CN102353805B - Apparatus for measuring wind dispersal plant seed vertical sedimentation velocity and method thereof - Google Patents

Abstract

The invention relates to a device and a method for measuring the vertical settling velocity of wind-borne plant seeds. It is characterized in that it includes a seed vertical settling photoelectric detection device and a data processing display system. The seed vertical settling photoelectric detection device includes a seed release joint with a photoelectric detection system arranged on the top of the settling tube, at least one settling tube, at least one settling tube An intermediate joint with a photoelectric detection system, a seed collection bottle, and a support that keeps the entire device vertically stable, the seed release joint with a photoelectric detection system, and the intermediate joint with a photoelectric detection system are respectively clamped and matched with the settling tube, The collection bottle is located directly below the settling tube; the data processing and display system includes a microprocessor and an LCD display, and the photoelectric detection system is connected to the data processing and display system through a data transmission line, and the photoelectric detection system is powered by a constant current power supply. It has the advantages of high measurement accuracy, simple device, economical and practical, and easy operation.

Description

A device and method for measuring the vertical settling velocity of wind-borne plant seeds

technical field

The invention belongs to the technical field of photoelectric detection, and relates to a device and method for measuring the vertical sedimentation velocity of wind-borne plant seeds, in particular to a device and method for simultaneously measuring the vertical sedimentation velocity of weed seeds to different heights by using a photoelectric sensor.

Background technique

Wind dispersal is a common way for plant seeds to disperse. The wind dispersal of plant seeds is of great significance to the gene flow of plant populations, plant biogeography, and plant community succession, and the vertical sedimentation velocity of seeds is one of the important factors that determine their dispersal distance.

The seeds of wind-borne plants are generally small in size, light in weight, and have pappus, and are greatly affected by factors such as airflow and static electricity when they settle. Therefore, the measurement of the vertical settling velocity of wind-borne plant seeds needs to be carried out under the condition of no airflow interference, and it is usually necessary to measure the average velocity of different vertical falling heights at the same time. At present, it is mainly to use a stopwatch or a fast camera to record the time when the seeds settle to different heights, and calculate the average settlement speed of the seeds. China's invention patent application "method for measuring speed using wireless terminal and system for realizing the method (application number: 200610126530.6; publication number CN 1984248)" proposes a method for using wireless terminal to measure moving objects in the preview mode of the camera A system and method for measuring the velocity, which improves the accuracy, but this method is not suitable for measuring the settling velocity of weed seeds at the millimeter scale. China's invention patent application "Method and system for determining the free sedimentation of floc/sludge particles (application number: 200810222184.0; publication number CN 101672861A)" proposes a method of settling floc/sludge using a CCD camera equipped with a microscope lens The mud particles are continuously photographed, and the settling distance and time of the flocs/sludge shown in the photos are recorded, and the settling speed of the flocs/sludge is calculated. Because the maximum height of the weed seed sedimentation velocity measurement reaches 2 meters, and the sedimentation column of this method is only 0.35 meters, so the method device is not suitable for the determination of the weed seed sedimentation velocity. These methods all have the disadvantages of complex measuring devices and poor accuracy. More importantly, when measuring the vertical settling velocity of wind-borne plant seeds, it is necessary to minimize the interference of air flow disturbance on the seeds. The above methods must be carried out in an open environment, which is not suitable for the determination of wind-borne plant seed settling velocity.

Contents of the invention

Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a technical scheme of a device and method for measuring the vertical sedimentation velocity of wind-borne plant seeds, so as to solve the problem that simple and economical devices cannot be used in the prior art to determine the vertical velocity of wind-borne plant seeds. The problem of settling velocity.

The device for measuring the vertical settling speed of wind-borne plant seeds is characterized in that it includes a seed vertical settling photoelectric detection device and a data processing and display system, and the seed vertical settling photoelectric detection device includes a belt photoelectric detection device arranged at the top of the settling tube. The system's seed release joint, at least one settling tube, at least one intermediate joint with a photoelectric detection system, one seed collection bottle and a support that keeps the entire device vertically stable, the described seed release joint with a photoelectric detection system, The intermediate joints with the photoelectric detection system are snap-fitted with the settling tube respectively, and the collection bottle is located directly below the settling tube; the data processing and display system includes a microprocessor and an LCD display, and the photoelectric detection system communicates with the settling tube through a data transmission line. The data processing display system is connected, and the photoelectric detection system is powered by a constant current power supply.

The device for measuring the vertical settling velocity of wind-borne plant seeds is characterized in that the settling tube is a round or square stainless steel tube or an aluminum alloy tube.

The device for measuring the vertical settling velocity of wind-borne plant seeds is characterized in that the photoelectric detection system is composed of two PCB boards arranged opposite to each other and two slit plates arranged opposite to each other, and the two slit plates are arranged on On the inside of the two PCB boards, at least one photocell and at least one LED light source are arranged at intervals on the PCB board, and the photocell on one PCB board is set correspondingly to the LED light source on the other PCB board; the photocell on the two PCB boards The light signals from the LED light source on the PCB board in the opposite slit are respectively received through the slit on the side slit plate. The light plane formed by the LED light source on the two PCB boards through the slit is perpendicular to the settling tube, and the light plane The width is equal to the inner diameter of the settling tube.

The device for measuring the vertical settling velocity of wind-borne plant seeds is characterized in that the height of the slit is adjustable between 0.5 mm and 1.5 mm, and the length of the slit is equal to the inner diameter of the settling tube.

The device for measuring the vertical settling velocity of wind-borne plant seeds is characterized in that the lower end of the seed release joint with a photoelectric detection system is set as a bayonet that matches the shape of the settling tube, and the upper end is set as a funnel with a round hole in the middle Shaped seed release port; the upper and lower ends of the intermediate joint with photoelectric detection system are set as bayonets matching the shape of the settling tube.

The device for measuring the vertical settling velocity of wind-borne plant seeds is characterized in that the photoelectric detection system is respectively installed on the seed release joint with the photoelectric detection system and the intermediate joint with the photoelectric detection system.

The device for measuring the vertical settling velocity of wind-borne plant seeds is characterized in that the position of the slit of the photoelectric detection system installed on the seed release joint with photoelectric detection system and the position of the seed release joint with photoelectric detection system The lower edge of the funnel-shaped seed release port at the upper end is parallel, and the slit of the photoelectric detection system installed on the middle joint with photoelectric detection system is opened in the middle of the middle joint with photoelectric detection system, that is, the junction point of two adjacent settling tubes place.

A described method for measuring wind-borne plant seed vertical settling velocity is characterized in that it comprises the following steps:

1) According to the vertical sedimentation height to be measured, select a sedimentation tube of the corresponding length, and connect the seed vertical sedimentation photoelectric detection device;

2) Connect the above-mentioned seed vertical sedimentation photoelectric detection device with the data processing and display system with a data transmission line, turn on the power switch, and power on the system;

3) Use ceramic tweezers to place a single plant seed to be tested at the entrance of the seed release joint with a photoelectric detection system, and gently push the seed to make it fall vertically from the entrance;

可计算出种子的沉降平均速度，其中：

：为第

点时的平均速度，

：为起点到第点的高度差，测试前将实际高度差输入微处理系统内存，

为光电检测系统检测到的种子沉降到第

点的时间； When the plant seeds pass through the light path of the photoelectric detection system vertically, the light plane stably irradiated on the photocell is instantly blocked, causing the detection signal of the photocell to change, and the microprocessing system records the light intensity pulse signals generated when the seeds pass through the starting point and different heights , after amplification and comparison processing, the time required for the seeds to fall to different heights can be obtained , according to the formula

The average velocity of seed settling can be calculated, where:

: for the first

The average speed at point time,

: It is the height difference from the starting point to the first point, and input the actual height difference into the micro-processing system memory before the test,

The seeds detected by the photoelectric detection system settle to the first

point of time;

The micro-processing system calculates the average vertical sedimentation speed of seeds at different heights, and displays it on the LCD display;

4) Take back the seeds that fell into the seed collection bottle, repeat the measurement or save them for later use.

The beneficial effects of the present invention are:

1. In the present invention, a plurality of photocells and LED light sources are relatively staggered, and a light plane perpendicular to the seed settlement path is formed through slits. Each photocell can receive the light signal sent by the opposite LED light source through the slit, and the LED light plane It can cover the entire detection optical path, avoiding the blind area of the optical path during the falling process of plant seeds, greatly improving the sensitivity of the sensor and the success rate of measurement;

2. The seed release joint with the photoelectric detection system and the intermediate joint with the photoelectric detection system of the present invention have the effect of connecting the settling tube in addition to the effect of obtaining the light signal changes produced when the plant seeds pass through the optical path plane;

3. According to the size and shape of the plant seeds to be tested, settling tubes with different inner diameters and lengths and matching joints can be selected arbitrarily, and the speed of plant seeds settling and falling from different heights can be measured;

4. The present invention can connect multiple settling tubes through photoelectric detection joints, and simultaneously measure the speed when the same seed settles to different heights;

5. The photoelectric detection device for vertical seed settling of the present invention avoids the interference of external air flow disturbance and stray light on the measurement signal, provides an approximate ideal environment for laboratory testing of wind-borne plant seed settling velocity, accurate and reliable measurement results, and small repeated measurement errors;

6. A seed collection bottle is arranged below the device of the present invention, which is conducive to the collection and repeated measurement of weed seeds;

7. The data processing and display system of the device of the present invention converts the analog signal into a digital signal, and through software programming, the system is controlled by a key switch, and the same plant seed is visually displayed on the LCD display screen at the same time when it vertically settles to different heights. speed, and stored in memory;

8. The present invention does not require an expensive CCD camera device, has low requirements on the test environment, and greatly reduces the test cost;

9. Based on photoelectric detection technology, the present invention also has the advantages of high measurement accuracy, simple device, economical and practical, and easy operation.

Description of drawings

Fig. 1 is the structural representation of device of the present invention;

Fig. 2 is a schematic diagram of a seed release joint with a photoelectric detection device of the present invention;

3 is a schematic diagram of the internal optical path of the photoelectric detection system of the present invention;

Fig. 4 is a schematic diagram of an intermediate joint with a photoelectric detection device of the present invention;

Fig. 5 is a schematic cross-sectional view of the optical path structure in the device of the present invention;

Fig. 6 is a schematic diagram of one optical signal processing in the photoelectric detection system of the present invention;

Fig. 7 is a flow chart of the present invention for measuring the sedimentation velocity of seeds.

Detailed ways

Below in conjunction with accompanying drawing, the present invention will be further described:

A device for measuring the vertical settling speed of wind-borne plant seeds, comprising a seed vertical settling photoelectric detection device and a data processing and display system, the seed vertical settling photoelectric detection device includes a seed release joint 1 with a photoelectric detection system arranged on the top of the settling tube , at least 1 settling tube 2, at least 1 intermediate joint 3 with a photoelectric detection system, 1 seed collection bottle 4 and a support 5 that keeps the whole device vertically stable, the described seed release joint 1 with a photoelectric detection system, The intermediate connector 3 with the photoelectric detection system is engaged with the settling tube 2 respectively, and the collection bottle 4 is located directly below the settling tube 2; the data processing and display system includes a microprocessor 6 and an LCD display 7, and the photoelectric The detection system is connected with the data processing and display system through the data transmission line 8 , and the photoelectric detection system is powered by a constant current power supply 9 .

The settling tube 2 is a round or square stainless steel tube or an aluminum alloy tube with a smooth inner wall and no light transmission. Different tube diameters and lengths can be selected according to the size of the seeds and the measurement needs.

The photoelectric detection system is composed of two oppositely arranged PCB boards 12 and two oppositely placed slit boards, the two slit boards are arranged inside the two PCB boards 12, and at least one photocell is sequentially arranged on the PCB board 12 14 and at least one LED light source 15, the photocell 14 on one PCB board 12 is set corresponding to the LED light source 15 on the other PCB board 12; The slit 13 receives the light signal sent from the LED light source 15 on the PCB board in the opposite slit 13, the light plane formed by the LED light source 15 on the two PCB boards through the slit 13 is perpendicular to the settling tube 2, and the width of the light plane is equal to the settling tube 2 inner diameters; the height of the slit 13 is adjustable between 0.5 mm and 1.5 mm, and the length of the slit 13 is equal to the inner diameter of the settling tube 2; the photoelectric detection system is respectively installed on the seed release joint 1 with photoelectric detection system and with photoelectric detection on the middle joint 3 of the system.

Figure 6 shows one optical signal detection and processing circuit in the photoelectric detection system. According to the size of the seed, each PCB board can repeat several circuits to expand the test area, and the optical signal detection and processing circuit and the LED light source are arranged alternately. The circuit has the functions of signal detection, signal amplification, filtering and comparison. When the plant seeds fall through the detection device, the weak signal fluctuations generated by the photocell detection are amplified by the first operational amplifier, then filtered by the capacitor, and then passed through the second A high-level (5V power supply) pulse is output after comparison and processing by an operational amplifier. The pulse signal is input into the microprocessor, and then the settling speed of the weed seeds can be calculated through software programming, and it is directly displayed on the LCD display.

The lower end of the seed release joint 1 with a photoelectric detection system is set as a bayonet 10 matching the shape of the settling tube, and the upper end is set as a funnel-shaped seed release port 11 with a round hole in the middle; Both ends are set as bayonets matching the shape of the settling tube 2.

The position of the slit 13 of the photoelectric detection system installed on the seed release joint 1 with a photoelectric detection system is parallel to the lower edge of the funnel-shaped seed release port 11 at the upper end of the seed release joint 1 with a photoelectric detection system. The slit 13 of the photoelectric detection system on the intermediate joint 3 is opened in the middle of the intermediate joint 3 with the photoelectric detection system, that is, at the junction of two adjacent settling tubes 2 .

A method for measuring wind-borne plant seed vertical settling velocity, comprising the following steps:

1) According to the vertical sedimentation height to be measured, select a sedimentation tube of the corresponding length, and connect the seed vertical sedimentation photoelectric detection device;

2) Connect the above-mentioned seed vertical sedimentation photoelectric detection device with the data processing and display system with a data transmission line, turn on the power switch, and power on the system;

3) Use ceramic tweezers to place a single plant seed to be tested at the entrance of the seed release joint with a photoelectric detection system, and gently push the seed to make it fall vertically from the entrance;

，根据公式可计算出种子的沉降平均速度，其中：：为第

点时的平均速度，：为起点到第

点的高度差，测试前将实际高度差输入微处理系统内存，

为光电检测系统检测到的种子沉降到第点的时间； When the plant seeds pass through the light path of the photoelectric detection system vertically, the light plane stably irradiated on the photocell is instantly blocked, causing the detection signal of the photocell to change, and the microprocessing system records the light intensity pulse signals generated when the seeds pass through the starting point and different heights , after amplification and comparison processing, the time required for the seeds to fall to different heights can be obtained

, according to the formula The average velocity of seed settling can be calculated, where: : for the first

The average speed at point time, : from the starting point to the

point height difference, the actual height difference is input into the micro-processing system memory before the test,

is the time when the seeds detected by the photoelectric detection system settle to the first point;

The micro-processing system calculates the average vertical sedimentation speed of seeds at different heights, and displays it on the LCD display;

4) Take back the seeds that fell into the seed collection bottle, repeat the measurement or save them for later use.

The present invention can obtain the time required for the vertical settlement of plant seeds to a fixed height by collecting the pulse signal generated when the light source stably irradiated on the photocell is instantaneously blocked during the plant seed settlement process, and calculate the average settlement speed of plant seeds, which is useful for the study of weeds. Diffusion spread law provides a scientific basis.

The device of the present invention can measure the vertical settling velocity of wind-borne plant seeds with diameters of centimeters and millimeters, and has the advantages of high measurement accuracy, good stability, simple disassembly, and convenient portability, and is suitable for laboratory measurement and also suitable for Work in the field. The method of the invention has simple operation and stable measurement data, and can simultaneously measure the average speed of the same plant seed settling down from different heights.

Example 1 Determination of vertical sedimentation velocity of solidago canadensis seeds

1. Experimental method:

The measurement experimental device mainly consists of a seed release joint with a photoelectric detection system, a round stainless steel settling tube, an intermediate joint with a photoelectric detection system, a bracket, a seed collector, a microprocessor, an LCD display, a constant current Composed of power supply and data transmission line. The circular stainless steel settling tube has a diameter of 60 mm and a height of 1 meter. Three square photocells of 10mm×10mm are placed on each PCB of the photoelectric detection system, the model is SP-10A, DIP package and 3 SMD package white light LEDs, the power of the LED is 0.06W, 20mA, and the divergence angle is 120°. Arranged linearly and alternately with LEDs. The PCB board is placed behind the slit, the height of the slit is 1.0 mm, and the length is 60 mm; the LED light source passes through the slit to form a light plane perpendicular to the falling path of the plant seeds, and illuminates the photocell behind the same slit on the opposite side.

Use ceramic tweezers to pick up a single solidago canadensis seed, put it on the edge of the release port of the seed release joint, gently push the seed so that it enters the settling tube vertically from the release port, and when the seed falls into the seed collector, it will be displayed on the display average velocity of settlement.

Get the seeds back from the seed collection bottle, repeat the above experiment, repeat 5 times, and obtain the mean value and standard deviation of the same seed's sedimentation velocity.

2. Experimental results:

10 Solidago canadensis seeds were measured, each seed was measured 5 times, and the results are shown in Table 1 (unit: m/s).

Table 1 Measured average speed of solidago canadensis seed settling

Embodiment 2 Simultaneous measurement of the vertical settling velocity of the seeds of lettuce at different heights

1. Experimental method:

The measurement experimental device mainly consists of a seed release joint with a photoelectric detection system, 3 square stainless steel settling tubes, 3 intermediate joints with a photoelectric detection system, a bracket, a seed collection bottle, a microprocessor, an LCD display, and a constant current power supply , Composed of data transmission lines. The square stainless steel settling tubes have a side length of 30mm, each with a length of 0.5m, connected by an intermediate joint, and can simultaneously measure the settling velocity of the seeds at a settling height of 0.5m, 1m, and 1.5m.

Use ceramic tweezers to pick up a single mountain lettuce seed, put it on the edge of the release port of the seed release joint, lightly push the seed so that it enters the settling tube vertically from the release port, and when the seeds fall into the seed collector, they will be displayed on the display respectively The average settlement velocity when the settlement height is 0.5m, 1m and 1.5m.

Get the seeds back from the seed collection bottle, repeat the above experiment, repeat 5 times, and obtain the mean value and standard deviation of the same seed's sedimentation velocity.

2. Experimental results:

The seeds of 10 lettuces are measured, and each seed is measured 5 times, and the average velocity of sedimentation under different heights is shown in Table 2, Table 3 and Table 4 (unit: m/s);

Table 2 The average sedimentation velocity of lettuce seeds at a height of 0.5 meters

Table 3 The average speed of sedimentation of 1.0 meters of lettuce seeds

Table 4 The average speed of sedimentation of 1.5 meters of lettuce seeds

Experimental data shows that the repeated measurement deviation of the average velocity of the same seed settling by the present invention is small, indicating that the average velocity of vertical settling of grass seeds measured by the device and the method has high stability and good repeatability. There was no significant difference in the average velocity at different settling heights, indicating that the seeds settled at a uniform velocity after 0.5 m.

Claims (8)

1. A device for measuring wind-borne plant seed vertical settling velocity, characterized in that it includes a seed vertical settling photoelectric detection device and a data processing display system, and the described seed vertical settling photoelectric detection device includes a band photoelectric detection system arranged on the top of the settling tube The seed release joint, at least one settling tube, at least one intermediate joint with a photoelectric detection system, one seed collection bottle and a support to keep the whole device vertically stable, the described seed release joint with a photoelectric detection system, with The intermediate connectors of the photoelectric detection system are snap-fitted with the settling tubes respectively, and the collection bottle is positioned directly below the settling tubes; the data processing and display system includes a microprocessor and an LCD display, and the photoelectric detection system communicates with the data through a data transmission line. The processing display system is connected, and the photoelectric detection system is powered by a constant current power supply. 2. A device for measuring the vertical settling velocity of wind-borne plant seeds according to claim 1, characterized in that said settling tube is a round or square stainless steel tube or an aluminum alloy tube. 3. A kind of device for measuring wind-borne plant seed vertical settling velocity according to claim 1, it is characterized in that described photoelectric detection system is made up of two PCB boards arranged oppositely and two slit plates placed oppositely, two A slit plate is arranged on the inside of two PCB boards, and at least one photocell and at least one LED light source are arranged at intervals on the PCB board, and the photocell on one PCB board is set correspondingly to the LED light source on the other PCB board; The photocells on one PCB board respectively receive the light signals from the LED light source on the PCB board in the opposite slit through the slit on the side slit board, and the light plane formed by the LED light source on the two PCB boards through the slit and the The settling tube is vertical, and the width of the light plane is equal to the inner diameter of the settling tube. 4. A device for measuring the vertical settling velocity of wind-borne plant seeds according to claim 3, characterized in that the height of the slit is adjustable between 0.5 mm and 1.5 mm, and the length of the slit is equal to the inner diameter of the settling tube. 5. The device for measuring the vertical settling velocity of wind-borne plant seeds according to claim 1, characterized in that the lower end of the seed release joint with photoelectric detection system is set to a bayonet that matches the profile of the settling tube, and the upper end is set to A funnel-shaped seed release opening with a round hole in the middle; the upper and lower ends of the middle joint with a photoelectric detection system are set as bayonets matching the shape of the settling tube. 6. The device for measuring the vertical settling velocity of wind-borne plant seeds according to claim 3, wherein said photoelectric detection system is respectively installed on the seed release joint with photoelectric detection system and the intermediate joint with photoelectric detection system superior. 7. A kind of device for measuring wind-borne plant seed vertical settling velocity according to claim 6, is characterized in that the position of the slit of the photoelectric detection system installed on the seed release joint with photoelectric detection system is the same as the position of the slit with photoelectric detection system. The lower edge of the funnel-shaped seed release port at the upper end of the seed release joint of the detection system is parallel, and the slit of the photoelectric detection system installed on the middle joint with a photoelectric detection system is opened in the middle of the middle joint with a photoelectric detection system, that is, two phases At the junction point adjacent to the settling tube. 8. a method utilizing the device described in claim 1 to measure wind-borne plant seed vertical settling velocity, is characterized in that comprising the following steps: 1) According to the vertical sedimentation height to be measured, select a sedimentation tube of the corresponding length, and connect the seed vertical sedimentation photoelectric detection device; 2) Connect the above-mentioned seed vertical sedimentation photoelectric detection device with the data processing and display system with a data transmission line, turn on the power switch, and power on the system; 3) Use ceramic tweezers to place a single plant seed to be tested at the entrance of the seed release joint with a photoelectric detection system, and gently push the seed to make it fall vertically from the entrance; When the plant seeds pass through the light path of the photoelectric detection system vertically, the light plane stably irradiated on the photocell is instantly blocked, causing the detection signal of the photocell to change, and the microprocessing system records the light intensity pulse signals generated when the seeds pass through the starting point and different heights , after amplification and comparison processing, the time required for the seeds to fall to different heights can be obtained

, according to the formula

The average velocity of seed settling can be calculated, where:

: for the first

The average speed at point time,

: from the starting point to the

point height difference, the actual height difference is input into the micro-processing system memory before the test,

The seeds detected by the photoelectric detection system settle to the first

point of time; The micro-processing system calculates the average velocity of seeds vertically settling from different heights, and displays it on the LCD display; 4) Take back the seeds that fell into the seed collection bottle, repeat the measurement or save them for later use.

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