Motor driving method of food processor and food processor

Abstract

The application discloses a motor driving method of a food processor and the food processor. The motor driving method of the food processor comprises the following steps: obtaining a target rotating speed. According to the target rotating speed, the motor is driven to reach the target rotating speed in stages, wherein the stages comprise a high-torque driving stage, a constant-torque driving stage and a flexible-torque driving stage, so that the food processor can be started smoothly, and the starting noise is reduced.

Description

Technical Field

[0001] This application relates to the field of food processor technology, and in particular to a motor drive method for a food processor and a food processor. Background Technology

[0002] A food processor can be a machine that functions as a juicer, soy milk maker, ice cream maker, food processor, grinder, etc. After the food processor is powered on, its ultra-high speed (over 25,000 rpm) can instantly break down the cell walls of fruits and vegetables, effectively extracting phytochemicals.

[0003] Most of the food processors currently on the market use high-power motors with a power of over 1 kilowatt. These motors generate a large impact when they go from static to running, causing the food processor to vibrate. At the same time, the excessive noise can affect human hearing. Summary of the Invention

[0004] The main technical problem this application addresses is to provide a motor drive method for a food processor and a food processor in general, which can smoothly start the food processor and reduce startup noise.

[0005] One technical solution adopted in this application is a motor driving method for a food processor, comprising: obtaining a target rotational speed; and driving the motor to reach the target rotational speed in stages according to the target rotational speed, wherein the stages include a high-torque driving stage, a constant-torque driving stage, and a flexible-torque driving stage.

[0006] Furthermore, the motor is driven to reach the target speed in stages according to the target speed, including: in the high torque drive stage, the motor is driven to gradually increase its acceleration from 0 to a first acceleration, thereby gradually increasing its speed from 0 to a first speed. In the constant torque drive stage, the motor is driven to gradually increase its speed to a second speed with constant torque at the first acceleration. In the flexible torque drive stage, the motor is driven to gradually decrease its acceleration from the first acceleration to 0 while its speed reaches the target speed.

[0007] Furthermore, it also includes: detecting the current speed of the motor. Based on the current speed, the first speed, the second speed, and the target speed, the motor acceleration is adaptively adjusted for torque compensation.

[0008] Furthermore, detecting the current speed of the motor includes: during the high-torque drive phase, detecting the current speed of the motor using a high-frequency current injection method.

[0009] Furthermore, a first acceleration, a first rotational speed, and a second rotational speed are determined based on the target rotational speed, wherein the first acceleration is the optimal acceleration that matches the target rotational speed.

[0010] Furthermore, the first speed is in the range of 30 to 300 rpm, and the second speed is in the range of 300 to 3500 rpm.

[0011] Furthermore, it also includes: a preset time period for the drive motor to operate at the target speed.

[0012] Furthermore, it also includes: gradually reducing the drive motor from the target speed to a complete stop.

[0013] Further, the process of gradually reducing the motor speed from the target speed to a stop includes: driving the motor to gradually increase the motor acceleration from 0 to a reverse second acceleration, thereby gradually reducing the motor speed from the target speed to a third speed; driving the motor to gradually reduce the motor speed to a fourth speed with a reverse second acceleration; and driving the motor to gradually reduce the motor acceleration from the reverse second acceleration to 0 and gradually reduce the motor speed to a stop.

[0014] To solve the above-mentioned technical problems, another technical solution adopted in this application is: to provide a food processor, which includes a motor, a drive circuit and a control circuit, wherein the drive circuit is connected to the motor to drive the motor, and the control circuit is connected to the drive circuit to provide control signals to the drive circuit, thereby controlling the drive circuit to drive the motor to perform the above-mentioned motor drive method of the food processor.

[0015] The beneficial effects of this application are as follows: Unlike the prior art, this application first obtains the target speed, and then drives the motor to reach the target speed in stages according to the target speed. The stages include a high torque drive stage, a constant torque drive stage, and a flexible torque drive stage. In this way, the phenomenon of motor vibration, unstable start-up, and high noise caused by a single input when driving the motor is avoided. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of the food processor provided in this application;

[0018] Figure 2 yes Figure 1 A schematic diagram of the circuit structure of one embodiment of the control circuit;

[0019] Figure 3 yes Figure 1 A schematic diagram of the circuit structure of one embodiment of the driving circuit;

[0020] Figure 4 This is a flowchart illustrating the first embodiment of the motor driving method for the food processor provided in this application.

[0021] Figure 5 yes Figure 4 A flowchart illustrating an implementation method for step S202;

[0022] Figure 6 This is a flowchart illustrating the second embodiment of the motor driving method for the food processor provided in this application;

[0023] Figure 7 This is a schematic diagram of the curve coordinates of one implementation method of the motor operating speed curve. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0025] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0026] See Figure 1 , Figure 1 This is a schematic diagram of the structure of an embodiment of the food processor provided in this application, as shown below. Figure 1 As shown, the food processor 100 provided in this embodiment includes a motor 103, a drive circuit 102, and a control circuit 101. The food processor 100 can be a food processor with a wall-breaking function, or it can be a food processor with ordinary functions, such as a juicer, soy milk maker, ice cream maker, food processor, and grinder.

[0027] In this invention, drive circuit 102 is connected to motor 103 to drive motor 103, and control circuit 101 is connected to drive circuit 102 to provide control signals to drive circuit 102, thereby controlling drive circuit 102 to drive motor 103 to perform the steps of the motor 103 driving method of food processor 100 provided in this application. A detailed description of the motor 103 driving method of food processor 100 provided in this application will be provided below, and will not be elaborated upon here.

[0028] In a specific application scenario, refer to the following: Figures 1-3 , Figure 2 yes Figure 1 A schematic diagram of the circuit structure of one embodiment of the control circuit. Figure 3 yes Figure 1 A schematic diagram of the circuit structure of one embodiment of the drive circuit is shown in the figure. The control circuit 101 and the drive circuit 102 used to drive the motor 103 form a three-phase inverter drive circuit (not shown in the figure). The motor 103 is specifically a three-phase permanent magnet motor. The design of the three-phase inverter drive circuit uses the IR2316 from International Rectifier as the drive chip. This drive chip can have six power switching devices and is particularly suitable for speed regulation of drive motors.

[0029] The IR2136 driver chip charges the capacitors via a fast recovery diode and a power switch, ensuring that the upper and lower power switches on the same bridge arm cannot be turned on simultaneously. During system operation, excessive current is inevitable. In such cases, the IR2136 driver chip's protection circuit automatically detects and activates its internal protection based on the system's current operating state, thus protecting the entire control system. The drive circuit of power devices plays a crucial role in the speed control system of permanent magnet brushless DC motors.

[0030] Specifically, the functions of each pin of the driver chip IR2136 are as follows: HIN1~HIN3 and LIN1~LIN3 are the input ports of the upper and lower bridge arms, respectively; HO1~HO3 and LO1~LO3 are the inverted output terminals of the upper and lower bridge arms, respectively; ITRIP is the input terminal for overcurrent detection; VB1~VB3 and VS1~VS3 are the high-side floating power supply pin and the high-side floating bias voltage pin, respectively; FAULT indicates fault output and is active low.

[0031] The IR2136 driver chip changes the frequency of the three-phase PWM wave by controlling its duty cycle, thereby changing its speed and achieving vector control of the three-phase permanent magnet motor.

[0032] like Figure 2 and Figure 3 As shown, the VCC pin of the driver chip U4 is connected to the first end of capacitor C29, the second end of C29 is grounded, and the first end of capacitor C29 is also connected to a +15V power supply voltage.

[0033] The HIN1* pin of the driver chip U4 is connected to the first end of capacitor C30, the second end of capacitor C30 is grounded, the first end of capacitor C30 is also connected to the first end of resistor R50, and the second end of resistor R50 is connected to the pulse modulation signal terminal PWM_WH.

[0034] The HIN2* pin of the driver chip U4 is connected to the first end of capacitor C31, the second end of capacitor C31 is grounded, the first end of capacitor C31 is also connected to the first end of resistor R52, and the second end of resistor R52 is connected to the pulse modulation signal terminal PWM_VH.

[0035] The HIN3* pin of the driver chip U4 is connected to the first end of capacitor C32, the second end of capacitor C32 is grounded, the first end of capacitor C32 is also connected to the first end of resistor R53, and the second end of resistor R53 is connected to the pulse modulation signal terminal PWM_UH.

[0036] The LIN1* pin of the driver chip U4 is connected to the first end of capacitor C42, the second end of capacitor C42 is grounded, the first end of capacitor C42 is also connected to the first end of resistor R54, and the second end of resistor R54 is connected to the pulse modulation signal terminal PWM_WL.

[0037] The LIN2* pin of the driver chip U4 is connected to the first end of capacitor C43, the second end of capacitor C43 is grounded, the first end of capacitor C43 is also connected to the first end of resistor R55, and the second end of resistor R55 is connected to the pulse modulation signal terminal PWM_VL.

[0038] The LIN3* pin of the driver chip U4 is connected to the first end of capacitor C44, the second end of capacitor C44 is grounded, the first end of capacitor C44 is also connected to the first end of resistor R56, and the second end of resistor R56 is connected to the pulse modulation signal terminal PWM_UL.

[0039] The FAYLT* pin of the driver chip U4 is connected to the first terminal of capacitor C47, the second terminal of capacitor C47 is grounded, the first terminal of capacitor C47 is also connected to the first terminal of capacitor C46, ​​the second terminal of capacitor C46 is grounded, the first terminal of capacitor C47 is also connected to the first terminal of resistor R62, and the second terminal of resistor R62 is connected to a power supply voltage of 5V.

[0040] The ITRIP pin of the driver chip U4 is connected to the first end of resistor R65, the second end of resistor R65 is grounded, the first end of resistor R65 is also connected to the first end of capacitor C48, the second end of capacitor C48 is grounded, the first end of resistor R65 is also connected to the first end of resistor R66, the second end of resistor R66 is grounded, the first end of resistor R66 is connected to the first end of resistor R63, and the second end of resistor R63 is connected to the I_shunt1 pin.

[0041] The EN pin of the driver chip U4 is connected to the first end of resistor R58, and the second end of resistor R58 is connected to the EN pin.

[0042] The RCIN pin of the driver chip U4 is connected to the first terminal of capacitor C49, the second terminal of capacitor C49 is grounded, the first terminal of capacitor C49 is also connected to the first terminal of resistor R64, the second terminal of resistor R64 is connected to the first terminal of resistor R61, and the second terminal of resistor R61 is connected to a power supply voltage of +15V.

[0043] The VSS pin of the driver chip U4 is grounded.

[0044] The COM pin of the driver chip U4 is connected to the I_shunt1 terminal.

[0045] The LO1-LO3 pins of the driver chip U4 are connected to the LOW terminal, LOV terminal, and LOU terminal respectively (detailed below).

[0046] The VS3 pin of driver chip U4 is connected to the first terminal of capacitor C39. The second terminal of capacitor C39 is connected to the cathode of diode D12. The anode of diode D12 is connected to the first terminal of resistor R41. The second terminal of resistor R41 is connected to a +15V power supply. The first terminal of capacitor C39 is also connected to the first terminal of capacitor C40, and the second terminal of capacitor C39 is also connected to the second terminal of capacitor C40. The anode of diode D12 is also connected to the cathode of Zener diode ZD2, and the anode of Zener diode ZD2 is grounded. The first terminal of resistor R41 is also connected to the first terminal of resistor R44, and the second terminal of resistor R41 is also connected to the second terminal of resistor R44. The second terminal of resistor R41 is also connected to the first terminal of capacitor C24, which is grounded. The second terminal of resistor R41 is also connected to the first terminal of electrolytic capacitor EC5, which is grounded.

[0047] The HO1-HO3 pins of the driver chip U4 are connected to the HOW, HOV and HOU terminals respectively (detailed below).

[0048] The VB3 pin of the driver chip U4 is connected to the second end of capacitor C39.

[0049] The VS2 pin of the driver chip U4 is connected to the first terminal of capacitor C34, the second terminal of capacitor C34 is connected to the cathode of diode D11, and the anode of diode D11 is connected to the first terminal of resistor R41. The first terminal of capacitor C34 is also connected to the first terminal of capacitor C35, and the second terminal of capacitor C34 is also connected to the second terminal of capacitor C35.

[0050] The VB2 pin of the driver chip U4 is connected to the second end of capacitor C34.

[0051] The VS1 pin of the driver chip U4 is connected to the first terminal of capacitor C25. The second terminal of capacitor C25 is connected to the positive terminal of diode D11. The negative terminal of diode D11 is connected to the first terminal by resistor R41. The first terminal of capacitor C26 is connected to the first terminal of capacitor C25, and the second terminal of capacitor C26 is also connected to the second terminal of capacitor C25.

[0052] The VB1 pin of the driver chip U4 is connected to the second end of capacitor C26.

[0053] The HOU terminal is connected to the first terminal of resistor R75. The second terminal of resistor R75 is connected to the control stage G of IGBT1. The collector C of IGBT1 is connected to a power supply voltage of 310V. The emitter E of IGBT1 is connected to the first terminal of resistor R81. The second terminal of resistor R81 is connected to the second terminal of resistor R75. The first terminal of resistor R75 is also connected to the first terminal of resistor R78, and the second terminal of resistor R75 is also connected to the second terminal of resistor R78. The first terminal of resistor R81 is also connected to the first terminal of capacitor C70, and the second terminal of resistor R81 is also connected to the second terminal of capacitor C70. The emitter (E) of IGBT1 is connected to pin 3 of CN3 in the motor, and also to the collector (C) of IGBT4. The gate (G) of IGBT4 is connected to the first terminal of resistor R85. The second terminal of resistor R85 is connected to the LOU terminal. The first terminal of resistor R85 is connected to the first terminal of resistor R89. The second terminal of resistor R85 is connected to the second terminal of resistor R89. The first terminal of resistor R85 is also connected to the first terminal of resistor R93. The second terminal of resistor R93 is connected to the emitter (E) of IGBT4. The emitter (E) of IGBT4 is connected to the first terminal of resistor R96. The second terminal of resistor R96 is connected to the first terminal of resistor R74. The second terminal of resistor R74 is connected to the first terminal of capacitor C74. The second terminal of capacitor C74 is grounded.

[0054] The HOV terminal is connected to the first terminal of resistor R76. The second terminal of resistor R76 is connected to the control stage G of IGBT2. The collector C of IGBT2 is connected to a power supply voltage of 310V. The emitter E of IGBT2 is connected to the first terminal of resistor R82. The second terminal of resistor R82 is connected to the second terminal of resistor R76. The first terminal of resistor R76 is also connected to the first terminal of resistor R79, and the second terminal of resistor R76 is also connected to the second terminal of resistor R79. The first terminal of resistor R82 is also connected to the first terminal of capacitor C71, and the second terminal of resistor R82 is also connected to the second terminal of capacitor C71. The emitter (E) of IGBT2 is connected to pin 2 of CN3 in the motor, and also to the collector (C) of IGBT5. The gate (G) of IGBT5 is connected to the first terminal of resistor R86. The second terminal of resistor R86 is connected to the LOV terminal. The first terminal of resistor R86 is connected to the first terminal of resistor R90. The second terminal of resistor R86 is connected to the second terminal of resistor R90. The first terminal of resistor R86 is also connected to the first terminal of resistor R94. The second terminal of resistor R94 is connected to the emitter (E) of IGBT5. The emitter (E) of IGBT5 is connected to the first terminal of resistor R97. The second terminal of resistor R97 is connected to the second terminal of resistor R96.

[0055] The HOW terminal is connected to the first terminal of resistor R77. The second terminal of resistor R77 is connected to the control stage G of IGBT3. The collector C of IGBT3 is connected to a power supply voltage of 310V. The emitter E of IGBT3 is connected to the first terminal of resistor R83. The second terminal of resistor R83 is connected to the second terminal of resistor R77. The first terminal of resistor R77 is also connected to the first terminal of resistor R80, and the second terminal of resistor R77 is also connected to the second terminal of resistor R80. The first terminal of resistor R83 is also connected to the first terminal of capacitor C72, and the second terminal of resistor R83 is also connected to the second terminal of capacitor C72. The emitter (E) of IGBT3 is connected to pin 1 of CN3 in the motor, and also to the collector (C) of IGBT6. The gate (G) of IGBT6 is connected to the first terminal of resistor R87. The second terminal of resistor R87 is connected to the LOW terminal. The first terminal of resistor R87 is connected to the first terminal of resistor R91. The second terminal of resistor R87 is connected to the second terminal of resistor R91. The first terminal of resistor R87 is also connected to the first terminal of resistor R95. The second terminal of resistor R95 is connected to the emitter (E) of IGBT6. The emitter (E) of IGBT6 is connected to the first terminal of resistor R100. The second terminal of resistor R100 is grounded. The first terminal of resistor R100 is connected to the first terminal of resistor R99. The second terminal of resistor R99 is grounded. The first terminal of resistor R99 is also connected to the second terminal of resistor R97.

[0056] The power supply voltage of 310V is connected to the first terminal of capacitor C58, the second terminal of capacitor C58 is grounded, the first terminal of capacitor C58 is also connected to the first terminal of capacitor C57 and the first terminal of capacitor C56, and the second terminals of capacitor C57 and capacitor C56 are both grounded.

[0057] Optionally, IGBT1 through IGBT6 are insulated gate bipolar transistors.

[0058] The driver chip U4 is the IR2136 chip.

[0059] In summary, this embodiment uses the three-phase inverter drive circuit composed of the control circuit 101 and the drive circuit 102 to drive the motor 103, thereby realizing the motor drive method of the food processor provided in this application.

[0060] When starting up household appliances such as food processors, the motors are typically driven with a constant torque to achieve rapid acceleration. However, the inventors of this application have discovered through extensive research that driving the motor with a constant torque method easily leads to motor vibration, unstable starting, and excessive noise.

[0061] Based on this, the present application provides a motor driving method for a food processor. This motor driving method effectively avoids the problems of motor vibration, unstable start-up, and high noise caused by the constant torque drive motor in the prior art by dividing the motor driving stage into three stages: a high torque drive stage, a constant torque drive stage, and a flexible torque drive stage.

[0062] See Figure 4 , Figure 4 This is a flowchart illustrating the first embodiment of the motor driving method for the food processor provided in this application, as shown below. Figure 4 As shown, the motor driving method of the food processor includes the following steps:

[0063] S201: Obtain the target rotational speed.

[0064] The target rotational speed, also known as the target speed of rotation, refers to the desired rotational speed of the motor driving the food processor. Here, the target rotational speed can be an empirically set value. Specifically, it can be determined by setting the target speed level of the food processor, as each speed level corresponds to a different rotational speed. Therefore, once the target speed level is selected, the target rotational speed can be determined. Furthermore, the target rotational speed is generally low, for example, corresponding to speed one or two within the target speed level, where higher speed levels result in faster rotational speeds.

[0065] S202: Drive the motor in stages to reach the target speed according to the target speed.

[0066] The stages include a high-torque drive stage, a constant-torque drive stage, and a flexible-torque drive stage.

[0067] Optionally, during the high-torque drive phase, the drive motor gradually increases its acceleration from 0 to a first acceleration, thereby gradually increasing its rotational speed from 0 to a first rotational speed. That is, during the high-torque drive phase, the drive motor performs a variable acceleration motion with gradually increasing acceleration.

[0068] Optionally, during the constant torque drive phase, the drive motor gradually increases its speed to a second speed with a first acceleration and constant torque. That is, during the constant torque drive phase, the motor is driven with a constant acceleration.

[0069] During the flexible torque drive phase, the drive motor is driven to gradually reduce its acceleration from a first acceleration to zero while maintaining the target speed. Optionally, physical parameters such as back electromotive force can be used to estimate the rotor position, and then the motor speed during the constant torque drive phase can be calculated using the obtained rotor position.

[0070] Optionally, in this embodiment, a first acceleration, a first rotational speed, and a second rotational speed are determined based on the target rotational speed, wherein the first acceleration is the optimal acceleration matching the target rotational speed. Specifically, the first rotational speed, the second rotational speed, and the first acceleration are all values ​​related to the target rotational speed set to achieve smooth motor start-up.

[0071] For example, in a specific application scenario, the specific values ​​of the first acceleration, the first rotational speed, and the second rotational speed increase with the increase of the target rotational speed and decrease with the decrease of the target rotational speed. Optionally, the first rotational speed is located in the range of 30 to 300 rpm, and the second rotational speed is located in the range of 300 to 3500 rpm.

[0072] See Figure 5 , Figure 5 yes Figure 4 A flowchart illustrating an implementation method for step S202 is shown below. Figure 5 As shown, step S202 may include the following steps:

[0073] S2021: Detects the current speed of the motor.

[0074] In this embodiment, the current speed of the motor can include the speeds of the high torque drive stage, the constant torque drive stage, and the flexible torque drive stage, respectively.

[0075] Optionally, during the high-torque drive phase, the current speed of the motor is obtained using a high-frequency current injection method. High-frequency injection is a commonly used sensorless rotor position detection technology for permanent magnet synchronous motors during low-frequency startup. It features independence from motor back EMF, insensitivity to motor parameters, and strong robustness, making it particularly suitable for applications where the motor operates at low speeds. Since the motor speed increases from zero to its first speed during the high-torque drive phase—meaning the motor is operating at low speed during this phase—the high-torque drive phase uses a high-frequency current injection method to obtain the rotor position and thus the motor speed.

[0076] The principle of the high-frequency current injection method is as follows: a sinusoidal signal with an amplitude much lower than the DC bus voltage and a frequency much higher than the rotor electrical angle frequency is injected into the fundamental voltage of the motor. Then, the electronic current excited by the high-frequency signal is sampled, and a high-frequency signal containing the rotor position signal is obtained through a filter. Finally, the rotor position is calculated through a series of mathematical operations. In fact, when using pulsed high-frequency current injection for initial position estimation of permanent magnet synchronous motors, magnetic pole determination is required. A partitioned integration method is used, which evenly divides one injection signal cycle into four regions. The high-frequency voltage response of the d-axis is integrated in regions I and III. The positive direction of the d-axis is determined based on the sign of the integral value. This method eliminates the need for additional positive and negative pulse signals to determine the positive direction of the d-axis, shortens the estimation time, simplifies the estimation process, and avoids the rotor vibration problem that may occur when injecting positive and negative pulse voltages into small inertia motors.

[0077] In this embodiment, during the constant torque drive stage and the flexible torque drive stage, since the motor speed is relatively high, other methods can be used to obtain the current motor speed. For example, when the food processor motor is equipped with a position sensor, the position sensor is used to obtain the motor rotor position signal, and then the current motor speed is calculated based on the rotor position signal. Position sensors include, for example, Hall effect sensors, photoelectric encoders, etc., which are not specifically limited here. When the food processor motor is not equipped with a position sensor, a position detection method based on the motor's fundamental wave model can be used to obtain the motor rotor position signal. Specifically, this type of detection method typically uses voltage and current detection values ​​to obtain rotor position information based on the motor's dynamic data model (fundamental wave). The extracted position information mainly utilizes the relationship between back electromotive force and rotor position or speed, so it is often called a back electromotive force-based position detection method. Specifically, for example, the back electromotive force method, flux linkage method, assumed rotating coordinate system method, observer method, or model reference adaptive method can be used to obtain the motor rotor position signal.

[0078] S2022: Based on the current speed, the first speed, the second speed and the target speed, the motor acceleration is adaptively adjusted to perform torque compensation.

[0079] In this embodiment, the motor speed can be controlled in a closed loop using the PWM method. The control center (host) samples the motor speed parameter, calculates the speed value, and compares it with the predetermined speed setting value. If they are different, the duty cycle is adjusted to achieve the purpose of adjusting the motor speed.

[0080] Specifically, during the high-torque drive phase, the current motor speed is acquired in real time, and the difference between the first speed and the current speed is calculated. Based on this difference, the motor acceleration is adjusted from zero to the first acceleration. In a specific application scenario, the speed and acceleration curves can be set to be as continuous or smooth as possible to minimize motor vibration during operation and prevent pauses or abrupt changes, thereby improving positioning accuracy and work efficiency. For example, during the high-torque drive phase, the motor speed curve is V = t 3 Clearly, the acceleration curve of the motor is a = 3t. 2 In this case, the speed curve and acceleration curve are continuous and smooth, so the motor vibration during operation is small. In this embodiment, the curves of change of motor speed and acceleration can also be any other curves that meet the conditions, that is, the speed increases from 0 to the first speed and the acceleration increases from 0 to the first acceleration.

[0081] During the constant torque drive phase, the difference between the second speed and the current speed is calculated in real time. Based on the difference between the second speed and the current speed, while keeping the motor acceleration constant at the first acceleration, the motor speed is controlled to change from the first speed to the second speed.

[0082] During the flexible torque drive phase, the difference between the target speed and the current speed is calculated in real time. Based on this difference, the motor acceleration is controlled to change from a first acceleration to zero, and the motor speed increases from a second speed to the target speed. In this embodiment, the speed and acceleration curves can be set to be as continuous or smooth as possible to minimize motor vibration during movement and prevent pauses or abrupt changes, thereby improving positioning accuracy and work efficiency. For example, during the flexible torque drive phase, the motor speed curve is V = t 1 / 2 Clearly, the acceleration curve of the motor is a = 1 / 2t. (-1 / 2) In this case, the speed and acceleration curves are continuous and smooth, resulting in minimal vibration of the motor during operation. In this embodiment, the curves showing the changes in motor speed and acceleration can also be any other curves that satisfy the condition that the speed increases from the second speed to the target speed, and the acceleration decreases from the first acceleration to zero.

[0083] By using the above methods, the motor can smoothly reach the target speed after passing through the high torque drive stage, constant torque drive stage, and flexible torque drive stage, avoiding the adverse phenomena of high noise and high vibration.

[0084] Optionally, see Figure 6 , Figure 6 This is a flowchart illustrating the second embodiment of the motor driving method for the food processor provided in this application, as shown below. Figure 6 As shown, the motor driving method for the food processor provided in this embodiment includes the following steps:

[0085] S301: Obtain the target rotational speed.

[0086] S302: Drive the motor to reach the target speed in stages according to the target speed. The stages include a high torque drive stage, a constant torque drive stage, and a flexible torque drive stage.

[0087] S303: The drive motor operates at the target speed for a preset time period.

[0088] In this embodiment, steps S301 and S302 are the same as steps S201 and S202 of the first embodiment of the motor driving method for the food processor provided in this application. For details, please refer to steps S201 and S202, which will not be described in detail here.

[0089] In this example, the preset time period can be a manually set experience value. Alternatively, the preset time period can be the working duration of the target setting on the food processor. Since different settings on each food processor correspond to different menu functions, and different menu functions correspond to different working durations, the preset time period can be determined after selecting the target setting.

[0090] In this example, the drive motor operates at the target speed for a preset time period, thereby enabling the food processor to perform the corresponding menu functions.

[0091] Optionally, after the drive motor operates at the target speed for a preset time period, or after the drive motor reaches the target speed in stages, the drive motor gradually decreases from the target speed to stop.

[0092] Specifically, the motor is driven to gradually increase its acceleration from 0 to a second reverse acceleration, thereby gradually decreasing its speed from a target speed to a third speed. In this embodiment, the second reverse acceleration is negative; therefore, during this stage, the motor undergoes variable deceleration. The magnitude of the second acceleration may or may not be equal to the magnitude of the first acceleration; this is not limited here. Similarly, optionally, the motor's speed curve and acceleration curve are set to be continuous and smooth to ensure the motor remains stable during deceleration and avoid vibration. For example, the motor's speed curve is V = t (-1 / 2) Clearly, the acceleration curve of the motor is a = -1 / 2t. (-3 / 2)In this case, the motor's speed and acceleration curves are continuous and smooth, resulting in minimal vibration during deceleration. In this embodiment, the motor's speed and acceleration curves can also be any other curves that meet the conditions, namely, the speed increases from the target speed to the third speed, and the acceleration increases from 0 to the reverse second acceleration. During this stage, the current motor speed can be detected in real time, and the difference between the current speed and the third speed can be calculated. Based on this difference, closed-loop speed control of the motor can be performed. The method for obtaining the motor speed is the same as the method used in the constant torque drive stage and flexible torque drive stage in the first embodiment, and will not be elaborated here.

[0093] The drive motor gradually reduces its speed to the fourth speed with a reverse second acceleration. In other words, during this stage, the motor undergoes uniform deceleration with a reverse second acceleration.

[0094] The motor is driven so that its acceleration gradually decreases from the second reverse acceleration to zero, and its speed gradually decreases until it stops. That is, in this stage, the motor undergoes variable deceleration with increasing reverse acceleration. Similarly, optionally, the motor's speed curve and acceleration curve are set to be continuous and smooth to ensure the motor remains stable during deceleration and avoid vibration. For example, the motor's speed curve is V = t... -3 Clearly, the acceleration curve of the motor is a = -3t. 2 In this case, the motor's speed and acceleration curves are continuous and smooth, resulting in minimal vibration during deceleration. In this embodiment, the motor's speed and acceleration curves can also be any other curves that satisfy the condition that the speed decreases from the fourth speed to 0, and the acceleration decreases from the reverse second acceleration to 0.

[0095] Since the motor is already in a low-speed stage (the motor speed is less than the preset threshold), the rotor position signal of the motor can be obtained in real time by the high-frequency current injection method. The current speed of the motor can be obtained based on the rotor position signal, the difference between the current speed of the motor and zero can be calculated, and the motor speed can be controlled in a closed loop based on the difference, so that the acceleration of the motor decreases from the second reverse acceleration to zero, and the motor speed decreases from the fourth speed to zero.

[0096] In a specific application scenario, see Figure 7 , Figure 7 This is a schematic diagram of a motor operating speed curve according to one embodiment. In this embodiment, when the motor reaches the target speed, it moves at the target speed for a preset time period. Figure 7 As shown, without loss of generality, assume that the motor's speed curve during the high torque phase (0-t1) is V = t. 3During this phase, the motor undergoes variable acceleration with increasing acceleration, changing from 0 to the first speed v1. In the constant torque drive phase (t1-t2), the motor speed curve is V = a1t, where a1 (not shown in the figure) is the motor's first acceleration. In this phase, the motor undergoes uniform acceleration with an acceleration of a1, changing from the first speed v1 to the second speed v2. In the flexible torque drive phase (t2-t3), the motor speed curve is V = t 1 / 2 During this stage, the motor undergoes variable acceleration with decreasing acceleration, and the motor speed changes from the second speed v2 to the target speed v3. In the t3-t4 stage, the motor moves at a constant speed at the target speed. In the t4-t5 stage, the motor's speed curve is V = t (-1 / 2) During this stage, the motor undergoes variable deceleration with increasing reverse acceleration, changing its speed from the target speed v3 to the third speed v4. In the t5-t6 stage, the motor undergoes uniform deceleration with a second reverse acceleration a2 (not shown in the figure), changing its speed from the third speed v4 to the fourth speed v5. In the t6-t7 stage, the motor's speed curve is V = t -3 During this stage, the motor undergoes a variable deceleration motion with increased reverse acceleration, and the speed changes from the fourth speed v5 to 0.

[0097] In this embodiment, v1 = v5 and v2 = v4.

[0098] In summary, the motor driving method for the food processor provided in this application first obtains the target speed, and then drives the motor in stages to reach the target speed based on the target speed. The stages include a high torque driving stage, a constant torque driving stage, and a flexible torque driving stage. In this way, the motor vibration, unstable start-up, and high noise caused by a single input when driving the motor are avoided.

[0099] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of modules or units described above is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0100] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0101] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0102] If the integrated units in the other embodiments described above are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0103] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A method for driving a motor in a food processor, characterized in that, include: Obtain the target rotational speed; A first acceleration, a first rotational speed, and a second rotational speed are determined based on the target rotational speed, wherein the first acceleration is the optimal acceleration that matches the target rotational speed. According to the target speed, the motor is driven in stages to reach the target speed, wherein the stages sequentially include a high torque drive stage, a constant torque drive stage, and a flexible torque drive stage; The motor is driven to operate at the target speed for a preset time period, and after the preset time period, the motor is driven to gradually decrease from the target speed to stop; The step of driving the motor in stages to reach the target speed according to the target speed includes: During the high-torque drive phase, the motor is driven so that the acceleration of the motor gradually increases from 0 to the first acceleration, and the rotational speed of the motor gradually increases from 0 to the first rotational speed; and during the high-torque drive phase, the current rotational speed of the motor is detected using a high-frequency current injection method. During the constant torque drive phase, the motor is driven to gradually increase its speed to the second speed with constant torque at the first acceleration; During the flexible torque drive phase, the motor is driven so that the acceleration of the motor gradually decreases from the first acceleration to 0 and the rotational speed of the motor reaches the target rotational speed; The process of driving the motor to gradually decrease from the target speed to stop includes: The motor is driven to gradually increase its acceleration from 0 to a second reverse acceleration, thereby gradually decreasing its rotational speed from the target speed to a third speed; the motor is then driven to gradually decrease its rotational speed to a fourth speed with the second reverse acceleration. The motor is driven so that the acceleration of the motor gradually decreases from the reverse second acceleration to 0 and the rotational speed of the motor gradually decreases until it stops.

2. The driving method according to claim 1, characterized in that, Also includes: Detect the current speed of the motor; The acceleration of the motor is adaptively adjusted to perform torque compensation based on the current speed, the first speed, the second speed, and the target speed.

3. The driving method according to claim 1, characterized in that, The first rotational speed is in the range of 30 to 300 rpm, and the second rotational speed is in the range of 300 to 3500 rpm.

4. A food processor, characterized in that, The device includes a motor, a drive circuit, and a control circuit, wherein the drive circuit is connected to the motor to drive the motor, and the control circuit is connected to the drive circuit to provide control signals to the drive circuit, thereby controlling the drive circuit to drive the motor to perform the driving method as described in any one of claims 1-3.

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