Method for grading quality of tea leaves by using spectrum

Abstract

The invention discloses a method for grading the quality of tea leaves by using a spectrum, which comprises the following steps of: introducing tender shoots subjected to preliminary grading near a spectrum detection mechanism, and placing the spectrum detection mechanism in a space with constant illumination intensity; identifying the tea hair density condition of the tender shoots by using a spectrum detection mechanism; and performing quality grading on the corresponding tender shoots in combination with the obtained tea hair density condition and other grading standards. By the adoption of the scheme, tea quality grading is carried out through the density condition of the tea hair in a low-cost, rapid, simple and effective means, quantitative evaluation and grading can be carried out based on the density condition of the tea hair, the method is applied to a tea processing line, tea quality grading can be conveniently carried out, and the method is suitable for popularization and application. Quantitative evaluation can be carried out on the tea showing features, and the accuracy of tea tender shoot quality grading division is improved to a certain extent.

Description

Technical Field

[0001] The invention belongs to the technical field of tea bud quality grading, and in particular relates to a method for grading tea quality by using a spectrum (light beam). Background Art

[0002] The quality grade of high-end tea is usually divided according to the national standard "Basic Conditions for Tea Sensory Evaluation Room" based on the shape, color, wholeness, purity, internal quality, aroma, flavor thickness, soup color, and leaf bottom. They include special grade (tight, fine, uniform, visible hairs, and clean), first grade (tight, plump, tender, uniform, with relatively visible hairs), second grade (tight, relatively plump, tender, uniform, uniform hairs, relatively visible hairs, and clean), third grade (tight, uniform, with visible hairs), fourth grade (fat, tight, uniform, with relatively visible hairs), fifth grade (tight and uniform teas, with slightly visible hairs)...

[0003] As mentioned above, the visible characteristics of tea leaves are an important indicator in the process of tea quality grading. However, the visible characteristics of tea leaves are currently mainly evaluated by the naked eye with the help of a magnifying glass and by image recognition technology. When applied to tea processing lines, it is inconvenient and difficult to operate. More importantly, the existing scheme cannot quantitatively evaluate the visible characteristics of tea leaves, which to some extent affects the accuracy of tea bud quality grading. Summary of the invention

[0004] At least in view of the problems mentioned in the background technology, the present invention aims to provide a method for grading tea quality using spectrum, which is conducive to quantitative evaluation in the process of tea quality grading.

[0005] The present invention adopts the following technical solution.

[0006] A method for grading tea quality using spectrum, comprising the steps of: Step 1, introducing the tender buds after preliminary classification near the spectrum detection mechanism, and the spectrum detection mechanism is placed in a constant weak light intensity space; the weak light intensity in the present invention refers to the light intensity value not greater than 45Lx, and the preliminary classification refers to the initial classification of the picked tea leaves, such as single teeth are divided into one level, and one leaf and one tooth are divided into one level. The tender buds refer to single-teeth tea leaves, and the tender buds usually have white tea hairs, which can reflect monochromatic red light; Step 2, using a spectral detection mechanism to identify the density of tea leaves in the tender buds; Step 3, quality grading of the corresponding young buds is carried out based on the density of the obtained tea hairs and other grading standards. The other grading standards mainly refer to the common color, clarity and aroma indicators.

[0007] Furthermore, the spectral detection mechanism includes: a light emitter arranged directly above the detection position on the transmission belt, the light emitted by the light emitter is monochromatic red light; a light intensity sensor is arranged above the detection position side on the transmission belt, the light sensitive surface of the light intensity sensor is a curved surface, and the light intensity sensor is connected to the light intensity terminal.

[0008] Furthermore, a blowing mechanism is provided on the side of the conveyor belt, and the blowing mechanism includes a horizontally arranged support rod, an air nozzle is provided at the end of the support rod, and the air nozzle is connected to a compressed air supply system. A material receiving container is provided on the side of the conveyor belt and opposite to the blowing mechanism. The blowing mechanism is used to collect young sprouts that meet the grading requirements in the corresponding material receiving container.

[0009] Furthermore, the width of the photosensitive surface of the light intensity sensor is smaller than the length of the tender shoots, and the width of the photosensitive surface is a standard size, so that detection can be performed within a unit size on the tender shoots, reducing the impact of tender shoots of different lengths on the detection results.

[0010] Furthermore, the specific steps of using the spectrum detection mechanism to identify the density of tea hairs in the tender buds are as follows: S1, when the sprout moves to the detection position along with the conveyor belt, the conveyor belt is controlled to pause; S2, first turn on the light emitter, and then obtain the light intensity Lx1 fed back by the light intensity sensor; S3, comparing the obtained light intensity Lx1 with the light intensity threshold Lx0, and matching and grading the density of the tea hairs.

[0011] Further, in step 2, only a single sprout is located at the detection position.

[0012] Furthermore, in step 2, the length direction of the sprout is substantially parallel to the width direction of the photosensitive surface.

[0013] Furthermore, the detection position is a groove structure for accommodating the tender buds, and the inner depth of the groove structure is less than half of the diameter of the tender buds. This setting is intended to improve the accuracy of the tea leaf density recognition result.

[0014] Beneficial effect: The scheme of the present invention can realize the quality grading of tea leaves according to the density of tea hairs in a low-cost, fast, simple and effective way. It can perform quantitative evaluation and grading based on the density of tea hairs. It can be applied to tea processing lines to conveniently grade the quality of tea leaves, and can quantitatively evaluate the visible characteristics of tea hairs, thereby improving the accuracy of grading the quality of tea buds to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the spectrum detection mechanism in Example 1; Figure 2and Figure 3 This is a schematic diagram of the principle of using a spectral detection mechanism to identify the density of young tea buds in Example 1. DETAILED DESCRIPTION

[0016] The technical solution of the present invention is described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0017] Combination Figures 1 to 3 As shown, a method for grading tea quality by using spectrum adopts spectrum detection mechanism, which includes: a light emitter 4 arranged just above the detection position on the conveyor belt 1, the light emitted by the light emitter 4 is monochromatic red light; a light intensity sensor 6 is arranged above the detection position side on the conveyor belt 1, the light intensity sensor 6 has a photosensitive surface which is an arc surface, and the light intensity sensor 6 is connected to the light intensity terminal; a blowing mechanism is arranged on the side of the conveyor belt 1, the blowing mechanism includes a horizontally arranged support rod, an air nozzle 2 is arranged at the end of the support rod, and the air nozzle 2 is connected to the compressed air supply system, and a material receiving container 7 is arranged on the side of the conveyor belt 1 and opposite to the blowing mechanism; the photosensitive surface width of the light intensity sensor 6 is less than the length of the young buds 3. Among them, the detection position is a groove structure 5 for accommodating the young buds 3, and the inner concave depth of the groove structure 5 is less than half the diameter of the young buds 3. Since the young tea buds can be divided into multiple levels, a plurality of detection positions and corresponding blowing mechanisms can be arranged on the conveyor belt 1, such as Figure 1 As shown, the material receiving container 7 corresponding to the detection position 10 can be used to collect special-grade tea buds, and the material receiving container corresponding to the detection position 2 11 can be used to collect first-grade tea buds.

[0018] The method for grading tea quality using spectrum in this embodiment comprises the following steps: Step 1, introducing the tender shoots 3 after preliminary classification into the vicinity of the spectrum detection mechanism, and the spectrum detection mechanism is placed in a space with constant light intensity; there is no rain on the surface of the tender shoots 3 after preliminary classification; Step 2, using a spectral detection mechanism to identify the density of tea hairs in the young buds 3, specifically: S1, controlling the length direction of the tender bud 3 to be substantially parallel to the width direction of the photosensitive surface and to move along with the conveyor belt 1, and when the tender bud 3 moves along with the conveyor belt 1 to the detection position (at the same time, only a single tender bud 3 is located in the same groove structure 5 at the detection position), controlling the conveyor belt 1 to pause; S2, first turn on the light emitter 4, and then obtain the light intensity Lx1 fed back by the light intensity sensor 6; S3, comparing the obtained light intensity Lx1 with the light intensity threshold Lx0, and matching and grading the density of the tea hairs; Step 3, grading the quality of the corresponding young buds 3 based on the density of the obtained tea hairs and other grading standards.

[0019] In the present invention, the tender buds refer to tea buds with white tea hairs on the tender buds. The white tea hairs can reflect monochromatic red light, and the chlorophyll in the tea buds can absorb monochromatic red light.

[0020] In one application scenario, combined Figure 2 As shown, when the tea hairs on the surface of the tender buds 3 are dense, a large amount of red light emitted by the light emitter 4 is reflected to the photosensitive surface of the light intensity sensor 6, so that the light intensity Lx1 at this time is monitored to be relatively large; Figure 3 As shown, when the tea hairs on the surface of the tender buds 3 are sparse, only a small amount of the red light emitted by the light emitter 4 is reflected to the photosensitive surface of the light intensity sensor 6, so that the light intensity Lx1 monitored at this time is relatively small.

[0021] When in use, the technicians in this field and tea experts predetermine the standard samples of tender buds 3 of each level according to the tea tender bud variety, and determine the light intensity interval values ​​(i.e., light intensity threshold value Lx0) corresponding to the standard samples of tender buds 3 of each level. If the light intensity interval value Lx0=185~192Lx corresponding to the special tender buds 3 of a certain variety as the standard sample, the light intensity interval value Lx0=168~184Lx corresponding to the first-level tender buds 3 of the variety as the standard sample, the light intensity interval value Lx0=142~167Lx corresponding to the second-level tender buds 3 of the variety as the standard sample, the light intensity interval value Lx0=111~141Lx corresponding to the third-level tender buds 3 of the variety as the standard sample, the light intensity interval value Lx0=87~110Lx corresponding to the fourth-level tender buds 3 of the variety as the standard sample, and the light intensity interval value Lx0=52~86Lx corresponding to the fifth-level tender buds 3 of the variety as the standard sample. Furthermore, if the light intensity Lx1=181 corresponding to the Nth tender bud is detected during the tea quality grading process, then the Nth tender bud can be preliminarily classified as a first-level tender bud, and then the compressed air supply system can be controlled to open and blow the tender bud 3 into the corresponding material receiving container 7; if the light intensity Lx1=124 corresponding to the N+1th tender bud is detected during the tea quality grading process, then the N+1th tender bud can be preliminarily classified as a third-level tender bud.

[0022] By adopting the scheme of the embodiment, it is not necessary to use high-precision visual terminal photography and complex algorithms to evaluate image features, and the required light intensity sensor and light emitter cost is relatively lower, and a low-cost, fast, simple and effective means is realized to evaluate the grade of tea buds by identifying the density of tea hairs. The time consumption of the density evaluation of tea hairs of a single bud in the batch grading process can be controlled within five seconds. The operation process is relatively convenient and the operation difficulty is small. The density of tea hairs can be quantitatively evaluated, which is conducive to more accurate grading of tea quality. In the existing scheme, it is usually necessary to magnify the image dozens or even hundreds of times before the corresponding operation can be performed, because the diameter of tea hairs is only about ten microns, and the image recognition and algorithm processing involved are very troublesome and difficult. In short, by adopting the scheme of the present invention, a low-cost, fast, simple and effective means is realized to grade the quality of tea by the density of tea hairs, and quantitative evaluation and grading can be performed based on the density of tea hairs. It can be applied to the tea processing line to easily grade the quality of tea, and can quantitatively evaluate the visible characteristics of tea hairs, which improves the accuracy of the grading of the quality of tea buds to a certain extent.

Claims

1. A method for grading tea quality using spectrum, characterized in that the steps include: Step 1, introducing the tender shoots after preliminary classification into the vicinity of a spectrum detection mechanism, and placing the spectrum detection mechanism in a constant weak light intensity space; Step 2, using a spectral detection mechanism to identify the density of tea leaves in the tender buds; Step 3, grading the quality of the corresponding young buds 3 based on the density of the obtained tea hairs and other grading standards.

2. The method for grading tea quality by using spectrum according to claim 1, characterized in that: The spectrum detection mechanism includes: a light emitter arranged just above the detection position on the transmission belt, the light emitted by the light emitter is monochromatic red light; a light intensity sensor is arranged above the detection position on the transmission belt, the light sensitive surface of the light intensity sensor is a curved surface, and the light intensity sensor is connected to the light intensity terminal.

3. The method for grading tea quality by utilizing spectrum according to claim 2, characterized in that: A blowing mechanism is arranged on the side of the conveyor belt, which includes a horizontally arranged support rod, an air nozzle is arranged at the end of the support rod, and the air nozzle is connected to a compressed air supply system. A material receiving container is arranged on the side of the conveyor belt and opposite to the blowing mechanism.

4. The method for grading tea quality by using spectrum according to claim 3, characterized in that: The light-sensitive surface width of the light intensity sensor is smaller than the length of the tender shoot.

5. The method for grading tea quality by using spectrum according to any one of claims 2 to 4, characterized in that: The specific steps of using the spectral detection mechanism to identify the density of tea leaves in young buds are as follows: S1, when the sprout moves to the detection position along with the conveyor belt, the conveyor belt is controlled to pause; S2, first turn on the light emitter, and then obtain the light intensity Lx1 fed back by the light intensity sensor; S3, comparing the obtained light intensity Lx1 with the light intensity threshold Lx0, and matching and grading the density of the tea hairs.

6. The method for grading tea quality by using spectrum according to claim 5, characterized in that: In step 2, only a single sprout is located at the detection position.

7. The method for grading tea quality by using spectrum according to claim 6, characterized in that: In step 2, the length direction of the sprout is substantially parallel to the width direction of the photosensitive surface.

8. The method for grading tea quality by using spectrum according to claim 7, characterized in that: The detection position is a groove structure for accommodating the tender sprouts, and the inner concave depth of the groove structure is less than half of the diameter of the tender sprouts.

Images