Strawberry maturity detection method and system based on spectral illuminometer

Abstract

The invention discloses a strawberry maturity detection method and system based on a spectral illuminometer. The method comprises the following steps: constructing a strawberry maturity detection device based on a spectral illuminometer sensor; the position of a target strawberry is determined according to distance information obtained by the 3D-TOF infrared camera, then adaptive adjustment processing is performed on the strawberry maturity detection device, shooting processing is performed on the target strawberry, and an infrared spectrum curve graph of the target strawberry is obtained; and determining the maturity of the target strawberry according to the infrared spectrum curve graph of the target strawberry. Wide-angle loss of strawberry images can be prevented, consistency of visual fields is ensured, energy consumption of the instrument is saved, and the strawberry maturity detection precision is improved. The strawberry maturity detection method and system based on the spectral illuminometer can be widely applied to the technical field of strawberry maturity identification.

Description

Technical Field

[0001] The present invention relates to the technical field of strawberry maturity recognition, and in particular to a strawberry maturity detection method and system based on a spectral illuminometer. Background Art

[0002] Currently, the main methods for detecting strawberry ripeness include visual recognition, electrochemical measurement, and infrared spectroscopy. Visual recognition primarily uses convolutional neural networks (CNNs) or YOLO algorithms to identify strawberry images. Electrochemical methods primarily measure the internal resistance of the strawberry fruit to determine its ripeness. Infrared spectroscopy uses an infrared light source to emit infrared waves. Depending on the ripeness of the strawberry fruit, the chemical substances diffused on the surface absorb and diffract some of the infrared waves differently. Therefore, the ripeness of the strawberry fruit can be determined by measuring the infrared diffraction spectrum of the chemical substances diffused on the surface and diffracting the infrared waves. Except for visual detection, the remaining detection methods are still in the laboratory stage. Moreover, the more mature infrared spectroscopy method is only used to identify white strawberries in indoor environments and is not suitable for determining the ripeness of strawberries before robotic harvesting. This results in waste of strawberries. Furthermore, the electrochemical method requires contact with the strawberry surface to measure its internal resistance, which can damage the fruit itself. Traditional infrared spectroscopy also requires high equipment requirements and is not energy-efficient. Summary of the Invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a strawberry maturity detection method and system based on a spectrophotometer, which can prevent the wide-angle loss of strawberry images, ensure the consistency of the field of view size, save energy consumption of the instrument, and thus improve the accuracy of strawberry maturity detection.

[0004] The first technical solution adopted by the present invention is: a strawberry maturity detection method based on a spectrophotometer, comprising the following steps:

[0005] Constructing a strawberry maturity detection device based on spectral illumination sensor;

[0006] The target strawberry position is determined based on the distance information obtained by the 3D-TOF infrared camera, and then the strawberry maturity detection device is adaptively adjusted and the target strawberry is photographed to obtain an infrared spectrum curve graph of the target strawberry;

[0007] The maturity of the target strawberry is determined according to the infrared spectrum curve of the target strawberry.

[0008] Furthermore, the strawberry maturity detection device specifically includes a 3D-TOF infrared camera, a lens, a spectroscopic grating and a spectral illumination sensor (hereinafter referred to as the sensor), the center point of the lens, the center point of the spectroscopic grating and the center point of the sensor are on the same horizontal straight line, and the lens, the spectroscopic grating and the sensor are arranged longitudinally in sequence from front to back, the position of the 3D-TOF infrared camera and the lens are on the same horizontal plane, and the 3D-TOF infrared camera and the lens are arranged horizontally in sequence from left to right, and the target strawberry is arranged on the side of the strawberry maturity detection device with the lens.

[0009] Further, the distance information obtained according to the 3D-TOF infrared camera is used to determine the target strawberry position, and then the strawberry maturity detection device is adaptively adjusted and processed, and the target strawberry is photographed to obtain the infrared spectrum curve of the target strawberry, which specifically includes:

[0010] The target strawberry position is determined according to the distance information of the 3D-TOF infrared camera, and the strawberry maturity detection device is adaptively adjusted to obtain an adjusted strawberry maturity detection device;

[0011] The 3D-TOF infrared camera in the adjusted strawberry maturity detection device emits an infrared light source to the target strawberry, and the infrared diffraction wave of the target strawberry is obtained by the sensor;

[0012] The infrared diffraction waves of the target strawberries are subjected to spectroscopic processing by the adjusted spectroscopic grating in the strawberry maturity detection device to obtain an infrared spectrum curve graph of the target strawberries.

[0013] Furthermore, the step of performing adaptive adjustment processing on the strawberry maturity detection device to obtain an adjusted strawberry maturity detection device specifically includes:

[0014] The 3D-TOF infrared camera measures the round-trip time of infrared light from the target strawberry to the 3D-TOF infrared camera, and calculates the actual distance between the target strawberry and the camera lens.

[0015] Determine the focal length of the lens based on the actual distance from the target strawberry to the lens, the field of view of the lens, and the effective area length of the sensor;

[0016] Determine the grating density and period of the spectroscopic grating according to actual needs;

[0017] Obtain the wavelength of the infrared light source emitted by the lens, set the diffraction order of the spectroscopic grating and determine the maximum dispersion angle of the spectroscopic grating in combination with the grating period of the spectroscopic grating;

[0018] The effective width of the spectroscopic grating is determined by combining the grating period and the grating density of the spectroscopic grating;

[0019] Obtain the sensor size information, the effective width of the beam splitter grating, the focal length of the lens, and the field of view of the lens to determine the distance between the lens and the beam splitter grating;

[0020] The wavelength of the infrared light source emitted by the combined lens, the maximum dispersion angle of the beam splitter, and the field of view of the lens determine the distance between the beam splitter and the sensor.

[0021] The distance between the spectrometer and the sensor and the field of view of the lens are combined to determine the point offset of the image on the sensor.

[0022] The imaging point offset distance is determined according to the imaging point offset on the sensor, and the strawberry maturity detection device is adaptively adjusted based on the distance between the lens and the spectroscopic grating and the distance between the spectroscopic grating and the sensor to construct an adjusted strawberry maturity detection device.

[0023] Furthermore, the calculation expression for determining the focal length of the lens is specifically as follows:

[0024]

[0025] In the above formula, f represents the focal length of the lens, L represents the actual distance from the target strawberry to the lens, θ represents the field of view of the lens, and ω represents the effective area length of the sensor.

[0026] Furthermore, the calculation expression for determining the maximum dispersion angle of the spectroscopic grating is specifically as follows:

[0027]

[0028] In the above formula, θ1 represents the maximum dispersion angle of the spectroscopic grating, m represents the diffraction order of the spectroscopic grating, τ represents the wavelength of the infrared light source emitted by the lens, and d represents the grating period of the spectroscopic grating.

[0029] Furthermore, the calculation expression for determining the distance between the lens and the beam splitter grating is specifically as follows:

[0030]

[0031] In the above formula, V represents the distance between the lens and the spectrometer, W g represents the effective width of the spectroscopic grating, f represents the focal length of the lens, θ represents the field of view of the lens, and ω represents the length of the effective area of ​​the sensor.

[0032] Furthermore, the calculation expression for determining the distance between the spectroscopic grating and the sensor is specifically as follows:

[0033]

[0034] In the above formula, V represents the distance between the lens and the spectroscopic grating, f represents the focal length of the lens, θ1 represents the maximum dispersion angle of the spectroscopic grating, τ represents the wavelength of the infrared light source emitted by the lens, and l represents the distance between the spectroscopic grating and the sensor.

[0035] Furthermore, the calculation expression for determining the offset of the imaging point on the sensor is specifically as follows:

[0036]

[0037] In the above formula, Δx represents the offset of the imaging point on the sensor, ω represents the length of the effective area of ​​the sensor, and θ represents the field of view of the lens.

[0038] The second technical solution adopted by the present invention is: a strawberry maturity detection system based on a spectrophotometer, comprising:

[0039] The first module is used to build a strawberry maturity detection device based on a spectral illumination sensor;

[0040] The second module is used to determine the target strawberry position according to the 3D-TOF infrared camera distance information, and then perform adaptive adjustment processing on the strawberry maturity detection device and shoot the target strawberry to obtain the infrared spectrum curve graph of the target strawberry;

[0041] The third module is used to determine the maturity of the target strawberry based on the infrared spectrum curve of the target strawberry.

[0042] The method and system of the present invention have the following beneficial effects: the present invention constructs a strawberry maturity detection device based on a spectral illumination sensor, adopts an infrared 3D-TOF camera as a distance detector and an infrared light source, thereby achieving device integration and miniaturization, saving energy consumption, and reducing the requirement for device volume; further, the target strawberry position is determined according to the distance information of the 3D-TOF infrared camera, and then the strawberry maturity detection device is adaptively adjusted and the target strawberry is photographed to obtain an infrared spectrum curve graph of the target strawberry; the strawberry image captured by the lens can be kept consistent with the strawberry image captured by the sensor of the present invention, wide-angle loss can be prevented, and consistency of field of view can be ensured; finally, the maturity of the target strawberry is determined according to the infrared spectrum curve graph of the target strawberry; the detection can be completed without physical contact, thus avoiding the problem of strawberry damage that may be caused by contact measurement, and further improving the detection efficiency and the fruit integrity rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1This is a flowchart of a method for detecting strawberry maturity based on a spectral illuminometer according to the present invention;

[0044] Figure 2 This is a structural block diagram of a strawberry maturity detection system based on a spectral illuminometer according to the present invention;

[0045] Figure 3 is a schematic diagram of a strawberry maturity detection sensor provided by a specific embodiment of the present invention;

[0046] Figure 4 is a schematic diagram of a strawberry maturity detection device provided by a specific embodiment of the present invention;

[0047] Figure 5 It is a schematic diagram of the process of identifying the maturity of strawberry fruit provided by a specific embodiment of the present invention. DETAILED DESCRIPTION

[0048] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are provided for ease of description only and do not limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted based on the understanding of those skilled in the art.

[0049] First, it should be noted that the embodiment of the present invention mainly uses a 3D-TOF infrared camera as an infrared light source to emit infrared waves, and the chemical substances dispersed on the surface of the strawberry fruit absorb and diffract some infrared waves. Under different ripening conditions, the surface chemical substances dispersed on the surface of the strawberry fruit are also different. Therefore, the maturity of the strawberry fruit can be judged by measuring the situation of the chemical substances dispersed on the surface of the strawberry fruit absorbing and diffracting the infrared waves. Finally, the invention detects the diffracted infrared waves and obtains its spectrum. Then, the spectral data is input into a microprocessor and compared with a set value to finally judge the maturity of the strawberry.

[0050] Reference Figure 1 The present invention provides a method for detecting strawberry maturity based on a spectrophotometer, the method comprising the following steps:

[0051] S100, constructing a strawberry maturity detection device based on a spectral illumination sensor;

[0052] In this embodiment, if Figure 3 and Figure 4As shown, the strawberry maturity detection device specifically includes a 3D-TOF infrared camera, a lens, a spectroscopic grating and a spectral illumination sensor (hereinafter referred to as the sensor), the center point of the lens, the center point of the spectroscopic grating and the center point of the sensor are on the same horizontal straight line, and the lens, the spectroscopic grating and the sensor are arranged longitudinally in sequence from front to back, the position of the 3D-TOF infrared camera and the lens are on the same horizontal plane, and the 3D-TOF infrared camera and the lens are arranged horizontally in sequence from left to right, and the target strawberry is arranged on the side of the strawberry maturity detection device with the lens.

[0053] S200, determining the target strawberry position according to the distance information obtained by the 3D-TOF infrared camera, and then performing adaptive adjustment processing on the strawberry maturity detection device and photographing the target strawberry to obtain an infrared spectrum curve graph of the target strawberry;

[0054] First, it should be noted that according to the detection situation of the 3D-TOF infrared camera selected in the embodiment of the present invention, the detection range of the infrared camera is within 1.5 meters, and the infrared detection system only starts detection within 0.5 meters.

[0055] S210, determining the target strawberry position according to the 3D-TOF infrared camera distance information, and then adaptively adjusting the strawberry maturity detection device to obtain an adjusted strawberry maturity detection device;

[0056] S211, measuring the round-trip time of infrared light from the target strawberry to the 3D-TOF infrared camera according to the 3D-TOF infrared camera, and obtaining the actual distance from the target strawberry to the camera lens;

[0057] S212, according to the actual distance of target strawberry to lens, the field angle of lens and the effective area length of sensor, determine the focal length of lens;

[0058] In this embodiment, in order to keep the strawberry image captured by the 3D-TOF infrared camera consistent with the strawberry image captured by the sensor of the present invention, and in order to prevent wide-angle loss and to ensure the consistency of visual field size, to simplify calculation, the embodiment of the present invention only discusses the field angle in the horizontal direction. The field angle θ of the lens selected in the embodiment of the present invention is 60 °, which is consistent with the lens field angle of the 3D-TOF infrared camera. Therefore, the calculation expression for determining the focal length of the lens is specifically as follows:

[0059]

[0060] In the above formula, f represents the focal length of the lens, L represents the actual distance from the target strawberry to the lens, θ represents the field of view of the lens, and ω represents the effective area length of the sensor.

[0061] In some specific embodiments, the field of view is the visual range that the lens can capture, and ω is the length of the sensor's effective sensing area. To reduce equipment costs and meet usage requirements, the present invention uses a 1 / 3-inch sensor. Since the design only discusses values ​​in the horizontal direction, only the narrowest side is selected for calculation. The 1 / 3-inch sensor used in the present invention has a narrowest side length of 3.6 mm, so ω is 3.6 mm. Substituting the relevant values ​​into the solution, we obtain:

[0062]

[0063] Therefore, choose a focal length of 80mm or a focal length equivalent to 80mm.

[0064] S213, selecting and determining the grating density of the spectroscopic grating and the grating period of the spectroscopic grating according to actual needs;

[0065] In this embodiment, based on the use requirements and referring to the relevant values ​​of ordinary spectrometers, it is concluded that this design should use a 1200 lines / mm grating. The calculation expression of the grating period of the spectroscopic grating is as follows:

[0066]

[0067] Where d is the grating period, that is, the grating constant, and N is the grating density.

[0068] In the embodiment of the present invention, N=1200 lines / mm. Substituting the above values ​​into the formula yields:

[0069]

[0070] Therefore, in the specific embodiment of the present invention, the grating period is selected to be 0.0008333 mm.

[0071] S214, obtaining the wavelength of the infrared light source emitted by the lens, setting the diffraction order of the spectroscopic grating and determining the maximum dispersion angle of the spectroscopic grating in combination with the grating period of the spectroscopic grating;

[0072] In the embodiment of the present invention, θ1 is the maximum dispersion angle, and its calculation formula is as follows:

[0073]

[0074] In the above formula, θ1 represents the maximum dispersion angle of the spectroscopic grating, m represents the diffraction order of the spectroscopic grating, τ represents the wavelength of the infrared light source emitted by the lens, and d represents the grating period of the spectroscopic grating.

[0075] In some specific embodiments, let m = 1, τ be the maximum infrared wavelength, and according to experimental measurements, the infrared wavelength in this system is 288 mm. Substituting the relevant values ​​into the following formula yields:

[0076] θ1=20.1°

[0077] Therefore, the maximum dispersion angle of the spectroscopic grating is determined to be 20.1°.

[0078] S215, determining the effective width of the spectroscopic grating based on the grating period and the grating density of the spectroscopic grating;

[0079] In the embodiment of the present invention, the grating-related values ​​are substituted into the diffraction order calculation formula to obtain:

[0080] d×sinθ1=mτ

[0081] m≈0.989

[0082] m needs to be an integer, so the value is m=1. Therefore, the diffraction order m is m=1.

[0083] The effective width of the grating is W g , the grating density is N, n is the total number of gratings, in order to completely score the light on the sensor, it is necessary to reach 1200 lines / mm within the range of 3.6mm, which means n is 4320. The calculation expression of the effective width of the grating is:

[0084] W g =n×d

[0085] Substituting the numerical values, we can get:

[0086] W g =4320×0.0008333=3.599856≈3.6

[0087] Therefore, the effective width of the grating selected in the specific embodiment of the present invention is 3.6 mm.

[0088] S216, obtaining the size information of the sensor, and determining the distance between the lens and the spectroscopic grating based on the effective width of the spectroscopic grating, the focal length of the lens, and the field of view of the lens;

[0089] In the embodiment of the present invention, the distance between the lens and the grating is V, which is expressed as follows:

[0090]

[0091] Where W is the effective length of the grating, f is the focal length of the lens, which is 80 mm in this invention, θ is the field of view of the lens, which is 60° in this invention, and ω is the sensor size, which is 3.6 mm in this invention. Substituting the above values ​​into the equation, we get:

[0092] V≈138.6481=138.65mm

[0093] Therefore, the distance between the lens and the beam splitter grating is determined to be 138.65 mm.

[0094] S217, combining the wavelength of the infrared light source emitted by the 3D-TOF infrared camera, the maximum dispersion angle of the beam splitter grating, and the field of view of the lens to determine the distance between the beam splitter grating and the sensor;

[0095] In the embodiment of the present invention, assuming that the distance between the grating and the sensor is l, the calculation formula is as follows:

[0096]

[0097] In the above formula, V represents the distance between the lens and the spectroscopic grating, f represents the focal length of the lens, θ1 represents the maximum dispersion angle of the spectroscopic grating, τ represents the wavelength of the infrared light source emitted by the 3D-TOF infrared camera, and l represents the distance between the spectroscopic grating and the sensor.

[0098] S218. Determine the offset of the imaging point on the sensor based on the distance between the beam splitter grating and the sensor and the field of view angle of the lens;

[0099] In the embodiment of the present invention, the relationship between the imaging point offset Δx on the sensor and the distance l from the grating to the sensor is:

[0100] Δx=l×tanθ

[0101] Here, Δx can be derived from the sensor size and field of view.

[0102] In a specific embodiment of the present invention, the sensor width ω = 3.6 mm, the field of view angle θ = 60°, and the sensor half-width corresponds to the image height, that is, the imaging point offset Δx is:

[0103]

[0104] In the above formula, Δx represents the offset of the imaging point on the sensor, ω represents the length of the effective area of ​​the sensor, and θ represents the field of view of the lens.

[0105] Further, substitute the numerical value:

[0106]

[0107] Therefore, the point offset of the image on the sensor is determined to be 1.8 mm.

[0108] S219. Determine an image point offset distance according to the point offset of the image on the sensor, and adaptively adjust the strawberry maturity detection device based on the distance between the lens and the spectroscopic grating and the distance between the spectroscopic grating and the sensor to construct an adjusted strawberry maturity detection device.

[0109] In the embodiment of the present invention, substitute the formula The point offset distance of the image is:

[0110]

[0111] Therefore, the imaging point offset distance of the embodiment of the present invention is 4.9 mm.

[0112] S220, emitting an infrared light source to the target strawberry through the 3D-TOF infrared camera in the adjusted strawberry maturity detection device, and obtaining infrared diffraction waves of the target strawberry through the sensor;

[0113] S230 , performing spectroscopic processing on the infrared diffraction waves of the target strawberries by using the adjusted spectroscopic grating in the strawberry maturity detection device to obtain an infrared spectrum curve graph of the target strawberries.

[0114] Specifically, the focal length of the instrument is adjusted based on the positional information, ensuring that the focal length is within the optimal detection range and that the target strawberry is located at the center of the instrument's visual field, thereby reducing interference. Subsequently, infrared waves diffracted by chemical substances on the strawberry surface are received. Because these waves are adjusted in distance, only the target strawberry fruit is located at the center of the image, minimizing interference. Subsequently, the infrared waves diffracted by the strawberry fruit surface are processed by a spectroscopic grating to produce an infrared spectrum curve of the target strawberry fruit.

[0115] S300: Determine the maturity of the target strawberry according to the infrared spectrum curve of the target strawberry.

[0116] Specifically, the spectrum curve is uploaded to the host computer and compared with the set value, and the ripeness of the strawberries is determined according to the set value.

[0117] In summary, if Figure 5As shown, the embodiment of the present invention 3D-TOF infrared camera first shoots strawberry image, identifies the position of strawberry and reads the position and size information of strawberry, and these information are sent to the host computer to judge whether position information meets the condition of infrared identification (in the present invention, the condition is set as the distance of strawberry fruit from camera is 0.5m, and strawberry fruit must be located at the center of the picture simultaneously) if do not meet identification position, mechanical arm can adjust position according to position information, then continues to circulate said process.If meet setting position information, the strawberry position information adjustment lens focal length read according to 3D-TOF camera in the middle of strawberry maturity recognition instrument, so that the data of target strawberry are accurately received, then start to receive the infrared wave (the infrared wave source of strawberry fruit mainly contains sunlight and the infrared wave that 3D-TOF infrared camera sends when scanning) of strawberry fruit surface diffraction, and convert it into the infrared diffraction spectrogram of this strawberry fruit.According to the infrared diffraction spectrogram of strawberry fruit, the maturity of strawberry fruit is distinguished, and then for next step mechanization picking and mechanization sorting lay the foundation.

[0118] Therefore, the embodiment of the present invention mainly uses a 3D-TOF infrared camera as an infrared light source to emit infrared waves to illuminate strawberries, while simultaneously obtaining the position information of the strawberries. Based on the position information, the focal length of the lens in the instrument of the present invention is adjusted so that its focal length is within the optimal detection range and the target strawberry is located at the visual center of the instrument of the present invention, thereby reducing interference. The instrument of the present invention then receives infrared waves diffracted by chemical substances on the strawberry surface. Since the distance is adjusted, only the target strawberry fruit is in the center of the image, so interference can be minimized. Subsequently, the infrared waves diffracted by the strawberry fruit surface are processed by a spectroscopic grating to obtain an infrared spectrum curve graph of the target strawberry fruit. The spectrum curve graph is uploaded to the host computer and compared with the set value. The set value is used to determine the ripeness of the strawberries, thereby laying the foundation for subsequent mechanical picking. Compared with traditional prism light splitting, this method reduces the loss rate of light in the prism and reduces the structural weight, making it easier to configure it on a robotic arm.

[0119] Compared with the existing technology, the innovation of the embodiments of the present invention lies in the combination of its compact design and efficient recognition capabilities. Compared with traditional multi-spectrometers and industrial-grade infrared cameras, the maximum size of the present invention does not exceed 300 mm, which achieves high integration and miniaturization, and can be flexibly assembled on small robots, greatly broadening the scope of practical application. Traditional equipment is usually limited to laboratory and indoor environments, and is rarely used directly in field picking. The present invention not only significantly improves the accuracy of strawberry maturity identification, but also greatly reduces the requirements for terminal hardware performance and optimizes the calculation process, thereby effectively reducing the cost of strawberry picking robots, significantly improving picking efficiency, and laying a solid foundation for its practical application.

[0120] Finally, it should be noted that for the special variety of white strawberries, the embodiment of the present invention shows significant advantages in recognition effect. The traditional visual recognition method has a success rate of only about 50% for white strawberries. The embodiment of the present invention uses infrared spectroscopy to increase the recognition rate to more than 80%, which makes up for the shortcomings of traditional methods in specific scenarios. At the same time, compared with the electrochemical method, the embodiment of the present invention can complete the detection without physical contact, avoiding the problem of strawberry damage caused by contact measurement, and further improving the detection efficiency and fruit integrity rate. This non-contact detection method not only improves the detection speed, but also reduces damage to strawberry fruits. It is particularly suitable for complex scenarios such as field picking, and demonstrates significant technical advantages and practical value.

[0121] Reference Figure 2 , a strawberry maturity detection system based on a spectral illuminometer, comprising:

[0122] The first module 201 is used to construct a strawberry maturity detection device based on a spectral illumination sensor;

[0123] The second module 202 is used to determine the target strawberry position according to the 3D-TOF infrared camera distance information, and then perform adaptive adjustment processing on the strawberry maturity detection device and photograph the target strawberry to obtain an infrared spectrum curve graph of the target strawberry;

[0124] The third module 203 is used to determine the maturity of the target strawberry according to the infrared spectrum curve of the target strawberry.

[0125] The contents of the above method embodiments are all applicable to the present system embodiments. The functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0126] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A strawberry maturity detection method based on a spectrophotometer, characterized in that, The following steps are involved: Constructing a strawberry maturity detection device based on a spectral illuminance sensor; The target strawberry position is determined based on the distance information obtained by the 3D-TOF infrared camera, and then the strawberry maturity detection device is adaptively adjusted and the target strawberry is photographed to obtain an infrared spectrum curve graph of the target strawberry; The maturity of the target strawberry is determined according to the infrared spectrum curve of the target strawberry.

2. A strawberry maturity detection method based on a spectrophotometer according to claim 1, characterized in that, The strawberry maturity detection device specifically includes a 3D-TOF infrared camera, a lens, a spectroscopic grating, and a spectral illumination sensor (hereinafter referred to as the sensor). The center point of the lens, the center point of the spectroscopic grating, and the center point of the sensor are on the same horizontal line, and the lens, the spectroscopic grating, and the sensor are arranged vertically in sequence from front to back. The position of the 3D-TOF infrared camera and the lens are on the same horizontal plane, and the 3D-TOF infrared camera and the lens are arranged horizontally in sequence from left to right. The target strawberry is arranged on the side of the strawberry maturity detection device with the lens.

3. A strawberry maturity detection method based on a spectrophotometer according to claim 2, characterized in that, The step of determining the target strawberry position according to the 3D-TOF infrared camera distance information, then adaptively adjusting the strawberry maturity detection device and photographing the target strawberry, and obtaining the infrared spectrum curve graph of the target strawberry specifically includes: The target strawberry position is determined according to the distance information of the 3D-TOF infrared camera, and the strawberry maturity detection device is adaptively adjusted to obtain an adjusted strawberry maturity detection device; The 3D-TOF infrared camera in the adjusted strawberry maturity detection device emits an infrared light source to the target strawberry, and the infrared diffraction wave of the target strawberry is obtained by the sensor; The infrared diffraction waves of the target strawberries are subjected to spectroscopic processing by the adjusted spectroscopic grating in the strawberry maturity detection device to obtain an infrared spectrum curve graph of the target strawberries.

4. A strawberry maturity detection method based on a spectrophotometer according to claim 3, characterized in that, The step of performing adaptive adjustment processing on the strawberry maturity detection device to obtain an adjusted strawberry maturity detection device specifically includes: The 3D-TOF infrared camera measures the round-trip time of infrared light from the target strawberry to the 3D-TOF infrared camera, and calculates the actual distance between the target strawberry and the camera lens. Determine the focal length of the lens based on the actual distance from the target strawberry to the lens, the field of view of the lens, and the effective area length of the sensor; Determine the grating density and period of the spectroscopic grating according to actual needs; Obtain the wavelength of the infrared light source emitted by the 3D-TOF infrared camera, set the diffraction order of the spectroscopic grating, and determine the maximum dispersion angle of the spectroscopic grating based on the grating period of the spectroscopic grating; The effective width of the spectroscopic grating is determined by combining the grating period and the grating density of the spectroscopic grating; Obtain the sensor size information, the effective width of the beam splitter grating, the focal length of the lens, and the field of view of the lens to determine the distance between the lens and the beam splitter grating; The wavelength of the infrared light source emitted by the combined lens, the maximum dispersion angle of the beam splitter, and the field of view of the lens determine the distance between the beam splitter and the sensor. The distance between the spectrometer and the sensor and the field of view of the lens are combined to determine the point offset of the image on the sensor. The image point offset distance is determined according to the imaging point offset on the sensor, and the strawberry maturity detection device is adaptively adjusted based on the distance between the lens and the spectroscopic grating and the distance between the spectroscopic grating and the sensor to construct an adjusted strawberry maturity detection device.

5. A strawberry maturity detection method based on a spectrophotometer according to claim 4, characterized in that, The calculation expression for determining the focal length of the lens is specifically as follows: In the above formula, f represents the focal length of the lens, L represents the actual distance from the target strawberry to the lens, θ represents the field of view of the lens, and ω represents the effective area length of the sensor.

6. A strawberry maturity detection method based on a spectrophotometer according to claim 4, characterized in that, The calculation expression for determining the maximum dispersion angle of the spectroscopic grating is specifically as follows: In the above formula, θ1 represents the maximum dispersion angle of the spectroscopic grating, m represents the diffraction order of the spectroscopic grating, τ represents the wavelength of the infrared light source emitted by the lens, and d represents the grating period of the spectroscopic grating.

7. A strawberry maturity detection method based on a spectrophotometer according to claim 4, characterized in that, The calculation expression for determining the distance between the lens and the beam splitter grating is specifically as follows: In the above formula, V represents the distance between the lens and the spectrometer, W g represents the effective width of the spectroscopic grating, f represents the focal length of the lens, θ represents the field of view of the lens, and ω represents the length of the effective area of ​​the sensor.

8. A strawberry maturity detection method based on a spectrophotometer according to claim 4, characterized in that, The calculation expression for determining the distance between the spectroscopic grating and the sensor is specifically as follows: In the above formula, V represents the distance between the lens and the spectroscopic grating, f represents the focal length of the lens, θ1 represents the maximum dispersion angle of the spectroscopic grating, τ represents the wavelength of the infrared light source emitted by the 3D-TOF infrared camera, and l represents the distance between the spectroscopic grating and the sensor.

9. A strawberry maturity detection method based on a spectrophotometer according to claim 4, characterized in that, The calculation expression for determining the offset of the imaging point on the sensor is specifically as follows: In the above formula, Δx represents the offset of the imaging point on the sensor, ω represents the length of the effective area of ​​the sensor, and θ represents the field of view of the lens.

10. A strawberry maturity detection system based on a spectrophotometer, characterized in that: Includes the following modules: The first module is used to build a strawberry maturity detection device based on a spectral illuminance sensor; The second module is used to determine the target strawberry position according to the distance information obtained by the 3D-TOF infrared camera, and then the strawberry maturity detection device is adaptively adjusted and processed and the target strawberry is photographed to obtain the infrared spectrum curve graph of the target strawberry; The third module is used to determine the maturity of the target strawberry based on the infrared spectrum curve of the target strawberry.

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