Device and method for measuring height and crown breadth of tobacco plant

Abstract

The invention belongs to the technical field of tobacco field tobacco plant measuring equipment, and particularly provides an automatic tobacco plant height and crown breadth measuring device and method integrating a telescopic rod, a lead screw, a pressing plate and three laser range finders. The device body is the telescopic rod with the adjustable height, the top of the telescopic rod is horizontally connected with the lead screw, the pressing plate is arranged on the periphery of a sleeve arranged outside the lead screw in a sleeving mode, and the three laser range finders are arranged on the pressing plate; through cooperation of the pressing plate, the measuring plate and the sliding block and arrangement of the first laser range finder, the second laser range finder and the third laser range finder in three directions, the plant top and the canopy edge can be automatically aligned without manual vision, and the controller accurately controls driving and lead screw movement according to real-time signals of all the laser range finders. And finally measuring to obtain the plant height and crown breadth of the tobacco plant. According to the device, the pressing plate is automatically aligned with the tobacco plants, personal errors are reduced, shielding and reflection interference of adjacent plants are effectively eliminated through multi-direction cooperative distance measurement, and the measurement precision and efficiency are greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of tobacco plant measuring equipment in tobacco fields, and particularly relates to a device and method for measuring tobacco plant height and crown width. Background Art

[0002] When studying tobacco growth, measuring plant height and crown width is often necessary. Traditionally, these measurements are performed manually using a soft or steel tape measure. This method is not only time-consuming and labor-intensive, but also results in large measurement errors and low accuracy due to operator visual judgment and variations in measurement angle. Furthermore, some tobacco plants can exceed 1.7 meters in height at maturity, making height measurement highly dependent on the height of the operator, significantly increasing the difficulty of the operation.

[0003] Existing plant height and crown width measurement devices based on laser ranging usually keep a certain distance between the measuring device and the target plant, aim at the edge of the plant crown in an oblique manner by adjusting the pitch angle and horizontal deflection angle of the laser rangefinder, and use the principle of triangulation to calculate the plant height and crown width. However, this type of method has many shortcomings in practical applications: first, manual visual alignment is required to determine whether the laser beam accurately coincides with the edge of the crown; if the observation angle or lighting conditions are poor, measurement deviations are likely to occur, affecting the accuracy of the results; second, due to the small row and plant spacing of tobacco plants, the leaves of adjacent non-target tobacco plants may block or reflect the laser beam, causing the laser path to deviate or multiple reflections, thereby affecting the accuracy of the distance measurement.

[0004] In order to solve at least one of the above problems, the present application is proposed. Summary of the Invention

[0005] In view of the problems that existing plant height and crown width measuring devices require manual aiming, or are easily affected by environmental interference and layout location restrictions, the purpose of the present invention is to provide a device and method for measuring tobacco plant height and crown width, which can achieve automatic alignment, reduce human errors, and effectively eliminate interference from adjacent plants, significantly improving measurement accuracy and efficiency.

[0006] A first aspect of the present invention provides a device for measuring the height and crown width of tobacco plants, the device comprising:

[0007] A vertically arranged telescopic rod 1;

[0008] A screw rod detachably connected to one side of the top of the telescopic rod 1 and arranged in the horizontal direction, the screw rod comprising a screw rod 21 and a nut 22;

[0009] A pressing plate 3 is provided on the outer periphery of the screw 21 for pressing against the top of the tobacco plant crown;

[0010] A first laser rangefinder 4 is installed below the nut 22, and the first laser rangefinder 4 is arranged vertically downward;

[0011] A distance measuring assembly is mounted on the telescopic rod 1 on the side facing the first laser rangefinder 4. The distance measuring assembly includes a driving mechanism 51 and a second laser rangefinder 52 and a third laser rangefinder 53 provided on the telescopic end of the driving mechanism 51. The second laser rangefinder 52 is arranged in the horizontal direction for measuring the crown width, and the third laser rangefinder 53 is arranged in the vertical direction for measuring the plant height.

[0012] and a controller, the controller being in communication with the laser rangefinder, the pushing mechanism, and the lead screw, and being configured to control the movement of the pushing mechanism 51 and the lead screw according to a measurement signal from the laser rangefinder;

[0013] The measuring ends of the first laser rangefinder 4 and the third laser rangefinder 53 are flush with the bottom end of the pressing plate 3 to ensure that the measurement references are consistent.

[0014] The pushing mechanism 51 can be a linear driving device 13 such as an electric push rod.

[0015] Preferably, the screw rod is detachably connected to one side of the top end of the telescopic rod 1 through a mounting sleeve 6 .

[0016] Preferably, a driving device 13 is further provided on the top of the telescopic rod 1;

[0017] One end of the screw rod 21 is movably connected to the driving device 13 through a connecting piece, and the other end extends to the far side of the pressing plate 3;

[0018] After the screw rod 21 extends from the driving device 13, a sleeve 7 is coaxially sleeved on the outer peripheral surface of the end connected to the driving device 13; one end of the sleeve 7 is fixedly connected to the outer wall of the telescopic rod 1 or the outer shell of the driving device 13, and the other end extends horizontally to the far side of the pressing plate 3;

[0019] The top end of the pressure plate 3 is fixedly connected to the outer wall of the sleeve 7 through a connecting rod 31. A horizontal avoidance hole is provided on the connecting rod 31. The axis of the avoidance hole coincides with the laser emission path of the second laser rangefinder 52 to avoid blocking the measuring light path of the second laser rangefinder 52.

[0020] Preferably, the distance measuring assembly also includes a slider 54 arranged between the connecting end of the sleeve 7 and the pressure plate 3, the top end of the slider 54 is slidably connected to the outer peripheral wall of the sleeve 7, and the side wall is connected to the telescopic end of the pushing mechanism 51, and the second laser rangefinder 52 and the third laser rangefinder 53 are respectively installed on one side and the bottom end of the slider 54 facing the pressure plate 3.

[0021] Among them, the specific dimensions and installation positions of components such as the telescopic rod 1, screw 21, sleeve 7, and pressure plate 3 can be appropriately adjusted according to the height and crown width range of the actual measurement object. It is only necessary to ensure that the device can accurately measure the height and crown width of the tobacco plant.

[0022] Preferably, the bottom end of the telescopic rod 1 is further provided with a spike portion 11, the top end of which is hingedly connected to a plurality of legs 111 along the circumferential direction. Each leg 111 can be folded or unfolded relative to the spike portion 11 to enhance the support stability of the device at the base of the plant. The spike portion 11 and the legs 111 enhance stability in soft soil in the field.

[0023] Preferably, a marking rod 8 is connected to the outer wall of the telescopic rod 1 above the spike portion 11. The marking rod 8 is slidably connected to the outer wall of the telescopic rod 1 through a positioning ring 81 and can be positioned and locked at any position in the middle of the telescopic rod 1; after locking, the marking rod 8 is positioned directly below the measuring end of the third laser rangefinder 7. The marking rod (8) can slide and lock along the telescopic rod to adapt to different tobacco plant root heights.

[0024] Preferably, a plurality of pressure sensors or flexible tactile sensors are provided on the side of the pressing plate 3 facing the tobacco plant, for detecting the contact state and posture changes between the pressing plate and the base of the plant in real time to ensure measurement accuracy.

[0025] Preferably, the first laser rangefinder 4 is mounted below the measuring plate 41 and connected to the nut 22 via the measuring plate 41. The outer peripheral wall of the free end of the sleeve 7 is connected to one end of a limiting rod 9, the other end of which passes through the measuring plate 41 and is used to limit the sliding travel of the measuring plate 41 along the sleeve 7. Due to the presence of the limiting rod 9, the starting position of the measuring plate 41 and the nut 22 is preset on the opposite side of the pressure plate 3. That is, the pressure plate 3 is located between the measuring plate 41, on which the first laser rangefinder 4 is mounted, and the slider 54, on which the second and third laser rangefinders 52 and 53 are mounted.

[0026] Preferably, the telescopic rod 1 is a manual telescopic rod or an electric telescopic rod; the telescopic rod is also provided with a level bubble 12. The level bubble 12 ensures the verticality of the device and avoids measurement errors caused by tilt.

[0027] The level bubble 12 consists of a slightly curved, sealed glass tube partially filled with low-viscosity alcohol (such as ethanol) or mineral oil to allow for a tiny bubble. The outer wall of the glass tube is engraved with concentric circles or several parallel scale lines, and its inner diameter remains constant at the viewing window to ensure consistent readings. Because the glass tube curves slightly from the inside out, the bubble naturally floats to the highest point of the tube when in a vertical position and aligns with the concentric scale, indicating that the telescopic rod is in a completely vertical position. If the telescopic rod tilts, the liquid in the tube flows in the direction of the tilt, and the bubble deviates from the center position by a distance proportional to the tilt angle. The user can determine the direction and magnitude of the tilt by observing the bubble's offset relative to the scale and adjust the telescopic rod accordingly until the bubble returns to the center of the scale, thus restoring verticality.

[0028] When the telescopic rod 1 is a manual telescopic rod, it consists of a sleeve rod and an inner rod, wherein the inner rod can slide inside the sleeve rod; at least one longitudinal guide groove is provided on the outer circumference of the sleeve rod, and the inner rod and the sleeve rod are locked by a locking screw, which can move along the guide groove and be screwed into the outer circumference of the inner rod to achieve relative fixation of the inner rod and the sleeve rod at any position of the sleeve rod, thereby ensuring that the telescopic rod is locked at any desired length and improving the positioning stability of the structure;

[0029] When the telescopic rod 1 is an electric push rod telescopic rod, its fixed end is fixed to the upper end of the newly added base plate 101; the lower end of the base plate 101 is connected to an extension rod 10, which serves as the bottom bearing member of the electric telescopic rod. The spike 11 at the bottom of the telescopic rod 1, the legs 111 provided at the top of the spike 11, the marking rod 8 and the positioning ring 81 and other components are all fixed to the extension rod 10. Therefore, when the electric push rod telescopic rod 1 is telescoped and lifted as a whole, only the movable end of the telescopic rod moves up and down relative to the extension rod 10; the extension rod 10 and the spike 11, the legs 111, the marking rod 8, the positioning ring 81 and other components installed thereon are kept relatively stationary by virtue of the spike being inserted into the ground, thereby effectively separating the functions of the lifting and lowering adjustment of the telescopic rod and the stable support and positioning of the base of the plant.

[0030] The second aspect of the present invention provides a method for measuring tobacco plant height and crown width using the device of the first aspect, comprising the following steps:

[0031] Step (1): Place the device near the target tobacco plant, insert the spike portion 11 vertically into the soil to ensure it is firm, unfold each leg 111 so that its foot surface is close to the soil surface to further stabilize the device; then adjust the telescopic rod 1 to a fully vertical state;

[0032] Step (2): Move along the telescopic rod 1 and lock the positioning ring 81 so that the marking rod 8 is located directly below the detection end of the third laser rangefinder 7 and flush with the root of the tobacco plant;

[0033] Step (3): Control the telescopic rod 1 to shorten, so that the pressing plate 3 stops after contacting the top of the tobacco plant from top to bottom, and start the third laser rangefinder 53 to measure the distance H1 between the bottom end of the pressing plate 3 and the marking rod 8, where H1 is the height of the tobacco plant;

[0034] Step (4): Control the push mechanism 51 to extend, driving the second laser rangefinder 52 and the third laser rangefinder 53 to approach the tobacco plant; at the same time, drive the screw rod so that the nut 22 drives the first laser rangefinder 4 to synchronously approach the tobacco plant;

[0035] Step (5): The controller monitors the following data in real time:

[0036] The distance H2 from the nut 22 to the ground measured by the first laser rangefinder 4;

[0037] The real-time distance H1′ between the pressing plate 3 and the marking rod 8 measured by the third laser rangefinder 53;

[0038] The corresponding institution shall be stopped when the following conditions are met:

[0039] If H2≤H1–a, stop the screw;

[0040] If H1'≤H1–a, the pushing mechanism 51 is stopped;

[0041] Where a is the preset threshold;

[0042] Step (6): After the screw and the pushing mechanism 51 stop, the second laser rangefinder 52 measures the horizontal distance L' from the side wall of the measuring plate 41, and then calculates the crown width L of the target tobacco plant.

[0043] Preferably, the method for calculating the crown width L of the target tobacco plant is:

[0044] L=L′+b+c

[0045] in:

[0046] L′: original crown amplitude obtained by measuring the horizontal distance from the measuring end of the second laser rangefinder 52 to the side wall of the measuring plate 41;

[0047] b: Compensate for the horizontal offset between the installation point of the first laser rangefinder 4 and the side wall of the measuring plate 41 to ensure a uniform starting point for ranging;

[0048] c: Compensate for the horizontal offset between the installation position of the third laser rangefinder 53 and the side wall of the measurement plate 41 to eliminate the height measurement reference difference.

[0049] Parameters b and c can be determined once through calibration experiments based on the fixed installation distances of the first and third laser rangefinders on the measurement plate 41 (e.g., the clearance between the axis center and the sidewall). These constant values remain constant throughout all subsequent measurements. This ensures that L' truly reflects the actual crown width of the target tobacco plant, unaffected by systematic errors caused by the installation positions of the rangefinders.

[0050] The present invention uses a second laser rangefinder 52 to measure the distance from the measuring end of the second laser rangefinder 52 to the side wall of the movable plate 12 in the horizontal direction, thereby obtaining the tobacco plant crown width L. Specifically, in step (5), after the pushing mechanism 51 and the screw rod are stopped, the movable plate 12 has been pushed to a position tangent to the outer edge of the tobacco plant crown; at the same time, the second laser rangefinder 52 fixed on the slider 54 also moves synchronously and is at a position tangent to the outer edge on the other side of the tobacco plant crown; the second laser rangefinder 52 emits a horizontal laser beam to the side wall of the measuring plate 41, and accurately calculates the horizontal distance L between the laser head and the side wall by detecting the flight time or phase difference of the echo; to ensure measurement accuracy, the measuring end of the second laser rangefinder 52 can be further set on the central axis of the measuring end of the third laser rangefinder 7 to ensure that the measurement reference lines of all rangefinders coincide, thereby reducing system errors.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] 1. The present device utilizes a pressure plate, a measuring plate, and a slider, along with the placement of first, second, and third laser rangefinders in three directions, to automatically align plant tops with canopy edges without visual inspection. Combined with feedback from the controller on the drive mechanism, consistent pressure plate-plant contact and laser emission paths are ensured during each measurement, minimizing errors caused by visual judgment or operating angle deviations.

[0053] 2. A manual or electric telescopic pole, combined with spikes and foldable legs, provides quick fixation and stable support. A marker rod and locating ring ensure the repeatable and lockable reference position of the third laser rangefinder. The entire device requires no complex setup; simply insert it into the ground, deploy the legs, and lock the marker to complete the measurement of the height and crown width of a single tobacco plant.

[0054] 3. The present invention combines automatic telescopic movement with laser ranging, eliminating the need for manual repeated measurement and visual judgment. One worker can quickly complete the measurement of multiple plants in a large tobacco field. Real-time data collection is linked to the controller, and docking with a host computer or mobile terminal is possible, further simplifying the data collation and analysis process. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is a schematic diagram of the overall structure of Example 1;

[0056] Figure 2 This is a schematic diagram of the overall structure of Example 2.

[0057] Figure numerals: 1, telescopic rod; 11, spike portion; 111, support leg; 12, level bubble; 13, driving device; 21, screw; 22, nut; 3, pressure plate; 4, first laser rangefinder; 41, measuring plate; 51, pushing mechanism; 52, second laser rangefinder; 53, third laser rangefinder; 54, slider; 6, mounting sleeve; 7, sleeve; 8, marking rod; 81, positioning ring; 9, limit rod; 10, extension rod; 101, base plate. DETAILED DESCRIPTION

[0058] The present application is further described in detail below with reference to the embodiments.

[0059] Example 1

[0060] like Figure 1 As shown, this embodiment provides a device for measuring the height and crown width of tobacco plants, the device comprising: a vertically arranged telescopic rod 1;

[0061] A screw rod detachably connected to the left side of the top of the telescopic rod 1 and arranged in the horizontal direction, the screw rod comprising a screw rod 21 and a nut 22;

[0062] A pressing plate 3 is provided on the outer periphery of the screw 21 for pressing against the top of the tobacco plant crown;

[0063] A first laser rangefinder 4 is installed below the nut 22, and the first laser rangefinder 4 is arranged vertically downward;

[0064] A distance measuring assembly is mounted on the telescopic rod 1 on the side facing the first laser rangefinder 4. The distance measuring assembly includes a driving mechanism 51 and a second laser rangefinder 52 and a third laser rangefinder 53 provided on the telescopic end of the driving mechanism 51. The second laser rangefinder 52 is arranged in the horizontal direction for measuring the crown width, and the third laser rangefinder 53 is arranged in the vertical direction for measuring the plant height.

[0065] and a controller, the controller being in communication with the laser rangefinder, the pushing mechanism, and the lead screw, and being configured to control the movement of the pushing mechanism 51 and the lead screw according to a measurement signal from the laser rangefinder;

[0066] The measuring ends of the first laser rangefinder 4 and the third laser rangefinder 53 are flush with the bottom end of the pressing plate 3 to ensure that the measurement references are consistent.

[0067] As a preferred solution of this embodiment, the pushing mechanism 51 may be an electric push rod.

[0068] The screw rod is detachably connected to the left side of the top end of the telescopic rod 1 through the mounting sleeve 6;

[0069] A drive device 13 is provided on the left side of the top of the telescopic rod 1. The drive device 13 is preferably a brake motor. This brake motor is a linear drive unit that integrates a mechanical brake on an electric motor. When the power is cut off or an emergency brake signal is received, the brake spring can quickly apply a preload force, causing the rotating shaft to be reliably locked in a short period of time, thereby preventing the telescopic rod from sliding down or losing control due to its own gravity or external impact, thereby improving the safety and positioning stability of the device. A counterweight is also provided at a position opposite to the drive device 13, that is, on the right side of the top of the telescopic rod 1. This counterweight optimizes the overall center of gravity position by adding an equivalent mass based on the mass and center of gravity distribution of the brake motor and drive components, reducing the overturning moment and vibration of the telescopic rod during lifting or horizontal rotation, and ensuring that the entire measuring device has good stability and reliability under multiple working conditions.

[0070] One end of the screw rod 21 is movably connected to the driving device 13 through a connecting piece, and the other end extends to the far side of the pressing plate 3;

[0071] After the screw 21 brake motor is extended, a sleeve 7 is coaxially sleeved on the outer peripheral surface of the end connected to the drive device 13; one end of the sleeve 7 is fixedly connected to the outer shell of the brake motor, and the other end extends horizontally to the far side of the pressure plate 3;

[0072] The top end of the pressure plate 3 is fixedly connected to the outer wall of the sleeve 7 through a connecting rod 31. A horizontal avoidance hole is provided on the connecting rod 31. The axis of the avoidance hole coincides with the laser emission path of the second laser rangefinder 52 to avoid blocking the measuring light path of the second laser rangefinder 52.

[0073] The distance measuring assembly also includes a slider 54 arranged between the connecting end of the sleeve 7 and the pressure plate 3. The top end of the slider 54 is slidably connected to the outer peripheral wall of the sleeve 7, and the side wall is connected to the telescopic end of the pushing mechanism 51. The second laser rangefinder 52 and the third laser rangefinder 53 are respectively installed on one side and the bottom end of the slider 54 facing the pressure plate 3.

[0074] The bottom end of the telescopic rod 1 is also provided with a spike portion 11, and the top end of the spike portion 11 is hingedly connected to a plurality of legs 111 along the circumference. Each leg 111 can be folded or unfolded relative to the spike portion 11 to improve the support stability of the device at the base of the plant. The spike portion 11 and the legs 111 enhance stability in soft soil in the field.

[0075] As a preferred embodiment of the present invention, the top end of the spike portion 11 is hinged with three legs 111 at equal intervals along the circumferential direction;

[0076] A marker rod 8 is connected to the outer wall of the telescopic rod 1 above the spike 11. This rod 8 is slidably connected to the outer wall of the telescopic rod 1 via a positioning ring 81 and can be positioned and locked at any point in the middle of the telescopic rod 1. Once locked, the rod 8 is positioned directly below the measuring end of the third laser rangefinder 7. The rod 8 can slide and lock along the telescopic rod to accommodate different tobacco plant root heights. The positioning ring 81 is provided with a threaded hole, which allows the rod 8 to be fixed in place by engaging a screw against the outer wall of the telescopic rod 1.

[0077] The side of the pressing plate 3 facing the tobacco plant is provided with a plurality of pressure sensors or flexible tactile sensors for detecting the contact state and posture changes between the pressing plate and the base of the plant in real time to ensure measurement accuracy.

[0078] The first laser rangefinder 4 is mounted below the measuring plate 41 and connected to the nut 22 via the measuring plate 41. The outer peripheral wall of the free end of the sleeve 7 is connected to one end of a limiting rod 9, the other end of which extends through the measuring plate 41 and limits the sliding travel of the measuring plate 41 along the sleeve 7. Due to the presence of the limiting rod 9, the starting position of the measuring plate 41 and the nut 22 is preset on the opposite side of the pressure plate 3. That is, the pressure plate 3 is located between the measuring plate 41, on which the first laser rangefinder 4 is mounted, and the slider 54, on which the second and third laser rangefinders 52 and 53 are mounted.

[0079] The telescopic rod 1 is a manual telescopic rod or an electric telescopic rod; the telescopic rod is also provided with a level bubble 12. The level bubble 12 ensures the verticality of the device and avoids measurement errors caused by tilt.

[0080] In this embodiment, when the telescopic rod 1 is a manual telescopic rod, it is composed of a sleeve rod and an inner rod, wherein the inner rod can slide inside the sleeve rod; at least one longitudinal guide groove is provided on the outer circumference of the sleeve rod, and the inner rod and the sleeve rod are locked by a locking screw. The locking screw can move along the guide groove and be screwed into the outer circumference of the inner rod to achieve relative fixation of the inner rod and the sleeve rod at any position of the sleeve rod, thereby ensuring that the telescopic rod is locked at any desired length and improving the positioning stability of the structure;

[0081] As a preferred embodiment of this embodiment, a longitudinal guide groove is provided on the outer periphery of the sleeve rod.

[0082] Example 2

[0083] like Figure 2As shown, the difference between this embodiment and Example 1 is that the telescopic rod 1 is replaced with an electric push rod telescopic rod, and the fixed end of the corresponding electric push rod telescopic rod is fixed to the upper end of the newly added base plate 101; the lower end of the base plate 101 is connected to an extension rod 10, and the extension rod 10 serves as the bottom supporting member of the electric telescopic rod. The spike portion 11 at the bottom of the telescopic rod 1, the support leg 111 provided at the top of the spike portion 11, the marking rod 8 and the positioning ring 81 and other components are all fixedly connected to the extension rod 10.

[0084] Those skilled in the art will understand that the following examples are intended to illustrate the present invention only and should not be construed as limiting the scope of the present invention. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in the art or in the product specifications were used. Materials or equipment used without manufacturer identification are conventional products that can be purchased.

[0085] Example 3

[0086] This embodiment provides a method for measuring tobacco plant height and crown width using the device described in Example 1 or Example 2, comprising the following steps:

[0087] Step (1): Place the device near the target tobacco plant, insert the spike portion 11 vertically into the soil to ensure it is firm, unfold the legs 111 so that the soles of the legs are close to the soil surface to further stabilize the device; then adjust the telescopic rod 1 to a fully vertical state, that is, the level bubble 12 indicates that the telescopic rod 1 is fully vertical;

[0088] Step (2): Move along the telescopic rod 1 and lock the positioning ring 81 so that the marking rod 8 is located directly below the detection end of the third laser rangefinder 7 and flush with the root of the tobacco plant;

[0089] Step (3): Control the telescopic rod 1 to shorten, so that the pressing plate 3 stops after contacting the top of the tobacco plant from top to bottom, and start the third laser rangefinder 53 to measure the distance H1 between the bottom end of the pressing plate 3 and the marking rod 8, where H1 is the height of the tobacco plant;

[0090] Step (4): Control the push mechanism 51 to extend, driving the second laser rangefinder 52 and the third laser rangefinder 53 to approach the tobacco plant; at the same time, drive the screw rod so that the nut 22 drives the first laser rangefinder 4 to synchronously approach the tobacco plant;

[0091] Step (5): The controller monitors the following data in real time:

[0092] The distance H2 from the nut 22 to the ground measured by the first laser rangefinder 4;

[0093] The real-time distance H1′ between the pressing plate 3 and the marking rod 8 measured by the third laser rangefinder 53;

[0094] The corresponding institution shall be stopped when the following conditions are met:

[0095] If H2≤H1–a, stop the screw;

[0096] If H1'≤H1–a, the pushing mechanism 51 is stopped;

[0097] Where a is the preset threshold;

[0098] As a preferred solution in this embodiment, the value of a is set to 10 cm;

[0099] Step (6): After the screw and the pushing mechanism 51 have stopped, the second laser rangefinder 52 is used to measure the horizontal distance L from the screw and the side wall of the measuring plate 41 to further calculate the crown width L' of the tobacco plant.

[0100] To further eliminate the inherent offset between the installation positions of the first and third laser rangefinders 4 and 53 and the measuring plate 41, this embodiment introduces two fixed compensation parameters b and c based on the original crown width measurement result L to obtain the corrected crown width L′. The calculation relationship is:

[0101] L=L′+b+c

[0102] in:

[0103] L′: original crown amplitude obtained by measuring the horizontal distance from the measuring end of the second laser rangefinder 52 to the side wall of the measuring plate 41;

[0104] b: Compensate for the horizontal offset between the installation point of the first laser rangefinder 4 and the side wall of the measuring plate 41 to ensure a uniform starting point for ranging;

[0105] c: Compensate for the horizontal offset between the installation position of the third laser rangefinder 53 and the side wall of the measurement plate 41 to eliminate the height measurement reference difference.

[0106] Parameters b and c can be determined once through calibration experiments based on the fixed installation distances of the first and third laser rangefinders on the measurement plate 41 (e.g., the clearance between the axis center and the sidewall). These constant values remain constant throughout all subsequent measurements. This ensures that L' truly reflects the actual crown width of the target tobacco plant, unaffected by systematic errors caused by the installation positions of the rangefinders.

[0107] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made thereto in form and detail without departing from the scope defined by the claims of the present application. The dimensions described in the drawings and embodiments are not related to specific physical objects and are not used to limit the scope of protection of the present application. The physical dimensions can be selected and changed according to actual needs.

Claims

1. A device for measuring tobacco plant height and crown width, characterized in that: The device comprises: A telescopic rod (1) arranged vertically; A screw rod detachably connected to one side of the top of the telescopic rod (1) and arranged in a horizontal direction, the screw rod comprising a screw rod (21) and a nut (22), the nut (22) being slidably connected to the outer peripheral wall of the screw rod (21); A pressing plate (3) provided on the outer periphery of the screw (21) for pressing against the top of the tobacco plant crown; a first laser rangefinder (4) mounted below the nut (22), the first laser rangefinder (4) being arranged vertically downward; A distance measuring assembly is mounted on the telescopic rod (1) and faces the first laser distance measuring instrument (4). The distance measuring assembly comprises a driving mechanism (51) and a second laser distance measuring instrument (52) and a third laser distance measuring instrument (53) arranged on the telescopic end of the driving mechanism (51). The second laser distance measuring instrument (52) is arranged in the horizontal direction and is used to measure the crown width. The third laser distance measuring instrument (53) is arranged in the vertical direction and is used to measure the height of the plant. and a controller, the controller being in communication with the laser rangefinder, the pushing mechanism, and the screw rod, and being used to control the movement of the pushing mechanism (51) and the screw rod according to a measurement signal from the laser rangefinder; The measuring ends of the first laser rangefinder (4) and the third laser rangefinder (53) are flush with the bottom end of the pressing plate (3) to ensure that the measurement references are consistent.

2. The device for measuring tobacco plant height and crown width according to claim 1, characterized in that: A driving device (13) is also provided on the top of the telescopic rod (1); One end of the screw rod (21) of the screw rod is movably connected to the driving device (13) through a connecting piece, and the other end extends to the far side of the pressing plate (3); After the screw rod (21) extends from the driving device 13, a sleeve (7) is coaxially sleeved on the outer peripheral surface of the end connected to the driving device 13; one end of the sleeve (7) is fixedly connected to the outer wall of the telescopic rod (1) or the outer shell of the driving device 13, and the other end extends horizontally to the far side of the pressing plate (3); The top end of the pressure plate (3) is fixedly connected to the outer peripheral wall of the sleeve (7) via a connecting rod (31); a horizontal avoidance hole is provided on the connecting rod (31); the axis of the avoidance hole coincides with the laser emission path of the second laser rangefinder (52) to avoid blocking the measuring optical path of the second laser rangefinder (52).

3. The device for measuring tobacco plant height and crown width according to claim 2, characterized in that: The distance measuring assembly further comprises a slider (54) arranged between the connecting end of the sleeve (7) and the pressure plate (3); the top end of the slider (54) is slidably connected to the outer peripheral wall of the sleeve (7), and the side wall is connected to the telescopic end of the pushing mechanism (51); the second laser rangefinder (52) and the third laser rangefinder (53) are respectively installed on one side and the bottom end of the slider (54) facing the pressure plate (3).

4. The device for measuring tobacco plant height and crown width according to claim 1, characterized in that: The bottom end of the telescopic rod (1) is further provided with a spike portion (11), the top end of the spike portion (11) is hingedly connected to a plurality of legs (111) along the circumferential direction, and each leg (111) can be folded or unfolded relative to the spike portion (11) to enhance the support stability of the device at the base of the plant.

5. The device for measuring tobacco plant height and crown width according to claim 1, characterized in that: The outer peripheral wall of the telescopic rod (1) is connected to a marking rod (8) above the spike portion (11); the marking rod (8) is slidably connected to the outer wall of the telescopic rod (1) via a positioning ring (81) and can be positioned and locked at any position in the middle of the telescopic rod (1); after being locked, the marking rod (8) is positioned directly below the measuring end of the third laser rangefinder (7).

6. The device for measuring tobacco plant height and crown width according to claim 1, characterized in that: The side of the pressing plate (3) facing the tobacco plant is provided with a plurality of pressure sensors or flexible tactile sensors for real-time detection of the contact state and posture change between the pressing plate and the plant base to ensure measurement accuracy.

7. The device for measuring tobacco plant height and crown width according to claim 1, characterized in that: The first laser rangefinder (4) is connected to the bottom of the nut (22) via a measuring plate (41); the outer peripheral wall of the free end of the sleeve (7) is also connected to one end of a limiting rod (9), the other end of the limiting rod (9) passes through the measuring plate (41) and is used to limit the sliding stroke of the measuring plate (41) on the sleeve (7), wherein the measuring plate (41) is directly opposite to the detection end of the second laser rangefinder (52).

8. The device for measuring tobacco plant height and crown width according to claim 1, characterized in that: The telescopic rod (1) is a manual telescopic rod or an electric telescopic rod; a leveling bubble (12) is also provided on the telescopic rod.

9. A method for measuring tobacco plant height and crown width using the device according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step (1): placing the device near a target tobacco plant, inserting the spike portion (11) vertically into the soil to ensure that it is secure, unfolding each leg (111) so that the soles of the legs are in close contact with the soil surface to further stabilize the device; and then adjusting the telescopic rod (1) to a fully vertical state; Step (2), moving along the telescopic rod (1) and locking the positioning ring (81), so that the marking rod (8) is located directly below the detection end of the third laser rangefinder (7) and flush with the root of the tobacco plant; Step (3), controlling the telescopic rod (1) to shorten, so that the pressing plate (3) contacts the top of the tobacco plant from top to bottom and then stops, starting the third laser rangefinder (53) to measure the distance H1 between the bottom end of the pressing plate (3) and the marking rod (8), wherein H1 is the height of the tobacco plant; Step (4), controlling the pushing mechanism (51) to extend, driving the second laser rangefinder (52) and the third laser rangefinder (53) to approach the tobacco plant; simultaneously driving the screw rod to cause the nut (22) to drive the first laser rangefinder (4) to synchronously approach the tobacco plant; Step (5): The controller monitors the following data in real time: A distance H2 from the nut (22) to the ground measured by a first laser rangefinder (4); A real-time distance H1' from the pressure plate (3) to the marking rod (8) measured by a third laser rangefinder (53); The corresponding institution shall be stopped when the following conditions are met: If H2≤H1–a, stop the screw; If H1'≤H1–a, the pushing mechanism (51) is stopped; Where a is the preset threshold; Step (6): After the screw and the pushing mechanism (51) have stopped, the horizontal distance L' from the screw and the side wall of the measuring plate (41) is measured by the second laser rangefinder (52), and the crown width L of the target tobacco plant is calculated.

10. The method according to claim 9, characterized in that The method for calculating the crown width L of the target tobacco plant is: L=L′+b+c in: L′: the horizontal distance from the measuring end of the second laser rangefinder 52 to the side wall of the measuring plate 41; b: Compensate for the horizontal offset between the mounting point of the first laser rangefinder 4 and the side wall of the measuring plate 41; c: Compensate for the horizontal offset between the installation position of the third laser rangefinder 53 and the side wall of the measurement plate 41 .

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