Watermelon internal quality distribution uniformity nondestructive testing device and method

Abstract

The invention provides a watermelon internal quality distribution uniformity nondestructive testing device and method, and is applied to the technical field of watermelon quality nondestructive testing, the device comprises: a three-dimensional multispectral acquisition module, which is used for carrying out photoelectric signal acquisition on a detected watermelon through a preset light source wavelength combination to obtain a transmission light signal; the signal acquisition control circuit is used for responding to the control signal and driving the three-dimensional multispectral acquisition module; the microprocessor is used for sending a control signal to the signal acquisition control circuit, receiving the transmission light signal transmitted by the three-dimensional multispectral acquisition module, and performing three-dimensional distribution inversion of the watermelon sugar degree and the watermelon hardness based on the transmission light signal to obtain a watermelon detection signal; the display module is used for receiving the watermelon detection signal transmitted by the microprocessor, generating a three-dimensional sugar degree and hardness distribution diagram corresponding to the detected watermelon based on the watermelon detection signal, and displaying the three-dimensional sugar degree and hardness distribution diagram; according to the invention, the accuracy and reliability of lossless watermelon quality evaluation can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of non-destructive detection of watermelon quality, and particularly to a non-destructive detection device and method for the uniformity of the internal quality distribution of watermelons. Background Art

[0002] During the growth of watermelons, the accumulation and distribution of sugars, and the formation of pulp hardness are interactively affected by various factors such as variety, growing conditions (such as soil type, water supply, light), and maturity, making the measurement of quality distribution extremely complex. The sugar content and hardness distribution patterns of different varieties of watermelons vary significantly, and changes in the growing environment can also cause uneven quality distribution, while picking at an inappropriate maturity will further exacerbate the inconsistency of quality.

[0003] Traditional detection methods require destructive sampling and manual inspection. The sugar content detection of watermelons mainly relies on the measurement of sugar content at a single location or the evaluation of the overall sugar content. For example, common sugar content measurement methods include using a refractometer to measure the sugar content of watermelon juice, or measuring the hardness of the pulp through a compression test. However, these methods have significant limitations. Measuring the sugar content at a single location is difficult to reflect the internal sugar content distribution of the entire watermelon, while the evaluation of the overall sugar content and hardness cannot reveal the specific internal distribution.

[0004] Therefore, it can be seen that the existing methods for detecting the internal quality of watermelons have the technical problem that they cannot comprehensively and accurately evaluate the quality of watermelons without damage. Summary of the Invention

[0005] The present invention provides a non-destructive detection device and method for the uniformity of the internal quality distribution of watermelons, so as to solve the defect that the existing methods for detecting the internal quality of watermelons cannot comprehensively and accurately evaluate the quality of watermelons without damage, and to improve the accuracy and reliability of watermelon quality evaluation.

[0006] The present invention provides a non-destructive detection device for the uniform distribution of the internal quality of watermelons, comprising: a three-dimensional multi-spectral acquisition module for collecting optoelectronic signals from the watermelon to be measured through a preset light source wavelength combination to obtain transmitted light signals; a signal acquisition control circuit communicatively connected to the three-dimensional multi-spectral acquisition module for driving the three-dimensional multi-spectral acquisition module in response to a control signal; a microprocessor communicatively connected to the signal acquisition control circuit and the three-dimensional multi-spectral acquisition module respectively for sending the control signal to the signal acquisition control circuit and receiving the transmitted light signals transmitted by the three-dimensional multi-spectral acquisition module, and performing three-dimensional distribution inversion of the watermelon sugar content and watermelon hardness based on the transmitted light signals to obtain watermelon detection signals; a display module communicatively connected to the microprocessor for receiving the watermelon detection signals transmitted by the microprocessor, generating a three-dimensional sugar content and hardness distribution map corresponding to the watermelon to be measured based on the watermelon detection signals, and displaying the three-dimensional sugar content and hardness distribution map; and a power supply module electrically connected to the signal acquisition control circuit, the microprocessor and the display module respectively, and powered by an AC 220V to DC 24V switching power supply.

[0007] According to a non-destructive detection device for the uniform distribution of the internal quality of watermelons provided by the present invention, the three-dimensional multi-spectral acquisition module comprises: an optoelectronic acquisition module, an electric opening and closing mechanism and a fruit tray; the optoelectronic acquisition module is installed on the electric opening and closing mechanism, the electric opening and closing mechanism is used to open or close the optoelectronic acquisition module, and the optoelectronic acquisition module is used to perform omnidirectional acquisition of the projection spectrum and reflection spectrum of the watermelon to be measured in a closed detection space; the fruit tray is installed at the middle position of the electric opening and closing mechanism and forms a cross base with the electric opening and closing mechanism.

[0008] A non-destructive detection device for the uniformity of the internal quality distribution of watermelons provided by the present invention, the photoelectric acquisition module includes: a multi-wavelength annular light source, which is composed of a plurality of multi-wavelength light-emitting diode lamp boards arranged in a ring. Each multi-wavelength light-emitting diode lamp board integrates light-emitting diodes of multiple wavelengths. Each wavelength of the light-emitting diodes is configured with multiple lamp beads. The multiple lamp beads are arranged in a preset row and column form, and the multiple lamp beads of each wavelength are independently controlled to be turned on and off; a photoelectric detector assembly, which includes a plurality of photoelectric detectors distributed along the latitude direction and a plurality of photoelectric detectors distributed along the longitude direction, and together form a transmission light signal acquisition array with a preset row and column number of points. The end of the photoelectric detector is equipped with a telescopic black rubber light-shielding sheath to fit the surface of the watermelon to be measured; a profiling micro darkroom, which is symmetrically divided into two half shells on the left and right. The side wall of the profiling micro darkroom is provided with a light source installation area and upper and lower photoelectric detector installation areas. The light source installation area is used to install the multi-wavelength annular light source, and the upper and lower photoelectric detector installation areas are used to install the photoelectric detector assembly; light-shielding partitions are arranged on both sides of the light source installation area to limit the irradiation angle to 0 degrees, and the upper and lower photoelectric detector installation areas are respectively arranged with photoelectric detector vacancies in a preset row and column number array.

[0009] A non-destructive detection device for the uniformity of the internal quality distribution of watermelons provided by the present invention, the photoelectric detector is a photomultiplier tube, and the telescopic black rubber light-shielding sheath is a bellows-like telescopic structure, which is used to adapt to the change of the surface distance between the photomultiplier tube and the watermelon to be measured.

[0010] A non-destructive detection device for the uniformity of the internal quality distribution of watermelons provided by the present invention, the profiling micro darkroom forms a closed detection space through the closure of the two half shells. The closed detection space is a complete hollow cylinder, which is used to shield the interference of ambient stray light.

[0011] A non-destructive detection device for the uniformity of the internal quality distribution of watermelons provided by the present invention, the electric opening and closing mechanism includes: a stepping motor and a screw table linear module. The screw table linear module includes a screw with a positive and negative thread structure. The screw is divided into a left half section and a right half section with a central axis as the boundary. The left half section is processed with a positive thread, and the right half section is processed with a negative thread; a first slider and a second slider are respectively arranged on the positive thread and the negative thread; the output shaft of the stepping motor is coaxially connected with the screw. When the screw rotates clockwise, it drives the first slider and the second slider to move towards each other to realize the closing action. When the screw rotates counterclockwise, it drives the two sliders to move away from each other to realize the opening action.

[0012] A non-destructive detection device for the uniformity of the internal quality distribution of watermelons provided by the present invention, the light source wavelength combination includes a sensitive band of 1000-1400nm and a reference band of 700-750nm for sugar content detection, and a high absorption band of 850-1000nm for water content detection.

[0013] The present invention also provides a non-destructive detection method for the uniformity of the internal quality distribution of watermelons, which includes the following steps: collecting optoelectronic signals from the watermelon to be measured through a preset light source wavelength combination to obtain transmitted light signals; performing three-dimensional distribution inversion of the watermelon sugar content and watermelon hardness based on the transmitted light signals to obtain watermelon detection signals; generating a three-dimensional sugar content and hardness distribution map corresponding to the watermelon to be measured based on the watermelon detection signals, and displaying the three-dimensional sugar content and hardness distribution map.

[0014] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the non-destructive detection method for the uniformity of the internal quality distribution of watermelons as described in any one of the above.

[0015] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the non-destructive detection method for the uniformity of the internal quality distribution of watermelons as described in any one of the above.

[0016] The present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the non-destructive detection method for the uniformity of the internal quality distribution of watermelons as described in any one of the above.

[0017] The non-destructive detection device and method for the uniformity of the internal quality distribution of watermelons provided by the present invention can efficiently obtain watermelon transmitted light signals through a three-dimensional multi-spectral acquisition module combined with a preset light source wavelength combination, and can capture the differences in the absorption and scattering characteristics of light by different tissues inside the watermelon; the signal acquisition control circuit ensures the synchronization and stability of optoelectronic signal acquisition; the microprocessor realizes the three-dimensional distribution inversion of sugar content and hardness based on the transmitted signal, improving the detection accuracy and efficiency; the display module intuitively presents the three-dimensional sugar content and hardness distribution map, facilitating the rapid judgment of quality uniformity; the power supply module adopts an AC-to-DC scheme to ensure the safe and reliable operation of the device, and overall realizes the non-destructive, rapid, and visual detection of the internal quality of watermelons. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the description of the embodiments or the prior art will be briefly introduced one by one below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 is the overall structural block diagram of the non-destructive detection device for the uniformity of the internal quality distribution of watermelons provided by the present invention.

[0020] Figure 2 It is a schematic structural diagram of the multi-wavelength separately controlled LED light board provided by the present invention.

[0021] Figure 3 It is a schematic structural diagram of the multi-wavelength annular light source provided by the present invention.

[0022] Figure 4 It is a schematic structural diagram of the profiling micro darkroom provided by the present invention.

[0023] Figure 5 It is a three-dimensional structural diagram of the photoelectric acquisition module provided by the present invention.

[0024] Figure 6 It is a schematic structural diagram of the photodetector and the light-shielding sheath provided by the present invention.

[0025] Figure 7 It is a structural diagram of the electric opening and closing mechanism provided by the present invention.

[0026] Figure 8 It is a schematic structural diagram of the fruit tray provided by the present invention.

[0027] Figure 9 It is the overall structure of the diffused light three-dimensional acquisition module provided by the present invention.

[0028] Figure 10 It is a schematic diagram of the basic method flow for detecting the sugar content and hardness distribution inside a watermelon provided by the present invention.

[0029] Figure 11 It is a schematic diagram of the application scenario of the internal quality distribution detector for watermelons provided by the present invention.

[0030] Figure 12 It is a schematic diagram of the closed state of the three-dimensional multi-spectral acquisition module provided by the present invention.

[0031] Figure 13 It is a schematic diagram of the open state of the three-dimensional multi-spectral acquisition module provided by the present invention.

[0032] Figure 14 It is a schematic diagram of the physical structure of the electronic device provided by the present invention. Specific Embodiments

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] Watermelon (Citrullus lanatus), as a globally favored fruit, is deeply loved by consumers for its sweet and juicy taste and rich nutrition. However, there are significant inhomogeneities in the internal quality of watermelons in terms of sugar content and hardness. In terms of the eating experience, the center part after cutting has a high sugar content and appropriate hardness, while the area near the peel has a low sugar content, hard pulp and may be sour, seriously affecting consumers' overall evaluation of watermelon quality. During the growth process of watermelons, the accumulation and distribution of sugars and the formation of pulp hardness are interactively affected by various factors such as variety, planting conditions (such as soil type, water supply, light), and maturity, making the measurement of quality distribution extremely complex. There are obvious differences in the sugar content and hardness distribution patterns among different watermelon varieties, changes in the planting environment can also lead to uneven quality distribution, and improper harvesting due to immaturity will further exacerbate the inconsistency of quality.

[0035] Traditional detection methods require destructive sampling and manual inspection. The sugar content detection of watermelons mainly relies on the sugar content measurement at a single location or the evaluation of the overall sugar content. For example, common sugar content measurement methods include using a refractometer to measure the sugar content (Brix value) of watermelon juice, or measuring the hardness of the pulp through a compression test. However, these methods have significant limitations. Measuring the sugar content at a single location is difficult to reflect the internal sugar content distribution of the entire watermelon, while the evaluation of the overall sugar content and hardness cannot reveal the specific internal distribution, resulting in the inability to comprehensively and accurately evaluate the quality of watermelons.

[0036] Current fruit sugar content measuring instruments on the market, such as near-infrared spectrometers that can be used for fruit testing, can measure the sugar content of the whole fruit. Desktop watermelon spectrometers use a cold light source combined with a soft rubber light-shielding structure and can be used for fruit sugar content detection, but they are all single-point reflection spectrometers and are only suitable for measuring the single-point sugar content of thin-skinned small fruits. The spectrometer is split into multiple points for collection through optical fibers, but the spectra collected at multiple points ultimately converge into the same spectrometer, and can only detect the average sugar content of the area covered by the probe. The high water content and porous tissue structure of watermelons make traditional electrochemical and optical detection methods easily interfered during application and difficult to achieve high-precision quality measurement. Secondly, the internal structure of watermelons is complex, containing a large amount of water and various cell tissues, which makes it difficult for existing imaging and sensing technologies to accurately distinguish the changes in sugar content and hardness in different regions.

[0037] In view of the inhomogeneity of the internal quality distribution (including sugar content and hardness) of watermelons and the multiple challenges faced during the detection process, developing a non-destructive detection method and device that can efficiently and accurately detect the internal quality distribution of watermelons has important practical significance and broad application prospects.

[0038] To solve the above problems, the present invention proposes a watermelon internal hardness detection system based on near-infrared spectroscopy (NIR) and diffuse optical tomography (DOT). Near-infrared spectroscopy has the advantages of being fast, non-destructive, and capable of penetrating relatively thick rinds, and is suitable for preliminary sugar content and hardness detection. However, when using NIR technology alone in watermelons with high moisture and complex tissue structures, the signals are easily absorbed and scattered, resulting in low detection accuracy. Diffuse optical tomography can generate three-dimensional optical images of the inside of the watermelon through multi-angle and multi-wavelength optical signal acquisition and reconstruction, providing more detailed and accurate internal structure information. Combining NIR and DOT can effectively overcome the limitations of single technologies and achieve high-precision and all-round detection of the sugar content and hardness distribution inside the watermelon. Specifically, NIR technology is used to quickly obtain the spectral information inside the watermelon and preliminarily evaluate the distribution of sugar content and hardness; DOT technology further generates detailed quality distribution images of the inside of the watermelon through complex optical model reconstruction. This combination not only improves the accuracy of detection but also can complete the hardness detection of a large number of watermelons in a relatively short time, meeting the requirements of modern agricultural production for efficient and accurate detection.

[0039] Figure 1 is the overall structural block diagram of the non-destructive detection device for the uniformity of the internal quality distribution of watermelons provided by the present invention, as Figure 1 shown, the device includes: 1. A three-dimensional multi-spectral acquisition module, which is used to collect optoelectronic signals from the watermelon to be measured through a preset light source wavelength combination to obtain transmitted light signals; 2. A signal acquisition control circuit, which is communicatively connected to the three-dimensional multi-spectral acquisition module in 1, and is used to drive the three-dimensional multi-spectral acquisition module in 1 in response to a control signal; 3. A microprocessor, which is communicatively connected to the signal acquisition control circuit in 2 and the three-dimensional multi-spectral acquisition module in 1 respectively, and is used to send a control signal to the signal acquisition control circuit in 2, receive the transmitted light signals transmitted by the three-dimensional multi-spectral acquisition module in 1, and perform three-dimensional distribution inversion of the watermelon sugar content and watermelon hardness based on the transmitted light signals to obtain watermelon detection signals; 4. A display module, which is communicatively connected to the microprocessor in 3, and is used to receive the watermelon detection signals transmitted by the microprocessor in 3, generate three-dimensional sugar content and hardness distribution maps corresponding to the watermelon to be measured based on the watermelon detection signals, and display the three-dimensional sugar content and hardness distribution maps; 5. A power supply module, which is electrically connected to the signal acquisition control circuit in 2, the microprocessor in 3, and the display module in 4 respectively, and is powered by an AC 220V to DC 24V switching power supply.

[0040] The implementation of diffuse optical tomography measurement for watermelon requires measuring the optical flow distribution at other points on the surface under multi-point excitation. Figure 1 Figure Figure 1 is the overall structural block diagram of the non-destructive detection device for the internal quality distribution uniformity of watermelon, which consists of five parts, namely 1 three-dimensional multi-spectral acquisition module, 2 acquisition control circuit, 3 microprocessor, 4 display module, and 5 power supply module.

[0041] Among them, the 1 three-dimensional multi-spectral acquisition module is responsible for collecting optoelectronic signals with the watermelon, and the 2 signal acquisition control circuit is responsible for receiving the signals from the 3 microprocessor and driving the 1 three-dimensional multi-spectral acquisition module to perform acquisition. The 5 power supply module uses an AC 220V to DC 24V switching power supply, and can also be externally connected to the robot power supply when the instrument is used as an end effector on the robot.

[0042] Through the embodiments of the present invention, by combining the three-dimensional multi-spectral acquisition module with a preset light source wavelength combination, the transmitted light signal of the watermelon can be efficiently obtained, and the differences in the absorption and scattering characteristics of light by different tissues inside the watermelon can be captured; the signal acquisition control circuit ensures the synchronization and stability of optoelectronic signal acquisition; the microprocessor realizes the three-dimensional distribution inversion of sugar content and hardness based on the transmitted signal, improving the detection accuracy and efficiency; the display module intuitively presents the three-dimensional sugar content and hardness distribution maps, facilitating the rapid judgment of quality uniformity; the power supply module adopts an AC-to-DC scheme to ensure the safe and reliable operation of the equipment, and overall realizes the non-destructive, fast, and visual detection of the internal quality of watermelon.

[0043] According to a non-destructive detection device for the internal quality distribution uniformity of watermelon provided by the present invention, the three-dimensional multi-spectral acquisition module includes: an optoelectronic acquisition module, an electric opening and closing mechanism, and a fruit tray. The optoelectronic acquisition module is installed on the electric opening and closing mechanism, and the electric opening and closing mechanism is used to open or close the optoelectronic acquisition module. The optoelectronic acquisition module is used to perform omnidirectional acquisition of the projection spectrum and reflection spectrum of the watermelon to be measured in a closed detection space. The fruit tray is installed at the middle position of the electric opening and closing mechanism, forming a cross base with the electric opening and closing mechanism.

[0044] The core component of the detector for the internal sugar content and hardness distribution of watermelon (i.e., the non-destructive detection device for the internal quality distribution uniformity of watermelon) is the three-dimensional multi-spectral acquisition module, which consists of three parts, namely an optoelectronic acquisition module, an electric opening and closing mechanism, and a fruit tray.

[0045] Through the embodiments of the present invention, the electric opening and closing mechanism drives the photoelectric acquisition module to dynamically close to form a closed detection space, effectively isolating the interference of ambient light; its adjustable opening and closing angle can adapt to watermelons of different sizes; the photoelectric acquisition module uses a multi-directional and multi-angle light source array and a high-sensitivity photoelectric sensor in the closed space to synchronously collect the optical scattering characteristics of the surface and inside of the watermelon. Combined with the cross-shaped base positioning structure of the fruit holder, the watermelon to be measured is kept stable and centered during the detection process, avoiding the deviation of optical signals caused by displacement or tilt, and ensuring the consistency and reliability of data acquisition.

[0046] A non-destructive detection device for the uniformity of the internal quality distribution of a watermelon provided by the present invention, the photoelectric acquisition module includes: A multi-wavelength ring light source, which is composed of a plurality of multi-wavelength light-emitting diode lamp boards arranged in a ring. Each multi-wavelength light-emitting diode lamp board integrates light-emitting diodes of multiple wavelengths. Each wavelength of light-emitting diodes is configured with multiple lamp beads. The multiple lamp beads are arranged in the form of a preset number of rows and columns. The multiple lamp beads of each wavelength are independently controlled to turn on and off; A photoelectric detector assembly, including a plurality of photoelectric detectors distributed along the latitude direction and a plurality of photoelectric detectors distributed along the longitude direction, forming a transmission light signal acquisition array with a preset number of rows and columns of points. The end of the photoelectric detector is equipped with a telescopic black rubber light-shielding sheath to fit the surface of the watermelon to be measured; A profiling micro darkroom, which is symmetrically divided into two half shells on the left and right. The side wall of the profiling micro darkroom is provided with a light source installation area and upper and lower photoelectric detector installation areas. The light source installation area is used to install the multi-wavelength ring light source, and the upper and lower photoelectric detector installation areas are used to install the photoelectric detector assembly; light-shielding partitions are arranged on both sides of the light source installation area to limit the irradiation angle to 0 degrees, and the upper and lower photoelectric detector installation areas are respectively arranged with photoelectric detector vacancies in a preset number of rows and columns array.

[0047] In the related art, when using the diffusion spectroscopy tomography technology to detect the internal quality of watermelons, high-resolution three-dimensional optical imaging is crucial for accurately reflecting the internal sugar content and hardness distribution, and is the key basis for quality evaluation. However, the internal structure of watermelons is complex, with a large amount of water and various cell tissues, making the propagation path of light in them changeable and difficult to analyze. The density, composition, and arrangement of different tissues are different, increasing the complexity of light propagation, resulting in the detection system being difficult to distinguish subtle structural and characteristic differences, and having extremely high requirements for the resolution and accuracy of the system.

[0048] In the embodiments of the present invention, referring to Figure 2 , Figure 2 is a schematic structural diagram of the multi-wavelength separately controlled LED lamp board provided by the present invention, where it includes: multiple lamp beads corresponding to wavelength 1, multiple lamp beads corresponding to wavelength 2, multiple lamp beads corresponding to wavelength 3, multiple lamp beads corresponding to wavelength 4, and multiple lamp beads corresponding to wavelength 5.

[0049] Figure 2 It is a multi-wavelength light-emitting diode (LED) ring light source. The basic unit of the ring light source is a multi-wavelength lamp board. Five wavelengths of LEDs are integrated on each lamp board, with three lamp beads for each wavelength, arranged in a 5×3 form. The on / off of each lamp bead of each wavelength can be independently controlled, and the wavelengths are preferably selected through the traditional watermelon sugar content spectral detection method. Eighteen lamp boards are installed on a profiling micro darkroom to form a ring light source. Reference Figure 3 , Figure 3 It is a structural schematic diagram of the multi-wavelength ring light source provided by the present invention.

[0050] As Figure 3 shown. When the light source works, it is turned on and off in sequence according to the wavelength on the same lamp board. After one lamp board is turned on and off, the next lamp board repeats the operation of the previous lamp board until all lamp boards complete one on / off operation. Multi-wavelength and multi-position light source illumination is realized.

[0051] It should be noted that both the traditional watermelon table type and the detection equipment are open, and the stray light entering the photoelectric sensor cannot be controlled, resulting in measurement errors and signal noise.

[0052] According to a non-destructive detection device for the uniformity of the internal quality distribution of watermelons provided by the present invention, the profiling micro darkroom is formed by closing two half shells to form a closed detection space. The closed detection space is a complete hollow cylinder, which is used to shield the interference of ambient stray light.

[0053] In the embodiment of the present invention, reference Figure 4 , Figure 4 It is a structural diagram of the profiling micro darkroom provided by the present invention.

[0054] Figure 4 is a profiling micro darkroom. The profiling micro darkroom has two functions. One is to serve as the installation base for the multi-wavelength ring light source and the photodetector, and the other is to shield the external ambient light to prevent stray light from entering the photodetector and affecting the detection result. The profiling micro darkroom is designed as an 18-sided columnar shell, symmetrically divided into two half shells on the left and right, and closed into a complete hollow cylinder during operation to enclose the watermelon. Upper photodetector installation areas, lower photodetector installation areas and light source installation areas are designed on the side walls of the half shells. Light-shielding partition plates are designed on both sides of the light source installation area to limit the light irradiation angle of the light source to 0 degrees, and 4×9 photodetector installation vacancy arrays are respectively designed in the upper and lower installation areas for installing photodetectors.

[0055] Through the embodiment of the present invention, the profiling light-shielding darkroom is designed to form a micro darkroom, which completely encloses the watermelon during operation, and can avoid the interference of ambient light.

[0056] Reference Figure 5 , Figure 5It is a three-dimensional structure diagram of the photoelectric acquisition module provided by the present invention, which includes: a light-shielding cover, a light acquisition field angle limiting rubber tube, a multi-wavelength LED combined light source, and a light source irradiation angle limiting plate.

[0057] If Figure 5 As shown, the multi-wavelength annular light source and the photoelectric detector are respectively installed in the light source installation area and the upper and lower photoelectric detector installation areas of the profiled micro darkroom, forming an overall two semi-open (three-dimensional) photoelectric signal acquisition module. 18 photoelectric detectors are distributed in each layer along the latitude direction, and 8 photoelectric detectors are distributed along the longitude direction, and a total of 18×8 points of transmitted light signals can be detected.

[0058] According to a non-destructive detection device for the uniformity of the internal quality distribution of watermelons provided by the present invention, the photoelectric detector is a photomultiplier tube, and the retractable black rubber light-shielding sheath is an accordion-shaped retractable structure for adapting to the change of the surface distance between the photomultiplier tube and the watermelon to be measured.

[0059] Reference Figure 6 , Figure 6 It is a structural schematic diagram of the photoelectric detector and the light-shielding sheath provided by the present invention.

[0060] Figure 6 As shown, the photoelectric detector and the retractable black rubber light-shielding sheath are shown. The photoelectric detector uses a photomultiplier tube, which has the advantages of a wide sensing range, high sensitivity, and low cost. A retractable accordion-shaped black rubber sheath is designed at the end of the photoelectric detector, which can adapt to the change of the distance between the photoelectric detector and the watermelon, always fit the surface of the watermelon, and prevent stray light from entering.

[0061] Through the embodiment of the present invention, a multi-angle acquisition scheme is adopted. The light signals are collected from multiple angles and directions, expanding the traditional single-point light intensity acquisition to three-dimensional space acquisition, and designing a three-dimensional array distribution of an all-round photoelectric detection sensor around the watermelon. The light at different angles carries different internal structure information. By comprehensively analyzing these signals, more comprehensive internal structure information can be obtained, effectively improving the imaging resolution and accuracy, and providing strong support for accurately presenting the distribution of sugar content and hardness inside the watermelon.

[0062] According to a non-destructive detection device for the uniformity of the internal quality distribution of watermelons provided by the present invention, an electric opening and closing mechanism includes: A stepping motor and a lead screw slide linear module. The lead screw slide linear module includes a lead screw with a positive and reverse thread structure. The left half of the lead screw is processed with a positive thread, and the right half is processed with a reverse thread; A first slider and a second slider are respectively and cooperatively arranged on the right-hand thread and the left-hand thread; the output shaft of the stepping motor is coaxially connected to the lead screw. When the lead screw rotates clockwise, it drives the first slider and the second slider to move towards each other to achieve the closing action. When the lead screw rotates counterclockwise, it drives the two sliders to move away from each other to achieve the opening action.

[0063] Reference Figure 7 , Figure 7 is the structural diagram of the electric opening and closing mechanism provided by the present invention.

[0064] The electric opening and closing mechanism is responsible for driving the opening and closing of the optical detection device ( Figure 7 as shown), and consists of two parts, namely a lead screw and slide linear module and a stepping motor. The lead screw and slide linear module transmits motion through a lead screw. In the traditional right-hand lead screw or left-hand lead screw, the present invention combines the two and designs them as a right-hand and left-hand lead screw. The left half of the lead screw is a right-hand thread, and the right half is a left-hand thread. This design enables the two sliders to move towards the middle when the lead screw rotates clockwise and move towards both sides when the lead screw rotates counterclockwise, synchronously achieving the opening and closing actions. The unilateral stroke of the slide linear module is 100 mm, the diameter of the lead screw is 16 mm, and the lead is 5 mm, which can ensure that the slider has sufficient opening and opening and closing speed. The stepping motor is connected to the linear module through a coupling and is used to drive the slide linear module. The stepping motor uses a 57 stepping motor with a torque of 1.3 Nm.

[0065] Reference Figure 8 , Figure 8 is the structural schematic diagram of the fruit tray provided by the present invention.

[0066] The structure of the fruit tray is as Figure 8 shown. A depression with a certain depth is designed at the top of the fruit tray to make the watermelon more stable when placed, and a door-shaped groove is opened at the bottom for cross-mounted cooperation with the electric opening and closing mechanism.

[0067] Reference Figure 9 , Figure 9 is the overall structure of the diffuse light three-dimensional acquisition module provided by the present invention, including: an LED combined lamp board, a light-shielding cover, a photomultiplier tube, a stepping motor, a right-hand and left-hand linear slide, and a fruit tray.

[0068] The three parts of the photoelectric acquisition module, the electric opening and closing module, and the fruit tray are combined to form a complete three-dimensional multi-spectral acquisition module for watermelons. The structural diagram is as Figure 9 shown. Two photoelectric acquisition modules are installed on the sliders of the electric opening and closing module, and the fruit tray is placed in the middle position of the slide to form a stable cross base with the electric slide.

[0069] A non-destructive detection device for the uniform distribution of the internal quality of watermelons provided by the present invention, the light source wavelength combination includes a sensitive band of 1000-1400 nm for sugar content detection and a reference band of 700-750 nm, and a high absorption band of 850-1000 nm for water content detection.

[0070] In the related art, the differences in the volume of watermelons will affect the spectral shape and intensity, and further affect the prediction accuracy of the internal quality of watermelons.

[0071] In the process of predicting the internal quality of watermelons using spectral technology, the significant differences in the volume of watermelons will directly affect the spectral shape and intensity. From the perspective of optical principles, the internal material distribution and light propagation path of watermelons with different volumes are different. When light penetrates a watermelon, for a larger watermelon compared to a smaller one, the light travels a longer distance inside and encounters more scattering and absorbing substances. This results in differences in the shape and intensity of the spectra reflected or transmitted by watermelons of different volumes, and thus seriously affects the prediction accuracy of the internal quality of watermelons.

[0072] In the embodiments of the present invention, a high absorption band for components such as water and sugar at 850-1000 nm is selected, combined with a band less affected by volume at 700-750 nm. Sensitivity band and reference band combination: Select a band sensitive to the sugar content of the pulp (such as 1000–1400 nm) and combine it with a band relatively unaffected by volume to obtain the light source wavelength combination. By calculating the ratio or difference of these bands, the influence of volume differences can be effectively eliminated.

[0073] Specifically, it includes: data acquisition and wavelength selection. For example, collect spectral data of more than 100 watermelon samples with different volumes, covering different volume ranges. Select wavelengths highly correlated with sugar content as quality-sensitive wavelengths and combine them with bands highly correlated with water absorption.

[0074] Through the embodiments of the present invention, different wavelength combinations are selected to eliminate the systematic error caused by volume differences. By selecting wavelengths with a stable relationship between the signal intensity and volume when light passes through watermelons with different internal sugar contents, as a base reference to calibrate the changing optical path. Specifically, the combination of the sensitivity band corresponding to the soluble solids determining the quality of watermelons and the reference band of the water base highly correlated with the volume of watermelons can achieve the elimination or significant reduction of the systematic error caused by the volume differences of watermelons. Utilizing the high response characteristics of the sensitivity band based on the sugar content of watermelons, and at the same time relying on the stable characteristics of the reference band of watermelon water, through the comparison of the two, the interference factors caused by volume differences are effectively eliminated, thereby significantly improving the accuracy of predicting the internal quality of watermelons.

[0075] Reference Figure 10 ,Figure 10 It is a schematic diagram of the basic method flow for detecting the sugar content and hardness distribution inside a watermelon provided by the present invention. It includes: a multi-wavelength visible-near infrared light source (emitting near-infrared light of different wavelengths to penetrate the fruit), a photodetector matrix column (receiving the transmitted light signal inside the fruit), a data acquisition and control system (signal acquisition, preprocessing, and control of the light source), a reconstruction algorithm and signal processing (reconstruction and processing based on the diffusion method), and data visualization and output (generating a three-dimensional sugar content distribution image).

[0076] The basic method flow for detecting the sugar content and hardness distribution inside a watermelon is as Figure 10 shown. The multi-wavelength visible-near infrared light source sequentially emits near-infrared light of different wavelengths to penetrate the watermelon. The photodetector array distributed around the watermelon epidermis receives the transmitted light signal inside the watermelon. Signal acquisition, preprocessing, and control of the light source are performed in the microprocessor, and the sugar content and quality are reconstructed based on the watermelon tissue diffusion equation. Finally, the result data is visualized to generate a three-dimensional sugar content distribution image.

[0077] In related technologies, for thin-skinned fruits such as apples and pears, their fruit skins are relatively thin, and in the spectral characteristics of the entire fruit, the influence generated by the fruit skin can usually be ignored. However, for watermelons as thick-skinned fruits, the situation is completely different. When using only the transmission spectrum to detect the internal quality of a watermelon, since the light needs to penetrate the entire watermelon, including the fruit skin with strong spectral absorption, the transmission spectrum signal will be significantly interfered by the fruit skin and cannot accurately reflect the true situation inside the watermelon. The reflection spectrum mainly reflects the surface of the watermelon, that is, the characteristics of the fruit skin, and it is difficult to obtain sufficient internal information.

[0078] Using only the transmission spectrum will be affected by the fruit skin, while the reflection spectrum more reflects the characteristics of the fruit skin. By combining the transmission spectrum and the reflection spectrum, the present invention can obtain more comprehensive internal and external information of the watermelon, thereby helping to correct the influence of the fruit skin. The photoelectric signals collected by the photodetectors on each lamp board are reflection signals, and the photoelectric signals collected by the photodetectors opposite each other along the diameter direction are transmission signals. After the sequential on and off of 18 lamp boards is completed, the photoelectric acquisition system obtains 18 groups of reflection spectra and transmission spectra. Using the ratio of the reflection spectrum and the transmission spectrum as the input value of the prediction model can reduce the influence of the fruit skin in the transmission spectrum. The calculation formula for the ratio of the reflection spectrum to the transmission spectrum is: where represents the reflection spectrum signal intensity, which reflects the reflection ability of the watermelon fruit skin surface to light of different wavelengths and related optical characteristics; Represents the intensity of the transmission spectral signal, which contains the information carried by the light after penetrating the internal tissues of the watermelon, but is interfered by factors such as peel absorption. By calculating the ratio of the two, the influence brought by the peel absorption characteristics can be eliminated or weakened to a certain extent, enabling the subsequent watermelon internal quality prediction model based on this ratio to more accurately reflect the true internal quality status of the watermelon, such as key indicators like sugar content and hardness distribution.

[0079] Through the embodiments of the present invention, a scheme of jointly using transmission spectrum and reflection spectrum is proposed to eliminate the influence of the peel on the prediction of the internal quality of the watermelon. By simultaneously collecting the transmission spectrum and the reflection spectrum, more comprehensive internal and external information of the watermelon can be obtained. The transmission spectrum carries the information after the light penetrates the internal tissues of the watermelon, while the reflection spectrum reflects the characteristics of the watermelon surface including the peel. By combining the two and using data analysis algorithms, the influence law of the peel on the spectrum can be analyzed, and the interference components of the peel can be effectively removed from the overall spectral information, thereby correcting the influence of the peel and providing a reliable data basis for accurately predicting the internal quality of the watermelon.

[0080] In the related art, NIR and DOT technologies respectively provide spectral information and three-dimensional imaging data. How to effectively fuse these two types of data to comprehensively reflect the quality distribution of sugar content and hardness inside the watermelon is an important technical challenge.

[0081] The three-dimensional distribution inversion model of watermelon sugar content is constructed based on the theory of diffuse optical tomography, including three main parts: the photon transport model (forward problem), image reconstruction technology (inverse problem), and diffuse optical measurement system.

[0082] DOT image reconstruction is an inverse problem: Its formal definition is: Given the spatio-temporal distribution of the light source on the tissue surface and the spatio-temporal distribution of the corresponding transmitted light measurement, based on a specific photon transport model, solve the three-dimensional distribution of the optical parameters inside the tissue. The task of DOT imaging is to simultaneously reconstruct the distribution of all optical parameters in the tissue domain, and in applications, it is often assumed that one or two parameter distributions (usually the refractive index) are known constants to simplify the solution of the problem, that is, usually only the absorption coefficient and the reduced scattering coefficient are reconstructed. If the random noise effect is not considered, the image reconstruction can be represented by a non-linear least squares optimization problem, such as the Newton-Raphson method, a commonly used image reconstruction technology based on the linearization of the forward model.

[0083] The implementation of DOT requires measuring the light flux distribution (broadly regarded as projection) at other points on the surface under multi-point excitation (broadly regarded as multi-angle scanning), and optical projection and reception can be carried out using optical fibers in direct contact or spatial light. Currently, there are mainly three modes for the diffuse optical measurement system: time-resolved measurement mode, continuous light measurement mode, and frequency-domain measurement mode.

[0084] A forward model based on the diffusion equation is used to simulate the propagation of light inside a watermelon. A watermelon is usually a tissue with a complex geometry and a non-uniform distribution of optical parameters, and the analytical solution of the diffusion equation can only be obtained under the conditions of a tissue domain with a regular geometry and a uniform distribution of optical parameters. Therefore, in the present invention, the finite element method of the diffusion equation is used for numerical solution. The forward model can be personalized according to the size and shape of the watermelon to improve the accuracy of the reconstruction results.

[0085] Main steps of the diffusion equation: The radiance , scattering phase function and source term mentioned in the radiative transfer theory are expanded using spherical harmonics. The three-term time-domain form is expanded as where, represents the radiance, indicating the light energy distribution at position , direction , time ; represents the nth-order internal mode, represents the order, is the spherical harmonic function; is the expansion coefficient, represents the scattering phase function, describing the probability distribution of photons scattered from direction to direction ; represents the Legendre expansion coefficient, represents the complex conjugate of the spherical harmonic function, represents the source term, represents the spherical harmonic expansion coefficient of the source, reflecting the directivity of the source, represents the normalization factor, ensuring the orthogonality of the spherical harmonic functions.

[0086] By performing a low-order expansion of the radiative equation, the time-domain diffusion equation can be expressed as: where the diffusion coefficient is: Reduced scattering coefficient: where, represents the photon energy density, represents the diffusion coefficient, represents the absorption coefficient, is the reduced scattering coefficient, is the anisotropy factor, is the speed of light, is the isotropic light source term.

[0087] When measuring watermelon tissue, based on the time and spatial distributions of the incident light (light source term) and the transmitted light (detection term), by repeatedly solving the forward problem of light propagation, the calculated value is made to infinitely approach the measured value, so as to inversely calculate the distributions of optical parameters such as the absorption coefficient and scattering coefficient inside the tissue.

[0088] After data acquisition is sequentially carried out under 5-wavelength light sources, the spatio-temporal distribution of the light source on the surface of the watermelon tissue body and the corresponding spatio-temporal distribution of the measured transmitted light are obtained. Based on the photon transport model, the three-dimensional distributions of the optical parameters corresponding to 5 different wavelengths of light in the tissue are solved. The absorption and scattering coefficients are inversely calculated using the non-linear iterative method (Levenberg-Marquardt method), and the sugar content distribution at different depths of the watermelon is calculated according to the traditional sugar content and hardness regression model. To avoid the introduction of errors due to noise amplification and data ill-posedness, the Tikhonov regularization method is adopted to ensure the smoothness and physical meaning of the reconstruction of the sugar content distribution.

[0089] Through the embodiments of the present invention, an optical diffusion model of watermelon tissue is proposed, a data fusion algorithm integrating NIR spectral data and DOT imaging data is developed to extract comprehensive features. The three-dimensional sugar content and quality are inversely calculated from the collected data.

[0090] The uniformity of the sugar content and hardness distributions of the internal quality of the watermelon is classified according to the coefficient of variation. The calculation formulas for the coefficients of variation of the sugar content and hardness are: where is the standard deviation of the sugar content or hardness at each point; is the average value of the sugar content or hardness at each point.

[0091] The calculation formula for the average value is: [[ID=3l]]where N is the total number of data points of the sugar content or hardness, is the sugar content value or hardness value at the i-th point.

[0092] The calculation formula for the standard deviation is: where is the sugar content value or hardness value at the i-th point, is the average value of the sugar content or hardness.

[0093] The uniformity of the sugar content and hardness distributions is respectively divided into 3 grades. Grade 1 has the highest uniformity, Grade 2 has the second highest uniformity, and Grade 3 has the worst uniformity. The classification criteria are as follows: Considering that the sugar content uniformity and hardness uniformity of watermelons are not unified, the present invention comprehensively considers the sugar content uniformity and hardness uniformity, establishes an overall uniformity index for the internal quality of watermelons, which is divided into 5 levels in total. Among them, the overall uniformity of level 1 is the highest, and the overall uniformity of level 5 is the lowest. The grading standard is shown in Table 1.

[0094] Table 1 Grading standard for the overall uniformity of the internal quality of watermelons

[0095] The following describes an example of the non-destructive detection device for the uniform distribution of the internal quality of watermelons provided by the present invention in an actual application scenario. Specifically, it includes the following steps: Step 1, Watermelon placement: Place the watermelon on the detection platform, and adjust the distances between the light source and the detector and the watermelon surface according to the size of the watermelon to ensure the detection effect.

[0096] Step 2, Multi-wavelength three-dimensional distribution light intensity detection: After starting the system, the multi-wavelength near-infrared light source emits light in sequence, and the detector array synchronously collects the light signals passing through the watermelon at different angles and depths to obtain detection data.

[0097] Step 3, Data preprocessing: The collected light signals enter the data acquisition module, and real-time preprocessing operations such as noise elimination and signal amplification are performed to improve the data quality.

[0098] Step 4, Reconstructing the sugar content and hardness distribution: The preprocessed signals are input into the reconstruction algorithm. Through the forward model and inverse problem solution, the absorption and scattering coefficient distributions at different depths of the watermelon are reconstructed, and then the specific sugar content distribution is inferred based on the light absorption characteristics.

[0099] Step 5, Visualization and output: Generate a three-dimensional sugar content and hardness distribution map of the inside of the watermelon and display it in real time. At the same time, the system generates a quality report to intuitively present the detection results.

[0100] Reference Figure 11 , Figure 11 is a schematic diagram of the application scenario of the detector for the internal quality distribution of watermelons provided by the present invention. Among them, it includes: (A) Application scenario 1: Desktop detection equipment (B) Application scenario 2: End of the in-situ detection robot for watermelons on the branch The detection device of the present invention mainly has two application scenarios. First, Application scenario 1: It can be used as an independent desktop device, suitable for detecting the quality of watermelons in fixed places such as laboratories and warehouses (as shown in Figure 11 (A)). Second, Application scenario 2: The device base is installed on the robotic arm as an end effector, which can realize in-situ detection during the growth process of watermelons in the orchard and provide real-time data (as shown in Figure 11 (B)).

[0101] Reference Figure 12 , Figure 12 is a schematic diagram of the closed state of the three-dimensional multi-spectral acquisition module provided by the present invention.

[0102] Reference Figure 13 , Figure 13 is a schematic diagram of the open state of the three-dimensional multi-spectral acquisition module provided by the present invention.

[0103] Through the embodiments of the present invention, non-destructive detection of watermelons can be carried out before picking to ensure that the sugar content and hardness of each watermelon meet the preset standards. The detection results can be displayed in real time to help farmers screen out high-quality watermelons, improving market competitiveness and economic benefits. By analyzing the sugar content and hardness distribution of different varieties of watermelons, excellent genes with uniform sugar content distribution, high sweetness and moderate hardness can be identified, which can be used to guide the improvement of watermelon varieties and cultivation, and accelerate the cultivation of new high-quality watermelon varieties.

[0104] Through the above embodiments of the present invention, at least the following technical effects are achieved: Realize the measurement of the three-dimensional spatial distribution of watermelon sugar content. The present invention utilizes the scattering and absorption characteristics of near-infrared light in watermelons, the multi-wavelength absorption characteristics of near-infrared light and the optimized detector arrangement, and combines the diffusion optical tomography reconstruction algorithm to achieve non-destructive detection of the quality distribution such as sugar content and hardness at different depths of watermelons.

[0105] The light source structure is reasonably designed. The present invention arranges the multi-wavelength LED light source in a ring, while evenly illuminating the watermelon, the heat generated by the light source is dispersed to avoid scalding the watermelon skin. The ring light source is controlled separately and opened and closed alternately according to the wavelength, realizing the acquisition of optical diffusion information at multiple wavelengths by a set of equipment.

[0106] Effective stray light control. The present invention effectively avoids the interference of external ambient light by designing an openable and closable profiling micro-darkroom. Inside the micro-darkroom, a compressible black rubber light-shielding tube is designed at the end of each photodetector, which can adapt to different distances from the photodetector to the watermelon skin and prevent light crosstalk near the photodetector.

[0107] Diverse application scenarios. The present invention designs the photoelectric acquisition module to be openable and closable left and right, and uses a positive and negative thread slider linear mechanism for electric control opening and closing, so that the instrument can not only be used as a tabletop device, but also can be installed on a robotic arm as an end effector to perform in-situ detection on the watermelon on the branch, meeting different agricultural production requirements.

[0108] The following describes the non-destructive detection method for the uniformity of the internal quality distribution of watermelons provided by the present invention. The non-destructive detection method for the uniformity of the internal quality distribution of watermelons described below can be mutually corresponding and referred to the non-destructive detection device for the uniformity of the internal quality distribution of watermelons described above.

[0109] Collect optoelectronic signals of the watermelon to be measured through a preset combination of light source wavelengths to obtain transmitted light signals; Invert the three-dimensional distribution of the watermelon sugar content and watermelon hardness based on the transmitted light signals to obtain watermelon detection signals; Generate a three-dimensional sugar content and hardness distribution map corresponding to the watermelon to be measured based on the watermelon detection signals, and display the three-dimensional sugar content and hardness distribution map.

[0110] Specifically, the non-destructive detection method for the uniformity of the internal quality distribution of watermelons provided by the present invention can implement all the method steps implemented by the non-destructive detection device embodiment for the uniformity of the internal quality distribution of watermelons, and can achieve the same technical effects. Therefore, the same parts and beneficial effects as those in the method embodiment will not be specifically described herein.

[0111] Figure 14 is a schematic physical structure diagram of an electronic device provided by the present invention. As Figure 14 shown, the electronic device may include: a processor 1410, a communication interface 1420, a memory 1430, and a communication bus 1440. Among them, the processor 1410, the communication interface 1420, and the memory 1430 communicate with each other through the communication bus 1440. The processor 1410 can call the logical instructions in the memory 1430 to execute the non-destructive detection method for the uniformity of the internal quality distribution of watermelons. The method includes: collecting optoelectronic signals of the watermelon to be measured through a preset combination of light source wavelengths to obtain transmitted light signals; inverting the three-dimensional distribution of the watermelon sugar content and watermelon hardness based on the transmitted light signals to obtain watermelon detection signals; generating a three-dimensional sugar content and hardness distribution map corresponding to the watermelon to be measured based on the watermelon detection signals, and displaying the three-dimensional sugar content and hardness distribution map.

[0112] In addition, when the logical instructions in the above-mentioned memory 1430 are implemented in the form of software function units and sold or used as an independent product, they can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs, Read-Only Memories), random access memories (RAMs, Random Access Memories), magnetic disks, or optical discs that can store program codes.

[0113] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the non-destructive detection method for the uniformity of the internal quality distribution of watermelons provided by the above-mentioned various methods. The method includes: collecting optoelectronic signals of the watermelon to be measured through a preset light source wavelength combination to obtain transmitted light signals; performing three-dimensional distribution inversion of watermelon sugar content and watermelon hardness based on the transmitted light signals to obtain watermelon detection signals; generating a three-dimensional sugar content and hardness distribution map corresponding to the watermelon to be measured based on the watermelon detection signals, and displaying the three-dimensional sugar content and hardness distribution map.

[0114] In another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it realizes the non-destructive detection method for the uniformity of the internal quality distribution of watermelons provided by the above-mentioned various methods. The method includes: collecting optoelectronic signals of the watermelon to be measured through a preset light source wavelength combination to obtain transmitted light signals; performing three-dimensional distribution inversion of watermelon sugar content and watermelon hardness based on the transmitted light signals to obtain watermelon detection signals; generating a three-dimensional sugar content and hardness distribution map corresponding to the watermelon to be measured based on the watermelon detection signals, and displaying the three-dimensional sugar content and hardness distribution map.

[0115] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative labor.

[0116] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disc, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0117] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A non-destructive testing device for the uniformity of the internal quality distribution of watermelons, characterized in that, Comprising: A three-dimensional multispectral acquisition module, configured to collect optoelectronic signals of the watermelon to be measured through a preset light source wavelength combination, and obtain transmitted light signals; A signal acquisition control circuit, communicatively connected to the three-dimensional multispectral acquisition module, and configured to drive the three-dimensional multispectral acquisition module in response to a control signal; A microprocessor, communicatively connected to the signal acquisition control circuit and the three-dimensional multispectral acquisition module respectively, configured to send the control signal to the signal acquisition control circuit, receive the transmitted light signals transmitted by the three-dimensional multispectral acquisition module, and perform three-dimensional distribution inversion of the watermelon sugar content and watermelon hardness based on the transmitted light signals to obtain watermelon detection signals; A display module, communicatively connected to the microprocessor, configured to receive the watermelon detection signals transmitted by the microprocessor, generate a three-dimensional sugar content and hardness distribution map corresponding to the watermelon to be measured based on the watermelon detection signals, and display the three-dimensional sugar content and hardness distribution map; A power supply module, electrically connected to the signal acquisition control circuit, the microprocessor, and the display module respectively, and powered by an AC 220V to DC 24V switching power supply.

2. The non-destructive detection device for the uniform distribution of the internal quality of a watermelon according to claim 1, characterized in that The three-dimensional multispectral acquisition module includes: an optoelectronic acquisition module, an electric opening and closing mechanism, and a fruit tray; The optoelectronic acquisition module is installed on the electric opening and closing mechanism, the electric opening and closing mechanism is configured to open or close the optoelectronic acquisition module, and the optoelectronic acquisition module is configured to perform omnidirectional acquisition of the projection spectrum and reflection spectrum of the watermelon to be measured in a closed detection space; The fruit tray is installed at the middle position of the electric opening and closing mechanism, and forms a cross base with the electric opening and closing mechanism.

3. The non-destructive detection device for the uniform distribution of the internal quality of watermelons according to claim 2, wherein, The optoelectronic acquisition module includes: A multi-wavelength annular light source, which is formed by annularly arranging a plurality of multi-wavelength light-emitting diode lamp boards. Each multi-wavelength light-emitting diode lamp board integrates light-emitting diodes of multiple wavelengths. Each wavelength of light-emitting diode is configured with multiple lamp beads. The multiple lamp beads are arranged in a preset row and column form, and the multiple lamp beads of each wavelength are independently controlled to turn on and off; An optoelectronic detector assembly, including a plurality of optoelectronic detectors distributed along the latitude direction and a plurality of optoelectronic detectors distributed along the longitude direction, together forming a transmitted light signal acquisition array with a preset row and column number of points. The end of the optoelectronic detector is equipped with a telescopic black rubber light-shielding sheath to fit the surface of the watermelon to be measured; A profiling micro darkroom, symmetrically divided into two half shells on the left and right. The side wall of the profiling micro darkroom is provided with a light source installation area and upper and lower optoelectronic detector installation areas. The light source installation area is used to install the multi-wavelength annular light source, and the upper and lower optoelectronic detector installation areas are used to install the optoelectronic detector assembly; light-shielding partition plates are arranged on both sides of the light source installation area to limit the irradiation angle to 0 degrees, and the upper and lower optoelectronic detector installation areas are respectively arranged with optoelectronic detector vacancies in a preset row and column number array.

4. The non-destructive detection device for the uniform distribution of the internal quality of watermelons according to claim 3, wherein, The optoelectronic detector is a photomultiplier tube, and the telescopic black rubber light-shielding sheath is a bellows-like telescopic structure, configured to adapt to the change in the surface spacing between the photomultiplier tube and the watermelon to be measured.

5. The non-destructive detection device for the uniform distribution of the internal quality of a watermelon according to claim 3, characterized in that The profiling micro darkroom is formed by closing the two half shells to form a closed detection space, which is a complete hollow cylinder for shielding environmental stray light interference.

6. The non-destructive detection device for the uniform distribution of the internal quality of a watermelon according to claim 2, wherein The electric opening and closing mechanism includes: A stepper motor and a lead screw slide linear module. The lead screw slide linear module includes a lead screw with a positive and negative thread structure. The lead screw is divided by the central axis. The left half is machined with a positive thread, and the right half is machined with a negative thread; A first slider and a second slider are respectively arranged on the positive thread and the negative thread; the output shaft of the stepper motor is coaxially connected to the lead screw. When the lead screw rotates clockwise, it drives the first slider and the second slider to move towards each other to realize the closing action. When the lead screw rotates counterclockwise, it drives the two sliders to move away from each other to realize the opening action.

7. The non-destructive detection device for the uniform distribution of the internal quality of watermelons according to claim 1, wherein, The light source wavelength combination includes a sensitive band of 1000 - 1400nm and a reference band of 700 - 750nm for sugar content detection, and a high absorption band of 850 - 1000nm for moisture detection.

8. A non-destructive testing method for the uniformity of the internal quality distribution of watermelons, characterized in that, It includes: Collecting photoelectric signals from the watermelon to be measured through the preset light source wavelength combination to obtain transmitted light signals; Inverting the three-dimensional distribution of the sugar content and hardness of the watermelon based on the transmitted light signals to obtain watermelon detection signals; Generating a three-dimensional sugar content and hardness distribution map corresponding to the watermelon to be measured based on the watermelon detection signals, and displaying the three-dimensional sugar content and hardness distribution map.

9. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the non-destructive detection method for the uniformity of the internal quality distribution of the watermelon as described in claim 8.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the non-destructive detection method for the uniformity of the internal quality distribution of the watermelon as described in claim 8.

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