阅读说明：本技术 一种新型多频超声含沙量级配测量系统和方法 (Novel multi-frequency ultrasonic sand content grading measurement system and method ) 是由 杨文俊 景思雨 林海立 薛强 周建银 毕胜 宫平 陈越 孟震 李斌 于 2020-11-25 设计创作，主要内容包括：本发明提供一种新型多频超声含沙量级配测量系统和方法,属于环境原位监测技术领域,该系统主要包括超声测量探头和采集盒组成的采集系统、以及数据传输设备、用户端、标定装置,以用户端为载体的分析计算系统；超声测量探头是信号发出和接收设备,由压电复合晶片作为传感器；采样盒和用户端之间通过无线局域网连接进行数据传输。本发明具有更小的尺寸和测量盲区、较宽的泥沙浓度测量范围,采用新型材料制作传感器以提高探头的灵敏度并提高信噪比,同时,本发明所涉及的超声测量探头制作成本低,使用方便,精度较高。(The invention provides a novel multi-frequency ultrasonic sand content grading measurement system and a method, which belong to the technical field of environment in-situ monitoring, and mainly comprise an acquisition system consisting of an ultrasonic measurement probe and an acquisition box, data transmission equipment, a user side and a calibration device, and an analysis and calculation system taking the user side as a carrier; the ultrasonic measuring probe is a signal sending and receiving device, and a piezoelectric composite wafer is used as a sensor; and the sampling box and the user terminal are connected through a wireless local area network to carry out data transmission. The invention has smaller size and measuring blind area, wider sediment concentration measuring range, adopts novel materials to manufacture the sensor so as to improve the sensitivity of the probe and improve the signal-to-noise ratio, and simultaneously, the ultrasonic measuring probe related by the invention has low manufacturing cost, convenient use and higher precision.)

1. A novel multi-frequency ultrasonic sand content grading measurement system is characterized in that: the ultrasonic measurement probe comprises an ultrasonic measurement probe, a sampling box, data transmission equipment, a user terminal, a power supply and a calibration device; the ultrasonic measuring probe is used as underwater measuring equipment and is used for being fixed on a corresponding measuring carrier and placed into a water body to be measured, the ultrasonic measuring probe adopts a piezoelectric composite wafer as a sensor and adopts a self-generating and self-receiving working mode; the acquisition box is respectively connected with the ultrasonic measurement probe and the data transmission equipment, the acquisition box and the data transmission equipment are respectively connected with the power supply, and the data transmission equipment is in communication connection with the user side; the calibration device comprises a calibration barrel, drain pipes and a self-circulation water pump, wherein a small hole is reserved in an upper cover of the calibration barrel and used for adding water and sand and placing an ultrasonic measuring probe during measurement, the self-circulation water pump is connected with one ends of the two drain pipes, the other ends of the drain pipes extend into the calibration barrel, and an even concentration distribution field is formed in a water body of the calibration barrel through the water flow circulation effect when the self-circulation water pump is started.

2. The novel multi-frequency ultrasonic sand content grading measurement system of claim 1, wherein: the measuring carrier is various connecting rod devices observed indoors or a fish lead observed by a prototype.

3. The novel multi-frequency ultrasonic sand content grading measurement system of claim 1, wherein: the collection box comprises a signal sending unit and a signal collection unit. The signal sending unit provides the energy for exciting the ultrasonic waves for the ultrasonic measuring probe and controls the frequency for exciting the transmitting wafer; the signal acquisition unit is used for receiving the echo of the ultrasonic wave sent by the ultrasonic measurement probe, amplifying and converting the echo into a digital signal, and packaging the digital signal and transmitting the digital signal to the Ethernet bus interface.

4. A novel multi-frequency ultrasonic sand content grading measurement method, characterized by being carried out by using the system of any one of claims 1-3, the method comprising the steps of:

1) calibration was performed in the laboratory: the method comprises the following steps of (1) selecting organic glass to manufacture a calibration barrel, wherein the volume of the calibration barrel is known, connecting two water discharge pipes by using a self-circulation water pump, forming a uniform concentration distribution field in a water body of the calibration barrel through the circulation effect of water flow, reserving a small hole on an upper cover of the calibration barrel for adding water and sand and placing a probe during measurement, and injecting purified water into the calibration barrel to a sealing line;

2) adding the graded known natural sand with the calculated mass into a calibration barrel, blending into a sand-containing water body with known concentration, starting a self-circulation water pump and adjusting the flow, slowly circulating the water body in the whole calibration barrel until a relatively uniform and stable concentration field is formed, extending a pipette into a hole reserved for placing a probe, sampling at the position of the approximate center of the calibration barrel, calculating the actual concentration of a measuring point after drying and weighing, comparing with the known concentration, and verifying whether the concentration in the calibration barrel is uniform;

3) an ultrasonic measuring probe with known working frequency extends into the calibration barrel 8 from a reserved small hole and is fixed, a local area network of an acquisition box is connected to a user end, parameters are set to enable clear and complete waveforms to appear on a screen, and data acquisition is started;

4) after the data acquisition is finished and stored, adding natural sand into the calibration barrel again, increasing the sand concentration in the calibration barrel, repeating the step 3), and acquiring data under different concentrations;

5) emptying the water in the calibration barrel, cleaning, replacing the sediment of another particle size fraction, and measuring according to the steps 3) to 4) until the data acquisition of all the particle size fractions under different concentration conditions is completed;

6) performing time domain and spectrum analysis on all data to obtain a plurality of relation curves, corresponding concentration values, particle diameters and characteristic parameters of echo signals, establishing an inversion relation of sand content and gradation by using a backscattering method based on a Rayleigh scattering principle, and storing the inversion relation in a measurement system for later measurement;

7) when the sediment content of the natural river is measured, the ultrasonic measuring probe is fixed on the fish lead by the support and is placed in the river to be measured, the acquisition box is connected with the user side through the local area network, data acquisition and concentration calculation are carried out after the water flow is stable, and the data calculation is carried out by self in the system on the basis of the inversion relation obtained in the step 6) to obtain the final concentration and grading data.

5. The novel multi-frequency ultrasonic sand content grading measurement method of claim 4, wherein: the step 7) is specifically as follows: the method comprises the steps that a support is customized according to the size of an ultrasonic measuring probe and is fixed on a fish lead, a collection box, data transmission equipment and a power supply are placed in a reserved space in the fish lead, the fish lead carrying a measuring system is placed in water in a river section to be measured, the data transmission equipment is connected with a user side through a wireless local area network, the collection box and the data transmission equipment are powered by the power supply, and parameters are set on the user side for data collection and concentration calculation.

Technical Field

The invention relates to the technical field of environment in-situ monitoring, in particular to a novel multi-frequency ultrasonic sand content grading measurement system and method.

Background

The method for measuring the sediment parameter change in the natural river has important significance for understanding the sediment transport process, and is related to the design and maintenance of various hydraulic engineering. The water conservancy science theory depends on the calibration and verification of natural data to a great extent, however, the motion characteristics of river water and sand are complex, and the field synchronous real-time measurement of the river water and sand is very difficult. The existing measuring method for suspended load silt concentration and particle composition comprises the following steps: sampling analysis method, optical detection method, acoustic detection method, image observation method, B-ultrasonic imaging, remote sensing image interpretation analysis and the like.

Although the traditional field sampling and laboratory operation analysis mode has high measurement accuracy, the method is backward, and consumes time and labor; the optical detection method adopts an optical means to measure the sand-containing concentration and gradation in the natural river water flow, and can be roughly divided into a transmission method, a turbidity method, an optical backscattering method (OBS) and a Laser diffraction method (Laser diffraction), the scattering performance difference of silt particles with different matrixes, particle sizes and colors to light is large, real-time measurement is carried out by an optical turbidimeter and an LISTT series product and depends on an empirical relationship, and indoor experiments and outdoor experiments show that the LISST can reach 20-40% of gradation measurement error, the applicability and stability of the instrument can not meet the requirements of hydrological test specifications, and the Laser particle size analyzer can only carry out the gradation measurement in a laboratory; the picture method is to take pictures by advanced high-pixel and high-precision micro-camera equipment, can clearly reflect the scale characteristics of particles, and can obtain the concentration by calculation, but the instrument equipment has structural defects, for example, a sand-containing water body needs to enter a measuring box to be irradiated by laser, and an ideal result is difficult to obtain.

The acoustic detection method measures suspended sediment information by using the characteristics of scattering, attenuation and the like of ultrasonic waves in a medium, and the ultrasonic measurement equipment has the advantages of energy concentration, no interference to a flow field, rapidness, real time and the like. Based on the sound attenuation method, Sumingxu et al (CN104849183A) propose a method for measuring the concentration and average particle size of bubbles or particles in a liquid by sound attenuation spectroscopy, which can be used in the case of two mixed particulate matters, and can be used for laboratory and field measurements. And then, an improved method (CN104833619A) for measuring the particle size and concentration of solid particles in a gas or liquid medium based on the ultrasonic attenuation spectrum principle is provided, the average particle size and concentration of the particles are obtained by solving an objective function through the ultrasonic attenuation spectrum of the particles in a measuring region, calculating the noise elimination coefficient and calculating the scattering exit angle of ultrasonic photons, the method is limited by the bandwidth, the range of the detected particle size is 20-100 mu m, and the method is only suitable for fine particle measurement. The inverse relationship between particle concentration and signal intensity is obtained by calibration of devices such as ADV and ADCP based on the back scattering principle, the real-time measurement capability is not provided, the distance from a probe to a detection body is long, and the attenuation of signals on a propagation path is too large, so that useful information is difficult to obtain.

The above-mentioned apparatus has obvious limitations for the measurement of the particle motion parameters: one is to adapt only to very low concentrations (sparse particles); secondly, the device is mostly limited to off-line measurement, the structure of the device is complex, the use is inconvenient, and the device which can be applied to on-site real-time measurement is fresh; thirdly, most devices cannot realize simultaneous measurement of concentration and gradation. Compared with foreign countries, the development of the original research and development of suspended load silt content and gradation measuring instruments in China is relatively lagged, and the measuring range is very limited.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a novel multi-frequency ultrasonic sand content grading measurement system and method, which aim to solve the defects of the existing particle concentration and grading measurement technology and the limitation that online real-time measurement cannot be carried out.

A novel multi-frequency ultrasonic sand content grading measurement system comprises an ultrasonic measurement probe, a sampling box, data transmission equipment, a user side, a power supply and a calibration device; the ultrasonic measuring probe is used as underwater measuring equipment and is used for being fixed on a corresponding measuring carrier and placed into a water body to be measured, the ultrasonic measuring probe adopts a piezoelectric composite wafer as a sensor and adopts a self-generating and self-receiving working mode; the acquisition box is respectively connected with the ultrasonic measurement probe and the data transmission equipment, the acquisition box and the data transmission equipment are respectively connected with the power supply, and the data transmission equipment is in communication connection with the user side; the calibration device comprises a calibration barrel, drain pipes and a self-circulation water pump, wherein a small hole is reserved in an upper cover of the calibration barrel and used for adding water and sand and placing an ultrasonic measuring probe during measurement, the self-circulation water pump is connected with one ends of the two drain pipes, the other ends of the drain pipes extend into the calibration barrel, and an even concentration distribution field is formed in a water body of the calibration barrel through the water flow circulation effect when the self-circulation water pump is started.

Further, the measuring carrier is various connecting rod devices observed indoors or a fish lead observed by a prototype.

Further, the collection box comprises a signal sending unit and a signal collection unit. The signal sending unit provides the energy for exciting the ultrasonic waves for the ultrasonic measuring probe and controls the frequency for exciting the transmitting wafer; the signal acquisition unit is used for receiving the echo of the ultrasonic wave sent by the ultrasonic measurement probe, amplifying and converting the echo into a digital signal, and packaging the digital signal and transmitting the digital signal to the Ethernet bus interface.

A novel multi-frequency ultrasonic sand content grading measurement method is characterized by being carried out by adopting the system, and comprises the following steps:

1) calibration was performed in the laboratory: the method comprises the following steps of (1) selecting organic glass to manufacture a calibration barrel, wherein the volume of the calibration barrel is known, connecting two water discharge pipes by using a self-circulation water pump, forming a uniform concentration distribution field in a water body of the calibration barrel through the circulation effect of water flow, reserving a small hole on an upper cover of the calibration barrel for adding water and sand and placing a probe during measurement, and injecting purified water into the calibration barrel to a sealing line;

2) adding the graded known natural sand with the calculated mass into a calibration barrel, blending into a sand-containing water body with known concentration, starting a self-circulation water pump and adjusting the flow, slowly circulating the water body in the whole calibration barrel until a relatively uniform and stable concentration field is formed, extending a pipette into a hole reserved for placing a probe, sampling at the position of the approximate center of the calibration barrel, calculating the actual concentration of a measuring point after drying and weighing, comparing with the known concentration, and verifying whether the concentration in the calibration barrel is uniform;

3) an ultrasonic measuring probe with known working frequency extends into the calibration barrel 8 from a reserved small hole and is fixed, a local area network of an acquisition box is connected to a user end, parameters are set to enable clear and complete waveforms to appear on a screen, and data acquisition is started;

4) after the data acquisition is finished and stored, adding natural sand into the calibration barrel again, increasing the sand concentration in the calibration barrel, repeating the step 3), and acquiring data under different concentrations;

5) emptying the water in the calibration barrel, cleaning, replacing the sediment of another particle size fraction, and measuring according to the steps 3) to 4) until the data acquisition of all the particle size fractions under different concentration conditions is completed;

6) performing time domain and spectrum analysis on all data to obtain a plurality of relation curves, corresponding concentration values, particle diameters and characteristic parameters of echo signals, establishing an inversion relation of sand content and gradation by using a backscattering method based on a Rayleigh scattering principle, and storing the inversion relation in a measurement system for later measurement;

7) when the sediment content of the natural river is measured, the ultrasonic measuring probe is fixed on the fish lead by the support and is placed in the river to be measured, the acquisition box is connected with the user side through the local area network, data acquisition and concentration calculation are carried out after the water flow is stable, and the data calculation is carried out by self in the system on the basis of the inversion relation obtained in the step 6) to obtain the final concentration and grading data.

Further, the step 7) is specifically as follows: the method comprises the steps that a support is customized according to the size of an ultrasonic measuring probe and is fixed on a fish lead, a collection box, data transmission equipment and a power supply are placed in a reserved space in the fish lead, the fish lead carrying a measuring system is placed in water in a river section to be measured, the data transmission equipment is connected with a user side through a wireless local area network, the collection box and the data transmission equipment are powered by the power supply, and parameters are set on the user side for data collection and concentration calculation.

The invention has the characteristics and beneficial effects that: compared with the prior art, the sensor adopts the piezoelectric composite material as the sensor of the probe, has the characteristics of high sensitivity, large bandwidth and low acoustic impedance, has better coupling condition with surrounding media, is suitable for high-frequency working environment, makes up the defect that reliable data cannot be obtained due to overlarge acoustic attenuation under the condition of high concentration, and greatly increases the measurable concentration range; the probe processes the echo signal in calculation from time domain analysis and spectrum analysis, can simultaneously measure the concentration and the particle size distribution of the silt, improves the measurement accuracy, and overcomes the difficulty of grading field measurement; the calibration system adopts the water flow self-circulation effect to form an even concentration field, and the water-sand mixing effect is better.

Drawings

FIG. 1 is a schematic structural diagram of one embodiment of the multi-frequency ultrasonic sand content grading measurement system of the present invention;

FIG. 2 is a schematic structural diagram of an indoor calibration device in an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a field in-situ measurement apparatus according to an embodiment of the present invention.

The reference numerals in the figures are as follows:

1-ultrasonic measuring probe, 2-collecting box, 3-data transmission equipment, 4-user terminal, 5-power supply, 6-water body to be measured, 7-echo signal, 8-calibration barrel, 9-drain pipe, 10-self-circulation water pump, 11-fish lead and 12-bracket.

Detailed Description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments, but not all embodiments, of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Referring to fig. 1, an embodiment of the present invention provides a novel multi-frequency ultrasonic sand content grading measurement system, which includes an ultrasonic measurement probe 1, a sample box 2, a data transmission device 3 (e.g., a router), a user terminal 4 (e.g., a computer), and a power supply 5.

The ultrasonic measuring probe 1 is used as an underwater measuring device, needs to be fixed on a corresponding carrier and put into a water body to be measured, adopts a piezoelectric composite wafer as a sensor, and adopts a self-generating and self-receiving working mode; the ultrasonic measurement probe 1 is light in structure, can design a corresponding probe external structure according to different measurement environments, is suitable for grading measurement of sand content of indoor and outdoor water bodies, and can be fixed on various measurement carriers, such as various connecting rod devices for indoor observation (shown in figure 2) or a fish lead 11 for prototype observation (shown in figure 3) and the like.

The acquisition box 2 is respectively connected with the ultrasonic measurement probe 1 and the data transmission device 3, and the data transmission device 3 is in communication connection (for example, through a wireless local area network) with the user terminal 4; the collecting box 2 and the data transmission device 3 are respectively connected with a power supply 5, and the power supply 5 is used for supplying working voltage to the collecting box 2 and the data transmission device 3. The user terminal 4 is provided with an interface and a calculation program for a user.

The acquisition box 2 includes a signal transmission unit and a signal acquisition unit. The signal sending unit provides the energy for exciting the ultrasonic waves for the ultrasonic measuring probe 1 and controls the frequency for exciting the transmitting wafer; the signal acquisition unit is used for receiving the echo of the ultrasonic wave sent by the ultrasonic measurement probe 1, amplifying and converting the echo into a digital signal, packaging the digital signal, transmitting the digital signal to the Ethernet bus interface, and transmitting the digital signal to the user terminal 4 through the data transmission equipment 3.

As shown in fig. 2, the embodiment of the present invention further includes a calibration device used in cooperation, where the calibration device includes a calibration barrel 8, a drain pipe 9, and a self-circulation water pump 10; the calibration barrel 8 is used for injecting pure water and natural sand, a small hole is reserved on an upper cover of the calibration barrel 8 and used for adding water and sand and placing the ultrasonic measuring probe 1 during measurement; the self-circulation water pump 10 is connected with one ends of the two drain pipes 9, the other ends of the drain pipes 9 extend into the calibration barrel 8, and an even concentration distribution field is formed in the water body of the calibration barrel 8 through the water circulation effect when the self-circulation water pump 10 is started.

The embodiment of the invention also provides a novel multi-frequency ultrasonic sand content grading measurement method, which is carried out by adopting the system, and the method specifically comprises the following steps (in combination with the reference of fig. 2 and 3):

1) calibration was performed in the laboratory: the calibration barrel 8 is made of organic glass, the volume of the calibration barrel 8 is known, a self-circulation water pump 10 is connected with two water discharge pipes 9, a uniform concentration distribution field is formed in a water body of the calibration barrel 8 through the circulation effect of water flow, a small hole is reserved in an upper cover of the calibration barrel 8 and used for adding water and sand and placing a probe during measurement, and purified water is injected into the calibration barrel 8 to a sealing line;

2) adding the graded known natural sand with the calculated quality (the natural sand is collected from a river section to be detected and is divided into a plurality of particle size grades through screening) into the calibration barrel 8, preparing the natural sand into a sand-containing water body with known concentration, starting the self-circulation water pump 10 and adjusting the flow, slowly circulating the water body in the whole calibration barrel 8 until a relatively uniform and stable concentration field is formed, extending a pipette (or an injector) into a hole reserved for placing a probe, sampling at the position of the approximate center of the calibration barrel 8, calculating the actual concentration of a measuring point after drying and weighing, and comparing the actual concentration with the known concentration to verify whether the concentration of the calibration barrel 8 is uniform or not;

3) an ultrasonic measuring probe 1 with known working frequency extends into a calibration barrel 8 from a reserved small hole and is fixed, a local area network of an acquisition box 2 is connected to a user terminal 4, parameters are set to enable clear and complete waveforms to appear on a screen, and data acquisition is started;

4) after the data acquisition is finished and stored, adding natural sand into the calibration barrel 8 again, increasing the sand concentration in the calibration barrel, repeating the step 3), and acquiring data under different concentrations;

5) emptying the water in the calibration barrel 8, cleaning, replacing the sediment of another particle size fraction, and measuring according to the steps 3) to 4) until the data acquisition of all the particle size fractions under different concentration conditions is completed;

6) performing time domain and spectrum analysis on all data to obtain a plurality of relation curves, corresponding concentration values, particle diameters and characteristic parameters of echo signals, establishing an inversion relation of sand content and gradation by using a backscattering method based on a Rayleigh scattering principle, and storing the inversion relation in a measurement system for later measurement;

7) when measuring the sand content of the natural river, as shown in fig. 3, the ultrasonic measuring probe 1 is fixed on a fish lead 11 by a bracket 12, the fish lead is placed in the river to be measured, the acquisition box 2 is connected with the user terminal 4 through a local area network, data acquisition and concentration calculation are performed after the water flow is stable, and the data calculation is performed by self in the system based on the inversion relation obtained in the step 6) to obtain final concentration and grading data.

Specifically, as shown in fig. 3, during field operation, the sand concentration in a natural river is measured, a fish lead 11 is selected as a carrier of a measuring system, a bracket 12 is customized according to the size of the ultrasonic measuring probe 1 and is fixed on the fish lead 11, and a reserved space inside the fish lead 11 is used for placing the acquisition box 2, the data transmission equipment 3 and the power supply 5. The fish 11 with the measuring system is put into water in the river reach to be measured, and the data transmission device 3 is connected with the user terminal 4 through the wireless local area network. The acquisition box 2 and the data transmission device 3 are powered by a power supply 5, and after the circuit is connected, parameters are set on the user terminal 4 to perform data acquisition and concentration calculation.

8) In order to acquire data of different measuring points, the position of the fish lead 11 in the river is changed, and then the measurement is carried out again according to the steps until the data acquisition in the whole river reach is completed.

The invention is mainly based on the Rayleigh scattering principle, processes the acoustic signals of particles in a measuring area through time domain analysis and spectral analysis, and has the main innovation of indoor calibration of an ultrasonic measuring probe device and in-situ real-time measurement of the concentration of silt in a natural river. The object of the invention is the concentration of suspended and dispersed particles in liquid, which can be silt in a river or a mixed liquid of particles and liquid in a laboratory.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.