阅读说明：本技术 基于模糊控制的永磁同步电主轴直接转矩调速方法 (Permanent magnet synchronous electric main shaft direct torque speed regulation method based on fuzzy control ) 是由 单文桃 李坤 潘玉成 蒋迪元 于 2020-03-31 设计创作，主要内容包括：本发明提供了一种基于模糊控制的永磁同步电主轴直接转矩调速方法,包括：获取永磁同步电主轴的实际转速；根据实际转速和永磁同步电主轴的设定转速得到永磁同步电主轴的实际转矩；获取永磁同步电主轴的定子三相电压和定子三相电流；根据定子三相电压和定子三相电流得到永磁同步电主轴的转矩估算值、定子磁链估算值和定子磁链角度；获取永磁同步电主轴的实际定子磁链；根据实际转矩和转矩估算值得到转矩偏差,并根据实际定子磁链和定子磁链估算值得到定子磁链偏差；基于模糊控制根据转矩偏差、定子磁链偏差和定子磁链角度得到调节信号。本发明能够减小永磁同步电主轴定子磁链和转矩的脉动,并能够提高永磁同步电主轴的动静态性能和抗干扰能力。(The invention provides a fuzzy control-based direct torque speed regulation method for a permanent magnet synchronous electric spindle, which comprises the following steps: acquiring the actual rotating speed of the permanent magnet synchronous electric spindle; obtaining the actual torque of the permanent magnet synchronous electric main shaft according to the actual rotating speed and the set rotating speed of the permanent magnet synchronous electric main shaft; obtaining stator three-phase voltage and stator three-phase current of the permanent magnet synchronous electric spindle; obtaining a torque estimated value, a stator flux linkage estimated value and a stator flux linkage angle of the permanent magnet synchronous electric main shaft according to the stator three-phase voltage and the stator three-phase current; acquiring an actual stator flux linkage of the permanent magnet synchronous electric spindle; obtaining torque deviation according to the actual torque and the torque estimated value, and obtaining stator flux linkage deviation according to the actual stator flux linkage and the stator flux linkage estimated value; an adjustment signal is obtained based on the fuzzy control according to the torque deviation, the stator flux linkage deviation and the stator flux linkage angle. The invention can reduce the pulsation of the stator flux linkage and the torque of the permanent magnet synchronous electric main shaft and can improve the dynamic and static performances and the anti-interference capability of the permanent magnet synchronous electric main shaft.)

1. A permanent magnet synchronous electric main shaft direct torque speed regulation method based on fuzzy control is characterized by comprising the following steps:

acquiring the actual rotating speed of the permanent magnet synchronous electric spindle;

obtaining the actual torque of the permanent magnet synchronous electric main shaft according to the actual rotating speed and the set rotating speed of the permanent magnet synchronous electric main shaft;

obtaining stator three-phase voltage and stator three-phase current of the permanent magnet synchronous electric spindle;

obtaining a torque estimated value, a stator flux linkage estimated value and a stator flux linkage angle of the permanent magnet synchronous electric main shaft according to the stator three-phase voltage and the stator three-phase current;

acquiring an actual stator flux linkage of the permanent magnet synchronous electric spindle;

obtaining a torque deviation according to the actual torque and the estimated torque value, and obtaining a stator flux deviation according to the actual stator flux and the estimated stator flux;

and obtaining an adjusting signal according to the torque deviation, the stator flux linkage deviation and the stator flux linkage angle based on fuzzy control so as to adjust the torque of the permanent magnet synchronous electric main shaft.

2. The fuzzy control-based permanent magnet synchronous electric spindle direct torque speed regulation method according to claim 1, wherein the actual torque of the permanent magnet synchronous electric spindle is obtained through a fuzzy adaptive PID regulation algorithm, and an input quantity of the fuzzy adaptive PID regulation algorithm comprises a difference value between the actual rotating speed and the set rotating speed.

3. The method for directly regulating the torque of the permanent magnet synchronous electric spindle based on the fuzzy control as claimed in claim 2, wherein obtaining the torque estimation value, the stator flux linkage estimation value and the stator flux linkage angle of the permanent magnet synchronous electric spindle in the two-phase stationary coordinate system according to the stator three-phase voltage and the stator three-phase current specifically comprises:

obtaining the stator voltage and the stator current of the permanent magnet synchronous electric spindle under a two-phase static coordinate system according to the stator three-phase voltage and the stator three-phase current;

obtaining a stator flux linkage component and a stator flux linkage estimated value of the permanent magnet synchronous electric spindle under the two-phase static coordinate system according to the stator voltage and the stator current;

obtaining the stator flux linkage angle according to the stator flux linkage component;

and obtaining the torque estimated value according to the stator flux linkage component and the stator current.

4. The method for directly regulating the torque of the permanent magnet synchronous electric spindle based on the fuzzy control as claimed in claim 3, wherein the stator voltage and the stator current of the permanent magnet synchronous electric spindle under the two-phase static coordinate system are obtained through Clark conversion, and the input quantities of the Clark conversion comprise the stator three-phase voltage and the stator three-phase current.

5. The fuzzy control based permanent magnet synchronous electric spindle direct torque speed regulation method according to claim 4, wherein obtaining an adjustment signal according to the torque deviation, the stator flux linkage deviation and the stator flux linkage angle based on fuzzy control comprises:

obtaining the direct axis stator voltage and the quadrature axis stator voltage of the permanent magnet synchronous electric spindle according to the torque deviation and the stator flux linkage deviation based on fuzzy control;

obtaining a stator flux linkage angle mapping value of the permanent magnet synchronous electric spindle according to the stator flux linkage angle based on fuzzy control;

obtaining the fuzzy stator voltage of the permanent magnet synchronous electric spindle under a two-phase static coordinate system according to the direct axis stator voltage, the quadrature axis stator voltage and the stator flux linkage angle mapping value;

and obtaining an adjusting signal of the permanent magnet synchronous electric spindle according to the fuzzy stator voltage under the two-phase static coordinate system.

6. The fuzzy control based permanent magnet synchronous electric spindle direct torque speed regulation method according to claim 5, wherein the torque deviation and the stator flux linkage deviation are fuzzified by adopting a membership value method.

7. The fuzzy control-based direct torque speed regulation method for the permanent magnet synchronous electric spindle according to claim 6, wherein the step of fuzzifying the stator flux linkage angle by using a membership value method comprises the following steps:

setting a fuzzy domain change interval and a fuzzy subset of the stator flux linkage angle;

dividing the fuzzy domain change interval of the stator flux linkage angle into a plurality of stator flux linkage sectors and marking the stator flux linkage sectors;

and mapping any angle of the ambiguity domain change interval of the stator flux linkage angle into one of the plurality of stator flux linkage sectors by adopting a symmetry principle.

8. The fuzzy control-based permanent magnet synchronous electric spindle direct torque speed regulation method according to claim 7, wherein the membership value method adopts a triangular membership function.

9. The method according to claim 5, wherein the fuzzy stator voltage of the PMSM in the two-phase static coordinate system is obtained through coordinate transformation, and the input variables of the coordinate transformation include the direct-axis stator voltage, the quadrature-axis stator voltage and the stator flux linkage angle mapping value.

10. The method according to claim 5, wherein the adjusting signal of the permanent magnet synchronous electric spindle is obtained by SVPWM algorithm transformation, and the input quantity of the SVPWM algorithm transformation comprises the fuzzy stator voltage in the two-phase stationary coordinate system.

Technical Field

The invention relates to the technical field of electric spindle control, in particular to a permanent magnet synchronous electric spindle direct torque speed regulation method based on fuzzy control.

Background

At present, a permanent magnet synchronous electric spindle is mostly adopted in a high-precision numerical control machine tool, and the permanent magnet synchronous electric spindle is widely applied to occasions with high precision and high reliability requirements mainly because the permanent magnet synchronous electric spindle has the advantages of simple structure, high power factor, good low-speed performance, small loss and the like. The permanent magnet synchronous electric spindle is usually controlled by adopting direct torque, but the commonly used direct torque control also has the problems of large torque pulsation and weak interference resistance.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the art described above. Therefore, the invention aims to provide a method for directly regulating the torque of a permanent magnet synchronous electric spindle based on fuzzy control, which can reduce the pulsation of a stator flux linkage and the torque of the permanent magnet synchronous electric spindle, and can improve the dynamic and static performances and the anti-interference capability of the permanent magnet synchronous electric spindle, thereby ensuring the precision of numerical control processing based on the permanent magnet synchronous electric spindle.

In order to achieve the above object, an embodiment of the present invention provides a method for directly adjusting a torque of a permanent magnet synchronous electric spindle based on fuzzy control, including the following steps: acquiring the actual rotating speed of the permanent magnet synchronous electric spindle; obtaining the actual torque of the permanent magnet synchronous electric main shaft according to the actual rotating speed and the set rotating speed of the permanent magnet synchronous electric main shaft; obtaining stator three-phase voltage and stator three-phase current of the permanent magnet synchronous electric spindle; obtaining a torque estimated value, a stator flux linkage estimated value and a stator flux linkage angle of the permanent magnet synchronous electric main shaft according to the stator three-phase voltage and the stator three-phase current; acquiring an actual stator flux linkage of the permanent magnet synchronous electric spindle; obtaining a torque deviation according to the actual torque and the estimated torque value, and obtaining a stator flux deviation according to the actual stator flux and the estimated stator flux; and obtaining an adjusting signal according to the torque deviation, the stator flux linkage deviation and the stator flux linkage angle based on fuzzy control so as to adjust the torque of the permanent magnet synchronous electric main shaft.

According to the method for directly regulating the torque of the permanent magnet synchronous electric main shaft based on the fuzzy control, firstly, the actual torque is obtained according to the actual rotating speed and the set rotating speed of the permanent magnet synchronous electric main shaft, secondly, the torque estimated value, the stator flux linkage estimated value and the stator flux linkage angle of the permanent magnet synchronous electric main shaft are obtained according to the stator three-phase voltage and the three-phase current of the permanent magnet synchronous electric main shaft, secondly, the torque deviation is obtained according to the actual torque and the torque estimated value, the stator flux linkage deviation is obtained according to the actual stator flux linkage and the stator flux linkage estimated value, and finally, the torque of the permanent magnet synchronous electric main shaft is regulated according to the torque deviation, the stator flux linkage deviation and the stator flux linkage angle based on the fuzzy control, so that the pulsation of the stator flux linkage and the torque of the permanent magnet synchronous electric main shaft can be reduced, and the dynamic and, therefore, the precision of numerical control machining based on the permanent magnet synchronous electric spindle can be ensured.

In addition, the method for adjusting the speed of the permanent magnet synchronous electric spindle direct torque based on the fuzzy control according to the above embodiment of the present invention may further have the following additional technical features:

according to one embodiment of the invention, the actual torque of the permanent magnet synchronous electric spindle is obtained through a fuzzy adaptive PID adjusting algorithm, and the input quantity of the fuzzy adaptive PID adjusting algorithm comprises the difference value of the actual rotating speed and the set rotating speed.

According to an embodiment of the present invention, obtaining an estimated torque value, an estimated stator flux linkage value, and a stator flux linkage angle of the permanent magnet synchronous electric spindle in a two-phase stationary coordinate system according to the stator three-phase voltage and the stator three-phase current specifically includes: obtaining the stator voltage and the stator current of the permanent magnet synchronous electric spindle under a two-phase static coordinate system according to the stator three-phase voltage and the stator three-phase current; obtaining a stator flux linkage component and a stator flux linkage estimated value of the permanent magnet synchronous electric spindle under the two-phase static coordinate system according to the stator voltage and the stator current; obtaining the stator flux linkage angle according to the stator flux linkage component; and obtaining the torque estimated value according to the stator flux linkage component and the stator current.

According to one embodiment of the invention, the stator voltage and the stator current of the permanent magnet synchronous electric spindle under the two-phase static coordinate system are obtained through Clark conversion, and the input quantity of the Clark conversion comprises the stator three-phase voltage and the stator three-phase current.

According to an embodiment of the present invention, deriving the adjustment signal from the torque deviation, the stator flux linkage deviation, and the stator flux linkage angle based on fuzzy control comprises: obtaining the direct axis stator voltage and the quadrature axis stator voltage of the permanent magnet synchronous electric spindle according to the torque deviation and the stator flux linkage deviation based on fuzzy control; obtaining a stator flux linkage angle mapping value of the permanent magnet synchronous electric spindle according to the stator flux linkage angle based on fuzzy control; obtaining the fuzzy stator voltage of the permanent magnet synchronous electric spindle under a two-phase static coordinate system according to the direct axis stator voltage, the quadrature axis stator voltage and the stator flux linkage angle mapping value; and obtaining an adjusting signal of the permanent magnet synchronous electric spindle according to the fuzzy stator voltage under the two-phase static coordinate system.

Further, fuzzification processing is carried out on the torque deviation and the stator flux linkage deviation by adopting a membership value method.

Further, the step of fuzzifying the stator flux linkage angle by adopting a membership value method comprises the following steps: setting a fuzzy domain change interval and a fuzzy subset of the stator flux linkage angle; dividing the fuzzy domain change interval of the stator flux linkage angle into a plurality of stator flux linkage sectors and marking the stator flux linkage sectors; and mapping any angle of the ambiguity domain change interval of the stator flux linkage angle into one of the plurality of stator flux linkage sectors by adopting a symmetry principle.

Further, the membership value method adopts a triangular membership function.

Further, the fuzzy stator voltage of the permanent magnet synchronous electric spindle under the two-phase static coordinate system is obtained through coordinate transformation, and input quantities of the coordinate transformation comprise the direct-axis stator voltage, the quadrature-axis stator voltage and the stator flux linkage angle mapping value.

Further, the adjusting signal of the permanent magnet synchronous electric spindle is obtained through SVPWM algorithm conversion, and the input quantity converted by the SVPWM algorithm comprises the fuzzy stator voltage under the two-phase static coordinate system.

Drawings

FIG. 1 is a flow chart of a method for adjusting speed of a permanent magnet synchronous electric spindle direct torque based on fuzzy control according to an embodiment of the present invention;

FIG. 2 is an algorithm diagram of a fuzzy control-based permanent magnet synchronous electric spindle direct torque speed regulation method according to an embodiment of the present invention;

FIG. 3 is a flow chart of calculating a torque estimate, a stator flux linkage estimate, and a stator flux linkage angle for a PMSM spindle according to one embodiment of the present invention;

FIG. 4 is a flow chart of obtaining an adjustment signal based on a torque offset, a stator flux linkage offset, and a stator flux linkage angle in accordance with an embodiment of the present invention;

FIG. 5 is a graph of membership functions for the input e, ec and output Δ kp, Δ ki variables of a fuzzy adaptive PID regulator in accordance with one embodiment of the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Fig. 1 is a flowchart of a method for adjusting speed of a permanent magnet synchronous electric spindle direct torque based on fuzzy control according to an embodiment of the present invention.

As shown in fig. 1, the method for adjusting speed of a permanent magnet synchronous electric spindle based on fuzzy control according to an embodiment of the present invention includes the following steps:

and S1, acquiring the actual rotating speed of the permanent magnet synchronous electric spindle.

Specifically, the actual rotation speed of the permanent magnet synchronous electric spindle can be obtained through a rotary transformer.

And S2, obtaining the actual torque of the permanent magnet synchronous electric main shaft according to the actual rotating speed and the set rotating speed of the permanent magnet synchronous electric main shaft.

Specifically, as shown in fig. 2, the actual rotation speed n of the permanent magnet synchronous electric spindle may be subtracted from the given rotation speed, and then the difference is input into the fuzzy adaptive PID regulator, so as to obtain the actual torque of the permanent magnet synchronous electric spindle

And S3, obtaining the stator three-phase voltage and the stator three-phase current of the permanent magnet synchronous electric spindle.

Specifically, as shown in fig. 2, the stator three-phase voltage and the stator three-phase current of the permanent magnet synchronous electric spindle may be obtained through a sensor disposed corresponding to the permanent magnet synchronous electric spindle three-phase circuit, wherein the stator three-phase voltage and the stator three-phase current may be respectively represented as u_a、u_b、u_cAnd i_a、i_b、i_c。

And S4, obtaining the torque estimation value, the stator flux linkage estimation value and the stator flux linkage angle of the permanent magnet synchronous electric main shaft according to the stator three-phase voltage and the stator three-phase current.

Specifically, the estimated torque value, the estimated stator flux linkage value and the stator flux linkage angle of the permanent magnet synchronous electric spindle in the two-phase stationary coordinate system can be obtained according to the three-phase voltage and the three-phase current of the stator, as shown in fig. 3, step S4 includes the following steps:

s401, obtaining stator voltage and stator current of the permanent magnet synchronous electric spindle in a two-phase static coordinate system according to the stator three-phase voltage and the stator three-phase current.

Specifically, as shown in FIG. 2, the stator three-phase voltages and the stator three-phase currents, i.e., u, may be divided_a、u_b、u_cAnd i_a、i_b、i_cAnd given stator flux linkage angle asObtaining the stator voltage and the stator current of the permanent magnet synchronous motor spindle under a two-phase static coordinate system, wherein the two-phase static coordinate system is α and β, and the stator voltage and the stator current of the permanent magnet synchronous motor spindle under the two-phase static coordinate system can be expressed as u_α、u_βAnd i_α、i_β。

The following voltage equation can be formed according to the stator voltage and the stator current of the permanent magnet synchronous electric spindle in the two-phase static coordinate system:

wherein R is stator resistance, omega_eIn order to determine the angular velocity of the rotor,is a permanent magnet flux linkage.

S402, obtaining stator flux linkage components and stator flux linkage estimated values of the permanent magnet synchronous electric spindle in the two-phase static coordinate system according to the stator voltage and the stator current.

Specifically, as shown in FIG. 2, the stator voltage and stator current, i.e., u, may be scaled_α、u_βAnd i_α、i_βRespectively inputting the magnetic flux components into a stator flux observer, and obtaining the stator flux component of the permanent magnet synchronous electric spindle under a two-phase static coordinate system, namely psi_α、Ψ_βAnd stator flux linkage estimates, i.e.

More specifically, the stator flux linkage component Ψ of the permanent magnet synchronous electric spindle in the two-phase stationary coordinate system can be calculated by the following formula_α、Ψ_β：

Wherein the content of the first and second substances,for the stator flux-linkage component Ψ_α，For the stator flux-linkage component Ψ_β。

And S403, obtaining a stator flux linkage angle according to the stator flux linkage component.

And S404, obtaining a torque estimated value according to the stator flux linkage component and the stator current.

Specifically, as shown in FIG. 2, the stator flux linkage component Ψ may be based on_α、Ψ_βAnd stator current i_α、i_βCarrying out torque estimation on the permanent magnet synchronous electric main shaft to finally obtain the torque estimation value T of the permanent magnet synchronous electric main shaft_e。

More specifically, the torque estimation value T of the permanent magnet synchronous electric spindle can be calculated by the following formula_e：

Wherein, P_nIs the pole pair number of the permanent magnet synchronous electric spindle.

And S5, acquiring the actual stator flux linkage of the permanent magnet synchronous electric spindle.

And S6, obtaining the torque deviation according to the actual torque and the torque estimated value, and obtaining the stator flux linkage deviation according to the actual stator flux linkage and the stator flux linkage estimated value.

Specifically, referring to FIG. 2, the actual torque may be comparedAnd an estimated torque value T_eInputting a torque fuzzy controller, obtaining the torque deviation of the permanent magnet synchronous electric main shaft through the torque fuzzy controller, and obtaining the actual stator flux linkage of the permanent magnet synchronous electric main shaftAnd stator flux linkage estimationAnd inputting the flux linkage fuzzy controller to obtain the torque deviation stator flux linkage deviation of the permanent magnet synchronous electric main shaft.

And S7, obtaining an adjusting signal according to the torque deviation, the stator flux linkage deviation and the stator flux linkage angle based on the fuzzy control so as to adjust the torque of the permanent magnet synchronous electric main shaft.

Specifically, as shown in fig. 4, step S7 includes the steps of:

and S701, obtaining the direct-axis stator voltage and the quadrature-axis stator voltage of the permanent magnet synchronous electric spindle according to the torque deviation and the stator flux linkage deviation based on fuzzy control.

Specifically, as shown in fig. 2, the torque deviation and the stator flux linkage deviation may be input as input quantities into the fuzzy controller, and finally the fuzzy controller may output a direct axis stator voltage and a quadrature axis stator voltage, i.e., u_d ^*And u_q ^*。

More specifically, the fuzzy controller may perform fuzzification processing on the torque deviation and the stator flux linkage deviation by using a membership value method, including setting a fuzzy domain change interval and a fuzzy subset for the torque deviation and the stator flux linkage deviation respectively. Wherein the fuzzy domain variation interval of the torque deviation can be set to be [ -2,2]Fuzzy subset { NB, NS, PS, PB }, and a transformation function of the torque deviation can be set asMeanwhile, the variation interval of the fuzzy domain of stator flux linkage deviation can be set to be [ -1,1 [ -1 [ ]]Fuzzy subset { NB, NS, PS, PB }, and can set a transformation function of stator flux linkage deviation asBy adopting the fuzzy controller to process the torque deviation and the stator flux linkage deviation, the hysteresis control precision and the robustness can be improved, the stator flux linkage and the torque pulsation can be reduced, and the reliability and the stability of the permanent magnet synchronous electric spindle can be improved.

S702, obtaining a stator flux linkage angle mapping value of the permanent magnet synchronous electric spindle according to the stator flux linkage angle based on fuzzy control.

Specifically, a membership value method can be adopted to perform fuzzification processing on the stator flux linkage angle, and the fuzzification processing specifically comprises the steps of setting a fuzzy domain change interval and a fuzzy subset of the stator flux linkage angle; dividing the fuzzy domain change interval of the stator flux linkage angle into a plurality of stator flux linkage sectors and marking the stator flux linkage sectors; and mapping any angle of the ambiguity domain change interval of the stator flux linkage angle into one of the plurality of stator flux linkage sectors by adopting a symmetry principle.

More specifically, the domain-fuzzy change interval of the stator flux linkage angle can be set to be [0, 2 pi ]]The fuzzy subset is { NB, NS, PS, PB }, and the transformation function of the stator flux linkage angle can be set asWherein, the fuzzy domain change interval [0, 2 pi ] of the stator flux linkage angle can be changed]Divided into six sectors, respectively labeled as first, second, third, fourth, fifth and sixth sectors, and further able to change the domain of ambiguity [0, 2 π ] according to the symmetry principle]Is mapped to the first sector, i.e.And (4) the following steps.

Wherein any angle of the universe of ambiguity change interval [0, 2 π ] can be mapped into the first sector by the following equation:

wherein int () is a floor function, θ is an estimated value of the stator flux angle, θ is^*The value of the stator flux linkage angle mapping value is in the range of

And S703, obtaining the fuzzy stator voltage of the permanent magnet synchronous electric spindle in the two-phase static coordinate system according to the direct-axis stator voltage, the quadrature-axis stator voltage and the stator flux linkage angle mapping value.

Specifically, as shown in FIG. 2, the direct axis stator voltage u_d ^*And quadrature axis stator voltage u_q ^*The fuzzy stator voltage of the permanent magnet synchronous electric spindle under the two-phase static coordinate system, namely u, can be obtained through second coordinate transformation_α ^*And u_β ^*。

And S704, obtaining an adjusting signal of the permanent magnet synchronous electric spindle according to the fuzzy stator voltage under the two-phase static coordinate system.

Specifically, as shown in fig. 2, the blurred stator voltage u in the two-phase stationary coordinate system may be adjusted_α ^*、u_β ^*And inputting the SVPWM into the SVPWM, and finally converting the SVPWM algorithm to obtain an adjusting signal of the permanent magnet synchronous electric spindle, wherein the adjusting signal can act on a power switching device of the inverter, for example, the optimal voltage vector can be selected through a switching state table to control the switching state of the inverter so as to realize the direct torque control of the permanent magnet synchronous electric spindle. The switching frequency of the inverter can be ensured to be constant through fuzzy control, and the dynamic response of the inverter switch is ensured to be faster, so that the stator flux linkage and the torque ripple can be reduced.

It should be noted that the fuzzy controller shown in fig. 2 includes fuzzy rules set for the torque deviation, the stator flux linkage deviation and the stator flux linkage angle, where the fuzzy rules may be set according to the expert experience of the direct torque speed regulation of the permanent magnet synchronous electric spindle.

In one embodiment of the present invention, the fuzzy domain change interval of the output variable of the fuzzy controller may be set to [1,6], and may be specifically represented as P1, P2, P3, P4, P5 and P6, where P1 represents decreasing the stator flux linkage and decreasing the torque, P2 represents decreasing the stator flux linkage and maintaining the torque, P3 represents decreasing the stator flux linkage and increasing the torque, P4 represents increasing the stator flux linkage and decreasing the torque, P5 represents increasing the stator flux linkage and maintaining the torque, and P6 represents increasing the stator flux linkage and increasing the torque, whereby 16 fuzzy rules shown in table 1 may be set.

TABLE 1

It should be noted that, in the fuzzy adaptive PID regulator shown in fig. 2, a corresponding fuzzy rule may also be set, and a membership value method may be adopted to perform a fuzzification process on the rotation speed deviation of the permanent magnet synchronous electric spindle according to the set fuzzy rule.

In an embodiment of the invention, the fuzzy self-adaptive PID regulator can obtain a corresponding instantaneous difference e and an instantaneous difference change ec according to an actual rotating speed and a set rotating speed of the permanent magnet synchronous electric spindle, and can perform fuzzy reasoning on the instantaneous difference e and the instantaneous difference change ec by adopting a set fuzzy rule to obtain an output variable, and finally can set the output variable by adopting a set fuzzy matrix rule.

Specifically, the fuzzy adaptive PID regulator can take an instantaneous difference e and an instantaneous difference change ec of the actual rotating speed and the set rotating speed of the permanent magnet synchronous electric spindle as input variables of the fuzzy adaptive PID regulator, and set the quantization level of the input variables to 7 levels, namely { -3, -2, -1,0,1,2,3}, wherein the domain-fuzzy change interval of the instantaneous difference e can be set to [ -10000,10000], and the domain-fuzzy change interval of the instantaneous difference change ec can be set to [ -150000,150000], and all obey a triangular membership function distribution curve; meanwhile, delta kp and delta ki can be set as output variables of the fuzzy self-adaptive PID regulator, and the quantization levels of the output variables delta kp and delta ki can be set to 7 levels, namely { -3, -2, -1,0,1,2,3}, wherein the domain-fuzzy change interval of the output variable delta kp can be set to [ -2,2], the domain-fuzzy change interval of the output variable delta ki can be set to [ -1,1], and the domain-fuzzy change intervals are all subject to a triangular membership function distribution curve; further, fuzzy subsets of the input variables e, ec and output variables Δ kp, Δ ki of the fuzzy adaptive PID regulator may each be set to { NB, NM, NS, Z, PS, PM, PB }.

In summary, a membership function plot of the input variables e, ec and the output variables Δ kp, Δ ki of the fuzzy adaptive PID regulator shown in fig. 5 and a membership function of the fuzzy subset of the input variables e, ec and the output variables Δ kp, Δ ki of the fuzzy adaptive PID regulator shown in table 2 can be obtained.

TABLE 2

Further, max-min of the Mamdani algorithm can be adopted to synthesize a fuzzy logic decision of the fuzzy self-adaptive PID regulator, the synthesized fuzzy logic decision is adopted to perform direct product calculation on fuzzy subsets of input variables e and ec of the fuzzy self-adaptive PID regulator, and then the direct product calculation result and a set fuzzy operator are adopted to perform fuzzy vector calculation, so that output variables delta kp and delta ki of the fuzzy self-adaptive PID regulator are obtained.

Further, the fuzzy matrix rule table can be queried to set the output variables Δ kp and Δ ki, wherein the output variable Δ kp can be set through the fuzzy matrix rule table shown in table 3, and the output variable Δ ki can be set through the fuzzy matrix rule table shown in table 4.

TABLE 3

TABLE 4

According to the method for directly regulating the torque of the permanent magnet synchronous electric main shaft based on the fuzzy control, firstly, the actual torque is obtained according to the actual rotating speed and the set rotating speed of the permanent magnet synchronous electric main shaft, secondly, the torque estimated value, the stator flux linkage estimated value and the stator flux linkage angle of the permanent magnet synchronous electric main shaft are obtained according to the stator three-phase voltage and the three-phase current of the permanent magnet synchronous electric main shaft, secondly, the torque deviation is obtained according to the actual torque and the torque estimated value, the stator flux linkage deviation is obtained according to the actual stator flux linkage and the stator flux linkage estimated value, and finally, the regulating signal is obtained according to the torque deviation, the stator flux linkage deviation and the stator flux linkage angle based on the fuzzy control so as to regulate the torque of the permanent magnet synchronous electric main shaft, therefore, the pulsation of the stator flux linkage and the torque of the permanent magnet synchronous electric main shaft can be, therefore, the precision of numerical control machining based on the permanent magnet synchronous electric spindle can be ensured.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.