A mixer with good mixing effect

Abstract

This invention relates to the field of food preparation technology, specifically to a blender with excellent mixing effect. The blender includes a mixing cup, a drive motor, a control module, and a blade assembly mounted on the output shaft of the drive motor. The blade assembly includes a first blade and a second blade stacked together. The first blade has an upwardly curved stirring blade, and the second blade has a horizontal grinding blade with serrated cutting edges. The control module includes a current sampling unit, a calculation unit, and a frequency conversion drive unit. The control module is used to establish a mapping relationship between the specific physical shape of the blades and the waveform characteristics of the motor current based on the operating state of the drive motor, and to adjust the output commands to the drive motor in real time. The blender provided by this invention achieves precise quantification of the hardness and viscosity of ingredients by establishing a mapping relationship between the specific physical shape of the blades and the waveform characteristics of the motor current, thereby enabling intelligent control of the blender.

Description

Technical Field

[0001] This invention relates to the field of food preparation technology, and more specifically to a mixer with good mixing effect. Background Technology

[0002] With the improvement of living standards, food processors (such as blenders and mixers) have become common kitchen appliances in households. Traditional blenders typically use knobs or buttons to select preset fixed speeds (such as high speed, low speed, and pulse) or fixed-duration programs (such as soy milk mode and smoothie mode). However, existing blender technology has the following main technical problems in practical applications:

[0003] Lack of load recognition capability and low crushing efficiency: Existing technology cannot sense the state of the food inside the cup in real time. For example, when processing hard ice cubes, if the rotation speed is too low, it will not be able to crush them, while if the rotation speed is too high, the ice cubes will easily be thrown to the cup wall and not be crushed. When processing viscous ingredients, due to the lack of sensing of fluid viscosity, blindly rotating at high speed can easily cause vacuum holes to form around the blades, causing the blades to spin idly and fail to stir effectively.

[0004] The control strategy is disconnected from the blade structure: Existing control programs are often generic and not optimized for specific blade physical shapes. For example, serrated blades generate specific impact reaction forces when cutting hard objects, while upward-pointing blades generate specific axial resistance when stirring fluids. Existing control systems typically ignore this rich physical feedback information from the mechanical structure, treating current only as a simple overload protection indicator, thus wasting the possibility of inferring the state of the food through current characteristics.

[0005] Noise and heat issues: Since it cannot determine whether the ingredients have been completely pulverized, the machine often continues to run at high speed even when the ingredients are already finely pulverized. This not only causes unnecessary noise and motor heat, but also shortens the product's lifespan.

[0006] Therefore, there is an urgent need for an intelligent mixer that can accurately identify the state of ingredients and adaptively adjust the control strategy by deeply analyzing the load characteristics of the blades. Summary of the Invention

[0007] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide a mixer with good mixing effect. This mixer achieves precise quantification of the hardness and viscosity of food by establishing a mapping relationship between the specific physical shape of the blade and the waveform characteristics of the motor current, thereby enabling intelligent control of the mixer.

[0008] This invention is achieved through the following technical solution: In a first aspect, the present invention discloses a mixer with good mixing effect, which includes a mixing cup, a drive motor, a control module and a blade assembly mounted on the output shaft of the drive motor. The blade assembly includes a first blade and a second blade stacked together. The first blade is provided with an upwardly bent upward stirring blade, and the second blade is provided with a horizontal crushing blade with a serrated cutting edge. The control module includes a current sampling unit, a computing unit, and a frequency conversion drive unit. The control module is used to establish a mapping relationship between the specific physical shape of the blade and the current waveform characteristics of the motor according to the operating state of the drive motor, and to adjust the output commands to the drive motor in real time.

[0009] In conjunction with the first aspect, the control module is further configured to perform the following steps: S100. The variable frequency drive unit controls the drive motor to operate at a preset initial speed. During operation, the real-time motor phase current signal sequence is acquired through the current sampling unit. ; S200. The arithmetic unit processes the current signal sequence. Time-domain and frequency-domain analyses were performed to calculate the impact characteristic index characterizing the hardness of the food. And fluid resistance, which characterizes the viscosity of food ingredients. ; S300. The computing unit will impact the characteristic index. and fluid resistance index Substituting the preset multidimensional coupling control function, the optimal target rotation speed under the current food condition is calculated. ; S400. Variable frequency drive unit based on optimal target speed. generate The control signal adjusts the motor speed until... Once the decay rate drops below the preset threshold, the grinding process begins.

[0010] In conjunction with the first aspect, further, in step S200, the impact characteristic index is calculated using the instantaneous high-frequency pulse current characteristics generated by the serrated cutting edge of the second blade when impacting hard food. ; The length of the operation unit is Current sampling points within the time window The kurtosis of the current signal is calculated using a fourth-order central moment algorithm, and this is used as the impact characteristic index. The calculation formula is as follows:

[0011] in, For the first The instantaneous current value at each sampling point The current is the average value within this time window, and constant 3 is the kurtosis reference value for the normal distribution.

[0012] In conjunction with the first aspect, further, in step S200, the fluid resistance index is calculated using the nonlinear relationship between the axial pumping resistance generated when the upward stirring blades rotate in the fluid and the fluid viscosity. ; The computational unit constructs an observer model based on the extended Kalman filter to calculate the fluid drag exponent. The state estimation algorithm is as follows:

[0013] in, For the first Estimated load torque at time, The moment of inertia of the motor and cutting tool system. The coefficient of mechanical friction, The current mechanical angular velocity, For the first The fluid resistance index at time t. The shape factor is related to the hydrodynamic characteristics of the upward stirring blades, and its value ranges from 1.8 to 2.2.

[0014] In conjunction with the first aspect, further, in step S300, the optimal target rotational speed is calculated. The specific process is as follows: Based on the impact characteristic index calculated in real time The speed is dynamically adjusted, and the calculation formula is as follows:

[0015] in, The set maximum cell-wall breaking speed. To maintain the lowest possible speed for the minimum cycle, To adjust the sensitivity coefficient, The kurtosis threshold is used to characterize the critical point of food breakage.

[0016] In conjunction with the first aspect, the control module further includes step S500: when the fluid resistance index... The first derivative is less than the preset negative threshold At that time, it was determined that a vacuum cavity was formed around the blade; At this time, the drive motor is controlled to perform pulse braking, and the braking torque... The following formula is used for the calculation:

[0017] in, This is the maximum braking torque of the drive motor. The attenuation coefficient is... This represents the oscillation frequency.

[0018] In a second aspect, the present invention discloses an electronic device comprising a memory, a control module, and a computer program stored in the memory and executable on the control module, wherein the control module executes the computer program to perform the steps described in any of the preceding claims.

[0019] Thirdly, the present invention discloses a computer-readable storage medium having a computer program stored thereon, the program being executed by a control module to implement the steps described in any of the preceding claims.

[0020] The beneficial effects of this invention are: The present invention provides a mixer with good mixing effect. By setting up a drive motor, a blade assembly and a control module, the control module acquires the state parameters when the drive motor drives the blade assembly, establishes a mapping relationship between the specific physical shape of the blade and the waveform characteristics of the motor current, realizes the precise quantification of the hardness and viscosity of the food, and then performs intelligent closed-loop control. It can also effectively solve the problems of noise and heat generation, and improve the service life of the mixer. Attached Figure Description

[0021] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0022] Figure 1 This is an exploded structural diagram of a mixer according to an embodiment of the present invention.

[0023] Figure 2 This is a flowchart illustrating the execution steps of the control module according to an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of a storage medium provided in an embodiment of the present invention.

[0026] Figure Labels Stirring cup--101, drive motor--102, blade assembly--103, first blade--104, second blade--105. Detailed Implementation

[0027] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] Example 1 like Figure 1 As shown, this embodiment discloses a mixer with good mixing effect, characterized in that it includes a mixing cup 101, a drive motor 102, a control module, and a cutter assembly 103 mounted on the output shaft of the drive motor 102. The cutter assembly 103 includes a first blade 104 and a second blade 105 stacked together. The first blade 104 is provided with an upwardly bent upward stirring blade, and the second blade 105 is provided with a horizontal crushing blade with a serrated cutting edge. The control module includes a current sampling unit, a calculation unit, and a frequency conversion drive unit. The control module is used to establish a mapping relationship between the specific physical shape of the blade and the waveform characteristics of the motor current according to the operating state of the drive motor 102, and to adjust the output commands to the drive motor 102 in real time.

[0031] Specifically, the first blade 104 has stirring blades that extend outward from the center and bend upward at a large angle, with the tips of the blades curving upward relative to the horizontal plane at an angle of [missing information]. The preferred angle is 60° to 80°. The hydrodynamic characteristics of this structure are as follows: when the rotational speed is constant, the axial pumping resistance it generates has a significant positive nonlinear relationship with the viscosity of the fluid.

[0032] The second blade 105 has shredding blades extending radially outward from the center, wherein at least one blade has a continuous serrated cutting edge at its leading edge. The mechanical characteristics of this structure are that when cutting brittle and hard materials such as ice and bone, the contact point between the serrations and the material will experience high-frequency intermittent impacts, resulting in microsecond-level drastic fluctuations in the motor load torque.

[0033] Example 2 like Figure 2 As shown, the control module in this embodiment is used to perform the following steps S100-S400: S100. The variable frequency drive unit controls the drive motor 102 to operate at a preset initial speed. During operation, the real-time motor phase current signal sequence is acquired through the current sampling unit. .

[0034] In step S100, The speed range is set to 3000 rpm to 5000 rpm, which falls within the optimal detection zone. If the speed is too low (<1000 rpm), the momentum of the serrated edge impacting the hard object is insufficient, resulting in a weak impact current signal and low signal-to-noise ratio. If the speed is too high (>10,000 rpm), the fluid is prone to instantaneous turbulence or cavitation, leading to excessive load current fluctuations that mask the true physical characteristics. At this speed, the control module activates the current sampling unit to... Frequency acquisition of continuous phase current signal sequences .

[0035] S200. The arithmetic unit processes the current signal sequence. Time-domain and frequency-domain analyses were performed to calculate the impact characteristic index characterizing the hardness of the food. And fluid resistance, which characterizes the viscosity of food ingredients. .

[0036] In step S200, the multidimensional feature decoupling and extraction stage control module processes the acquired current signal sequence in real time. Through time-domain statistical analysis and frequency-domain filtering, the single current signal is decoupled into two independent physical dimension indicators.

[0037] Among them, the impact characteristic index The index, used to characterize the solid hardness of food, is obtained by extracting higher-order statistics from the current waveform. The specific algorithm will be detailed in subsequent embodiments. The higher the index, the more intense the impact between the blade teeth and the hard object.

[0038] Fluid resistance index The viscosity index is used to characterize the fluid viscosity of food ingredients. This index is obtained by removing the inertia term from the observer model; the specific algorithm will be detailed in subsequent embodiments. The higher the index, the greater the viscous shear resistance experienced by the upward-moving blade.

[0039] S300. The computing unit will impact the characteristic index. and fluid resistance index Substituting the preset multidimensional coupling control function, the optimal target rotation speed under the current food condition is calculated. .

[0040] In step S300, the control function follows the following dynamic adjustment strategy: Strategy 1 (Hard Object Blending Mode): When detected At that time, it was determined to be the initial stage of cell wall breaking, at which point regardless of Regardless of the numerical value, the system prioritizes outputting high speed, utilizing the high-speed kinetic energy of the serrated blades to crush hard objects; Strategy 2 (Viscous Stirring Mode): When detected and When the system determines that the mixture is a viscous material, it automatically limits the maximum speed and increases the current output to increase torque, preventing the motor from overheating or stalling. Strategy 3 (Refined Emulsification Mode): When It decays exponentially over time and approaches zero, and When the system stabilizes, it is determined that the hard object has been completely crushed. At this point, the system enters the fine grinding stage, and the rotation speed is smoothly adjusted to a medium-high level for finer processing.

[0041] S400. Variable frequency drive unit based on optimal target speed. generate The control signal adjusts the motor speed until... Once the decay rate drops below the preset threshold, the grinding process begins.

[0042] In step S400, when the system detects If the current waveform remains below the preset fine threshold for a continuous period of time (i.e., the current waveform is close to a pure sine wave with no noise impact), and the user has selected the smart mode, the system will automatically execute the shutdown procedure and end the work, thus avoiding the huge noise and ineffective energy consumption generated by traditional machines that continue to run at high speed after the food has been processed.

[0043] Specifically, in step S200, the impact characteristic index is calculated using the instantaneous high-frequency pulse current characteristics generated by the serrated cutting edge of the second blade 105 when it impacts hard food. ; The length of the operation unit is Current sampling points within the time window The kurtosis of the current signal is calculated using a fourth-order central moment algorithm, and this is used as the impact characteristic index. The calculation formula is as follows:

[0044] in, For the first The instantaneous current value at each sampling point The current is the average value within this time window, and constant 3 is the kurtosis reference value for the normal distribution.

[0045] This embodiment will describe in detail the impact characteristic index mentioned in step S200 of the above steps. The calculation process involves using the kurtosis index in statistics to quantify the non-Gaussian current pulse generated when the second blade 105 collides with the food.

[0046] Take the motor current waveform under different food processing conditions as an example.

[0047] Under operating condition A (soft ingredients / no load), the motor load is stable, and the current waveform is as follows: It is approximately a standard sine wave (or contains a small amount of Gaussian white noise), and its amplitude distribution conforms to the characteristics of a normal distribution.

[0048] In Condition B (hard ingredients / cell wall blending), when the serrated cutting edge of the second blade 105 cuts brittle and hard materials such as ice and bone at high speed, a high-frequency rigid collision occurs between the blade and the material. Microscopically, this collision manifests as instantaneous deceleration and a sudden torque change in the cutting head, resulting in the superposition of several needle-like pulses with extremely high amplitude and extremely short duration onto the sinusoidal fundamental wave of the current waveform. These pulses cause a significant thick tail characteristic in the current amplitude distribution.

[0049] The current sampling unit of the control module uses a sampling frequency The motor phase current is continuously acquired. To ensure real-time performance, the algorithm employs a sliding time window mechanism, with a window length set to [value missing]. (For example Each sampling point corresponds to approximately 25ms of duration. In each calculation cycle, the control module reads the sampling sequence within the current window. .

[0050] To eliminate the influence of the motor's fundamental current (DC component or low-frequency sinusoidal component) on the calculation, the mean (first moment) within the window is first calculated:

[0051] Subsequently, the second-order central moment (i.e., variance) is calculated to characterize the average fluctuation of the current energy:

[0052] Next, the fourth central moment is calculated, an index that is highly sensitive to outliers far from the mean:

[0053] Finally, the normalized kurtosis is calculated according to Fisher's definition and used as the impact characteristic index. :

[0054] Since the theoretical kurtosis of a standard sine wave or Gaussian noise is 3, subtracting 3 from the formula is to zero out the reference point; when processing water, juice, or idling, the current approximates a normal distribution. When processing ice, due to the presence of numerous outlier spike pulses, molecules... It will grow exponentially, leading to The value increases sharply (in practice, it is usually between 5 and 15).

[0055] The control module has a preset hardness threshold. (For example, setting) ).like The system determines that the current blade is cutting a high-hardness material, classifying it as a cell-wall breaking state; if It fell from its high and stabilized at... The system then determines that the hard object has been crushed and is in a fine-grinding state.

[0056] Compared to traditional current amplitude (Peak) detection or root mean square (RMS) detection, this embodiment uses... The indicator has extremely strong anti-interference ability.

[0057] For example, when a mixer is processing high-viscosity dough, the RMS current is large, but the waveform is smooth. It remains very low (close to 0). This allows the system to accurately distinguish between heavy loads (sticky) and heavy impacts (hard), thus avoiding the accidental triggering of the ice-crushing mode during dough mixing, which could cause the motor to overheat.

[0058] Specifically, in step S200, the fluid resistance index is calculated using the nonlinear relationship between the axial pumping resistance generated by the upward stirring blades rotating in the fluid and the fluid viscosity. ; The computational unit constructs an observer model based on the extended Kalman filter to calculate the fluid drag exponent. The state estimation algorithm is as follows:

[0059] in, For the first Estimated load torque at time, The moment of inertia of the motor and cutting tool system. The coefficient of mechanical friction, The current mechanical angular velocity, For the first The fluid resistance index at time t. The shape factor is related to the hydrodynamic characteristics of the upward stirring blades, and its value ranges from 1.8 to 2.2.

[0060] This embodiment details the fluid resistance index described in step S200 above. The calculation process is described. This algorithm utilizes the characteristic of the first blade 104 rotating in the fluid and employs an extended Kalman filter algorithm to achieve real-time observation of the viscosity of the food.

[0061] In the tool assembly 103 of this embodiment, the first blade 104 has a significant upward angle (preferably 60°-80°). According to the principles of fluid mechanics, when it rotates in a fluid, it mainly bears viscous shear resistance and differential pressure resistance.

[0062] The kinematic equations of the mixer's power system can be expressed as follows:

[0063] in, The total moment of inertia of the motor rotor and the tool assembly 103 (unit: ), which are fixed constants; Mechanical angular velocity (unit: ); Electromagnetic torque output by the motor (unit: ), and current Proportional, that is ; The mechanical viscous friction coefficient of the system (bearing friction, etc., unit: ); This is the fluid load resistance torque experienced by the blade.

[0064] For the specific upward-lifting blade structure in this embodiment, its load resistance torque With rotational speed and the viscosity characteristics of food ingredients The following nonlinear relationship exists between them:

[0065] in, The shape factor is a dimensionless parameter related to the blade area, angle of attack, and fluid Reynolds number of the first blade 104. For the specific blade structure described in this embodiment, The value ranges from 1.8 to 2.2, and in this embodiment, the preferred value is 2.1; The fluid resistance index, as defined in this embodiment, eliminates the influence of rotational speed and purely characterizes the physical viscosity of the food.

[0066] Because the above system contains nonlinear terms ( )and Since it cannot be directly measured, this embodiment designs the following EKF algorithm for state estimation.

[0067] Step 1: Constructing the state equations Selecting the system state variable vector Discretize the continuous model (sampling period is 10 ... ), thus obtaining the state transition equation:

[0068] Assuming that within an extremely short sampling period, the viscosity of the food... Treat as a constant Step 2: The processing unit of the control module performs the following calculations in each control cycle. Estimate the prior state of the current time step based on the state of the previous time step. For nonlinear terms Perform linearization and calculate the state transition matrix. :

[0069] Read the measured value from the speed sensor. Calculate Kalman gain The prior state is corrected using measurement residuals, and the optimal estimate is finally obtained. .

[0070] Using the above algorithm, the control module outputs in real time. .

[0071] Scenario A (Dilute Liquid): If If the substance is determined to be water or clear juice, the motor is allowed to accelerate to the highest gear.

[0072] Scene B (Thick Fluid): If the substance is identified as sesame paste or dough, the maximum speed is limited to below 3,000 rpm, and the current setting is increased to output a constant high torque, preventing the motor from overheating or sucking in air due to overload.

[0073] Traditional blenders rely solely on current to determine load. When the motor accelerates rapidly, the current becomes very high (to provide acceleration), which can cause the machine to misinterpret the food as being too sticky and incorrectly reduce the speed. This embodiment uses a mathematical model to accurately subtract inertial torque. and friction torque This allows the machine to accurately extract pure fluid resistance. This enables it to accurately perceive the true state of the food even during dynamic processes of acceleration and deceleration.

[0074] Specifically, in step S300, the optimal target rotational speed is calculated. The specific process is as follows: Based on the impact characteristic index calculated in real time The speed is dynamically adjusted, and the calculation formula is as follows:

[0075] in, The set maximum cell-wall breaking speed. To maintain the lowest possible speed for the minimum cycle, To adjust the sensitivity coefficient, The kurtosis threshold is used to characterize the critical point of food breakage.

[0076] This embodiment details the optimal target rotational speed described in step S300 above. The calculation process is as follows. The control module uses a variant of the Sigmoid function to construct a nonlinear controller to solve the problems of sudden speed changes and oscillations in traditional stepped speed regulation.

[0077] The control module calculates the impact characteristic index in real time. The target speed of the motor is calculated using the following formula:

[0078] To enable those skilled in the art to better understand this scheme, the parameters are explained below with reference to specific experimental data: The maximum blending speed is generally set at 22,000 rpm, which is the upper limit of the safe speed of the motor under rated load and is used to process the hardest ingredients. The minimum sustaining speed is generally set to 4,000 rpm, which is the minimum speed to ensure that the fluid can form a basic circulation and the motor does not overheat. The kurtosis threshold is set to 4.5. This value is the inflection point of the system. At that time, the function output is exactly at the midpoint of the rotation speed range. This threshold was calibrated through a large number of experiments and corresponds to the current characteristics when the ice has been broken into particles with a diameter of about 5 mm. This is the sensitivity coefficient, typically set to 2.0, representing the coefficient that controls the slope of the middle segment of the S-curve. The larger the value, the steeper the curve, and the more sensitive the system is to changes in hardness (manifested as switching characteristics). The flatter the curve, the smoother the speed change. A value of 2.0 balances response speed and smoothness.

[0079] The control strategy performs as follows in practice: Phase A: Low-noise stable region ( ) When the main ingredients are liquid or soft fruit, the calculated It is usually between 0 and 2. It is a huge positive number, the denominator is extremely large, and the entire fractional term approaches 0. The machine automatically maintains low-speed, quiet operation, avoiding high-noise idling.

[0080] Phase B: Linear Sensitive Region ( ) When the ingredients are in a semi-crushed state It fluctuates between 3 and 6, at which point the function is in the linear ascending segment of the S-shaped curve. The rotation speed adjusts linearly with minute changes in hardness; if a small residual ice particle is detected... (Slightly increase), the rotation speed is immediately increased proportionally for crushing; after crushing ( (Slight decrease), and the speed immediately drops back. This mechanism enables the distribution of kinetic energy on demand.

[0081] Phase C: Full-speed saturation zone ( ) When throwing in large, hard objects initially It could surge to 10 or even 20 in an instant, at which point the exponent approaches 0 and the denominator approaches 1. The system outputs full power to ensure that cell wall breaking is completed in the shortest possible time.

[0082] Although this embodiment primarily describes the dominant role of hardness in rotational speed, in actual embodiments, a fluid resistance index is also introduced to protect the motor. As a safety correction factor.

[0083] The final speed command issued is:

[0084] Where the correction function The logic is: when detected If the speed is too high, the maximum speed will be forcibly limited to prevent the motor from stalling due to overcurrent.

[0085] Compared to traditional PID control or tiered control, the Sigmoid control strategy adopted in this embodiment has the following advantages: Superior sound quality: The speed change is continuous and smooth, eliminating the fluctuating step noise common in traditional blenders; High robustness: Even if there are small noise fluctuations in the current signal, the saturation characteristics at both ends of the Sigmoid function will not cause erroneous speed operation; Adaptive endpoint determination: When the ingredients are completely pulverized, The speed naturally drops to a low value, and the rotation speed automatically decreases. Users can achieve the best pulverizing effect without manual intervention.

[0086] Specifically, the steps performed by the control module further include step S500: when the fluid resistance index The first derivative is less than the preset negative threshold At that time, it was determined that a vacuum cavity was formed around the blade; At this time, the drive motor 102 is controlled to perform pulse braking, and the braking torque... The following formula is used for the calculation:

[0087] in, This is the maximum braking torque of the drive motor 102. The attenuation coefficient is... This represents the oscillation frequency.

[0088] This embodiment details the abnormal handling process described in step S400 above. In response to the air suction phenomenon that is easily generated when the large-angle upward structure of the first blade 104 is processing high-viscosity non-Newtonian fluids, this embodiment proposes a solution based on resistance derivative detection and damped oscillation braking.

[0089] The control module calculates the fluid resistance index. Based on this, we further calculate its first derivative (or difference) with respect to time:

[0090] The control module has a preset air suction detection threshold. ( ).

[0091] like This indicates that the resistance change is stable or decreases slowly, which is a normal stirring process; like (For example This means that the resistance drops precipitously in a very short time, and the current rotation speed is high. The system determines that a vacuum cavity has been formed around the blade and enters the vacuum protection mode.

[0092] Once the air-sucking protection is triggered, the control module immediately cuts off the normal drive signal and applies a reverse pulse braking torque to the motor windings. To utilize fluid inertia to break the vacuum layer while avoiding excessive motor reversal or mechanical shock, the braking torque follows an exponentially decaying oscillating function:

[0093] This action lasts for an extremely short time (usually less than 500ms), among which, The maximum braking amplitude is set to 1.5 to 2 times the rated torque of the motor, providing instantaneous strong reverse acceleration. Utilizing the rotational inertia of the fluid inside the cup relative to the cup wall, a centripetal water hammer impact force is generated, forcibly squeezing the air bubble in the center of the blade. The attenuation coefficient is set to 10 to 20 to control the rate at which the braking force disappears and prevent the motor from rotating in the opposite direction after the fluid has come to a standstill. The oscillation frequency is set to 10Hz to 30Hz, and a cosine term is introduced. The braking torque fluctuates periodically in direction or magnitude over a short period of time. This high-frequency mechanical vibration helps to break the surface tension between the food and the cup wall, causing the thick food clinging to the wall to slide down to the blade area.

[0094] The specific timing of this exception handling process is as follows: time Detected The control module triggers a braking interruption.

[0095] time Apply the formula described above. At this point, the user will observe that the ingredients inside the mixing cup 101 undergo a violent centripetal collapse, and the vacuum cavity is broken.

[0096] time : Stop the motor and let it stand still, waiting for the food to flow back and completely cover the blade.

[0097] time The control module re-executes a soft start, but automatically limits the target speed to a low gear to prevent air intake from recurring.

[0098] In existing technologies, when a mixer runs dry, users typically need to manually stop it and use the stirring rod to assist in pressing it down, which is cumbersome and poses safety hazards. This embodiment achieves millisecond-level cavitation detection by monitoring the abrupt change in the derivative of fluid resistance; and automatically eliminates cavitation using fluid dynamics principles through generated oscillation braking. This not only protects the motor from high-speed no-load overheating but also achieves fully automated, unattended mixing, significantly improving the user experience.

[0099] Example 3 Please refer to Figure 3The diagram illustrates a structural schematic of a computer device provided by some embodiments of this application. The computer device 20 includes: a control module 200, a memory 201, a bus 202, and a communication interface 203. The control module 200, the communication interface 203, and the memory 201 are connected via the bus 202. The memory 201 stores a computer program that can run on the control module 200. The control module 200 is used to operate according to the instructions to execute the steps described in Embodiment 2.

[0100] The memory 201 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface 203 (which can be wired or wireless), such as the Internet, wide area network, local area network, or metropolitan area network.

[0101] Bus 202 can be an ISA bus, PCI bus, or EISA bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. The memory 201 is used to store programs. After receiving an execution instruction, the control module 200 executes the program. The core lamination process disclosed in any of the foregoing embodiments of this application can be applied to the control module 200, or implemented by the control module 200.

[0102] The control module 200 may be an integrated circuit chip with signal processing capabilities. In implementation, the above steps can be completed through integrated logic circuits in the hardware or software instructions within the control module 200. The control module 200 can be a general-purpose control module, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processing Unit (DSP), an Application-Specific Integrated Circuit (ASIC), an Off-the-shelf Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or it can implement or execute the steps and logic block diagrams disclosed in the embodiments of this application. The general-purpose control module can be a microcontroller module or any conventional control module. The steps disclosed in the embodiments of this application can be directly manifested as execution by a hardware decoding control module, or execution by a combination of hardware and software modules within the decoding control module. The software module can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 201. The control module 200 reads the information in memory 201 and completes the above steps in conjunction with its hardware.

[0103] Example 4 This embodiment also provides a computer-readable storage medium corresponding to the core lamination process provided in the foregoing embodiments. Please refer to [link / reference]. Figure 4 The computer-readable storage medium shown is an optical disc, on which a computer program (i.e., program product 30) is stored. When the controlled module is running, the computer program executes the core lamination process provided in any of the aforementioned embodiments.

[0104] It should be noted that examples of the computer-readable storage medium may also include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical and magnetic storage media, which will not be elaborated here.

[0105] The computer-readable storage medium provided in the above embodiments of this application and the core lamination process provided in the embodiments of this application are based on the same application concept and have the same beneficial effects as the methods adopted, run or implemented by the application programs stored therein.

[0106] It should be noted that in the above text, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0107] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A mixer with good mixing effect, characterized in that, The device includes a mixing cup, a drive motor, a control module, and a blade assembly mounted on the output shaft of the drive motor. The blade assembly includes a first blade and a second blade stacked together. The first blade has an upwardly bent stirring blade, and the second blade has a horizontal pulverizing blade with serrated cutting edges. The control module includes a current sampling unit, a calculation unit, and a frequency conversion drive unit. The control module is used to establish a mapping relationship between the specific physical shape of the blade and the current waveform characteristics of the motor according to the operating state of the drive motor, and to adjust the output commands to the drive motor in real time.

2. The mixer with good mixing effect according to claim 2, characterized in that, The control module is used to perform the following steps: S100. The variable frequency drive unit controls the drive motor to operate at a preset initial speed. During operation, the real-time motor phase current signal sequence is acquired through the current sampling unit. ; S200. The arithmetic unit processes the current signal sequence. Time-domain and frequency-domain analyses were performed to calculate the impact characteristic index characterizing the hardness of the food. And fluid resistance, which characterizes the viscosity of food ingredients. ; S300. The computing unit will impact the characteristic index. and fluid resistance index Substituting the preset multidimensional coupling control function, the optimal target rotation speed under the current food condition is calculated. ; S400. Variable frequency drive unit based on optimal target speed. generate The control signal adjusts the motor speed until... Once the decay rate drops below the preset threshold, the grinding process begins.

3. The mixer with good mixing effect according to claim 2, characterized in that, In step S200, the impact characteristic index is calculated using the instantaneous high-frequency pulse current characteristics generated by the serrated cutting edge of the second blade when it impacts hard food. ; The length of the operation unit is Current sampling points within the time window The kurtosis of the current signal is calculated using a fourth-order central moment algorithm, and this is used as the impact characteristic index. The calculation formula is as follows: in, For the first The instantaneous current value at each sampling point The current is the average value within this time window, and constant 3 is the kurtosis reference value for the normal distribution.

4. A mixer with good mixing effect according to claim 2, characterized in that, In step S200, the fluid resistance index is calculated using the nonlinear relationship between the axial pumping resistance generated by the upward-moving stirring blades rotating in the fluid and the fluid viscosity. ; The computational unit constructs an observer model based on the extended Kalman filter to calculate the fluid drag exponent. The state estimation algorithm is as follows: in, For the first Estimated load torque at time, The moment of inertia of the motor and tool system. The coefficient of mechanical friction, The current mechanical angular velocity, For the first The fluid resistance index at time t. The shape factor is related to the hydrodynamic characteristics of the upward stirring blades, and its value ranges from 1.8 to 2.

2.

5. A mixer with good mixing effect according to claim 2, characterized in that, In step S300, the optimal target rotational speed is calculated. The specific process is as follows: Based on the impact characteristic index calculated in real time The speed is dynamically adjusted, and the calculation formula is as follows: in, The set maximum cell-wall breaking speed, To maintain the lowest possible speed for the minimum cycle, To adjust the sensitivity coefficient, The kurtosis threshold is used to characterize the critical point of food breakage.

6. A mixer with good mixing effect according to claim 2, characterized in that, The steps performed by the control module further include step S500: when the fluid resistance index The first derivative is less than the preset negative threshold At that time, it was determined that a vacuum cavity was formed around the blade; At this time, the drive motor is controlled to perform pulse braking, and the braking torque... The following formula is used for calculation: in, This is the maximum braking torque of the drive motor. The attenuation coefficient is... This represents the oscillation frequency.

7. An electronic device, characterized in that, It includes a memory, a control module, and a computer program stored in the memory and executable on the control module, the control module running the computer program to perform the steps as described in any one of claims 2-6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the control module to implement the steps as described in any one of claims 2-6.

Images