High-quality tomato lossless sorting equipment based on electrical characteristic parameter measurement
By detecting the electrical characteristic parameters of tomatoes in an alternating electric field, and using electrode plates and an electrical characteristic parameter detector to analyze the complex impedance and complex permittivity of tomatoes, the inaccuracy and instability of tomato maturity detection in existing technologies are solved, and efficient and non-destructive tomato sorting and grading are achieved.
Patent Information
- Application Number
- CN202522194834.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-17
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2035-10-17
AI Technical Summary
In existing technologies, tomato ripeness detection relies on human sensory recognition, which is highly subjective and prone to misjudgment. Near-infrared spectroscopy and machine vision methods are difficult to accurately reflect the internal quality of tomatoes, while the tapping acoustic method is easily affected by environmental noise, resulting in unstable and inaccurate test results.
By detecting the changes in the electrical characteristic parameters of tomatoes in an alternating electric field, the complex impedance and complex permittivity of tomatoes are analyzed using electrode plates and an electrical characteristic parameter detector, enabling non-destructive testing of the ripeness and internal quality of tomatoes. Adaptive detection components and sorting equipment are then used for sorting.
This equipment enables precise sorting of tomatoes, allowing for accurate detection of tomato ripeness and internal quality. It features a simple structure, convenient operation, avoids damage to tomatoes, and improves detection speed and economic efficiency.
Smart Images
Figure CN223616280U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of fruit sorting equipment, specifically relating to a high-quality non-destructive sorting device for tomatoes based on the measurement of electrical characteristic parameters. Background Technology
[0002] Currently, the assessment of tomato ripeness and quality differences relies primarily on human sensory evaluation, which is highly subjective and prone to misjudgment. Non-destructive testing instruments for tomato ripeness can objectively measure ripeness differences and internal quality, meeting the testing needs of consumers, buyers, processing enterprises, and market regulators. Commonly used non-destructive testing technologies for fruit ripeness both domestically and internationally include: Near-infrared spectroscopy: This method experimentally determines the characteristic wavelengths of the fruit and analyzes its absorption spectrum to predict indicators such as sugar content and acidity. However, near-infrared light has limited penetration depth, making it difficult to reflect the overall uniformity of ripeness in tomatoes, and its measurement accuracy is affected by the internal structure of the peel and flesh. Machine vision: This method images tomatoes in the visible / near-infrared band and uses image processing technology to judge ripeness based on appearance indicators such as color, size, shape, and surface defects. This method mainly reflects surface information and has limited ability to detect internal quality; furthermore, high-precision systems are costly. The percussion acoustic method / sound vibration method: by exciting (e.g., tapping or hitting) tomatoes and receiving their vibration response signals, the spectral characteristics (such as resonant frequency) are analyzed to assess fruit firmness (related to maturity). This method is relatively simple to operate and has a low cost, but it is easily affected by environmental noise, operation methods, fruit size and shape, etc., which affect the stability and accuracy of the test results.
[0003] Therefore, developing a non-destructive sorting device for high and low quality tomatoes that is accurate in detection (effectively reflecting the internal quality and overall ripeness of tomato fruits), simple in structure, and easy to operate is of great practical significance and application value for improving tomato quality and enhancing the market competitiveness of the tomato industry. Utility Model Content
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-quality non-destructive tomato sorting device based on electrical characteristic parameter measurement. By detecting and analyzing the changes in electrical characteristic parameters of tomatoes in an alternating electric field, the ripeness of tomatoes can be detected, thereby achieving tomato sorting. The detection results are accurate and will not damage the tomatoes.
[0005] The objective of this utility model is achieved through the following technical solution:
[0006] A high-quality tomato non-destructive sorting device based on electrical characteristic parameter measurement includes a sorting box. Inside the sorting box, from bottom to top, are a detection chamber and a storage chamber. The detection chamber contains a main controller, an electrical characteristic parameter detector, an input pipe, a detection channel, and a detection component. An input port is located at the top of the sorting box. The input port, input pipe, and detection channel are sequentially connected. The detection component is located at the detection channel and electrically connected to the electrical characteristic parameter detector. The storage chamber is divided into a low-quality storage chamber and a high-quality storage chamber by a vertical partition. Both the top of the low-quality storage chamber and the top of the high-quality storage chamber have diversion pipes connected to the detection channel. An electric door is located at the connection point between the diversion pipes and the detection channel. The outer wall of the sorting box is equipped with an LCD screen, control buttons, and indicator lights. The electric door, LCD screen, control buttons, and indicator lights are all electrically connected to the main controller.
[0007] Furthermore, the detection assembly includes an electrode plate, a support column, and a spring. There are two electrode plates arranged opposite each other, forming a detection channel between them. The support column is fixed to the opposite side of the two electrode plates. The electrode plates are connected to the corresponding support columns via springs. The electrode plates are electrically connected to the electrical characteristic parameter detector.
[0008] Furthermore, both the inner walls of the low-quality storage chamber and the inner walls of the high-quality storage chamber are equipped with cushioning pads.
[0009] Furthermore, the top of the sorting box is equipped with a handling handle, and the handling handle is covered with a rubber protective cover.
[0010] Furthermore, the inlet is connected to a hinged door.
[0011] Furthermore, the bottom of the sorting box is equipped with support feet, and the bottom surface of the support feet is equipped with anti-slip pads.
[0012] Furthermore, the outer wall of the sorting box is also equipped with a signal receiver that is electrically connected to the main controller.
[0013] Compared with the prior art, the present invention has the following beneficial effects:
[0014] 1. This utility model detects the ripeness of tomatoes by detecting and analyzing the changes in electrical characteristic parameters of tomatoes in an alternating electric field, thereby achieving the sorting of tomatoes. The detection results are accurate and will not damage the tomatoes.
[0015] 2. The detection component of this utility model can adapt to the size of the tomato fruit and can detect tomatoes of different sizes.
[0016] 3. This utility model has a simple overall structure and is easy to operate, which improves the speed of ripeness and quality detection of tomatoes.
[0017] 4. This utility model can sort and store tomatoes of different quality levels separately, which facilitates the grading and use of the fruit and improves economic benefits. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the external structure of this utility model;
[0019] Figure 2 This is a schematic diagram of the internal structure of the present invention. Figure 1 ;
[0020] Figure 3 This is a schematic diagram of the internal structure of the present invention. Figure 2 .
[0021] In the diagram: 1. LCD screen; 2. Control buttons; 3. Signal receiver; 4. Support feet; 5. Handle; 6. Door open / close; 7. Indicator / alarm light; 8. Plug; 9. Main controller; 10. Electrical characteristic parameter detector; 11. Detection components; 12. Electrode plate; 13. Input pipe; 14. Electric door; 15. Diversion pipe; 16. Buffer pad; 17. Low-quality storage chamber; 18. High-quality storage chamber. Detailed Implementation
[0022] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.
[0023] like Figure 2 , Figure 3 As shown, a high-quality tomato non-destructive sorting device based on electrical characteristic parameter measurement includes a sorting box. Inside the sorting box, from bottom to top, are a detection chamber and a storage chamber. The detection chamber houses a main controller 9, an electrical characteristic parameter detector 10, an input pipe 13, a detection channel, and a detection component 11. An input port is located at the top of the sorting box. The input port, input pipe 13, and detection channel are sequentially connected. The detection component 11 is located at the detection channel and electrically connected to the electrical characteristic parameter detector 10. The storage chamber is divided into a low-quality storage chamber 17 and a high-quality storage chamber 18 by a vertical partition. A diversion pipe 15, communicating with the detection channel, is fixed to the top of both the low-quality storage chamber 17 and the high-quality storage chamber 18. An electric door 14 is installed at the connection between the diversion pipe 15 and the detection channel. A power interface and a power switch are installed on the outer wall of the sorting box. A power cord is connected to the power interface, and a plug 8 is connected to the power cord.
[0024] Plug 8 into the power supply to power the equipment. Turn on the power switch and place the tomatoes into the testing chamber through the inlet. The tomatoes fall into the testing channel through the inlet pipe 13. The electrical characteristic parameter detector 10 detects and collects the electrical characteristic parameters of the tomatoes through the detection component 11, and transmits the collected data to the main controller 9. The main controller 9 then processes and analyzes the data to determine the quality of the tomatoes. If the tomatoes are of high quality, the main controller 9 controls the electric door 14 of the diversion channel in the high-quality storage chamber 18 to open, allowing the high-quality tomatoes to fall into the high-quality storage chamber 18. If the tomatoes are of low quality, the main controller 9 controls the electric door 14 of the diversion channel in the low-quality storage chamber 17 to open, allowing the low-quality tomatoes to fall into the low-quality storage chamber 17. Cushioning pads 16, made of polyurethane, are laid on the inner walls of both the low-quality storage chamber 17 and the high-quality storage chamber 18 to prevent fruit damage from falls.
[0025] Tomatoes are a typical dielectric, with their internal electrons strongly bound to the atomic nuclei, making free movement difficult. As a dielectric, tomatoes primarily transmit, store, or record electrical effects through polarization, where the centers of positive and negative charges do not coincide, with the bound charges playing a dominant role. The main chemical components of tomato fruit include soluble sugars (such as glucose and fructose), organic acids (mainly citric acid and malic acid), soluble solids, vitamin C, cellulose, pectin, and various enzymes. Ripe tomatoes have an extremely high water content, typically exceeding 90%. During the ripening process of tomatoes, their internal water content and spatial distribution undergo significant changes, which can be macroscopically reflected through their electrical properties.
[0026] From a microscopic perspective, an electric field exists within the molecules of a tomato fruit, and the field strength varies dramatically within the molecular scale. Since directly measuring this microscopic field is extremely difficult, researchers typically focus on its macroscopic average value, which is converted into macroscopic electrical characteristic parameters such as complex impedance (Z) and complex permittivity (ε). The complex permittivity reflects the internal material properties of the tomato, while the complex impedance is related to the tomato's physical size and shape. By placing the tomato in an alternating electric field and detecting and analyzing the changes in these electrical parameters, its ripeness and internal quality can be effectively assessed.
[0027] The electrical properties of tomatoes mainly include conductivity and dielectric properties. Dielectric properties specifically refer to the response of bound charges in biomolecules to an applied electric field, while the dielectric constant is a key macroscopic parameter characterizing the electrical properties of a dielectric. The physiological structural characteristics of tomatoes can be characterized by their dielectric parameters (such as relative permittivity ε'r, dielectric loss factor tanδ, etc.). Studies have shown that measuring the electrical parameters of tomatoes in the frequency range of 500 kHz to 5 MHz is ideal. Within this frequency range, as the ripening of tomatoes increases, their complex impedance gradually decreases, while the relative permittivity continuously increases. Especially during the color-changing stage of tomatoes, the loss factor usually reaches its maximum value, while the complex impedance phase angle reaches its minimum value. These specific changes make dielectric property detection a very promising method for determining tomato ripeness and for non-destructive quality testing.
[0028] The dielectric properties of a tomato can be represented by its complex impedance Z or admittance Y and complex permittivity εr. Z or Y are physical constants of the tomato, related to its individual size; while εr reflects the material properties of the tomato pulp and is independent of its individual size. At a given frequency ω, a tomato can be equivalently represented by a parallel or series circuit model consisting of an ideal capacitor and a resistor. If the tomato is placed between parallel electrodes as the internal dielectric of a capacitor, its electrical characteristics in an alternating electric field can be modeled. By measuring and analyzing the parameter changes of this model, data on the tomato's ripeness and internal quality (such as sugar and acid content, firmness, etc.) can be obtained non-destructively.
[0029] like Figure 2As shown, based on the above analysis of the electrical characteristics of tomatoes, the detection component 11 includes electrode plates 12, support columns, and springs. Two electrode plates 12 are provided and arranged opposite each other, forming a detection channel between them. Support columns are fixed to opposite sides of the two electrode plates 12. The electrode plates 12 are connected to their respective support columns via springs, with insulation between the springs and the electrode plates 12. The electrode plates 12 are electrically connected to the electrical characteristic parameter detector 10. When a tomato falls into the detection channel, the distance between the two electrode plates 12 can be automatically adjusted by the extension and contraction of the springs, thus enabling adaptive detection of tomatoes of different sizes. When a tomato falls into the detection channel, the electrical characteristic parameter detector 10 acquires data signals such as dielectric constant and voltage through the electrode plates 12 and stores the acquired impedance values in its built-in register. The microcontroller reads the RGB values from the corresponding register in the signal acquisition unit and processes the read RGB values. Under the frequency set by the sinusoidal signal generator built into the electrical characteristic parameter detector 10, the tomato is placed between the two electrode plates 12 as the internal dielectric of the capacitor. The sinusoidal current output by the sinusoidal signal generator flows through the series circuit formed by the standard resistor R and the impedance Z between the electrodes. The voltages amplified by the same gain are U1 and U2. After equivalent algebraic operations, the complex impedance between the electrodes under test is obtained as: Z = RU1 / U2. The alternating electric field generated by the sinusoidal signal generator facilitates the detection of the dielectric characteristics of the tomato. The standard voltage and the equivalent resistance of the two electrode plates 12 are collected for signal processing. The main controller 9, as the central processing unit, processes and classifies the collected impedance characteristics.
[0030] like Figure 1 As shown, the outer wall of the sorting box is equipped with an LCD screen 1, control buttons 2, and indicator lights 7. The electric door 14, LCD screen 1, control buttons 2, and indicator lights 7 are all electrically connected to the main controller 9. The main controller 9 can send processed information to the LCD screen 1 for timely display. The control buttons 2 are used to control the operation or stop of the detection. The indicator lights 7 are used to indicate the equipment's operating status and to alarm for abnormal equipment operation. The electric door 14 consists of a high-speed, high-torque servo motor and a POM (polyoxymethylene) door body. The high-speed, high-torque servo motor is electrically connected to the main controller 9. The main controller 9 controls the high-speed, high-torque servo motor to open or close the POM door body. The specific structural composition and working principle are existing technologies and will not be described in detail here. In addition, the outer wall of the sorting box is also equipped with a signal receiver 3 electrically connected to the main controller 9. Through the signal receiver 3, communication with external remote control devices can be achieved, thereby controlling the equipment's operation. In this embodiment, the main controller 9 is a microcontroller, model STC89LE52; the liquid crystal display screen 1 is an LCD liquid crystal display screen, model LCD12864; the electrical characteristic parameter detector 10 is an LCR electronic measuring instrument; and the electrode plate 12 is a high-purity graphite electrode plate.
[0031] like Figure 1 As shown, a handling handle 5 is fixed to the top of the sorting box, and a rubber protective cover is fitted on the handling handle 5; an opening and closing door 6 is connected to the inlet by a hinge; a support foot 4 is fixed to the bottom of the sorting box, and an anti-slip pad is provided on the bottom surface of the support foot 4.
[0032] Finally, although embodiments of the present invention have been shown and described above, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A high-quality non-destructive sorting device for tomatoes based on electrical characteristic parameter measurement, characterized in that: The sorting box includes a detection chamber and a storage chamber arranged from bottom to top. The detection chamber is equipped with a main controller (9), an electrical characteristic parameter detector (10), an input pipe (13), a detection channel, and a detection component (11). The top of the sorting box is equipped with an input port. The input port, the input pipe (13), and the detection channel are connected in sequence. The detection component (11) is located at the detection channel and is electrically connected to the electrical characteristic parameter detector (10). The storage chamber is divided into a low-quality storage chamber (17) and a high-quality storage chamber (18) by a vertical partition. The top of the low-quality storage chamber (17) and the top of the high-quality storage chamber (18) are equipped with a diversion pipe (15) connected to the detection channel. An electric door (14) is provided at the connection between the diversion pipe (15) and the detection channel. The outer wall of the sorting box is equipped with an LCD screen (1), control buttons (2), and an indicator alarm light (7). The electric door (14), the LCD screen (1), the control buttons (2), and the indicator alarm light (7) are all electrically connected to the main controller (9).
2. The high-quality tomato non-destructive sorting equipment based on electrical characteristic parameter measurement according to claim 1, characterized in that: The detection component (11) includes an electrode plate (12), a support column and a spring. There are two electrode plates (12) and the two electrode plates (12) are arranged opposite each other. A detection channel is formed between the two electrode plates (12). The support column is fixed on the opposite side of the two electrode plates (12). The electrode plate (12) is connected to the corresponding support column through the spring. The electrode plate (12) is electrically connected to the electrical characteristic parameter detector (10).
3. The high-quality non-destructive sorting equipment for tomatoes based on electrical characteristic parameter measurement according to claim 1, characterized in that: Both the inner walls of the low-quality storage chamber (17) and the inner walls of the high-quality storage chamber (18) are provided with cushioning pads (16).
4. The high-quality tomato non-destructive sorting equipment based on electrical characteristic parameter measurement according to claim 1, characterized in that: The top of the sorting box is equipped with a handling handle (5), and a rubber protective cover is fitted on the handling handle (5).
5. The high-quality tomato non-destructive sorting equipment based on electrical characteristic parameter measurement according to claim 1, characterized in that: The inlet is connected to a hinged door (6).
6. The high-quality tomato non-destructive sorting equipment based on electrical characteristic parameter measurement according to claim 1, characterized in that: The bottom of the sorting box is provided with support feet (4), and the bottom surface of the support feet (4) is provided with anti-slip pads.
7. The high-quality tomato non-destructive sorting equipment based on electrical characteristic parameter measurement according to claim 1, characterized in that: The outer wall of the sorting box is also equipped with a signal receiver (3) that is electrically connected to the main controller (9).