CA3010122C - Collecting apparatus, system and method for gravel transport pressure and transport audio - Google Patents
Collecting apparatus, system and method for gravel transport pressure and transport audio Download PDFInfo
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- CA3010122C CA3010122C CA3010122A CA3010122A CA3010122C CA 3010122 C CA3010122 C CA 3010122C CA 3010122 A CA3010122 A CA 3010122A CA 3010122 A CA3010122 A CA 3010122A CA 3010122 C CA3010122 C CA 3010122C
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M10/00—Hydrodynamic testing; Arrangements in or on ship-testing tanks or water tunnels
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
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Abstract
The present invention discloses a collecting apparatus, system, and method for gravel transport pressure and transport audio. The collecting apparatus includes: an upper baffle, a lower baffle and a protective cover provided between two baffles for preventing the impact of gravels and the sediment water flow; the upper baffle, the lower baffle and the protective cover enclose a cavity; a sound pickup device for collecting the gravel transport audio and a plurality of strain sensors for collecting the gravel pressure received by the upper baffle and the lower baffle during the transporting process are fixedly mounted inside the cavity; the sound pickup device is fixedly mounted on the upper baffle or the lower baffle, and the strain sensor is fixedly mounted between the upper baffle and the lower baffle. The collecting system includes a plurality of collecting apparatus arranged on the river bed, a base station provided on a bank for preprocessing the collected information, and a server communicatively connected with the base station; the collecting apparatus is communicatively connected with the base station. The collection apparatus and collecting system mentioned above can accurately monitor the gravel movement for a long period of time.
Description
COLLECTING APPARATUS, SYSTEM AND METHOD FOR GRAVEL
TRANSPORT PRESSURE AND TRANSPORT AUDIO
TECHNICAL FIELD
The present invention relates to the field of channel observation, and in particular, to a collecting apparatus, system and method for gravel transport pressure and transport audio.
BACKGROUND TECHNOLOGY
The condition of the channel in the reservoir area has been greatly improved after the operation of the Three Gorges Reservoir impoundment, but it still cannot fully adapt to the current development of shipping. It is believed that the shoal impediments to navigation in the fluctuating backwater area are mainly caused by the erosion-deposition variation of the gravel according to many years of observation and analysis of the channel sediment prototype. At present, due to the limitations of observation equipment and observation techniques, the real-time movement characteristics of prototype gravel transport could not be effectively obtained, and therefore it is not clear to understand the shoal erosion-deposition regularity of the gravel in the fluctuating backwater area.
There are two main types of existing bed load observation techniques: direct measurements and indirect methods. The direct measurement method mainly measures the bed load directly by means of samplers and apparatuses of various sizes and structures, and the pressure-difference sampler and the bedload traps are used more often. The indirect measurement method mainly calculates the sediment transport rate of the bed load indirectly by measuring the parameters related to the movement of the bed load based on various physical principles, which mainly includes the tracer method, the optical systems and the acoustic method, etc.
Due to the randomness of time and space of the movement of the bed load, it is unable to capture accurate information by sampling with sampler. Moreover, the sampler interferes with the flow conditions around the apparatus during the sampling process, and the high-speed moving bed load particles hit the sampler, causing certain damages to the sampler, and the high-speed flow condition is unsuitable for the shipboard operations. The bedload traps can only estimate the gravel transport amount after the flood, and cannot obtain the dynamic changes of the quality of the bed load over time. The tracer method can only study a limited range of the particle size no matter which of the radioactive particles, radio tracking technology, or magnetic tracer particles are used, and since the particles buried each other in the process of movement, the recovery rate is low. Further, some of the particles may cause certain pollution to the environment, and the cost, as well as the test cost, is high. The optical measurement method mainly refers to observing the movement of underwater bed load through high-definition camera, which has a higher requirement for the water quality and sediment concentration of the observation environment. Thus, necessary protections, as well as effective lighting measures at the same time, must be given to the equipment. An ultrasonic topographic apparatus is greatly affected by resolution, timeliness, flow condition and sediment concentration, thus the observation results are difficult to meet the requirements.
Acoustic method can be used to measure the transport amount of the bed load in both low-speed and high-speed flow conditions. At present, many people have used the acoustic method to perform the observation of the bed load of rivers. For example, the Chinese Patent Application No. 201510915272.9 discloses a collecting system, a collecting apparatus and a collecting method for the sound of gravel transport observation, in which the technical features of the method for collecting are as follows: placing a hydrophone, arranging a plurality of hydrophones along the length and width of the river bed, and arranging the hydrophones fixedly in the river water; arranging acoustic generators one by one corresponding to the hydrophones, arranging each of the acoustic generators on the bed of the river bed and below the corresponding one of the hydrophones. It is possible to collect and record the gravel movement at multiple points and in multiple areas. However, there is still room for improvement in this solution. For example, the number of gravels and the number of the distribution layer of the gravels in the water flow will increase dramatically when the water flow velocity is too fast. At this time, the accuracy of the acoustic measurement is very poor.
SUMMARY OF THE INVENTION
In view of the above defects in the prior art, the technical problem aimed to be solved by the present invention is to provide a collecting apparatus, system and method for gravel transport pressure and transport audio that can accurately monitor the gravel movement for a long period of time, regardless of whether the water flow velocity is fast or slow, or the gravel transport amount is large or small. The problem of inaccurate detection for gravel movements in the case that the water flow velocity is fast or the number of the gravels is too much is solved.
To solve the above technical problems, the technical solution adopted by the present invention is as below:
A collecting apparatus for gravel transport pressure and transport audio is provided. The apparatus includes an upper baffle, a lower baffle and a protective cover provided between two baffles for preventing the impact of gravels and the sediment water flow; the upper baffle, the
TRANSPORT PRESSURE AND TRANSPORT AUDIO
TECHNICAL FIELD
The present invention relates to the field of channel observation, and in particular, to a collecting apparatus, system and method for gravel transport pressure and transport audio.
BACKGROUND TECHNOLOGY
The condition of the channel in the reservoir area has been greatly improved after the operation of the Three Gorges Reservoir impoundment, but it still cannot fully adapt to the current development of shipping. It is believed that the shoal impediments to navigation in the fluctuating backwater area are mainly caused by the erosion-deposition variation of the gravel according to many years of observation and analysis of the channel sediment prototype. At present, due to the limitations of observation equipment and observation techniques, the real-time movement characteristics of prototype gravel transport could not be effectively obtained, and therefore it is not clear to understand the shoal erosion-deposition regularity of the gravel in the fluctuating backwater area.
There are two main types of existing bed load observation techniques: direct measurements and indirect methods. The direct measurement method mainly measures the bed load directly by means of samplers and apparatuses of various sizes and structures, and the pressure-difference sampler and the bedload traps are used more often. The indirect measurement method mainly calculates the sediment transport rate of the bed load indirectly by measuring the parameters related to the movement of the bed load based on various physical principles, which mainly includes the tracer method, the optical systems and the acoustic method, etc.
Due to the randomness of time and space of the movement of the bed load, it is unable to capture accurate information by sampling with sampler. Moreover, the sampler interferes with the flow conditions around the apparatus during the sampling process, and the high-speed moving bed load particles hit the sampler, causing certain damages to the sampler, and the high-speed flow condition is unsuitable for the shipboard operations. The bedload traps can only estimate the gravel transport amount after the flood, and cannot obtain the dynamic changes of the quality of the bed load over time. The tracer method can only study a limited range of the particle size no matter which of the radioactive particles, radio tracking technology, or magnetic tracer particles are used, and since the particles buried each other in the process of movement, the recovery rate is low. Further, some of the particles may cause certain pollution to the environment, and the cost, as well as the test cost, is high. The optical measurement method mainly refers to observing the movement of underwater bed load through high-definition camera, which has a higher requirement for the water quality and sediment concentration of the observation environment. Thus, necessary protections, as well as effective lighting measures at the same time, must be given to the equipment. An ultrasonic topographic apparatus is greatly affected by resolution, timeliness, flow condition and sediment concentration, thus the observation results are difficult to meet the requirements.
Acoustic method can be used to measure the transport amount of the bed load in both low-speed and high-speed flow conditions. At present, many people have used the acoustic method to perform the observation of the bed load of rivers. For example, the Chinese Patent Application No. 201510915272.9 discloses a collecting system, a collecting apparatus and a collecting method for the sound of gravel transport observation, in which the technical features of the method for collecting are as follows: placing a hydrophone, arranging a plurality of hydrophones along the length and width of the river bed, and arranging the hydrophones fixedly in the river water; arranging acoustic generators one by one corresponding to the hydrophones, arranging each of the acoustic generators on the bed of the river bed and below the corresponding one of the hydrophones. It is possible to collect and record the gravel movement at multiple points and in multiple areas. However, there is still room for improvement in this solution. For example, the number of gravels and the number of the distribution layer of the gravels in the water flow will increase dramatically when the water flow velocity is too fast. At this time, the accuracy of the acoustic measurement is very poor.
SUMMARY OF THE INVENTION
In view of the above defects in the prior art, the technical problem aimed to be solved by the present invention is to provide a collecting apparatus, system and method for gravel transport pressure and transport audio that can accurately monitor the gravel movement for a long period of time, regardless of whether the water flow velocity is fast or slow, or the gravel transport amount is large or small. The problem of inaccurate detection for gravel movements in the case that the water flow velocity is fast or the number of the gravels is too much is solved.
To solve the above technical problems, the technical solution adopted by the present invention is as below:
A collecting apparatus for gravel transport pressure and transport audio is provided. The apparatus includes an upper baffle, a lower baffle and a protective cover provided between two baffles for preventing the impact of gravels and the sediment water flow; the upper baffle, the
2 lower baffle and the protective cover enclose a cavity; a sound pickup device for collecting the gravel transport audio and a plurality of strain sensors for collecting the gravel pressure received by the upper baffle and the lower baffle during the transporting process are fixedly mounted inside the cavity; the sound pickup device is fixedly mounted on the upper baffle or the lower baffle, and the strain sensor is fixedly mounted between the upper baffle and the lower baffle.
In the present application, the collecting apparatus is arranged on the bottom surface of the river; the upper baffle, the lower baffle and the protective cover are all made of steel plates, and are fixedly connected to each other by means of bolts. The protective cover may prevent the impact of gravel and sediment water flow and protect the security of the electronic device inside the cavity; thus the impact of underwater environment is reduced and the lifetime of the electronic equipment is increased. At the same time, the subsequent maintenance of the devices may also be facilitated. The sound pickup device is provided inside the cavity for collecting the sound information generated from gravel transport above the collecting apparatus. The strain sensor is fixedly mounted between the upper baffle and the lower baffle for measuring the pressure information of the gravels acted on the upper baffle and the lower baffle during the transporting process of the gravels from above the apparatus; and the river bottom gravel transport movement amount and the gravel transport movement trajectory are determined by analyzing the collected audio information and pressure information.
Further and preferably, the sound pickup device is fixedly mounted in the middle area of the upper baffle. Since there is a certain distance between the upper baffle and the lower baffle, and the gravels pass above the collecting apparatus, it is more advantageous to mount the sound pickup device on the middle of the upper baffle inner side than on the lower baffle, so that a louder volume of the audio may be received, and thus the reception efficiency and reception accuracy of the audio may be improved.
Further and preferably, the upper sensing point of the strain sensor is fixedly attached to an upper baffle through an elastic element, and a support rod along a vertical direction and a columnar base are provided between a lower sensing point of the strain sensor and the lower baffle; a top end of the support rod is fixedly attached to the lower sensing point of the strain sensor, and a bottom end of the support rod is fixedly conn:cted to a top of the base; an inner side of the lower baffle corresponding to a position of the base is recessed inward to provide a receiving cavity for receiving the base, and a bottom of the base is protruded into the receiving cavity and is attached to the lower baffle.
In the collecting apparatus for gravel transport pressure and transport audio mentioned above, the detection principle of the strain sensor is as follows: sensing elements are fixedly
In the present application, the collecting apparatus is arranged on the bottom surface of the river; the upper baffle, the lower baffle and the protective cover are all made of steel plates, and are fixedly connected to each other by means of bolts. The protective cover may prevent the impact of gravel and sediment water flow and protect the security of the electronic device inside the cavity; thus the impact of underwater environment is reduced and the lifetime of the electronic equipment is increased. At the same time, the subsequent maintenance of the devices may also be facilitated. The sound pickup device is provided inside the cavity for collecting the sound information generated from gravel transport above the collecting apparatus. The strain sensor is fixedly mounted between the upper baffle and the lower baffle for measuring the pressure information of the gravels acted on the upper baffle and the lower baffle during the transporting process of the gravels from above the apparatus; and the river bottom gravel transport movement amount and the gravel transport movement trajectory are determined by analyzing the collected audio information and pressure information.
Further and preferably, the sound pickup device is fixedly mounted in the middle area of the upper baffle. Since there is a certain distance between the upper baffle and the lower baffle, and the gravels pass above the collecting apparatus, it is more advantageous to mount the sound pickup device on the middle of the upper baffle inner side than on the lower baffle, so that a louder volume of the audio may be received, and thus the reception efficiency and reception accuracy of the audio may be improved.
Further and preferably, the upper sensing point of the strain sensor is fixedly attached to an upper baffle through an elastic element, and a support rod along a vertical direction and a columnar base are provided between a lower sensing point of the strain sensor and the lower baffle; a top end of the support rod is fixedly attached to the lower sensing point of the strain sensor, and a bottom end of the support rod is fixedly conn:cted to a top of the base; an inner side of the lower baffle corresponding to a position of the base is recessed inward to provide a receiving cavity for receiving the base, and a bottom of the base is protruded into the receiving cavity and is attached to the lower baffle.
In the collecting apparatus for gravel transport pressure and transport audio mentioned above, the detection principle of the strain sensor is as follows: sensing elements are fixedly
3 _ provided between the upper baffle and the lower baffle, and the sensing element may be mechanically deformed along with the upper baffle or the lower baffle; the strain sheet of the strain sensor is pasted on the sensing element and the strain sheet may be mechanically deformed along with the sensing piece; the strain sheet is made of metal, and the resistance of the metal changes with the degree of deformation; as the resistance changes, the corresponding detected voltage also changes, and the change of the corresponding received pressure may be determined through the detected voltage. The elastic element is provided between the upper sensing point of the strain sensor and the upper baffle, so that the rigid connection between the upper sensor point of strain sensor and upper baffle may be avoided, and the sensitivity of the strain sensor to pressure change may be ensured at the same time. The inner side of the lower baffle corresponding to the position of the base is recessed inward to provide a receiving cavity for receiving the base, and the bottom of the base is protruded into the receiving cavity and is attached to the lower baffle. The above configuration faciliWtes the installation and removal of the entire component, while preventing the base from being unstable and easily slipping.
Further and preferably, the protective cover is provided with a round hole for placing a cable. The cable includes data lines and power lines. A waterproof ring may be provided at the round hole, and the protective cover and the waterproof ring are used in combination to prevent the river water from entering into the cavity.
Further and preferably, the collecting apparatus further includes a fixing mean for fixing the collecting apparatus on a river bed, and the fixing mean is fixedly mounted at a bottom of the lower baffle.
By fixing the collecting apparatus of the present application to the bottom of the river, the gravel transport movement amount and the gravel transport movement trajectory at or near the site can be collected at a fixed point. In practical use, a plurality of collecting apparatus may be arranged equidistantly at the bottom of the river. Fixing the collecting apparatus is also beneficial to improve the accuracy of gravel transport analysis.
A collecting system for gravel transport pressure and transport audio is provided. The system includes a plurality of collecting apparatus arranged on the river bed, a base station provided on a bank for preprocessing the collected information, and a server communicatively connected with the base station; the collecting apparatus is the collecting apparatus for gravel transport pressure and transport audio; the collecting apparatus is communicatively connected with the base station.
In the collecting system for gravel transport pressure and transport audio mentioned above, a plurality of collecting apparatuses are distributed uniformly at the bottom of the river and are
Further and preferably, the protective cover is provided with a round hole for placing a cable. The cable includes data lines and power lines. A waterproof ring may be provided at the round hole, and the protective cover and the waterproof ring are used in combination to prevent the river water from entering into the cavity.
Further and preferably, the collecting apparatus further includes a fixing mean for fixing the collecting apparatus on a river bed, and the fixing mean is fixedly mounted at a bottom of the lower baffle.
By fixing the collecting apparatus of the present application to the bottom of the river, the gravel transport movement amount and the gravel transport movement trajectory at or near the site can be collected at a fixed point. In practical use, a plurality of collecting apparatus may be arranged equidistantly at the bottom of the river. Fixing the collecting apparatus is also beneficial to improve the accuracy of gravel transport analysis.
A collecting system for gravel transport pressure and transport audio is provided. The system includes a plurality of collecting apparatus arranged on the river bed, a base station provided on a bank for preprocessing the collected information, and a server communicatively connected with the base station; the collecting apparatus is the collecting apparatus for gravel transport pressure and transport audio; the collecting apparatus is communicatively connected with the base station.
In the collecting system for gravel transport pressure and transport audio mentioned above, a plurality of collecting apparatuses are distributed uniformly at the bottom of the river and are
4 used to detect the gravel transport condition at or around the arranged point.
The collecting apparatus may be recycled periodically without fear of burying. The base station is provided on the river bank. One base station may supervise the collected information of a plurality of collecting apparatuses. The preprocessing of the collected information by the base station mainly refers to preprocess the sound information, including filtering and enhancement or other processing methods, and the base station transmits the preprocessed collected information to the server. The base station plays a role of transmitting and preprocessing, so that the burden of data transmission is reduced and the utilization efficiency of the collected information is improved.
By means of the server, the gravel transport condition may be monitored remotely in real time, and the spatial distribution of gravel movement may be observed.
Further and preferably, the collecting system for gravel transport pressure and transport audio is connected with the base station through a cable, and the base station and the server are connected through wireless communications.
In the collecting system for gravel transport pressure and transport audio mentioned above, the audio information and pressure information collected by the collecting apparatus are transmitted to the base station on the bank through the cable. Although the transmission method may also be wireless transmission, considering the complex underwater environment, weak wireless signal, and limited transmission distance, cable transmission is selected. With cable transmission, the information is more stable and the transmission distance is longer. After testing, the transmission distance of the cable transmission may reach 3000 meters, and the cable transmission may be usable in a wide range. One base station may manage the collecting apparatuses that are within a large range.
Further and preferably, the cables are arranged to cling to the river bed in a straight line. In daily life, there are often many ships, as well as floating debris in the river, and also many aquatic plants, as well as fish and shrimp swimming back and forth in the river. If the cables are floating on the river or in the river, the cables are easily entangled with ships, debris, or aquatic plants, which may easily cause safety accidents. Therefore, the cables are arranged to cling to the river bed so that the above situation may be avoided. In addition, the impact of the water flow at the bottom of the river is relatively small, which can protect the cable to some extent. Arranging the cables in a straight line on the river bed, it is also an objective to avoid the cables entangling with debris because of too much cables, and the cost may also be reduced.
A collecting method for gravel transport pressure and transport audio includes:
a step of arranging a collecting apparatus: arranging a plurality of collecting apparatus crossly and equidistantly respectively along a length and a width direction of the river bed; fixing the collecting apparatus on a river bed through a fixing mean; and a cable between the collecting apparatus and a base station on a bank being arranged to cling to the river bed and in a straight line;
a step of collecting information: collecting the gravel transport audio information by a sound pickup device in real time; collecting pressure information of the gravels received by an upper baffle and a lower baffle by a strain sensor in real time; and transmitting the collected audio information and the pressure information to the base station through the cable;
preprocessing the collected audio information and pressure information in the base station, and transmitting the preprocessed audio information and pressure information to a server;
a step of analyzing information: preprocessing the collected audio information and pressure information in the base station, and transmitting the preprocessed audio information and pressure information to a server; analyzing and comparing the collected audio information and pressure information by the server; when a volume decibel corresponding to the audio information is smaller than a volume preset value, or a pressure value corresponding to the pressure information is smaller than a pressure preset value, determining a gravel transport movement amount and a gravel transport movement trajectory by analyzing the volume decibel corresponding to the audio information; and when the volume decibel corresponding to the audio information is greater than or equal to the volume preset value, or the pressure value corresponding to the pressure information is greater than or equal to the pressure preset value, determining the gravel transport movement amount and the gravel transport movement trajectory by analyzing the pressure value corresponding to the pressure information.
Further and preferably, the gravel transport audio information is identified from the audio information by analyzing a characteristic parameter of the audio information;
the characteristic parameters include a peak frequency of the audio information, a pitch frequency of the audio information, and an energy distribution characteristic of the audio information after wavelet transformation.
When the number of the gravel transporting in the rivei is small or the water flow velocity is slow, the strain sensor receives little pressure from the gravels so there are little deformations of the upper baffle and the lower baffle, and the analysis error of analyzing the gravel movement through the pressure change measured by the strain sensor is large. At this point, it is more suitable to analyze the gravel movement by using the audio information collected by the sound pickup device. When the number of the gravel transporting in the river is large or the water flow velocity is fast, there may be a lot of complicated signals that can be detected by detecting audio through the sound pickup device, and the analysis error of the gravel movement through the gravel transport audio information collected by the sound pickup device is relatively large. At this point, it is more suitable to analyze the gravel movement through the pressure change detected by the strain sensor.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the structure of a collecting apparatus for gravel transport pressure and transport audio according to the present invention.
FIG. 2 is a top view of the lower baffle and the protective cover in FIG. 1.
FIG. 3 is a system block diagram of the collecting system for gravel transport pressure and transport audio according to the present invention.
FIG. 4 is an operation flow diagram of the collecting method for gravel transport pressure and transport audio according to the present invention.
FIG. 5 is a peak frequency probability density distribution diagram of three sound signals of gravel, ship, and water according to an embodiment of the present invention.
FIG. 6 is a pitch frequency probability density distribution diagram of three sound signals of gravel, ship, and water according to an embodiment of the present invention.
FIG. 7 is an energy distribution characteristic diagram of three sound signals of gravel, ship, and water according to an embodiment of the present invention;
FIG. 8 is a time domain waveform of the synthesized sound according to an embodiment of the present invention. .
FIG. 9 is a characteristic distribution diagram of a sound segment according to an embodiment of the present invention. .
FIG. 10 is an identification result of a synthesized signal according to an embodiment of the present invention.
Description of Reference Signs 1: upper baffle;
2: lower baffle;
3: protective cover;
4: sound pickup device;
The collecting apparatus may be recycled periodically without fear of burying. The base station is provided on the river bank. One base station may supervise the collected information of a plurality of collecting apparatuses. The preprocessing of the collected information by the base station mainly refers to preprocess the sound information, including filtering and enhancement or other processing methods, and the base station transmits the preprocessed collected information to the server. The base station plays a role of transmitting and preprocessing, so that the burden of data transmission is reduced and the utilization efficiency of the collected information is improved.
By means of the server, the gravel transport condition may be monitored remotely in real time, and the spatial distribution of gravel movement may be observed.
Further and preferably, the collecting system for gravel transport pressure and transport audio is connected with the base station through a cable, and the base station and the server are connected through wireless communications.
In the collecting system for gravel transport pressure and transport audio mentioned above, the audio information and pressure information collected by the collecting apparatus are transmitted to the base station on the bank through the cable. Although the transmission method may also be wireless transmission, considering the complex underwater environment, weak wireless signal, and limited transmission distance, cable transmission is selected. With cable transmission, the information is more stable and the transmission distance is longer. After testing, the transmission distance of the cable transmission may reach 3000 meters, and the cable transmission may be usable in a wide range. One base station may manage the collecting apparatuses that are within a large range.
Further and preferably, the cables are arranged to cling to the river bed in a straight line. In daily life, there are often many ships, as well as floating debris in the river, and also many aquatic plants, as well as fish and shrimp swimming back and forth in the river. If the cables are floating on the river or in the river, the cables are easily entangled with ships, debris, or aquatic plants, which may easily cause safety accidents. Therefore, the cables are arranged to cling to the river bed so that the above situation may be avoided. In addition, the impact of the water flow at the bottom of the river is relatively small, which can protect the cable to some extent. Arranging the cables in a straight line on the river bed, it is also an objective to avoid the cables entangling with debris because of too much cables, and the cost may also be reduced.
A collecting method for gravel transport pressure and transport audio includes:
a step of arranging a collecting apparatus: arranging a plurality of collecting apparatus crossly and equidistantly respectively along a length and a width direction of the river bed; fixing the collecting apparatus on a river bed through a fixing mean; and a cable between the collecting apparatus and a base station on a bank being arranged to cling to the river bed and in a straight line;
a step of collecting information: collecting the gravel transport audio information by a sound pickup device in real time; collecting pressure information of the gravels received by an upper baffle and a lower baffle by a strain sensor in real time; and transmitting the collected audio information and the pressure information to the base station through the cable;
preprocessing the collected audio information and pressure information in the base station, and transmitting the preprocessed audio information and pressure information to a server;
a step of analyzing information: preprocessing the collected audio information and pressure information in the base station, and transmitting the preprocessed audio information and pressure information to a server; analyzing and comparing the collected audio information and pressure information by the server; when a volume decibel corresponding to the audio information is smaller than a volume preset value, or a pressure value corresponding to the pressure information is smaller than a pressure preset value, determining a gravel transport movement amount and a gravel transport movement trajectory by analyzing the volume decibel corresponding to the audio information; and when the volume decibel corresponding to the audio information is greater than or equal to the volume preset value, or the pressure value corresponding to the pressure information is greater than or equal to the pressure preset value, determining the gravel transport movement amount and the gravel transport movement trajectory by analyzing the pressure value corresponding to the pressure information.
Further and preferably, the gravel transport audio information is identified from the audio information by analyzing a characteristic parameter of the audio information;
the characteristic parameters include a peak frequency of the audio information, a pitch frequency of the audio information, and an energy distribution characteristic of the audio information after wavelet transformation.
When the number of the gravel transporting in the rivei is small or the water flow velocity is slow, the strain sensor receives little pressure from the gravels so there are little deformations of the upper baffle and the lower baffle, and the analysis error of analyzing the gravel movement through the pressure change measured by the strain sensor is large. At this point, it is more suitable to analyze the gravel movement by using the audio information collected by the sound pickup device. When the number of the gravel transporting in the river is large or the water flow velocity is fast, there may be a lot of complicated signals that can be detected by detecting audio through the sound pickup device, and the analysis error of the gravel movement through the gravel transport audio information collected by the sound pickup device is relatively large. At this point, it is more suitable to analyze the gravel movement through the pressure change detected by the strain sensor.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the structure of a collecting apparatus for gravel transport pressure and transport audio according to the present invention.
FIG. 2 is a top view of the lower baffle and the protective cover in FIG. 1.
FIG. 3 is a system block diagram of the collecting system for gravel transport pressure and transport audio according to the present invention.
FIG. 4 is an operation flow diagram of the collecting method for gravel transport pressure and transport audio according to the present invention.
FIG. 5 is a peak frequency probability density distribution diagram of three sound signals of gravel, ship, and water according to an embodiment of the present invention.
FIG. 6 is a pitch frequency probability density distribution diagram of three sound signals of gravel, ship, and water according to an embodiment of the present invention.
FIG. 7 is an energy distribution characteristic diagram of three sound signals of gravel, ship, and water according to an embodiment of the present invention;
FIG. 8 is a time domain waveform of the synthesized sound according to an embodiment of the present invention. .
FIG. 9 is a characteristic distribution diagram of a sound segment according to an embodiment of the present invention. .
FIG. 10 is an identification result of a synthesized signal according to an embodiment of the present invention.
Description of Reference Signs 1: upper baffle;
2: lower baffle;
3: protective cover;
4: sound pickup device;
5: strain sensor;
52: base;
53: support rod;
52: base;
53: support rod;
6: receiving cavity;
7: fixing mean;
8: bolt.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following embodiments are merely used for more clearly explaining the technical solutions of the present invention, and therefore, they are only examples and cannot be used to limit the protection scope of the present invention.
The best embodiment:
Referring to FIGS. 1 and 2, the collecting apparatus for gravel transport pressure and transport audio includes an upper baffle 1, a lower baffle 2 and a protective cover 3 provided between two baffles for preventing the impact of gravels and the sediment water flow; the upper baffle, the lower baffle and the protective cover enclose a cavity; a sound pickup device for collecting the gravel transport audio and a plurality of strain sensors 51 for collecting the gravel pressure received by the upper baffle and the lower baffle during the transporting process are fixedly mounted inside the cavity; the sound pickup device is fixedly mounted on the upper baffle or the lower baffle, and the strain sensor is fixedly mounted between the upper baffle and the lower baffle.
In the present application, the collecting apparatus is arranged on the bottom surface of the river; the upper baffle, the lower baffle and the protective cover are all made of steel plates, and are fixedly connected to each other by means of bolts 8. The protective cover may prevent the impact of gravel and sediment water flow and protect the security of the electronic device inside the cavity; thus the impact of underwater environment is reduced and the lifetime of the electronic equipment is increased. At the same time, the subsequent maintenance of the devices may also be facilitated. The sound pickup device is provided inside the cavity for collecting the sound information generated by gravel transport above the collecting apparatus. The strain sensor is fixedly mounted between the upper baffle and the lower baffle for measuring the pressure information of the gravels acted on the upper baffle and the lower baffle during the transporting process of the gravels from above the apparatus; and the river bottom gravel transport movement amount and the gravel transport movement trajectory are determined by analyzing the collected audio information and pressure information.
In the specific implementation process, the upper baffle and the lower baffle are of the same size, using a steel plate having a length of 600 mm, a width of 600 mm and a thickness of 10 mm.
The protective cover is a three-dimensional rectangular frame of 502 mmx502 mmx75 mm (length x width x height) composed from a steel plate with a thickness of 2 mm. The bottom edge of the protective cover is provided with a flange of 20mm, and is fixedly connected to the lower baffle by means of screws. Eight holes are also provided on the corners of the lower baffle, with an aperture of 6 mm, for placing the collecting apparatus. Small holes of 6mm are reserved on each edge of the protective cover for placing the elastic element, and the elastic element is used to join the gap between the upper edge of the protective cover and the upper baffle, so as to ensure that there is no rigid connection among the strain sensor and the upper baffle and the lower baffle and maintain the sensitivity to pressure change. Further, the arrangement of the elastic element may also seal the entire cavity to prevent water entering into the cavity; and the elastic element may be selected as elastic plastic strips.
In the present embodiment, the sound pickup device 4 is fixedly mounted on the middle area of the upper baffle. Since there is a certain distance between the upper baffle and the lower baffle, and the gravels pass above the collecting apparatus, it is more advantageous to mount the sound pickup device on the middle of the upper baffle inner side than on the lower baffle, so that a louder volume of the audio may be received, and thus the reception efficiency and reception accuracy of the audio may be improved.
In the present embodiment, a waterproof sound pickup device is sealed in the cavity. The sound-sensitive element of the sound pickup device is clung to the upper baffle so that the sound pickup device may only detect the sound produced by the gravel movement above the baffle on the collecting apparatus; after experiments, it was found that even if one is speaking loudly beside the collecting apparatus, the sound pickup device would not collect any sound. The situation that the gravel movement sound is submerged due to excessive environmental noise is solved, and the difficulty of analyzing the sound information is reduced.
In the present embodiment, the upper sensing point of the strain sensor is fixedly attached to an upper baffle through an elastic element, and a support rod 53 along the vertical direction and a columnar base 52 are provided between a lower sensing point of the strain sensor and the lower baffle. A top end of the support rod is fixedly attached to the lower sensing point of the strain sensor, and a bottom end of the support rod is fixedly connected to a top of the base; an inner side of the lower baffle corresponding to a position of the base is recessed inward to provide a receiving cavity 6 for receiving the base, and a bottom of the base is protruded into the receiving cavity and is attached to the lower baffle.
In the collecting apparatus for gravel transport pressure and transport audio mentioned above, the detection principle of the strain sensor is as follows: sensing elements are fixedly provided between the upper baffle and the lower baffle, and the sensing element may be mechanically deformed along with the upper baffle or the lower baffle; the strain sheet of the
DETAILED DESCRIPTION OF THE EMBODIMENTS
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following embodiments are merely used for more clearly explaining the technical solutions of the present invention, and therefore, they are only examples and cannot be used to limit the protection scope of the present invention.
The best embodiment:
Referring to FIGS. 1 and 2, the collecting apparatus for gravel transport pressure and transport audio includes an upper baffle 1, a lower baffle 2 and a protective cover 3 provided between two baffles for preventing the impact of gravels and the sediment water flow; the upper baffle, the lower baffle and the protective cover enclose a cavity; a sound pickup device for collecting the gravel transport audio and a plurality of strain sensors 51 for collecting the gravel pressure received by the upper baffle and the lower baffle during the transporting process are fixedly mounted inside the cavity; the sound pickup device is fixedly mounted on the upper baffle or the lower baffle, and the strain sensor is fixedly mounted between the upper baffle and the lower baffle.
In the present application, the collecting apparatus is arranged on the bottom surface of the river; the upper baffle, the lower baffle and the protective cover are all made of steel plates, and are fixedly connected to each other by means of bolts 8. The protective cover may prevent the impact of gravel and sediment water flow and protect the security of the electronic device inside the cavity; thus the impact of underwater environment is reduced and the lifetime of the electronic equipment is increased. At the same time, the subsequent maintenance of the devices may also be facilitated. The sound pickup device is provided inside the cavity for collecting the sound information generated by gravel transport above the collecting apparatus. The strain sensor is fixedly mounted between the upper baffle and the lower baffle for measuring the pressure information of the gravels acted on the upper baffle and the lower baffle during the transporting process of the gravels from above the apparatus; and the river bottom gravel transport movement amount and the gravel transport movement trajectory are determined by analyzing the collected audio information and pressure information.
In the specific implementation process, the upper baffle and the lower baffle are of the same size, using a steel plate having a length of 600 mm, a width of 600 mm and a thickness of 10 mm.
The protective cover is a three-dimensional rectangular frame of 502 mmx502 mmx75 mm (length x width x height) composed from a steel plate with a thickness of 2 mm. The bottom edge of the protective cover is provided with a flange of 20mm, and is fixedly connected to the lower baffle by means of screws. Eight holes are also provided on the corners of the lower baffle, with an aperture of 6 mm, for placing the collecting apparatus. Small holes of 6mm are reserved on each edge of the protective cover for placing the elastic element, and the elastic element is used to join the gap between the upper edge of the protective cover and the upper baffle, so as to ensure that there is no rigid connection among the strain sensor and the upper baffle and the lower baffle and maintain the sensitivity to pressure change. Further, the arrangement of the elastic element may also seal the entire cavity to prevent water entering into the cavity; and the elastic element may be selected as elastic plastic strips.
In the present embodiment, the sound pickup device 4 is fixedly mounted on the middle area of the upper baffle. Since there is a certain distance between the upper baffle and the lower baffle, and the gravels pass above the collecting apparatus, it is more advantageous to mount the sound pickup device on the middle of the upper baffle inner side than on the lower baffle, so that a louder volume of the audio may be received, and thus the reception efficiency and reception accuracy of the audio may be improved.
In the present embodiment, a waterproof sound pickup device is sealed in the cavity. The sound-sensitive element of the sound pickup device is clung to the upper baffle so that the sound pickup device may only detect the sound produced by the gravel movement above the baffle on the collecting apparatus; after experiments, it was found that even if one is speaking loudly beside the collecting apparatus, the sound pickup device would not collect any sound. The situation that the gravel movement sound is submerged due to excessive environmental noise is solved, and the difficulty of analyzing the sound information is reduced.
In the present embodiment, the upper sensing point of the strain sensor is fixedly attached to an upper baffle through an elastic element, and a support rod 53 along the vertical direction and a columnar base 52 are provided between a lower sensing point of the strain sensor and the lower baffle. A top end of the support rod is fixedly attached to the lower sensing point of the strain sensor, and a bottom end of the support rod is fixedly connected to a top of the base; an inner side of the lower baffle corresponding to a position of the base is recessed inward to provide a receiving cavity 6 for receiving the base, and a bottom of the base is protruded into the receiving cavity and is attached to the lower baffle.
In the collecting apparatus for gravel transport pressure and transport audio mentioned above, the detection principle of the strain sensor is as follows: sensing elements are fixedly provided between the upper baffle and the lower baffle, and the sensing element may be mechanically deformed along with the upper baffle or the lower baffle; the strain sheet of the
9 strain sensor is pasted on the sensing element and the strain sheet may be mechanically deformed along with the sensing piece; the strain sheet is made of metal, and the resistance of the metal changes with the degree of deformation; as the resistance changes, the corresponding detected voltage also changes, and the change of the corresponding received pressure may be determined through the detected voltage. The elastic element is provided between the upper sensing point of the strain sensor and the upper baffle, so that the rigid connection between the upper sensor point of strain sensor and upper baffle may be avoided, and the sensitivity of the strain sensor to pressure change may be ensured at the same time. The inner side of the lower baffle corresponding to the position of the base is recessed inward to provide a receiving cavity for receiving the base, and the bottom of the base is protruded into the receiving cavity and is attached to the lower baffle. The above configuration facilitates the installation and removal of the entire component, while preventing the base from being unstable and easily slipping. The strain sensor is in a cantilever structure. To protect the sensitivity of strain sheet, flexible waterproof treatment is required; the base is placed in the receiving cavity reserved from the lower baffle; The upper sensing point of the strain sensor and the upper baffle are fixed by screws, and the overall structure also plays a role of supporting.
In the present embodiment, the protective cover is provided with a round hole for placing a cable. The cable includes data lines and power lines. A waterproof ring may be provided at the round hole, and the protective cover and the waterproof ring are used in combination to prevent the river water from entering into the cavity. The round hole is provided on the middle area of the lower edge of the protective cover, with an aperture of 25mm. The data lines and the power lines of the device inside the cavity are assembled into a cable and then passed out through the round hole.
In the present embodiment, the collecting apparatus further includes a fixing mean 7 for fixing the collecting apparatus on a river bed, and the fixing mean is fixedly mounted at the bottom of the lower baffle.
By fixing the collecting apparatus of the present application to the bottom of the river, the gravel transport movement amount and the gravel transport movement trajectory at or near the site can be collected at a fixed point. In practical use, a plurality of collecting apparatus may be arranged equidistantly at the bottom of the river. Fixing the collecting apparatus is also beneficial to improve the accuracy of gravel transport analysis.
In the present invention, the principle of the strain sensor to detect the pressure of the gravel acted on the collecting apparatus is as follows: after putting the collecting apparatus into the water, the water pressure received by the upper baffle detected by the strain sensor is P, , and the to water pressure received by the lower baffle is /32, and the total water pressure received by the collecting apparatus is:
P = P,- P2 = pgAh wherein Ah refers to the thickness of the strain sensor, and the thickness may almost be negligible, i.e. Ah 0, comparing to the water depth when the river is deep.
Since the water pressure received by the upper baffle and the lower baffle reaches a balance, the problem that whether pressure change is caused by gravel ballast or water level fluctuations, which is resulted from the increase or decrease of the water level during field observations, can be solved.
Referring to FIG. 3, the collecting system for gravel transport pressure and transport audio includes a plurality of collecting apparatus arranged on the riµ -r bed, a base station provided on a bank for preprocessing the collected information, and a server communicatively connected with the base station; the collecting apparatus is the collecting apparatus for gravel transport pressure and transport audio according to any one of claims 1 to 6; and the collecting apparatus is communicatively connected with the base station; the collecting system for gravel transport pressure and transport audio is connected with the base station through a cable, and the base station and the server are connected through wireless communications; the cable is arranged to cling to the river bed and in a straight line.
In the collecting system for gravel transport pressure and transport audio mentioned above, a plurality of collecting apparatuses are distributed uniformly at the bottom of the river and are used to detect the gravel transport condition at or around the arranged point.
The collecting apparatus may be recycled periodically without fear of burying. The base station is provided on the river bank. One base station may supervise the collected information of a plurality of collecting apparatuses. The preprocessing of the collected information by the base station mainly refers to preprocess the sound information, including filtering and enhancement or other processing methods, and the base station transmits the preprocessed collected information to the server. The base station plays a role of transmitting and preprocessing, so that the burden of data transmission is reduced and the utilization efficiency of the collected information is improved.
By means of the server, the gravel transport condition may be monitored remotely in real time, and the spatial distribution of gravel movement may be observed.
In the collecting system for gravel transport pressure and transport audio mentioned above, the audio information and pressure information collected by the collecting apparatus are transmitted to the base station on the bank through the cable. Although the transmission method may also be wireless transmission, considering the complex underwater environment, weak wireless signal, and limited transmission distance, cable transmission is selected. With cable transmission, the information is more stable and the transmission distance is longer. After testing, the transmission distance of the cable transmission may reach 3000 meters, and the cable transmission may be usable in a wide range. One base station may manage the collecting apparatuses that are within a large range.
In daily life, there are often many ships, as well as floating debris in the river, and also many aquatic plants, as well as fish and shrimp swimming back and forth in the river. If the cables are floating on the river or in the river, the cables are easily entangled with ships, debris, or aquatic plants, which may easily cause safety accidents. Therefore, the cables are arranged to cling to the river bed so that the above situation may be avoided. In addition, the impact of the water flow at the bottom of the river is relatively small, which can protect the cable to some extent. Arranging the cables in a straight line on the river bed, it is also an objective to avoid the cables entangling with debris and reduce the cost.
Referring to FIG. 4, the collecting method for gravel transport pressure and transport audio includes:
a step of arranging a collecting apparatus: arranging a plurality of collecting apparatus crossly and equidistantly respectively along a length and a width direction of the river bed; fixing the collecting apparatus on a river bed through a fixing mean; and arranging a cable between the collecting apparatus and a base station on a bank to keep the cable being arranged to cling to the river bank and in a straight line; before observing in the field, the collecting apparatus may be assembled in advance indoors. Pass the wire rope through the screw hole of the housing of the collecting apparatus and fix it on the anchor chain of the ship, and fix the collecting apparatus every 500 meters. The data lines and the power supply lines of the collecting apparatus are all wrapped in a protective hose, and then the hose is wound along the anchor chain. The anchor chain mainly plays the role of fixing the device and the transmission line.
The cables of all observation points are extended along the anchor chain and along the bottom of the river to the bank and are connected to the base station.
a step of collecting information: collecting the gravel transport audio information by a sound pickup device in real time,; collecting pressure information of the gravels received by an upper baffle and a lower baffle by a strain sensor in real time; and transmitting the collected audio information and the pressure information to the base station through the cable;
preprocessing the collected audio information and pressure information in the base station, and transmitting the preprocessed audio information and pressure information to a server.
a step of analyzing information: preprocessing the collected audio information and pressure information in the base station, and transmitting the preprocessed audio information and pressure information to a server; analyzing and comparing the collected audio information and pressure information by the server; when a volume decibel corresponding to the audio information is smaller than a volume preset value, or a pressure value corresponding to the pressure information is smaller than a pressure preset value, determining a gravel transport movement amount and a gravel transport movement trajectory by analyzing the volume decibel corresponding to the audio information; and when the volume decibel corresponding to the audio information is greater than or equal to the volume preset value, or the pressure value corresponding to the pressure information is greater than or equal to the pressure preset value, determining the gravel transport movement amount and the gravel transport movement trajectory by analyzing the pressure value corresponding to the pressure information. Through the preprocessing of the information collected by the collecting apparatus in the base station, the burden of data transmission is reduced.
When the number of the gravel transporting in the river is small or the water flow velocity is slow, the strain sensor receives little pressure from the gravels so there are little deformations of the upper baffle and the lower baffle, and the analysis error of analyzing the gravel movement through the pressure change measured by the strain sensor is large. At this point, it is more suitable to analyze the gravel movement by using the audio information collected by the sound pickup device; When the number of the gravel transporting in the river is large or the water flow velocity is fast, there may be a lot of complicated signals that can be detected by detecting audio through the sound pickup device, and the analysis error of the gravel movement through the gravel transport audio information collected by the sound pickup device is large. At this point, it is more suitable to analyze the gravel movement through the pressure change detected by the strain sensor.
Referring to FIGS. 5-7, the gravel transport audio information is identified from the audio information by analyzing a characteristic parameter of the audio information;
the characteristic parameters include a peak frequency of the audio information, a pitch frequency of the audio information, and an energy distribution characteristic of the audio information after wavelet transformation. It is assumed that the audio information includes three kinds of sound signals:
gravel, ship and water. The specific analysis is as follows:
(1) the gravel transport audio information is identified from the audio information by analyzing the peak frequency of the audio information. According to the spectrum analysis of the three types of signals, the peak frequency of the three kinds of sounds of gravel, ship and water correspond to different ranges. The peak frequency of gravel is at about 3200 Hz, the peak frequency of ship is at about 100 Hz, and the peak frequency of water is at about 25 Hz. After analyzing the peak frequency of the three kinds of sounds of gravel, ship and water, with the sample size of 300, 100, 200 respectively, the peak frequency probability density distribution curve is obtained, and the figure is shown in FIG. 5.
As can be seen from FIG. 5, the peak frequency distributions of gravels, ships and water are obviously different. The peak frequency of gravels is in the range of 1400 to 4000 Hz and is affected by the particle size and material; the peak frequency of ships is mainly between 25Hz and 500 Hz, and is affected by the ship type; and the peak frequency of water is between 20Hz and 25Hz. There is a clear distinction among them, so that the gravel transport audio information may be identified from the mixed audio information.
(2) the gravel transport audio information is identified from the audio information by analyzing the pitch frequency of the audio information. After analyzing the pitch frequency of the three kinds of sounds of gravel, ship and water, the probability density distribution curve is obtained, and the figure is shown in FIG. 6. The pitch frequency of gravels is between 2000Hz and 3800Hz; the pitch frequency of the ship is affected by the ship type and is between 500 and 1500 Hz; the pitch frequency of water is around 25-40Hz, which is very close to its dominant frequency. It can be seen that the pitch frequency characteristic of gravels is obviously different from those of the other two kinds of sounds. By using the difference of the pitch frequencies of the three, the gravel transport audio information may be identified from the mixed audio information.
(3) the gravel transport audio information is identified from the audio information by analyzing the energy distribution characteristic of the audio information after wavelet transformation. To acquire the energy characteristic vector of the three signals of gravel, ship and water respectively, and in order to make the resulting characteristics to be representative, the sample size of the gravel sample is 300, the sample size of th- ship is 100, and the sample size of water is 200. Finally the average characteristic vector of all samples of each signal is obtained.
As shown in FIG. 7, Eaj represents the low-frequency coefficients of the audio information after wavelet transformation, and Edi¨Ed6 represent the 1-6th order high-frequency coefficients of the audio information after wavelet transformation respectively in FIG. 7. It can be seen that the difference in the energy distribution of the three signals is as follows:
a: the sound energy of gravels is mainly concentrated on the 1st to 3rd order high frequency coefficients, which exceeds 80% of the total energy, and the energy on the low frequency coefficients is less than 10%;
b: the sound energy of the ship sound is mainly concentrated on the low frequency coefficients and the 4th to 6th order high frequency coefficients;
c: over 90% of the sound energy of water is concentrated on low frequency coefficients.
Thus, the gravel transport audio information is identified from the mixed audio information.
From the above analysis, by comparing the difference between the sound signal of gravels and the sound signal of the other two kinds, the distribution range of characteristic parameters describing the gravel movement sound can be obtained. A confidence interval with a confidence level of 0.8 is selected, and a peak frequency range of 1400 to 4000 Hz and a pitch frequency range of 2000 to 3800 Hz of gravels are obtained. The wavelet-transformed energy distribution characteristics of gravels may be expressed by the total energ3, on the high frequency coefficients of the 1st to the 3rd order, and be denoted as T, and the range of T is 0.8-1.
In the specific operation, before performing the characteristic analysis for the collected audio information, the audio information needs to be preprocessed. The spectral subtraction is used to denoise the audio information. The inventor has tried other noise reduction methods during the design process, for example Fast Fourier Transform (FFT), but the effect is unobvious.
Referring to FIGS. 8-10, whether the above three characteristic parameters can describe the gravel movement sound is verified, and the identification effect analysis is performed by using the synthesized complex audio signal. Specific analysis is as follows: a series of complex sound signals, such as water sound, ship navigation sound, gravel movement sound, thunder sound, rain sound and bird sound, are included in the synthesized signal, and the time domain waveform of the synthesized signal is shown in Figure 8. The target signal is detected and extracted from the signal, and a total of 677 sound segments are obtained. The peak frequency, the pitch frequency of each segment, and the energy distribution T after wavelet transformation are calculated. Each segment is represented by a vector (fl, f2, T), and the characteristic distribution of the 677 fragments that are obtained is shown in FIG. 9. The cuboid in the figure is the characteristic distribution area of the gravel movement sound, and a total of 11 segments out of 677 segments fall into this area. It is shown in FIG. 9 that there are 11 times of gravel collision sounds in the synthetic signal, while the identification result of the human's ear is 12 times, and the difference is only one time. FIG. 10 is the identification result corresponding to the time domain waveform.
Finally, it should be noted that the embodiments described herein are only for the purpose of illustrating the technical solution of the present invention, and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the embodiments, it would be understood by a person skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present disclosure, and such changes and modifications are contemplated by the present invention.
In the present embodiment, the protective cover is provided with a round hole for placing a cable. The cable includes data lines and power lines. A waterproof ring may be provided at the round hole, and the protective cover and the waterproof ring are used in combination to prevent the river water from entering into the cavity. The round hole is provided on the middle area of the lower edge of the protective cover, with an aperture of 25mm. The data lines and the power lines of the device inside the cavity are assembled into a cable and then passed out through the round hole.
In the present embodiment, the collecting apparatus further includes a fixing mean 7 for fixing the collecting apparatus on a river bed, and the fixing mean is fixedly mounted at the bottom of the lower baffle.
By fixing the collecting apparatus of the present application to the bottom of the river, the gravel transport movement amount and the gravel transport movement trajectory at or near the site can be collected at a fixed point. In practical use, a plurality of collecting apparatus may be arranged equidistantly at the bottom of the river. Fixing the collecting apparatus is also beneficial to improve the accuracy of gravel transport analysis.
In the present invention, the principle of the strain sensor to detect the pressure of the gravel acted on the collecting apparatus is as follows: after putting the collecting apparatus into the water, the water pressure received by the upper baffle detected by the strain sensor is P, , and the to water pressure received by the lower baffle is /32, and the total water pressure received by the collecting apparatus is:
P = P,- P2 = pgAh wherein Ah refers to the thickness of the strain sensor, and the thickness may almost be negligible, i.e. Ah 0, comparing to the water depth when the river is deep.
Since the water pressure received by the upper baffle and the lower baffle reaches a balance, the problem that whether pressure change is caused by gravel ballast or water level fluctuations, which is resulted from the increase or decrease of the water level during field observations, can be solved.
Referring to FIG. 3, the collecting system for gravel transport pressure and transport audio includes a plurality of collecting apparatus arranged on the riµ -r bed, a base station provided on a bank for preprocessing the collected information, and a server communicatively connected with the base station; the collecting apparatus is the collecting apparatus for gravel transport pressure and transport audio according to any one of claims 1 to 6; and the collecting apparatus is communicatively connected with the base station; the collecting system for gravel transport pressure and transport audio is connected with the base station through a cable, and the base station and the server are connected through wireless communications; the cable is arranged to cling to the river bed and in a straight line.
In the collecting system for gravel transport pressure and transport audio mentioned above, a plurality of collecting apparatuses are distributed uniformly at the bottom of the river and are used to detect the gravel transport condition at or around the arranged point.
The collecting apparatus may be recycled periodically without fear of burying. The base station is provided on the river bank. One base station may supervise the collected information of a plurality of collecting apparatuses. The preprocessing of the collected information by the base station mainly refers to preprocess the sound information, including filtering and enhancement or other processing methods, and the base station transmits the preprocessed collected information to the server. The base station plays a role of transmitting and preprocessing, so that the burden of data transmission is reduced and the utilization efficiency of the collected information is improved.
By means of the server, the gravel transport condition may be monitored remotely in real time, and the spatial distribution of gravel movement may be observed.
In the collecting system for gravel transport pressure and transport audio mentioned above, the audio information and pressure information collected by the collecting apparatus are transmitted to the base station on the bank through the cable. Although the transmission method may also be wireless transmission, considering the complex underwater environment, weak wireless signal, and limited transmission distance, cable transmission is selected. With cable transmission, the information is more stable and the transmission distance is longer. After testing, the transmission distance of the cable transmission may reach 3000 meters, and the cable transmission may be usable in a wide range. One base station may manage the collecting apparatuses that are within a large range.
In daily life, there are often many ships, as well as floating debris in the river, and also many aquatic plants, as well as fish and shrimp swimming back and forth in the river. If the cables are floating on the river or in the river, the cables are easily entangled with ships, debris, or aquatic plants, which may easily cause safety accidents. Therefore, the cables are arranged to cling to the river bed so that the above situation may be avoided. In addition, the impact of the water flow at the bottom of the river is relatively small, which can protect the cable to some extent. Arranging the cables in a straight line on the river bed, it is also an objective to avoid the cables entangling with debris and reduce the cost.
Referring to FIG. 4, the collecting method for gravel transport pressure and transport audio includes:
a step of arranging a collecting apparatus: arranging a plurality of collecting apparatus crossly and equidistantly respectively along a length and a width direction of the river bed; fixing the collecting apparatus on a river bed through a fixing mean; and arranging a cable between the collecting apparatus and a base station on a bank to keep the cable being arranged to cling to the river bank and in a straight line; before observing in the field, the collecting apparatus may be assembled in advance indoors. Pass the wire rope through the screw hole of the housing of the collecting apparatus and fix it on the anchor chain of the ship, and fix the collecting apparatus every 500 meters. The data lines and the power supply lines of the collecting apparatus are all wrapped in a protective hose, and then the hose is wound along the anchor chain. The anchor chain mainly plays the role of fixing the device and the transmission line.
The cables of all observation points are extended along the anchor chain and along the bottom of the river to the bank and are connected to the base station.
a step of collecting information: collecting the gravel transport audio information by a sound pickup device in real time,; collecting pressure information of the gravels received by an upper baffle and a lower baffle by a strain sensor in real time; and transmitting the collected audio information and the pressure information to the base station through the cable;
preprocessing the collected audio information and pressure information in the base station, and transmitting the preprocessed audio information and pressure information to a server.
a step of analyzing information: preprocessing the collected audio information and pressure information in the base station, and transmitting the preprocessed audio information and pressure information to a server; analyzing and comparing the collected audio information and pressure information by the server; when a volume decibel corresponding to the audio information is smaller than a volume preset value, or a pressure value corresponding to the pressure information is smaller than a pressure preset value, determining a gravel transport movement amount and a gravel transport movement trajectory by analyzing the volume decibel corresponding to the audio information; and when the volume decibel corresponding to the audio information is greater than or equal to the volume preset value, or the pressure value corresponding to the pressure information is greater than or equal to the pressure preset value, determining the gravel transport movement amount and the gravel transport movement trajectory by analyzing the pressure value corresponding to the pressure information. Through the preprocessing of the information collected by the collecting apparatus in the base station, the burden of data transmission is reduced.
When the number of the gravel transporting in the river is small or the water flow velocity is slow, the strain sensor receives little pressure from the gravels so there are little deformations of the upper baffle and the lower baffle, and the analysis error of analyzing the gravel movement through the pressure change measured by the strain sensor is large. At this point, it is more suitable to analyze the gravel movement by using the audio information collected by the sound pickup device; When the number of the gravel transporting in the river is large or the water flow velocity is fast, there may be a lot of complicated signals that can be detected by detecting audio through the sound pickup device, and the analysis error of the gravel movement through the gravel transport audio information collected by the sound pickup device is large. At this point, it is more suitable to analyze the gravel movement through the pressure change detected by the strain sensor.
Referring to FIGS. 5-7, the gravel transport audio information is identified from the audio information by analyzing a characteristic parameter of the audio information;
the characteristic parameters include a peak frequency of the audio information, a pitch frequency of the audio information, and an energy distribution characteristic of the audio information after wavelet transformation. It is assumed that the audio information includes three kinds of sound signals:
gravel, ship and water. The specific analysis is as follows:
(1) the gravel transport audio information is identified from the audio information by analyzing the peak frequency of the audio information. According to the spectrum analysis of the three types of signals, the peak frequency of the three kinds of sounds of gravel, ship and water correspond to different ranges. The peak frequency of gravel is at about 3200 Hz, the peak frequency of ship is at about 100 Hz, and the peak frequency of water is at about 25 Hz. After analyzing the peak frequency of the three kinds of sounds of gravel, ship and water, with the sample size of 300, 100, 200 respectively, the peak frequency probability density distribution curve is obtained, and the figure is shown in FIG. 5.
As can be seen from FIG. 5, the peak frequency distributions of gravels, ships and water are obviously different. The peak frequency of gravels is in the range of 1400 to 4000 Hz and is affected by the particle size and material; the peak frequency of ships is mainly between 25Hz and 500 Hz, and is affected by the ship type; and the peak frequency of water is between 20Hz and 25Hz. There is a clear distinction among them, so that the gravel transport audio information may be identified from the mixed audio information.
(2) the gravel transport audio information is identified from the audio information by analyzing the pitch frequency of the audio information. After analyzing the pitch frequency of the three kinds of sounds of gravel, ship and water, the probability density distribution curve is obtained, and the figure is shown in FIG. 6. The pitch frequency of gravels is between 2000Hz and 3800Hz; the pitch frequency of the ship is affected by the ship type and is between 500 and 1500 Hz; the pitch frequency of water is around 25-40Hz, which is very close to its dominant frequency. It can be seen that the pitch frequency characteristic of gravels is obviously different from those of the other two kinds of sounds. By using the difference of the pitch frequencies of the three, the gravel transport audio information may be identified from the mixed audio information.
(3) the gravel transport audio information is identified from the audio information by analyzing the energy distribution characteristic of the audio information after wavelet transformation. To acquire the energy characteristic vector of the three signals of gravel, ship and water respectively, and in order to make the resulting characteristics to be representative, the sample size of the gravel sample is 300, the sample size of th- ship is 100, and the sample size of water is 200. Finally the average characteristic vector of all samples of each signal is obtained.
As shown in FIG. 7, Eaj represents the low-frequency coefficients of the audio information after wavelet transformation, and Edi¨Ed6 represent the 1-6th order high-frequency coefficients of the audio information after wavelet transformation respectively in FIG. 7. It can be seen that the difference in the energy distribution of the three signals is as follows:
a: the sound energy of gravels is mainly concentrated on the 1st to 3rd order high frequency coefficients, which exceeds 80% of the total energy, and the energy on the low frequency coefficients is less than 10%;
b: the sound energy of the ship sound is mainly concentrated on the low frequency coefficients and the 4th to 6th order high frequency coefficients;
c: over 90% of the sound energy of water is concentrated on low frequency coefficients.
Thus, the gravel transport audio information is identified from the mixed audio information.
From the above analysis, by comparing the difference between the sound signal of gravels and the sound signal of the other two kinds, the distribution range of characteristic parameters describing the gravel movement sound can be obtained. A confidence interval with a confidence level of 0.8 is selected, and a peak frequency range of 1400 to 4000 Hz and a pitch frequency range of 2000 to 3800 Hz of gravels are obtained. The wavelet-transformed energy distribution characteristics of gravels may be expressed by the total energ3, on the high frequency coefficients of the 1st to the 3rd order, and be denoted as T, and the range of T is 0.8-1.
In the specific operation, before performing the characteristic analysis for the collected audio information, the audio information needs to be preprocessed. The spectral subtraction is used to denoise the audio information. The inventor has tried other noise reduction methods during the design process, for example Fast Fourier Transform (FFT), but the effect is unobvious.
Referring to FIGS. 8-10, whether the above three characteristic parameters can describe the gravel movement sound is verified, and the identification effect analysis is performed by using the synthesized complex audio signal. Specific analysis is as follows: a series of complex sound signals, such as water sound, ship navigation sound, gravel movement sound, thunder sound, rain sound and bird sound, are included in the synthesized signal, and the time domain waveform of the synthesized signal is shown in Figure 8. The target signal is detected and extracted from the signal, and a total of 677 sound segments are obtained. The peak frequency, the pitch frequency of each segment, and the energy distribution T after wavelet transformation are calculated. Each segment is represented by a vector (fl, f2, T), and the characteristic distribution of the 677 fragments that are obtained is shown in FIG. 9. The cuboid in the figure is the characteristic distribution area of the gravel movement sound, and a total of 11 segments out of 677 segments fall into this area. It is shown in FIG. 9 that there are 11 times of gravel collision sounds in the synthetic signal, while the identification result of the human's ear is 12 times, and the difference is only one time. FIG. 10 is the identification result corresponding to the time domain waveform.
Finally, it should be noted that the embodiments described herein are only for the purpose of illustrating the technical solution of the present invention, and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the embodiments, it would be understood by a person skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present disclosure, and such changes and modifications are contemplated by the present invention.
Claims (10)
1. A collecting apparatus for gravel transport pressure and transport audio, comprising: an upper baffle, a lower baffle and a protective cover provided between two baffles for preventing the impact of gravels and the sediment water flow; the upper baffle, the lower baffle and the protective cover enclose a cavity; a sound pickup device for collecting the gravel transport audio and a plurality of strain sensors for collecting the gravel pressure received by the upper baffle and the lower baffle during the transporting process are fixedly mounted inside the cavity; the sound pickup device is fixedly mounted on the upper baffle or the lower baffle, and the plurality of strain sensors are fixedly mounted between the upper baffle and the lower baffle.
2. The collecting apparatus for gravel transport pressure and transport audio of claim 1, wherein the sound pickup device is fixedly mounted in the middle area of the upper baffle.
3. The collecting apparatus for gravel transport pressure and transport audio of claim 1, wherein an upper sensing point of the strain sensor is fixedly attached to the upper baffle through an elastic element, and a support rod along a vertical direction and a columnar base are provided between a lower sensing point of the strain sensor and the lower baffle; a top end of the support rod is fixedly attached to the lower sensing point of the strain sensor, and a bottom end of the support rod is fixedly connected to a top of the base; an inner side of the lower baffle corresponding to a position of the base is recessed inward to provide a receiving cavity for receiving the base, and a bottom of the base is protruded into the receiving cavity and is attached to the lower baffle.
4. The collecting apparatus for gravel transport pressure and transport audio of claim 1, wherein the protective cover is provided with a round hole for placing a cable.
5. The collecting apparatus for gravel transport pressure and transport audio of claim 1, wherein the collecting apparatus further includes a fixing mean for fixing the collecting apparatus on a river bed, and the fixing mean is fixedly mounted at a bottom of the lower baffle.
6. A collecting system for gravel transport pressure and transport audio, comprising a plurality of collecting apparatus arranged on the river bed, a base station provided on a bank for preprocessing the collected information, and a server communicatively connected with the base station; the collecting apparatus is the collecting apparatus for gravel transport pressure and transport audio according to any one of claims 1 to 5; and the collecting apparatus is communicatively connected with the base station.
7. The collecting system for gravel transport pressure and transport audio of claim 6, wherein the collecting system for gravel transport pressure and transport audio is connected with the base station through a cable, and the base station and the server are connected through wireless communications.
8. The collecting system for gravel transport pressure and transport audio of claim 7, wherein the cable is arranged to cling to a river bed and in a straight line.
9. A collecting method for gravel transport pressure and transport audio, comprising:
a step of arranging a collecting apparatus: arranging a plurality of collecting apparatus crossly and equidistantly respectively along a length and a width direction of a river bed; fixing the collecting apparatus on the river bed through a fixing mean; and a cable between the collecting apparatus and a base station on a bank being arranged to cling to the river bed and in a straight line;
a step of collecting information: collecting the gravel transport audio information by a sound pickup device in real time; collecting pressure inforrnation of the gravels received by an upper baffle and a lower baffle by a strain sensor in real time; and transmitting the collected audio information and the pressure information to the base station through the cable;
a step of analyzing information: preprocessing the collected audio information and pressure information in the base station, and transmitting the preprocessed audio information and pressure information to a server; analyzing and comparing the collected audio information and pressure information by the server; when a volume decibel corresponding to the audio information is smaller than a volume preset value, or a pressure value corresponding to the pressure information is smaller than a pressure preset value, determining a gravel transport movement amount and a gravel transport movement trajectory by analyzing the volume decibel corresponding to the audio information; and when the volume decibel corresponding to the audio information is greater than or equal to the volume preset value, or the pressure value corresponding to the pressure information is greater than or equal to the pressure preset value, determining the gravel transport movement amount and the gravel transport movement trajectory by analyzing the pressure value corresponding to the pressure inforniation.
a step of arranging a collecting apparatus: arranging a plurality of collecting apparatus crossly and equidistantly respectively along a length and a width direction of a river bed; fixing the collecting apparatus on the river bed through a fixing mean; and a cable between the collecting apparatus and a base station on a bank being arranged to cling to the river bed and in a straight line;
a step of collecting information: collecting the gravel transport audio information by a sound pickup device in real time; collecting pressure inforrnation of the gravels received by an upper baffle and a lower baffle by a strain sensor in real time; and transmitting the collected audio information and the pressure information to the base station through the cable;
a step of analyzing information: preprocessing the collected audio information and pressure information in the base station, and transmitting the preprocessed audio information and pressure information to a server; analyzing and comparing the collected audio information and pressure information by the server; when a volume decibel corresponding to the audio information is smaller than a volume preset value, or a pressure value corresponding to the pressure information is smaller than a pressure preset value, determining a gravel transport movement amount and a gravel transport movement trajectory by analyzing the volume decibel corresponding to the audio information; and when the volume decibel corresponding to the audio information is greater than or equal to the volume preset value, or the pressure value corresponding to the pressure information is greater than or equal to the pressure preset value, determining the gravel transport movement amount and the gravel transport movement trajectory by analyzing the pressure value corresponding to the pressure inforniation.
10. The collecting method for gravel transport pressure and transport audio of claim 9, wherein gravel transport audio information is identified from the audio information by analyzing a characteristic parameter of the audio information; the characteristic parameters include a peak frequency of the audio inforrnation, a pitch frequency of the audio information, and an energy distribution characteristic of the audio information after wavelet transformation.
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| CN201710676847.5 | 2017-08-09 | ||
| CN201710676847.5A CN107238483B (en) | 2017-08-09 | 2017-08-09 | For defeated acquisition device, the system and method for moving pressure and defeated shifting audio of boulder and cobble |
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| CN114061902A (en) * | 2021-11-29 | 2022-02-18 | 重庆交通大学 | Real-time monitoring device, method and system for egg and gravel transportation based on image method |
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| JPH11304550A (en) * | 1998-04-27 | 1999-11-05 | Mitsubishi Heavy Ind Ltd | System for detecting avalanche of sand and stone |
| CN202502109U (en) * | 2012-03-10 | 2012-10-24 | 中国科学院水利部成都山地灾害与环境研究所 | Device and system for measuring flow velocity of debris flow movement and measuring test system |
| CN103700222B (en) * | 2012-09-28 | 2016-03-09 | 中国石油天然气股份有限公司 | A kind of construction method of oil and gas pipes mountain flood monitoring system |
| CN103437319A (en) * | 2013-05-24 | 2013-12-11 | 重庆交通大学 | Method for renovating movable-bed physical model design in upper Yangtze River pebble beach dangerous sea channel |
| CN203494155U (en) * | 2013-06-18 | 2014-03-26 | 温州大学瓯江学院 | Rainbow building-block river stone |
| CN104568376B (en) * | 2014-11-28 | 2017-03-29 | 重庆交通大学 | By the method and system of the instantaneous sediment discharge intensity of graphical analysis boulder and cobble |
| CN104698438B (en) * | 2015-03-10 | 2017-04-26 | 重庆交通大学 | Detection device and method of moving pebble in river |
| CN105279903B (en) * | 2015-10-27 | 2017-09-15 | 西南民族大学 | A kind of mountain torrents debris flow early-warning method based on monitoring pore water pressure |
| CN105571819B (en) * | 2015-12-11 | 2018-06-08 | 重庆交通大学 | For defeated voice acquisition system, harvester and its method for arranging for moving observation of boulder and cobble |
| CN106053012A (en) * | 2016-05-11 | 2016-10-26 | 兰州大学 | Impact force simulation device and experiment method during debris flow movement erosion-deposition process |
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