A seed screening device and system for forestry engineering

Abstract

The present application relates to the technical field of screening equipment, in particular to a seed screening device and system for forestry engineering, comprising: acquiring a first screen image and a second screen image of the seed screening device; determining the degree of blockage according to the analysis of the diameter difference of the first screen image and the second screen image; determining the actual screening area of each screen hole by using the degree of blockage, and determining the screening area reduction by the difference between the theoretical screening area and the actual screening area; constructing a relationship function between the vibration frequency and the single collision duration according to the vibration frequency of the screen and the length of the line connecting the two endpoints of the fixed screen; correcting the single collision duration by using the screening area reduction to obtain the single corrected collision duration, taking the single corrected collision duration as the input of the relationship function to obtain the target vibration frequency, and adjusting the screen vibration frequency. The present application can accurately adjust the screen vibration frequency of the seed screening device in real time, so as to make the seed screening more accurate.

Description

Technical Field

[0001] This invention relates to the field of screening equipment technology, and specifically to a seed screening device and system for forestry engineering. Background Technology

[0002] Seed screening is a core pre-processing step in the modern forestry seed and seedling industry chain, and its quality directly affects the production of high-quality seedlings and the effectiveness of ecological restoration. With the rapid development of forestry and grassland seed and seedling work, seed screening technology has become a key link in ensuring seed and seedling quality. One step in forestry seed screening is multi-stage vibrating screen grading according to geometric dimensions. Specifically, different sized screens are used for multi-stage sieving, thereby removing branches, leaves, and stones while simultaneously screening the seeds based on their appearance.

[0003] However, seeds collected in forest areas often contain sticky or fibrous impurities such as resin lumps, seed wings, and insect-damaged debris, which form complex blockages on the screen surface. As the screening equipment operates for longer periods, these impurities tend to mix and adhere to the screen surface and sieve holes, thus affecting the screening efficiency. Summary of the Invention

[0004] To address the technical problem of low screening efficiency caused by impurities clogging existing seed screening equipment during operation, the present invention aims to provide a seed screening device and system for forestry engineering. The specific technical solution adopted is as follows:

[0005] One embodiment of the present invention provides a seed screening device for forestry engineering, including a memory and a processor, wherein the processor executes a computer program stored in the memory to perform the following process:

[0006] Acquire a first screen image and a second screen image of a seed screening device. The first screen image is the screen image when it is not affected by impurities clogging, and the second screen image is the screen image when it is affected by impurities clogging at the current moment.

[0007] Based on the analysis of the difference in sieving diameter using the first and second screen images, the degree of blockage of each screen hole at the current moment is determined.

[0008] The actual screening area of ​​each screen hole is determined by the degree of clogging of each screen hole, and the screening area reduction is determined by the difference between the theoretical screening area and the actual screening area.

[0009] Based on the vibration frequency of the screen and the length of the line connecting the two ends of the fixed screen, a relationship function between the vibration frequency of the screen and the duration of a single collision is constructed.

[0010] The single collision duration is corrected by reducing the screening area to obtain the corrected single collision duration. The corrected single collision duration is used as the input of the relational function to obtain the target vibration frequency at the current moment.

[0011] The target vibration frequency is sent to the actuator of the seed screening device to adjust the screen vibration frequency.

[0012] Further, the step of analyzing the difference in sieve diameter based on the first and second sieve images to determine the degree of clogging of each sieve hole at the current moment includes:

[0013] Threshold segmentation and matching processing is performed on the first screen image and the second screen image to obtain each screen hole region pair. The screen hole region pair is composed of the first screen hole region and the second screen hole region. The first screen hole region is located in the first screen image, and the second screen hole region is located in the second screen image.

[0014] For each pair of sieve aperture regions, determine the standard sieve diameter of the first sieve aperture region and the effective sieve diameter of the second sieve aperture region in the pair.

[0015] The degree of clogging of the corresponding sieve holes in the second sieve hole region is determined based on the difference between the effective sieve diameter and the standard sieve diameter.

[0016] Further, threshold segmentation is performed on the first and second screen images to obtain each screen aperture region, including:

[0017] Global threshold segmentation is performed on the first screen image and the second screen image respectively to obtain each first screen hole region of the first screen image and each undetermined screen hole region of the second screen image;

[0018] Each undetermined sieve aperture region is segmented based on a local threshold to obtain each second sieve aperture region of the second sieve image.

[0019] Further, determining the standard sieve diameter of the first sieve aperture region and the effective sieve diameter of the second sieve aperture region includes:

[0020] The outer contour of each first sieve area is fitted with a circle to obtain the diameter of each fitted circle, and the average value of the diameters of all fitted circles is taken as the standard sieve diameter of the first sieve area.

[0021] The diameter of the inscribed circle is obtained by drawing the largest inscribed circle over the second sieve aperture region, and is used as the effective sieving diameter of the second sieve aperture region.

[0022] Further, determining the actual screening area of ​​each sieve hole using the degree of clogging of each sieve hole includes:

[0023] For each sieve opening, the standard aperture is corrected using the degree of clogging of the sieve opening to obtain the effective aperture of the sieve opening. The standard aperture is determined by the equipment parameters of the seed screening equipment.

[0024] The maximum diameter of impurities is obtained by weighting the standard aperture using the aperture difference between different layers of screens. The aperture difference is negatively correlated with the maximum diameter of impurities, while the standard aperture is positively correlated with the maximum diameter of impurities.

[0025] The difference between the effective aperture and the maximum diameter of the impurity is taken as the target diameter. The circular area corresponding to the target diameter is determined using the principle of circular area calculation, and then used as the actual screening area of ​​the sieve aperture.

[0026] The target diameter corresponding to the theoretical screening area is equal to the difference between the standard aperture and the maximum diameter of the impurity.

[0027] Furthermore, the step of constructing a relationship function between the vibration frequency of the screen and the duration of a single collision, based on the vibration frequency of the screen and the length of the line connecting the two endpoints of the fixed screen, includes:

[0028] The reciprocating vibration speed of the screen is determined based on the vibration frequency of the screen and the length of the line connecting the two ends of the fixed screen.

[0029] A relationship function between vibration frequency and single collision duration is constructed by using the seed falling distance, the movement speed, and the duration of a single collision.

[0030] Further, determining the reciprocating vibration speed of the screen based on the vibration frequency of the screen and the length of the line connecting the two endpoints of the fixed screen includes:

[0031] The reciprocal of the vibration frequency is used as the duration of a single vibration, and the distance of a single vertical vibration is determined based on the angle between the screen and the horizontal direction and the distance between the two endpoints.

[0032] The reciprocating vibration speed of the screen is obtained based on the single vertical vibration distance and the single vibration duration.

[0033] Furthermore, the step of constructing a relationship function between the vibration frequency and the duration of a single collision using the seed's falling distance, the movement speed, and the duration of a single collision includes:

[0034] Based on the fact that the sum of the running distance of the screen and the falling distance of the seed is equal to twice the single vertical vibration distance, the relationship function between the vibration frequency and the single collision duration is obtained, where the running distance is equal to the product of the motion speed and the single collision duration.

[0035] Further, the step of correcting the single collision duration using the reduction in screening area to obtain the corrected single collision duration includes:

[0036] The reduction in screening area is normalized by negative correlation to obtain the duration correction coefficient;

[0037] The duration correction coefficient and the single collision duration are combined to obtain the single collision correction duration.

[0038] Another embodiment of the present invention provides a seed screening system for forestry engineering, comprising:

[0039] The image acquisition module is used to acquire a first screen image and a second screen image of the seed screening device. The first screen image is the screen image when it is not affected by impurities clogging, and the second screen image is the screen image when it is affected by impurities clogging at the current moment.

[0040] The image processing module is used to analyze the aperture difference based on the first screen image and the second screen image to determine the degree of blockage of each screen hole at the current moment; to determine the actual screening area of ​​each screen hole based on the degree of blockage of each screen hole; and to determine the screening area reduction based on the difference between the theoretical screening area and the actual screening area, wherein the screening area is the number of times the seeds collide with the screen.

[0041] The function construction module is used to construct a function relating the vibration frequency of the screen to the duration of a single collision, based on the vibration frequency of the screen and the length of the line connecting the two endpoints of the fixed screen.

[0042] The frequency acquisition module is used to correct the single collision duration by reducing the screening area to obtain the corrected single collision duration, and to use the corrected single collision duration as the input of the relational function to obtain the target vibration frequency at the current moment.

[0043] The frequency adjustment module is used to send the target vibration frequency to the actuator of the seed screening equipment for adjusting the screen vibration frequency.

[0044] The present invention has the following beneficial effects:

[0045] This invention provides a seed screening device and system for forestry engineering. Compared to traditional manual inspection or fixed-cycle cleaning, it uses image recognition to identify the degree of clogging and adjusts the vibration frequency in real time. This can avoid the reduction in screening efficiency caused by screen clogging to a certain extent, ensuring the high efficiency of the seed screening process, improving the production efficiency of high-quality seedlings, and thus enhancing the effectiveness of ecological restoration. Compared to blindly increasing the frequency when clogging occurs, by determining the reduction in screening area and constructing a relationship function between vibration frequency and single collision duration, precise adjustment of the screen vibration frequency and precise control of energy consumption can be achieved, making seed screening more accurate, effectively removing unqualified impurities and poor seeds, and improving seed quality. Compared to the excessively high frequency of traditional methods that leads to excessive particle collision energy, adjusting the single collision duration can reduce the breakage rate to a certain extent and protect the integrity of the seeds.

[0046] Throughout the implementation process, machine vision technology, sensor data processing, and related algorithm models were employed to achieve intelligent and automated seed screening, reducing manual intervention, labor intensity, and labor costs, while improving the consistency and stability of screening. This invention can adaptively adjust according to the characteristics of different seeds and the actual situation of screen blockage, and has strong versatility and adaptability, and can be widely applied to various forestry engineering seed screening scenarios. Attached Figure Description

[0047] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 An execution flowchart of a seed screening device for forestry engineering is provided as an embodiment of the present invention;

[0049] Figure 2 This is a flowchart illustrating the implementation of step S2 in an embodiment of the present invention;

[0050] Figure 3 This is a flowchart illustrating the implementation of step S3 in an embodiment of the present invention;

[0051] Figure 4 This is a flowchart illustrating the implementation of step S4 in an embodiment of the present invention;

[0052] Figure 5 This is a flowchart illustrating the implementation of step S5 in an embodiment of the present invention. Detailed Implementation

[0053] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the specific implementation methods, structures, features, and effects of the technical solution proposed according to the present invention are described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0055] The application scenarios targeted by this invention can be:

[0056] In forestry engineering, seeds collected from forests often contain sticky or fibrous impurities such as resin lumps, seed wings, and insect-damaged debris. During vibration screening, these impurities, due to their own stickiness or mutual mixing, easily mix and adhere to the screen surface and sieve holes over extended periods, thus affecting the screening efficiency. The greater the screen blockage, the worse the effect of a single seed screening; to achieve better screening results, more screening cycles are required. Therefore, this invention analyzes the screen blockage to target the vibration frequency, thereby adjusting the screen vibration frequency.

[0057] The number of screening times refers to the number of times the seed comes into contact with the sieve to achieve the screening effect, that is, how many times the seed vibrates on the sieve to achieve the screening effect.

[0058] One embodiment of the present invention provides a seed screening device for forestry engineering, including a memory and a processor, wherein the processor executes a computer program stored in the memory to perform the following process:

[0059] Acquire the first screen image and the second screen image of the seed screening device. The first screen image is the screen image when it is not affected by impurities clogging, and the second screen image is the screen image when it is affected by impurities clogging at the current moment.

[0060] Based on the analysis of the difference in screening diameter using the first and second screen images, the degree of blockage of each screen hole at the current moment is determined.

[0061] The actual screening area of ​​each screen hole is determined by the degree of clogging of each screen hole, and the screening area reduction is determined by the difference between the theoretical screening area and the actual screening area.

[0062] Based on the vibration frequency of the screen and the length of the line connecting the two ends of the fixed screen, a relationship function between the vibration frequency of the screen and the duration of a single collision is constructed.

[0063] The single collision duration is corrected by reducing the screening area to obtain the corrected single collision duration. The corrected single collision duration is used as the input of the relational function to obtain the target vibration frequency at the current moment.

[0064] The target vibration frequency is sent to the actuator of the seed screening equipment for adjustment of the screen vibration frequency.

[0065] The following is a detailed explanation of each of the above steps:

[0066] refer to Figure 1 The diagram illustrates an execution flowchart of a seed screening device for forestry engineering according to an embodiment of the present invention, including the following processes:

[0067] S1, acquire the first and second screen images of the seed screening device.

[0068] Here, the first screen image is the screen image when it is not affected by impurities clogging, and the second screen image is the screen image when it is affected by impurities clogging at the current moment.

[0069] To facilitate the analysis of the degree of clogging of the screen holes during the operation of the seed screening equipment, this embodiment needs to acquire a first screen image after cleaning and a second screen image acquired during the operation interval for the analysis of the degree of clogging.

[0070] Specifically, an industrial camera is installed directly above the screen. It's important to maintain a certain distance between the camera and the screen to prevent impurities from contaminating the camera lens and affecting the quality of the captured images. Images of the screen after cleaning are captured by the industrial camera and recorded as the first screen image. Images of the screen during periods of intermittent operation are recorded as the second screen image.

[0071] Thus, this embodiment has obtained a first screen image and a second screen image for analyzing the degree of screen pore blockage.

[0072] S2, based on the first screen image and the second screen image, analyze the difference in aperture to determine the degree of blockage of each screen aperture at the current moment.

[0073] Here, the degree of clogging refers to the extent to which the various sieve holes on the screen are adhered to by sticky or fibrous impurities such as mixed resin blocks, seed wings, and insect-bored debris.

[0074] As an exemplary implementation, step S2 described above can be achieved through... Figure 2 Steps S201 to S203 shown are implemented as follows:

[0075] S201, threshold segmentation and matching processing are performed on the first screen image and the second screen image to obtain pairs of screen hole regions.

[0076] Here, the sieve aperture region is composed of a first sieve aperture region and a second sieve aperture region. The first sieve aperture region is located in the first sieve image, and the second sieve aperture region is located in the second sieve image. The sieve aperture region is the sieve aperture connected domain.

[0077] Specifically, threshold segmentation is first performed on the first screen image and the second screen image to obtain each first screen hole region of the first screen image and each second screen hole region of the second screen image; then, matching analysis is performed on each first screen hole region and each second screen hole region to obtain each screen hole region pair.

[0078] As an example, threshold segmentation is performed on the first screen image and the second screen image to obtain each first screen aperture region of the first screen image and each second screen aperture region of the second screen image, including:

[0079] The first step is to use the Otsu method to perform global threshold segmentation on the first screen image and the second screen image respectively, to obtain each first screen hole region of the first screen image and each undetermined screen hole region of the second screen image.

[0080] Of course, Hough circle detection can also be used for threshold segmentation. For global threshold segmentation, this embodiment does not limit the specific implementation method. The implementation process of threshold segmentation is existing technology and is not within the scope of protection of this invention, so it will not be described in detail here.

[0081] The second step is to perform local threshold segmentation on each region of the undetermined sieve hole to obtain each region of the second sieve hole in the second sieve image.

[0082] Because the second screen image is affected by impurities and blockage, its screen hole area has irregular features. In order to ensure the accuracy of the determined screen hole area, that is, to accurately obtain the shape of the blocked screen hole, it is necessary to perform local threshold segmentation again based on the screen hole area to be determined.

[0083] Specifically, for each undetermined sieve hole region, the minimum bounding rectangle of the undetermined sieve hole region is constructed. The original region image corresponding to the undetermined sieve hole region is obtained in the second sieve image by using the chain code of the minimum bounding rectangle. For the original region image, threshold segmentation is performed using the Otsu method to obtain the precise connected components of the sieve holes, which are used as the second sieve hole region.

[0084] S202, for each pair of sieve aperture regions, determine the standard sieve diameter of the first sieve aperture region and the effective sieve diameter of the second sieve aperture region in the pair of sieve aperture regions.

[0085] Here, the standard sieve diameter refers to the sieve diameter of each sieve opening on the same sieve in the first sieve image, which is essentially the number of pixels. All sieve openings on the same sieve have the same standard sieve diameter. The effective sieve diameter refers to the sieve diameter of each sieve opening on the same sieve in the second sieve image, which is also essentially the number of pixels. The second sieve image is a sieve image affected by impurities clogging it; therefore, the sieve diameter of the second sieve image is the effective sieve diameter. The effective sieve diameters of different sieve openings on the same sieve may be different.

[0086] In this embodiment, the outer contour of each first screen hole region is fitted with a circle to obtain the diameter of each fitted circle. Since the diameter of the screen holes is consistent when not affected by impurities, the average diameter of all fitted circles is taken as the standard screening diameter of the first screen hole region to avoid errors. The second screen hole region represents the area where the screen holes are attached to impurities. It is not a standard circle. Since the screening effect depends on the minimum diameter of the second screen hole region, the diameter of the inscribed circle is obtained by drawing the maximum inscribed circle of the second screen hole region, which is taken as the effective screening diameter of the second screen hole region.

[0087] S203, based on the difference between the effective screening diameter and the standard screening diameter, determine the degree of clogging of the corresponding screen holes in the second screen hole area.

[0088] When impurities adhere to the sieve openings, they gradually become clogged, causing the sieve opening area to shrink. The smaller the sieve opening area, the more severe the clogging. Since the sieve openings function as separators, the smaller the sieve opening diameter, the more severe the clogging. Therefore, a quantitative analysis of the degree of sieve clogging is conducted.

[0089] As an example, the formula for calculating the degree of clogging of the i-th sieve hole can be:

[0090] In the formula, E i d represents the degree of clogging of the i-th sieve hole. i d0 represents the effective screening diameter of the second sieve area corresponding to the i-th sieve hole, and d0 represents the standard screening diameter of the first sieve area.

[0091] In the formula for calculating the degree of congestion, This indicates the magnitude of the effective screening diameter compared to the standard screening diameter. The larger the value, the larger the effective screening diameter, and the less affected the screen openings are by impurities clogging them. With the degree of congestion E i A negative correlation is shown, that is The larger E is i The smaller; because d i ≤d0 so The value ranges from 0 to 1, and can be used... Implement negative correlation processing, and As a measure of the degree of clogging of the sieve holes.

[0092] Another example is that the formula for calculating the degree of clogging of the i-th sieve hole can be:

[0093] E i =norm(d0-d i In the formula, norm represents the linear normalization function.

[0094] In the formula for calculating the degree of congestion, d0-d i The larger the value, the greater the difference between the effective screening diameter and the standard screening diameter. This means the effective screening diameter is more susceptible to clogging by impurities, resulting in greater clogging of the screen openings. Therefore, d0-d i With E i A positive correlation is shown, with the difference in screening diameter d0-d i The larger the value, the greater the degree of congestion E. i The larger.

[0095] Referring to the calculation method for the clogging degree of the i-th sieve hole mentioned above, determine the clogging degree of each sieve hole.

[0096] The degree of clogging of each sieve hole in the same sieve can be used to determine the overall clogging degree of the sieve by taking the average of the clogging degrees of all sieve holes in the same sieve. This average can be used to determine the actual screening area in the subsequent screening process.

[0097] It should be noted that if the overall clogging of the screen is severe, that is, if the clogging degree is greater than or equal to the preset clogging threshold, then there is no need to adjust the vibration frequency afterward, and the screen needs to be cleaned directly.

[0098] It should also be noted that while increasing the vibration frequency can alleviate clogging in the short term, it may cause seed damage and equipment wear. In this embodiment, the multiple collision screening through gradual separation is safer and more reliable. That is, the fundamental solution is to intelligently adjust the vibration parameters according to the actual clogging situation of the screen.

[0099] Thus, this embodiment obtains the degree of clogging for each sieve hole used to represent the screening effect.

[0100] S3, determine the actual screening area of ​​each screen hole by using the degree of clogging of each screen hole, and determine the screening area reduction by the difference between the theoretical screening area and the actual screening area.

[0101] Here, screening area refers to the area occupied by the falling holes when impurities or seeds are screened, and can also represent the total number of collisions with the screen. Screening area reduction indicates the loss of effective screening area due to impurity blockage, which is essentially the attenuation of the functional area of ​​the screen that actually participates in material separation.

[0102] By analyzing the degree of screen clogging, the actual screening area of ​​each screen opening can be calculated, thus determining the reduction in screening area. This is because clogging reduces the usable screening area, thereby affecting screening efficiency. Therefore, to make the evaluation of screen efficiency during screening more accurate and real-time, it is necessary to determine the reduction in screening area.

[0103] As an exemplary implementation, step S3 described above can be achieved through... Figure 3 Steps S301 to S303 shown are implemented as follows:

[0104] S301, for each sieve hole, the standard aperture is corrected by the degree of sieve hole blockage to obtain the effective aperture of the sieve hole.

[0105] Here, aperture refers to the diameter of the sieve opening. The standard aperture is determined by the equipment parameters of the seed screening equipment, and its unit size can be millimeters. It is somewhat different from the standard screening diameter mentioned above because the standard screening diameter is composed of pixels obtained from the first screening image and the second screening image.

[0106] As an example, the formula for calculating the effective aperture of a sieve can be:

[0107] d i ′ =d a ×(1-E i In the formula, d i ' represents the effective aperture of the i-th sieve aperture, d a E represents the standard aperture. i This indicates the degree of clogging of the i-th sieve hole.

[0108] In the formula for calculating the effective aperture, E i The value of d ranges from 0 to 1, so the effective aperture d i ′ Less than or equal to the standard aperture d a The effective aperture represents the diameter of the sieve aperture after being affected by clogging, and its unit is millimeters. The degree of clogging is E. i The larger the aperture, the smaller the effective aperture of the sieve.

[0109] S302 uses the difference in aperture between different layers of screens to weight the standard aperture to obtain the maximum diameter of impurities.

[0110] When screening seeds, the screening efficiency is directly proportional to the sieve aperture diameter. The closer the aperture diameter of the impurities or defective seeds to be screened out is to that of the sieve aperture, the smaller the effective screening point. The greater the degree of clogging of the sieve, the smaller the area of ​​the effective screening point, exhibiting a square relationship overall. Therefore, the aperture difference in multi-layer screening is considered first. In this embodiment, a 20% aperture difference is used as an example for calculation, meaning that each layer of sieve apertures can remove impurities and defective seeds smaller than 20% of the aperture diameter.

[0111] As an example, the formula for calculating the maximum diameter of an impurity can be:

[0112] d z =d a ×(1-Δd); where d z The maximum diameter of the impurity is represented by d. a Δd represents the standard aperture, and Δd represents the aperture difference.

[0113] It should be noted that since the device in this embodiment is a multi-layer screening device, the maximum diameter of impurities that the screen can screen out is determined by the aperture difference. The implementer can also limit the value of the maximum diameter of impurities according to the specific actual situation, but no specific limit is made here.

[0114] S303 uses the difference between the effective aperture and the maximum diameter of the impurity as the target diameter, and uses the principle of circle area calculation to determine the circle area corresponding to the target diameter as the actual screening area of ​​the sieve aperture.

[0115] As an example, the formula for calculating the actual screening area of ​​the sieve aperture can be:

[0116] In the formula, S i d represents the actual screening area of ​​the i-th sieve aperture. i d represents the effective aperture of the i-th sieve aperture. z This indicates the maximum diameter of the impurity; the maximum diameter of impurities on the same sieve has the same numerical value.

[0117] S304, and so on, determine the theoretical screening area through steps S301 to S303.

[0118] As an example, the formula for calculating the theoretical screening area can be:

[0119] In the formula, S a d represents the theoretical screening area. a Indicates the standard aperture, d z This indicates the maximum diameter of the impurity, and the theoretical screening area of ​​each sieve hole in the same sieve is the same.

[0120] S305 determines the reduction in screening area by the difference between the theoretical screening area and the actual screening area.

[0121] Determining the reduction in screening area not only quantifies the physical impact of screen clogging, but also provides a key input for subsequent vibration frequency adjustment, thereby achieving adaptive optimization of the entire scheme.

[0122] As an example, the formula for calculating the reduction in sieve area can be:

[0123] In the formula, K i S represents the reduction in the screening area of ​​the i-th sieve aperture. a S represents the theoretical screening area. i This represents the actual screening area of ​​the i-th sieve hole.

[0124] Another example is the formula for calculating the reduction in sieve area:

[0125] K i =S a -S i ;

[0126] The reduction in screening area of ​​all screen openings in the same screen is accumulated and calculated to analyze the impact of impurity blockage on the entire screen, so as to correct the duration of a single collision and obtain the final reduction in screening area, denoted as K.

[0127] Of course, there is also the option of using the average degree of clogging of all sieve openings as the effective aperture for the entire sieve mesh, and its expression can be:

[0128] d = d a ×EV; where d represents the effective aperture of the sieve, and EV represents the degree of clogging of the sieve apertures of the entire sieve, that is, the average degree of clogging of all sieve apertures in the same sieve.

[0129] After determining the effective aperture, the actual screening area and the theoretical screening area are obtained. Then, the difference between the actual screening area and the theoretical screening area is analyzed to determine the screening area reduction. At this time, the determined screening area reduction is the effective screening area loss of the entire screen, which can also be directly used in the calculation and analysis of the subsequent step S5.

[0130] Thus, this embodiment obtains the reduction in screening area, which can directly reflect the loss of screening capacity caused by blockage.

[0131] S4. Based on the vibration frequency of the screen and the length of the line connecting the two ends of the fixed screen, construct the relationship function between the vibration frequency of the screen and the duration of a single collision.

[0132] In the adaptive control scheme of seed screening equipment, constructing the relationship function between the screen vibration frequency and the duration of a single collision is the core link connecting the physical model and the control logic. This relationship function transforms vibration parameters into particle dynamics behavior, providing a theoretical basis for subsequent frequency correction based on the degree of blockage.

[0133] When seeds are projectiles on the sieve, for ease of calculation, the horizontal motion of the seeds is considered as constant velocity, and the vertical motion of the seeds is considered as downward gravitational motion. The number of collision screenings is adjusted by judging the collision time of the seeds with the sieve during a single fall.

[0134] Since the movement of seeds in the horizontal direction is considered to be constant speed, the time points from when the seeds enter the sieve to when they leave the sieve are fixed. Only the average collision and screening time between the seeds and the sieve needs to be adjusted.

[0135] As an exemplary implementation, step S4 described above can be achieved through... Figure 4 Steps S401 to S402 shown are implemented as follows:

[0136] S401, the reciprocating vibration speed of the screen is determined based on the vibration frequency of the screen and the length of the line connecting the two ends of the fixed screen.

[0137] Specifically, the reciprocal of the vibration frequency is used as the duration of a single vibration, and the distance of a single vertical vibration is determined based on the angle between the screen and the horizontal direction and the distance between the two endpoints; the reciprocating vibration speed of the screen is obtained based on the distance of the single vertical vibration and the duration of the single vibration.

[0138] First, the expression for the duration of a single vibration is determined as follows: t g Let L represent the duration of a single vibration, and f represent the vibration frequency. Then, by obtaining the line length between the two endpoints of the fixed screen and the angle between the screen and the horizontal direction through design parameters, a sine function is used to obtain the distance of a single vertical vibration in the vertical direction during screen vibration. Its expression can be: L g =L×sinθ; where L g Let L represent the distance of a single vertical vibration, and L represent the length of the line connecting the two endpoints of the fixed screen. The two endpoints refer to the limiting points of the screen's movement, i.e., the two extreme points of vibration. The length of the line connecting these two extreme points is the distance between them. θ represents the angle between the screen and the horizontal direction. Finally, the reciprocating vibration velocity of the screen is determined by the relationship between distance, duration, and velocity. Its expression can be: In the formula, v represents the velocity of motion, and L g t represents the distance of a single vertical vibration. g Indicates the duration of a single vibration.

[0139] S402 constructs a relationship function between vibration frequency and single collision duration by using the seed falling distance, movement speed, and single collision duration.

[0140] Since the seed's initial movement during each projection contacts the screen, and the screen is at the farthest point of vibration, the vertical distance the screen travels and the seed falls during the period from the seed's initial movement to its next contact with the screen equals twice the distance of a single vertical vibration. Therefore, the expression vt + h = 2L is obtained. g .

[0141] Specifically, based on the fact that the sum of the running distance of the screen and the falling distance of the seed is equal to twice the single vertical vibration distance, the relationship function between the vibration frequency and the single collision duration is obtained, and the running distance is equal to the product of the motion speed and the single collision duration.

[0142] Since the seed undergoes uniformly accelerated motion due to gravity in the vertical direction, the relationship between its falling distance and time can be determined by the seed's weight, and its expression can be: In the formula, h represents the distance the seed falls, g represents the acceleration due to gravity, and t represents the duration of a single collision.

[0143] In summary, the expression vt + h = 2L g Simplification, based on as well as get Furthermore, by rearranging the equations, the relationship between vibration frequency and duration of a single collision can be obtained, and its expression can be:

[0144]

[0145] It should be noted that by using the relationship function between vibration frequency and single collision duration, vibration parameters can be transformed into modifiable particle dynamics indices, thus establishing the mathematical model basis for blockage compensation.

[0146] Thus, this embodiment obtains the relationship function between vibration frequency and single collision duration.

[0147] S5, the single collision duration is corrected by reducing the screening area to obtain the single corrected collision duration, and the single corrected collision duration is used as the input of the relational function to obtain the target vibration frequency at the current moment.

[0148] The vibration frequency of the screen is adjusted by using the relationship function between the vibration frequency and the duration of a single collision, as well as the reduction in screening area.

[0149] As an exemplary implementation, step S5 described above can be achieved through... Figure 5 Steps S501 to S503 shown are implemented as follows:

[0150] S501, the reduction in screening area is normalized by negative correlation to obtain the time correction coefficient.

[0151] Specifically, the reciprocal of the reduction in screening area is used as the time correction coefficient. Under normal circumstances, the reduction in screening area is not zero. If there is an extreme case, a non-zero constant, such as 0.01, can be added to the denominator of the fraction.

[0152] S502 combines the duration correction coefficient and the single collision duration to obtain the single collision correction duration.

[0153] In this embodiment, the default vibration frequency is first obtained, then the duration of a single collision is obtained, and the duration of a single collision is corrected using a duration correction coefficient to obtain the corrected duration of a single collision.

[0154] As an example, the formula for calculating the duration of a single corrected collision can be:

[0155] In the formula, t e t represents the duration of a single corrected collision. s This indicates the duration of a single collision, and K represents the reduction in screening area under the current screen clogging level. This represents the duration correction factor.

[0156] In the formula for calculating the duration of a single corrected collision, the duration correction coefficient is a dimensionless data. The greater the reduction in screening area, the greater the severity of screen blockage. The shorter the duration of the single corrected collision should be to maintain a good screening effect. Therefore, the duration correction coefficient is positively correlated with the duration of a single corrected collision, while the reduction in screening area is negatively correlated with the duration of a single corrected collision.

[0157] S503 uses the duration of a single corrected collision as input to the relational function to obtain the target vibration frequency at the current moment.

[0158] In this embodiment, the duration of a single corrected collision is used as the aforementioned relational function. The independent variable is determined by the vibration frequency, which is then used as the target vibration frequency for adjusting the degree of screen blockage at the current moment.

[0159] Thus, this embodiment obtains the target vibration frequency of a screen at the current moment.

[0160] S6 sends the target vibration frequency to the actuator of the seed screening equipment for adjustment of the screen vibration frequency.

[0161] In this embodiment, when the vibration frequency control methods of different screens are different, a target vibration frequency can be determined for each screen. However, if different screens are all controlled by one actuator, the average of the target vibration frequencies of all screens can be used as the final vibration frequency to adjust the screen vibration frequency.

[0162] Another embodiment of the present invention provides a seed screening system for forestry engineering, comprising:

[0163] The image acquisition module is used to acquire the first screen image and the second screen image of the seed screening device. The first screen image is the screen image when it is not affected by impurities clogging, and the second screen image is the screen image when it is affected by impurities clogging at the current moment.

[0164] The image processing module is used to analyze the difference in screening diameter based on the first screen image and the second screen image, determine the degree of blockage of each screen hole at the current moment, determine the actual screening area of ​​each screen hole based on the degree of blockage of each screen hole, and determine the screening area reduction based on the difference between the theoretical screening area and the actual screening area.

[0165] The function construction module is used to construct a function relating the vibration frequency of the screen to the duration of a single collision, based on the vibration frequency of the screen and the length of the line connecting the two endpoints of the fixed screen.

[0166] The frequency acquisition module is used to correct the single collision duration by reducing the screening area to obtain the corrected single collision duration. The corrected single collision duration is used as the input of the relational function to obtain the target vibration frequency at the current moment.

[0167] The frequency adjustment module is used to send the target vibration frequency to the actuator of the seed screening equipment to adjust the screen vibration frequency.

[0168] In summary, this invention maintains screening efficiency, reduces energy consumption, and extends equipment lifespan under clogging conditions by dynamically adjusting the frequency, forming a fully closed-loop adaptive system of "perception-analysis-decision-execution." Specifically, this invention can monitor screen clogging in real time and automatically adjust screening parameters to avoid reduced screening efficiency due to screen clogging, ensuring the high efficiency of the seed screening process, improving the production efficiency of high-quality seedlings, and thus enhancing the effectiveness of ecological restoration. By accurately calculating the degree of screen clogging and screening increment, it achieves precise adjustment of parameters such as screen vibration frequency, making seed screening more accurate, effectively removing unqualified impurities and defective seeds, and improving seed quality. Utilizing machine vision technology, sensor data processing, and related algorithm models, it realizes the intelligent and automated seed screening process, reducing manual intervention, lowering labor intensity and labor costs, while improving the consistency and stability of screening. Adaptive adjustment based on the characteristics of different seeds and the actual situation of screen clogging has strong versatility and adaptability, and can be widely applied to various forestry engineering seed screening scenarios.

[0169] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A seed screening device for forestry engineering, characterized in that, Includes a memory and a processor, the processor being used to process instructions stored in the memory to implement the following process: Acquire a first screen image and a second screen image of a seed screening device. The first screen image is the screen image when it is not affected by impurities clogging, and the second screen image is the screen image when it is affected by impurities clogging at the current moment. Based on the analysis of the difference in sieving diameter using the first and second screen images, the degree of blockage of each screen hole at the current moment is determined. The actual screening area of ​​each screen hole is determined by the degree of clogging of each screen hole, and the screening area reduction is determined by the difference between the theoretical screening area and the actual screening area. Based on the vibration frequency of the screen and the length of the line connecting the two ends of the fixed screen, a relationship function between the vibration frequency of the screen and the duration of a single collision is constructed. The single collision duration is corrected by reducing the screening area to obtain the corrected single collision duration. The corrected single collision duration is used as the input of the relational function to obtain the target vibration frequency at the current moment. The target vibration frequency is sent to the actuator of the seed screening device to adjust the screen vibration frequency.

2. The seed screening device for forestry engineering according to claim 1, characterized in that, The step of analyzing the difference in sieving diameter based on the first and second screen images to determine the degree of clogging of each screen hole at the current moment includes: Threshold segmentation and matching processing is performed on the first screen image and the second screen image to obtain each screen hole region pair. The screen hole region pair is composed of the first screen hole region and the second screen hole region. The first screen hole region is located in the first screen image, and the second screen hole region is located in the second screen image. For each pair of sieve aperture regions, determine the standard sieve diameter of the first sieve aperture region and the effective sieve diameter of the second sieve aperture region in the pair. The degree of clogging of the corresponding sieve holes in the second sieve hole region is determined based on the difference between the effective sieve diameter and the standard sieve diameter.

3. The seed screening device for forestry engineering according to claim 2, characterized in that, Threshold segmentation is performed on the first and second screen images to obtain the various screen aperture regions, including: Global threshold segmentation is performed on the first screen image and the second screen image respectively to obtain each first screen hole region of the first screen image and each undetermined screen hole region of the second screen image; Each undetermined sieve aperture region is segmented based on a local threshold to obtain each second sieve aperture region of the second sieve image.

4. The seed screening device for forestry engineering according to claim 2, characterized in that, The determination of the standard sieve diameter of the first sieve area and the effective sieve diameter of the second sieve area includes: The outer contour of each first sieve area is fitted with a circle to obtain the diameter of each fitted circle, and the average value of the diameters of all fitted circles is taken as the standard sieve diameter of the first sieve area. The diameter of the inscribed circle is obtained by drawing the largest inscribed circle over the second sieve aperture region, and is used as the effective sieving diameter of the second sieve aperture region.

5. The seed screening device for forestry engineering according to claim 1, characterized in that, The method of determining the actual screening area of ​​each sieve hole by utilizing the degree of clogging of each sieve hole includes: For each sieve opening, the standard aperture is corrected using the degree of clogging of the sieve opening to obtain the effective aperture of the sieve opening. The standard aperture is determined by the equipment parameters of the seed screening equipment. The maximum diameter of impurities is obtained by weighting the standard aperture using the aperture difference between different layers of screens. The aperture difference is negatively correlated with the maximum diameter of impurities, while the standard aperture is positively correlated with the maximum diameter of impurities. The difference between the effective aperture and the maximum diameter of the impurity is taken as the target diameter. The circular area corresponding to the target diameter is determined using the principle of circular area calculation, and then used as the actual screening area of ​​the sieve aperture. The target diameter corresponding to the theoretical screening area is equal to the difference between the standard aperture and the maximum diameter of the impurity.

6. The seed screening device for forestry engineering according to claim 1, characterized in that, The step of constructing a relationship function between the vibration frequency of the screen and the duration of a single collision, based on the vibration frequency of the screen and the length of the line connecting the two endpoints of the fixed screen, includes: The reciprocating vibration speed of the screen is determined based on the vibration frequency of the screen and the length of the line connecting the two ends of the fixed screen. A relationship function between vibration frequency and single collision duration is constructed by using the seed falling distance, the movement speed, and the duration of a single collision.

7. A seed screening device for forestry engineering according to claim 6, characterized in that, The process of determining the reciprocating vibration speed of the screen based on the vibration frequency of the screen and the length of the line connecting the two endpoints of the fixed screen includes: The reciprocal of the vibration frequency is used as the duration of a single vibration, and the distance of a single vertical vibration is determined based on the angle between the screen and the horizontal direction and the distance between the two endpoints. The reciprocating vibration speed of the screen is obtained based on the single vertical vibration distance and the single vibration duration.

8. A seed screening device for forestry engineering according to claim 7, characterized in that, The function relating vibration frequency to single-collision duration, constructed by considering the seed's falling distance, its velocity, and the duration of a single collision, includes: Based on the fact that the sum of the running distance of the screen and the falling distance of the seed is equal to twice the single vertical vibration distance, the relationship function between the vibration frequency and the single collision duration is obtained, where the running distance is equal to the product of the motion speed and the single collision duration.

9. A seed screening device for forestry engineering according to claim 1, characterized in that, The step of correcting the single-collision duration by reducing the screening area to obtain the corrected single-collision duration includes: The reduction in screening area is normalized by negative correlation to obtain the duration correction coefficient; The duration correction coefficient and the single collision duration are combined to obtain the single collision correction duration.

10. A seed screening system for forestry engineering, comprising: The image acquisition module is used to acquire a first screen image and a second screen image of the seed screening device. The first screen image is the screen image when it is not affected by impurities clogging, and the second screen image is the screen image when it is affected by impurities clogging at the current moment. The image processing module is used to analyze the difference in screening diameter based on the first screen image and the second screen image, determine the degree of blockage of each screen hole at the current moment, determine the actual screening area of ​​each screen hole using the degree of blockage of each screen hole, and determine the screening area reduction by the difference between the theoretical screening area and the actual screening area. The function construction module is used to construct a function relating the vibration frequency of the screen to the duration of a single collision, based on the vibration frequency of the screen and the length of the line connecting the two endpoints of the fixed screen. The frequency acquisition module is used to correct the single collision duration by reducing the screening area to obtain the corrected single collision duration, and to use the corrected single collision duration as the input of the relational function to obtain the target vibration frequency at the current moment. The frequency adjustment module is used to send the target vibration frequency to the actuator of the seed screening equipment for adjusting the screen vibration frequency.

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