Plant spacing measurement method and system

Abstract

The present invention provides a plant spacing measurement method and system, which includes the following steps: S1, obtaining crop points in the area to be measured; S2, selecting a crop point as the starting crop point, determining a search area based on the position of the starting crop point, and using the crop points within the search area as the ending crop points; S3, performing a screening operation on the ending crop point based on the angle formed by the line segment formed by the starting crop point and the ending crop point relative to the preset crop row in which the starting crop point is located, to determine the adjacent crop points of the starting crop point in a set direction of the preset crop row, and calculating the distance between the starting crop point and the adjacent crop points; S4, repeating steps S2 to S3, traversing the crop points in the area to be measured, and performing plant spacing measurement operations on the crop points in the area to be measured. Through the present invention, the adjacent crops in the same crop row are accurately determined, and based on this, the plant spacing between crops is accurately measured.

Description

Technical Field

[0001] The present invention relates to the technical field of plant spacing detection, and in particular to a plant spacing measurement method and system. Background Art

[0002] In agricultural production, high crop yields require a high-quality population, and good individual crops are the foundation for improving the quality of super-high-yield populations. While many factors influence crop performance, one particularly important factor is the spacing and number of plants. This directly affects the light exposure of individual seedlings in the field and the distribution of light within the canopy, which in turn affects photosynthesis within the crop population and, consequently, crop yield.

[0003] Currently, the measurement of plant spacing and plant number of crops after sowing is mostly limited to manual measurement or approximate measurement. Manual measurement is time-consuming and labor-intensive, resulting in limited measurement scale and low measurement efficiency, while approximate measurement has low measurement accuracy and is unable to conduct large-scale statistics. In addition, there is a method for measuring the plant spacing and plant number of crops using drones and algorithms. However, in the process of measuring the plant spacing of crops based on this algorithm, it is easy to calculate the plant spacing based on individual crops in adjacent crop rows, and it is impossible to accurately identify individual crops in the same crop row, resulting in inaccurate plant spacing measurements. At the same time, during the sowing process, if multiple sowing or omission occurs, it will also affect the calculation of the plant spacing in the same crop row, and thus affect the accuracy of the measurement results.

[0004] In view of this, it is necessary to improve the existing crop spacing measurement method to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to solve the problem in the prior art of inaccurate plant spacing measurement results caused by the inability to accurately identify crops on the same crop row; at the same time, the occurrence of multiple sowing or missed sowing will also affect the accuracy of the plant spacing measurement results on the same crop row.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a plant spacing measurement method, comprising:

[0007] S1. Obtain crop points in the area to be measured;

[0008] S2. Select a crop point as the starting crop point, determine a search area based on the position of the starting crop point, and use the crop points within the search area as the ending crop points;

[0009] S3. Performing a screening operation on the ending crop point based on an angle formed by a line segment formed by the starting crop point and the ending crop point relative to the preset crop row where the starting crop point is located, to determine adjacent crop points of the starting crop point in a set direction of the preset crop row where the starting crop point is located, and calculating the distance between the starting crop point and the adjacent crop points;

[0010] S4. Repeat steps S2 to S3 to traverse the crop points in the area to be measured, so as to perform a plant spacing measurement operation on the crop points in the area to be measured.

[0011] As a further improvement of the present invention, step S1 includes:

[0012] Obtain orthophotos of the area to be measured;

[0013] The orthophoto image is detected using the target detection algorithm, and the crop is framed by a detection frame according to the crop size, with the center point of the detection frame as the crop point corresponding to the crop.

[0014] As a further improvement of the present invention, determining the search area according to the position of the starting crop point includes:

[0015] A straight line passing through the starting crop point and perpendicular to the preset crop row where the starting crop point is located is used as a dividing line, the area to be measured is divided by the dividing line, and the area in the set direction of the preset crop row where the starting crop point is located is used as the search area.

[0016] As a further improvement of the present invention, the screening operation on the ending crop point based on the angle formed by the line segment formed by the starting crop point and the ending crop point relative to the preset crop row where the starting crop point is located includes:

[0017] Connecting the end crop points respectively from the starting crop points to form a plurality of line segments, and determining angles formed between the line segments and the preset crop rows where the starting crop points are located;

[0018] The line segments are judged to be effective, so as to eliminate line segments with angles greater than a preset angle, obtain effective line segments and their number, and select an effective line segment as a target line segment based on the number of effective line segments and the size of the angle.

[0019] As a further improvement of the present invention, the preset angle includes a first preset angle and / or a second preset angle;

[0020] The first preset angle is a fixed value, and the second preset angle is a is the preset maximum distance between plants, and b is the length of the line segment.

[0021] As a further improvement of the present invention, the step of selecting a valid line segment as a target line segment based on the number of valid line segments and the size of the included angle includes:

[0022] Determine whether the number of valid line segments is less than a preset number;

[0023] If so, the valid line segment with the smallest angle with the preset crop row where the starting crop point is located is selected as the target line segment;

[0024] If not, two valid line segments with shorter lengths are selected from the valid line segments, and the target line segment is determined based on whether the length of the shortest valid line segment among the two valid line segments is less than a multiple of the length of the other valid line segment.

[0025] As a further improvement of the present invention, determining the target line segment based on whether the length of the shortest valid line segment of the two valid line segments is less than a multiple of the length of the other valid line segment includes:

[0026] Preset a parameter k and determine whether the shortest valid line segment length is less than another valid line segment length that is k times the parameter, 0<k<1;

[0027] If so, the shortest valid segment is selected as the target segment;

[0028] If not, the valid line segment with the smallest angle with the preset crop row where the starting crop point is located is selected as the target line segment;

[0029] Among them, the parameters c is the average value of the preset plant spacing, d is the average value of the preset row spacing, and e is the adaptation coefficient.

[0030] As a further improvement of the present invention, after selecting a valid line segment as a target line segment based on the number of valid line segments and the size of the included angle, the present invention further includes:

[0031] Determine whether the length of the target line segment is greater than the preset length;

[0032] If yes, the target line segment is deleted, and it is determined that no adjacent crop points of the starting crop point in the set direction of the preset crop row exist;

[0033] If not, the ending crop point corresponding to the target line segment is determined as the adjacent crop point of the starting crop point in the set direction of the preset crop row;

[0034] The preset length is the product of the empirical coefficient and the average length of the valid line segments.

[0035] As a further improvement of the present invention, after performing the plant spacing measurement operation on the crop points in the area to be measured, the method includes:

[0036] Calculate the mean and variance of the plant spacing of the crop points in the area to be measured.

[0037] In a second aspect, the present invention further discloses a plant spacing measurement system, comprising:

[0038] A detection unit, used to obtain crop points in the area to be measured;

[0039] The measuring unit is used to select a crop point as a starting crop point, determine a search area according to the position of the starting crop point, and use the crop points in the search area as ending crop points. Based on the angle formed by the line segment formed by the starting crop point and the ending crop point relative to the preset crop row where the starting crop point is located, a screening operation is performed on the ending crop point to determine the adjacent crop points of the starting crop point in a set direction of the preset crop row where the starting crop point is located, and calculate the distance between the starting crop point and the adjacent crop points, and traverse the crop points in the area to be measured to perform a plant spacing measurement operation on the crop points in the area to be measured.

[0040] As a further improvement of the present invention, it also includes:

[0041] The calculation unit is used to calculate the emergence rate of the area to be measured based on the spacing of the crop points in the area to be measured. The specific calculation formula of the emergence rate is as follows:

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051] Where x is the number of parent rows in the area to be measured, and y is the number of parent rows in the area to be measured.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The starting crop points are connected to the ending crop points to form several line segments, and the angles formed by the line segments and the preset crop rows where the starting crop points are located are determined. Based on the angles, the line segments are effectively judged to eliminate line segments with angles greater than the preset angle to avoid interference from crop points in other crop rows, thereby improving calculation accuracy; line segments with angles less than or equal to the preset angle are regarded as valid line segments, and different methods are selected to determine the target line segments based on whether the number of valid line segments is less than the preset number, thereby coping with the omission, over-seeding and offset of crop planting in the existing technology, so as to ensure the accurate determination of the adjacent crop points of the starting crop point in the set direction of the crop row; finally, the target line segment is judged again based on the empirical coefficient to further ensure the accuracy of the plant spacing. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A schematic diagram of the steps of a plant spacing measurement method shown in the present invention;

[0055] Figure 2 It is a schematic diagram of the orthophoto map of the area to be measured;

[0056] Figure 3 A schematic diagram of the crop points in the area to be measured;

[0057] Figure 4 Schematic diagram of the crop point arrangement on the crop row under ideal conditions, the crop point arrangement on the crop row under actual conditions, and the preset crop row where the starting crop point is located;

[0058] Figure 5 A schematic diagram showing the area to be measured being divided using a straight line passing through the starting crop point and perpendicular to the preset crop row where the starting crop point is located as a dividing line;

[0059] Figure 6 Schematic diagram of establishing a plane rectangular coordinate system of the area to be measured with vertex D2 as the origin;

[0060] Figure 7 for Figure 1 The schematic diagram of the specific steps included in step S3 shown;

[0061] Figure 8 A schematic diagram of several line segments formed by connecting the starting crop points to the ending crop points;

[0062] Figure 9 A schematic diagram of the specific steps involved in selecting a valid line segment as a target line segment based on the number of valid line segments and the size of the included angle;

[0063] Figure 10 for Figure 9 The schematic diagram of the specific steps included in step S323 is shown;

[0064] Figure 11 For Figure 9 A schematic diagram of the steps following the steps shown;

[0065] Figure 12 This is a schematic diagram showing that the number of valid line segments is less than the preset number when the preset number is 4;

[0066] Figure 13 A schematic diagram showing that when the preset number is 4, the number of valid line segments is greater than or equal to the preset number;

[0067] Figure 14 A schematic diagram of three points selected for multicasting;

[0068] Figure 15 This is a schematic diagram of selecting three points in the case of missed broadcast;

[0069] Figure 16 This is a schematic diagram of a situation when four points are selected;

[0070] Figure 17 This is a schematic diagram of another situation when four points are selected;

[0071] Figure 18 This is a topological diagram of the plant spacing measurement system shown in the present invention. DETAILED DESCRIPTION

[0072] The present invention is described in detail below with reference to the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in this field based on these embodiments are all within the scope of protection of the present invention.

[0073] Please refer to Figures 1 to 17 As shown, the present invention shows a specific implementation of a plant spacing measurement method. In this embodiment, the plant spacing measurement method can be applied to electronic devices, which may be, for example, terminals, servers, ground workstations, drones, etc. The terminal may be a smart phone, a tablet computer, a portable laptop computer, a desktop computer, etc. The drone may be a rotary-wing drone, a fixed-wing drone, etc. Among them, the rotary-wing drone is designed with multiple propellers above the fuselage, and the multiple propellers can generate powerful lift, so the operator can achieve precise control of the rotary-wing drone, while the fixed-wing drone needs to use auxiliary tools such as a runway or a catapult to achieve launch; and the rotary-wing drone can achieve hovering, while the fixed-wing drone cannot. Therefore, a rotary-wing drone is preferred to better achieve the beneficial effects disclosed by the present invention.

[0074] The application scenario of a plant spacing measurement method disclosed in this application is: when using a machine to plant crops on a certain plot of land, the planting parameters under ideal conditions will be pre-set inside the machine (planting parameters include: crop rows, plant spacing, and row spacing, etc.), so that the machine can sow the crops in sequence according to the set planting parameters. However, in actual conditions, due to uneven terrain, machine failure, etc., when crops are sown in sequence under actual conditions, there will be deviations from the crop rows in the ideal state. This application measures the plant spacing between crops planted in the same crop row under the actual state of the machine, and calculates the crop emergence rate based on this, so that subsequent users can evaluate the crop conditions of the plot.

[0075] Ginseng Figure 1 As shown, the plant spacing measurement method includes the following steps S1 to S4.

[0076] Step S1: Acquire crop points in the area to be measured.

[0077] For example, the operator controls the drone to fly over the area to be measured and photograph the area to obtain an orthophoto of the area. The orthophoto is then detected using an object detection algorithm, and crops are framed based on their size using a detection frame. The center of the detection frame is used as the corresponding crop point.

[0078] Specifically, the operator controls the remote control of the drone, or based on the flight control system installed on the drone itself, and realizes automatic control of the drone through electronic devices such as computers, and controls the drone to fly to a preset height above the area to be measured (for example, the preset height is 5 meters, 9 meters, etc.). The area to be measured is photographed by a camera unit installed on the drone to obtain an orthophoto of the area to be measured. Among them, the camera unit can be a camera system installed on the drone itself (for example, a camera installed on the drone and the parameters of the camera can be set through the drone), or it can be a camera device that is detachable and firmly installed under the drone (for example, a high-pixel camera). This embodiment does not specifically limit the camera unit. After obtaining the orthophoto of the area to be measured, the orthophoto is detected by a target detection algorithm, and the crop is framed by a detection frame according to the size of the crop, and the center point of the detection frame is used as the crop point corresponding to the crop.

[0079] It should be noted that the area to be measured refers to the area where the plant spacing measurement operation is to be performed, which can be the entire area of the plot or a certain area in the plot. Figure 2As shown, the area formed by vertices A1, A2, A3, A4, A5, and A6 is defined as the first area, the area formed by vertices B1, B2, B3, and B4 is defined as the second area, and the area formed by vertices C1, C2, C3, and C4 is defined as the third area, to facilitate the specific description of different areas below. The first area is the area of the entire plot. Since the first area does not belong to a regular quadrilateral, when the area to be measured is the first area, in other words, when all crops in the area of the entire plot need to be measured, it is necessary to ensure that each crop in the plot is included in the orthophoto map, and then obtain the orthophoto map of the third area. If it is necessary to measure a certain area of the first area, such as the second area, the orthophoto map of the second area is directly obtained. Since the third area contains areas where no crops are planted or crops are planted that are different from those in the first area, it can also be understood as an area that is different from the first area. Therefore, the orthophoto map formed by the third area is prone to errors in subsequent detection and calculation. Therefore, for plots that are not regular quadrilaterals, it is preferred to select a certain area within the plot for measurement. Of course, specific adjustments can also be made based on the specific measurement scenario.

[0080] An orthophoto is a set of digital orthophotos generated by digitally differentially correcting and mosaicking aerial (or aerospace) photographs and cropping them according to a certain map range. It is an image with both map geometric accuracy and image characteristics. A target detection algorithm is an algorithm used to identify targets and their positions in an image. In this application, an orthophoto of the area to be measured is obtained by shooting, and the orthophoto is detected by a target detection algorithm to achieve accurate determination of all crop points in the area to be measured. Since the sizes of crops vary, and the orthophoto is taken from above the area to be measured, in order to better achieve accurate determination of the specific positions of the crop points and subsequently achieve accurate measurement of the crop spacing, the crop is framed by a detection frame according to its size, and the center point of the detection frame is used as the crop point.

[0081] In addition, it should be noted that since subsequent calculations are all based on the crop points formed by the orthophoto map of the area to be measured, the distance between the starting crop point and the adjacent crop points (i.e., the length of the target line segment) finally determined actually refers to the pixel distance between the starting crop point and the adjacent crop points based on the orthophoto map. Therefore, it is ultimately necessary to use the pixel distance and the preset height when the orthophoto map was collected to calculate the actual distance between the starting crop point and the adjacent crop points in the actual state.

[0082] Step S2: Select a crop point as the starting crop point, determine a search area based on the position of the starting crop point, and use the crop points within the search area as the ending crop points.

[0083] For example, any one of the crop points in the area to be measured is selected as the starting crop point, a straight line passing through the starting crop point and perpendicular to the preset crop row where the starting crop point is located is used as a dividing line, the area to be measured is divided by the dividing line, the area in the set direction of the preset crop row where the starting crop point is located is used as the search area, and the crop points in the search area are used as the ending crop points.

[0084] Specifically, combined Figure 3 As shown, the area formed by vertex D1, vertex D2, vertex D3, and vertex D4 is the area to be measured. The orthophoto image of the area to be measured is obtained and detected by the target detection algorithm. The crop is framed by the detection frame according to the crop size, and the center point of the detection frame is used as the crop point corresponding to the crop. Since all crop points in the area to be measured will be traversed later, a crop point can be selected at this time. At the same time, in order to facilitate the understanding of the plant spacing measurement method disclosed in this application, Figure 3 The crop point O1 in FIG is taken as the starting crop point for demonstration.

[0085] Determine the preset crop row where the starting crop point O1 is located. Figure 4 As shown, the preset crop row refers to the crop row in the ideal state that is pre-set by the machine when sowing crops (i.e., straight line L1), and in the ideal state, the machine sows crops in sequence along the straight line L1; however, due to the uneven terrain of the land, machine failure, etc., when crops are sown in sequence under actual conditions, there will be a deviation from the crop row in the ideal state. Therefore, in order to facilitate the subsequent determination of the straight line passing through the starting crop point and perpendicular to the preset crop row where the starting crop point is located, and in order to facilitate the subsequent determination of the angle formed by the line segment formed by the starting crop point and the ending crop point and the preset crop row where the starting crop point is located, the preset crop row where the starting crop point is located is understood as the crop row passing through the starting crop point and parallel to the crop row in the ideal state (for example, if Figure 4 The crop point E in the figure is taken as the starting crop point, and the preset crop row where the starting crop point E is located is the straight line L2).

[0086] Ginseng Figure 5 As shown in FIG, the preset crop row where the starting crop point O1 is located is determined to be straight line L4, and the straight line passing through the starting crop point O1 and perpendicular to the preset crop row where the starting crop point O1 is located is straight line L3, and the straight line L3 is used as the dividing line to divide the area to be measured by the dividing line, that is, the area to be measured composed of vertices D1, D2, D3, and D4 is divided by straight line L3 to obtain two areas, namely Figure 5 The fourth and fifth areas shown in FIG.

[0087] Ginseng Figure 3As shown, the preset crop row where the starting crop point O1 is located is determined to be straight line L4. Since the plant spacing refers to the distance between two adjacent crops in the same crop row, and the crop points O2 and O3 along two directions (i.e., along direction F1 and along direction F2) of the starting crop point O1 on straight line L4 are both adjacent crop points of the starting crop point O1, one of the two directions is selected as the set direction (which can be direction F1 or direction F2), and only the plant spacing between the starting crop point O1 and the adjacent crop points in one direction is calculated to reduce the amount of calculation of the plant spacing between the starting crop point O1 and its adjacent crop points in the same crop row. At the same time, if the set direction is determined to be direction F1 or direction F2, then when all crop points in the area to be measured are traversed subsequently, the plant spacing is calculated along direction F1 or direction F2 to prevent the repeated calculation of the distance between crop point O1 and crop point O2, which is caused by calculating the plant spacing along direction F1 when calculating crop point O1 and calculating the distance between crop point O1 and crop point O2, and calculating the distance between crop point O1 and crop point O2 along direction F2 when calculating crop point O2. This solves the problem of incomplete plant spacing measurement caused by this situation.

[0088] Combine Figure 3 and Figure 5 As shown, the set direction is set as direction F2 for illustrative purposes. With starting crop point O1 as the base point, the area along line L4 along direction F2 is defined as the search area, i.e., the fifth area, and all crop points within the search area are defined as the ending crop points. Since plant spacing refers to the distance between two crops in the same crop row, crop points at the search area boundary are eliminated to reduce the computational effort required to subsequently determine the ending crop point. Therefore, in this application, "within the search area" refers to the area within the search area and does not include the area at the search area boundary.

[0089] More specifically, Figure 6 As shown, a rectangular coordinate system is established with vertex D2 of the area to be measured as the origin. The line between vertices D2 and D3 is the X-axis, and the line between vertices D1 and D2 is the Y-axis. Crop points are marked in this established rectangular coordinate system, and the coordinates corresponding to different crop points within the rectangular coordinate system are determined. The coordinates of the starting crop point O1 are determined. If the set direction is set to direction F2, the crop point with a ordinate less than the ordinate of the starting crop point O1 is used as the ending crop point. If the set direction is set to direction F1, the crop point with a ordinate greater than the ordinate of the starting crop point O1 is used as the ending crop point.

[0090] Of course, a plane rectangular coordinate system can also be established with vertex D1, vertex D3 or vertex D4 as the origin, and the end crop point can be determined based on the vertical coordinate. The specific determination method can be inferred from the above method, and this embodiment will not be repeated here.

[0091] Step S3: Perform a screening operation on the ending crop point based on the angle formed by the line segment formed by the starting crop point and the ending crop point relative to the preset crop row where the starting crop point is located, so as to determine the adjacent crop points of the starting crop point in the set direction of the preset crop row where the starting crop point is located, and calculate the distance between the starting crop point and the adjacent crop points.

[0092] For example, Figure 7 As shown, the aforementioned step S3 performs a screening operation on the ending crop point based on the angle formed by the line segment formed by the starting crop point and the ending crop point relative to the preset crop row where the starting crop point is located, specifically including the following steps S31 to S32.

[0093] Step S31 : connecting the starting crop point and the ending crop point to form a plurality of line segments, and determining the angles formed by the line segments and the preset crop row where the starting crop point is located.

[0094] Specifically, Figure 8 The crop points O3, O4, O5, O6, O7, O8, O9, O10, O11, and O12 shown in the figure are crop points within the search area determined based on the position of the starting crop point O1. The crop points within the search area are designated as the ending crop points, namely, ending crop point O3, ending crop point O4, ending crop point O5, ..., ending crop point O11, and ending crop point O12. Starting crop point O1 is connected to the ending crop points, namely, starting crop point O1 is connected to ending crop point O3, starting crop point O1 is connected to ending crop point O4, starting crop point O1 is connected to ending crop point O5, and so on, to form several line segments, namely, line segment O1O3, line segment O1O4, line segment O1O5, and so on. Simultaneously, the angle formed by each line segment and the predetermined crop row (i.e., line L4) where starting crop point O1 is located is calculated.

[0095] Step S32: perform validity determination on the line segments to eliminate line segments with angles greater than a preset angle, obtain valid line segments and their number, and select a valid line segment as a target line segment based on the number of valid line segments and the size of the angle.

[0096] Exemplarily, the preset angle includes a first preset angle and / or a second preset angle, wherein the first preset angle is a fixed value and the second preset angle is a fixed value. a is the preset maximum distance between plants, and b is the length of the line segment.

[0097] Specifically, the angles formed by the line segments formed by the starting crop point O1 and the ending crop point relative to the preset crop row (i.e., line L4) where the starting crop point O1 is located are determined, and the line segments with angles greater than a first preset angle are eliminated. For example, if the first preset angle is set to 60°, the line segments with angles greater than 60° are eliminated. Figure 8 As shown, if the angles formed by line segments O1O7 and O1O5 with straight line L4 are greater than 60°, then line segments O1O7 and O1O5 are removed, and line segments O1O3, O1O4, O1O6, O1O8, O1O9, O1O10, O1O11, and O1O12 are retained. Then, among the eight retained line segments, the line segments with angles greater than the second preset angle are removed. Assuming that the preset maximum plant spacing a is 0.6 meters, line segment O1O6 is used as an example. The length of line segment O1O6 is 0.2 meters, then If the angle formed by the line segment O1O6 and the straight line L4 is greater than 32°, the line segment O1O6 is eliminated; if the angle is less than or equal to 32°, the line segment O1O6 is retained and defined as a valid line segment, and so on.

[0098] It should be noted that by setting a fixed value and defining it as the first preset angle, line segments with angles greater than the first preset angle are eliminated, thereby eliminating crop points that clearly do not belong to the same crop row as the starting crop point O1, further improving calculation efficiency, avoiding excessive interference from crop points in other crop rows, and thus improving calculation accuracy. By defining the calculation formula for the second preset angle: A preset maximum plant spacing is determined, and a second preset angle is calculated based on the line segment length. According to the calculation formula for the second preset angle, the longer the line segment length, the smaller the second preset angle, thereby further avoiding interference from crop points in other crop rows. The preset angles include a first preset angle and / or a second preset angle. Line segments can be eliminated using only the first preset angle, or only the second preset angle. Alternatively, as described above, line segments can be eliminated first using the first preset angle and then using the second preset angle to further improve calculation efficiency, avoid interference from crop points in other crop rows, and thereby improve calculation accuracy. This selection can be made based on the specific scenario and is not limited in this embodiment. The line segments ultimately retained are defined as valid line segments, and the number of valid line segments is determined.

[0099] Ginseng Figure 9 As shown, the aforementioned step S32 of selecting a valid line segment as a target line segment based on the number of valid line segments and the size of the included angle includes the following steps S321 to S323.

[0100] Step S321, determine whether the number of valid line segments is less than a preset number; if so, execute step S322; if not, execute step S323.

[0101] Step S322: Select the valid line segment with the smallest angle with the preset crop row where the starting crop point is located as the target line segment.

[0102] Step S323: Select two valid line segments with shorter lengths from the valid line segments, and determine the valid line segment based on whether the length of the shortest valid line segment among the two valid line segments is less than a multiple of the length of the other valid line segment.

[0103] Ginseng Figure 10 As shown, the aforementioned step S323 specifically includes the following steps S331 to S326.

[0104] Step S331, preset a parameter k, and determine whether the shortest valid line segment length is less than another valid line segment length that is k times the parameter, 0<k<1; if so, execute step S332; if not, execute step S333.

[0105] Step S332: Select the shortest valid line segment as the target line segment.

[0106] Step S333: Select the valid line segment with the smallest angle with the preset crop row where the starting crop point is located from among the valid line segments as the target line segment.

[0107] Among them, the parameters c is the average value of the preset plant spacing, d is the average value of the preset row spacing, and e is the adaptation coefficient.

[0108] Ginseng Figure 11 As shown, after selecting a valid line segment as a target line segment based on the number of valid line segments and the size of the included angle, the following steps S341 to S343 are also included.

[0109] Step S341, determine whether the length of the target line segment is greater than a preset length; if so, execute step S342; if not, execute step S343.

[0110] Step S342: Delete the target line segment and determine that no adjacent crop points of the starting crop point in the set direction of the preset crop row exist.

[0111] Step S343: Determine the ending crop point corresponding to the target line segment as an adjacent crop point of the starting crop point in a set direction of the preset crop row.

[0112] The preset length is the product of the empirical coefficient and the average length of the valid line segments.

[0113] Specifically, assuming the preset number is 4, Figure 12As shown in FIG, if the number of valid line segments is less than the preset number, that is, the number of valid line segments is 3<4, then the valid line segment with the smallest angle with the preset crop row (i.e., straight line L4) where the starting crop point O1 is located is selected as the target line segment, that is, the valid line segment O1O3 is selected as the target line segment; Figure 13 As shown, if the number of valid line segments is not less than the preset number (i.e., the number of valid line segments ≥ the preset number), and the number of valid line segments is 4 ≥ 4, then the two valid line segments with shorter lengths are selected, and the valid line segments are determined based on whether the length of the shortest valid line segment among the two valid line segments is less than a multiple of the length of the other valid line segment.

[0114] Assume that the average value of the preset plant spacing c is 0.2m, and the average value of the preset row spacing d is 0.5m. Among them, the average value of the preset plant spacing c and the average value of the preset row spacing d refer to the average value of the plant spacing and the average value of the row spacing under the ideal state set by the machine when planting crops. Due to the different crops, the plant spacing and row spacing between the father rows, between the mother rows, and between the father row and the mother row are different (for example, corn planting), so the average value of the plant spacing and the average value of the row spacing are taken for calculation, and the adaptation coefficient e is calculated accordingly to ensure a reasonable estimate of the actual crop planting conditions in the measured area. The adaptation coefficient obtained according to the average value of the plant spacing and the average value of the row spacing in the measured area is more suitable for the measured area, so as to ensure adaptability and rationality, thereby improving generalization ability. Adaptation coefficient parameter Ginseng Figure 13 As shown, two valid line segments with shorter lengths are selected from the valid line segments, namely, the valid line segment O1O3 and the valid line segment O1O4, wherein the length of the valid line segment O1O3 is greater than the length of the valid line segment O1O4, and then it is determined whether the length of the valid line segment O1O4 is less than 0.77 times the length of the valid line segment O1O3. If the length of the effective line segment O1O4 is less than 0.77*the length of the effective line segment O1O3, the shortest effective line segment is selected as the target line segment, that is, the effective line segment O1O4 is selected as the target line segment; if the length of the effective line segment O1O4 is greater than or equal to 0.77*the length of the effective line segment O1O3, the effective line segment with the smallest angle with the preset crop row (that is, the straight line L4) where the starting crop point O1 is located is selected as the target line segment, that is, the line segment with the smallest angle with the straight line L4 among the effective line segments O1O2, the effective line segment O1O3, the effective line segment O1O4, and the effective line segment O1O5 is selected as the target line segment, that is, the effective line segment O1O3 is selected as the target line segment.

[0115] It should be noted that under normal sowing conditions, three valid line segments are generally determined: the starting crop point and the adjacent crop point in the set direction of the preset crop row, and the starting crop point and the two closest crop points in the two adjacent crop rows of the preset crop row. However, when the machine sows unevenly, missed or oversown crops may occur. If there are multiple crops sown between the starting crop point and its adjacent crop points in the same crop row, and the angle between the multiple crops and the preset crop row where the starting crop point is located is large, the multiple crops can easily be eliminated, resulting in missed detection.

[0116] Specifically, Figure 14 As shown in , when three points are selected, if there is multicast, the length of the effective line segment O1O4 ≥ k * the length of the effective line segment O1O3, then the effective line segment with the smallest angle with the preset crop row (i.e., straight line L4) where the starting crop point O1 is located is selected as the target line segment, that is, the effective line segment O1O3 is selected as the target line segment; and by Figure 14 It can be seen that in actual conditions, the valid line segment O1O4 should be selected as the target line segment, which causes the problems of missed detection and false detection. Figure 15 As shown, when three points are selected, if there is a missed broadcast, the length of the effective line segment O1O2 is less than k* the length of the effective line segment O1O4, then the shortest effective line segment is selected as the target line segment, that is, the effective line segment O1O2 is selected as the target line segment; and by Figure 15 It can be seen that in actual conditions, line segment O1O5 should be selected as the target line segment, but line segment O1O5 does not belong to the valid line segment. Therefore, no matter which valid line segment is selected, it will cause the problem of missed detection and false detection. It can be seen that judging the target line segment by detecting three points is easy to cause the problem of missed detection and false detection, and then cause the problem of low accuracy of plant spacing detection. Therefore, in this application, the preset number is set to 4 for exemplary explanation. When the number of valid line segments is ≥4, the method shown in the above step S323 is used to determine the valid line segment, and the adjacent crop points on the same crop row of the starting crop point are accurately identified, so as to solve the problem of inaccurate plant spacing measurement results caused by the inability to accurately identify crops on the same crop row in the prior art. At the same time, it also solves the problem of missed detection and false detection when selecting three points, and further improves the accuracy of subsequent plant spacing measurements. Of course, the preset number can also be other values, such as 5, 6, etc., and is preferably 4.

[0117] Ginseng Figure 16 As shown in the figure, when four points are selected, the two shorter valid line segments are selected, namely, valid line segments O1O2 and valid line segments O1O4. A circle is constructed with the starting crop point O1 as the center and k*the length of the valid line segment O1O4 as the radius. If the length of the valid line segment O1O2 is less than k*the length of the valid line segment O1O4, then the ending crop point O2 is inside the circle; and by Figure 16 It can be seen that even if the angle between the effective line segment O1O4 and the preset crop row where the starting crop point O1 is located is smaller than the angle between the effective line segment O1O2 and the preset crop row where the starting crop point O1 is located, the effective line segment O1O2 is still selected as the target line segment. Figure 17 As shown, if the length of valid line segment O1O2 ≥ k* the length of valid line segment O1O4, that is, the ending crop point O2 is located outside the circle or at the circle's boundary, there is a possibility that the ending crop point O2 is a crop point in the crop row adjacent to the starting crop point O1. Therefore, the valid line segment with the smallest angle among the four valid line segments (i.e., valid line segment O1O4) is selected as the target line segment. Therefore, by selecting the two shorter valid line segments and determining whether the length of the shortest of the two selected valid line segments is less than the length of the other valid line segment times the parameter k, a limited range is formed. If the ending crop point corresponding to the shortest valid line segment length is within the limited range, the ending crop point is determined to be the adjacent crop point in the crop row of the starting crop point in the set direction. If the ending crop point is outside the limited range, the ending crop point is determined to be the crop point in the crop row adjacent to the crop row of the starting crop point. This addresses the problem of crop point offset during machine sowing and avoids interference from crop points in adjacent crop rows, ultimately ensuring the accuracy of plant spacing measurement.

[0118] After determining the target line segment, a determination is made as to whether its length is greater than a preset length. The preset length is the product of an empirical coefficient and the average length of valid line segments. The empirical coefficient is a user-derived value based on experience. The target line segment is then reassessed based on the empirical coefficient to further ensure the accuracy of plant spacing measurement. The empirical coefficient is greater than 1 and less than 5, preferably 3. The determination is made as to whether the length of the target line segment is greater than the preset length. If so, the target line segment is deleted, and it is determined that no adjacent crop points exist in the preset direction of the starting crop point within the preset crop row. If not, the ending crop point corresponding to the target line segment is determined as the adjacent crop point in the preset direction of the starting crop point within the preset crop row. This prevents row breakage during machine planting and avoids selecting an ending crop point that is too far away.

[0119] After determining the adjacent crop points, the distance between the starting crop point and the adjacent crop points, that is, the length of the target line segment, is calculated, and the length of the target line segment is used as the plant spacing between the starting crop point and the adjacent crop points in the set direction of the preset crop row where it is located.

[0120] Since the plant spacing measurements above are based on crop points generated by orthophotos, the calculated plant spacing between the starting crop point and adjacent crop points is actually the pixel distance between the starting crop point and adjacent crop points based on the orthophotos. Therefore, the actual distance between the starting crop point and adjacent crop points in real-world conditions is calculated by combining this calculated pixel distance with the preset height when the orthophotos were collected.

[0121] Step S4: Repeat steps S2 to S3 to traverse the crop points in the area to be measured, so as to perform plant spacing measurement operations on the crop points in the area to be measured.

[0122] Through steps S2 to S3 above, the crop points in the area to be measured are traversed until all crop points in the area to be measured are selected as the starting crop point. The plant spacing between the starting crop point and the adjacent crop points in the set direction of the preset crop row is calculated. Based on the preset height when the orthophoto image was collected, this plant spacing is converted to the actual distance under actual conditions to perform the plant spacing measurement operation on the crop points in the area to be measured. After performing the plant spacing measurement operation, the obtained plant spacings are used to calculate the average and variance of the plant spacing of the crop points in the area to be measured, so that the user can evaluate the area to be measured.

[0123] Furthermore, based on the specific example of the plant spacing measurement method described above, this embodiment also discloses a plant spacing measurement system 100. Figure 18 As shown, the plant spacing measurement system 100 includes: a detection unit 101 , a measurement unit 102 and a calculation unit 103 .

[0124] The detection unit 101 is used to obtain crop points in the area to be measured; the measurement unit 102 is used to select a crop point as the starting crop point, determine the search area according to the position of the starting crop point, and use the crop points in the search area as the ending crop points, and perform a screening operation on the ending crop point based on the angle formed by the line segment formed by the starting crop point and the ending crop point relative to the preset crop row where the starting crop point is located, so as to determine the adjacent crop points of the starting crop point in the set direction of the preset crop row, calculate the distance between the starting crop point and the adjacent crop points, traverse the crop points in the area to be measured, and perform a plant spacing measurement operation on the crop points in the area to be measured; the calculation unit 103 is used to calculate the seedling emergence rate of the area to be measured based on the plant spacing of the crop points in the area to be measured.

[0125] It should be noted that the logic contained in step S1 of the aforementioned plant spacing measurement method is implemented by detection unit 101 in plant spacing measurement system 100, and the logic contained in steps S2 through S4 is implemented by measurement unit 102 in plant spacing measurement system 100. Therefore, the specific implementation of detection unit 101 and measurement unit 102 can be found in the previous description and will not be repeated here.

[0126] The calculation formula for calculating the emergence rate of the area to be measured in the calculation unit 103 is as follows:

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136] Where x is the number of parent rows in the area to be measured, and y is the number of parent rows in the area to be measured.

[0137] Specifically, the actual seedling density in formula (1) refers to the seedling density of crops in the area to be measured under actual conditions, and the preset seedling density refers to the seedling density of crops in the area to be measured under ideal conditions. The number of crops in the area to be measured in formula (2) refers to the number of crops in the area to be measured under actual conditions. The sire row spacing in formula (3) refers to the row spacing between sire rows in the area to be measured under ideal conditions, the maternal row spacing refers to the row spacing between maternal rows in the area to be measured under ideal conditions, and the parent row spacing refers to the row spacing between sire rows and maternal rows in the area to be measured under ideal conditions. The sire row intra-density in formula (4) refers to the intra-row density of the sire row in the area to be measured under ideal conditions. The maternal row intra-density in formula (5) refers to the intra-row density of the maternal row in the area to be measured under ideal conditions. As for the specific meanings of the same wording in the above formulas, please refer to other formulas and will not be repeated here.

[0138] If the crops planted in the area to be measured are all male plants, the above formulas (1), (2), (4) and (7) are used to calculate the emergence rate of the area to be measured; if the crops planted in the area to be measured are all female plants, the above formulas (1), (2), (5) and (9) are used to calculate the emergence rate of the area to be measured; if the crops planted in the area to be measured include male plants and female plants, the above formulas (1), (2), (3), (6), (7), (8) and (9) are used to calculate the emergence rate of the area to be measured.

[0139] The intra-row density of the male parent and the intra-row density of the female parent can be decimals. For example, if the length of the crop row is ten meters and the number of seedlings sown in the crop row is 25, the intra-row density is 2.5 plants / meter.

[0140] In addition, the germination rate in the aforementioned formula (6) refers to the percentage of the number of test seeds that germinated to the total number of test seeds. For example, if 95 out of 100 test seeds germinated, the germination rate is 95%. Germination rate is one of the important indicators for measuring planting quality and is often used to calculate seed usage in agricultural production. Germination rate varies depending on the variety, the physiological state of the seed, and the seed coating. In actual calculations, the germination rate of the variety test is generally used, for example, 95%. The additional sowing rate is obtained based on seed vigor. Seed vigor is the sum of seed germination and emergence rate, seedling growth potential, plant stress resistance, and production potential. It is an important indicator of seed quality. At the same time, the effect of seed activity on germination rate is considered. When seed vigor is less than 80, an additional 5% sowing is required to compensate for the low germination rate caused by low seed vigor. Otherwise, no additional sowing rate is required (i.e., the additional sowing rate is set to 0 and substituted into formula (6)).

[0141] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0142] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0143] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A plant spacing measurement method, characterized in that: include: S1. Obtain an orthophoto of the area to be measured, frame the crop according to its size, and use the center point of the frame as the crop point corresponding to the crop; S2. Select a crop point as the starting crop point, determine a search area based on the position of the starting crop point, and use the crop points within the search area as the ending crop points; S3. Performing a screening operation on the ending crop point based on an angle formed by a line segment formed by the starting crop point and the ending crop point relative to the preset crop row where the starting crop point is located, to determine adjacent crop points of the starting crop point in a set direction of the preset crop row where the starting crop point is located, and calculating the distance between the starting crop point and the adjacent crop points; S4, repeating steps S2 to S3, traversing the crop points in the area to be measured, and performing a plant spacing measurement operation on the crop points in the area to be measured; The preset crop rows refer to crop rows in an ideal state that is preset when sowing crops.

2. The plant spacing measurement method according to claim 1, characterized in that: The step of framing the crop according to the crop size and using the center point of the frame as the crop point corresponding to the crop includes: The orthophoto image is detected using the target detection algorithm, and the crop is framed by a detection frame according to the crop size, with the center point of the detection frame as the crop point corresponding to the crop.

3. The plant spacing measurement method according to claim 1, characterized in that: Determining the search area according to the position of the starting crop point includes: A straight line passing through the starting crop point and perpendicular to the preset crop row where the starting crop point is located is used as a dividing line, the area to be measured is divided by the dividing line, and the area in the set direction of the preset crop row where the starting crop point is located is used as the search area.

4. The plant spacing measurement method according to claim 1, characterized in that: The performing a screening operation on the ending crop point based on an angle formed by a line segment formed by the starting crop point and the ending crop point relative to a preset crop row where the starting crop point is located includes: Connecting the end crop points respectively from the starting crop points to form a plurality of line segments, and determining angles formed between the line segments and the preset crop rows where the starting crop points are located; The line segments are judged to be effective, so as to eliminate the line segments with angles greater than the preset angle, and take the line segments with angles less than or equal to the preset angle as effective line segments, obtain the effective line segments and their number, and select a effective line segment as the target line segment based on the number of effective line segments and the size of the angle.

5. The plant spacing measurement method according to claim 4, characterized in that: The preset angle includes a first preset angle and / or a second preset angle; The first preset angle is a fixed value, and the second preset angle is a is the preset maximum distance between plants, and b is the length of the line segment.

6. The plant spacing measurement method according to claim 5, characterized in that: The selecting a valid line segment as a target line segment based on the number of valid line segments and the size of the included angle includes: Determine whether the number of valid line segments is less than a preset number; If so, the valid line segment with the smallest angle with the preset crop row where the starting crop point is located is selected as the target line segment; If not, two valid line segments with shorter lengths are selected from the valid line segments, and the target line segment is determined based on whether the length of the shortest valid line segment among the two valid line segments is less than a multiple of the length of the other valid line segment.

7. The plant spacing measurement method according to claim 6, characterized in that: The determining of the target line segment based on whether the length of the shortest valid line segment of the two valid line segments is less than a multiple of the length of the other valid line segment includes: Preset a parameter k and determine whether the shortest valid line segment length is less than another valid line segment length that is k times the parameter, 0<k<1; If so, the shortest valid segment is selected as the target segment; If not, the valid line segment with the smallest angle with the preset crop row where the starting crop point is located is selected as the target line segment; Among them, the parameters c is the average value of the preset plant spacing, d is the average value of the preset row spacing, and e is the adaptation coefficient.

8. The plant spacing measurement method according to claim 4, characterized in that: After selecting a valid line segment as a target line segment based on the number of valid line segments and the size of the included angle, the method further includes: Determine whether the length of the target line segment is greater than the preset length; If yes, the target line segment is deleted, and it is determined that no adjacent crop points of the starting crop point in the set direction of the preset crop row exist; If not, the ending crop point corresponding to the target line segment is determined as the adjacent crop point of the starting crop point in the set direction of the preset crop row; The preset length is the product of the empirical coefficient and the average length of the valid line segments.

9. The plant spacing measurement method according to any one of claims 1 to 8, characterized in that: After performing the plant spacing measurement operation on the crop points in the area to be measured, the method includes: Calculate the mean and variance of the plant spacing of the crop points in the area to be measured.

10. A plant spacing measurement system, characterized in that: include: The detection unit is used to obtain an orthophoto of the area to be measured, frame the crop according to its size, and use the center point of the frame as the crop point corresponding to the crop; a measurement unit configured to select a crop point as a starting crop point, determine a search area based on a position of the starting crop point, and use crop points within the search area as ending crop points; perform a screening operation on the ending crop point based on an angle formed by a line segment formed by the starting crop point and the ending crop point relative to a preset crop row in which the starting crop point is located, so as to determine adjacent crop points of the starting crop point in a set direction of the preset crop row in which the starting crop point is located, calculate a distance between the starting crop point and the adjacent crop points, traverse crop points in the area to be measured, and perform a plant spacing measurement operation on the crop points in the area to be measured; The preset crop rows refer to crop rows in an ideal state that is preset when sowing crops.

11. The plant spacing measurement system according to claim 10, characterized in that: Also includes: The calculation unit is used to calculate the emergence rate of the area to be measured based on the spacing of the crop points in the area to be measured. The specific calculation formula of the emergence rate is as follows: Where x is the number of parent rows in the area to be measured, and y is the number of parent rows in the area to be measured.

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