, we get , eliminating the instability caused by random quantities in sampling, where For the sample set The average value of Step 7): Take the square to get the hydrophone sediment concentration value Acoustic backscatter signal strength under conditions ,in, ; Step 8): Establish the relationship between the hydrophone sediment concentration value and the acoustic backscattering intensity: ,in It is an exponential relationship variable, which is determined based on the water body on-site comparative measurement information; Step 9): Establish a double constrained linear regression model ,in, represents the weighted value, represents the sediment concentration value of the hydrophone, represents the sediment concentration value of the turbidity meter, represents the sediment concentration value after fusion, represents the systematic error, which has a mean of 0 and a variance of Gaussian distribution of Step 10): The model is subject to dual constraints ,in, represents a linear constraint, represents the minimum variance of the system error without distortion, where: Represents the error covariance matrix, and the optimal weight is solved according to the principle of least squares. Since the error covariance matrix cannot be directly solved, the signal covariance matrix is ​​used Instead, the optimal weight is ; Step 11): The sediment concentration value after fusion is expressed as .

[0023] The present invention performs data fusion processing on the sediment concentration values ​​of the optical turbidity meter and the acoustic turbidity meter. Compared with the original single-means monitoring method, the present invention can effectively reduce the influence of the particle size of sediment particles in the water body on the sediment concentration monitoring and improve the stability and accuracy of monitoring.

[0024] The technical means disclosed in the scheme of the present invention are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical schemes composed of any combination of the above-mentioned technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also regarded as the protection scope of the present invention.

Claims

1. A sediment concentration monitoring device with acoustic and optical signal data fusion, characterized in that: The invention comprises a frame and an integrated device of a turbidity meter and a hydrophone. The integrated device of the turbidity meter and the hydrophone is installed in the center of the frame, and its signal emission faces upward and is perpendicular to the water surface. The frame is used to adjust the immersion depth of the integrated device of the turbidity meter and the hydrophone.

2. The device for monitoring sediment concentration by combining acoustic and optical signal data according to claim 1, characterized in that: The integrated device of turbidity meter and hydrophone includes a fixed support structure, and a turbidity meter and a hydrophone arranged on the fixed support structure. The turbidity meter and the hydrophone are fixed on the same plane, and a 5-core pluggable signal interface is reserved at the rear end. The two 5-core pluggable signal interfaces are respectively connected to a first cable and a second cable. The first cable and the second cable form a unified external interface through a first cable routing structure and a second cable routing structure respectively.

3. The device for monitoring sediment concentration by combining acoustic and optical signal data according to claim 2, characterized in that: An anti-fouling wiper is integrated in the front of the turbidity meter, and the working mode of the wiper is fixedly activated each time the power is turned on.

4. The device for monitoring sediment concentration by combining acoustic and optical signal data according to claim 2, characterized in that: The hydrophone is a transmitting and receiving ultrasonic transducer with an operating frequency of 1.5 MHz.

5. The device for monitoring sediment concentration by combining acoustic and optical signal data according to claim 2, characterized in that: The turbidity meter and hydrophone integrated device also includes a data remote telemetry terminal, which is used to receive data output by the turbidity meter and the hydrophone, store the data locally, and then send it to the host computer through the wireless transmission module.

6. The device for monitoring sediment concentration by combining acoustic and optical signal data according to claim 1, characterized in that: The frame includes two vertical bars symmetrically arranged on the left and right, and a cross bar horizontally arranged between the two vertical bars. The vertical bars are arranged perpendicular to the ground and fixed to the ground by fixed foot bars. The facing sides of the two vertical bars are provided with sliding rail grooves for adjusting the cross bar up and down. The ends of the cross bar are fixed in the sliding rail grooves by cross bar rotation fixers.

7. A method for monitoring sediment concentration by fusion of acoustic and optical signal data, characterized in that: The sediment concentration monitoring device according to any one of claims 1 to 6 is used, comprising the following steps: Step 1): The hydrophone is located at the bottom of the device and emits a 1.5MHz acoustic pulse vertically upward. The acoustic signal encounters the sediment particles in the water body, and part of the signal is backscattered to form Backscattered signal at time ; Step 2): Backscattered signal Perform Hilbert transform , take the envelope of the signal ,in, is the Hilbert transform, is the signal after Hilbert transform, is a constant, Backscattered signal The envelope of Step 3): Considering that there are many sediment particles in the water body, the scattered signal collected by the actual hydrophone is composed of signals with the same frequency but different amplitudes and phases. Therefore, the envelope signal in step 2 is sampled at the sampling time Integrate the above to get ,in, is the envelope signal At sampling time The integral on ; Step 4): Perform A / D conversion to obtain digital quantity ; Step 5): Digital quantity Multiple sampling, build The sample set sampled at the moment ; Step 6): For the sample set Taking the average value, we get , eliminating the instability caused by random quantities in sampling, where For the sample set The average value of Step 7): Take the square to get the hydrophone sediment concentration value Acoustic backscatter signal strength under conditions ,in, ; Step 8): Establish the relationship between the hydrophone sediment concentration value and the acoustic backscattering intensity: ,in It is an exponential relationship variable, which is determined based on the water body on-site comparative measurement information; Step 9): Establish a double constrained linear regression model ,in, represents the weighted value, represents the sediment concentration value of the hydrophone, represents the sediment concentration value of the turbidity meter, represents the sediment concentration value after fusion, represents the systematic error, which has a mean of 0 and a variance of Gaussian distribution of Step 10): The model is subject to dual constraints ,in, represents a linear constraint, represents the minimum variance of the system error without distortion, where: Represents the error covariance matrix, and the optimal weight is solved according to the principle of least squares. Since the error covariance matrix cannot be directly solved, the signal covariance matrix is ​​used Instead, the optimal weight is ; Step 11): The sediment concentration value after fusion is expressed as .

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