Coffee granule measurement device and method

Abstract

A coffee granule measurement device and method. The measurement device (10) comprises an accommodating space (11) for accommodating coffee granules, a condensation surface (12), a cooling module (13), a first temperature measurement module (14), a dew point measurement module (15), and a calculation module (16). The cooling module (13) is used for cooling the condensation surface (12) so that water vapor of the coffee granules condenses on the condensation surface to form dew. The dew point measurement module (15) is used for detecting whether dew occurs on the condensation surface (12). The first temperature measurement module (14) is used for measuring the temperature of at least one position on the condensation surface (12). The calculation module (16) is used for: determining a first moment, the first moment being the moment when dew is detected to occur on the condensation surface (12); determining a dew point temperature on the basis of the first moment and the temperature of the at least one position; acquiring a first vapor pressure on the basis of the dew point temperature; acquiring the temperature of the accommodating space (11) and the temperature of the coffee granules; acquiring a second vapor pressure on the basis of the temperature of the accommodating space (11) and the temperature of the coffee granules; and calculating the water activity of the coffee granules on the basis of the first vapor pressure and the second vapor pressure.

Description

Coffee particle detection device and method Technical Field

[0001] The present application relates to the field of coffee measurement, and in particular to a coffee particle detection device and method. Background Art

[0002] Water activity (also known as water activity or H2O) refers to the ratio of the equilibrium vapor pressure of a food in a confined space to the saturated vapor pressure of pure water at the same temperature. Water activity values ​​range from 0 to 1. The closer a coffee bean's water activity is to 1, the more water available for microbial use, making it more susceptible to mold, bacteria, and other infections, which can reduce its quality and flavor. Maintaining a water activity between 0.4 and 0.6 for green coffee beans is generally recommended to ensure their preservation and protection from microbial contamination. A water activity above 0.6 indicates that microorganisms have more free water available, potentially leading to mold or fungal infection. A water activity below 0.4 indicates that the beans were over-dried during processing, or that the environment in which they were transported or stored was too dry, affecting their flavor and subsequent roasting.

[0003] Existing measurements of water activity in coffee beans typically use electronic hygrometers, which utilize resistor or capacitor sensors to measure relative humidity. The sensor detects changes in capacitance or resistance, converting the electrical signal into a humidity signal to produce an equilibrium relative humidity value. When the sample temperature matches the sensor temperature, the equilibrium relative humidity is equivalent to the sample water activity. This indirect method requires regular calibration due to the indirect nature of the measurement, and the definitions of capacitance and resistance are unrelated to humidity. This indirect technique requires calibration to correlate capacitance changes with humidity changes. Because humidity is only one of many factors in measuring capacitance and resistance, these can be affected by factors such as condensation, aging, and exposure to certain chemicals. Furthermore, the measurement requires full equilibrium in the sensor, a process that typically takes between 30 minutes and an hour for the final value to stabilize.

[0004] There is still room for improvement in the current measuring devices for measuring the water activity of coffee beans.

[0005] Summary of the Invention

[0006] The present application provides a coffee particle detection device and method, which can quickly and accurately measure the water activity of coffee particles.

[0007] In a first aspect, the present application provides a coffee particle detection device, comprising a accommodating space, a condensation surface, a cooling module, a first temperature detection module, a dew point detection module and a calculation module; the accommodating space is used to accommodate coffee particles; an air channel is connected between the condensation surface and the accommodating space; the cooling module is used to cool the condensation surface so that the water vapor in the coffee particles condenses into dew on the condensation surface; the dew point detection module is used to detect whether dew appears on the condensation surface; the first temperature detection module is used to detect the temperature of at least one place on the condensation surface; the calculation module is used to: determine a first moment, which is the moment when the dew appears on the condensation surface; determine the dew point temperature based on the first moment and the temperature of the at least one place; obtain a first vapor pressure based on the dew point temperature; obtain the temperature of the accommodating space and the coffee particles; obtain a second vapor pressure based on the temperature of the accommodating space and the coffee particles; and calculate the water activity of the coffee particles based on the first vapor pressure and the second vapor pressure.

[0008] Optionally, the cooling module includes a refrigeration component and a control component. The control component is configured to control the refrigeration component to cool the condensation surface to a first temperature at maximum power in a first phase, and to control the refrigeration component to cool the condensation surface at dynamic power in a second phase, such that the condensation surface cools from the first temperature to the dew point temperature at a constant rate; wherein the rate of cooling of the condensation surface in the second phase is lower than the rate of cooling in the first phase. Optionally, the device pre-stores first temperatures corresponding to different types of coffee particles; the control component is further configured to obtain the type of the coffee particles and determine the value of the first temperature based on the type of the coffee particles. Optionally, the device also pre-stores a correspondence between different types of coffee particles or different moisture contents and water activity ranges; the control component is further configured to obtain the type of the coffee particles or the moisture content of the coffee particles, determine the water activity range corresponding to the coffee particles based on the type of the coffee particles or the moisture content of the coffee particles, and control the refrigeration component to continue cooling the coffee particles if the water activity is not within the water activity range corresponding to the coffee particles.

[0009] Optionally, the device also includes a first imaging module, which includes at least two light sources with different spectra, and is used to sequentially emit light beams of different spectra to the coffee particles in the accommodating space; the first imaging module also includes a photosensitive array for sequentially receiving the reflected light of the coffee particles on the at least two light beams with different spectra and sequentially imaging the coffee particles, wherein the photosensitive array is used to generate at least two frames of images corresponding to the at least two light sources respectively; the calculation module is also used to calculate the chromaticity value of the coffee particles based on the at least two frames of images; the control component is also used to obtain the category of the coffee particles based on the imaging of the coffee particles.

[0010] Optionally, the device also pre-stores a correspondence between different moisture contents and categories of coffee particles; the control component is further used to obtain the moisture content of the coffee particles and determine the category of the coffee particles based on the moisture content.

[0011] Optionally, the cooling component is located on one side of the condensation surface, and the device further includes a heat sink located on the side of the cooling component facing away from the condensation surface and arranged adjacent to the cooling component, and a heat sink fan arranged adjacent to the heat sink.

[0012] Optionally, the device further includes a circulation fan located on one side of the condensation surface and a motor for driving the circulation fan, wherein the circulation fan is used to increase the air circulation speed between the accommodating space and the condensation surface.

[0013] Optionally, the dew point detection module is also used to detect the condensation position on the condensation surface; the first temperature detection module is used to obtain the temperatures of at least two locations on the condensation surface; the calculation module is used to obtain the distances between the positions of the at least two locations and the condensation positions, determine the weights corresponding to the at least two locations based on the distances between the positions of the at least two locations and the condensation positions, and calculate the dew point temperature based on the temperatures of the at least two locations and the weights corresponding to the at least two locations.

[0014] Optionally, the dew point detection module includes a second imaging module for acquiring images of the dew condensation surface at different times; the calculation module is further configured to detect whether a dew point appears on the dew condensation surface and / or the location of the dew on the dew condensation surface based on the grayscale values ​​of the images at different times. Optionally, the calculation module is configured to acquire the average grayscale value of the images of the dew condensation surface at different times, as well as the grayscale value distribution of different sub-areas of the images of the dew condensation surface at different times, to determine whether a dew point appears on the dew condensation surface.

[0015] Optionally, the dew point detection module includes a second imaging module for obtaining images of the condensation surface at different times; the calculation module is also used to obtain an initial image of the condensation surface containing dew, and to perform edge detection or texture feature detection on the dew in the initial image; when it is confirmed that the edge smoothness of the dew is greater than a preset threshold or the texture feature of the dew meets the requirements, the dew in the initial image is confirmed to be the dew.

[0016] Optionally, the dew point detection module includes a laser emitter and a laser detector; the laser beam emitted by the laser emitter covers the condensation surface, and the laser detector is used to receive the laser beam reflected by the condensation surface, and generate an electrical signal based on the received laser beam; the calculation module is also used to confirm the appearance of dew on the condensation surface based on changes in the electrical signal.

[0017] Optionally, the first temperature detection module includes a platinum resistance sensor located on one side of the condensation surface, and the calculation module is used to obtain the lag time of the platinum resistance sensor, and calculate the dew point temperature based on the temperature measured by the platinum resistance sensor during the lag time after the first moment.

[0018] Optionally, the second vapor pressure is calculated based on the equilibrium temperature measured when the temperature of the accommodating space and the coffee particles reach equilibrium; the calculation module pre-stores a first relationship model between the water activity measured at an equilibrium temperature of 25 degrees Celsius and the water activity measured at other equilibrium temperatures; the calculation module is also used to calculate the water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius based on the equilibrium temperature, the water activity and the first relationship model.

[0019] Optionally, the second vapor pressure is calculated based on the temperature when the temperatures of the accommodating space and the coffee particles have not reached equilibrium; the calculation module pre-stores a second relationship model between the water activity measured at an equilibrium temperature of 25 degrees Celsius and the water activity measured at other non-equilibrium temperatures; the calculation module is also used to calculate the water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius based on the temperatures of the accommodating space and the coffee particles, the water activity and the second relationship model.

[0020] Optionally, the device is further used to obtain at least one of the following parameters of the coffee particles: moisture content, density, porosity, diameter, area, color, circularity, color uniformity, texture, and chroma.

[0021] Optionally, the device includes an upper cover structure and a main body structure that are movably connected, the device also includes a detachable inner liner located in the main body structure, the accommodating space is located in the detachable inner liner, and the device also includes: a chassis structure, a first electrode and a second electrode, on the surface of which are provided with a first electrode contact and a second electrode contact, fixed to the main body structure; the first electrode and the second electrode are fixed on the chassis structure and are connected to the first electrode contact and the second electrode contact, respectively; when the detachable inner liner is combined into the main body structure, the accommodating space is embedded between the first electrode and the second electrode to change the capacitance value between the first electrode and the second electrode; the calculation module is also used to calculate the moisture content of the coffee particles based on the capacitance value between the first electrode and the second electrode.

[0022] Optionally, the first electrode is located on the chassis structure, and the second electrode is in a ring shape surrounding the first electrode, so that an annular hollow cavity is formed between the first electrode and the second electrode; at least a portion of the removable inner liner is made of a non-conductive material, and a groove extending toward the accommodating space is formed on the bottom surface of the removable inner liner, and the accommodating space is in a ring shape surrounding the groove, so that when the removable inner liner is fixed to the main structure, the accommodating space in the removable inner liner is embedded in the annular hollow cavity, and the first electrode is embedded in the groove from the outside of the bottom surface of the removable inner liner. Optionally, the removable inner liner includes an annular wall made of oxidized metal, and the bottom surface and the groove are made of a non-conductive material. Optionally, a base is provided on the chassis structure at the bottom of the first electrode, the first electrode contact is provided on the base, and the first electrode is fixed on the base and connected to the first electrode contact, so that the bottom of the first electrode is higher than the bottom of the second electrode.

[0023] Optionally, the device includes an upper cover structure and a main body structure that are movably connected, and the device includes a chassis structure located within the main body structure and having a first electrode contact and a second electrode contact disposed on its surface; the removable inner liner comprises a portion of the first electrode and a portion of the second electrode, and when the removable inner liner is assembled with the main body structure, the first electrode contacts the first electrode contact, the second electrode contacts the second electrode contact, and the accommodating space is located between the first electrode and the second electrode; the calculation module is further configured to calculate the moisture content of the coffee particles based on the capacitance between the first electrode and the second electrode. Optionally, the device further includes a detection circuit located within the main body structure, the detection circuit comprising a measured loop and a reference loop, the first electrode contact and the second electrode contact being located within the measured loop, and a reference capacitor having a known capacitance value disposed within the reference loop; the calculation module is configured to obtain a capacitance difference between the capacitance between the first electrode and the second electrode detected by the detection circuit and the capacitance of the reference capacitor; the calculation module is further configured to calculate the moisture content of the coffee particles based on a pre-stored relationship model between the capacitance difference and moisture content and the obtained capacitance difference. Optionally, the detection circuit is further used to obtain at least two capacitance values ​​corresponding to at least two different electrode frequencies between the first electrode and the second electrode; the calculation module is further used to calculate at least two moisture contents corresponding to the at least two capacitance values, and to perform weighted calculation of the at least two moisture contents to obtain the moisture content of the coffee particles.

[0024] Optionally, the condensation surface, the cooling module, the first temperature detection module and the dew point detection module are located in the upper cover structure; a third imaging module is further provided in the upper cover structure for imaging the coffee particles in the accommodating space; a preset correction model is also pre-stored in the device for indicating the relationship between the moisture content and at least the gap ratio; the calculation module is further used to obtain the gap ratio of the coffee particles based on the imaging, and to correct the moisture content based on the gap ratio and the preset correction model. Optionally, the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; the device further includes a second temperature detection module for detecting the temperature of the coffee particles; the calculation module is used to correct the moisture content based on the temperature of the coffee particles detected by the second temperature detection module, the gap ratio and the preset correction model.

[0025] Optionally, the device further includes a pressure sensor located beneath the chassis structure within the main structure, configured to detect the weight of the coffee particles within the removable inner container; the calculation module is further configured to calculate the volume of the coffee particles based on the gap ratio and the volume of the removable inner container, and to calculate the density of the coffee particles based on the weight and volume of the coffee particles detected by the pressure sensor. Optionally, the preset correction model is a relationship model between the moisture content and at least the gap ratio and the density; the calculation module is configured to correct the moisture content based on the gap ratio, the density, and the preset correction model.

[0026] Optionally, the device is also preset with a relationship model between the diameter and gap ratio, density and moisture content of coffee particles, and the calculation module is further used to calculate the diameter of the coffee particles based on the relationship model, the gap ratio, the density and the moisture content; the device also includes a user interface for displaying the diameter of the coffee particles to the user.

[0027] Optionally, the calculation module is further configured to classify the coffee particles into one of a plurality of preset grades based on at least one of the following parameters: color, texture, diameter, area, circularity, color uniformity, and chroma; and the user interface is further configured to display the grade of the coffee particles to the user. Optionally, the calculation module is further configured to pre-store or query in real time guidance for at least one of the following: storage, roasting, grinding, and brewing of coffee beans of different grades; and the user interface is further configured to display the guidance corresponding to the grade of the coffee particles. Optionally, the calculation module also pre-stores a prediction model and, based on the at least one parameter of the coffee beans and the prediction model, infers a pre-treatment method and / or pre-treatment time for the coffee particles; and the user interface is further configured to display the pre-treatment method and / or pre-treatment time to the user. Optionally, the calculation module is further configured to: obtain a pre-stored initial moisture content of the removable inner container; obtain a current moisture content of the removable inner container when it is empty; and correct the moisture content of the coffee particles based on the difference between the current moisture content and the initial moisture content.

[0028] Optionally, the device includes an upper cover structure and a main body structure that are movably connected, the accommodating space being located within the main body structure; the upper cover structure includes a concave cavity, which is in communication with the accommodating space when the upper cover structure covers the main body structure; the concave cavity is provided with a first platform at a first depth, and the condensation surface is located on the first platform; the first imaging module is located within the upper cover structure, and the at least two light sources with different spectrums are located at a second depth of the concave cavity, the second depth being further away from the accommodating space than the first depth. Optionally, the photosensitive array is located at a third depth of the concave cavity; the upper cover structure is further provided with infrared anti-reflection glass located between the first and third depths of the concave cavity to block the air passage between the first imaging module and the accommodating space; or at least one reflector is further provided within the upper cover structure or the main body structure, and the second imaging module is configured to receive light reflected by the coffee particles from the at least two light beams with different spectrums through the at least one reflector to image the coffee particles.

[0029] Optionally, the device includes an upper cover structure and a main body structure that are movably connected. The device also includes a removable inner liner located within the main body structure. The storage space is located within the removable inner liner. The bottom of the removable inner liner is infrared anti-reflective glass, and the first imaging module is located below the bottom of the removable inner liner. Optionally, the device also includes a temperature and humidity sensor for detecting the temperature and humidity of the environment in which the coffee beans are located; the device also includes an air pressure sensor for detecting the air pressure of the environment in which the coffee beans are located; the calculation module is further configured to calculate altitude data based on the air pressure; and the user interface is further configured to display the temperature and humidity, air pressure, and altitude data as coffee bean picking environment data.

[0030] The device also includes a calibration kit, which includes at least one of the following: a calibration liner, a calibration color card, a water activity standard liquid, and a standard liquid carrying container; the calculation module is also used to perform at least one of the following: compensating the moisture content measurement result of the coffee particles based on the moisture content measurement result of the calibration liner; compensating the colorimetry measurement result of the coffee particles based on the colorimetry measurement result of the calibration color card; and compensating the water activity measurement result of the coffee particles based on the measurement result of the water activity standard liquid in the standard liquid carrying container.

[0031] In a second aspect, the present application provides a method for detecting coffee particles, comprising: cooling a condensation surface having an air passage connected to a accommodating space, the accommodating space being used to accommodate coffee particles, so that water vapor in the coffee particles condenses into dew on the condensation surface; detecting whether the dew appears on the condensation surface; determining a first moment, the first moment being the moment when the dew point appears on the condensation surface; detecting the temperature of at least one location on the condensation surface, and determining the dew point temperature based on the temperature of the at least one location at the first moment; obtaining a first vapor pressure based on the dew point temperature; obtaining the temperature of the accommodating space and the coffee particles; obtaining a second vapor pressure based on the temperature of the accommodating space and the coffee particles, and calculating the water activity of the coffee particles based on the first vapor pressure and the second vapor pressure.

[0032] Optionally, the cooling of the condensation surface having an air passage connected to the accommodating space includes: in a first stage, controlling the refrigeration component at maximum power to cool the condensation surface to a first temperature; in a second stage, controlling the refrigeration component at dynamic power to cool the condensation surface, so that the condensation surface is cooled from the first temperature to the dew point temperature at a constant cooling rate; wherein, the cooling rate of the condensation surface in the second stage is lower than the cooling rate in the first stage.

[0033] Optionally, controlling the refrigeration component to cool the condensation surface to a first temperature at a first power also includes obtaining the category of the coffee particles; and determining the value of the first temperature according to the category of the coffee particles.

[0034] Optionally, the method further includes: obtaining the category of the coffee particles or the correspondence between different moisture contents and water activity ranges; obtaining the category of the coffee particles or the different moisture contents; confirming the water activity range corresponding to the coffee particles based on the category of the coffee particles or the different moisture contents and the correspondence; when the water activity is not within the water activity range corresponding to the coffee particles, controlling the refrigeration component to continue cooling.

[0035] Optionally, obtaining the category of the coffee particles includes: providing the user with options of different categories of coffee particles through an interactive interface; and determining the category of the coffee particles based on the option selected by the user. Optionally, the method further includes: emitting at least two light beams of different spectra toward the coffee particles in the accommodating space; receiving reflected light of the at least two light beams of different spectra from the coffee particles and imaging the coffee particles; and calculating the chromaticity value of the coffee particles based on the imaging of the coffee particles. Obtaining the category of the coffee particles includes: obtaining the category of the coffee particles based on the imaging of the coffee particles. Optionally, obtaining the category of the coffee particles includes: obtaining the moisture content of the coffee particles; and determining the category of the coffee particles based on the moisture content and a pre-stored correspondence between different moisture contents and categories of coffee particles.

[0036] Optionally, the detecting whether dew appears on the dew condensation surface includes: detecting whether dew points appear on the dew condensation surface and / or the position of the dew on the dew condensation surface based on the grayscale values ​​of the images at different moments. Optionally, the detecting whether dew points appear on the dew condensation surface based on the grayscale values ​​of the images at different moments includes: obtaining the grayscale value mean of the images of the dew condensation surface at different moments, and / or the grayscale value distribution of different subareas of the images of the dew condensation surface at different moments; and determining whether dew points appear on the dew condensation surface based on the grayscale value mean and / or the grayscale value distribution.

[0037] Optionally, the method further includes: obtaining an initial image of the dew condensation surface containing dew, and performing edge detection or texture feature detection on the dew in the initial image; when it is confirmed that the edge smoothness of the dew is greater than a preset threshold or the texture feature of the dew meets the requirements, confirming that the dew in the initial image is the dew. Optionally, detecting whether the dew is present on the dew condensation surface includes: emitting a laser beam from a laser emitter to cover the dew condensation surface; receiving the laser beam reflected by the dew condensation surface by a laser detector; generating an electrical signal based on the received laser beam; and confirming the presence of dew on the dew condensation surface based on changes in the electrical signal.

[0038] Optionally, detecting the temperature of at least one location on the condensation surface and determining the dew point temperature based on the temperature of at least one location at a first moment include: detecting the temperature through a platinum resistance sensor located on one side of the condensation surface; obtaining the lag time of the platinum resistance sensor; and calculating the dew point temperature based on the temperature measured by the platinum resistance sensor during the lag time after the first moment.

[0039] Optionally, the second vapor pressure is calculated based on an equilibrium temperature measured when the temperatures of the accommodating space and the coffee particles reach equilibrium; the method further includes: obtaining a pre-stored first relationship model between water activity measured at an equilibrium temperature of 25 degrees Celsius and water activity measured at other equilibrium temperatures; and calculating the water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius based on the equilibrium temperature, the water activity, and the first relationship model. Optionally, the second vapor pressure is calculated based on a temperature when the temperatures of the accommodating space and the coffee particles do not reach equilibrium; the method further includes: obtaining a pre-stored second relationship model between water activity measured at an equilibrium temperature of 25 degrees Celsius and water activity measured at other non-equilibrium temperatures; and calculating the water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius based on the temperatures of the accommodating space and the coffee particles, the water activity, and the second relationship model.

[0040] Optionally, the method further comprises: obtaining at least one of the following parameters of the coffee particles: moisture content, density, porosity, diameter, area, color, circularity, color uniformity, texture, and chroma.

[0041] Optionally, the method further includes: placing the accommodating space between a first electrode and a second electrode to change the capacitance value between the first electrode and the second electrode; detecting the capacitance value between the first electrode and the second electrode by a detection circuit; and calculating the moisture content of the coffee particles based on the capacitance value between the first electrode and the second electrode. Optionally, the detection circuit includes a measured loop and a reference loop, and a reference capacitor with a known capacitance value is provided on the reference loop. The method further includes obtaining a capacitance difference between the capacitance value between the first electrode and the second electrode detected by the detection circuit and the capacitance value of the reference capacitor; calculating the moisture content of the coffee particles based on the capacitance value between the first electrode and the second electrode includes: calculating the moisture content of the coffee particles based on a pre-stored relationship model between the capacitance difference and the moisture content, and the obtained capacitance difference. Optionally, detecting the capacitance value between the first electrode and the second electrode by a detection circuit includes: obtaining at least two capacitance values ​​between the first electrode and the second electrode corresponding to at least two different electrode frequencies; calculating the moisture content of the coffee particles based on the capacitance value between the first electrode and the second electrode includes: calculating at least two moisture contents corresponding to the at least two capacitance values, and performing weighted calculation of the at least two moisture contents to obtain the moisture content of the coffee particles.

[0042] Optionally, the method further includes: obtaining a pre-stored preset calibration model, wherein the preset calibration model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; imaging the coffee particles in the accommodating space;

[0043] The gap ratio of the coffee particles is obtained according to the imaging; and the moisture content is corrected according to the gap ratio and the preset correction model.

[0044] Optionally, the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; the method further includes: detecting the temperature of the coffee particles; and correcting the moisture content based on the detected temperature of the coffee particles, the gap ratio, and the preset correction model. Optionally, the method further includes: detecting the weight of the coffee particles using a pressure sensor; calculating the volume of the coffee particles based on the gap ratio and the volume of the accommodating space; and calculating the density of the coffee particles based on the weight of the coffee particles detected by the pressure sensor and the volume of the coffee particles. Optionally, the preset correction model is a relationship model between the gap ratio, the density, and the moisture content; and correcting the moisture content based on the gap ratio and the preset correction model includes: correcting the moisture content based on the gap ratio, the density, and the preset correction model.

[0045] Optionally, the method further includes: obtaining a pre-stored relationship model between the diameter and gap ratio, density and moisture content of coffee particles; calculating the diameter of the coffee particles based on the relationship model, the gap ratio, the density and the moisture content; and displaying the diameter of the coffee particles to the user through a user interface.

[0046] Optionally, the method further comprises: classifying the coffee particles into one of a plurality of preset grades according to at least one of the following parameters: color, texture, diameter, area, roundness, color uniformity, chroma; and displaying the grade of the coffee particles to the user via a user interface.

[0047] Optionally, the method further includes: obtaining pre-stored or real-time guidance suggestions for at least one of storage, roasting, grinding, and brewing of coffee beans of different grades; and displaying the guidance suggestions corresponding to the grade of the coffee particles via the user interface. Optionally, the method further includes: obtaining a pre-stored inference model; inferring a pretreatment method and / or pretreatment time for the coffee particles based on the at least one parameter of the coffee beans and the inference model; and displaying the pretreatment method and / or pretreatment time to the user via the user interface.

[0048] Optionally, the method further includes: obtaining a pre-stored initial moisture content of the removable inner container; obtaining a current moisture content of the removable inner container when empty; and correcting the moisture content of the coffee particles based on the difference between the current moisture content and the initial moisture content. Optionally, the method further includes: detecting the temperature and humidity of the environment in which the coffee beans are located using a humidity sensor; detecting the air pressure of the environment in which the coffee beans are located using a pressure sensor; calculating altitude data based on the air pressure; and displaying the temperature, humidity, air pressure, and altitude data as coffee bean picking environment data via a user interface.

[0049] The method further includes at least one of the following steps: compensating the moisture content measurement result of the coffee particles based on the moisture content measurement result of the calibration inner tank; compensating the colorimetry measurement result of the coffee particles based on the colorimetry measurement result of the calibration color card; and compensating the water activity measurement result of the coffee particles based on the measurement result of the water activity standard liquid in the standard liquid holding container.

[0050] In this embodiment, since water activity (AW) is the ratio of the actual water vapor pressure P0 to the saturated water vapor pressure P1 at the same temperature, while maintaining constant air pressure, the cooling module in this embodiment rapidly cools the condensation surface until the air reaches the saturation temperature. When the saturation temperature is reached, water vapor precipitates on the condensation surface. By detecting the first moment of condensation on the condensation surface and then obtaining the dew point temperature using the first temperature detection module, the actual water vapor pressure P0 can be calculated. The saturated vapor pressure P1 is then calculated using the coffee particle temperature and the cavity temperature. The ratio of the two is the water activity. This measurement structure and method can quickly and accurately measure the water activity of coffee particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a schematic diagram of the logical framework of an embodiment of a coffee particle detection device of the present application; Figures 2 and 3 are schematic diagrams of the structure of the coffee particle detection device of an embodiment of the present application in two different states respectively; Figure 4 is a perspective view of the internal structure of the coffee particle detection device of the embodiment shown in Figure 2; Figure 5 is a schematic diagram of the partial structure inside the upper cover structure of the coffee particle detection device shown in Figure 4; Figure 6 is a schematic diagram of the relationship between the voltage of the laser detector and the temperature of the condensation surface in an embodiment of the present application; Figure 7 is a schematic diagram of the positional relationship between the condensation surface, the cooling module, the first temperature detection module and the dew point detection module in an embodiment of the present application; Figure 8 is a comparison diagram of the results of measuring the temperature of the same condensation surface by an RTD sensor and a thermistor at different times in an embodiment of the present application; Figure 9 is a schematic diagram of the temperature detection points and condensation positions on the condensation surface in an embodiment of the present application; Figure 10 is an exploded schematic diagram of the chassis structure, electrode structure and detachable inner tank of the coffee particle detection device of an embodiment of the present application; Figure 11 is a schematic diagram of the chassis structure shown in Figure 10 and an assembly relationship diagram of the electrode structure; Figure 12a is a bottom side view of the detachable inner liner shown in Figure 9; Figure 12b is a structural schematic diagram of the chassis structure and the first electrode of the coffee particle detection device of an embodiment of the present application; Figure 13 is an exploded schematic diagram of the chassis structure and the detachable inner liner of the coffee particle detection device of an embodiment of the present application; Figure 14 is a schematic diagram of the assembly relationship of the chassis structure and the detachable inner liner shown in Figure 13; Figure 15 is a schematic diagram of an image of coffee particles located in the detachable inner liner in an example; Figure 16 is an overhead view of the upper cover structure of the coffee particle detection device in an embodiment of the present application; Figure 17 is a schematic diagram of the positional relationship between the photosensitive array, coffee particles and the reflector in an embodiment of the coffee particle detection device of the present application; Figure 18a is a schematic diagram of the positional relationship between the detachable inner liner and the first imaging module in the coffee particle device in an embodiment of the present application; Figure 18b is a structural schematic diagram of the self-calibration kit in an embodiment of the present application; Figure 19 is a flow chart of an embodiment of the coffee particle detection method of the present application. DETAILED DESCRIPTION

[0052] The following describes embodiments of the present application in more detail with reference to the accompanying drawings. While embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to make this application more thorough and complete and to fully convey the scope of this application to those skilled in the art. The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this application and the appended claims, the singular forms "a," "the," and "an" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It should be understood that although the terms "first," "second," "third," etc. may be used in this application to describe various information, such information should not be limited to these terms. These terms are used solely to distinguish information of the same type from one another. For example, first information could be referred to as second information, and similarly, second information could be referred to as first information without departing from the scope of this application. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise clearly defined.

[0053] As shown in Figure 1, Figure 1 is a logical framework diagram of an embodiment of the coffee particle detection device of the present application. The coffee particle water activity detection device 10 includes a accommodating space 11, a condensation surface 12, a cooling module 13, a first temperature detection module 14, a dew point detection module 15 and a calculation module 16. The accommodating space 11 is used to accommodate coffee particles. An air passage is connected between the condensation surface 12 and the accommodating space. The cooling module 13 is used to cool the condensation surface 121 so that the water vapor in the coffee particles condenses on the condensation surface 121 to precipitate dew. There are various positional relationships between the condensation surface 12 and the accommodating space 11. For example, the condensation surface 12 is located on one side of the accommodating space 11, or the condensation surface 12 is located inside the accommodating space 11. Regardless of the positional relationship, an air passage is connected between the condensation surface of condensation surface 12 and the accommodating space 11, allowing water vapor from the coffee particles in the accommodating space to precipitate and form dew on the condensation surface when the temperature of the condensation surface decreases, thereby detecting the dew point temperature of the coffee particles. There are many types of coffee particles. For example, the coffee particles in this application can refer to any of green coffee beans, roasted coffee beans, shelled coffee beans, dried coffee berries, and coffee powder.

[0054] The dew point detection module 15 is configured to detect whether dew has appeared on the dew condensation surface 12. The first temperature detection module 14 is configured to detect the temperature of at least one location on the dew condensation surface. The calculation module 16 is configured to determine a first moment, which is the moment when dew is detected on the dew condensation surface; determine a dew point temperature based on the first moment and the temperature of the at least one location; obtain a first vapor pressure based on the dew point temperature; obtain the temperature of the accommodating space and the coffee particles; obtain a second vapor pressure based on the temperature of the accommodating space and the coffee particles; and calculate the water activity of the coffee particles based on the first vapor pressure and the second vapor pressure. Since the measurement of water activity (AW) is the ratio of the actual water vapor pressure P0 to the saturated water vapor pressure P1 at the same temperature, that is, AW = P0 / P1, the condensation surface is cooled by the cooling module in the embodiment of the present application while keeping the air pressure unchanged, so that the air is cooled to the saturation temperature; when the saturation temperature is reached, water vapor will precipitate on the condensation surface, and the actual water vapor pressure P0 can be calculated by detecting the first moment when condensation appears on the condensation surface and then obtaining the temperature at the time of condensation through the first temperature detection module to obtain the dew point temperature. The saturated vapor pressure P1 is then calculated by the equilibrium temperature, and the ratio of the two is the water activity. Optionally, the temperature balance refers to the overall temperature (including the cavity temperature and the temperature of the coffee particles) reaching equilibrium.

[0055] Optionally, the coffee particle detection device also includes a second temperature detection module for monitoring the cavity temperature and the temperature of the coffee particles to provide temperature information in multiple dimensions. In one example, the second temperature detection module includes an infrared temperature sensor, which is located on one side of the accommodating space. The temperature of the coffee particles in the accommodating space can be measured by infrared temperature measurement, and the temperature of the environment in which it is located, that is, the cavity temperature, can be output to the calculation module to determine whether the temperature balance is reached. Optionally, the second temperature detection module also includes a temperature and humidity sensor for detecting the temperature and humidity in the cavity, which can provide more environmental information for the calculation of the calculation module and improve the accuracy of the calculation results. Optionally, the coffee particle detection device also includes a circulation fan and a motor for driving the circulation fan, and the circulation fan is used to increase the air circulation speed in the accommodating space, accelerate the cavity temperature and the temperature of the coffee particles to reach equilibrium, so that the equilibrium temperature can be measured as soon as possible.

[0056] When measuring water activity, the standard stipulates that the saturated vapor pressure at the equilibrium temperature needs to be measured at 25 degrees Celsius. At other equilibrium temperatures, the water activity will have a certain error. Optionally, the coffee particle detection device in some examples also pre-stores a first relationship model between the water activity measured at an equilibrium temperature of 25 degrees Celsius and the water activity measured at other equilibrium temperatures. In this way, there is no need to wait until the stable temperature reaches 25 degrees Celsius. The calculation module can calculate the vapor pressure P1 when other equilibrium temperatures are obtained, and when the water activity WA_0 is calculated based on P1 and P0, the water activity corresponding to the equilibrium temperature of 25 degrees Celsius is calculated based on the water activity WA_0 corresponding to the other equilibrium temperature and the first relationship model. This can improve the measurement speed while ensuring the accuracy of the measurement results. In one example, the first relationship model is WA=WA_0+a*(T1-25), where WA_0 is the water activity measured under the equilibrium temperature T1, a is a fixed constant that can be obtained through experiments, and a*(T-25) is the compensation value of the equilibrium temperature T1 for the standard water activity at 25 degrees Celsius. The calculated WA is the compensated standard water activity.

[0057] Alternatively, in some examples, the calculation module can calculate vapor pressure P1 based on the currently measured temperature T2, rather than waiting for temperature equilibrium to be reached. The coffee particle detection device also pre-stores a second relationship model between water activity measured at an equilibrium temperature of 25 degrees Celsius and water activity measured at other non-equilibrium temperatures. The calculation module calculates vapor pressure P2 based on the currently measured temperature T2, and after calculating water activity WA_1 based on P2 and P0, it also calculates the water activity corresponding to an equilibrium temperature of 25 degrees Celsius based on the water activity WA_1 corresponding to temperature T2 and the second relationship model. This ensures measurement accuracy while improving measurement speed. In one example, AW = AW_ub + b*(T2-T1), where b is a fixed constant that can be obtained through experiments, T1 is the temperature of the coffee particles, T2 is the cavity temperature, AW_ub is the water activity of the coffee particles obtained using the cavity temperature T2 as the equilibrium temperature, and AW is the water activity compensated by the difference between the cavity temperature and the temperature of the coffee particles.

[0058] There are many ways for the cooling module to cool the condensation surface. In one example, the cooling module includes a refrigeration component and a control component. The refrigeration component is in contact with the condensation surface, and the control component is used to control the cooling of the refrigeration component to drive the cooling of the condensation surface. Optionally, the control component is used to control the refrigeration component to cool the condensation surface to a first temperature at a first power in the first stage, and the first temperature is higher than the dew point temperature. Then, the control component controls the refrigeration component to cool the condensation surface at a dynamic power in the second stage, so that the condensation surface is cooled from the first temperature to the dew point temperature at a constant cooling rate, and the cooling rate of the condensation surface in the second stage is lower than the cooling rate in the first stage. Optionally, the first power is the maximum power of the control component, so that the refrigeration component cools the condensation surface from the current temperature to the first temperature at the fastest speed in the first stage. In the first stage, the cooling rate of the condensation surface may not be fixed. When the control component is controlled at maximum power, the condensation surface will most likely cool down in a nonlinear manner. The second-stage control component controls the temperature of the condensation surface to cool linearly, enabling the cooling rate to match the resolution of the collected temperature. This allows the calculation module to more accurately determine the temperature at the time of condensation from the temperatures monitored at different times by the first temperature detection module. Optionally, the control power of the second-stage control component can be reversely controlled based on the real-time measured temperature changes. Specifically, the pulse width modulation (PWM) can be reversely controlled based on the real-time measured temperature changes to enable the temperature in the second stage to decrease linearly.

[0059] For example, in the second stage, when the control component cools the condensation surface, the measured temperature of the condensation surface is obtained in real time. When it is determined that the temperature change of the condensation surface within each preset time interval does not reach the preset temperature change, the power is increased so that the temperature change of the condensation surface within the next preset time interval reaches the preset temperature change; when it is determined that the temperature change of the condensation surface within each preset time interval exceeds the preset temperature change, the power is reduced so that the temperature change of the condensation surface within the next preset time interval drops to the preset temperature change.

[0060] Because different types of coffee particles have different dew point temperatures, the control inflection point (preset as the first temperature) set when controlling the cooling of the condensation surface can be different. Optionally, the control component is further configured to obtain the type of coffee particles and determine the value of the first temperature based on the type of the coffee particles. There are various ways to obtain the type of coffee particles. In one example, the type of coffee particles can be obtained by pre-stored mappings of multiple types and corresponding first temperatures, and by obtaining a user-selected type from multiple category options. Alternatively, in one example, the coffee particle detection device also pre-stores a correspondence between different moisture contents and coffee particle types. The control component can obtain the moisture content of the coffee particles and determine the type of the unsealed particles based on the moisture content and the correspondence. The coffee particle detection device also includes a module for detecting moisture content, details of which are described below. After obtaining the moisture content, the moisture content detection module is also configured to determine the type of coffee particles for the control component. Alternatively, in one example, the coffee particle detection device also includes a first imaging module for imaging the coffee particles. Specifically, the first imaging module includes a light source and a photosensitive array. The light source is configured to emit a light beam toward the storage space, and the photosensitive array is configured to receive the light beam reflected by the coffee particles within the storage space and to form an image. The control component identifies the coffee particle category by identifying the imaged content. In some examples, the imaging produced by the first imaging module can also enable a computing module to calculate the colorimetric value of the coffee particles. Optionally, the first imaging module includes a light source for at least two different spectra, configured to sequentially emit light beams of different spectra toward the coffee particles within the storage space, and a photosensitive array configured to sequentially receive light reflected from the coffee particles by the at least two different spectra and to sequentially form images of the coffee particles. The photosensitive array is configured to generate at least two frames of images corresponding to the at least two light sources. Optionally, the at least two frames of images are original images with an upper limit of 30 to 40 million pixels or even higher. The computing module is further configured to calculate the colorimetric value of the coffee particles based on the at least two frames of images. By fusing the images formed when the coffee particles are illuminated by light sources of different spectra, the problem of poor colorimetric value detection stability caused by using a single spectrum acquisition method can be effectively avoided.

[0061] Optionally, the coffee particle detection device also pre-stores a correspondence between different types of coffee particles or different moisture contents and water activity ranges. After the calculation module calculates the water activity, the calculation module also searches for the corresponding water activity range based on the type of coffee particles or the moisture content of the coffee particles and confirms whether the calculated water activity falls within the corresponding water activity range. If not, it indicates that an error occurred during the water activity measurement process, for example, the dew point detection module may have mistakenly detected dew. Optionally, if the calculation module confirms that the calculated water activity falls outside the corresponding water activity range, the cooling module is used to continue cooling the condensation surface to determine the true dew point temperature.

[0062] There are various structures for coffee particle detection devices, as shown in Figures 2 and 3, which are schematic diagrams of the structure of a coffee particle detection device according to one embodiment of the present application in two different states. The coffee particle detection device includes a movably connected upper cover structure 21 and a main body structure 22. A removable inner liner 23 is located within the main body structure 22. The removable inner liner 23 has an opening 231 and a space 232 for loading coffee particles. When the upper cover structure 21 covers the main body structure 22, the opening of the removable inner liner 23 is sealed. In Figure 2, the upper cover structure 21 is in an open state, allowing the user to remove the removable inner liner 23 and load coffee particles. In Figure 3, the removable inner liner 23 is detached from the main body structure 22, allowing the user to load coffee particles to be tested into the removable inner liner 23. Optionally, a condensation surface 24, a cooling module (not shown), a first temperature detection module (not shown), and a dew point detection module (not shown) are located within the upper cover structure 21. When the upper cover structure 21 covers the main structure 22, a communicating air passage is formed between the condensation surface 24 and the accommodating space 232. After the cooling module cools down the condensation surface, the water vapor in the coffee particles can condense on the condensation surface 24 to achieve condensation. As shown in Figures 4 and 5, Figure 4 is a perspective view of the internal partial structure of the coffee particle detection device of the embodiment shown in Figure 2, and Figure 5 is a schematic diagram of the partial structure inside the upper cover structure of the coffee particle detection device shown in Figure 4. The upper cover structure 21 includes a concave cavity 211. When the upper cover structure 21 covers the main structure 22, the concave cavity 211 is connected to the accommodating space. The concave cavity 211 is provided with a first platform 2111 at a first depth, and the condensation surface 24 is located on the first platform 2111.

[0063] The cooling module 25 includes a cooling assembly 251 located on one side of the condensation surface 24, a heat sink 252 located on the side of the cooling assembly 251 facing away from the condensation surface 24 and fixed to the cooling assembly 251, and a heat sink fan 253 disposed adjacent to the heat sink 252. Optionally, the coffee particle detection device further includes a circulation fan 26 located within the upper cover structure on the side of the condensation surface 24 and a motor 28 for driving the circulation fan 26.

[0064] Optionally, the dew point detection module 27 includes a laser emitter 271 and a laser detector 272 located opposite the first platform 2111, as well as a detection module (not shown) located within the upper cover structure. The laser emitter 271 is configured to emit a laser beam that covers the dew condensation surface 24. The laser detector 272 is configured to receive the laser beam reflected by the dew condensation surface 24 and generate an electrical signal based on the received laser beam. The detection module is configured to confirm the presence of a dew point on the dew condensation surface based on changes in the electrical signal. As shown in Figure 6, Figure 6 is a schematic diagram of the relationship between the voltage of the laser detector and the temperature of the dew condensation surface in one embodiment of the present application. In the figure, L1 represents the temperature of the dew condensation surface, and L2 represents the voltage of the laser detector 272. It can be seen that when the output power of the laser emitter 271 remains constant, the voltage of the laser detector 272 also remains stable. As the temperature of the dew condensation surface decreases, when condensation appears on the dew condensation surface 24, the diffuse reflection of the laser beam by the condensation causes the light energy received by the laser detector 272 to decrease, and the corresponding voltage also decreases. The detection module monitors the voltage changes of the laser detector in real time and can accurately capture the moment when condensation appears on the condensation surface, determining this moment as the first moment. The temperature of the condensation surface at the first moment is the dew point temperature.

[0065] The first temperature detection module includes at least one temperature sensor for detecting the temperature of at least one location on the dew point surface 24. As shown in Figure 7, Figure 7 is a schematic diagram of the positional relationship between the dew point surface, cooling module, first temperature detection module, and dew point detection module in one embodiment of the present application. The first temperature detection module includes at least one temperature sensor located on at least one side of the dew point surface 24. In Figure 7, a first groove 71 and a second groove 72 are provided on either side of the dew point surface 24, respectively. The first temperature detection module includes a first temperature sensor (not shown) and a second temperature sensor (not shown) located in the first groove 71 and the second groove 72, respectively. In one example, the first temperature sensor is a platinum resistance sensor (e.g., an RTD sensor), and the second temperature sensor is a thermistor. Platinum resistance sensors are devices made of platinum. Their resistance changes linearly with changes in temperature, offering the advantage of high measurement accuracy, but they have low sensitivity and the measured temperature may have hysteresis. In contrast, thermistors include thermal resistors, which are typically made of semiconductor materials. Their resistance changes nonlinearly with changes in temperature, offering high sensitivity but low measurement accuracy. In this application, it is necessary to accurately obtain the moment when the dew point temperature is detected. By combining a platinum resistance sensor and a thermistor, the measurement lag time of the platinum resistance sensor can be calculated using the temperatures measured by the thermistor and the platinum resistance sensor respectively, and then the actual measurement time of the dew point temperature can be accurately obtained based on the first moment and the lag time. Optionally, the platinum resistance sensor can adopt a four-wire platinum resistance sensor. The four-wire lead method is to connect two wires at each end of the root of the thermal resistor, where two leads provide a constant current I to the thermal resistor, converting R into a voltage signal U. This wiring method does not require the leads to have equal resistance values, and can eliminate the influence of lead resistance on temperature measurement.

[0066] As shown in Figure 8, Figure 8 is a comparison chart of the results of measuring the temperature of the same condensation surface at different times by an RTD sensor and a thermistor in one embodiment of the present application. Among them, L3 is a schematic diagram of the temperature curve of the RTD sensor, and L4 is a schematic diagram of the temperature curve of the thermistor. It can be seen from the figure that for the same measured temperature, the measured time of the RTD sensor lags behind the measured time of the thermistor. There are many ways to calculate the lag time of the RTD sensor. In one example, the condensation surface is rapidly cooled down and then heated up by a cooling module, and the lag time of the RTD sensor can be obtained by measuring the time difference of the temperature inflection points of the platinum resistance sensor and the thermistor respectively. The inflection point temperature can be a preset temperature. Alternatively, optionally, since the lag time of the platinum resistance sensor is not strictly consistent at different temperatures, the temperature inflection point is set near the dew point temperature, which can more accurately measure the lag time of the platinum resistance sensor.

[0067] Optionally, the hysteresis time of the platinum resistance sensor can be measured online. For example, the coffee particle detection device is equipped with a calibration mode, and the hysteresis time is measured by the user when the self-calibration mode is activated. Optionally, when the user activates the self-calibration mode, the user can also select the type of coffee particles to be calibrated, so that the inflection point temperature in the self-calibration mode is set to a preset temperature corresponding to that type, where the preset temperature is close to the temperature of coffee particles of that type. Alternatively, in one example, the hysteresis time can be not measured online, but rather calibrated and stored in the coffee particle detection device before shipment, and used by the calculation module to calculate the dew point temperature. In this way, the coffee particle detection device can also be equipped with a thermistor. When determining the first moment and obtaining the temperature measured by the platinum resistance sensor, the calculation module determines the dew point temperature based on the pre-stored hysteresis time. For example, the temperature of the platinum resistance sensor at the first moment after the hysteresis time is used as the dew point temperature. There are various methods and structures for detecting the condensation location and dew point temperature. In some examples, the dew point detection module can include a thermal imaging module for thermally imaging the condensation surface. The calculation module is further configured to confirm at least one of the following based on the thermal image output by the thermal imaging module: whether a dew point appears on the condensation surface, the position of the dew point on the condensation surface, and the dew point temperature.

[0068] Alternatively, in some examples, the coffee particle detection device does not include a thermal imaging module, but instead includes a second imaging module for performing conventional imaging of the condensation surface. The images output by this second imaging module are used by the computing module to determine whether condensation has occurred on the condensation surface and / or the location of the condensation on the condensation surface. For example, after obtaining multiple output images from the second imaging module, the computing module performs image recognition on each image to confirm whether condensation has occurred. In some examples, the computing module is configured to detect the presence of dew points on the condensation surface and / or the location of the dew on the condensation surface based on the grayscale values ​​of the images at different times.

[0069] For example, since the grayscale values ​​of images with condensation and without condensation are different, the calculation module distinguishes whether condensation occurs in each image by counting the grayscale value averages of the images of the condensation surface at different times. When counting the grayscale value averages, the calculation module can count the overall grayscale value average of each image, or divide the image into fixed different partitions and count the grayscale value averages of each partition in each image. By comparing the grayscale value averages of different partitions in the same image and / or the grayscale value averages of the same partition in different images, the image with condensation in the partition is identified, thereby simultaneously screening out the image with condensation and the location of the condensation in the image. Alternatively, in some examples, the calculation module can also determine the area of ​​interest from the image before counting the grayscale value, and then only count the grayscale value of the area of ​​interest. This can improve the correlation of the image area used to determine condensation, thereby improving the accuracy and efficiency of condensation position detection. Optionally, in some examples, the computing module is further used to filter out an initial image containing dew from the multiple images output by the second imaging module, and to perform edge detection on the dew on the condensation surface in the initial image. When it is confirmed that the smoothness of the edge of the dew is greater than a preset threshold, the computing module confirms that the dew in the initial image is the dew. The edge of the dew is relatively smooth, with a relatively gentle change, while the edge of the dirt will have a larger mutation. By setting a smoothness threshold to determine whether it is dew, the computing module can avoid mistakenly detecting dirt on the condensation surface as dew. There are many ways to measure the smoothness of the dew edge. For example, the degree of change of the pixel value at the dew edge can be detected. The smaller the degree of change of the pixel value, the higher the smoothness. Alternatively, the texture features at the dew edge can be obtained, and when the texture features meet the preset requirements, the dew in the initial image is confirmed to be dew.

[0070] Optionally, in some examples, the second imaging module can be combined with multiple temperature sensors to more accurately measure the temperature at the condensation location. For example, multiple temperature detection points are provided on the condensation surface, and the first temperature detection module is used to obtain the temperatures of at least two of these points. For example, a temperature sensor probe is provided at each temperature detection point, and the temperature sensor probe detects the temperature of the corresponding temperature detection point at a certain frequency. After the calculation module confirms the first moment when the dew point appears on the condensation surface, it determines the temperature detected by each temperature sensor probe at the dew point moment based on this first moment.

[0071] The calculation module is also used to obtain the condensation position on the condensation surface based on the image output by the second imaging module, and obtain the distance between the positions of the at least two temperature detection points on the condensation surface and the condensation position, and determine the weights corresponding to the at least two temperature detection points based on the distance between the positions of the at least two temperature detection points and the condensation position. Optionally, the weight corresponding to the temperature detection point that is farther away from the condensation position is lower. The calculation module is used to calculate the dew point temperature at the condensation position based on the temperatures of the at least two temperature detection points and the weights corresponding to the at least two temperature detection points. In the case where the condensation surface area is large or the condensation surface is heated unevenly, the temperature of multiple points on the condensation surface is measured by multiple temperature sensors, and the temperature of the condensation position is calculated based on the temperature of the multiple points, which can improve the accuracy of the temperature measurement at the condensation position.

[0072] In some examples, the calculation module may be located within the upper cover structure or within the main structure, or the calculation module may include different components for performing different calculations, with the different components located in different locations. For example, the component of the calculation module for calculating water activity may be located within the upper cover structure, while the component for calculating water content may be located within the main structure, although this is not a limitation.

[0073] For example, in one example, as shown in FIG9 , FIG9 is a schematic diagram of the temperature detection points and condensation positions on the condensation surface in one embodiment of the present application. There are 9 temperature detection points (represented by 9 small dots in the figure) set on the condensation surface. The first temperature detection module detects that the temperatures of the 9 temperature detection points at the first moment are T1 to T9 respectively, and according to the condensation position L5 detected by the dew point detection module, the distances between the 9 temperature detection points and the condensation position are calculated to be d1 to d9. When calculating the distance between the temperature detection point and the condensation position, the distance between the temperature detection point and the centroid position of the dew point, or the distance to one of the edge positions of the dew point can be calculated. The distance can be the Euler distance, the straight-line distance, or other distances, which are not limited here. The first temperature detection module calculates the weights a1 to a9 of the 9 temperature detection points based on the distances d1 to d9. In one example, ai = 1 / di / (1 / d1 + 1 / d2 + 1 / d3 + 1 / d4 + 1 / d5 + 1 / d6 + 1 / d7 + 1 / d8 + 1 / d9), where i = 1, …, 9. The temperature at the condensation location is then calculated as T = a1*T1 + a2*T2 + a3*T3 + a4*T4 + a5*T5 + a6*T6 + a7*T7 + a8*T8 + a9*T9.

[0074] Optionally, the coffee particle detection device of the present application is used not only to detect the water activity of coffee particles, but also to detect other parameters of coffee particles, such as at least one of the following: moisture content, density, porosity, diameter, area, color, circularity, color uniformity, texture, and chromaticity. Optionally, the coffee particle detection device also includes an interface for displaying these parameters of the coffee particles. In one example, at least one of the diameter, area, color, circularity, color uniformity, texture, and chromaticity of the coffee particles can be obtained by identifying and acquiring the image output by the first imaging module. The color and chromaticity are calculated differently. For example, in one example, the calculation module acquires an image of the coffee particles and calculates the final color value based on the values ​​of different color channels of the image in a color space. The color space can be RGB, Lab, or HSV. In one example, the coffee particles are sequentially illuminated with light sources of different spectra to obtain images corresponding to different spectra. Different chromaticity diagrams corresponding to the different images are then obtained. The chromaticity value is then calculated based on a frame of the chromaticity diagram obtained by weighted processing of the different chromaticity diagrams.

[0075] Optionally, the calculation module can also classify the coffee particles into one of multiple preset grades based on the detected parameters. Optionally, the coffee particle device also includes a user interface for displaying the coffee particle grades to the user, allowing the user to have a more intuitive understanding of the detected coffee particles and quickly distinguish between lower-quality and higher-quality coffee beans. For example, as shown in Figure 4, the user interface 20 is located on the top surface of the upper cover structure 21. Optionally, the calculation module also pre-stores or provides real-time query guidance for at least one of the following: storage, roasting, grinding, and brewing of coffee beans of different grades. The user interface is further configured to display guidance corresponding to the coffee particle grade to the user. Optionally, the calculation module also pre-stores a prediction model and, based on the at least one parameter of the coffee beans and the prediction model, infers a pre-treatment method and / or pre-treatment time for the coffee beans. Optionally, the pre-treatment method includes at least one of the following: natural drying, washing, and honey treatment. The user interface is further configured to display the inferred results to the user. Optionally, the inference model can be obtained via a DNN neural network model. Alternatively, the inference model can be obtained through traditional machine learning methods, such as an SVM method. In one example, a preprocessing dataset is established, which includes at least one parameter selected from the group consisting of moisture content, density, porosity, diameter, area, color, circularity, color uniformity, texture, and chromaticity, and the corresponding preprocessing method and / or preprocessing date. This preprocessing dataset is then fed into a DNN neural network model for training to obtain an SVM model of these parameters and the preprocessing method and / or preprocessing date.

[0076] The following example illustrates how these parameters are detected for coffee particles.

[0077] As shown in Figure 10, Figure 10 is an exploded view of the chassis structure, electrode structure, and detachable inner liner of a coffee particle detection device according to one embodiment of the present application. Figure 11 is a schematic diagram of the assembly relationship of the chassis structure and electrode structure shown in Figure 10. The coffee particle detection device also includes a chassis structure 90 located within the main structure 22, an electrode contact 91 located on the chassis structure 90, a first electrode 92, and a second electrode 93. The first electrode 92 and the second electrode 93 are fixed to the chassis structure 93 and are respectively connected to different electrode contacts 91. When the detachable inner liner 23 is assembled into the main structure 22, the accommodating space 232 loaded with coffee particles is embedded between the first electrode 92 and the second electrode 93 to change the capacitance value between the first electrode 92 and the second electrode 93. The calculation module also includes a moisture content calculation module (not shown) located within the main structure 22, which is used to calculate the moisture content (MC) of the coffee particles based on the capacitance value between the first electrode 92 and the second electrode 93.

[0078] The structures of the first electrode 92 and the second electrode 93 can be various. In Figure 10, the first electrode 92 is a cylindrical electrode located on the chassis structure 93, and the second electrode 93 is annular and surrounds the first electrode 92, forming an annular hollow cavity between the first and second electrodes. As shown in Figure 12a, Figure 12a is a bottom side view of the removable inner liner shown in Figure 9. The removable inner liner 23 is at least partially made of a non-conductive material, and the bottom surface of the removable inner liner 23 is formed with a groove 233 extending into the accommodating space. The accommodating space is annular and surrounds the groove 233. When the removable inner liner 23 is fixed to the main structure, the accommodating space 232 in the removable inner liner 23 is embedded in the annular hollow cavity, and the first electrode is embedded in the groove 233 from the outside of the bottom surface of the removable inner liner 23. In other examples, the first and second electrodes can also be not cylindrical, but two rectangular blocks facing each other and side by side, without limitation.

[0079] The removable liner can be made entirely of plastic, or, in some examples, the removable liner includes a ring wall made of oxidized metal, and the bottom surface and the groove are made of a non-conductive material (e.g., plastic). Since a metal removable liner would shield the electric field and make it impossible to measure the moisture content of the coffee particles in the removable liner, the metal ring wall used in this example is stronger and more wear-resistant than plastic. In addition, the metal is non-conductive after oxidation, which can avoid affecting the distance between the first electrode and the second electrode and thus affecting the capacitance measurement.

[0080] In some examples, the bottom of the first electrode is set to be higher than the bottom of the second electrode so as to concentrate the electric field generated between the first electrode and the second electrode in the middle area of ​​the detachable inner liner, which can avoid the situation where the detachable inner liner cannot be completely placed in the annular hollow area between the first electrode and the second electrode when the depth is shallow, resulting in inaccurate moisture content measurement. As shown in Figure 12b, Figure 12b is a structural schematic diagram of the chassis structure and the first electrode of a coffee particle detection device of an embodiment of the present application. A base 95 is also provided on the chassis structure 90 at the bottom of the first electrode 92. The first electrode contact is provided on the base 95, and the first electrode 92 is fixed on the base 95 and connected to the first electrode contact, so that the bottom of the first electrode 92 is higher than the bottom of the second electrode.

[0081] Alternatively, in some examples, the electrode can be part of a removable liner. For example, as shown in Figures 13 and 14, Figure 13 is an exploded schematic diagram of the chassis structure and the removable liner of a coffee particle detection device according to an embodiment of the present application, and Figure 14 is a schematic diagram of the assembly relationship of the chassis structure and the removable liner shown in Figure 13. The coffee particle detection device includes a chassis structure 90 located within the main structure and an electrode contact 91 located on the chassis structure 90. A portion of the removable liner 23 is a first electrode 1411 and a portion is a second electrode 1412, and the first electrode 1411 and the second electrode 1412 are connected by a non-conductive material 1413. When the removable liner 23 is assembled into the main structure 22, the first electrode 1411 and the second electrode 1412 are in contact with different electrode contacts 90 respectively, and the accommodating space 232 is located between the first electrode 1411 and the second electrode 1412.

[0082] Optionally, the coffee particle detection device is equipped with removable liners of different sizes so that users can flexibly choose. For example, as shown in Figures 10 and 13, the coffee particle detection device is also equipped with removable liners 96 and 97 of small volume and small depth, respectively. In the example where the removable liners are made of non-conductive materials (such as plastic liners), compared to the removable liners containing electrodes, the plastic liners can be more convenient for users to operate the coffee particles to be tested, and the volume of the plastic liners is easier to customize and modify than the metal liners, which can better meet the user's customized needs. Compared with the example of the removable liners containing electrodes, the removable liners made of non-conductive materials will generate a fixed capacitance value C2 when placed between the electrodes in the main structure. Before the calculation module calculates the moisture content based on the capacitance value measured by the detection module and the relationship model, the capacitance value measured by the detection module is also subtracted from the fixed capacitance value C2.

[0083] The main structure of the coffee particle detection device also includes a detection circuit. This detection circuit includes a measured loop connected to the first electrode contact and the second electrode contact. When the removable inner container containing coffee particles is assembled to the main structure and measurement is performed, the measured loop is connected to detect the capacitance value C1 between the first electrode and the second electrode. The calculation module also includes a moisture content calculation module. This moisture content calculation module pre-stores a relationship model MC = f(C1) between the capacitance value C1 between the first electrode and the second electrode and the moisture content MC of the coffee particles. The corresponding moisture content can be calculated based on the capacitance value between the first electrode and the second electrode detected by the detection circuit and this relationship model. Optionally, the relationship model is a cubic fitting model for the capacitance value.

[0084] In some examples, the detection circuit is further provided with a temperature sensor for detecting temperature changes in the circuit. After measuring the capacitance value C1 between the first electrode and the second electrode, the calculation module is optionally further configured to correct the capacitance value C1 based on the temperature t measured by the temperature sensor. For example, the corrected capacitance C = C1 + k1 * t, where k1 is a fixed constant that can be determined experimentally.

[0085] In some examples, a reference loop is further provided in the detection circuit, and a reference capacitor with a known capacitance value C0 is provided on the reference loop. The moisture content calculation module pre-stores a relationship model MC=f(C_diff) between C_diff and the moisture content of the coffee particles, where C_diff is the difference between the capacitance value C1 between the first electrode and the second electrode detected by the detection circuit and the reference capacitance C0. The moisture content calculation module can calculate the corresponding moisture content based on the capacitance value C1 between the first electrode and the second electrode detected by the detection circuit, the capacitance value C0 of the reference capacitor, and the relationship model MC=f(C_diff). By setting the reference capacitor, the influence of errors can be eliminated during the calculation process. In one example, moisture content MC=b1*C_diff+b2*C_diff 2 +b3*C_diff 3 +b4, where b1, b2, b3, and b4 are model parameters obtained by fitting the experimental data.

[0086] In some examples, the detection circuit may measure the capacitance between the first electrode and the second electrode at a fixed electrode frequency. Alternatively, the electrode frequency may be varied. Since the capacitance between the first electrode and the second electrode changes with the electrode frequency, the detection circuit may also obtain at least two capacitance values ​​between the first electrode and the second electrode corresponding to at least two different electrode frequencies. The calculation module is further configured to calculate at least two moisture contents corresponding to the at least two capacitance values ​​based on the at least two capacitance values, and to perform a weighted calculation of the at least two moisture contents to obtain the moisture content of the coffee particles. For example, the detection circuit may detect a capacitance value C1 between the first electrode and the second electrode at electrode frequency f1, a capacitance value C2 between the first electrode and the second electrode at electrode frequency f2, and a capacitance value C3 between the first electrode and the second electrode at electrode frequency f3. The calculation module calculates the corresponding water activities MC1, MC2, and MC3 based on these three capacitance values, and then performs a weighted calculation to obtain the water activity of the coffee particles: MC = c1*MC1+c2*MC2+c3*MC3, where c1, c2, and c3 are the weighted values ​​of the three water activities, respectively. The weighted value can be pre-stored in the calculation module.

[0087] In some examples, the moisture content calculation module pre-stores relationship models for different coffee particle types. For example, the moisture content calculation module pre-stores at least one of the following: a first relationship model for green coffee beans, a second relationship model for roasted coffee beans, a third relationship model for dried coffee cherries, and a fourth relationship model for shelled coffee beans.

[0088] In the modern coffee industry, coffee beans have high requirements for drying and preservation. The amount of water in them directly affects the production quality and storage time. How to effectively check and control the moisture content of the substance is the key to keeping the substance dry. Moisture content has become one of the important indicators for evaluating the quality of coffee beans. For a long time, the measurement of moisture content has been mainly based on the loss on drying method, the principle of which is to heat the coffee particles so that the internal moisture of the coffee particles is evaporated, measure the weight of the sample before and after evaporation, and then calculate the weight of the lost water to obtain the moisture content. However, this method will waste coffee beans and is time-consuming. In the embodiment of the present application, a capacitive sensor is used to measure the capacitance change caused by the different moisture content of the object to establish a model between moisture content and capacitance value, which has the advantages of fast measurement speed and no loss.

[0089] In some examples, due to the wear and tear of the removable inner liner during long-term use, the wear and tear may cause deviations in the measurement of the moisture content of the coffee particles. Optionally, the calculation module is also used to obtain the pre-stored initial moisture content of the removable inner liner; obtain the current moisture content of the removable inner liner when it is empty; and correct the moisture content of the coffee particles according to the difference between the current moisture content and the initial moisture content. The initial moisture content may be the moisture content of the removable inner liner measured before leaving the factory and pre-stored by the coffee particle detection device. Optionally, before each user uses the coffee particle detection device to measure the moisture content, the user interface is also used to remind the user to insert an empty removable inner liner and measure the moisture content to obtain the current moisture content. Alternatively, instead of measuring the latest moisture content of the detachable inner liner every time the user uses the moisture content measurement function, the moisture content of the empty detachable inner liner can be measured at regular intervals, and the measured moisture content of the detachable inner liner can be used as the current moisture content of the detachable inner liner to correct the moisture content of the coffee particles over the next period of time.

[0090] When measuring the moisture content of coffee particles, gaps between them are inevitable due to their morphology. These gaps are typically filled with air, and the size of these gaps can affect the moisture content measurement. Theoretically, the denser the coffee particles, i.e., the smaller the gaps, the higher the moisture content. Alternatively, the gap ratio can be used to represent the size of the gaps between coffee particles. This ratio is the ratio of the interstitial area of ​​the coffee particles to the total area occupied by the coffee particles. Therefore, there is a certain relationship between the moisture content of coffee particles and the gap ratio. In some examples, the coffee particle detection device may pre-store a preset calibration model between the moisture content and the gap ratio. The calculation module also obtains the gap ratio of the coffee particles and calibrates the moisture content based on the gap ratio and the preset calibration model. In one example, the preset calibration model is MC = MC_0 + k2*R, where MC_0 is the initial moisture content, k2 is a fixed parameter obtained experimentally, R is the gap ratio, and MC is the moisture content after calibration. In some examples, the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles, and the calculation module is further used to correct the moisture content based on the temperature of the coffee particles detected by the second temperature detection module, the gap ratio and the preset correction model.

[0091] There are many ways to obtain the gap ratio of coffee particles. In one example, the coffee particle detection device also includes a third imaging module for imaging the coffee particles in the accommodating space. As shown in Figure 15, Figure 15 is a schematic diagram of an image of coffee particles 151 located in a removable inner liner 23 in an example. After obtaining the image, the calculation module calculates the total area occupied by the gaps between the coffee particles in the image through an image recognition method. Optionally, the calculation module can binarize the image of the coffee particles. For example, in the right image of Figure 15, black represents gaps and white represents coffee particles, and the gap area is obtained by calculating the area of ​​the black area. The calculation module also obtains the area of ​​the total area occupied by the coffee particles (that is, the opening area of ​​the removable inner liner) and uses this to calculate the gap ratio of the coffee particles. Optionally, the third imaging module and the above-mentioned first imaging module can be the same imaging module, and the imaging module can output different images respectively for calculating chromaticity, gap ratio, etc. Alternatively, the imaging module can be used to output an original image so that the calculation module can perform different processing and calculate different types of information based on the original image.

[0092] There are many ways to set the first imaging module or the third imaging module in the coffee particle detection device. In one example, as shown in Figure 16, Figure 16 is a bottom view of the upper cover structure of the coffee particle detection device in one embodiment of the present application. Taking the first imaging module as an example, the first imaging module is located in the upper cover structure 21, and the at least two light sources 161 with different spectra in the first imaging module are located at the second depth of the cavity, and the second depth is farther away from the accommodating space than the first depth. Specifically, in Figure 16, the at least two light sources 161 with different spectra are distributed in a ring shape on the second platform 162 located at the second depth of the cavity, and the direction of the emitted light is toward the main structure. Optionally, the photosensitive array is located at the third depth of the cavity. Optionally, as shown in Figure 16, the photosensitive array 163 is located on the central area of ​​the third platform 164 at the third depth of the cavity to image the coffee particles in the accommodating space.

[0093] Optionally, the coffee particle detection device further includes infrared anti-reflective glass located within the upper cover structure and between the first and third depths of the cavity to block the air passage between the photosensitive array and the accommodating space. Optionally, the infrared anti-reflective glass can be located between the first and second depths to further reduce the volume of the space connected to the accommodating space. By reducing the volume of the space connected to the accommodating space, equilibrium between the cavity temperature and the temperature of the coffee particles can be accelerated while maintaining the required distance between the photosensitive array and the coffee particles, thereby avoiding a situation where the distance between the photosensitive array and the coffee particles is too short and the temperature of all coffee particles cannot be imaged. Alternatively, in some examples, the distance between the photosensitive array and the coffee particles can be kept short to ensure that the volume of the space connected to the accommodating space is small, thereby ensuring that the cavity temperature and the temperature of the coffee particles reach equilibrium quickly. Furthermore, at least one reflector is disposed within the upper cover structure or the main body structure. The photosensitive array is configured to receive, via the at least one reflector, light reflected from the coffee particles by the at least two light beams of different spectra to image the coffee particles. In this way, the light path between the coffee particles and the photosensitive array can be extended by setting up a reflector. As shown in Figure 17, Figure 17 is a schematic diagram of the positional relationship between the photosensitive array, coffee particles and the reflector in one embodiment of the coffee particle detection device of the present application. The light beam reflected by the coffee particle 171 is reflected onto the photosensitive array 173 by the reflector 172. The mirror position 174 of the coffee particle and the original position 171 of the coffee particle are symmetrical about the reflector 172. By setting up the reflector, the distance between the coffee particles and the photosensitive array can be shortened while ensuring the optical path requirements between the coffee particles and the photosensitive array. There are many arrangements of the reflector and the photosensitive array. For example, both are located in the upper cover structure, wherein the photosensitive array can be located on the bottom or side of the upper cover structure. Alternatively, the reflector is located in the upper cover structure, and the photosensitive array is located in the main structure. In some examples, the number of reflectors can be one or at least two, which is not limited here.

[0094] In some examples, the first imaging module may be located not in the upper cover structure, but on the outside of the bottom of the removable inner liner. As shown in Figure 18a, Figure 18a is a schematic diagram of the positional relationship between the removable inner liner and the first imaging module in the coffee particle device in one embodiment of the present application. The bottom of the removable inner liner 23 is infrared anti-reflection glass. The light sources in the first imaging module 180 are located below the bottom of the removable inner liner 23, and are used to emit light beams to the bottom of the removable inner liner 23. The emitted light beams can pass through the bottom of the removable inner liner to illuminate the coffee particles 181 in the accommodating space, and are reflected by the coffee particles back to the photosensitive array located below the bottom of the removable inner liner. The field of view of the first imaging module 180 covers the entire bottom of the removable inner liner 23. Optionally, the light sources in the first imaging module are arranged around the photosensitive array. Of course, there are other arrangements of the light source and the photosensitive array, which are not limited here. In the example where the first imaging module is located within the upper cover structure, since the coffee particles within the accommodating space are imaged from the side of the opening of the accommodating space, it is necessary to ensure that the distance wave between the coffee particles and the first imaging module remains consistent during each chromaticity measurement to avoid inaccurate chromaticity measurements caused by varying distances between the coffee particles and the first imaging module. Generally, before measurement, it is necessary to ensure that the user fills the accommodating space with coffee particles to a fixed height and flattens the surface of the coffee particles to facilitate detection based on the image of the coffee particles. In the example where the first imaging module is located outside the bottom of the removable inner liner, since the distance between the bottom of the liner and the first imaging module remains fixed when the removable inner liner is secured within the device, the distance between the coffee particles within the removable inner liner and the first imaging module can remain fixed. This eliminates the need for the user to fill the accommodating space with coffee particles to a fixed height and then flatten the coffee particles, improving the user experience and avoiding chromaticity measurement errors caused by the user not filling the space with coffee particles to a fixed height or not flattening the space between each chromaticity measurement.

[0095] In some examples, coffee bean detection devices can also measure the density of coffee beans. Coffee beans are essentially like a honeycomb, consisting of a cellulose structure. This structure serves to store nutrients for the bean embryo. Denser coffee beans can store more sugars and lighter aromatic substances than less dense beans, resulting in a stronger flavor. Therefore, the density of green coffee beans is a key indicator for quality grading. Harder and denser green beans are generally more sought after and, accordingly, command a higher price. There are many methods for measuring coffee bean density. One existing method involves using a graduated cylinder. Coffee beans are poured to a line marked with a specific volume, weighed, and then divided by the specific volume. However, this method does not measure the true density of the coffee beans because there are spaces between the beans in the cylinder. Another existing method for measuring density is the displacement method. By adding a certain weight of green coffee to a certain volume of water and observing the change in water volume (i.e., the amount of water displaced), the actual volume of the coffee can be determined. The actual volume can be obtained by dividing the original weight of the coffee by its actual volume. However, this method is relatively cumbersome to operate.

[0096] In one embodiment of the present application, the coffee particle detection device can also compensate for the detected gap ratio to obtain a more accurate volume of the coffee particles. Specifically, as shown in Figure 11, the coffee particle detection device also includes a pressure sensor 94 located under the chassis structure 90 in the main structure, which is used to detect the weight of the coffee particles in the detachable inner liner. The calculation module is also used to calculate the volume of the coffee particles based on the gap ratio and the volume of the detachable inner liner, and to calculate the density of the coffee particles based on the weight of the coffee particles detected by the pressure sensor and the volume of the coffee particles. Optionally, in the example of calculating the density of coffee particles, the preset correction model can also be a relationship model between the gap ratio, the density and the moisture content; the calculation module is used to correct the moisture content based on the gap ratio, the density and the preset correction model. Optionally, the user interface in the coffee particle detection device is also used to display the density before correction and the density after correction for the gap ratio.

[0097] In some examples, the coffee particle detection device is pre-installed with a relationship model between coffee particle diameter, interstitial space ratio, density, and moisture content. The calculation module is further configured to calculate the diameter of the coffee particles based on the relationship model and the interstitial space ratio, density, and moisture content of the coffee particles. Optionally, the coffee particle detection device also includes a user interface for displaying the coffee particle diameter to a user. Optionally, the coffee particle detection device can also record the temperature and humidity of the environment in which the coffee particles are located using the temperature and humidity sensor, and record the measurement result as one of the coffee bean picking environment parameters. Optionally, the coffee particle detection device is also equipped with an air pressure sensor for measuring the air pressure of the environment in which the coffee beans are located. The calculation module is further configured to calculate altitude data based on the air pressure and record it as one of the coffee bean picking environment parameters. The user interface is further configured to display the temperature, humidity, air pressure, and altitude data as coffee bean picking environment data. By detecting, recording, and displaying the coffee bean picking environment, the coffee particle detection device allows users to more comprehensively detect and record relevant information about coffee particles. Optionally, the coffee particle detection device further includes a self-calibration kit for calibrating at least one measurement result of the coffee particle detection device. The self-calibration kit includes at least one of the following: a calibration liner, a calibration color card, a water activity standard solution, and a standard solution holding container. The calculation module is further configured to perform at least one of the following: compensating the moisture content measurement result of the coffee particles based on the moisture content measurement result of the calibration liner; compensating the colorimetric measurement result of the coffee particles based on the colorimetric measurement result of the calibration color card; and compensating the water activity measurement result of the coffee particles based on the water activity standard solution in the standard solution holding container.

[0098] As shown in Figure 18b, Figure 18b is a structural schematic diagram of a self-calibration kit in one embodiment of the present application. The self-calibration kit includes a calibration liner 182, a calibration color card 183, a water activity standard solution (not shown), and a standard solution holding container 184. The shape of the calibration liner 182 can be consistent with the shape of the detachable liner. The calculation module can compare the moisture content measurement result of the calibration liner with the moisture content of the pre-stored calibration liner, and compensate for the moisture content of the measured coffee particles based on the difference. The calibration color card 183 includes a flat portion 1831 with a color. When fixed to the calibration liner or the detachable liner, the flat portion 1831 is placed horizontally to measure the colorimetric value of the flat portion. The calculation module can compare the colorimetric value measurement result of the calibration color card with the colorimetric value of the pre-stored calibration color card, and compensate for the colorimetric value of the measured coffee particles based on the difference. The standard liquid holder 184 is fixed to the opening of the calibration inner container or the removable inner container and is used to hold the water activity standard liquid for measuring the water activity of the water activity standard liquid. The calculation module can compare the water activity measurement result of the standard liquid with the pre-stored water activity of the standard liquid and compensate the measured water activity of the coffee particles based on the difference.

[0099] The present application also provides a method for detecting coffee particles. As shown in FIG19 , FIG19 is a flow chart of an embodiment of the method for detecting coffee particles of the present application. The method includes: Step S1901, cooling a dew condensation surface having an air passage connected to a storage space, the storage space being used to store coffee particles, so that water vapor in the coffee particles condenses and forms dew on the dew condensation surface. Step S1902, detecting whether dew appears on the dew condensation surface. Step S1903, determining a first moment, the first moment being the moment when the dew point appears on the dew condensation surface. Step S1904, detecting the temperature of at least one location on the dew condensation surface, and determining the dew point temperature based on the temperature of the at least one location at the first moment. Step S1905, obtaining a first vapor pressure based on the dew point temperature. Step S1906, obtaining the temperature of the storage space and the coffee particles. Step S1907, obtaining a second vapor pressure based on the temperature of the storage space and the coffee particles. Step S1908: Calculate the water activity of the coffee particles based on the first vapor pressure and the second vapor pressure.

[0100] Optionally, the cooling of the condensation surface having an air passage connected to the accommodating space includes: in a first stage, controlling the refrigeration component at maximum power to cool the condensation surface to a first temperature; in a second stage, controlling the refrigeration component at dynamic power to cool the condensation surface, so that the condensation surface is cooled from the first temperature to the dew point temperature at a constant cooling rate; wherein, the cooling rate of the condensation surface in the second stage is lower than the cooling rate in the first stage.

[0101] Optionally, controlling the refrigeration component to cool the condensation surface to a first temperature at a first power level also includes obtaining the category of the coffee particles; and determining a value of the first temperature based on the category of the coffee particles. Optionally, the method further includes: obtaining a correspondence between the category of the coffee particles or different moisture contents and water activity ranges; obtaining the category of the coffee particles or different moisture contents; and determining a water activity range corresponding to the coffee particles based on the category of the coffee particles or different moisture contents and the correspondence; and controlling the refrigeration component to continue cooling when the water activity is not within the water activity range corresponding to the coffee particles.

[0102] Optionally, obtaining the category of the coffee particles includes: providing the user with options of different categories of coffee particles through an interactive interface; and determining the category of the coffee particles based on the option selected by the user. Optionally, the method further includes: emitting at least two light beams of different spectra toward the coffee particles in the accommodating space; receiving reflected light of the at least two light beams of different spectra from the coffee particles and imaging the coffee particles; and calculating the chromaticity value of the coffee particles based on the imaging of the coffee particles. Obtaining the category of the coffee particles includes: obtaining the category of the coffee particles based on the imaging of the coffee particles. Optionally, obtaining the category of the coffee particles includes: obtaining the moisture content of the coffee particles; and determining the category of the coffee particles based on the moisture content and a pre-stored correspondence between different moisture contents and categories of coffee particles.

[0103] Optionally, the detecting whether the dew appears on the condensation surface includes: detecting whether dew points appear on the condensation surface and / or the position of the dew on the condensation surface based on the grayscale values ​​of the imaging at different moments.

[0104] Optionally, detecting whether dew points appear on the dew condensation surface based on the grayscale values ​​of the images of the dew condensation surface at different times includes: obtaining the grayscale value mean of the images of the dew condensation surface at different times, and / or the grayscale value distribution of different sub-areas of the images of the dew condensation surface at different times; and determining whether dew points appear on the dew condensation surface based on the grayscale value mean and / or the grayscale value distribution. Optionally, the method further includes: obtaining an initial image of the dew condensation surface containing dew, and performing edge detection or texture feature detection on the dew in the initial image; when it is confirmed that the edge smoothness of the dew is greater than a preset threshold or the texture feature of the dew meets the requirements, confirming that the dew in the initial image is the dew.

[0105] Optionally, detecting whether dew has appeared on the dew condensation surface includes: emitting a laser beam from a laser emitter to cover the dew condensation surface; receiving the laser beam reflected by the dew condensation surface via a laser detector; generating an electrical signal based on the received laser beam; and confirming the presence of dew on the dew condensation surface based on changes in the electrical signal. Optionally, detecting the temperature of at least one location on the dew condensation surface and determining the dew point temperature based on the temperature of the at least one location at a first moment include: detecting the temperature using a platinum resistance sensor located on one side of the dew condensation surface; obtaining a hysteresis time of the platinum resistance sensor; and calculating the dew point temperature based on the temperature measured by the platinum resistance sensor at the hysteresis time after the first moment.

[0106] Optionally, the second vapor pressure is calculated based on an equilibrium temperature measured when the temperatures of the accommodating space and the coffee particles reach equilibrium; the method further includes: obtaining a pre-stored first relationship model between water activity measured at an equilibrium temperature of 25 degrees Celsius and water activity measured at other equilibrium temperatures; and calculating the water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius based on the equilibrium temperature, the water activity, and the first relationship model. Optionally, the second vapor pressure is calculated based on a temperature when the temperatures of the accommodating space and the coffee particles do not reach equilibrium; the method further includes: obtaining a pre-stored second relationship model between water activity measured at an equilibrium temperature of 25 degrees Celsius and water activity measured at other non-equilibrium temperatures; and calculating the water activity of the coffee particles corresponding to the equilibrium temperature of 25 degrees Celsius based on the temperatures of the accommodating space and the coffee particles, the water activity, and the second relationship model.

[0107] Optionally, the method further comprises: obtaining at least one of the following parameters of the coffee particles: moisture content, density, porosity, diameter, area, color, circularity, color uniformity, texture, and chroma.

[0108] Optionally, the method further includes: placing the accommodating space between a first electrode and a second electrode to change the capacitance value between the first electrode and the second electrode; detecting the capacitance value between the first electrode and the second electrode by a detection circuit; and calculating the moisture content of the coffee particles based on the capacitance value between the first electrode and the second electrode. Optionally, the detection circuit includes a measured loop and a reference loop, and a reference capacitor with a known capacitance value is provided on the reference loop; the method further includes obtaining a capacitance difference between the capacitance value between the first electrode and the second electrode detected by the detection circuit and the capacitance value of the reference capacitor; calculating the moisture content of the coffee particles based on the capacitance value between the first electrode and the second electrode includes: calculating the moisture content of the coffee particles based on a pre-stored relationship model between the capacitance difference and the moisture content and the obtained capacitance difference. Optionally, detecting the capacitance value between the first electrode and the second electrode by a detection circuit includes: obtaining at least two capacitance values ​​between the first electrode and the second electrode corresponding to at least two different electrode frequencies; calculating the moisture content of the coffee particles based on the capacitance value between the first electrode and the second electrode includes: calculating at least two moisture contents corresponding to the at least two capacitance values, and performing weighted calculation of the at least two moisture contents to obtain the moisture content of the coffee particles.

[0109] Optionally, the method further includes: obtaining a pre-stored preset correction model, wherein the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; imaging the coffee particles within the accommodation space; obtaining the gap ratio of the coffee particles based on the imaging; and correcting the moisture content based on the gap ratio and the preset correction model. Optionally, the preset correction model is a relationship model between the moisture content and at least the gap ratio and the temperature of the coffee particles; the method further includes: detecting the temperature of the coffee particles; and correcting the moisture content based on the detected temperature of the coffee particles, the gap ratio, and the preset correction model. Optionally, the method further includes: detecting the weight of the coffee particles using a pressure sensor; calculating the volume of the coffee particles based on the gap ratio and the volume of the accommodation space; and calculating the density of the coffee particles based on the weight of the coffee particles detected by the pressure sensor and the volume of the coffee particles. Optionally, the preset correction model is a relationship model among the void ratio, the density and the moisture content; and the correcting the moisture content according to the void ratio and the preset correction model includes: correcting the moisture content according to the void ratio, the density and the preset correction model.

[0110] Optionally, the method further includes: obtaining a pre-stored relationship model between the diameter and gap ratio, density and moisture content of coffee particles; calculating the diameter of the coffee particles based on the relationship model, the gap ratio, the density and the moisture content; and displaying the diameter of the coffee particles to the user through a user interface.

[0111] Optionally, the method further includes classifying the coffee particles into one of a plurality of preset grades based on at least one of the following parameters: color, texture, diameter, area, roundness, color uniformity, and chroma; and displaying the grade of the coffee particles to a user via a user interface. Optionally, the method further includes obtaining pre-stored or real-time guidance for at least one of the following: storage, roasting, grinding, and brewing of coffee beans of different grades; and displaying the guidance corresponding to the grade of the coffee particles via the user interface. Optionally, the method further includes obtaining a pre-stored inference model; inferring a pre-treatment method and / or pre-treatment time for the coffee particles based on the at least one parameter of the coffee beans and the inference model; and displaying the pre-treatment method and / or pre-treatment time to the user via the user interface. Optionally, the method further includes obtaining a pre-stored initial moisture content of the removable inner container; obtaining a current moisture content of the removable inner container when empty; and correcting the moisture content of the coffee particles based on the difference between the current moisture content and the initial moisture content.

[0112] Optionally, the method further includes: detecting the temperature and humidity of the environment in which the coffee beans are located using a humidity sensor; detecting the air pressure of the environment in which the coffee beans are located using a pressure sensor; calculating altitude data based on the air pressure; and displaying the temperature, humidity, air pressure, and altitude data as coffee bean picking environment data via a user interface. Optionally, the method further includes at least one of the following steps: compensating the moisture content measurement result of the coffee particles based on the moisture content measurement result of a calibration liner; compensating the colorimetric measurement result of the coffee particles based on the colorimetric measurement result of a calibration color chart; and compensating the water activity measurement result of the coffee particles based on the water activity standard solution measurement result in a standard solution holding container.

[0113] For an explanation of the coffee particle detection method, please refer to the above explanation of the coffee particle device, which will not be repeated here.

[0114] The embodiments of the present application have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A coffee granule detection device, characterized in that, It includes a containing space, a condensation surface, a cooling module, a first temperature detection module, a dew point detection module, and a calculation module; The containing space is used to contain coffee particles; There is a connected air passage between the condensation surface and the containing space; The cooling module is used to cool down the condensation surface so that water vapor in the coffee particles condenses into dew on the condensation surface; The dew point detection module is used to detect whether dew appears on the condensation surface; The first temperature detection module is used to detect the temperature at at least one place on the condensation surface; The calculation module is used to: Determine the first moment, which is the moment when dew is detected on the condensation surface; Determine the dew point temperature according to the first moment and the temperature at at least one place; Obtain the first vapor pressure according to the dew point temperature; Obtain the temperatures of the containing space and the coffee particles; Obtain the second vapor pressure according to the temperatures of the containing space and the coffee particles; And Calculate the water activity of the coffee particles according to the first vapor pressure and the second vapor pressure.

2. The device according to claim 1, characterized in that, The cooling module includes a refrigeration component and a control component. The control component is used to control the refrigeration component to cool down the condensation surface to the first temperature at the maximum power in the first stage, and control the refrigeration component to cool down the condensation surface at a dynamic power in the second stage, so that the condensation surface cools down from the first temperature to the dew point temperature at a constant cooling rate; wherein, the cooling rate of the condensation surface in the second stage is lower than that in the first stage.

3. The device according to claim 2, characterized in that The device pre-stores the first temperatures corresponding to different categories of coffee particles respectively; The control component is also used to obtain the category of the coffee particles and determine the value of the first temperature according to the category of the coffee particles.

4. The device according to claim 2, wherein The device also pre-stores the corresponding relationships between different categories of coffee particles or different moisture contents and water activity ranges; The control component is also used to obtain the category of the coffee particles or the moisture content of the coffee particles, confirm the water activity range corresponding to the coffee particles according to the category of the coffee particles or the moisture content of the coffee particles, and when the water activity is not within the water activity range corresponding to the coffee particles, control the refrigeration component to continue cooling.

5. The device according to claim 3 or 4, characterized in that, The device further includes a first imaging module. The first imaging module includes light sources of at least two different spectra, which are used to sequentially emit light beams of different spectra into the containing space of the coffee particles; the first imaging module further includes a photosensitive array used to sequentially receive the reflected light of the coffee particles on the at least two different spectra of light beams and image the coffee particles in sequence, wherein the photosensitive array is used to generate at least two frames of images corresponding to the at least two light sources respectively; The calculation module is also used to calculate the chromaticity value of the coffee particles according to the at least two frames of images; The control component is also used to obtain the category of the coffee particles according to the imaging of the coffee particles.

6. The device according to claim 3 or 4, characterized in that, The device also pre-stores the corresponding relationships between different moisture contents and the categories of coffee particles; The control component is further configured to obtain the moisture content of the coffee particles and determine the category of the coffee particles according to the moisture content.

7. The device according to claim 2, characterized in that, The cooling component is located on one side of the condensation surface. The device further includes a heat sink disposed adjacent to the cooling component on the side opposite to the condensation surface and a heat sink fan disposed adjacent to the heat sink.

8. The device according to claim 1, characterized in that The device further includes a circulation fan located on one side of the condensation surface and a motor for driving the circulation fan. The circulation fan is configured to increase the air circulation speed between the accommodation space and the condensation surface.

9. The device according to claim 1, characterized in that, The dew point detection module is further configured to detect the dew condensation position on the condensation surface; The first temperature detection module is configured to obtain the temperatures at at least two positions on the condensation surface; The calculation module is configured to obtain the distances between the at least two positions and the dew condensation position respectively, determine the weights corresponding to the at least two positions respectively according to the distances between the at least two positions and the dew condensation position respectively, and calculate the dew point temperature according to the temperatures at the at least two positions and the weights corresponding to the at least two positions respectively.

10. The device according to claim 1, characterized in that, The dew point detection module includes a second imaging module configured to obtain images of the condensation surface at different times; The calculation module is further configured to detect whether dew appears on the condensation surface and / or the position of the dew on the condensation surface according to the gray scale values of the images at different times.

11. The device according to claim 10, characterized in that, The calculation module is configured to obtain the average gray scale value of the images of the condensation surface at different times and the gray scale value distribution of different regions on the images of the condensation surface at different times to determine whether dew appears on the condensation surface.

12. The device according to claim 1, characterized in that, The dew point detection module includes a second imaging module configured to obtain images of the condensation surface at different times; The calculation module is further configured to obtain an initial image of the condensation surface containing dew and perform edge detection or texture feature detection on the dew in the initial image; When it is confirmed that the edge smoothness of the dew is greater than a preset threshold or the texture feature of the dew meets the requirements, the dew in the initial image is confirmed as the dew.

13. The device according to claim 1, characterized in that, The dew point detection module includes a laser emitter and a laser detector; The laser beam emitted by the laser emitter covers the condensation surface. The laser detector is configured to receive the laser beam reflected by the condensation surface and generate an electrical signal according to the received laser beam; The calculation module is further configured to confirm that dew appears on the condensation surface according to the change of the electrical signal.

14. The device according to claim 1, characterized in that, The first temperature detection module includes a platinum resistance sensor located on one side of the condensation surface, The calculation module is configured to obtain the lag time of the platinum resistance sensor and calculate the dew point temperature according to the temperature measured by the platinum resistance sensor at the lag time after the first moment.

15. The device according to claim 1, characterized in that, The second vapor pressure is calculated according to the equilibrium temperature measured when the temperature of the accommodation space and the coffee particles reaches equilibrium; The calculation module prestores a first relationship model between the water activity measured at the equilibrium temperature of 25 degrees Celsius and the water activity measured at other equilibrium temperatures; The calculation module is further configured to calculate the water activity corresponding to the equilibrium temperature of 25 °C of the coffee particles according to the equilibrium temperature, the water activity, and the first relationship model.

16. The device according to claim 1, characterized in that The second vapor pressure is calculated according to the accommodation space and the temperature when the temperature of the coffee particles has not reached equilibrium. The calculation module prestores a second relationship model between the water activity measured at the equilibrium temperature of 25 °C and the water activity measured at other non-equilibrium temperatures. The calculation module is further configured to calculate the water activity corresponding to the equilibrium temperature of 25 °C of the coffee particles according to the accommodation space, the temperature of the coffee particles, the water activity, and the second relationship model.

17. The device according to claim 1, characterized in that, The device is further configured to obtain at least one of the following parameters of the coffee particles: Moisture content, density, void fraction, diameter, area, color, roundness, color uniformity, texture, chromaticity.

18. The device according to claim 1, characterized in that, The device includes an upper cover structure and a main body structure that are movably connected. The device further includes a detachable inner container located within the main body structure. The accommodation space is located within the detachable inner container. The device further includes a chassis structure, a first electrode, and a second electrode that are fixed within the main body structure and have first electrode contacts and second electrode contacts provided on their surfaces. The first electrode and the second electrode are fixed to the chassis structure and are respectively connected to the first electrode contact and the second electrode contact. When the detachable inner container is combined into the main body structure, the accommodation space is embedded between the first electrode and the second electrode to change the capacitance value between the first electrode and the second electrode. The calculation module is further configured to calculate the moisture content of the coffee particles according to the capacitance value between the first electrode and the second electrode.

19. The device according to claim 18, characterized in that, The first electrode is located on the chassis structure, and the second electrode is in a ring shape surrounding the first electrode, such that a ring-shaped hollow cavity is formed between the first electrode and the second electrode. At least a portion of the detachable inner container is made of a non-conductive material, and a groove extending towards the accommodation space is formed on the bottom surface of the detachable inner container. The accommodation space is in a ring shape surrounding the groove. When the detachable inner container is fixed to the main body structure, the accommodation space in the detachable inner container is embedded into the ring-shaped hollow cavity, and the first electrode is embedded into the groove from the outside of the bottom surface of the detachable inner container.

20. The device according to claim 19, characterized in that, The detachable inner container includes a ring wall made of metal after oxidation treatment, and a bottom surface and a groove made of a non-conductive material.

21. The device according to claim 18, characterized in that, A base is provided on the chassis structure at the bottom of the first electrode. The first electrode contact is provided on the base, and the first electrode is fixed on the base and connected to the first electrode contact, such that the bottom of the first electrode is higher than the bottom of the second electrode.

22. The device according to claim 1, characterized in that The device includes an upper cover structure and a main body structure that are movably connected. The device includes a chassis structure located within the main body structure and having first electrode contacts and second electrode contacts provided on its surface. A part of the detachable inner container serves as a first electrode and another part serves as a second electrode. When the detachable inner container is combined with the main body structure, the first electrode contacts the first electrode contact, the second electrode contacts the second electrode contact, and the accommodation space is located between the first electrode and the second electrode. The calculation module is further configured to calculate the moisture content of the coffee particles based on the capacitance value between the first electrode and the second electrode.

23. The device according to any one of claims 18 to 22, characterized in that The device further includes a detection circuit located within the main body structure. The detection circuit includes a measured loop and a reference loop. The first electrode contact and the second electrode contact are located on the measured loop, and a reference capacitor with a known capacitance value is provided on the reference loop. The calculation module is configured to obtain the capacitance difference between the capacitance value between the first electrode and the second electrode detected by the detection circuit and the capacitance value of the reference capacitor. The calculation module is further configured to calculate the moisture content of the coffee particles based on the pre-stored relationship model between the capacitance difference and the moisture content and the obtained capacitance difference.

24. The device according to claim 23, wherein The detection circuit is further configured to obtain at least two capacitance values corresponding to at least two different electrode frequencies between the first electrode and the second electrode. The calculation module is further configured to calculate at least two corresponding moisture contents based on the at least two capacitance values, and calculate the moisture content of the coffee particles by weighted calculation of the at least two moisture contents.

25. The device according to any one of claims 18 to 22, characterized in that, The joint surface, the cooling module, the first temperature detection module, and the dew point detection module are located within the upper cover structure; a third imaging module is further provided within the upper cover structure for imaging the coffee particles within the accommodation space. A preset correction model is pre-stored within the device for indicating the relationship between the moisture content and at least the void ratio. The calculation module is further configured to obtain the void ratio of the coffee particles based on the imaging, and correct the moisture content based on the void ratio and the preset correction model.

26. The device according to claim 25, characterized in that, The preset correction model is a relationship model between the moisture content and at least the void ratio and the temperature of the coffee particles. The device further includes a second temperature detection module for detecting the temperature of the coffee particles. The calculation module is configured to correct the moisture content based on the temperature of the coffee particles detected by the second temperature detection module, the void ratio, and the preset correction model.

27. The device according to claim 25, characterized in that, The device further includes a pressure sensor located under the chassis structure within the main body structure for detecting the weight of the coffee particles within the detachable inner container. The calculation module is further configured to calculate the volume of the coffee particles based on the void ratio and the volume of the detachable inner container, and calculate the density of the coffee particles based on the weight of the coffee particles detected by the pressure sensor and the volume of the coffee particles.

28. The device according to claim 27, characterized in that, The preset correction model is a relationship model between the moisture content and at least the void ratio and the density. The calculation module is configured to correct the moisture content based on the void ratio, the density, and the preset correction model.

29. The device according to claim 17, wherein A relationship model between the diameter, void fraction, density, and moisture content of coffee particles is also preset in the device. The calculation module is further configured to calculate the diameter of the coffee particles according to the relationship model, the void fraction, the density, and the moisture content. The device further includes a user interface for presenting the diameter of the coffee particles to the user.

30. The device according to claim 17, characterized in that The calculation module is further configured to classify the coffee particles into one of multiple preset grades according to at least one of the following parameters: color, texture, diameter, area, circularity, color uniformity. The user interface is further configured to present the grade of the coffee particles to the user.

31. The device according to claim 30, wherein The calculation module is further configured to pre-store or query in real time guidance suggestions for at least one of storage, roasting, grinding, and brewing of coffee beans of different grades. The user interface is further configured to present the guidance suggestions corresponding to the grade of the coffee particles.

32. The device according to claim 30, wherein The calculation module further pre-stores a speculation model, and speculates the pretreatment method and / or pretreatment time of the coffee particles according to the at least one parameter of the coffee beans and the speculation model. The user interface is further configured to present the pretreatment method and / or pretreatment time to the user.

33. The device according to claim 18, characterized in that, The calculation module is further configured to: Obtain the initial moisture content of the detachable inner container pre-stored. Obtain the current moisture content of the detachable inner container when it is empty. Correct the moisture content of the coffee particles according to the difference between the current moisture content and the initial moisture content.

34. The device according to claim 5, characterized in that, The device includes an upper cover structure and a main body structure that are movably connected, and the accommodation space is located within the main body structure. The upper cover structure includes a concave cavity, and when the upper cover structure covers the main body structure, the concave cavity communicates with the accommodation space. A first platform is provided at a first depth of the concave cavity, and the exposure surface is located on the first platform. The first imaging module is located within the upper cover structure, and at least two light sources of different spectra are located at a second depth of the concave cavity, and the second depth is farther from the accommodation space than the first depth.

35. The device according to claim 34, characterized in that, The photosensitive array is located at a third depth of the concave cavity; an infrared antireflection glass is also provided within the upper cover structure between the first depth and the third depth of the concave cavity to block the air passage between the first imaging module and the accommodation space; or, At least one reflector is further provided within the upper cover structure or within the main body structure, and the second imaging module is configured to receive the reflected light of the coffee particles on the at least two light beams of different spectra through the at least one reflector to image the coffee particles.

36. The device according to claim 5, characterized in that The device includes an upper cover structure and a main body structure that are movably connected. The device further includes a detachable inner container located within the main body structure. The accommodation space is located within the detachable inner container, and the bottom of the detachable inner container is an infrared antireflection glass. The first imaging module is located below the bottom of the detachable inner container.

37. The device according to claim 1, characterized in that, The device further includes a temperature and humidity sensor for detecting the temperature and humidity of the environment where the coffee beans are located. The device further includes a barometric pressure sensor for detecting the barometric pressure of the environment where the coffee beans are located. The calculation module is further configured to calculate altitude data according to the barometric pressure. The user interface is also used to display the temperature and humidity, the air pressure, and the altitude data as the picking environment data of the coffee beans.

38. The device according to claim 1, characterized in that, The device further includes a calibration kit, and the self-calibration kit includes at least one of the following: a calibration inner container, a calibration color card, a water activity standard solution, and a standard solution carrier container; The calculation module is further configured to perform at least one of the following: Compensate the moisture content measurement result of the coffee particles according to the measurement result of the moisture content of the calibration inner container; Compensate the chromaticity measurement result of the coffee particles according to the measurement result of the chromaticity of the calibration color card; Compensate the water activity measurement result of the coffee particles according to the measurement result of the water activity standard solution in the standard solution carrier container.

39. A method for detecting coffee granules, characterized in that, Including: Cooling the condensation surface of the air passage communicating with the accommodation space, where the accommodation space is used to accommodate coffee particles, so that the water vapor in the coffee particles condenses into water and dew is precipitated on the condensation surface; Detecting whether dew appears on the condensation surface; Determining a first moment, where the first moment is the moment when dew is detected on the condensation surface; Detecting the temperature of at least one location on the condensation surface, and determining the dew point temperature according to the temperature of the at least one location at the first moment; Obtaining a first vapor pressure according to the dew point temperature; Obtaining the temperature of the accommodation space and the coffee particles; Obtaining a second vapor pressure according to the temperature of the accommodation space and the coffee particles; Calculating the water activity of the coffee particles according to the first vapor pressure and the second vapor pressure.

40. The method according to claim 39, wherein The cooling of the condensation surface of the air passage communicating with the accommodation space includes: Controlling the refrigeration component at the maximum power in the first stage to cool the condensation surface to a first temperature; In the second stage, controlling the refrigeration component to cool the condensation surface with a dynamic power, so that the condensation surface is cooled from the first temperature to the dew point temperature at a constant cooling rate; Wherein, the cooling rate of the condensation surface in the second stage is lower than that in the first stage.

41. The method according to claim 40, wherein Before controlling the refrigeration component to cool the condensation surface to the first temperature with the first power, it further includes: Obtaining the category of the coffee particles; Determining the value of the first temperature according to the category of the coffee particles.

42. The method according to claim 40, wherein The method further includes: Obtaining the category of the coffee particles or the corresponding relationship between different moisture contents and water activity intervals; Obtaining the category of the coffee particles or different moisture contents; Confirming the water activity interval corresponding to the coffee particles according to the category of the coffee particles or different moisture contents and the corresponding relationship; When the water activity is not within the water activity interval corresponding to the coffee particles, controlling the refrigeration component to continue cooling.

43. The method according to claim 40 or 41, characterized in that, The obtaining of the category of the coffee particles includes: Providing options of different categories of coffee particles to the user through an interaction interface; Determining the category of the coffee particles according to the option selected by the user.

44. The method according to claim 40 or 41, characterized in that, The method further includes: Emitting at least two different spectral beams to the coffee particles in the accommodation space; Receiving the reflected light of the at least two different spectral beams by the coffee particles and imaging the coffee particles; Calculating the chromaticity value of the coffee particles based on the imaging of the coffee particles; Obtaining the category of the coffee particles includes: Obtaining the category of the coffee particles based on the imaging of the coffee particles.

45. The method according to claim 40 or 41, characterized in that, Obtaining the category of the coffee particles includes: Obtaining the moisture content of the coffee particles; Determining the category of the coffee particles according to the moisture content and the pre-stored correspondence between different moisture contents and the categories of coffee particles.

46. The method according to claim 39, characterized in that, Detecting whether dew appears on the dew condensation surface includes: Detecting whether a dew point and / or the position of the dew on the dew condensation surface appears according to the gray values of the imaging at different times.

47. The method according to claim 46, wherein Detecting whether a dew point appears on the dew condensation surface according to the gray values of the imaging of the dew condensation surface at different times includes: Obtaining the average gray value of the imaging of the dew condensation surface at different times, and / or the gray value distribution of different regions on the imaging of the dew condensation surface at different times; Determining whether a dew point appears on the dew condensation surface according to the average gray value and / or the gray value distribution.

48. The method according to claim 39, wherein The method further includes: Obtaining the initial imaging of the dew condensation surface containing dew, and performing edge detection or texture feature detection on the dew in the initial imaging; When it is confirmed that the edge smoothness of the dew is greater than a preset threshold or the texture feature of the dew meets the requirements, confirming that the dew in the initial imaging is the dew.

49. The method according to claim 39, wherein Detecting whether dew appears on the dew condensation surface includes: Emitting a laser beam from a laser emitter to cover the dew condensation surface; Receiving the laser beam reflected by the dew condensation surface through a laser detector; Generating an electrical signal according to the received laser beam; Confirming that dew appears on the dew condensation surface according to the change of the electrical signal.

50. The method according to claim 39, wherein Detecting the temperature of at least one place on the dew condensation surface, and determining the dew point temperature according to the temperature of the at least one place at the first moment includes: Detecting the temperature through a platinum resistance sensor located on one side of the dew condensation surface; Obtaining the hysteresis duration of the platinum resistance sensor; Calculating the dew point temperature according to the temperature measured by the platinum resistance sensor at the hysteresis duration after the first moment.

51. The method according to claim 39, wherein The second vapor pressure is calculated according to the equilibrium temperature measured when the temperature of the accommodation space and the coffee particles reaches equilibrium; the method further includes: Obtaining the first relationship model between the water activity measured at the equilibrium temperature of 25 °C and the water activity measured at other equilibrium temperatures stored in advance; Calculating the water activity corresponding to the equilibrium temperature of 25 °C of the coffee particles according to the equilibrium temperature, the water activity and the first relationship model.

52. The method according to claim 39, wherein The second vapor pressure is calculated according to the temperature when the temperature of the accommodation space and the coffee particles does not reach equilibrium; the method further includes: Obtaining the second relationship model between the water activity measured at the equilibrium temperature of 25 °C and the water activity measured at other non-equilibrium temperatures stored in advance; Calculating the water activity corresponding to the equilibrium temperature of 25 °C of the coffee particles according to the temperature of the accommodation space and the coffee particles, the water activity and the second relationship model.

53. The method according to claim 39, characterized in that, The method further includes: Obtaining at least one of the following parameters of the coffee particles: Water content, density, void ratio, diameter, area, color, roundness, color uniformity, texture, chromaticity.

54. The method according to claim 39, characterized in that, The method further includes: Placing the accommodation space between a first electrode and a second electrode to change the capacitance value between the first electrode and the second electrode; Detecting the capacitance value between the first electrode and the second electrode through a detection circuit; Calculating the water content of the coffee particles according to the capacitance value between the first electrode and the second electrode.

55. The method according to claim 54, characterized in that, The detection circuit includes a measured loop and a reference loop, and a reference capacitor with a known capacitance value is provided on the reference loop; The method further includes obtaining a capacitance difference between the capacitance value between the first electrode and the second electrode detected by the detection circuit and the capacitance value of the reference capacitor; The calculating the water content of the coffee particles according to the capacitance value between the first electrode and the second electrode includes: Calculating the water content of the coffee particles according to a pre-stored relationship model between the capacitance difference and the water content and the obtained capacitance difference.

56. The method according to claim 54, characterized in that, The detecting the capacitance value between the first electrode and the second electrode through a detection circuit includes: obtaining at least two capacitance values corresponding to at least two different electrode frequencies between the first electrode and the second electrode respectively; The calculating the water content of the coffee particles according to the capacitance value between the first electrode and the second electrode includes: Calculating at least two corresponding water contents according to the at least two capacitance values, and calculating the water content of the coffee particles by weighting the at least two water contents.

57. The method according to claim 54, characterized in that, The method further includes: Obtaining a pre-stored preset correction model, where the preset correction model is a relationship model between the water content and at least the void ratio and the temperature of the coffee particles; Imaging the coffee particles in the accommodation space; Obtaining the void ratio of the coffee particles according to the imaging; Correcting the water content according to the void ratio and the preset correction model.

58. The method according to claim 57, wherein The preset correction model is a relationship model between the water content and at least the void ratio and the temperature of the coffee particles; The method further includes: Detecting the temperature of the coffee particles; Correcting the water content according to the detected temperature of the coffee particles, the void ratio and the preset correction model.

59. The method according to claim 57, wherein The method further includes: Detecting the weight of the coffee particles through a pressure sensor; Calculating the volume of the coffee particles according to the void ratio and the volume of the accommodation space; Calculating the density of the coffee particles according to the weight of the coffee particles detected by the pressure sensor and the volume of the coffee particles.

60. The method according to claim 59, wherein The preset correction model is a relationship model between the void ratio, the density and the water content; The correcting the water content according to the void ratio and the preset correction model includes: Correcting the water content according to the void ratio, the density and the preset correction model.

61. The method according to claim 49, characterized in that, The method further includes: Obtaining a pre-stored relationship model between the diameter of the coffee particles and the void ratio, density and water content; Calculating the diameter of the coffee particles according to the relationship model, the void ratio, the density and the water content. Display the diameter of the coffee particles to the user through the user interface.

62. The method according to claim 49, characterized in that The method further includes: Classify the coffee particles into one of multiple preset grades according to at least one of the following parameters: color, texture, diameter, area, roundness, color uniformity, chromaticity; The user interface is further used to display the grade of the coffee particles to the user.

63. The method according to claim 62, wherein The method further includes: Obtain stored or real-time query guidance suggestions for at least one of storage, roasting, grinding, and brewing of coffee beans of different grades; Display the guidance suggestions corresponding to the grade of the coffee particles through the user interface.

64. The method according to claim 62, wherein The method further includes: Obtain a pre-stored speculation model; Speculate on the pretreatment method and / or pretreatment time of the coffee particles based on the at least one parameter of the coffee beans and the speculation model; Display the pretreatment method and / or pretreatment time to the user through the user interface.

65. The method according to claim 49, wherein The method further includes: Obtain the initial moisture content of the detachable inner container stored in advance; Obtain the current moisture content of the detachable inner container when it is empty; Correct the moisture content of the coffee particles according to the difference between the current moisture content and the initial moisture content.

66. The method according to claim 39, wherein The method further includes: Detect the temperature and humidity of the environment where the coffee beans are located through a humidity sensor; Detect the air pressure of the environment where the coffee beans are located through a barometric pressure sensor; Calculate altitude data based on the air pressure; Display the temperature and humidity, the air pressure, and the altitude data as the picking environment data of the coffee beans through the user interface.

67. The method according to claim 39, characterized in that, The device further includes a calibration kit, and the method further includes at least one of the following steps: Compensate the moisture content measurement result of the coffee particles according to the measurement result of the moisture content of the calibration inner container; Compensate the chromaticity measurement result of the coffee particles according to the measurement result of the chromaticity of the calibration color card; Compensate the water activity measurement result of the coffee particles according to the measurement result of the water activity standard solution in the standard solution carrier container.

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