Silent kneader

Abstract

This invention relates to the field of dough kneading machine technology, and more particularly to a silent dough kneading machine. The silent dough kneading machine achieves silent kneading through the following steps: Step A, maintaining the system's suspended state; Step B, magnetic field-oriented control drive; Step C, dynamic load sensing; Step D, torque feedforward compensation. This invention achieves flexible floating of the modular powertrain through a three-dimensional suspended support component, utilizes a magnetic field-oriented control vector drive algorithm to drive a brushless DC motor, and combines dynamic load sensing and torque feedforward compensation. This achieves physical isolation of mechanical vibrations along the power transmission path and active torque offsetting of nonlinear load pulsations, significantly reducing operating noise and improving rotational stability.

Description

Technical Field

[0001] This invention relates to the field of dough kneading machine technology, and more particularly to a silent dough kneading machine. Background Technology

[0002] Traditional dough kneading machines typically use a series-wound motor or a traditional AC induction motor as their power source, which is rigidly connected to the mixing mechanism via pulleys or gear sets.

[0003] In existing technologies, the kneading process involves the continuous stretching, folding, and rebound of the dough, resulting in a highly nonlinear and pulsating load on the mixing mechanism. Because the motor drive algorithm responds slowly and cannot match these sudden load changes in real time, the motor rotor experiences frequent momentary stalls and vibrations, accompanied by loud mechanical collision noises.

[0004] In addition, existing powertrains are mostly fixed directly to the frame with fasteners such as bolts. The high-frequency vibrations and electromagnetic harmonics generated when the motor is running will be directly transmitted to the outer casing through rigid connectors, resulting in large-area sound radiation. This leads to high noise levels in the whole machine, which seriously affects the user experience and the acoustic quality of the product.

[0005] Therefore, the industry urgently needs a silent dough kneading machine that can solve the technical problems of excessive mechanical resonance noise and speed fluctuation impact noise caused by the rigid coupling of the power transmission path and the lag in the response of motor control to dynamic loads in existing dough kneading machines. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a silent dough kneading machine. This machine achieves flexible floating of the modular powertrain through a three-dimensional suspension support component, utilizes a magnetic field-oriented control vector drive algorithm to drive a brushless DC motor, and combines dynamic load sensing and torque feedforward compensation. This achieves physical isolation of mechanical vibrations along the power transmission path and active torque offsetting of nonlinear load pulsations, significantly reducing operating noise and improving rotational stability.

[0007] To achieve the above objectives, the present invention provides a silent dough kneading machine, which achieves silent dough kneading through the following steps:

[0008] Step A: The system maintains its suspended state by using a three-dimensional suspension support assembly to float and support the modular powertrain on the main body of the casing. The composite damping characteristics of the three-dimensional suspension support assembly are used to isolate the transmission of mechanical vibrations during the operation of the modular powertrain. Step B, field-oriented control drive, uses the integrated control module to execute the field-oriented control vector drive algorithm to drive the brushless DC motor in the modular powertrain. Step C, dynamic load sensing, involves sensing the abrupt changes in the stirring load at the millisecond level by real-time monitoring of the electromagnetic parameters of the brushless DC motor. Step D, torque feedforward compensation, calculates and injects compensation torque in real time based on the perceived abrupt change characteristics to counteract the effect of load pulsation on rotational stability.

[0009] Preferably, the magnetic field orientation control vector drive algorithm in step B specifically includes the following sub-steps: The coordinate transformation step utilizes the rotor position angle and uses Clark transformation and Park transformation to convert the three-phase stator current of the brushless DC motor into the measured values ​​of the d-axis current and q-axis current in the synchronous rotating coordinate system. The decoupling control step involves independently performing proportional-integral control on the measured values ​​of the d-axis current and the q-axis current, with the reference value of the d-axis current set to zero, and outputting the command values ​​of the d-axis voltage and the command values ​​of the q-axis voltage. The inverse transformation step utilizes the rotor position angle and uses inverse Park transformation to convert the d-axis voltage command value and q-axis voltage command value into a voltage vector in the stationary coordinate system, and uses space vector pulse width modulation technology to generate the switching signal to drive the inverter.

[0010] Preferably, the magnetic field orientation control vector drive algorithm further includes an angle observation step: The rotor flux linkage position is estimated in real time based on the terminal voltage and phase current of the brushless DC motor using a sliding mode observer or a Luneburg observer, and the estimated rotor flux linkage position is used as the rotor position angle and input into the coordinate transformation step and the inverse transformation step.

[0011] Preferably, the dynamic load sensing in step C specifically includes: The measured value of the q-axis current of the brushless DC motor was sampled at a frequency of not less than 10 kHz. The measured value of the q-axis current is input into the preset load observer model. The load observer model calculates the estimated load torque value based on the electromagnetic torque constant and rotational inertia parameters of the brushless DC motor. By comparing the rate of change of the estimated load torque within a continuous sampling period, when the rate of change exceeds a preset change threshold, it is identified as a load mutation component caused by the dough impacting the mixing drum.

[0012] Preferably, the torque feedforward compensation in step D specifically includes: The calculated current compensation value is positively correlated with the load abrupt change component; The current compensation value is superimposed on the output of the speed loop proportional-integral-derivative control algorithm to generate the q-axis current reference value for the current loop control algorithm. The output torque of the brushless DC motor is adjusted by setting a reference value for the q-axis current, so that the brushless DC motor can maintain a constant speed during sudden load changes.

[0013] Preferably, it also includes a viscoelastic property identification step, which specifically includes the following sub-steps: The feature sampling step records the maximum value of the q-axis current, the minimum value of the q-axis current, and the slope of the rising segment of the q-axis current in real time within a preset cycle during which the brushless DC motor drives the stirring hook to rotate. In the state mapping step, the difference between the maximum and minimum values ​​of the q-axis current is calculated and defined as the torque fluctuation ratio. If the torque fluctuation ratio increases regularly over time and the slope of the rising segment of the q-axis current exceeds a preset slope threshold, the dough is determined to have entered the high elasticity stage. If the maximum value of the q-axis current continues to exceed a preset high torque threshold and the torque fluctuation ratio shows a decreasing trend, the dough is determined to have entered the high viscosity heavy load stage. The parameter dynamic matching step adjusts the control parameters of the speed loop proportional-integral-derivative (PID) control algorithm in real time according to the determined dough state. Specifically, when the dough is determined to be in a high elasticity stage, the proportional coefficient in the speed loop PLD control algorithm is decreased; when the dough is determined to be in a high viscosity heavy load stage, the proportional coefficient in the speed loop PLD control algorithm is increased.

[0014] Preferably, the parameter dynamic matching step specifically includes: When the high elasticity stage is determined, the integrated control module reduces the proportional coefficient in the speed loop proportional-integral-derivative control algorithm to the preset elasticity compensation value, so as to reduce the response sensitivity of the brushless DC motor to the instantaneous torque change caused by the rebound of the dough, thereby eliminating torque pulsation resonance. When the high-viscosity heavy-load stage is determined, the integrated control module increases the proportional coefficient in the speed loop proportional-integral-derivative control algorithm and decreases the integral coefficient in the speed loop proportional-integral-derivative control algorithm to enhance the rigid torque output capability of the brushless DC motor, eliminate speed fluctuations caused by integral saturation, and maintain the smooth operation of the brushless DC motor under heavy load.

[0015] Preferably, the silent dough kneading machine also includes an envelope analysis step for viscoelasticity identification, which specifically includes the following sub-steps: The viscosity reference determination sub-step calculates the integral average value of the q-axis current over multiple consecutive rotation cycles; compares the integral average value with a preset no-load torque current reference, and determines the viscosity reference of the dough based on the difference between the integral average value and the preset no-load torque current reference. The gluten development status determination sub-step collects the rotor mechanical angle at the moment when the q-axis current waveform reaches its maximum peak within a single cycle, and defines the rotor mechanical angle as the peak phase angle; monitors the change trend of the peak phase angle with kneading time, and if the peak phase angle shifts towards the angle direction of the mixing hook cutting into the dough and the shift exceeds the preset angle threshold, it is determined that the gluten development of the dough has reached the preset mature state.

[0016] Preferably, it also includes an adaptive resonant frequency avoidance step, which specifically includes: The spectrum acquisition sub-step involves using vibration sensors installed on the modular powertrain to collect the mechanical vibration frequencies of the modular powertrain and extracting the characteristic frequencies corresponding to the maximum vibration amplitude. The resonance determination sub-step calculates the frequency deviation between the characteristic frequency and the preset stored table of inherent resonant frequencies of the chassis. The active avoidance sub-step involves performing frequency avoidance actions if the frequency deviation value is less than the preset safe frequency threshold.

[0017] Preferably, the three-dimensional suspension support assembly includes at least four sets of composite damping shock absorber bearings, and the at least four sets of composite damping shock absorber bearings are arranged asymmetrically with the center of gravity of the modular powertrain as the center. The composite damping shock absorber includes an inner soft core and an outer elastic sleeve nested outside the inner soft core. The inner soft core is made of silicone material with a Shore A hardness of 30 to 45 degrees. The cross-section of the outer elastic sleeve has a gradually changing structure along the axial direction, so that the composite damping shock absorber can generate nonlinear stiffness feedback during compression.

[0018] The beneficial effects of this invention are as follows: Flexible floating of the modular powertrain is achieved through a three-dimensional suspension support component; a brushless DC motor is driven using a magnetic field-oriented control vector drive algorithm; and dynamic load sensing and torque feedforward compensation are combined. This achieves physical isolation of mechanical vibrations along the power transmission path and active torque offsetting of nonlinear load pulsations, significantly reducing operating noise and improving rotational stability. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the steps involved in achieving silent dough kneading in this invention.

[0020] Figure 2 This is a schematic diagram of the structure of the present invention.

[0021] The reference numerals in the figures include: 1. Three-dimensional suspension support assembly; 2. Modular powertrain; 21. Brushless DC motor; 3. Main body of the casing; 31. Support frame. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings.

[0023] like Figures 1 to 2 As shown, the present invention provides a silent dough kneading machine, which achieves silent dough kneading through the following steps: Step A: The system maintains its suspended state. The modular powertrain 2 is floated and supported on the support frame 31 of the main body 3 of the casing using the three-dimensional suspension support component 1. The composite damping characteristics of the three-dimensional suspension support component 1 isolate the transmission of mechanical vibrations from the modular powertrain 2 during operation. The three-dimensional suspension support component 1 constructs a flexible interface between the power source and the main body 3 of the casing through physical displacement compensation and composite damping characteristics. The three-dimensional suspension support component 1 absorbs the multi-directional mechanical impacts generated by the modular powertrain 2 using multi-dimensional degrees of freedom. This completely isolates the transmission path of vibrations from the modular powertrain 2 to the support frame 31 during operation, solving the problem of large-area sound radiation from the main body 3 of the casing caused by rigid fastener connections.

[0024] Step B involves field-oriented control drive. The integrated control module executes a field-oriented control vector drive algorithm to drive the brushless DC motor 21 in the modular powertrain 2. The brushless DC motor 21 eliminates the brush structure, driving the rotor rotation through a sinusoidal current output from the integrated control module. This avoids the mechanical collision noise and high-frequency electromagnetic noise generated by carbon brush friction in traditional series motors, reducing the original sound level from the power source.

[0025] Step C, dynamic load sensing, involves real-time monitoring of the electromagnetic parameters of the brushless DC motor 21 to detect the millisecond-level abrupt changes in the stirring load. The magnetic field-oriented control vector drive algorithm decouples the stator current into the q-axis current that generates torque and the d-axis current that generates the magnetic field, achieving precise phase positioning of the stator magnetic field. This ensures the roundness of the motor's air gap magnetic field, eliminates torque pulsation harmonics under traditional drive methods, and suppresses electromagnetic harmonic noise from the motor in the background technology.

[0026] Step D, torque feedforward compensation, calculates and injects compensation torque in real time based on the perceived abrupt change characteristics to counteract the effect of load pulsation on rotational stability.

[0027] By sampling electromagnetic parameters in real time at the millisecond level and calculating load abrupt changes, a compensating torque is injected into the feedforward loop to offset the resistance. This overcomes the load impact caused by the "nonlinear pulsating characteristics" during dough kneading, and eliminates instantaneous stall and vibration of the motor rotor through active torque counterbalancing, thus maintaining rotational stability.

[0028] During the operation of the silent dough mixer, the integrated control module drives the brushless DC motor 21 to move the mixing hook into the dough, while the three-dimensional suspension support component 1 maintains the modular powertrain 2 in a stable suspended state. When the mixing hook impacts the hard dough, causing a millisecond-level load change, the dynamic load sensor captures the fluctuation of the current parameters, and the torque feedforward compensation instantly injects reverse torque to counteract the load pulsation. When the machine handles stretching and folding actions, the powertrain only floats slightly within the three-dimensional suspension support component 1 without touching the main body 3 of the machine casing, achieving a smooth and silent operation throughout the entire process from feeding and mixing to gluten development.

[0029] The magnetic field orientation control vector drive algorithm in step B of this embodiment specifically includes the following sub-steps: The coordinate transformation step utilizes the rotor position angle and uses Clark transformation and Park transformation to convert the three-phase stator current of the brushless DC motor 21 into the measured values ​​of the d-axis current and q-axis current in the synchronous rotating coordinate system. The decoupling control step involves independently performing proportional-integral control on the measured values ​​of the d-axis current and the q-axis current, with the reference value of the d-axis current set to zero, and outputting the command values ​​of the d-axis voltage and the command values ​​of the q-axis voltage. The inverse transformation step utilizes the rotor position angle and uses inverse Park transformation to convert the d-axis voltage command value and q-axis voltage command value into a voltage vector in the stationary coordinate system, and uses space vector pulse width modulation technology to generate the switching signal to drive the inverter.

[0030] By transferring the control loop to a synchronous rotating coordinate system through the Clarke / Parker transformation and setting the d-axis current reference value to zero, maximum torque-to-current ratio control is achieved, which reduces energy consumption and completely eliminates speed fluctuations caused by current component coupling.

[0031] The magnetic field orientation control vector drive algorithm in this embodiment also includes an angle observation step: The rotor flux position is estimated in real time based on the terminal voltage and phase current of the brushless DC motor 21 using a sliding mode observer or a Luneburg observer, and the estimated rotor flux position is used as the rotor position angle and input into the coordinate transformation step and the inverse transformation step.

[0032] Rotor flux linkage position is estimated imperceptibly from electrical signals using a sliding mode / Lumberjack observer, replacing physical sensors. This avoids feedback errors caused by high temperatures and vibrations affecting physical position sensors, improving the closed-loop accuracy of vector control under extreme conditions.

[0033] The dynamic load sensing in step C of this embodiment specifically includes: The measured value of the q-axis current of the brushless DC motor 21 was sampled at a frequency of not less than 10 kHz. The measured value of the q-axis current is input into the preset load observer model. The load observer model calculates the estimated load torque value based on the electromagnetic torque constant and rotational inertia parameters of the brushless DC motor 21. By comparing the rate of change of the estimated load torque within a continuous sampling period, when the rate of change exceeds a preset change threshold, it is identified as a load mutation component caused by the dough impacting the mixing drum.

[0034] High-frequency sampling of at least 10 kHz, combined with a load observer model, is used to identify the abrupt changes caused by dough impact. This significantly reduces the delay time from load change to system perception, ensuring that the compensation torque takes effect immediately upon impact.

[0035] The torque feedforward compensation in step D of this embodiment specifically includes: The calculated current compensation value is positively correlated with the load abrupt change component; The current compensation value is superimposed on the output of the speed loop proportional-integral-derivative control algorithm to generate the q-axis current reference value for the current loop control algorithm. The output torque of the brushless DC motor 21 is adjusted by setting the reference value of the q-axis current, so that the brushless DC motor 21 maintains a constant speed during sudden load changes.

[0036] The compensation value is directly superimposed on the speed loop PI output and used as the q-axis reference value for the current loop. This shortens the regulation path, allowing the motor output torque to "predict" and counteract the dough resistance, thus eliminating the frequent instantaneous stall mentioned in the background technology.

[0037] This embodiment also includes a viscoelastic property identification step, which specifically includes the following sub-steps: The feature sampling step records the maximum value of the q-axis current, the minimum value of the q-axis current, and the slope of the rising segment of the q-axis current in real time within a preset cycle during which the brushless DC motor 21 drives the stirring hook to rotate. In the state mapping step, the difference between the maximum and minimum values ​​of the q-axis current is calculated and defined as the torque fluctuation ratio. If the torque fluctuation ratio increases regularly over time and the slope of the rising segment of the q-axis current exceeds a preset slope threshold, the dough is determined to have entered the high elasticity stage. If the maximum value of the q-axis current continues to exceed a preset high torque threshold and the torque fluctuation ratio shows a decreasing trend, the dough is determined to have entered the high viscosity heavy load stage. The parameter dynamic matching step adjusts the control parameters of the speed loop proportional-integral-derivative (PID) control algorithm in real time according to the determined dough state. Specifically, when the dough is determined to be in a high elasticity stage, the proportional coefficient in the speed loop PLD control algorithm is decreased; when the dough is determined to be in a high viscosity heavy load stage, the proportional coefficient in the speed loop PLD control algorithm is increased.

[0038] The dough's state ("high elasticity stage" or "high viscosity heavy load stage") is determined by parameters such as the peak value and slope of the q-axis current. This achieves dynamic adaptation between control parameters and dough state, solving the technical pain point that a single parameter cannot be compatible with the entire kneading cycle.

[0039] The parameter dynamic matching steps in this embodiment specifically include: When the high elasticity stage is determined, the integrated control module reduces the proportional coefficient in the speed loop proportional integral derivative control algorithm to the preset elasticity compensation value, so as to reduce the response sensitivity of the brushless DC motor 21 to the instantaneous torque change caused by the rebound of the dough, thereby eliminating torque pulsation resonance. When the high-viscosity heavy load stage is determined, the integrated control module increases the proportional coefficient in the speed loop proportional-integral-derivative control algorithm and decreases the integral coefficient in the speed loop proportional-integral-derivative control algorithm to enhance the rigid torque output capability of the brushless DC motor 21 and eliminate speed fluctuations caused by integral saturation, thereby maintaining the smooth operation of the brushless DC motor 21 under heavy load.

[0040] In the high-elasticity stage, the proportional coefficient is reduced, while in the high-viscosity stage, the proportional coefficient is increased and the integral coefficient is reduced. This effectively suppresses control overshoot caused by dough rebound and eliminates integral saturation under heavy load, further optimizing operational smoothness.

[0041] The silent dough mixer in this embodiment also includes an envelope analysis step for viscoelastic property identification. The envelope analysis step specifically includes the following sub-steps: The viscosity reference determination sub-step calculates the integral average value of the q-axis current over multiple consecutive rotation cycles; compares the integral average value with a preset no-load torque current reference, and determines the viscosity reference of the dough based on the difference between the integral average value and the preset no-load torque current reference. The gluten development status determination sub-step collects the rotor mechanical angle at the moment when the q-axis current waveform reaches its maximum peak within a single cycle, and defines the rotor mechanical angle as the peak phase angle; monitors the change trend of the peak phase angle with kneading time, and if the peak phase angle shifts towards the angle direction of the mixing hook cutting into the dough and the shift exceeds the preset angle threshold, it is determined that the gluten development of the dough has reached the preset mature state.

[0042] The system monitors the shift trend of the peak phase angle relative to the cutting angle of the mixing hook. This enables precise identification of the dough's gluten development stage, ensuring timely stopping of the machine when the optimal texture is achieved, and preventing over-kneading.

[0043] This embodiment also includes an adaptive resonant frequency avoidance step, which specifically includes: The spectrum acquisition sub-step involves using a vibration sensor installed on the modular powertrain 2 to collect the mechanical vibration frequency of the modular powertrain 2 and extracting the characteristic frequency corresponding to the maximum vibration amplitude. The resonance determination sub-step calculates the frequency deviation between the characteristic frequency and the preset stored table of inherent resonant frequencies of the chassis. The active avoidance sub-step involves performing frequency avoidance actions if the frequency deviation value is less than the preset safe frequency threshold.

[0044] The system compares the powertrain's vibration characteristic frequency with the engine casing's natural frequency in real time and performs frequency avoidance actions (adjusting the PWM frequency or fine-tuning the engine speed). This proactively avoids the system's mechanical resonance points and solves the problem of large-area acoustic radiation resonance in the engine casing at the algorithm level.

[0045] Specifically, the frequency avoidance action performed in the active avoidance sub-step includes: fine-tuning the pulse width modulation carrier frequency, and / or adjusting the given speed of the brushless DC motor 21 by 1% to 3% to achieve the frequency avoidance action.

[0046] The three-dimensional suspension support assembly 1 in this embodiment includes at least four sets of composite damping shock absorbers, which are asymmetrically arranged around the center of gravity of the modular powertrain 2. This asymmetrical arrangement further utilizes the principle of spatial moment balance by setting at least four sets of composite damping shock absorbers in an asymmetrical configuration. This further achieves precise compensation for the eccentric moment of the modular powertrain 2, solving the swaying instability problem that still exists under non-uniform surface loads in symmetrical arrangements.

[0047] The composite damping shock absorber includes an inner soft core and an outer elastic sleeve nested outside the inner soft core. The inner soft core is made of silicone material with a Shore A hardness of 30 to 45 degrees. The cross-section of the outer elastic sleeve has a gradually changing structure along the axial direction, so that the composite damping shock absorber can generate nonlinear stiffness feedback during compression.

[0048] By using silicone material with a Shore A hardness of 30 to 45 degrees as the inner soft core, the viscoelastic damping properties of polymer materials are utilized. This further achieves deep absorption of high-frequency micro-vibrations and solves the problem of insufficient effectiveness of the basic scheme in eliminating micro-amplitude solid-borne sounds such as electromagnetic howling.

[0049] The inner soft core utilizes the ultra-low elastic modulus of 30° silicone, which can generate elastic deformation under minute vibration energy, thereby maximizing the absorption of minute vibrations caused by electromagnetic harmonics and eliminating high-frequency electromagnetic howling.

[0050] The inner soft core uses 38° silicone to balance the damping ratio and support stiffness, effectively filtering mid-frequency mechanical noise and maintaining the dynamic quasi-balance state of the system while ensuring that the modular powertrain 2 does not produce large displacement.

[0051] The inner soft core uses the hardness of 45° silicone to provide necessary physical support, preventing the modular powertrain 2 from touching the support frame 31 under heavy impact, thus solving the problem of instantaneous collision noise caused by rigid contact.

[0052] By designing the outer elastic sleeve as a gradually changing structure, the nonlinear stiffness feedback principle generated by variable cross-section compression is utilized. This further enables adaptive stiffness adjustment and solves the problem of structural bottoming noise easily generated by the damping components under extreme heavy load conditions such as strong impacts from dough in foundation schemes.

[0053] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A silent dough kneading machine, characterized in that, A silent dough kneading machine achieves silent dough kneading through the following steps: Step A: The system is kept in a suspended state. The modular powertrain (2) is floated and supported on the support frame (31) of the main body (3) by the three-dimensional suspension support component (1). The composite damping characteristics of the three-dimensional suspension support component (1) are used to isolate the mechanical vibration transmission of the modular powertrain (2) during operation. Step B, magnetic field orientation control drive, using the integrated control module to execute the magnetic field orientation control vector drive algorithm to drive the brushless DC motor (21) in the modular powertrain (2) to run; Step C, dynamic load sensing, by real-time monitoring of the electromagnetic parameters of the brushless DC motor (21), the abrupt change characteristics of the stirring load at the millisecond level are sensed; Step D, torque feedforward compensation, calculates and injects compensation torque in real time based on the perceived abrupt change characteristics to counteract the effect of load pulsation on rotational stability.

2. The silent dough kneading machine according to claim 1, characterized in that, The magnetic field orientation control vector drive algorithm in step B specifically includes the following sub-steps: The coordinate transformation step utilizes the rotor position angle and uses Clark transformation and Park transformation to convert the three-phase stator current of the brushless DC motor (21) into the measured values ​​of the d-axis current and q-axis current in the synchronous rotating coordinate system. The decoupling control step involves independently performing proportional-integral control on the measured values ​​of the d-axis current and the q-axis current, with the reference value of the d-axis current set to zero, and outputting the command values ​​of the d-axis voltage and the command values ​​of the q-axis voltage. The inverse transformation step utilizes the rotor position angle and uses inverse Park transformation to convert the d-axis voltage command value and q-axis voltage command value into a voltage vector in the stationary coordinate system, and uses space vector pulse width modulation technology to generate the switching signal to drive the inverter.

3. A silent dough kneading machine according to claim 2, characterized in that, The magnetic field orientation control vector drive algorithm also includes an angle observation step: The rotor flux position is estimated in real time based on the terminal voltage and phase current of the brushless DC motor (21) using a sliding mode observer or a Luneburg observer, and the estimated rotor flux position is used as the rotor position angle and input into the coordinate transformation step and the inverse transformation step.

4. A silent dough kneading machine according to claim 1 or 2, characterized in that, The dynamic load sensing in step C specifically includes: The measured value of the q-axis current of the brushless DC motor (21) was sampled at a frequency of not less than 10 kHz. The measured value of the q-axis current is input into the preset load observer model. The load observer model calculates the load torque estimate based on the electromagnetic torque constant and rotational inertia parameters of the brushless DC motor (21). By comparing the rate of change of the estimated load torque within a continuous sampling period, when the rate of change exceeds a preset change threshold, it is identified as a load mutation component caused by the dough impacting the mixing drum.

5. A silent dough kneading machine according to claim 4, characterized in that, The torque feedforward compensation in step D specifically includes: The calculated current compensation value is positively correlated with the load abrupt change component; The current compensation value is superimposed on the output of the speed loop proportional-integral-derivative control algorithm to generate the q-axis current reference value for the current loop control algorithm. The output torque of the brushless DC motor (21) is adjusted by giving a reference value to the q-axis current, so that the brushless DC motor (21) maintains a constant speed during sudden load changes.

6. A silent dough kneading machine according to claim 1, characterized in that, It also includes a viscoelastic property identification step, which specifically includes the following sub-steps: In the feature sampling step, within the preset cycle of the brushless DC motor (21) driving the stirring hook to rotate, the maximum value of the q-axis current, the minimum value of the q-axis current, and the slope of the rising segment of the q-axis current are recorded in real time. In the state mapping step, the difference between the maximum and minimum values ​​of the q-axis current is calculated and defined as the torque fluctuation ratio. If the torque fluctuation ratio increases regularly over time and the slope of the rising segment of the q-axis current exceeds a preset slope threshold, the dough is determined to have entered the high elasticity stage. If the maximum value of the q-axis current continues to exceed the preset high torque threshold and the torque fluctuation ratio shows a decreasing trend, then the dough is determined to have entered the high viscosity heavy load stage. The parameter dynamic matching step adjusts the control parameters of the speed loop proportional-integral-derivative (PID) control algorithm in real time according to the determined dough state. Specifically, when the dough is determined to be in a high elasticity stage, the proportional coefficient in the speed loop PLD control algorithm is decreased; when the dough is determined to be in a high viscosity heavy load stage, the proportional coefficient in the speed loop PLD control algorithm is increased.

7. A silent dough kneading machine according to claim 6, characterized in that, The parameter dynamic matching step specifically includes: When the high elasticity stage is determined, the integrated control module reduces the proportional coefficient in the speed loop proportional integral derivative control algorithm to the preset elasticity compensation value, so as to reduce the response sensitivity of the brushless DC motor (21) to the instantaneous torque change generated by the dough rebound, thereby eliminating torque pulsation resonance. When the high viscosity heavy load stage is determined, the integrated control module increases the proportional coefficient in the speed loop proportional integral derivative control algorithm and decreases the integral coefficient in the speed loop proportional integral derivative control algorithm to enhance the rigid torque output capability of the brushless DC motor (21) and eliminate the speed fluctuation caused by integral saturation, so as to maintain the smooth operation of the brushless DC motor (21) under heavy load.

8. A silent dough kneading machine according to claim 7, characterized in that, The silent dough kneading machine also includes an envelope analysis step for viscoelastic property identification, which specifically includes the following sub-steps: The viscosity reference determination sub-step calculates the integral average value of the q-axis current over multiple consecutive rotation cycles; compares the integral average value with a preset no-load torque current reference, and determines the viscosity reference of the dough based on the difference between the integral average value and the preset no-load torque current reference. The gluten development status determination sub-step collects the rotor mechanical angle at the moment when the q-axis current waveform reaches its maximum peak within a single cycle, and defines the rotor mechanical angle as the peak phase angle; monitors the change trend of the peak phase angle with kneading time, and if the peak phase angle shifts towards the angle direction of the mixing hook cutting into the dough and the shift exceeds the preset angle threshold, it is determined that the gluten development of the dough has reached the preset mature state.

9. A silent dough kneading machine according to claim 1, characterized in that, It also includes an adaptive resonant frequency avoidance step, which specifically includes: The spectrum acquisition sub-step involves using a vibration sensor installed on the modular powertrain (2) to collect the mechanical vibration frequency of the modular powertrain (2) and extract the characteristic frequency corresponding to the maximum vibration amplitude. The resonance determination sub-step calculates the frequency deviation between the characteristic frequency and the preset stored table of inherent resonant frequencies of the chassis. The active avoidance sub-step involves performing frequency avoidance actions if the frequency deviation value is less than the preset safe frequency threshold.

10. A silent dough kneading machine according to claim 1, characterized in that, The three-dimensional suspension support assembly (1) includes at least four sets of composite damping shock absorber supports, which are arranged asymmetrically around the center of gravity of the modular powertrain (2). The composite damping shock absorber includes an inner soft core and an outer elastic sleeve nested outside the inner soft core. The inner soft core is made of silicone material with a Shore A hardness of 30 to 45 degrees. The cross-section of the outer elastic sleeve has a gradually changing structure along the axial direction, so that the composite damping shock absorber can generate nonlinear stiffness feedback during compression.

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