An automatic measuring mechanism and method for underwater plant density

Abstract

The application discloses an underwater plant density automatic measuring mechanism and method, and belongs to the field of plant density measurement. The measuring mechanism comprises a depth finder, a depth adjusting rod, a scanning device, a measuring ship and a central processing unit. The depth finder is installed on the measuring ship and is used for measuring the water depth of plants in real time. The depth adjusting rod is used for automatically adjusting the length according to the measured water depth, so as to ensure the best measuring position. The scanning device is located at the end of the depth adjusting rod and comprises multiple measuring groups. Each measuring group comprises a transmitting module and a receiving module. The transmitting module is used for transmitting red light, and the receiving module is used for receiving the red light by a CCD device. The central processing unit is used for judging whether the light intensity attenuation time is caused by plants, impurities in water or branches of plants. The number of underwater plants is counted by moving the measuring ship along the cross section of a river. The application has the advantages of high automation degree, small error, multiple applicable objects and the like, and truly realizes large-range and high-precision underwater plant density measurement.

Description

Technical Field

[0001] This invention belongs to the field of water environment management and relates to underwater plant density measurement technology, specifically to an automatic underwater plant density measurement mechanism and method. Background Technology

[0002] Underwater plants have been widely used in water environment management, constructing aquatic ecosystems and improving ecological governance. However, the growth of underwater plants increases river resistance and affects flood control. To accurately simulate the impact of underwater plants on river flood control, hydrodynamics, and the aquatic environment, it is necessary to accurately obtain river resistance, among which plant density is a key parameter for calculating river resistance. Current methods for measuring underwater plant density mainly rely on manual sampling and visual observation, which are time-consuming, labor-intensive, and inefficient, failing to meet the needs of large-scale measurements. Summary of the Invention

[0003] Purpose of the invention: To overcome the shortcomings of existing technologies, this invention provides an automatic underwater plant density measurement mechanism and method. An optical system is constructed based on optical methods. By recording the degree and time of the plant's influence on light intensity, it automatically determines whether a plant is a plant. This provides a novel method for plant quantity statistics. This method has significant advantages such as high automation, small error, and wide applicability, and truly realizes large-scale, high-precision underwater plant density measurement.

[0004] Technical solution: To achieve the above objectives, the present invention provides an automatic underwater plant density measuring mechanism, including a depth sounder, a depth adjustment rod, a scanning device, a measuring vessel, and a central processing unit;

[0005] The depth sounder is installed on the survey vessel and is used to measure the water depth at the vegetation location in real time.

[0006] The depth adjustment rod is used to automatically adjust its length according to the water depth being measured to ensure the optimal measurement position;

[0007] The scanning device is located at the end of the depth adjustment rod and includes multiple measurement groups. Each measurement group includes a transmitting module and a receiving module. The transmitting module is used to emit red light, and the receiving module receives the red light by a CCD device.

[0008] The central processing unit is used to determine whether the light intensity decreases or whether it is a plant, an impurity in the water, or a branch of a plant, based on the time it takes for the light intensity to decrease. By moving the measuring vessel along the cross section of the river, the number of underwater plants can be counted.

[0009] Furthermore, the emission module includes a linear LED light source and a rectangular shielding plate. The rectangular shielding plate is used to integrate the emission light source of the linear LED light source into a rectangular light field distribution with a width of B, where B is the pre-measured width of a single plant.

[0010] Furthermore, the depth adjustment rod includes a vertically extendable main rod and multiple telescopic thin rods for mounting the scanning device, with the telescopic thin rods arranged on the telescopic main rod.

[0011] Furthermore, the linear LED light source and rectangular shield of the transmitting module are set on one side of the telescopic rod, and the CCD device of the receiving module is set on the other side of the telescopic rod. The CCD device is used to receive the red light emitted from the opposite side. The transmitting module and receiving module on two adjacent telescopic rods are combined to form a measurement group.

[0012] Furthermore, the telescopic thin rods are arranged at equal intervals on the telescopic main rod.

[0013] Based on the above-mentioned automatic measuring mechanism, the present invention also provides a method for measuring underwater plant density using an automatic measuring mechanism, comprising the following steps:

[0014] S1: Obtain the distance h from the surveying vessel to the vegetation in the river using a depth sounder;

[0015] S2: Adjust the depth adjustment rod length to h;

[0016] S3: Start the survey vessel and move according to the set river cross section. The speed of the survey vessel is V0. During the movement of the survey vessel, the transmitting module of the survey group emits red light, and the receiving module receives the red light by the CCD device.

[0017] S4: Set the pre-measured width of a single plant to B, then the time of light intensity influence by passing through the plant is T = B / V0, the CCD device obtains light intensity D0, when it comes into contact with the plant during navigation, the light intensity decreases to D1, and after Δt time, it recovers to light intensity D0.

[0018] S5: Underwater plants have relatively uniform diameters. When the object obscures the plant for a period of time Δt between 0.9T and 1.1T, the central processing unit records that the measurement group passes by one plant. Otherwise, it is considered a non-plant and is not recorded.

[0019] S6: The central processing unit calculates the number of plants m based on the information from each measurement group obtained by the scanning device;

[0020] S7: Navigate sequentially to complete the count of plant counts in the cross-section, then move to the next cross-section to complete the count of plant counts in a certain area of ​​the river.

[0021] Furthermore, in step S3, the emitting module emits light through a linear LED light source, and then a rectangular shielding plate integrates the emitted light from the linear LED light source into a rectangular light field distribution with a width of B. This red light is received by the CCD device of the receiving module after passing through the plants.

[0022] Furthermore, in step S3, when encountering uneven plant distribution, the uneven plant distribution is adapted by increasing the number of measurement groups of the scanning device and dynamically adjusting the distance between the receiving end and the transmitting end by installing a rangefinder at the lower end of the light source. The dynamic adjustment of the distance between the telescopic rods specifically means that the distance between the transmitting module and the receiving module changes according to the different plant distribution in the measurement area. When the light signal of the receiving module is interrupted, the rangefinder installed at the lower end of the light source measures the distance and returns the measured distance L data to the central processing unit. The length L+B is used as the distance between the transmitting module and the receiving module to ensure that there is only one plant in each group, preventing the omission of plants in the same row. The distance between the transmitting end and the receiving end of each group is determined according to this method to ensure accurate statistics of unevenly distributed plants.

[0023] When encountering turbulent water flow, the depth sounder can quickly adapt to changes in water depth by increasing its sampling frequency and the response speed of the depth adjustment rod, thus ensuring the accuracy of the measurement.

[0024] When encountering water with many impurities, the central processing unit (CPU) distinguishes between plants and impurities by analyzing the patterns and durations of light intensity reduction. For example, light intensity reduction caused by plants usually follows a specific pattern and duration, while light intensity changes caused by impurities are more random.

[0025] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0026] 1. Improve measurement accuracy

[0027] This invention, by setting up a reasonable scanning device structure and utilizing the central processing unit's filtering function for occlusion time, effectively eliminates interference from impurities in the water and the occlusion caused by plant branches and leaves, enabling more accurate measurement of underwater plant density.

[0028] 2. Adaptable to various environments

[0029] The automatic telescopic function of the depth adjustment rod and the adjustability of the telescopic rod installation parameters enable the device to adapt to different water depths and plant distribution conditions.

[0030] 3. High measurement efficiency

[0031] The entire device is carried out on a survey vessel, making operation relatively simple. Simply start the device, set the vessel speed, and the survey vessel will automatically complete the measurement along the predetermined route, reducing manual intervention and complex operating procedures, thus significantly improving measurement efficiency. Attached Figure Description

[0032] Figure 1 This is a vertical schematic diagram of the measuring mechanism;

[0033] Figure 2This is a horizontal schematic diagram of the measuring mechanism;

[0034] Figure 3 This is a schematic diagram of the launch module.

[0035] Figure 4 This is a schematic diagram of the structural composition of the measurement group;

[0036] Figure 5 This is a flowchart of the measurement method for an automatic underwater plant density measuring mechanism. Detailed Implementation

[0037] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading this invention, any modifications of the invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.

[0038] like Figures 1-4 As shown, this invention provides an automatic underwater plant density measurement mechanism, including a depth sounder, a depth adjustment rod, a scanning device, a measuring vessel, and a central processing unit. The depth sounder is installed on the measuring vessel for real-time measurement of the water depth at the location of the plants. The depth adjustment rod is used to automatically adjust its length according to the measured water depth to ensure the optimal measurement position. The depth adjustment rod includes a vertically extendable main rod and multiple thin rods for mounting the scanning device. The scanning device is located at the end of the depth adjustment rod and includes multiple measurement groups. Each measurement group includes a transmitting module and a receiving module. The transmitting module emits red light, and the receiving module receives the red light using a CCD device. The central processing unit is used to determine whether the light intensity decreases based on the time it takes for the light to weaken, and to count the number of underwater plants by moving the measuring vessel along a designated river cross-section.

[0039] The depth adjustment rod includes a telescopic main rod that can extend vertically and a plurality of telescopic thin rods for mounting the scanning device. The telescopic main rod includes a telescopic part and a connecting part, and the telescopic thin rods are arranged at equal intervals on the connecting part of the telescopic main rod.

[0040] The transmitting module includes a linear LED light source and a rectangular shield. The rectangular shield is used to integrate the emission light source of the linear LED light source into a rectangular light field distribution with a width of B, where B is the pre-measured width of a single plant. The linear LED light source and the rectangular shield of the transmitting module are set on one side of the telescopic rod, and the CCD device of the receiving module is set on the other side of the telescopic rod. The CCD device is used to receive the red light emitted from the opposite side. The transmitting module and receiving module on two adjacent telescopic rods are combined to form a measurement group.

[0041] Based on the aforementioned automatic measuring mechanism, this invention also provides a method for measuring underwater plant density using an automatic measuring mechanism, combined with... Figures 1-5It includes the following steps:

[0042] S1: Use a depth sounder to perform sonar depth sounding to obtain the distance h from the surveying vessel to the vegetation in the river;

[0043] S2: Adjust the depth adjustment rod length to h;

[0044] S3: Start the survey vessel and move according to the set river cross section. The speed of the survey vessel is V0. During the movement of the survey vessel, the transmitting module of the survey group emits red light, and the receiving module receives the red light by the CCD device.

[0045] The transmitting module emits light through a linear LED light source, and then the emitted light source of the linear LED light source is integrated into a rectangular light field distribution with a width of B through a rectangular shield. This red light is received by the CCD device of the receiving module on the opposite telescopic rod after passing through the plant.

[0046] S4: Set the pre-measured width of a single plant to B, then the time of light intensity influence by passing through the plant is T = B / V0, the CCD device obtains light intensity D0, when it comes into contact with the plant during navigation, the light intensity decreases to D1, and after Δt time, it recovers to light intensity D0.

[0047] S5: When the diameter of the underwater plants is relatively uniform, when the object obstruction time Δt is 0.9T<Δt<1.1T, the central processing unit records that the measurement group passes through 1 plant; otherwise, it is considered a non-plant and no record is made.

[0048] S6: The central processing unit calculates the number of plants m based on the information from each measurement group obtained by the scanning device;

[0049] S7: Navigate sequentially to complete the count of plant counts in the cross-section, then move to the next cross-section to complete the count of plant counts in a certain area of ​​the river.

[0050] When encountering uneven plant distribution, the method adapts to this by increasing the number of measurement groups in the scanning device and dynamically adjusting the distance between the receiver and transmitter by installing a rangefinder at the lower end of the light source. Specifically, the dynamic adjustment of the distance between the telescopic rods means that the distance between the transmitter and receiver modules changes according to the different plant distributions in the measurement area. When the light signal from the receiver module is interrupted, the rangefinder installed at the lower end of the light source measures the distance and returns the measured distance L to the central processing unit. The length L+B is used as the distance between the transmitter and receiver modules, ensuring that there is only one plant in each group and preventing missed measurements of plants in the same row. The distance between the transmitter and receiver in each group is determined using this method to ensure accurate statistics of unevenly distributed plants.

[0051] When encountering turbulent water flow, the depth sounder can quickly adapt to changes in water depth by increasing its sampling frequency and the response speed of the depth adjustment rod, thus ensuring the accuracy of the measurement.

[0052] When encountering water with many impurities, the central processing unit (CPU) distinguishes between plants and impurities by analyzing the patterns and durations of light intensity reduction. For example, light intensity reduction caused by plants usually follows a specific pattern and duration, while light intensity changes caused by impurities are more random.

[0053] Therefore, this invention constructs an optical system based on optical methods. By recording the degree and time of the plant's influence on light intensity, it can automatically determine whether a plant is a plant, providing a brand-new method for plant quantity statistics. This method has significant advantages such as high degree of automation, small error, and wide applicability, and truly realizes large-scale, high-precision underwater plant density measurement.

Claims

1. An automatic underwater plant density measuring mechanism, characterized in that, Includes depth sounder, depth adjustment rod, scanning device, survey vessel and central processing unit; The depth sounder is installed on the survey vessel and is used to measure the water depth at the vegetation location in real time. The depth adjustment rod is used to automatically adjust its length according to the water depth being measured to ensure the optimal measurement position; The scanning device is located at the end of the depth adjustment rod and includes multiple measurement groups. Each measurement group includes a transmitting module and a receiving module. The transmitting module is used to emit red light, and the receiving module receives the red light by a CCD device. The central processing unit is used to determine whether the light intensity decreases or whether it is a plant, an impurity in the water, or a branch of a plant, based on the time it takes for the light intensity to decrease. By moving the measuring vessel along the cross section of the river, the number of underwater plants can be counted.

2. The underwater plant density automatic measuring mechanism according to claim 1, characterized in that, The emission module includes a linear LED light source and a rectangular shield. The rectangular shield is used to integrate the emission light source of the linear LED light source into a rectangular light field distribution with a width of B, where B is the pre-measured width of a single plant.

3. The underwater plant density automatic measuring mechanism according to claim 2, characterized in that, The depth adjustment rod includes a vertically extendable main rod and multiple telescopic thin rods for mounting the scanning device, with the telescopic thin rods arranged on the main rod.

4. The underwater plant density automatic measuring mechanism according to claim 3, characterized in that, The linear LED light source and rectangular shield of the transmitting module are set on one side of the telescopic rod, and the CCD device of the receiving module is set on the other side of the telescopic rod. The CCD device is used to receive the red light emitted from the opposite side. The transmitting module and receiving module on two adjacent telescopic rods are combined to form a measurement group.

5. The underwater plant density automatic measuring mechanism according to claim 3, characterized in that, The telescopic thin rods are arranged at equal intervals on the telescopic main rod.

6. A measurement method for an automatic underwater plant density measuring mechanism according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1: Obtain the distance h from the surveying vessel to the vegetation in the river using a depth sounder; S2: Adjust the depth adjustment rod length to h; S3: Start the survey vessel and move according to the set river cross section. The speed of the survey vessel is V0. During the movement of the survey vessel, the transmitting module of the survey group emits red light, and the receiving module receives the red light by the CCD device. S4: Set the pre-measured width of a single plant to B, then the time of light intensity influence by passing through the plant is T = B / V0, the CCD device obtains light intensity D0, when it comes into contact with the plant during navigation, the light intensity decreases to D1, and after Δt time, it recovers to light intensity D0. S5: When the object occlusion time Δt is 0.9T < Δt < 1.1T, the central processing unit records that the measurement group passes through 1 plant; otherwise, it is considered a non-plant and no record is made. S6: The central processing unit calculates the number of plants m based on the information from each measurement group obtained by the scanning device; S7: Navigate sequentially to complete the count of plant counts in the cross-section, then move to the next cross-section to complete the count of plant counts in a certain area of ​​the river.

7. The measurement method of the underwater plant density automatic measurement mechanism according to claim 6, characterized in that, In step S3, the emitting module emits light through a linear LED light source, and then the emitted light source of the linear LED light source is integrated into a rectangular light field distribution with a width of B through a rectangular shield. This red light is received by the CCD device of the receiving module after passing through the plants.

8. The measurement method of the underwater plant density automatic measurement mechanism according to claim 6, characterized in that, In step S3, when encountering uneven plant distribution, the uneven plant distribution is adapted by increasing the number of measurement groups of the scanning device and dynamically adjusting the distance between the receiving end and the transmitting end by installing a rangefinder at the lower end of the light source. The dynamic adjustment of the distance between the telescopic rods specifically means that the distance between the transmitting module and the receiving module changes according to the different plant distribution in the measurement area. When the light signal of the receiving module is interrupted, the rangefinder installed at the lower end of the light source measures the distance and returns the measured distance L data to the central processing unit. The length L+B is taken as the distance between the transmitting module and the receiving module.

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