CN112448641B - Motor rotating speed control method for food processing machine - Google Patents

Abstract

The invention provides a motor speed control method for a food processing machine. The motor speed control method includes: obtaining the actual speed of the motor; The AC half-wave is evenly divided by multiple chopping points; the AC zero-crossing point is obtained, the actual speed of the motor is compared with the preset speed, and the target chopping corresponding to the AC half-wave is determined according to the comparison result between the actual speed of the motor and the preset speed Wave point, and control the conduction from the target chopping point of the AC half-wave. In the scheme, by evenly dividing the AC half-wave, when modulating the motor speed of the food processor, it can achieve infinite power Level smooth adjustment, that is, equal power control, avoiding the sudden rise and fall of the motor speed of the food processor, and improving the user experience.

Description

Motor speed control method for food processing machine

technical field

The invention relates to the technical field of food processing, in particular to a motor speed control method for a food processing machine.

Background technique

With the prevalence of the concept of health preservation, food processors such as wall breakers, mixers, mills, meat grinders, and juice machines are playing an increasingly important role in people's lives. Consumers follow the trend to buy food processing machines The machine can meet the processing needs of consumers for different food materials. With the continuous upgrading of products, the performance and functional requirements of consumers for food processors are also constantly improving.

At present, the adjustment and control of the power of the AC power of the food processor is basically controlled by the relay and the thyristor. Specifically, the existing scheme is mainly to compare the actual power and the target power of the food processor, and adjust the conduction of the thyristor by comparing the structure. There are two main disadvantages of the existing scheme. One is that the power adjustment accuracy of the food processor is not high, because the existing scheme is based on the fuzzy adjustment of the conduction time of the thyristor according to the comparison result of the actual power and the target power. It is also impossible to achieve stepless smooth adjustment of power, that is, equal power control, resulting in sudden high and low power of the food processor. When adjusting the motor, the speed of the motor is high and low, and the speed control is poor. It leads to loud noise and poor consumer experience. When controlling the heating device, the temperature fluctuates up and down, resulting in poor food processing effect; the second is the ambiguity of the conduction time of the thyristor according to the comparison between the actual power and the target power. The adjustment occupies the terminal of the control unit for a long time, which reduces the processing speed of the control unit, affects the real-time operation of the food processor, and further affects the user's operating experience of the food processor.

Contents of the invention

The present invention aims to solve one of the technical problems in the above-mentioned technologies at least to a certain extent. In order to overcome the shortcomings and deficiencies in the prior art, the present invention provides a motor speed control method for food processing machines.

In order to achieve the above object, the present invention adopts the following technical solution: a motor speed control method for a food processing machine, the motor speed control method comprising:

Obtain the actual speed of the motor;

Determine the number of chopping points of the AC half-wave according to the power modulation accuracy and the total power of the AC half-wave, and evenly divide the AC half-wave through multiple chopping points;

Obtain the zero-crossing point of the alternating current, compare the actual speed of the motor with the preset speed, determine the target chopping point corresponding to the half-wave of the alternating current according to the comparison result between the actual speed of the motor and the preset speed, and control the switching point from the half-wave of the alternating current The target chopping point starts conduction.

Preferably, the number of chopping points of the alternating current half-wave is determined according to the power modulation accuracy and the total power of the alternating current half-wave, and evenly dividing the alternating current half-wave through a plurality of chopping points includes: dividing the plurality of chopping points into the The alternating current half-wave is divided into equal power, so that the difference between the work done by two adjacent chopping points is equal.

Preferably, multiple chopping points are divided into equal powers for the alternating current half-wave, so that the difference between the work done by two adjacent chopping points is equal to satisfy the relationship: P _t(i+1) -P _ti =P _ti -P _t(i-1) , where ti is the chopping point, t (i-1), ti and ti, t(i+1) are adjacent chopping points respectively, P _t(i-1) , P _ti , P _t(i+1) are the power at the chopping point, respectively.

Preferably, the number of chopping points of the alternating current half wave is determined according to the power modulation accuracy and the total power of the alternating current half wave, and evenly dividing the alternating current half wave through a plurality of chopping points includes: calculating the preset load within the alternating current half wave The total power of the AC half-wave is obtained by integrating the power with respect to time, and a mapping relationship is established according to the total power of the AC half-wave and the power modulation accuracy to determine the chopping points of the AC half-wave number.

Preferably, comparing the actual speed of the motor with the preset speed, and determining the target chopping point corresponding to the half-wave of the alternating current according to the comparison result between the actual speed of the motor and the preset speed includes: calculating the difference between the actual speed of the motor and the preset speed , using the difference to determine the target chopping point corresponding to the alternating current half-wave.

Preferably, the calculating the difference between the actual rotation speed and the preset rotation speed of the motor, and determining the target chopping point corresponding to the half-wave of the alternating current through the difference includes: calculating the target total output through the difference, and establishing the The mapping relationship between the target total output and the target chopping point is used to determine the target chopping point corresponding to the AC half-wave.

Preferably, the calculation of the target total output through the difference, and establishing the mapping relationship between the target total output and the target chopping point include: based on the difference, calculating the incremental PID of the current total output Adjust the amount to obtain the target total output, and process the target total output per unit to establish a mapping relationship between the target total output and the target chopping point.

其中，K为目标总输出与目标斩波点的映射系数，X为目标斩波点。Preferably, the incremental adjustment of the current total output is calculated by the incremental PID to satisfy the relational expression: D _{j =} Kp*(Err_Cur-Err_Last)+Ki*Err_Cur, D _{tg =} D _{c +} D _j , where Err_Cur = Sref- Scur, Sref is the preset speed, Scur is the actual speed, Err_Cur is the difference between the preset speed and the actual speed, Err_Last is the difference between the preset speed and the actual speed in the previous adjustment of the AC power, Kp is the proportional adjustment coefficient, and Ki is Integral adjustment coefficient, D _j is the incremental adjustment amount, D _c is the current total output, D _tg is the target total output, and the target total output is processed per unit to establish the target total output and the target chopping point The mapping relationship of satisfies the relation:

Among them, K is the mapping coefficient between the target total output and the target chopping point, and X is the target chopping point.

Preferably, controlling the conduction from the target chopping point of the alternating current half-wave includes: taking the zero-crossing point of the alternating current as a time reference point, timing to the target chopping point of the current half-wave, so that from the alternating current half-wave The target chopping point of the start of conduction.

Preferably, the motor speed control method further includes: taking the target chopping point as a reference point, setting the value to the set value of the alternating current half-wave pulse width to close the circuit.

The above-mentioned technical solution of the present application has the following beneficial effects:

In the present invention, a motor speed control method for a food processor is provided. Specifically, in the scheme, the number of chopping points of the AC half-wave is determined according to the power modulation accuracy required by the food processor and the total power of the AC half-wave. Multiple chopping points evenly divide the AC half-wave, specifically, multiple chopping points divide the AC half-wave with equal power, so that the difference between the work done by two adjacent chopping points is equal, and calculate the food processing The difference between the machine preset speed and the actual speed, based on the difference, the incremental adjustment amount of the current total output is calculated by incremental PID to obtain the target total output, so that by establishing the target total output and the target The mapping relationship of the chopping point determines the target chopping point. When modulating the speed of the food processor, it can achieve stepless smooth adjustment of the speed, that is, equal speed and equal power control, to avoid sudden high speed of the food processor. In addition, the present invention uses an incremental PID algorithm to calculate the incremental adjustment amount. After interference occurs during the working process of the food processing machine, the incremental PID algorithm can avoid the sudden increase of the adjustment amount and avoid power failure. The problem of large fluctuations. Specifically, when adjusting the motor, because the difference in work between adjacent chopping points is equal, that is, the division of equal work, the speed of the motor can be adjusted more smoothly, and the speed of the motor can be avoided from fluctuating. The problem of high noise caused by speed control improves user experience.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present application. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a flowchart of a power modulation method for a food processor according to Embodiment 1 of the present invention.

Fig. 2 is a schematic diagram of division of alternating current half-wave chopping points according to Embodiment 1 of the present invention.

Fig. 3 is a flowchart of a power modulation method for a food processor according to Embodiment 2 of the present invention.

Fig. 4 is a time table of the alternating current half-wave chopping points according to the second embodiment of the present invention.

Fig. 5 is a flowchart of a power modulation method for a food processor according to Embodiment 3 of the present invention.

FIG. 6 is a flow chart of determining the target chopping point corresponding to the alternating current half-wave according to the third embodiment of the present invention.

Fig. 7 is a flow chart of calculating the target total output and establishing the mapping relationship between the target total output and the target chopping point according to the third embodiment of the present invention.

Fig. 8 is a schematic block diagram of the main components of the food processing machine according to the fourth embodiment of the present invention.

Fig. 9 is a flow chart of a motor power modulation method for a food processing machine according to Embodiment 4 of the present invention.

Fig. 10 is a flow chart of motor power modulation according to Embodiment 4 of the present invention.

Fig. 11 is a schematic block diagram of the main components of the food processing machine according to the fifth embodiment of the present invention.

Fig. 12 is a flow chart of the power modulation method of the heating device for the food processor according to the fifth embodiment of the present invention.

Fig. 13 is a flowchart of the power modulation of the heating device according to the fifth embodiment of the present invention.

Fig. 14 is a schematic block diagram of the main components of the food processing machine according to the fifth embodiment of the present invention.

Fig. 15 is a schematic diagram of the circuit of the main components of the food processing machine according to the fifth embodiment of the present invention.

The labels corresponding to the names of the components in the figure are as follows:

10. EMC module; 20. Switching power supply module; 30. Control module; 40. Zero-crossing detection module; 50. Thyristor module; 60. Voltage detection module.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

It is to be understood that the embodiments merely represent possible variations, that individual components and functions are optional, and that the order of operations may be varied unless explicitly required, that the terms "comprising," "comprising," or any other term used herein Variations are intended to cover a non-exclusive inclusion, so that a process, method, or device comprising a series of elements includes not only those elements, but also includes other elements not explicitly listed, and the embodiments of the present invention will be described below in conjunction with the accompanying drawings Detailed description. It should be noted that, in the case of no conflict, the embodiments in the application and the features in the embodiments can be combined arbitrarily with each other, and the logical sequence is shown in the flowchart, but in some cases, it can be different from The sequence herein performs the steps shown or described in sequence.

Embodiment one

As shown in FIG. 1, in an exemplary embodiment of the present invention, this embodiment provides a motor speed control method for a food processing machine. As shown in FIG. 1, the power modulation method for the food processing machine includes steps 101 and step 102.

Step 101: Determine the number of chopping points of the AC half-wave according to the power modulation accuracy and the total power of the AC half-wave, and evenly divide the AC half-wave through multiple chopping points;

When adjusting the power of the food processor, in order to quickly and accurately realize the modulation of the power of the food processor, improve the accuracy of the power modulation, and avoid fluctuations in the power of the food processor, and fluctuations around the target power situation.

In the scheme of this embodiment, the number of chopping points of the AC half-wave is determined according to the power modulation accuracy and the total power of the AC half-wave. The power modulation accuracy refers to the minimum unit of power adjustment when adjusting the power of the food processor. Smoothness and power modulation accuracy can be set according to requirements. In this solution, including but not limited to calculating the total power of the preset load, that is, the total power done by a specific load in the AC half-wave can be calculated, combined with the power modulation accuracy , divide the AC half-wave to determine the number of chopping points in the AC half-wave.

Evenly divide the AC half-wave through multiple chopping points. By evenly dividing the AC half-wave, when adjusting the power, you can select a uniformly divided chopping point as the target chopping of the current AC half-wave according to actual needs. The wave point can realize the smooth modulation of the power.

It should be noted that the uniform division of the AC half-wave by the chopping point includes but is not limited to the following methods: First, the program setting of the food processor is completed before leaving the factory, that is, according to the power adjustment requirements of the food processor when it leaves the factory, it is completed through multiple The first chopping point evenly divides the AC half-wave. When the food processor is working, the target chopping point is selected by looking up the table according to the comparison result between the actual power and the target power; Determine the number of chopping points, and evenly divide the AC half-wave through multiple chopping points.

It should be noted that because the power requirements of different food processing functions vary greatly, the power modulation accuracy described in this scheme can be set to different power modulation accuracy according to the power requirements of different food processing functions. This power modulation accuracy The setting scheme can improve the efficiency of power modulation during power modulation, and it is convenient to quickly modulate the power of the food processor to the target power.

Step 102: Obtain the zero-crossing point of the alternating current, determine the target chopping point corresponding to the half-wave of the alternating current according to the power requirement of the food processor, and control conduction from the target chopping point of the half-wave of the alternating current.

According to the power requirements of the food processor, determine the target chopping point corresponding to the AC half-wave, mainly including three situations: the current power is too small, the power needs to be increased; the current power is too large, the power needs to be reduced; the current power It is the target power, keep the current power constant, and if you keep the current power constant, you don’t need to adjust the chopping point, just use the chopping point of the last AC half-wave as the target chopping point of this AC half-wave, set It is necessary to adjust the chopping point to increase or decrease the power, and to determine a suitable target chopping point for the current AC half-wave specifically according to the magnitude of the power increase or decrease.

Wherein, the alternating current zero-crossing point is the zero-crossing point of the alternating current half-wave to be executed, and after determining the appropriate target chopping point of the current alternating current half-wave, the control starts conduction from the target chopping point of the alternating current half-wave, that is, through the alternating current The chopper control realizes the modulation of power.

Determine the number of chopping points of the AC half-wave according to the power modulation accuracy and the total power of the AC half-wave, and evenly divide the AC half-wave through multiple chopping points, including: performing equalization on the AC half-wave by multiple chopping points The power is divided so that the difference in work done by two adjacent chopping points is equal.

Specifically, the division of the chopping point to the AC half-wave affects the power modulation scheme and the smoothness of the power modulation. The smoothness of the power modulation mentioned here refers to the power and division that need to be adjusted when the actual power of the food processor is modulated. There is a uniform mapping relationship between the chopping points, so that each time the power is adjusted, the unit power can be adjusted. In this scheme, in order to ensure the linearity of the power modulation, multiple chopping points are used for the AC half-wave Equal power division is carried out, that is, conduction is conducted from two adjacent chopping points respectively, and the difference between the work done by any two adjacent chopping points is a fixed value.

即约为311V，相邻两个斩波点做功的差值相等满足关系式：Specifically, as shown in Figure 2, the horizontal axis in Figure 2 is time, the vertical axis is amplitude, and the vertical 1 in the vertical axis represents the peak value of the mains power, and the specific value is

That is, it is about 311V, and the difference between the work done by two adjacent chopping points is equal to satisfy the relation:

P _t(i+1) -P _ti ＝P _ti -P _t(i-1) (Formula 1)

Among them, ti is the chopping point, t(i-1), ti and ti, t(i+1) are the adjacent chopping points respectively, P _t(i-1) , P _ti , P _{t(i+1 )} are the power of the chopping point respectively, as shown in Equation 1, the difference of the power of adjacent chopping points is a constant value.

Embodiment two

In this embodiment, the mapping relationship is established by the total power of the alternating current half-wave and the power modulation accuracy to determine the number of alternating current half-wave chopping points, as shown in Figure 3. In the scheme of this embodiment, the power modulation method used by the food processor is based on The accuracy and the total power of the AC half-wave determine the number of chopping points of the AC half-wave, and evenly dividing the AC half-wave through multiple chopping points includes steps 201 and 202 .

Step 201: Calculate the power of the preset load in the AC half-wave, and integrate the power with time to obtain the total work of the AC half-wave.

Most of the existing food processing machines are powered by 220V, 50HZ mains electricity. In this embodiment, 220V, 50HZ mains electricity is used as an example, and the AC waveform function satisfies Equation 2.

Among them, U(t) is the AC voltage, and t is the time.

Therefore, for the preset load, it is assumed that the load resistance is R, so the total work of the half-wave AC described in this embodiment is the total work done by the preset load in the half-wave of the AC, then for the half-wave interval of the AC t∈[a ,b], 0≤t≤0.01, and the time unit is S, then the work done by the preset load satisfies Equation 3.

Wherein, W(t) is the work done in the time t, and P is the power of the preset load whose resistance is R in the time t.

Integral transformation of formula 3 and dequantification can be obtained:

W(a,b)＝b/2-a/2+(sin(200*π*a)/400-sin(200*π*b)/400)/π (Formula 4)

Step 202: Establish a mapping relationship according to the total power of the AC half-wave and the power modulation accuracy to determine the number of chopping points of the AC half-wave.

In this embodiment, the power adjustment accuracy is determined by the total power of the half-wave alternating current combined with the power modulation requirements of different processing techniques of the food processing machine, so as to establish a mapping relationship between the total power of the half-wave alternating current and the power modulation accuracy, that is, according to The accuracy of power modulation divides the AC half-wave equally through the chopping point, assuming that the equal fraction of the AC half-wave is n+1 (that is, the number of chopping points is n), then the calculation method of the power value W _n of each equal division is :

W _n =W(0.0,0.01)/n (Formula 5)

0.01 in Formula 5 means that the time of the AC half-wave is 0.01S.

In this way, formula 4 and formula 5 are solved to calculate each chopping point, namely:

W(0,x ₀ )＝W _n ＝W(0.0,0.01)/n (Formula 6)

The first chopping point x ₀ can be calculated, and similarly, the second chopping point x ₁ can be calculated through Equation 7.

W(x ₀ ,x ₁ )=W(0.0,0.01)/n (Formula 7)

Among them, W(x0, x1) is the work done by the preset load within the time range from the first chopping point to the second chopping point.

Similarly, the nth chopping point x _n-1 can be calculated sequentially, and the calculation results of each chopping point are shown in Figure 4, and the table shows the chopping time in the AC half-wave.

It is understandable that the number of chopping points can also be directly set according to the power modulation accuracy, such as setting the number of chopping points to 300, 500, 800, 1200, 1500, 1800, 2000 etc.

Embodiment Three

The difference between Embodiment 1 and Embodiment 2 of this embodiment is that, on the basis of Embodiment 1 and Embodiment 2, it is given to determine the alternating current half-wave Example scheme of the corresponding target chopping point.

As shown in Fig. 5, the power modulation method for the food processing machine in this embodiment includes step 301 and step 302.

Step 301: Calculate the difference between the preset power and the actual power of the food processor.

Specifically, in this embodiment, voltage detection can be realized through the voltage detection module of the food processor. For the preset load R, the actual power of the preset load can be obtained. When the food processor is working, different processing stages have different power Requirements, and then can calculate the difference between the preset power and the actual power under the current working state of the food processor.

It should be noted that there are many ways to obtain the actual power of the food processor, including but not limited to voltage detection, for example, the actual power of the food processor can be obtained through current detection.

Step 302: Determine the target chopping point corresponding to the AC half-wave through the difference.

The difference between the preset power and the actual power is the power to be adjusted, and the power of the food processor can be adjusted by corresponding the difference with the target chopping point through a preset algorithm.

Specifically, as shown in FIG. 6 , determining the target chopping point corresponding to the AC half-wave through the difference includes step 401 and step 402 .

Step 401: Calculate the target total output through the difference, and establish a mapping relationship between the target total output and the target chopping point.

The target total output of the current half-wave is determined by the difference between the preset power and the actual power and the preset adjustment method is used, and the calculated target total output and chopping point are calculated using a certain corresponding algorithm to achieve the total output and target chopping A mapping relationship is established between the points.

It should be noted that there is no direct equal or unequal relationship between the target total output and the preset power. The target total output is determined according to the difference between the preset power and the actual power combined with a certain adjustment method, and the preset power is The power set or required in the working state of the food processor.

Specifically, as shown in FIG. 7 , calculating the target total output through the above difference, and establishing the mapping relationship between the target total output and the target chopping point include steps 501 and 502 .

Step 501: Based on the difference, calculate the incremental adjustment amount of the current total output through incremental PID to obtain the target total output.

In the processing of food processing machines, the required power (that is, the real-time preset power) is changing. In this solution, based on the difference between the preset power and the actual power, the incremental PID algorithm is used to calculate the increment of the actual power that needs to be superimposed. The increment described here can be to increase power or to decrease power, that is, the increment can be positive or negative, and the target total output is the sum of the current total output and the incremental adjustment value, using incremental The advantages of PID algorithm to calculate the incremental adjustment amount are: if there is interference during the working process of the food processor, the incremental PID algorithm can avoid excessive fluctuations in the speed adjustment and avoid affecting the user experience of the product. In addition, it can also ensure that the product service life.

Specifically, the incremental adjustment of the current total output through the incremental PID calculation satisfies the relational expression:

D _j =Kp*(Err_Cur-Err_Last)+Ki*Err_Cur (Formula 8)

D _tg ＝ D _{c +} D _j (Formula 9)

Among them, Err_Cur＝Wref-Wcur, Wref is the preset power, Wcur is the actual power, Err_Cur is the difference between the preset power and the actual power, Err_Last is the difference between the preset power and the actual power in the previous adjustment of the AC, and Kp is Proportional adjustment coefficient, Ki is the integral adjustment coefficient, D _j is the incremental adjustment amount, D _c is the current total output, and D _tg is the target total output.

Step 502: Process the target total output per unit to establish a mapping relationship between the target total output and the target chopping point.

其中，K为目标总输出与目标斩波点的映射系数，X 为目标斩波点。The target total output is processed per unit to establish the mapping relationship between the target total output and the target chopping point to satisfy the relational expression:

Among them, K is the mapping coefficient between the target total output and the target chopping point, and X is the target chopping point.

It should be noted that there are many ways to establish the mapping relationship between the target total output and the target chopping point, and it is not limited to establishing the mapping relationship between the target total output and the target chopping point through the mapping coefficient K described in this article.

Step 402: Determine the target chopping point corresponding to the AC half-wave.

By calculating the target chopping point corresponding to the target total output, X is calculated, and X is the target chopping point corresponding to the current AC half-wave.

It can be understood that there are many ways to determine the target chopping point, and it is not limited to the calculation of the difference between the preset power and the actual power of the food processor described in this embodiment. In the control of the food processor, There are many uses of power modulation, such as the adjustment of the motor speed, the control of the temperature of the heating device, etc. Therefore, the power to the motor and the heating device can be adjusted based on the difference between the set value and the actual value of the parameters such as the speed and temperature.

Embodiment Four

The difference between the first embodiment, the second embodiment, and the third embodiment of this embodiment is that, on the basis of the first embodiment, the second embodiment, and the third embodiment, this embodiment provides a scheme for motor power modulation.

The food processor drives the stirrer of the food processor to stir and process the ingredients through the motor. The power modulation of the motor determines the change of the motor speed, including the increase or decrease of the motor speed, the magnitude and speed of the increase or decrease, etc., such as The high and low changes in motor speed not only cause loud noise and poor food processing effect, but also directly affect the user's intuitive use experience.

As shown in Figure 8, Figure 8 is a schematic block diagram of the main components of the food processing machine, the food processing machine includes a voltage detection module 60, a zero-crossing detection module 40 for detecting the zero-crossing point of alternating current, an EMC module 10, a switching power supply module 20, a control The module 30, the motor and the thyristor module 50 for controlling the motor, the food processing machine is provided with a speed measuring module for measuring the rotational speed of the motor.

As shown in Figure 9, the motor power modulation method for food processors includes steps 601, 602 and 603.

Step 601: Calculate the rotational speed difference between the actual rotational speed of the motor and the preset rotational speed, and calculate the target total output through the rotational speed difference.

As shown in Figure 10, the motor speed is obtained through the speed detection module, the speed difference between the actual speed of the motor and the preset speed is calculated, and the preset adjustment method is used to determine the target total output of the current half wave. In this embodiment, in In the processing of food processing machines, the required speed (that is, the real-time preset speed) is changing. In this solution, based on the difference between the preset speed and the actual speed, the incremental PID algorithm is used to calculate the actual speed through the PID control module. Increment, the increment mentioned here can be to increase the speed or to reduce the speed, that is, the increment can be positive or negative, and the target total output is the sum of the current total output and the incremental adjustment. The advantages of incremental PID algorithm to calculate the incremental adjustment amount are: if there is interference during the working process of the food processor, the incremental PID algorithm can avoid excessive fluctuations in speed adjustment and avoid affecting the user experience of the product. In addition, it can also Can guarantee the service life of the product.

其中，K为目标总输出与目标斩波点的映射系数，X为目标斩波点。Specifically, D _j =Kp*(Err_Cur-Err_Last)+Ki*Err_Cur, D _tg =D _c+ D _j , where Err_Cur=Sref-Scur, Sref is the preset speed, Scur is the actual speed, Err_Cur is the preset speed and the actual speed difference, Err_Last is the difference between the preset speed and the actual speed in the previous adjustment of the AC, Kp is the proportional adjustment coefficient, Ki is the integral adjustment coefficient, D _j is the incremental adjustment amount, and D _c is the current total output , D _tg is the target total output, and the target total output is processed per unit to establish the mapping relationship between the target total output and the target chopping point to satisfy the relational expression:

Among them, K is the mapping coefficient between the target total output and the target chopping point, and X is the target chopping point.

It should be noted that there is no direct equal or unequal relationship between the target total output and the preset speed. The target total output is determined according to the difference between the preset speed and the actual speed combined with a certain adjustment method. The set or required speed of the food processor under working conditions.

Step 602: Establish a mapping relationship between the target total output and the target chopping point, so as to determine the target chopping point corresponding to the AC half-wave.

其中，K为目标总输出与目标斩波点的映射系数，X 为目标斩波点。The target total output is processed per unit to establish the mapping relationship between the target total output and the target chopping point to satisfy the relational expression:

Among them, K is the mapping coefficient between the target total output and the target chopping point, and X is the target chopping point.

It should be noted that there are many ways to establish the mapping relationship between the target total output and the target chopping point, and it is not limited to establishing the mapping relationship between the target total output and the target chopping point through the mapping coefficient K described in this article.

Step 603: Taking the zero-crossing point of the alternating current as a time reference point, timing to the target chopping point of the current half-wave, so as to start conduction from the target chopping point of the alternating current half-wave.

The food processing machine obtains the zero-crossing point through the zero-crossing detection module 40, and takes the zero-crossing point as the time reference point, and uses the timer T1 to time to the target chopping point X of the current half-wave. The target chopping point is turned on, and the timer T1=k is assigned, k is the pulse width of the driving thyristor waveform, with the target chopping point as the reference point, set the value to the AC half-wave pulse width setting value to close the circuit, timing When the time is up, the thyristor will be turned off, and if the time is not up, the control port will control the opening of the thyristor to realize the control of the pulse width.

It should be noted that the speed measuring module in this embodiment includes but is not limited to a bipolar latch type Hall sensor and a magnetic ring arranged on the rotating speed, and the magnetic ring has 3 polarities or more.

Embodiment five

The difference between the first embodiment, the second embodiment, and the third embodiment of this embodiment is that, on the basis of the first embodiment, the second embodiment, and the third embodiment, this embodiment provides a scheme for modulating the power of the heating device.

As shown in Figure 11, the food processing machine includes a voltage detection module 60, a zero-crossing detection module 40 for detecting the zero-crossing point of alternating current, an EMC module 10, a switching power supply module 20, a control module 30, and a controllable control module for controlling the heating device. The silicon module 50, the food processing machine heats the food through the heating device, the heating power of the heating device determines the temperature change, and the temperature change directly affects the heating effect of the food.

As shown in FIG. 12 , the modulation of the power of the heating device includes step 701 , step 702 and step 703 .

Step 701: Calculate the target total output based on the temperature difference between the actual temperature of the food heated by the heating device and the preset temperature.

As shown in Figure 13, the food is heated by the heating device, and the food processor is also provided with a temperature detection device. The temperature of the food is obtained through the temperature detection device, and the temperature difference between the actual temperature of the food and the preset temperature is calculated, and the preset temperature is used. The adjustment method determines the target total output of the current half-wave. In this embodiment, the required temperature (i.e., the real-time preset temperature) changes during the processing of the food processor. In this solution, the actual temperature and the preset temperature of the ingredients are used. The temperature difference value of the PID control module adopts the incremental PID algorithm to calculate the increment of the actual temperature that needs to be superimposed. The increment mentioned here can be to increase the temperature or to decrease the temperature, that is, the increment can be positive or can be If it is a negative value, the target total output is the sum of the current total output and the incremental adjustment amount. The advantages of using the incremental PID algorithm to calculate the incremental adjustment amount are: if there is interference during the working process of the food processor, use the incremental PID The algorithm can avoid excessive fluctuations in temperature adjustment, avoid affecting the user experience of the product, and in addition, it can also ensure the service life of the product.

It should be noted that there is no direct equal or unequal relationship between the target total output and the preset temperature. The target total output is determined according to the difference between the preset temperature and the actual temperature combined with a certain adjustment method, and the preset temperature is the current The temperature set or required when the food processor is working.

Step 702: Establish a mapping relationship between the target total output and the chopping point, so as to determine the target chopping point corresponding to the AC half-wave.

其中，K为目标总输出与目标斩波点的映射系数，X为目标斩波点。As shown in Figure 13, the target total output is processed per unit to establish the mapping relationship between the target total output and the target chopping point to satisfy the relational expression:

Among them, K is the mapping coefficient between the target total output and the target chopping point, and X is the target chopping point.

It should be noted that there are many ways to establish the mapping relationship between the target total output and the target chopping point, and it is not limited to establishing the mapping relationship between the target total output and the target chopping point through the mapping coefficient K described in this article.

Step 703: Taking the zero-crossing point of the alternating current as a time reference point, timing to the target chopping point of the current half-wave, so as to start conduction from the target chopping point of the alternating current half-wave.

As shown in Figure 13, the food processing machine obtains the zero-crossing point through the zero-crossing detection module 40, and uses the zero-crossing point as the time reference point, uses the timer T1 to time to the target chopping point X of the current half-wave, and interrupts when the time is up. Control the conduction from the target chopping point through the thyristor, and assign the timer T1=k, k is the pulse width of the driving thyristor waveform. When the timer time is up, the thyristor will be turned off. If the time is not up, the control port will be controlled to open. Controlled silicon to realize the control of the pulse width.

It can be understood that, as shown in Figure 14 and Figure 15, for food processors that require motors to provide power to stir ingredients and heat ingredients, such as wall breakers, soybean milk makers, etc., the above power modulation method can simultaneously heat the motor and heat The device performs power regulation.

For the sake of concise description, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered as within the scope of this specification.

Those skilled in the art should understand that the above-described embodiments only express several implementations of the present invention, and their descriptions are more specific and detailed. Although the implementations disclosed in the embodiments of the present invention are as above, the content is only for easy understanding The implementation mode adopted in the embodiment of the present invention is not intended to limit the embodiment of the present invention. Any person skilled in the field to which the embodiment of the present invention belongs can, without departing from the spirit and scope disclosed in the embodiment of the present invention, Any modifications and changes are made in the forms and details of the implementation, but the patent protection scope of the embodiments of the present invention must still be defined by the appended claims and their equivalents.

Claims (10)

1. A motor speed control method for a food processing machine, characterized in that, the motor speed control method comprises: Obtain the actual speed of the motor; Determine the number of chopping points of the AC half-wave according to the power modulation accuracy and the total power of the AC half-wave, divide the AC half-wave evenly through multiple chopping points, and equalize the power of the AC half-wave by multiple chopping points divide; Obtain the zero-crossing point of the alternating current, compare the actual speed of the motor with the preset speed, determine the target chopping point corresponding to the half-wave of the alternating current according to the comparison result between the actual speed of the motor and the preset speed, and control the switching point from the half-wave of the alternating current The target chopping point starts conduction. 2. The motor speed control method for food processing machines according to claim 1, characterized in that, the number of chopping points of the alternating current half-wave is determined according to the power modulation accuracy and the alternating current half-wave total work, and a plurality of chopping points Evenly dividing the alternating current half-wave by the wave point includes: making the work difference of two adjacent chopping points equal. 3. The method for controlling the motor speed of a food processor according to claim 2, wherein a plurality of chopping points are used to divide the alternating current half-wave into equal power, so that two adjacent chopping points do work. The difference between equal to satisfy the relationship: P _t(i+1) -P _ti =P _ti -P _t(i-1) , where ti is the chopping point, and P _ti is the power of the chopping point. 4. The motor speed control method for food processing machines according to claim 1, characterized in that, the number of chopping points of the alternating current half-wave is determined according to the power modulation accuracy and the alternating current half-wave total work, and a plurality of chopping points Evenly dividing the alternating current half-wave by the wave point includes: calculating the power of the preset load in the alternating current half-wave, and obtaining the total work of the alternating current half-wave by integrating the power with respect to time, according to the total work sum of the alternating current half-wave The power modulation accuracy establishes a mapping relationship to determine the number of chopping points of the AC half-wave. 5. The motor speed control method for food processing machines according to claim 1, characterized in that, comparing the actual speed of the motor with the preset speed, and determining the half-wave alternating current according to the comparison result between the actual speed of the motor and the preset speed The corresponding target chopping point includes: calculating the difference between the actual rotation speed and the preset rotation speed of the motor, and determining the target chopping point corresponding to the alternating current half-wave through the difference. 6. The motor speed control method for food processing machines according to claim 5, characterized in that, the calculation of the difference between the actual speed of the motor and the preset speed is used to determine the corresponding half-wave of the alternating current through the difference. The target chopping point includes: calculating the target total output through the difference, and establishing a mapping relationship between the target total output and the target chopping point, so as to determine the target chopping point corresponding to the AC half-wave. 7. The motor speed control method for a food processing machine according to claim 6, wherein the target total output is calculated through the difference, and the mapping between the target total output and the target chopping point is established The relationship includes: based on the difference, calculate the incremental adjustment amount of the current total output through incremental PID to obtain the target total output, and process the target total output per unit to establish the target total output and the The mapping relationship of the target chopping point. 8. The method for controlling the motor speed of a food processing machine according to claim 7, wherein the incremental adjustment amount of the current total output by incremental PID calculation satisfies the relational expression: _Dj =Kp*(Err_Cur-Err_Last )+Ki*Err_Cur, D _tg ＝D _c +D _j , where, Err_Cur＝Sref-Scur, Sref is the preset speed, Scur is the actual speed, Err_Cur is the difference between the preset speed and the actual speed, Err_Last is the The difference between the preset speed and the actual speed in one adjustment, Kp is the proportional adjustment coefficient, Ki is the integral adjustment coefficient, D _j is the incremental adjustment amount, D _c is the current total output, D _tg is the target total output, for the The target total output is processed per unit to establish the mapping relationship between the target total output and the target chopping point to satisfy the relational expression:

Among them, K is the mapping coefficient between the target total output and the target chopping point, and X is the target chopping point. 9. The motor speed control method for a food processor according to any one of claims 1 to 8, characterized in that, controlling conduction from the target chopping point of the half-wave of the alternating current comprises: passing the alternating current through The zero point is a time reference point, which is timed to the target chopping point of the current half-wave, so that conduction starts from the target chopping point of the alternating current half-wave. 10. The motor speed control method for food processing machines according to claim 9, characterized in that the motor speed control method further comprises: taking the target chopping point as a reference point, setting the value to the AC half-wave pulse width setting set value to close the circuit.

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