A measuring system and method for the gap of a grinder burr disc

Abstract

The present application relates to a kind of measuring systems for the gap of grinder blade, system includes displacement acquisition module, signal amplification module, signal conversion module and main control unit, the output of displacement acquisition module is electrically connected with the input of signal amplification module, the output of signal amplification module is electrically connected with the input of signal conversion module, the output of signal conversion module is electrically connected with the input of main control unit;Displacement acquisition module includes VCP1612 type linear position sensor, for when the gap distance of grinder blade is collected during the relative displacement of grinder upper and lower blade, generate first electrical signal;Signal amplification module, for receiving first electrical signal and amplifying it, generate second electrical signal;Signal conversion module, for receiving second electrical signal and converting it into digital signal;Main control unit, for receiving digital signal and analyzing and calculating the displacement information of grinder blade gap adjustment rod, so that the gap value of grinder blade is obtained.

Description

Technical Field

[0001] This invention relates to the field of coffee grinder technology, and more specifically to a measurement system and method for the gap between the burr blades of a coffee grinder. Background Technology

[0002] With rapid economic development and continuous technological advancements, national consumption levels have gradually increased, leading to a booming coffee industry. In the coffee preparation process, precise control of the grinder blade gap is a crucial factor affecting coffee extraction results, making its measurement technology vital in the coffee grinder industry. However, during long-term heavy use, the grinder blade gap is prone to changes due to wear and other factors, necessitating an efficient and reliable grinder gap measurement system for intuitive detection and real-time monitoring.

[0003] The "grind setting" on traditional coffee grinders is essentially a relative value, only reflecting the change in coarseness compared to the previous grind, and cannot intuitively show the specific value of the blade gap (such as how many micrometers). More importantly, the "0 mark" set by the factory for traditional coffee grinders lacks a unified standard, which may lead to problems such as "the blade is stuck at the 0 mark" or "the gap is still too large at the 0 mark". This results in a lack of accurate benchmark for grinding precision control, making it difficult to meet the needs of high-precision coffee preparation.

[0004] Therefore, how to accurately measure the specific value of the gap between the burrs of a coffee grinder in order to achieve higher precision coffee grinding has become an urgent problem to be solved. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a measurement system and method for the gap between the burrs of a coffee grinder, in order to solve the problem that the lack of accurate means for measuring the gap between the burrs of a coffee grinder in the prior art leads to unstable coffee grinding and preparation quality.

[0006] This invention provides a measurement system for the gap between the blades of a coffee grinder. The system includes a displacement acquisition module, a signal amplification module, a signal conversion module, and a main control unit. The output terminal of the displacement acquisition module is electrically connected to the input terminal of the signal amplification module, the output terminal of the signal amplification module is electrically connected to the input terminal of the signal conversion module, and the output terminal of the signal conversion module is electrically connected to the input terminal of the main control unit. The displacement acquisition module includes a VCP1612 linear position sensor, which generates a first electrical signal when the upper and lower blades of the grinder are relative to each other during the process of acquiring the blade gap distance. The signal amplification module is used to receive the first electrical signal and amplify it to generate the second electrical signal; A signal conversion module is used to receive a second electrical signal and convert it into a digital signal; The main control unit is used to receive digital signals and analyze and calculate the displacement information of the adjustment rod of the grinder blade gap, thereby obtaining the grinder blade gap value.

[0007] Optionally, the signal amplification module includes an SGM8632 operational amplifier; wherein, the +INA terminal of the operational amplifier is electrically connected to the +V1 terminal of the linear position sensor via resistor R23, and the +INA terminal of the operational amplifier is also connected to a 2.5V reference voltage via resistor R21; the -INA terminal of the operational amplifier is electrically connected to the -V1 terminal of the linear position sensor via resistor R25; the +INB terminal of the operational amplifier is electrically connected to the +V2 terminal of the linear position sensor via resistor R24, and the +INB terminal of the operational amplifier is also connected to a 2.5V reference voltage via resistor R22. It is connected to a 2.5V reference voltage; the -INB terminal of the operational amplifier is electrically connected to the -V2 terminal of the linear position sensor through resistor R26; the +Vs terminal of the operational amplifier is connected to a 5V reference voltage, and the +Vs terminal of the operational amplifier is also grounded through capacitor C20; the -Vs terminal of the operational amplifier is grounded; a resistor R27 is connected between the OUTA terminal and the -INA terminal of the operational amplifier, and a capacitor C23 is connected in parallel across the resistor R27; a resistor R28 is connected between the OUTB terminal and the -INB terminal of the operational amplifier, and a capacitor C24 is connected in parallel across the resistor R28.

[0008] Optionally, a first voltage reference chip of model REF3025 is used to provide one 2.5V reference voltage, and a second voltage reference chip of model GM7400 is used to provide a second 2.5V reference voltage.

[0009] Optionally, it also includes a power supply module, which is electrically connected to the displacement acquisition module, signal amplification module, signal conversion module and main control unit to provide operating voltage.

[0010] Optionally, the power supply module includes a 5V input voltage source, a field-effect transistor (FET) Q1, an electrostatic discharge (ESD) surge protection diode D1, capacitors C1, C2, C3, and C4, and a linear regulator. The 5V input voltage source is connected to the drain of FET Q1 and is also grounded through the ESD surge protection diode D1. The gate of FET Q1 is grounded, and the source of FET Q1 is grounded through capacitor C1. A freewheeling diode is connected in parallel between the drain and source of FET Q1. The source of FET Q1 is connected to the VIN terminal of the linear regulator. The VOUT terminal of the linear regulator is connected to one end of capacitor C4, and the GND terminal of the linear regulator is connected to the other end of capacitor C4. Capacitor C3 is connected in parallel across capacitor C4. The VOUT terminal of the linear regulator outputs a 3.3V voltage. The source of FET Q1 is also grounded through capacitor C2.

[0011] Optionally, the signal conversion module includes an ADS1256 A / D conversion module, and the main control unit includes a GD32F303CCT6 MCU chip. The A / D conversion module is electrically connected to the PB13, PB15, PB14, PB10 and PB11 pins of the MCU chip through the SCLK, DIN, DOUT, CS and DRDY pins, respectively.

[0012] Optionally, the main control unit also includes a storage module and a communication module, wherein the storage module is used to store several displacement calculation parameters; the displacement calculation parameters include: the zero point position of the upper and lower cutter heads, the calibration coefficient of the displacement acquisition module, the displacement data conversion formula and / or the mapping relationship between electrical signals and displacement distance; The main control unit transmits the calculated tool head gap distance data to an external display terminal and / or remote control system via a communication module.

[0013] The present invention also provides a method for measuring the burr gap of a coffee grinder, employing the aforementioned measurement system for the burr gap of a coffee grinder, comprising: Adjust the distance between the upper and lower blades of the coffee grinder; The first electrical signal is obtained by a displacement acquisition module installed at the cutter head adjustment rod or the upper and lower cutter heads. The first electrical signal is amplified and filtered to obtain the second electrical signal; The second electrical signal is converted from analog to digital to obtain a digital signal; By combining the calibration coefficient, zero-point position, and digital signal of the displacement acquisition module, the value of the gap between the upper and lower blades of the coffee grinder after the distance is adjusted is calculated.

[0014] Optionally, in the step of calculating the gap between the upper and lower blades of the coffee grinder after adjusting the distance by combining the calibration coefficient, zero-point position, and digital signal from the displacement acquisition module, the formula for calculating the blade gap includes: ; like Then make ;otherwise ; ; In the formula, AD 0′ and AD 1' represents the processed values ​​of two differential voltage signals generated in real time by the linear position sensor during the data acquisition process. α 0 represents the angle value obtained by converting the two differential voltage signals. X This indicates the position of the adjusting lever, corresponding to the cutter head clearance. n Indicates the cycle of motion. p The distance between the magnetic poles is denoted as .

[0015] Optionally, the steps for obtaining the zero-point position of the displacement acquisition module include: Adjust the gap between the upper and lower blades of the coffee grinder until the upper and lower blades are in close contact. Record the first electrical signal generated by the displacement acquisition module during the adjustment. If the operation of reducing the gap between the upper and lower blades of the coffee grinder continues and the first electrical signal remains stable, then the current first electrical signal is determined to be at the zero position.

[0016] The beneficial effects of this invention are: 1. This embodiment provides a measurement system for the blade gap of a coffee grinder. The system includes a displacement acquisition module, a signal amplification module, a signal conversion module, and a main control unit. The output terminal of the displacement acquisition module is electrically connected to the input terminal of the signal amplification module, the output terminal of the signal amplification module is electrically connected to the input terminal of the signal conversion module, and the output terminal of the signal conversion module is electrically connected to the input terminal of the main control unit. The displacement acquisition module includes a VCP1612 linear position sensor, which generates a first electrical signal when the blade gap distance is acquired during the relative displacement of the upper and lower blades of the coffee grinder. The signal amplification module receives the first electrical signal and amplifies it to generate a second electrical signal. The signal conversion module receives the second electrical signal and converts it into a digital signal. The main control unit receives the digital signal and analyzes and calculates the displacement information of the adjustment rod for the blade gap of the coffee grinder, thereby obtaining the blade gap value of the coffee grinder. The high-precision linear position sensor, employing anisotropic magnetoresistive technology, offers higher position detection accuracy compared to traditional Hall effect sensors. The VCP1612 model linear position sensor can operate stably in harsh environments such as oil, dust, and high temperatures, combining excellent reliability and measurement accuracy. When the upper and lower blades of the coffee grinder experience relative displacement, it can accurately acquire the changing distance information between them. Therefore, during the factory zeroing process of the upper and lower blades, the linear position sensor can be zeroed simultaneously to synchronize them. After the grinder is put into use, the absolute distance between the blades can be directly obtained, effectively overcoming the problem of relative gap changes caused by long-term blade wear. This allows for precise quantification of the gap value, thereby improving the precision control of coffee powder grinding and enhancing the quality of the finished product.

[0017] 2. Install the magnetic scale on the component experiencing relative displacement, and install the linear position sensor on the fixed component to minimize malfunctions caused by frequent displacement of circuit components. In a specific embodiment, when the linear position sensor moves relative to the magnetic scale, its detection signal changes, thereby enabling gap measurement.

[0018] 3. The two sets of differential signals output by the linear position sensor are conditioned by an SGM8632 operational amplifier. The amplification gain is configured by an RC circuit, and environmental noise outside the sensor and amplification circuit is effectively filtered out to ensure signal purity.

[0019] 4. The REF3025 primary voltage reference chip is characterized by its small size, controllable cost, and excellent precision, providing a stable reference voltage for high-precision operational amplifiers and ensuring the linearity of signal amplification. The GM7400 precision reference voltage source employs advanced curvature compensation technology, featuring low temperature drift of 3ppm / °C, predictable temperature characteristics, and ±0.04% initial voltage accuracy. It provides a low-drift, low-noise reference voltage for A / D conversion modules, preventing voltage fluctuations from affecting conversion accuracy. Attached Figure Description

[0020] The features and advantages of the invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the drawings: Figure 1 A structural diagram of a system for measuring the gap between the blades of a coffee grinder, according to an embodiment of the present invention, is shown. Figure 2 A schematic diagram of a measurement system for the blade clearance of a coffee grinder is shown in an embodiment of the present invention; Figure 3 The circuit diagram of the displacement acquisition module of a measurement system for the gap between the blades of a coffee grinder is shown in an embodiment of the present invention. Figure 4 This invention illustrates one of the circuit diagrams of a signal amplification module for a coffee grinder blade clearance measurement system according to an embodiment of the present invention; Figure 5 The second circuit diagram of the signal amplification module of a measuring system for the gap between the blades of a coffee grinder is shown in an embodiment of the present invention. Figure 6 This invention illustrates one of the power supply module circuit diagrams for a coffee grinder blade clearance measurement system according to an embodiment of the present invention; Figure 7 The second power supply module circuit diagram of a measuring system for the gap between the blades of a coffee grinder is shown in an embodiment of the present invention; Figure 8 The circuit diagram of a signal conversion module for a coffee grinder blade clearance measurement system according to an embodiment of the present invention is shown. Figure 9 The circuit diagram of the main control unit of a measuring system for the gap between the blades of a coffee grinder is shown in an embodiment of the present invention. Figure 10 A flowchart of a method for measuring the gap between the blades of a coffee grinder, according to an embodiment of the present invention, is shown. Detailed Implementation

[0021] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0022] Example 1 This invention provides a measurement system for the burr gap of a coffee grinder, such as... Figure 1 and Figure 2 As shown, the system includes a displacement acquisition module, a signal amplification module, a signal conversion module, and a main control unit. The output terminal of the displacement acquisition module is electrically connected to the input terminal of the signal amplification module, the output terminal of the signal amplification module is electrically connected to the input terminal of the signal conversion module, and the output terminal of the signal conversion module is electrically connected to the input terminal of the main control unit. The displacement acquisition module includes a VCP1612 linear position sensor, which generates a first electrical signal when the upper and lower blades of the grinder are relative to each other during the process of acquiring the blade gap distance. The signal amplification module is used to receive the first electrical signal and amplify it to generate the second electrical signal; A signal conversion module is used to receive a second electrical signal and convert it into a digital signal; The main control unit is used to receive digital signals and analyze and calculate the displacement information of the adjustment rod of the grinder blade gap, thereby obtaining the grinder blade gap value.

[0023] In this embodiment, a high-precision linear position sensor employing anisotropic magnetoresistive technology offers higher position detection accuracy compared to traditional Hall effect sensors. The VCP1612 linear position sensor can operate stably in harsh working environments such as oil, dust, and high temperatures, exhibiting both excellent reliability and measurement accuracy. When the upper and lower blades of the coffee grinder undergo relative displacement, it can accurately acquire the changing distance information between them. Therefore, during the zeroing process of the upper and lower blades at the factory, the linear position sensor can be zeroed simultaneously to synchronize the two. Subsequently, when the coffee grinder is put into use, the absolute distance between the blades can be directly obtained, effectively overcoming the problem of relative gap changes caused by long-term wear of the blades. This achieves precise quantification of the gap value, thereby improving the precision control of coffee powder grinding and enhancing the quality of the finished product.

[0024] As an optional implementation, the displacement acquisition module also includes a magnetic scale, wherein the magnetic scale is attached to the cutter head gap adjustment rod. During the adjustment of the cutter head gap, the magnetic scale moves up and down with the adjustment rod, and the linear position sensor is fixed on the inner wall of the adjustment chamber opposite to the magnetic scale.

[0025] In this embodiment, the magnetic scale is mounted on the component experiencing relative displacement, while the linear position sensor is mounted on a fixed component to minimize malfunctions caused by frequent displacement of circuit components. In a specific embodiment, when the linear position sensor moves relative to the magnetic scale, its detection signal changes, thereby enabling gap measurement. In a specific embodiment, the linear position sensor is soldered onto a PCB board, which is fixed to the inner wall of the adjustment chamber where the adjustment rod is located. In a specific implementation, the operating end of the adjustment rod is a spring, and the adjustment rod moves vertically up and down during adjustment. Therefore, there is a longitudinal relative displacement between the magnetic scale and the linear position sensor, during which the linear position sensor generates a differential signal.

[0026] As an optional implementation, the signal amplification module includes an SGM8632 operational amplifier; wherein, the +INA terminal of the operational amplifier is electrically connected to the +V1 terminal of the linear position sensor via resistor R23, and the +INA terminal of the operational amplifier is also connected to a 2.5V reference voltage via resistor R21; the -INA terminal of the operational amplifier is electrically connected to the -V1 terminal of the linear position sensor via resistor R25; the +INB terminal of the operational amplifier is electrically connected to the +V2 terminal of the linear position sensor via resistor R24, and the +INB terminal of the operational amplifier is also connected to a 2.5V reference voltage via resistor R25. R22 is connected to a 2.5V reference voltage; the -INB terminal of the operational amplifier is electrically connected to the -V2 terminal of the linear position sensor through resistor R26; the +Vs terminal of the operational amplifier is connected to a 5V reference voltage, and the +Vs terminal of the operational amplifier is also grounded through capacitor C20; the -Vs terminal of the operational amplifier is grounded; a resistor R27 is connected between the OUTA and -INA terminals of the operational amplifier, and a capacitor C23 is connected in parallel across the resistor R27; a resistor R28 is connected between the OUTB and -INB terminals of the operational amplifier, and a capacitor C24 is connected in parallel across the resistor R28.

[0027] In this embodiment, as Figures 3 to 5 As shown, the two sets of differential signals output by the linear position sensor are conditioned by an SGM8632 operational amplifier, the amplification gain is configured by an RC circuit, and environmental noise outside the sensor and amplifier circuit is effectively filtered out to ensure signal purity.

[0028] As an optional implementation, a first voltage reference chip of model REF3025 is used to provide one 2.5V reference voltage, and a second voltage reference chip of model GM7400 is used to provide a second 2.5V reference voltage.

[0029] In this embodiment, the REF3025 first voltage reference chip features small size, controllable cost, and excellent precision, providing a stable reference voltage for the high-precision operational amplifier and ensuring the linearity of signal amplification. The precision reference voltage source GM7400 employs advanced curvature compensation technology, featuring low temperature drift of 3ppm / °C, predictable temperature characteristics, and ±0.04% initial voltage accuracy, providing a low-drift, low-noise reference voltage for the A / D conversion module and preventing voltage fluctuations from affecting conversion accuracy.

[0030] As an optional implementation, it also includes a power supply module, which is electrically connected to the displacement acquisition module, signal amplification module, signal conversion module and main control unit to provide operating voltage.

[0031] As an optional implementation, the power supply module includes a 5V input voltage source, a field-effect transistor (FET) Q1, an electrostatic discharge (ESD) surge protection diode D1, capacitors C1, C2, C3, and C4, and a linear regulator. The 5V input voltage source is connected to the drain of FET Q1 and is also grounded through the ESD surge protection diode D1. The gate of FET Q1 is grounded, and the source of FET Q1 is grounded through capacitor C1. A freewheeling diode is connected in parallel between the drain and source of FET Q1. The source of FET Q1 is connected to the VIN terminal of the linear regulator. The VOUT terminal of the linear regulator is connected to one end of capacitor C4, and the GND terminal of the linear regulator is connected to the other end of capacitor C4. Capacitor C3 is connected in parallel across capacitor C4. The VOUT terminal of the linear regulator outputs a 3.3V voltage. The source of FET Q1 is also grounded through capacitor C2.

[0032] In this embodiment, as Figure 6 and Figure 7 As shown, an AMS1117 linear regulator is set between the connected 5V input voltage source and each module device to provide a stable output voltage for each module device, while also ensuring the stability of the reference voltage. In addition, the PMOS field-effect transistor Q1 also has a reverse connection protection function.

[0033] As an optional implementation, the signal conversion module includes an ADS1256 A / D conversion module, and the main control unit includes a GD32F303CCT6 MCU chip. The A / D conversion module is electrically connected to the PB13, PB15, PB14, PB10 and PB11 pins of the MCU chip through the SCLK, DIN, DOUT, CS and DRDY pins, respectively.

[0034] like Figure 8As shown, the ADS1256 chip is used, ensuring 24-bit no-miss code at all data rates and PGA settings, with a maximum nonlinearity error of only ±0.0010%. At low speeds, it achieves a noise-immune resolution of up to 23 bits, and at a sampling rate of 1.45kHz, the effective number of bits (ENOB) reaches 21.3 bits, accurately distinguishing nanovolt-level voltage changes and perfectly adapting to the conversion requirements of weak sensor signals. In this embodiment, the A / D conversion module converts the conditioned analog signal into a digital signal. Its high resolution and low nonlinearity error characteristics ensure that the electrical signal corresponding to minute gap changes can be accurately captured. In a specific embodiment, a ferrite bead is used for analog-to-digital isolation between the analog and digital circuits, reducing the influence of the digital circuit on the analog circuit and improving acquisition accuracy.

[0035] As an optional implementation, the main control unit also includes a storage module and a communication module, wherein the storage module is used to store several displacement calculation parameters; the displacement calculation parameters include: the zero point position of the upper and lower cutter heads, the calibration coefficient of the displacement acquisition module, the displacement data conversion formula and / or the mapping relationship between electrical signals and displacement distance; The main control unit transmits the calculated tool head gap distance data to an external display terminal and / or remote control system via a communication module.

[0036] In this embodiment, as Figure 9 As shown, the main control unit uses a GD32F303CCT6 MCU chip. The storage module is mainly used to store key information such as the correspondence table between the scale and the gap, the zero-point position data after zeroing calibration, and the calibration coefficients of the A / D conversion module, ensuring long-term stable data storage. The MCU chip receives the digital signal after A / D conversion and, combined with the calibration coefficients, zero-point position, and other data stored in the storage module, calculates the absolute value of the tool head gap using a built-in algorithm.

[0037] The calibration coefficients of the displacement acquisition module, specifically the calibration coefficients of the linear position sensor, need to be calibrated, set, updated, and stored in the storage module before leaving the factory due to the influence of the actual parameters of capacitance and resistance. If the sensor needs to be debugged, repaired, or replaced in the future, the calibration coefficients also need to be updated and overwritten.

[0038] The process of obtaining the displacement data conversion formula includes: obtaining the displacement distance of the adjusting rod, the corresponding differential signal of the linear position sensor and the actual cutter head clearance during several cutter head clearance processes, and fitting the linear relationship between the three.

[0039] The specific calculation process is as follows: Move the VCP161X linear position sensor a certain distance on the magnetic grating, for example, with the maximum travel as the upper limit. Acquire two signals through the ADC, and obtain the maximum values ​​max(AD0), max(AD1), and minimum values ​​min(AD0), min(AD1) of the two signals respectively. Then calculate the compensation values ​​for the two signals respectively: ; ; The above compensation values ​​are stored in the storage module for later use.

[0040] For the outputs AD0 and AD1 at any given position, the following calculations are performed: ; ; Radius conversion using the atan2 function: ; Angle conversion: The corresponding angle range is (-90°, 90°). If... Then make Correct the angle.

[0041] According to the angle α Calculate position X: First, calculate the position X0 within one period: ; In the formula, p is the magnetic pole spacing. For example, a 2+2mm magnetic grating corresponds to p=2mm, and a 5+5mm magnetic grating corresponds to p=5mm.

[0042] The number of cycles n throughout the motion is accumulated, and finally, the cutter head gap position information X, which changes in the same way as the adjustment distance of the adjusting rod, is obtained: ; If the calculated angle α If the angle increases periodically from 0 to 180°, it is considered positive motion; if the angle... α If the period decreases from 180° to 0, then it is a reverse motion.

[0043] The MCU updates the calculated gap value to the storage module in real time, and encapsulates the data according to the MODBUS protocol format. The data is then transmitted to an external display terminal or control system via the 485 communication module (MAX3485) to realize intuitive display and remote monitoring of the gap value.

[0044] Example 2 This invention also provides a method for measuring the burr gap of a coffee grinder, using a burr gap measurement system from Embodiment 1, such as... Figure 10 As shown, it includes: Step S10: Adjust the distance between the upper and lower blades of the coffee grinder.

[0045] Step S20: Obtain the first electrical signal through the displacement acquisition module installed at the cutter head adjustment rod or the upper and lower cutter heads.

[0046] Step S30: Amplify and filter the first electrical signal to obtain the second electrical signal.

[0047] Step S40: The second electrical signal is converted from analog to digital to obtain a digital signal.

[0048] Step S50: Combining the calibration coefficient, zero position, and digital signal of the displacement acquisition module, the value of the gap between the upper and lower blades of the grinder after adjusting the distance is calculated.

[0049] In this embodiment, a high-precision linear position sensor employing anisotropic magnetoresistive technology offers higher position detection accuracy compared to traditional Hall effect sensors. The VCP1612 linear position sensor can operate stably in harsh working environments such as oil, dust, and high temperatures, exhibiting both excellent reliability and measurement accuracy. When the upper and lower blades of the coffee grinder undergo relative displacement, it can accurately acquire the changing distance information between them. Therefore, during the zeroing process of the upper and lower blades at the factory, the linear position sensor can be zeroed simultaneously to synchronize the two. Subsequently, when the coffee grinder is put into use, the absolute distance between the blades can be directly obtained, effectively overcoming the problem of relative gap changes caused by long-term wear of the blades. This achieves precise quantification of the gap value, thereby improving the precision control of coffee powder grinding and enhancing the quality of the finished product.

[0050] As an optional implementation, the steps for obtaining the zero-point position of the displacement acquisition module include: Adjust the gap between the upper and lower blades of the coffee grinder until the upper and lower blades are in close contact. Record the first electrical signal generated by the displacement acquisition module during the adjustment. If the operation of reducing the gap between the upper and lower blades of the coffee grinder continues and the first electrical signal remains stable, then the current first electrical signal is determined to be at the zero position.

[0051] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A measurement system for the gap between the blades of a coffee grinder, characterized in that, The system includes a displacement acquisition module, a signal amplification module, a signal conversion module, and a main control unit. The output terminal of the displacement acquisition module is electrically connected to the input terminal of the signal amplification module, the output terminal of the signal amplification module is electrically connected to the input terminal of the signal conversion module, and the output terminal of the signal conversion module is electrically connected to the input terminal of the main control unit. The displacement acquisition module includes a VCP1612 linear position sensor, which generates a first electrical signal when the upper and lower blades of the grinder are relative to each other during the process of acquiring the blade gap distance. The signal amplification module is used to receive the first electrical signal and amplify it to generate a second electrical signal; The signal conversion module is used to receive the second electrical signal and convert it into a digital signal; The main control unit is used to receive the digital signal and analyze and calculate the displacement information of the adjustment rod of the grinder blade gap, thereby obtaining the grinder blade gap value.

2. The measuring system for the gap between the blades of a coffee grinder according to claim 1, characterized in that, The signal amplification module includes an SGM8632 operational amplifier; wherein, the +INA terminal of the operational amplifier is electrically connected to the +V1 terminal of the linear position sensor via resistor R23, and the +INA terminal of the operational amplifier is also connected to a 2.5V reference voltage via resistor R21; the -INA terminal of the operational amplifier is electrically connected to the -V1 terminal of the linear position sensor via resistor R25; the +INB terminal of the operational amplifier is electrically connected to the +V2 terminal of the linear position sensor via resistor R24, and the +INB terminal of the operational amplifier is also connected to a 2.5V reference voltage via resistor R22. A 0.5V reference voltage is connected; the -INB terminal of the operational amplifier is electrically connected to the -V2 terminal of the linear position sensor through resistor R26; the +Vs terminal of the operational amplifier is connected to a 5V reference voltage, and the +Vs terminal of the operational amplifier is also grounded through capacitor C20; the -Vs terminal of the operational amplifier is grounded; a resistor R27 is connected between the OUTA terminal and the -INA terminal of the operational amplifier, and a capacitor C23 is connected in parallel across the resistor R27; a resistor R28 is connected between the OUTB terminal and the -INB terminal of the operational amplifier, and a capacitor C24 is connected in parallel across the resistor R28.

3. The measuring system for the gap between the blades of a coffee grinder according to claim 2, characterized in that, A first voltage reference chip (REF3025) provides one 2.5V reference voltage, and a second voltage reference chip (GM7400) provides the second 2.5V reference voltage.

4. The measuring system for the gap between the blades of a coffee grinder according to claim 1, characterized in that, Also includes: The power supply module is electrically connected to the displacement acquisition module, the signal amplification module, the signal conversion module, and the main control unit to provide operating voltage.

5. The measuring system for the gap between the blades of a coffee grinder according to claim 4, characterized in that, The power supply module includes a 5V input voltage source, a field-effect transistor (FET) Q1, an electrostatic discharge (ESD) surge protection diode D1, capacitors C1, C2, C3, and C4, and a linear regulator. The 5V input voltage source is connected to the drain of FET Q1 and is also grounded through the ESD surge protection diode D1. The gate of FET Q1 is grounded, and the source of FET Q1 is grounded through capacitor C1. A freewheeling diode is connected in parallel between the drain and source of FET Q1. The source of FET Q1 is connected to the VIN terminal of the linear regulator. The VOUT terminal of the linear regulator is connected to one end of capacitor C4, and the GND terminal of the linear regulator is connected to the other end of capacitor C4. Capacitor C3 is connected in parallel across capacitor C4. The VOUT terminal of the linear regulator outputs a 3.3V voltage. The source of FET Q1 is also grounded through capacitor C2.

6. The measuring system for the gap between the blades of a coffee grinder according to claim 1, characterized in that, The signal conversion module includes an ADS1256 A / D conversion module, and the main control unit includes a GD32F303CCT6 MCU chip. The A / D conversion module is electrically connected to the PB13, PB15, PB14, PB10, and PB11 pins of the MCU chip via the SCLK, DIN, DOUT, CS, and DRDY pins, respectively.

7. The measuring system for the gap between the blades of a coffee grinder according to claim 1, characterized in that, The main control unit also includes a storage module and a communication module, wherein the storage module is used to store several displacement calculation parameters; the displacement calculation parameters include: the zero point position of the upper and lower cutter heads, the calibration coefficient of the displacement acquisition module, the displacement data conversion formula and / or the mapping relationship between electrical signals and displacement distance; The main control unit transmits the calculated cutter head gap distance data to an external display terminal and / or remote control system via a communication module.

8. A method for measuring the gap between the blades of a coffee grinder, employing the measuring system for measuring the gap between the blades of a coffee grinder as described in any one of claims 1 to 7, characterized in that, include: Adjust the distance between the upper and lower blades of the coffee grinder; The first electrical signal is obtained by a displacement acquisition module installed at the cutter head adjustment rod or the upper and lower cutter heads. The first electrical signal is amplified and filtered to obtain the second electrical signal; The second electrical signal is converted from analog to digital to obtain a digital signal; By combining the calibration coefficient of the displacement acquisition module, the zero point position, and the digital signal, the value of the gap between the upper and lower blades of the coffee grinder after the distance is adjusted is calculated.

9. The method for measuring the gap between the blades of a coffee grinder according to claim 8, characterized in that, In the step of calculating the gap between the upper and lower blades of the coffee grinder after adjusting the distance, by combining the calibration coefficient of the displacement acquisition module, the zero-point position, and the digital signal, the formula for calculating the blade gap is as follows: include: ； like Then make ;otherwise ; ； In the formula, AD 0′ and AD 1' represents the processed values ​​of two differential voltage signals generated in real time by the linear position sensor during the data acquisition process. α 0 represents the angle value obtained by converting the two differential voltage signals. X This indicates the position of the adjusting lever, corresponding to the cutter head clearance. n Indicates the cycle of motion. p The distance between the magnetic poles is denoted as .

10. The method for measuring the gap between the blades of a coffee grinder according to claim 8, characterized in that, The steps for obtaining the zero-point position of the displacement acquisition module include: Adjust the gap between the upper and lower blades of the coffee grinder until the upper blade and the lower blade are in close contact. Record the first electrical signal generated by the displacement acquisition module during the adjustment. If the operation of reducing the gap between the upper and lower blades of the coffee grinder continues and the first electrical signal remains stable, then the current first electrical signal is determined to correspond to the zero point position.

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