A portable nondestructive testing device for internal quality of fresh fruit

Abstract

The present application relates to the field of fresh fruit detection, and particularly relates to a portable fresh fruit internal quality nondestructive testing device, which comprises a shell and a controller, the shell is fixedly connected with an extension shaft, the side of the extension shaft away from the shell is provided with a main probe, the main probe comprises a light source and a spectrum sensor, the light source and the spectrum sensor are electrically connected with the controller, the side of the extension shaft close to the main probe is provided with a sliding ring and a light shield for shielding external light; the sliding ring is provided with a opening component for opening the light shield. The extension shaft is further provided with a moving mechanism for driving the sliding ring to slide and a transmission mechanism for driving the main probe to rotate; the light shield is further provided with a contact component for contacting the outer wall of the fresh fruit. The present application can establish a stable darkroom in the working environment, realize multi-angle scanning, and reduce the interference of external light, so as to improve the accuracy of fresh fruit internal quality detection.

Description

Technical Field

[0001] This invention relates to the field of fresh fruit testing, specifically to a portable non-destructive testing device for the internal quality of fresh fruit. Background Technology

[0002] With consumers' increasing demands for fresh fruit quality and the acceleration of agricultural modernization, the internal quality of fresh fruit (such as sugar content, acidity, firmness, dry matter content, and internal browning) has become a key factor affecting its commercial value, storage performance, and market competitiveness. Traditional methods for testing the quality of fresh fruit mainly rely on destructive sampling, such as cutting open the fruit and using a refractometer, titration, or texture analyzer for measurement. These methods not only cause fruit loss and cannot be used for full inspection of commercial fruit, but also suffer from low efficiency and high subjectivity, making it difficult to meet the needs of modern fruit industry for rapid, accurate, and non-destructive testing in harvesting decisions, grading and sales, cold chain logistics, and quality traceability.

[0003] In recent years, non-destructive testing technologies based on optical principles (such as visible-near-infrared spectroscopy, hyperspectral imaging, or Raman spectroscopy) have gradually become important means of assessing the internal quality of fresh fruit due to their advantages such as non-contact, rapid response, and quantifiability. However, existing equipment is mostly large benchtop instruments, which typically suffer from problems such as large size, high cost, and complex operation. Furthermore, they have high requirements for the testing environment (such as lighting and stability), making them unsuitable for practical applications in orchards, fields, sorting lines, or wholesale markets. Although some portable devices exist, they generally suffer from severe ambient light interference, poor adhesion to the fruit surface, and limited testing areas. When faced with fruits of different shapes, sizes, and surface curvatures, they struggle to establish stable optical testing conditions, resulting in limited testing accuracy and reliability.

[0004] Therefore, this invention proposes a portable non-destructive testing device for the internal quality of fresh fruit to improve the accuracy of internal quality testing of fresh fruit. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a portable non-destructive testing device for the internal quality of fresh fruit. Through a mechanical linkage design, the device simultaneously completes the unfolding of the light shield, the contact component engagement, and the rotation of the main probe during the movement of the sliding ring. This enables the establishment of a stable darkroom in the working environment, achieves multi-angle scanning, and reduces external light interference, thereby improving the accuracy of fresh fruit internal quality testing.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A portable non-destructive testing device for the internal quality of fresh fruit includes a housing and a controller. An extension shaft is fixedly connected to the housing. A main probe is provided on the side of the extension shaft away from the housing. The main probe includes a light source and a spectral sensor. Both the light source and the spectral sensor are electrically connected to the controller. A sliding ring and a light shield for blocking external light are provided on the side of the extension shaft near the main probe. An opening component for opening the light shield is provided on the sliding ring.

[0007] The extension shaft is also equipped with a moving mechanism for driving the sliding ring to slide and a transmission mechanism for driving the main probe to rotate; the light shield is also equipped with a contact component for contacting the outer wall of the fresh fruit.

[0008] When the moving mechanism drives the sliding ring to slide, the sliding ring unfolds the light shield through the expanding component; at the same time, the main probe is driven to rotate through the transmission mechanism; and the contact component is used to adhere to the surface of the fresh fruit to form a detection dark chamber.

[0009] The technical principles of the above solution are as follows:

[0010] A sliding ring is driven by a moving mechanism, and during this sliding process, a linkage expansion component unfolds the light-shielding cover, which then adheres to the surface of the fresh fruit through a contact component, forming a sealed dark chamber to reduce ambient light interference. Simultaneously, the displacement of the sliding ring is converted into rotational motion via a transmission mechanism, driving the main probe to rotate and enabling multi-angle spectral scanning of the fresh fruit. A light source emits light of a specific wavelength that penetrates the fruit pulp. A spectral sensor collects the absorption and reflection characteristic signals of the internal components of the fresh fruit (such as sugar content, acidity, or ripeness) in response to this light. The optical signals are converted into electrical signals and transmitted to the controller for analysis, ultimately outputting the internal quality detection results of the fresh fruit.

[0011] The above approach has the following beneficial effects:

[0012] 1. This solution employs a mechanical linkage design, simultaneously completing the deployment of the light shield, the engagement of the contact components, and the rotation of the main probe during the movement of the sliding ring. The sealed dark chamber formed by the light shield and the contact components blocks ambient light, preventing stray light from interfering with the spectral signal; the rotation of the main probe ensures that the light source and spectral sensor can cover a wide detection area. This integrated environmental control design eliminates the need for additional auxiliary equipment during the detection process, enabling the acquisition of relatively stable detection data even in outdoor environments, thus improving the reliability and repeatability of the detection results.

[0013] 2. This solution integrates multiple preparatory actions into a single continuous mechanical motion. Operators only need to activate the controller to move the sliding ring closer to the fresh fruit, and the device will complete the darkroom setup and main probe adjustment. This one-button operation simplifies the testing process. Furthermore, the device employs an integrated structure, combining the controller, moving mechanism, and transmission mechanism within the housing. With an extension shaft design, the overall size is compact and lightweight, making it easy to carry to various locations such as orchards and markets for on-site testing, thus meeting portable testing needs.

[0014] 3. This solution uses a transmission mechanism to drive the main probe to rotate, expanding the detection range of the device and adapting to the detection of various fresh fruits. The expandable design of the light shield and the flexible fit structure of the contact components can accommodate fresh fruits of different sizes, ensuring the darkroom is sealed. Simultaneously, the controller has built-in detection models for multiple types of fresh fruits, allowing for the detection of various fruits by switching parameters without changing the probe or equipment, reducing detection costs and providing a more flexible detection solution for multiple stages of agricultural production, fresh fruit procurement, and market circulation.

[0015] Furthermore, the expansion assembly includes several expansion arms circumferentially hinged to the outer wall of the extension shaft, and a light shield is fixedly connected to the side of the expansion arm away from the extension shaft; several connecting rods are circumferentially hinged to the outer wall of the sliding ring, and the ends of the connecting rods away from the sliding ring are all hinged to the expansion arms.

[0016] Beneficial effects: The axial movement of the sliding ring drives the connecting rod to push and pull the expansion arm, realizing the automatic expansion and contraction of the light shield. The action is reliable and the response is rapid. The expansion arm is evenly distributed around the circumference, so that the light shield is subjected to balanced force, ensuring a tight fit and good sealing performance. It effectively blocks external light, provides a stable darkroom environment for spectral detection, and improves detection accuracy and repeatability.

[0017] Furthermore, the moving mechanism includes a lead screw rotatably fitted to the inner wall of the extension shaft, a nut seat threaded onto the lead screw, the nut seat being fixedly connected to the inner wall of the sliding ring; the nut seat slidingly fitted to the side wall of the extension shaft; and a drive assembly for rotating the lead screw is provided inside the housing.

[0018] Beneficial effects: The drive assembly rotates the lead screw, causing the nut seat to slide smoothly along the extension shaft, thereby controlling the axial displacement of the sliding ring; the structure is compact, the transmission is stable, and the response is sensitive, ensuring that the actions of the light shield opening, probe rotation, and fruit surface contact are synchronized and coordinated, providing a foundation for the formation of a reliable darkroom and the realization of multi-angle scanning.

[0019] Furthermore, the drive assembly includes a drive component, which is electrically connected to the controller and fixedly connected to the inner wall of the housing; the output shaft of the drive component is coaxially and fixedly connected to the lead screw.

[0020] Beneficial effects: The drive assembly electrically connects the drive unit to the controller and drives the lead screw through a coaxial fixing method. It has a simple structure, high transmission efficiency, and fast response speed. The controller can uniformly schedule and adjust the movement stroke and speed of the sliding ring to ensure that the light blocking, bonding and scanning actions are coordinated and consistent, thereby improving the automation level of the device.

[0021] Furthermore, the transmission mechanism includes a gear and an internal gear ring. The gear is coaxially and fixedly connected to the end of the lead screw away from the driving component. The gear meshes with the internal gear ring, and the internal gear ring is fixedly connected to the main probe.

[0022] Beneficial effects: The rotation of the lead screw synchronously drives the gear to rotate, and the meshing of the gear with the internal gear ring drives the main probe to rotate circumferentially, realizing multi-directional scanning of the light source and spectral sensor during the detection process; the structure is compact and the transmission is reliable, requiring no additional power source, effectively utilizing the kinetic energy of the moving mechanism, and improving integration and detection comprehensiveness.

[0023] Furthermore, the contact assembly includes an adhesive layer fixedly connected to the inner wall of the light shield; a transmission cylinder is fixedly connected to the inner wall of the extension shaft, a piston plate is slidably fitted to the inner wall of the transmission cylinder, a transmission rod is fixedly connected to the piston plate, and the end of the transmission rod away from the piston plate is fixedly connected to the outer wall of the nut seat; a transmission pipe is connected to the side of the transmission cylinder away from the transmission rod, and the end of the transmission pipe away from the transmission cylinder is connected to the interior of the adhesive layer.

[0024] Beneficial effects: The axial movement of the nut seat drives the transmission rod to push the piston plate, so that the fluid in the transmission cylinder is injected into the bonding layer through the transmission pipe, causing it to expand and flexibly adhere to the surface of the fresh fruit; no additional drive is required, and the displacement of the moving mechanism is cleverly used to achieve sealing, ensuring that the light shield is in close contact with the fruit surface, effectively blocking external light, and improving the stability of the darkroom and the reliability of detection.

[0025] Furthermore, the main probe is equipped with a flexible layer, and a displacement sensor is installed inside the flexible layer. The displacement sensor is used to obtain the displacement information of the flexible layer, and the controller calls the preset calibration model corresponding to the fresh fruit to be tested based on the displacement information.

[0026] Beneficial effects: The displacement sensor in the flexible layer senses the contact state and deformation of the main probe with the surface of the fresh fruit in real time. Based on this, the controller identifies the curvature characteristics of the fresh fruit and calls the corresponding preset correction model to dynamically compensate the spectral data, reducing the detection deviation caused by causal differences or changes in contact pressure.

[0027] Furthermore, the controller also has a built-in calibration program, which includes the following steps:

[0028] Acquire displacement information transmitted by the displacement sensor;

[0029] Determine whether the displacement has entered the preset detection range;

[0030] If so, the light source and spectral sensor will be triggered to work and collect spectral data at the current displacement.

[0031] Based on the displacement and a preset correction model, the spectral data is compensated in real time to obtain calibrated spectral data;

[0032] Calculate the internal quality parameters of fresh fruit based on the calibrated spectral data.

[0033] Beneficial effects: Real-time detection timing is determined by displacement, and spectral acquisition is triggered only within the effective contact range to avoid invalid or interfering data; the spectrum is compensated by combining displacement information with a preset correction model to reduce signal drift caused by causal factors and differences in contact state, thereby improving the accuracy of detection results and cross-fruit species applicability.

[0034] Furthermore, a pressure sensor is fixedly connected to the outer wall of the flexible layer, and the controller is also used to perform the following operations:

[0035] When the flexible layer comes into contact with the surface of the fresh fruit, the contact pressure data is obtained through a pressure sensor;

[0036] The control mechanism continues to drive the flexible layer to contact the surface of the fresh fruit until the pressure data fed back by the pressure sensor reaches the preset pressure threshold.

[0037] When the preset pressure threshold is reached, the main probe is activated to rotate and scan circumferentially via the transmission mechanism; and the light source and spectral sensor are activated to collect data.

[0038] Beneficial effects: The pressure sensor monitors the contact pressure between the flexible layer and the fresh fruit in real time, and the controller controls the advancement endpoint of the moving mechanism accordingly, ensuring that each test is carried out under consistent and appropriate pressure; avoiding light leakage due to insufficient contact or damage to the fruit surface due to excessive pressure, so as to better evaluate the internal quality of the fresh fruit.

[0039] Furthermore, the flexible layer is also connected to a connecting pipe, the end of which is away from the flexible layer is connected to the interior of the bonding layer, and a solenoid valve is also installed inside the connecting pipe.

[0040] When the pressure data fed back by the pressure sensor reaches the pressure threshold, the solenoid valve is activated, and the fluid medium is transferred into the bonding layer through the solenoid valve.

[0041] Beneficial effects: By controlling the injection of fluid medium into the bonding layer through the solenoid valve when the contact pressure reaches the threshold, the bonding layer expands and seals under suitable contact conditions, further enhancing the tightness of the bond between the light shield and the fruit surface, and improving the stability of the detection environment and the accuracy of spectral data. Attached Figure Description

[0042] Figure 1This is an isometric view of the portable non-destructive testing device for the internal quality of fresh fruit according to the present invention.

[0043] Figure 2 For the present invention Figure 1 The top sectional view in the image.

[0044] Figure 3 For the present invention Figure 1 Axonometric view of the centrally supported component.

[0045] Figure 4 For the present invention Figure 2 Enlarged view of part A in the middle.

[0046] Figure 5 For the present invention Figure 4 Axonometric drawing of the transmission mechanism.

[0047] The reference numerals in the accompanying drawings include: 1. Housing; 2. Extension shaft; 3. Main probe; 4. Sliding ring; 5. Light shield; 6. Spreading arm; 7. Connecting rod; 8. Lead screw; 9. Drive component; 10. Gear; 11. Internal gear ring; 12. Adhesive layer; 13. Transmission cylinder; 14. Piston plate; 15. Transmission rod; 16. Flexible layer. Detailed Implementation

[0048] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0050] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0051] The following detailed description illustrates the specific implementation method:

[0052] Example 1:

[0053] As attached Figures 1-5 As shown: A portable non-destructive testing device for the internal quality of fresh fruit includes a housing 1 and a controller. An extension shaft 2 is bolted to the housing 1. A main probe 3 is provided on the side of the extension shaft 2 away from the housing 1. The main probe 3 includes a light source and a spectral sensor. Both the light source and the spectral sensor are electrically connected to the controller. A sliding ring 4 and a light shield 5 for blocking external light are provided on the side of the extension shaft 2 near the main probe 3. An opening component for opening the light shield 5 is provided on the sliding ring 4.

[0054] The extension shaft 2 is also equipped with a moving mechanism for driving the sliding ring 4 to slide and a transmission mechanism for driving the main probe 3 to rotate; the light shield 5 is also equipped with a contact component for contacting the outer wall of the fresh fruit.

[0055] When the moving mechanism drives the sliding ring 4 to slide, the sliding ring 4 unfolds the light shield 5 through the expansion component; at the same time, the main probe 3 is driven to rotate through the transmission mechanism; and the contact component is used to adhere to the surface of the fresh fruit to form a detection dark chamber.

[0056] Combination Figure 2 and Figure 3 As shown, the expansion assembly includes several expansion arms 6 circumferentially hinged to the outer wall of the extension shaft 2, and the light shield 5 is fixedly bonded to the side of the expansion arm 6 away from the extension shaft 2; several connecting rods 7 are circumferentially hinged to the outer wall of the sliding ring 4, and the end of the connecting rod 7 away from the sliding ring 4 is hinged to the expansion arm 6.

[0057] Combination Figure 4 As shown, the moving mechanism includes a lead screw 8 rotatably fitted to the inner wall of the extension shaft 2, a nut seat threaded onto the lead screw 8, and the nut seat is fixedly connected to the inner wall of the sliding ring 4 with screws; the nut seat is slidably fitted to the side wall of the extension shaft 2. In this embodiment, the nut seat is embedded in the side wall of the extension shaft 2, so that the nut seat maintains a linear motion trajectory; the housing 1 is provided with a drive assembly for driving the lead screw 8 to rotate.

[0058] The drive assembly includes a drive component 9, which is a servo motor in this embodiment; the drive component 9 is electrically connected to the controller, and the drive component 9 is bolted to the inner wall of the housing 1; the output shaft of the drive component 9 is coaxial with the lead screw 8 and fixedly connected by a coupling.

[0059] Combination Figure 5 As shown, the transmission mechanism includes a gear 10 and an internal gear ring 11. The gear 10 is coaxially fixed to the end of the lead screw 8 away from the drive member 9. The gear 10 meshes with the internal gear ring 11, and the internal gear ring 11 is fixedly connected to the main probe 3 with a screw.

[0060] The contact assembly includes an adhesive layer 12 fixedly bonded to the inner wall of the light shield 5; a transmission cylinder 13 is fixedly connected to the inner wall of the extension shaft 2 by screws, a piston plate 14 is slidably fitted to the inner wall of the transmission cylinder 13, a transmission rod 15 is fixedly connected to the piston plate 14 by screws, and the end of the transmission rod 15 away from the piston plate 14 is fixedly connected to the outer wall of the nut seat by screws; a transmission tube is connected to the side of the transmission cylinder 13 away from the transmission rod 15, and the end of the transmission tube away from the transmission cylinder 13 is connected to the interior of the adhesive layer 12.

[0061] The specific implementation process is as follows: When internal quality testing of fresh fruit is required, the operator holds the device and aligns the front end of the extension shaft 2 with the surface of the fruit to be tested; the drive assembly is activated via the controller, and the drive component 9 (servo motor) begins to work, driving the lead screw 8 to rotate. As the lead screw 8 rotates, the nut seat that is threaded with it moves linearly along the sliding track on the inner wall of the extension shaft 2; the movement of the nut seat generates a coordinated action:

[0062] First, the nut seat pushes the piston plate 14 to move within the transmission cylinder 13 via the transmission rod 15. Simultaneously, the sliding ring 4, fixed to the nut seat, moves synchronously. The sliding ring 4, via the circumferentially hinged connecting rod 7, pushes each of the expansion arms 6 to unfold outward around its hinge point on the extension shaft 2. The expansion arms 6 drive the flexible light-shielding cover 5 fixed thereon to unfold synchronously, forming a gradually expanding bowl-shaped light-shielding structure. Figure 3 For example, when the sliding ring 4 moves to the right, the connecting rod 7 gradually pushes open the spreading arm 6.

[0063] When the lead screw 8 rotates, the gear 10 at its end rotates synchronously, driving the internal gear ring 11, which meshes with it, to rotate. Since the internal gear ring 11 is connected to the main probe 3, the rotation of the lead screw 8, through the engagement of the gear 10 and the internal gear ring 11, synchronously drives the main probe 3 to rotate slowly around its axis. As the assembly consisting of the spreading arm 6 and the light shield 5 approaches the fresh fruit, the soft and elastic bonding layer 12 adheres to the surface of the fruit. Simultaneously, the main probe 3 continuously fine-tunes its position relative to the surface of the fruit during rotation.

[0064] When the light shield 5 is unfolded, the bonding layer 12 at its edge first contacts the surface of the fresh fruit. During this close contact, the nut seat pushes the transmission rod 15 and piston plate 14 to move within the transmission cylinder 13, forcing the gas inside the transmission cylinder 13 into the bonding layer 12 through the transmission pipe. This causes the bonding layer 12 to expand and adhere tightly to the surface of the fresh fruit, further enhancing the sealing effect and ensuring that external light is effectively blocked, forming a darkroom for detection, in which the main probe 3 is located. In this embodiment, the larger the fresh fruit, the larger the expansion range of the spreading arm 6, and the tighter the bonding layer 12. However, it will not exceed the maximum expansion limit of the bonding layer 12. This expansion method matches the stroke of the spreading arm 6 and is determined according to the size of the fresh fruit.

[0065] When the controller determines through a preset program that the contact pressure and darkroom formation have reached the detection state, it triggers the main probe 3 to emit near-infrared light of a specific wavelength. The rotating main probe 3 then scans and illuminates a ring-shaped area on the surface of the fresh fruit, rather than illuminating a single point. The reflected light is received by the spectral sensor. Because the darkroom environment blocks stray light and the main probe 3 rotates to scan a wider area, the signal-to-noise ratio of the acquired spectral signal is significantly improved, making it more representative.

[0066] After the test is completed, the controller controls the drive component 9 to reverse, causing the lead screw 8 to rotate in the opposite direction; the nut seat returns to its original position, which in turn moves the sliding ring 4, pulling the expansion arm 6 to retract via the connecting rod 7, and the light shield 5 folds back to its original position; the piston plate 14 resets, and the gas flows back. The reverse rotation of the lead screw 8 drives the main probe 3 to rotate back to its initial angle via the gear ring mechanism of the gear 10; the device returns to its initial state, ready for the next test.

[0067] This embodiment achieves a series of complex actions simultaneously, including unfolding / retracting the light shield 5, establishing / releasing the seal of the detection dark chamber, rotating and scanning / resetting the main probe 3, and sealing / releasing, all through the forward and reverse rotation of the drive component 9. This simplifies the operation process and improves detection efficiency. The design of the flexible light shield 5 and the bonding layer 12 allows the device to adapt to fresh fruits of different sizes and shapes (such as apples or plums) and provides cushioning upon contact, preventing mechanical damage to the fruit's skin.

[0068] Example 2:

[0069] The difference from Embodiment 1 is that the main probe 3 is also provided with a flexible layer 16, and a displacement sensor is also provided in the flexible layer 16. The displacement sensor is used to obtain the displacement information of the flexible layer 16, and the controller calls the preset correction model corresponding to the fresh fruit to be tested based on the displacement information.

[0070] The specific implementation process is as follows: Before the test begins, the operator brings the main probe 3 of the device close to the surface of the fresh fruit to be tested. The flexible layer 16 first contacts the outer wall of the fresh fruit and deforms. At this time, the displacement sensor built into the flexible layer 16 detects the amount of compression in real time and transmits the displacement information to the controller.

[0071] After receiving the displacement data, the controller first determines whether the displacement falls within the preset valid detection range. Once the displacement enters the valid range, the controller identifies the approximate type or curvature characteristics of the current fruit based on the value (for example, a small displacement may correspond to an apple with a large curvature, while a large displacement may correspond to a plum or kiwi with a small curvature).

[0072] Subsequently, the controller invokes a preset calibration model corresponding to the displacement range. In this embodiment, the model is based on the spectral-quality parameter mapping relationship trained on a large number of similar fresh fruit samples, and has been optimized for compensation under different contact conditions. Under the guidance of the calibration model, the subsequently acquired raw spectral data will be corrected to reduce the impact of optical path changes caused by contact depth, fruit shape differences, or local deformation on the detection results.

[0073] Example 3:

[0074] The difference from Embodiment 2 is that the controller also has a built-in calibration program, which includes the following steps:

[0075] Acquire displacement information transmitted by the displacement sensor;

[0076] Determine whether the displacement has entered the preset detection range;

[0077] If so, the light source and spectral sensor will be triggered to work and collect spectral data at the current displacement.

[0078] Based on the displacement and a preset correction model, the spectral data is compensated in real time to obtain calibrated spectral data;

[0079] Calculate the internal quality parameters of fresh fruit based on the calibrated spectral data.

[0080] The specific implementation process is as follows: When the operator brings the device close to the fresh fruit to be tested and starts the detection, the flexible layer 16 comes into contact with the fruit surface and undergoes compression deformation. At this time, the displacement sensor monitors the deformation of the flexible layer 16 in real time and transmits the displacement information to the controller.

[0081] The controller first receives the displacement data and compares it with an internally preset effective detection range. This range is determined through extensive experimental calibration and ensures the formation of an optical path between the light source, the fruit pulp, and the sensor. If the current displacement has not yet entered this range (e.g., the probe is not making sufficient contact or is being excessively pressed in), the controller remains in standby mode and does not initiate optical acquisition.

[0082] Once the displacement enters the preset detection range, the controller triggers the calibration procedure: synchronously starts the light source to emit light of a specific wavelength (such as visible-near infrared light), and instructs the spectral sensor to start collecting the reflected spectral signal after scattering / absorption by the pulp tissue, thereby obtaining the raw spectral data.

[0083] At the same time, the controller, in conjunction with the current displacement value, retrieves a pre-set correction model (such as optical path correction coefficient or baseline drift compensation parameter for different degrees of compression) from the storage unit to dynamically compensate the original spectral data, eliminate signal deviations caused by contact pressure or fruit shape differences, and generate calibrated reliable spectral data.

[0084] Finally, based on the calibration spectrum, the controller calculates key internal quality parameters of the fresh fruit, such as soluble solids content (sugar content), titratable acidity, firmness, or maturity index, using built-in chemometric algorithms (such as PLS, SVR, or neural network models), and displays the results on the screen in real time or transmits them to an external terminal, completing the non-destructive quality testing process.

[0085] Example 4:

[0086] The difference from Embodiment 3 is that a pressure sensor is also fixedly bonded to the outer wall of the flexible layer 16, and the controller is also used to perform the following operations:

[0087] When the flexible layer 16 comes into contact with the surface of the fresh fruit, the contact pressure data is obtained by the pressure sensor;

[0088] The control mechanism continues to drive the flexible layer 16 to contact the surface of the fresh fruit until the pressure data fed back by the pressure sensor reaches the preset pressure threshold.

[0089] When the preset pressure threshold is reached, the main probe 3 is activated to rotate and scan circumferentially via the transmission mechanism; and the light source and spectral sensor are activated to collect data.

[0090] The specific implementation process is as follows: When the detection operation begins, the user brings the front end of the device close to the fresh fruit to be tested. When the flexible layer 16 first contacts the outer wall of the fresh fruit, the pressure sensor fixedly attached to its outer wall immediately senses the contact and begins to output real-time pressure data to the controller.

[0091] The controller continuously receives the pressure signal and compares it with the internally preset pressure threshold. This threshold is determined based on the characteristics of the fresh fruit skin (such as hardness and elasticity) and the optical detection contact conditions. It can ensure that the light shield 5 forms an effective seal with the fruit surface to isolate ambient light, and can also avoid excessive squeezing that could cause damage or deformation to the fruit surface.

[0092] At this stage, the controller does not immediately initiate optical acquisition, but continues to control the operation of the drive unit 9 (servo motor), causing the lead screw 8 to slowly move the nut seat and sliding ring 4 until the pressure value fed back by the pressure sensor stabilizes and reaches the preset threshold. At this point, it is determined that an ideal detection contact state has been established.

[0093] Once the pressure reaches the target, the controller simultaneously issues multiple commands: on the one hand, the main probe 3 is started to rotate circumferentially at a constant speed around its optical axis through the transmission mechanism (composed of gear 10 and internal gear ring 11) to achieve multi-angle scanning; on the other hand, the light source is triggered to emit a beam of light of a specific wavelength, and the spectral sensor is started to synchronously collect the reflected spectral signal after being acted upon by the pulp tissue.

[0094] Example 5:

[0095] The difference from Embodiment 4 is that the flexible layer 16 is also connected to a connecting pipe, and the end of the connecting pipe away from the flexible layer 16 is connected to the interior of the bonding layer 12. A solenoid valve is also provided inside the connecting pipe.

[0096] When the pressure data fed back by the pressure sensor reaches the pressure threshold, the solenoid valve is activated to transfer the fluid medium into the bonding layer 12; in this embodiment, the fluid medium is gas.

[0097] The specific implementation process is as follows: During the detection process, the flexible layer 16 first comes into contact with the surface of the fresh fruit. The pressure sensor integrated on its outer wall monitors the contact pressure in real time and transmits the data to the controller. The controller continuously determines whether the current pressure has reached the preset pressure threshold; this threshold represents the optimal contact state for forming an effective optical seal without damaging the fruit surface.

[0098] Before the pressure reaches the target level, the solenoid valve remains closed, and the bonding layer 12 is in a contracted or semi-bonded state to prevent premature filling that could affect positioning accuracy or cause the light shield 5 to shift. Once the pressure data from the pressure sensor stabilizes and reaches the preset threshold, the controller immediately issues a command to activate the solenoid valve in the connecting pipe.

[0099] After the solenoid valve is opened, the fluid medium stored inside the flexible layer 16 flows into the bonding layer 12 through the connecting pipe, causing it to expand locally and tightly wrap around the surface contour of the fresh fruit. Since the main probe 3 is now in the ideal contact position, the expansion of the bonding layer 12 further enhances the seal between the light shield 5 and the fruit surface, further blocking external stray light and forming a stable detection dark chamber. At the same time, the controller synchronously triggers the light source, spectral sensor, and transmission mechanism to begin circumferential scanning and spectral data acquisition, improving the device's adaptability and detection consistency under different fruit shapes and surface conditions.

[0100] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A portable non-destructive testing device for the internal quality of fresh fruit, comprising a housing (1) and a controller, wherein an extension shaft (2) is fixedly connected to the housing (1), and a main probe (3) is provided on the side of the extension shaft (2) away from the housing (1), the main probe (3) comprising a light source and a spectral sensor, both of which are electrically connected to the controller, characterized in that, The extension shaft (2) is provided with a sliding ring (4) and a light shield (5) for blocking external light on the side near the main probe (3); the sliding ring (4) is provided with a support assembly for opening the light shield (5); The extension shaft (2) is also provided with a moving mechanism for driving the sliding ring (4) to slide and a transmission mechanism for driving the main probe (3) to rotate; the light shield (5) is also provided with a contact component for contacting the outer wall of the fresh fruit. When the moving mechanism drives the sliding ring (4) to slide, the sliding ring (4) unfolds the light shield (5) through the expansion component; at the same time, the main probe (3) is driven to rotate through the transmission mechanism; and the contact component is used to adhere to the surface of the fresh fruit to form a detection dark chamber.

2. The portable non-destructive testing device for the internal quality of fresh fruit according to claim 1, characterized in that, The expansion assembly includes several expansion arms (6) circumferentially hinged to the outer wall of the extension shaft (2), and a light shield (5) is fixedly connected to the side of the expansion arm (6) away from the extension shaft (2); several connecting rods (7) are circumferentially hinged to the outer wall of the sliding ring (4), and the end of the connecting rod (7) away from the sliding ring (4) is hinged to the expansion arm (6).

3. The portable non-destructive testing device for the internal quality of fresh fruit according to claim 2, characterized in that, The moving mechanism includes a lead screw (8) that is rotatably fitted to the inner wall of the extension shaft (2), a nut seat that is threaded onto the lead screw (8), and the nut seat that is fixedly connected to the inner wall of the sliding ring (4); the nut seat that is slidably fitted to the side wall of the extension shaft (2); and a drive assembly for driving the lead screw (8) to rotate is provided inside the housing (1).

4. The portable non-destructive testing device for the internal quality of fresh fruit according to claim 3, characterized in that, The drive assembly includes a drive component (9), which is electrically connected to the controller and is fixedly connected to the inner wall of the housing (1); the output shaft of the drive component (9) is coaxially fixedly connected to the lead screw (8).

5. The portable non-destructive testing device for the internal quality of fresh fruit according to claim 4, characterized in that, The transmission mechanism includes a gear (10) and an internal gear ring (11). The gear (10) is coaxially fixedly connected to the end of the lead screw (8) away from the drive member (9). The gear (10) meshes with the internal gear ring (11), and the internal gear ring (11) is fixedly connected to the main probe (3).

6. The portable non-destructive testing device for the internal quality of fresh fruit according to claim 5, characterized in that, The contact assembly includes an adhesive layer (12) fixedly connected to the inner wall of the light shield (5); a transmission cylinder (13) is fixedly connected to the inner wall of the extension shaft (2), a piston plate (14) is slidably fitted to the inner wall of the transmission cylinder (13), a transmission rod (15) is fixedly connected to the piston plate (14), and the end of the transmission rod (15) away from the piston plate (14) is fixedly connected to the outer wall of the nut seat; a transmission pipe is connected to the side of the transmission cylinder (13) away from the transmission rod (15), and the end of the transmission pipe away from the transmission cylinder (13) is connected to the interior of the adhesive layer (12).

7. The portable non-destructive testing device for the internal quality of fresh fruit according to claim 6, characterized in that, The main probe (3) is also provided with a flexible layer (16), and a displacement sensor is also provided inside the flexible layer (16). The displacement sensor is used to obtain the displacement information of the flexible layer (16). The controller calls the preset correction model corresponding to the fresh fruit to be tested based on the displacement information.

8. The portable non-destructive testing device for the internal quality of fresh fruit according to claim 7, characterized in that, The controller has a built-in calibration program, which includes the following steps: Obtain the displacement information transmitted by the displacement sensor; Determine whether the displacement has entered the preset detection range; If so, the light source and spectral sensor will be triggered to work and collect spectral data at the current displacement. Based on the displacement and a preset correction model, the spectral data is compensated in real time to obtain calibrated spectral data; Calculate the internal quality parameters of fresh fruit based on the calibrated spectral data.

9. The portable non-destructive testing device for the internal quality of fresh fruit according to claim 8, characterized in that, A pressure sensor is also fixedly connected to the outer wall of the flexible layer (16), and the controller is also used to perform the following operations: When the flexible layer (16) comes into contact with the surface of the fresh fruit, the contact pressure data is obtained by the pressure sensor; The control mechanism continues to drive the flexible layer (16) to contact the surface of the fresh fruit until the pressure data fed back by the pressure sensor reaches the preset pressure threshold. When the preset pressure threshold is reached, the main probe (3) is activated to rotate and scan in the circumferential direction through the transmission mechanism; and the light source and spectral sensor are activated to collect data.

10. The portable non-destructive testing device for the internal quality of fresh fruit according to claim 9, characterized in that, The flexible layer (16) is also connected to a connecting pipe. The end of the connecting pipe away from the flexible layer (16) is connected to the interior of the bonding layer (12). A solenoid valve is also provided inside the connecting pipe. When the pressure data fed back by the pressure sensor reaches the pressure threshold, the solenoid valve is activated to transfer the fluid medium into the bonding layer (12).

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