A device and method for measuring multiple states of area and profile of a corn leaf in vivo

Abstract

The present application relates to the technical field of plant leaf geometry measurement, and discloses a kind of living corn leaf section multi-state area and profile measurement device and method.Open measurement window two sides are equipped with fixed end and longitudinal floating end, floating end allows leaf section to follow flattening process along length direction from dynamic micro shift while limiting lateral displacement and rotation;Window is equipped with flexible flattening assembly and reference support assembly that can give way up and down.Measurement is sequentially collected in non-contact natural state, controlled reference state and release state after the exit of upper and lower components from leaf envelope on both sides, and area, profile and feature point position are compared under the same coordinate.Only when area recovery error, profile recovery error, position slip, peak force and maximum stroke do not exceed corresponding threshold value respectively and no damage occurs, reference state data is retained.

Description

Technical Field

[0001] This invention relates to the field of plant leaf geometry measurement technology, specifically to a device and method for measuring the projected area, outline and positional features of a living corn leaf segment under multiple states, and for determining whether the reference measurement process caused mechanical disturbance by using the morphological recovery results after release. Background Technology

[0002] Maize leaves exhibit varying degrees of lateral curling during water deficit, high temperatures, rehydration, and other environmental changes. Leaf curling not only alters the leaf's projected width, projected area, and boundary profile but also affects phenotypic responses such as light orientation, boundary layer conditions, and leaf surface temperature. Therefore, in studies of maize drought resistance phenotypes, physiological ecology, and heat-drought responses, it is typically necessary to repeatedly measure the same living leaf still attached to the plant and compare its naturally curled state with a reference unfolded state under specific conditions to minimize the influence of leaf size, leaf position, and individual plant differences on the measurement results.

[0003] In the prior art, CN202329577U discloses a live-cell leaf area measurement device for broadleaf plants, which clamps the leaf to be measured with a base plate and a transparent cover plate and keeps it flat before taking pictures and measuring; CN108120374A discloses a non-destructive method for calculating the leaf area of ​​plants by using a leaf clamp for acquiring plant leaf area data, which uses hinged upper and lower cover plates and transparent materials to flatten the plant leaf before acquiring images; CN113099065B discloses a handheld portable plant leaf rolling adsorption scanning device and its scanning method, which keeps the leaf stable in the scanning area through a glass fiber mesh and a vacuum adsorption structure. The above technologies can provide relatively stable imaging conditions for leaf contour extraction and area calculation, but their common feature is that the leaf comes into contact with the base plate, cover plate, flexible surface or adsorption support surface during the measurement process. Therefore, it is difficult to obtain the natural curled shape of the leaf under the condition that there is no contact between the upper and lower sides of the leaf during the first acquisition, and it does not form a continuous measurement process in which the same live leaf segment enters the controlled reference state from the natural state, and then the upper and lower components are released from the leaf envelope for retesting.

[0004] On the other hand, CN108254621A discloses a method and apparatus for measuring plant physiological resistance under a specific clamping force, using a specified clamping force to perform contact measurement on plant leaves; US8584510B2 discloses a method and apparatus for measuring plant sample pressure parameters, selecting the clamping pressure through clamping pressure pulses and relaxation responses after pressure release, with the pressure response of leaves as the detection object; CN115937151B discloses a method for determining the degree of crop leaf curling, obtaining point clouds through three-dimensional reconstruction of leaf images and calculating leaf area and projected area; CN120976293B discloses a method and system for calculating the curling degree of maize leaves based on image processing, using multi-position images, three-dimensional reconstruction, and projected area ratio to characterize maize leaf curling. The aforementioned solutions involve clamping force control, pressure relaxation, or image geometric measurement, but none of them involve generating a physical reference morphology on the same living leaf segment using a fixed end and a longitudinally floating end, and determining whether the previous reference morphology data is retained based on the area, contour, and feature point recovery results under the same coordinates after the upper and lower components return to the yielding position and leave the leaf envelope.

[0005] For curled leaves still connected to the plant, the relationship between the arc length and projected length changes as the leaf segment transitions from a curved to a more flattened state. If both ends of the measurement area are rigidly locked or actively tensioned, the flattening action may superimpose longitudinal stretching onto lateral flattening, causing the resulting reference morphology to be subjected to two mechanical forces simultaneously. Therefore, while maintaining lateral positioning and measurement coordinates, it is necessary to allow one end to be driven by the change in the projected length of the leaf segment to make a slight, passive movement along the length direction, and to avoid continuous loading of the return spring or active traction along the leaf length direction.

[0006] Existing methods for measuring blade area, curling, or pressure response also present another problem: after the flattening, adsorption, or clamping process, if the support remains in contact with the blade, or if only the relaxation of the pressure signal is observed, it is impossible to directly determine whether the previously obtained geometric reference data is accompanied by overall slippage, local indentation, creases, or residual deformation. If different camera positions, scales, or cropped areas are used for the natural and released states, positional changes may also be included in the blade morphology changes.

[0007] Therefore, a device and method for measuring the area and profile of live maize leaf segments is needed, ensuring that the middle leaf segment under test is in a non-contact state on both sides during natural collection and release retesting; within the same leaf segment and the same measurement coordinates, a position reference is established by a fixed end, and a longitudinal floating end moves slightly following the change in the projected length of the leaf segment as the reference shape is formed; after the reference shape is collected, the upper and lower components return to their retraction positions and leave the leaf envelope, and the recovery results of area, profile, and feature point positions are used, combined with peak force, maximum stroke, and damage records, to determine whether the reference shape data should be retained. Summary of the Invention

[0008] The purpose of this invention is to provide a multi-state area and contour measurement device and method for live corn leaf segments. Before mechanical contact, natural morphological data with no contact on both sides is obtained. When the reference morphology is formed, the longitudinal floating end is allowed to move slightly following the change in the projected length of the leaf segment. After measurement, the upper and lower components are returned to the yielding position and leave the leaf envelope. By comparing the area, contour and feature point positions of the natural measurement state and the released measurement state under the same coordinate, it is determined whether the data of the reference measurement state should be retained.

[0009] To achieve the above objectives, the present invention provides a multi-state area and profile measurement device for live corn leaf segments, including a frame, an open measurement window, a first leaf segment positioning component, a second leaf segment positioning component, a lower reference support component, a lower lifting and guiding component, an upper flexible flattening component, an upper guiding drive component, an elastic force limiting component, a force detection component, a rigid distribution plate, an independent mechanical limit component, a measurement component, a calibration mark, and a recording and control component.

[0010] The frame is used to establish a unified mechanical coordinate system. The open measurement window is located in the middle of the frame and is used to accommodate the natural curled envelope of the live blade segment to be measured. A first blade segment positioning component and a second blade segment positioning component are positioned on either side of the open measurement window along the blade's length direction. The first blade segment positioning component acts as a fixed end, limiting its longitudinal and lateral positions, while the second blade segment positioning component acts as a longitudinally floating end, limiting lateral displacement and rotation and allowing for passive micro-movement along the length direction. During the formation of the reference shape, the second blade segment positioning component can move along the length direction due to changes in the projected length of the blade segment, without applying longitudinal tension to the blade segment through a return spring or active traction.

[0011] The lower reference support assembly is located below the open measurement window and can move between the lower retracted position and the reference support position; the upper flexible flattening assembly is located above the open measurement window and can move between the upper retracted position and the flattening working position. In the natural measurement state and the released measurement state, both the upper and lower working assemblies are located in their respective retracted positions and away from the blade envelope, so that the middle blade segment to be measured maintains an air gap with the upper and lower working assemblies; in the reference measurement state, the lower reference support assembly enters the reference support position, and the upper flexible flattening assembly enters relative to it under the condition of recording the applied force and stroke, while the longitudinal floating end allows for passive micro-movement in the blade segment length direction, so that the same blade segment forms a reference shape.

[0012] Preferably, the actual force transmission path of the upper flexible flattening component sequentially includes an upper guide drive component, an elastic force limiting component, a force detection component, a rigid distribution plate, and a flexible membrane frame. The elastic force limiting component is used to absorb part of the driving displacement and limit the rate of increase of the force. The force detection component is located in the actual force transmission path to record the force acting on the flexible flattening component. The rigid distribution plate is used to distribute the concentrated load to the flexible planar component.

[0013] The independent mechanical limit assembly is independent of the force detection device and software control loop, and is used to form a mechanical hard stop. Even if the force detection device, controller or operator fails to stop the drive in time, the independent mechanical limit assembly can still limit the maximum descent stroke or the minimum distance between the upper and lower working components.

[0014] The measurement assembly is fixed to the frame and preferably includes a top-view camera; calibration marks are arranged around the open measurement window. In the natural measurement state, reference measurement state, and released measurement state, the camera position, focal length, calibration marks, and measurement area remain constant relative to the frame, allowing direct registration and comparison of areas, contours, and feature points in different states. The measurement assembly also includes at least one of a side-view camera, a depth measurement module, a non-contact infrared thermography module, and a diffuse light source. When a non-contact infrared thermography module is used, leaf temperature acquisition is completed before any support or flattening contact occurs to avoid mechanical contact altering the leaf temperature measurement conditions.

[0015] The recording and control component records status identifiers, image numbers, peak force, maximum stroke, holding time, and abnormal events. It also compares the natural measurement state data and release measurement state data obtained for the same blade segment under the same measurement coordinates to obtain area recovery error, contour recovery error, and position slip. The area and contour data of the reference measurement state are only retained when the area recovery error, contour recovery error, position slip, peak force, and maximum stroke of the reference measurement state do not exceed their respective thresholds, and no scratches, creases, indentations, tears, increased curling, or independent mechanical limit failure occur.

[0016] The present invention also provides a method for measuring the area and contour of a live corn leaf segment in multiple states, which includes, in sequence, device inspection, leaf segment installation, acquisition of natural state without contact on both sides, entry with lower support, formation of reference state under longitudinal floating conditions, acquisition of reference state, retraction of upper and lower components, acquisition of release state, comparison of recovery and slippage, and determination of data retention.

[0017] Compared with the prior art, the present invention can produce the following effects:

[0018] 1. In the natural measurement state, both the upper flexible flattening component and the lower reference support component are removed from the blade envelope, and the middle part of the blade segment to be measured remains suspended, thereby obtaining the area and contour data of the blade under natural curling conditions before mechanical contact, thus reducing the pre-interference of the base plate, cover plate or adsorption surface.

[0019] 2. The fixed end is used to establish the position reference, and the longitudinal floating end is used to limit the lateral displacement and rotation. During the formation of the reference shape, it moves slightly along the length direction as the projected length of the blade segment changes, without applying active longitudinal stretching to the blade segment, so that the lateral flattening process is less affected by the superimposed longitudinal traction effect.

[0020] 3. The series-connected elastic force limiter, force detection device, and rigid distribution plate are used to record the actual force transmission process; the independent mechanical limit is separated from the sensor and software control, and continues to limit movement if the force detection device, controller, or operator fails to stop the drive in time. Therefore, the peak force and maximum stroke of each reference measurement state can be recorded, while retaining the mechanical hard stop.

[0021] 4. After the reference measurement is completed, both the upper and lower working components exit the blade envelope and re-acquire the release measurement state under the same measurement coordinates as the natural measurement state. The area, contour, and feature point positions of the natural and release states are used to check whether the blade segment has recovered and whether slippage has occurred, and directly participate in the determination of the retention of the reference measurement data.

[0022] 5. The frame, measurement components, calibration marks, and measurement area remain unchanged under the three states, which facilitates direct comparison of the same leaf segment under the same coordinate system and can be used for multiple cycles of repeated observation of the same living leaf during intraday changes, drought, and rehydration processes. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the cross-section of the present invention in a natural, non-contact state.

[0025] Figure 3 This is a schematic diagram of the controlled reference state cross-section of the present invention;

[0026] Figure 4 This is a schematic diagram of the principle of releasing the measurement state cross-section of the present invention;

[0027] Figure 5 This is a top view showing the positioning relationship between the fixed end and the longitudinal floating end of the present invention;

[0028] Figure 6 This is a schematic diagram of the series force transmission path and independent mechanical limiting principle of the present invention;

[0029] Figure 7 This is a flowchart of the multi-state measurement and data retention determination process of the present invention.

[0030] Explanation of reference numerals in the attached drawings: 1. Frame; 2. Open measurement window; 3. First blade segment positioning assembly; 4. Second blade segment positioning assembly; 5. Lower reference support assembly; 6. Lower lifting and guiding assembly; 7. Upper flexible flattening assembly; 8. Upper guide drive assembly; 9. Elastic force limiting component; 10. Force detection component; 11. Rigid distribution plate; 12. Independent mechanical limit assembly; 13. Measurement assembly; 14. Calibration mark; 15. Live blade segment to be measured; 16. Longitudinal micro-slide; 17. Soft support; 18. Diffuse light source; 19. Recording and control assembly. Detailed Implementation

[0031] The present invention will now be described in conjunction with the accompanying drawings and specific embodiments. These embodiments are used to illustrate the device structure and measurement process and do not limit the scope of the claims. While maintaining the above structural relationships and operational sequence, specific materials, driving methods, dimensions, and acquisition parameters may be replaced or adjusted accordingly.

[0032] The following implementation describes the device operation and data acquisition process in the order of natural measurement state, reference measurement state, and release measurement state.

[0033] Example 1: Structure of the measuring device

[0034] See Figure 1 This embodiment provides a multi-state area and profile measurement device for live corn leaf segments. The frame 1 is made of aluminum profile, rigid plate, or other materials that can maintain structural stability, and an open measurement window 2 is formed in the middle of the frame 1. The length direction of the open measurement window 2 is set along the main vein direction of the live leaf segment 15 to be measured, and the size of the open measurement window 2 should be able to cover the main measurement area of ​​the leaf segment to be measured and accommodate its natural curl envelope.

[0035] A first blade segment positioning component 3 is installed on one side of the open measurement window 2, and a second blade segment positioning component 4 is installed on the other side. The first blade segment positioning component 3 serves as the fixed end and adopts one of the following: a U-shaped support, shallow groove, elastic light clamp, or flexible ring with silicone, elastomer, or other soft lining. Its function is to restrict the longitudinal and lateral positions of the blade segment outside the measurement area and establish a coordinate reference. The second blade segment positioning component 4 serves as the longitudinal floating end, and its support is installed on the longitudinal micro-slide 16. The longitudinal micro-slide 16 can adopt a slide, linear guide, roller slide, or other low-friction guiding structure, allowing only slight movement along the blade length direction, and is equipped with end stops and anti-detachment structures. The second blade segment positioning component 4 restricts the lateral displacement and rotation of the blade, but does not provide a return spring for longitudinal tensioning of the blade. When the blade segment transitions from a naturally curled state to a reference shape and the projected length changes, the longitudinal micro-slide 16 is driven by the blade segment to produce a driven micro-movement.

[0036] See Figures 2 to 4The lower reference support assembly 5 is located below the open measurement window 2 and moves between the lower retracted position and the reference support position via the lower lifting and guiding assembly 6. The lower reference support assembly 5 is preferably made of transparent acrylic or glass with rounded edges. The lower lifting and guiding assembly 6 employs one of the following structures: double guide pillars, four-point guide, linear guide rail, or other structures capable of maintaining the attitude of the reference support surface, allowing the lower reference support assembly 5 to enter the reference support position vertically, reducing scratches caused by lateral sweeping across the blade edge.

[0037] The upper flexible flattening assembly 7 is located above the open measurement window 2. It includes a rigid outer frame and a transparent flexible membrane or other flexible planar element that can evenly distribute pressure, uniformly tensioned on the rigid outer frame. The upper flexible flattening assembly 7 moves between an upper retracted position and a flattening working position via an upper guide drive assembly 8. The upper guide drive assembly 8 employs one of the following methods: manual lead screw, electric lead screw, linear actuator, rack and pinion, or other controllable linear drive, and is equipped with guides to limit the attitude changes of the flexible flattening assembly 7.

[0038] See Figure 6 In a preferred embodiment, the force transmission path from the upper guide drive assembly 8 to the tested living blade segment 15 is as follows: upper guide drive assembly 8, elastic force limiting member 9, force detection member 10, rigid distribution plate 11, and upper flexible flattening assembly 7. The elastic force limiting member 9 is a compression spring, leaf spring, or other elastic element with known or calibrated stiffness; the force detection member 10 is a pressure load sensor or a calibrated push-pull force gauge; the rigid distribution plate 11 is used to distribute the concentrated load output by the force detection member 10 to the flexible membrane frame. The force detection member 10 is positioned in the actual force transmission path to avoid any main load bypasses that bypass the force detection member 10.

[0039] The independent mechanical limiting component 12 is located outside the force transmission path, and its mechanical stop part adopts at least one of the following: adjustable limiting screw, stop block, limiting post, or stop surface. The independent mechanical limiting component 12 is independent of the force detection component 10 and the software control, and forms a mechanical hard stop by limiting the maximum downward stroke of the upper flexible flattening component 7, the maximum upward stroke of the lower reference support component 5, or the minimum distance between the upper and lower components.

[0040] Measurement component 13 is configured to correspond to open measurement window 2. One configuration is a fixed top-view camera, which is fixedly connected to the frame 1 via a rigid bracket. After focusing, the camera maintains its position and focal length unchanged in the same multi-state measurement cycle. Multiple calibration marks 14 are fixedly set around open measurement window 2. The calibration marks 14 are located in positions not obstructed by the live leaf segment 15 to be measured, and are used for scale calibration, three-state image registration, and feature point displacement calculation. Measurement component 13 also includes at least one of a side-view camera, a depth measurement module, and a non-contact infrared temperature measurement module to obtain profile height, spatial morphology, or pre-contact leaf temperature information. When an infrared temperature measurement module is configured, leaf temperature acquisition should be completed before the lower reference support component 5 or the upper flexible flattening component 7 comes into contact with the live leaf segment 15 to be measured. A diffuse light source 18 that does not enter the force transmission chain is set below the lower reference support component 5 to reduce fluctuations in leaf edge segmentation under the reference measurement state.

[0041] The recording and control component 19 can be an industrial computer, a microcontroller, a data acquisition module, or a manual recording device, used to establish the correspondence between the status number and the image number of a measurement cycle, and to record the force value, stroke, holding time, abnormal events, and data retention markers.

[0042] Example 2: Multi-state area and profile measurement method

[0043] See Figure 7 When using the device of Example 1 to measure the area and contour of the same live corn leaf segment, the following steps are performed.

[0044] Step S1, Device Reset and Inspection. Place the upper flexible flattening assembly 7 in the upper retracted position and the lower reference support assembly 5 in the lower retracted position. Check the zero-point status of the open measurement window 2, the independent mechanical limit assembly 12, the calibration mark 14, and the force detection element 10.

[0045] Step S2, install the leaf segment. Select a corn leaf that is still connected to the plant, place one side of the segment to be tested in the soft groove 17 of the first leaf segment positioning component 3, and the other side in the soft groove 17 of the second leaf segment positioning component 4, so that the longitudinal micro-slider 16 is near the middle of the movable stroke, without actively tightening the leaf, and so that the middle leaf segment to be tested spans the open measurement window 2.

[0046] Step S3: Collect data in its natural state. See also... Figure 2 Visible air gaps were confirmed between the middle blade segment under test, the upper flexible flattening component 7, and the lower reference support component 5 through side-view observation, a side-view camera, or other methods. Subsequently, the measurement component 13 acquired images of the natural measurement state to obtain the projected area in the natural state. Natural projection width Natural outline and multiple initial feature point coordinates If a non-contact infrared temperature measurement module is configured, the leaf temperature will be collected before any mechanical contact occurs in this step.

[0047] Step S4, lower support entry. Drive the lower reference support assembly 5 slowly into the reference support position along the guide direction. If the edge of the reference support plate contacts the curled blade edge first and generates a lateral push, exit and record an entry path abnormality; if the above situation does not occur, allow the lower reference support assembly 5 to reach the reference support position.

[0048] Step S5: Establish a reference state. The upper flexible flattening assembly 7 is slowly lowered along the guide direction. The force detection component 10 records the applied force and the stroke of the upper assembly. The elastic force limiting component 9 limits the rate of force increase, and the independent mechanical limiting component 12 limits the limit stroke or minimum distance. As the blade segment gradually flattens, the second blade segment positioning component 4 maintains lateral positioning and, driven by the change in the projected length of the blade segment, moves the longitudinal micro-slide 16 along the blade length direction. The process stops when any of the following stopping conditions is met: preset reference shape, preset peak force, maximum permissible stroke, force jump, or independent mechanical limiting.

[0049] Step S6: Collect reference status. See also... Figure 3 During the holding time required to complete imaging, reference state data is acquired using the same camera, focal length, calibration mark 14, and measurement area as in step S3 to obtain the reference projected area. Reference projection width And reference profile, and record peak force Maximum travel And the retention time. The reference measurement state is used to provide a controlled physical reference, and its measurement data must be checked after release to determine whether to retain it.

[0050] Step S7, upper and lower components retract. After the reference measurement state is collected, the upper flexible flattening component 7 is first returned to the upper retracted position, and then the lower reference support component 5 is returned to the lower retracted position, until both upper and lower working components are removed from the blade envelope of the blade segment to be measured, and the middle blade segment to be measured is no longer supported, pressed or flattened.

[0051] Step S8: Collect the release status. See [link / reference] Figure 4 At one or more preset time points after release, images of the release status are acquired to obtain the post-release state. Projected area at time Release the outline and the corresponding feature point positions The preset time points are one or more of 0 s, 10 s, 30 s, and 60 s after release. The camera, calibration mark 14, and measurement area remain unchanged, so that the release measurement state and the natural measurement state are registered in the same coordinate system.

[0052] Step S9: Compare recovery and slippage. Compare the projected area, contour, and corresponding feature points of the natural measurement state and the release measurement state, calculate the area recovery error, contour recovery error, and maximum position slippage, and check whether the peak force, maximum stroke, and whether scratches, creases, indentations, tears, increased curling, or independent mechanical limit failures occurred during the entire action process as recorded in step S5.

[0053] Step S10, data retention determination. If the area recovery error, contour recovery error, maximum position slip, peak force, and maximum stroke do not exceed their respective thresholds and no abnormality described in step S9 occurs, the reference measurement state area and contour data obtained in step S6 are retained; if any condition is not met, the reference measurement state data for this time is not retained, and the corresponding abnormality is recorded.

[0054] Example 3: Data Calculation and Data Retention Determination

[0055] Let the projected area of ​​the natural measurement state be... The projected area of ​​the reference measurement state is After release The projected area at time is The projected widths of the natural measurement state and the reference measurement state are respectively and The blade profiles in the natural measurement state and the released measurement state are respectively... and ;No. The positions of the corresponding feature points in the natural measurement state and the released measurement state are respectively and .

[0056] Area recovery error is calculated using the following formula:

[0057]

[0058] This index is used to evaluate the degree to which the projected area of ​​the blade recovers relative to the natural measurement state after a reference measurement operation.

[0059] Maximum position slip Calculate using the following formula:

[0060]

[0061] The double vertical lines represent the distance within the same calibration coordinate system. This indicator is used to determine whether the fixed, floating positioning, and reference state formation processes cause overall or partial positional movement of the tested blade segment.

[0062] Contour restoration error is calculated using the following formula:

[0063]

[0064] in, The preset contour distance function can be selected from one of the following: average boundary distance, Hausdorff distance, contour overlap error, or other geometric quantities that can reflect the degree of deviation between the natural contour and the released contour.

[0065] An executable data retention condition is that the peak force, maximum stroke, maximum position slip, area recovery error, and profile recovery error are simultaneously satisfied:

[0066]

[0067] Furthermore, if there are no scratches, creases, indentations, tears, increased curling, or independent mechanical limit failures, the data of the reference measurement state is retained; otherwise, it is not retained and is recorded as a suspected mechanical disturbance. The above-mentioned preset thresholds are determined through repeated no-load tests of the device, biomimetic flexible strip tests, and pre-tests with attached living blades, and it is not required that the same fixed values ​​be used in all embodiments.

[0068] After the data from the reference measurement state meet the above retention conditions, research phenotypic indicators can be further calculated using data from the natural measurement state and the reference measurement state. For example, the cross-sectional curl index can be calculated using the following formula:

[0069]

[0070] The projection loss rate can be calculated using the following formula:

[0071]

[0072] The above indicators are used to further calculate the multi-state area and width data, without changing the multi-state area and contour measurement, release and reset, and data retention judgment process of this invention.

[0073] Example 4: Structural Parameters and Alternative Implementation Methods

[0074] In one prototype example, the length of the open measurement window 2 is 120–180 mm, preferably about 150 mm, and the width is about 120 mm; the total stroke of the longitudinal micro-slide 16 is about 20 mm, with the initial position located near the middle of the stroke. In both the natural measurement state and the released measurement state, the air gap between the upper and lower working components and the actual envelope of the blade is adjusted according to the degree of blade curling, for example, reserving at least 10 mm of space outside the actual envelope of the blade, and confirming no contact by side observation.

[0075] The lower reference support assembly 5 can be made of transparent acrylic sheet or glass plate with a thickness of about 3 to 5 mm; the upper flexible flattening assembly 7 can be made of PET transparent film with a thickness of about 0.05 to 0.10 mm, or transparent TPU or other flexible sheet materials. The force detection component 10 uses a compressive sensor with a range of 0 to 20 N and a resolution of not less than 0.05 N as a procurement specification example, but this range does not mean that a force of up to the upper limit of the range can be applied to the blade.

[0076] When establishing the reference measurement state, the load is applied slowly by gradually increasing the equivalent force or equivalent small displacement by approximately 0.25 to 0.50 N, and stopping is based on achieving the desired reference shape, rather than continuing to apply pressure to reach a fixed force value. The reference measurement state is maintained for a short time required to complete imaging, for example, 2 to 5 seconds. The dimensions and parameters described above are exemplary implementation parameters and do not constitute a necessary limitation on the scope of protection of this invention.

[0077] The specific structures of the first blade segment positioning component 3 and the second blade segment positioning component 4 are determined according to the blade size and measurement environment, as long as the relationship of establishing a coordinate reference at the fixed end, maintaining lateral positioning at the floating end, and allowing for slight longitudinal slippage can be maintained. The movement mode of the lower reference support component 5 and the upper flexible flattening component 7 adopts a sequential movement of lower part rising first and upper part falling laterally, or adopts a coordinated relative movement; as long as the natural measurement state and the released measurement state can form a double-sided non-contact space, the reference measurement state can be formed under controlled force and stroke conditions, and can return to the yielding position and leave the blade envelope after measurement, it is acceptable.

[0078] Similarly, in one embodiment, the measuring component 13 employs a single top-view camera; in another embodiment, the measuring component 13, in addition to the top-view camera, is also equipped with at least one of a side-view camera, a depth sensor, or other geometric measurement units. The recording and control component 19 employs an automatic controller in one embodiment, and a combination of manual operation and data recording in another. As long as multi-state area, contour, and position data can be obtained, and the data retention is determined based on the recovery results after release, the device structure and measurement steps described above can be implemented.

[0079] Example 5: Threshold Determination, Repeated Measurement Verification, and Anomaly Handling

[0080] To determine the data retention threshold, a tiered testing approach can be used to screen device parameters. The first tier uses bladeless or biomimetic flexible strips, repeatedly checking for jamming in vertical movement, continuity of the force transmission path, presence of load bypass in the force detection components, parallelism of the upper and lower reference surfaces, whether the longitudinal micro-slide can move along the blade length, and whether the independent mechanical limiter can achieve a mechanical hard stop. If the independent mechanical limiter fails this tier of testing, the device will not proceed to the live blade test.

[0081] The second layer uses detached fresh leaf segments for mechanical adaptation, comparing and referencing the support plate material, flexible membrane material, membrane tension, soft tray size, and entry paths of upper and lower components, without directly providing a threshold for the living leaf. The third layer uses living leaves still connected to the plant, covering different degrees of natural curling and performing repeated measurements on the same leaf. Peak force, maximum stroke, residual height of the reference morphology, area recovery error between the natural measurement state and the released measurement state, contour recovery error, feature point slippage, and the measurement dispersion of multiple cycles on the same leaf are recorded. Based on this, the data retention is selected to determine the preset threshold required.

[0082] During the measurement process, abnormal modes can be categorized into at least the following: entry path scraping, longitudinal floating end jamming, off-center loading or sudden force jumps, insufficient formation of the reference shape, failure of independent mechanical limit, position slippage or insufficient recovery, visible damage, and failure of optical boundary segmentation. When entry path scraping, failure of independent mechanical limit, or visible damage occurs, the current cycle should be stopped and reference measurement data should not be retained. When floating end jamming, off-center loading, sudden force jumps, or insufficient recovery occur, measurements can be repeated after ruling out causes such as guidance, membrane tension, positioning, and holding time. For optical anomalies such as membrane wrinkles, glare, or unstable boundary segmentation, the mechanical condition assessment results and image quality assessment results should be recorded separately to avoid confusing image quality issues with mechanical disturbance issues.

[0083] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for measuring the area and contour of a live corn leaf segment in multiple states, characterized in that, include: A frame (1) is provided, with an open measurement window (2) formed in the middle of the frame (1); a first blade segment positioning component (3) is fixedly disposed on one side of the open measurement window (2) along the length direction of the live blade segment (15) to be measured, and has a first positioning part that cooperates with the live blade segment (15) to be measured; a second blade segment positioning component (4) is disposed on the other side of the open measurement window (2) along the length direction of the live blade segment (15) to be measured and is mounted on a longitudinal micro slide (16), the longitudinal micro slide (16) being positioned along the length direction of the live blade segment (15) to be measured. The guide pair is connected to the frame (1), and the guide pair has translational freedom along the length direction of the live blade segment (15) to be measured. The second blade segment positioning component (4) has a second positioning part arranged opposite to the first positioning part. The lower reference support component (5) is arranged below the open measurement window (2) and connected to the frame (1) through the lower lifting and guide component (6). The travel of the lower reference support component (5) includes the lower retraction end position and the reference support end position. The upper flexible flattening component (7) is arranged on the frame (1). Above the open measurement window (2), it is connected to the frame (1) via the upper guide drive assembly (8). The travel of the upper flexible flattening assembly (7) includes the upper retraction end position and the flattening working end position. The force control assembly is connected in series between the drive output end of the upper guide drive assembly (8) and the upper flexible flattening assembly (7), and includes at least an elastic force limiting component (9) and a force detection component (10). The independent mechanical limit assembly (12) is set separately from the force detection component (10) and its control circuit. The component (12) is located on the movement path of the upper flexible flattening component (7) and / or the lower reference support component (5) and has a mechanical stop that abuts against the corresponding moving part; the measuring component (13) is fixedly installed on the frame (1), and its measuring area covers the open measuring window (2), and calibration marks (14) are fixedly installed around the open measuring window (2); and the recording and control component (19) is electrically connected to the measuring component (13) and the force detection component (10) respectively.

2. The multi-state area and contour measurement device for live corn leaf segments according to claim 1, characterized in that, The first positioning part includes a first groove and a first retaining member with a soft lining; the second positioning part includes a second groove and a second retaining member with a soft lining; the guide pair of the longitudinal micro slide (16) is one of a slide groove pair, a linear guide pair or a roller guide pair, and a stroke stop structure and an anti-detachment structure are respectively provided at both ends along the length direction of the live blade segment (15) to be tested.

3. The multi-state area and contour measurement device for live corn leaf segments according to claim 1, characterized in that, The lower reference support assembly (5) includes a transparent reference support plate, which is connected to the lower lifting and guiding assembly (6). The guiding direction of the lower lifting and guiding assembly (6) intersects with the plane where the open measurement window (2) is located. The periphery of the transparent reference support plate is provided with a rounded part.

4. The multi-state area and contour measurement device for live corn leaf segments according to claim 1, characterized in that, The upper flexible flattening component (7) includes a rigid outer frame and a transparent flexible film or transparent flexible surface piece tensioned on the rigid outer frame; the rigid outer frame is connected to the moving end of the upper guide drive component (8).

5. The multi-state area and contour measurement device for live corn leaf segments according to claim 4, characterized in that, The elastic force limiting member (9), the force detection member (10), the rigid distribution plate (11) and the upper flexible flattening component (7) are arranged sequentially from the drive output end of the upper guide drive assembly (8) to the force transmission path of the upper flexible flattening component (7); the mechanical stop of the independent mechanical limiting assembly (12) includes at least one of the following: a limiting screw, a stop block, a limiting post or a stop surface, and intersects with the movement path of the upper flexible flattening component (7), the lower reference support assembly (5) or its corresponding moving part.

6. The multi-state area and contour measurement device for live corn leaf segments according to claim 1, characterized in that, The measurement assembly (13) includes at least a top-view camera fixed to the frame (1) by a rigid bracket, the imaging field of view of the top-view camera covering the open measurement window (2); the calibration mark (14) is fixedly disposed around the open measurement window (2) and located within the imaging field of view; the measurement assembly (13) also includes at least one of a side-view camera, a depth measurement module, a non-contact infrared temperature measurement module and a diffuse light source (18).

7. A method for measuring the area and profile of a live maize leaf segment in multiple states, characterized in that, Includes the following steps: S1, place the upper flexible flattening component (7) and the lower reference support component (5) in their respective retracted positions, and check the measuring component (13), force detection component (10), independent mechanical limit component (12), and calibration mark (14); S2, set the first blade segment positioning component (3) and the second blade segment positioning component (4) on both sides of the open measuring window (2) along the length direction of the live blade segment (15) to be measured, respectively. The first blade segment positioning component (3) restricts the longitudinal and lateral positions of the live blade segment (15) to be measured, and the second blade segment positioning component (4) restricts the lateral displacement and rotation of the live blade segment (15) to be measured and allows it to move slightly along the length direction, so that the live blade segment to be measured... The middle part of segment (15) is placed across the open measurement window (2), and the second blade segment positioning component (4) is allowed to have free movement in the blade length direction; S3, confirm that the middle part of the live blade segment (15) to be measured, the upper flexible flattening component (7) and the lower reference support component (5) maintain an air gap, and collect the projected area, contour and feature point position data of the natural measurement state before mechanical contact occurs; S4, make the lower reference support component (5) enter the reference support position along the guide direction; S5, make the upper flexible flattening component (7) enter towards the live blade segment (15) to be measured under the constraints of elastic limit force, force detection, movement stroke and independent mechanical limit, and form a reference shape. During the process, the second blade segment positioning component (4) is allowed to move slightly along the length direction driven by the change in the projected length of the blade segment, and the peak force and maximum stroke are recorded; S6, the projected area and contour data of the reference measurement state are collected under the same measurement coordinates as in step S3; S7, after the reference measurement state is collected, the upper flexible flattening component (7) and the lower reference support component (5) are returned to their respective retraction positions and leave the blade envelope of the live blade segment (15) to be tested, so that the live blade segment (15) to be tested is restored to a state of no contact on both sides; S8, at one or more preset time points after release, the projected area, contour and features of the release measurement state are collected under the same measurement coordinates as in step S3. Point position data; S9, compare the projected area, contour, and feature point positions of the natural measurement state and the released measurement state to obtain the area recovery error, contour recovery error, and position slippage, and check the peak force, maximum stroke, and whether there are scratches, creases, indentations, tears, increased curling, or independent mechanical limit failures recorded in step S5; S10, only when the area recovery error, contour recovery error, position slippage, peak force, and maximum stroke do not exceed their respective corresponding thresholds and no abnormality as described in step S9 occurs, retain the reference measurement state area and contour data obtained in step S6; otherwise, do not retain the reference measurement state data and record the corresponding abnormality.

8. The method for measuring the area and contour of a live maize leaf segment in multiple states according to claim 7, characterized in that, In steps S3 and S8, the test living leaf segment (15) is confirmed to maintain a visible air gap with the upper flexible flattening component (7) and the lower reference support component (5) by side observation or image confirmation; in step S4, the lower reference support component (5) is first brought to the reference support position, and in step S5, the upper flexible flattening component (7) is lowered by limiting force; in step S7, the upper flexible flattening component (7) is first raised, and then the lower reference support component (5) is lowered; when a non-contact infrared temperature measurement module is used, the leaf temperature is collected in step S3 before any mechanical contact occurs.

9. The method for measuring the area and contour of a live maize leaf segment in multiple states according to claim 7, characterized in that, Let the projected area of ​​the natural measurement state be... After release The projected area at time is The first in the natural measurement state and the release measurement state The positions of the corresponding feature points are respectively and The contours of the natural measurement state and the release measurement state are respectively and Area recovery error is calculated according to Calculate the maximum position slip according to Calculate the contour recovery error according to Calculate; when If there are no scratches, creases, indentations, tears, increased curling, visible damage, or independent mechanical limit failure, the data of this reference measurement state shall be retained; otherwise, it shall not be retained and shall be recorded as a suspected mechanical disturbance.

10. The method for measuring the area and contour of a live maize leaf segment in multiple states according to claim 7, characterized in that, The preset time points for step S8 include one or more of 0 s, 10 s, 30 s, and 60 s after release; after the data in the reference measurement state meets the retention conditions, at least one of the cross-sectional curling index and the projection loss rate is calculated, wherein the projection width is in the natural measurement state. and reference measurement state projection width Calculate the cross-sectional curl index, the cross-sectional curl index according to... Calculate; projected area in natural measurement state Projected area of ​​reference measurement state Calculate the projection loss rate, the projection loss rate according to... calculate.

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