Numerical control machine tool state determination system using reconstructed current and determination method thereof

Abstract

The application relates to a numerical control machine tool state judgment system and method using reconstructed current, and the numerical control machine tool state judgment system using reconstructed current comprises an active current system and a reconstructed current system. The active current system comprises a strong current output unit and a weak current output unit, and the reconstructed current system comprises a bus sampling unit, a strong current reconstruction unit, a weak current reconstruction unit and a current comparison unit. Based on the numerical control machine tool state judgment system using reconstructed current, according to the active output of the active current system, the reconstructed current system carries out electric signal sampling to realize calibration, judges the working states of the strong current electric control module and the weak current electric control module of the numerical control machine tool, and automatically detects each electric control module of each numerical control machine tool in time and comprehensively, so as to guarantee the stable operation of the numerical control machine tool.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent machine tools, in particular to a numerical control machine tool state determination system using reconstructed current and a determination method thereof. BACKGROUND

[0002] A numerical control machine tool is a short form of Computer numerical control machine tools, which is an automatic machine tool equipped with a program control system. The control system can logically process programs with control codes or other symbolic instructions and translate them into code numbers, which are input into the numerical control device through information carriers. After operation and processing, the numerical control device sends various control signals to control the machine tool, automatically processes parts according to the shape and size required by the drawing. As can be seen, the numerical control machine tool is a mechatronics product integrating mechanical, electrical, hydraulic, pneumatic, microelectronic and information technologies.

[0003] It can be seen that the numerical control machine tool involves electrical, microelectronic and information control modules, and its working state is closely related to the electrical control module. In actual application, the working state of the numerical control machine tool is determined by collecting electrical signals of the electrical control module. However, since the electrical control module of the numerical control machine tool involves strong and weak electricity, and the number of modules is complex, the test method is relatively complex, and engineers generally only test the key electrical control module, so that the abnormality of other electrical control modules is not easy to be found, which affects the accuracy of the working state determination of the numerical control machine tool. SUMMARY

[0004] According to the above analysis, in order to solve the problem that the electrical control module of the numerical control machine tool involves strong and weak electricity, and the number of modules is complex, the test method is relatively complex, and engineers generally only test the key electrical control module, so that the abnormality of other electrical control modules is not easy to be found, which affects the accuracy of the working state determination of the numerical control machine tool, the present application provides a numerical control machine tool state determination system using reconstructed current and a determination method thereof.

[0005] The present application provides a numerical control machine tool state determination system using reconstructed current.

[0006] A numerical control machine tool state determination system using reconstructed current comprises:

[0007] An active current system and a reconstructed current system;

[0008] The active current system comprises a strong current output unit and a weak current output unit;

[0009] The strong current output unit is configured to output a first current to a strong current electrical control module in the numerical control machine tool;

[0010] The weak current output unit is configured to output a second current to a weak current control module in the numerical control machine tool;

[0011] The reconstructed current system comprises a bus sampling unit, a strong current reconstruction unit, a weak current reconstruction unit and a current comparison unit.

[0012] The bus sampling unit is configured to sample an electrical signal of the strong current control module to obtain a third current, and sample an electrical signal of the weak current control module to obtain a fourth current.

[0013] The strong current reconstruction unit is configured to reconstruct a first calibration current according to the third current.

[0014] The weak current reconstruction unit is configured to reconstruct a second calibration current according to the fourth current.

[0015] The current comparison unit is configured to compare the first calibration current and output a first state determination result of the strong current control module according to a comparison result, and compare the second calibration current and output a second state determination result of the weak current control module according to a comparison result.

[0016] The numerical control machine tool state determination system using reconstructed current comprises an active current system and a reconstructed current system. The active current system comprises a strong current output unit and a weak current output unit, and the reconstructed current system comprises a bus sampling unit, a strong current reconstruction unit, a weak current reconstruction unit and a current comparison unit. According to the active output of the active current system, the bus sampling unit samples an electrical signal to realize calibration, and determines the working state of the strong current control module and the weak current control module of the numerical control machine tool, so as to automatically detect each control module of each numerical control machine tool in time and comprehensively, and ensure the stable operation of the numerical control machine tool.

[0017] In one embodiment, the active current system is based on a PWM controller.

[0018] In one embodiment, the bus sampling unit comprises:

[0019] a sampling bus;

[0020] a two-input switch circuit, one output end of which is connected to the sampling bus, and two input ends of which are connected to the strong current control module and the weak current control module respectively.

[0021] In one embodiment, the strong current reconstruction unit, the weak current reconstruction unit and the current comparison unit are based on the same processor.

[0022] A determination method of a numerical control machine tool state determination system using reconstructed current comprises the following steps:

[0023] inserting a first sampling sequence at the beginning of each section of the first reference current to form the first current;

[0024] inserting a plurality of second sampling sequences at the set window of the second reference current to form the second current; wherein the sampling sequences are related to the fourth current;

[0025] sequentially sampling the first sampling sequence to form the third current;

[0026] sampling the first sampling sequence to form the third current; and sampling the second sampling sequence to form the fourth current;

[0027] reconstructing the third current according to the first sampling sequence at the insertion timing of the first reference current to obtain a first calibration current;

[0028] reconstructing the fourth current according to the second sampling sequence at the insertion timing of the second reference current to obtain a second calibration current;

[0029] when the difference between the first calibration current and a first set current is less than a first difference, determining that the working state of the strong-current electric control module is normal, otherwise, determining that the working state of the strong-current electric control module is abnormal;

[0030] when the difference between the second calibration current and a second set current is less than a second difference, determining that the working state of the weak-current electric control module is normal, otherwise, determining that the working state of the weak-current electric control module is abnormal.

[0031] The above-mentioned determination method of the numerical control machine tool state determination system using reconstructed currents is based on the numerical control machine tool state determination system using reconstructed currents, and according to the active output of the active current system, the electric signal sampling is performed by the reconstructed current system to realize calibration, determine the working state of the strong-current electric control module and the weak-current electric control module of the numerical control machine tool, and automatically detect each electric control module of each numerical control machine tool in time and comprehensively, so as to ensure the stable operation of the numerical control machine tool.

[0032] In one embodiment, the process of inserting a first sampling sequence at the beginning of each section of the first reference current to form the first current includes the following steps:

[0033] inserting two effective vectors at the beginning of each section of the first reference current to form the first current.

[0034] In one embodiment, the process of inserting a plurality of second sampling sequences at the set window of the second reference current to form the second current includes the following steps:

[0035] inserting two second sampling sequences at adjacent wave bands of the second reference current respectively to form the second current.

[0036] In one of the embodiments, the process of reconstructing the third current according to the first sampling sequence at the insertion timing of the first reference current to obtain the first calibration current comprises the steps of:

[0037] reconstructing the first two phases of the first calibration current according to two continuous first sampling sequences;

[0038] calculating the third phase of the first calibration current according to the first two phases of the first calibration current.

[0039] In one of the embodiments, the process of reconstructing the fourth current according to the second sampling sequence at the insertion timing of the second reference current to obtain the second calibration current comprises the steps of:

[0040] reconstructing the first two phases of the second calibration current according to two continuous second sampling sequences;

[0041] calculating the third phase of the second calibration current according to the first two phases of the second calibration current.

[0042] In one of the embodiments, the process further comprises the steps of:

[0043] performing Clark transformation on the second calibration current to obtain a first intermediate current value;

[0044] performing PARK transformation on the first intermediate current value to obtain a second intermediate current value

[0045] performing inverse PARK transformation and inverse Clark transformation according to the angle step of the PARK transformation and the second intermediate current value to obtain the predicted value of the next carrier cycle of the second calibration current. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 a module structure diagram of the state determination system of the numerical control machine tool using the reconstructed current according to one of the embodiments;

[0047] Figure 2 a flow chart of the determination method of the state determination system of the numerical control machine tool using the reconstructed current according to one of the embodiments;

[0048] Figure 3 a flow chart of the determination method of the state determination system of the numerical control machine tool using the reconstructed current according to the preferred embodiment;

[0049] Figure 4 a timing diagram of the second calibration current. DETAILED DESCRIPTION

[0050] In order to better understand the purposes, technical solutions and technical effects of the present application, the present application is further explained below in combination with the drawings and examples. Meanwhile, it is declared that the following described examples are only for explaining the present application, and are not for limiting the present application.

[0051] The embodiment of the present application provides a numerical control machine tool state determination system using reconstructed current.

[0052] Figure 1 A module structure diagram of the numerical control machine tool state determination system using reconstructed current of an embodiment is shown in the figure, and the numerical control machine tool state determination system using reconstructed current of an embodiment comprises: Figure 1

[0053] An active current system 10 and a reconstructed current system 11;

[0054] The active current system 10 comprises a strong current output unit 100 and a weak current output unit 101;

[0055] The strong current output unit 100 is used for outputting a first current I1 to a strong current electric control module 200 in a numerical control machine tool;

[0056] The weak current output unit 101 is used for outputting a second current I2 to a weak current electric control module 201 in the numerical control machine tool;

[0057] The reconstructed current system 11 comprises a busbar sampling unit 110, a strong current reconstruction unit 111, a weak current reconstruction unit 112 and a current comparison unit 113;

[0058] The busbar sampling unit 110 is used for sampling an electric signal of the strong current electric control module 200 to obtain a third current I3, and is also used for sampling an electric signal of the weak current electric control module 201 to obtain a fourth current I4;

[0059] The strong current reconstruction unit 111 is used for reconstructing a first calibration current I REF1 according to the third current I3;

[0060] The weak current reconstruction unit 112 is used for reconstructing a second calibration current I REF2 according to the fourth current I4;

[0061] The current comparison unit 113 is used for comparing the first calibration current I REF1, and outputting a first state determination result of the strong current electric control module 200 according to a comparison result; and is also used for comparing the second calibration current I REF2, and outputting a second state determination result of the weak current electric control module 201 according to a comparison result.

[0062] ​In the embodiment, the objects of state determination of the numerical control machine tool are the strong electric control module and the weak electric control module of the numerical control machine tool. According to the use area, the strong electric control module and the weak electric control module can be distinguished in advance, and the strong electric output unit and the weak electric output unit are correspondingly allocated. The premise of state determination of the strong electric control module and the weak electric control module is that both are in the power-off state, and the strong electric output unit and the weak electric output unit are powered on to provide a basis for the subsequent bus sampling unit.

[0063] For cost considerations, the electric signal sampling of the strong electric output unit and the weak electric output unit is performed through the single bus sampling design of the bus sampling unit. Meanwhile, in terms of wiring and module deployment, the influence on the structure of the original numerical control machine tool and the electric signal interference are reduced to avoid affecting the machining precision of the original numerical control machine tool.

[0064] In one of the embodiments, the active current system is built based on the PWM controller. The output of the strong electric output unit and the weak electric output unit is based on the modulation ratio of the PWM controller. The output higher than the set modulation ratio is the output of the weak electric output unit, and the output lower than the set modulation ratio is the output of the strong electric output unit. The set modulation ratio can be set by relevant personnel according to the equipment type of the numerical control machine tool, which is not limited herein.

[0065] In one of the embodiments, the bus sampling unit comprises:

[0066] a sampling bus;

[0067] a two-way switch circuit, one output end of which is connected to the sampling bus, and two input ends of which are respectively connected to the strong electric control module and the weak electric control module.

[0068] Through the two-way switch circuit, the single bus sampling design is realized. The two-way switch circuit can be a controllable switch device such as a relay or a switch chip.

[0069] Based on the numerical control machine tool state determination system using reconstructed current of one embodiment, the embodiment further provides a determination method of the numerical control machine tool state determination system using reconstructed current. Figure 2 The flow chart of the determination method of the numerical control machine tool state determination system using reconstructed current of one embodiment is shown in Figure 2 The flow chart of the determination method of the numerical control machine tool state determination system using reconstructed current of one embodiment is shown in

[0070] S10, a first sampling sequence is inserted at the beginning of each first reference current segment to form the first current;

[0071] S11, a plurality of second sampling sequences are inserted in the set window of the second reference current to form the second current; wherein the sampling sequence is related to the fourth current;

[0072] S12, sequentially sampling the first sampling sequence to form a third current;

[0073] S13, sampling the first sampling sequence to form a third current; meanwhile, sampling the second sampling sequence to form a fourth current;

[0074] S14, reconstructing the third current according to the first sampling sequence at the insertion timing of the first reference current to obtain a first calibration current;

[0075] S15, reconstructing the fourth current according to the second sampling sequence at the insertion timing of the second reference current to obtain a second calibration current;

[0076] S16, when the difference between the first calibration current and a first set current is less than a first difference, determining that the working state of the strong electric control module is normal, otherwise, determining that the working state of the strong electric control module is abnormal;

[0077] S17, when the difference between the second calibration current and a second set current is less than a second difference, determining that the working state of the weak electric control module is normal, otherwise, determining that the working state of the weak electric control module is abnormal.

[0078] The PWM controller adopts multi-segment wave emission, and outputs in the form of multiple sectors, each sector corresponds to a segment of the first reference current, and the first sampling sequence is inserted at the beginning of each segment of the first reference current, and the first reference current is updated to form the first current.

[0079] Similarly, based on the multi-segment wave emission of the PWM controller, the second reference current includes multiple sectors in the form of multiple sectors. According to the selection of the sector, a set window is determined, and multiple second sampling sequences are inserted to form the second current.

[0080] In one preferred embodiment, Figure 3 The flow chart of the determination method of the numerical control machine tool state determination system using the reconstructed current for the preferred embodiment is shown in Figure 3 As shown in step S10, the process of inserting the first sampling sequence at the beginning of each segment of the first reference current to form the first current includes step S20:

[0081] S20, inserting two effective vectors at the beginning of each segment of the first reference current to form the first current.

[0082] After the effective vector is inserted, the null vector and the effective vector are included in the starting section of the first reference current, at this time, in order to ensure that the null vector is greater than zero, the basis is that the modulation ratio of the PWM controller is lower than the set modulation ratio, otherwise the null vector is less than zero, then the insertion of the effective vector does not work. The insertion of the effective vector can change the center symmetry of the first reference current, so that the characteristics of the bus output after the first reference current passes through the strong electric control module are obvious, if the working state of the strong electric control module is normal, then the characteristics can be captured in the third current to reconstruct the first calibration current.

[0083] However, when the modulation ratio of the PWM controller is greater than the set modulation ratio, it is applicable to the weak electric control module but the corresponding null vector is less than 0, so the sampling sequence insertion cannot be performed in the starting section. Preferably, as shown in Figure 3 the process of inserting a plurality of second sampling sequences in the set window of the second reference current in step S11 to form the second current includes steps S21 and S22:

[0084] S21, two second sampling sequences are respectively inserted in adjacent wave sections of the second reference current to form the second current.

[0085] Based on this, as shown in Figure 3 the process of reconstructing the third current according to the insertion timing of the first sampling sequence in the first reference current to obtain the first calibration current in step S14 includes steps S22 and S23:

[0086] S22, the first two phases of the first calibration current are reconstructed according to two continuous first sampling sequences.

[0087] S23, the third phase of the first calibration current is calculated according to the first two phases of the first calibration current.

[0088] The process of reconstructing the fourth current according to the insertion timing of the second sampling sequence in the second reference current to obtain the second calibration current in step S15 includes steps S24 and S25:

[0089] S24, the first two phases of the second calibration current are reconstructed according to two continuous second sampling sequences.

[0090] S25, the third phase of the second calibration current is calculated according to the first two phases of the second calibration current.

[0091] In steps S22 and S23, the first first sampling sequence completes sampling of the U-phase current Iu, and the second first sampling sequence completes sampling of the W-phase current Iw; the V-phase current Iv=-Iu-Iw is calculated, and the others are calculated in the same way. The first calibration current includes three-phase currents of U-phase, W-phase and V-phase.

[0092] In step S24 and step S25, as shown in the second calibration current timing diagram of the application, Figure 4 When the high modulation interval is large enough, most of the time the second sampling sequence T1, T2 is large enough, in T1 segment, the U-phase current Iu is sampled, as shown in Figure 4 ADC1; in T2 segment, the W-phase current Iw is sampled, as shown in Figure 4 ADC2; Iv=0-Iu-Iw is calculated. The second calibration current is the three-phase current including U-phase, W-phase and V-phase.

[0093] But there is an exception in step S24 and step S25, when the sector switching point θ is close to 0 or The second sampling sequence T1, T2 is still small, at this time, the sampling window is narrow, and the three-phase current cannot be reconstructed. In this preferred embodiment, as shown in Figure 3 It also includes steps S26, S27 and S28:

[0094] S26, Clark transformation is performed on the second calibration current to obtain the first intermediate current value;

[0095] S27, PARK transformation is performed on the first intermediate current value to obtain the second intermediate current value

[0096] S28, according to the angle step size of the PARK transformation and the second intermediate current value, inverse PARK transformation and inverse Clark transformation are performed in turn to obtain the predicted value of the next carrier period of the second calibration current.

[0097] On the basis of the second calibration current Iu, Iw and Iv, the Clark transformation is performed on the current to obtain the first intermediate current value i α , i β , and then the PARK transformation is performed to obtain the second intermediate current value i d , i q . The angle θ1 when performing the PARK transformation is the integral of the output frequency during VF operation, and then the angle step size Δθ is calculated according to the current output frequency and the period of the PWM controller, and the frequency integral θ2=θ1+Δθ of the next PWM carrier is calculated. According to the current i d , i q and θ2, the inverse PARK transformation is performed to obtain i α1 , i β1 ; and then the inverse Clark transformation is performed to obtain the current prediction value I u1 , I v1 , I w1 . In the next PWM period, if one of T1, T2 calculated is less than the minimum sampling window T minWhen one phase current cannot be reconstructed, the current prediction value calculated by the previous PWM is assigned to the current sampling value.

[0098] At this time, the first calibration current and the second calibration current reconstructed both have obvious characteristics, matching the working state of the corresponding strong current electric control module and weak current electric control module. The current comparison unit compares the first calibration current, and outputs the first state determination result of the strong current electric control module according to the comparison result, compares the second calibration current, and outputs the second state determination result of the weak current electric control module according to the comparison result. The working state of the strong current electric control module and the weak current electric control module can be determined by comparing the current size of the first calibration current and the second calibration current. The comparison standard of the current comparison unit is determined according to the experimental experience.

[0099] The numerical control machine tool state determination system and the determination method thereof using reconstructed current of the embodiment, the numerical control machine tool state determination system using reconstructed current, including an active current system and a reconstructed current system. The active current system includes a strong current output unit and a weak current output unit, and the reconstructed current system includes a bus sampling unit, a strong current reconstruction unit, a weak current reconstruction unit and a current comparison unit. Based on the numerical control machine tool state determination system using reconstructed current, according to the active output of the active current system, the reconstructed current system samples the electric signal to realize calibration, determines the working state of the strong current electric control module and the weak current electric control module of the numerical control machine tool, and automatically detects each electric control module of each numerical control machine tool in time and comprehensively, so as to ensure the stable operation of the numerical control machine tool.

[0100] The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

Claims

1. A numerical control machine tool state determination system using a reconstructed current, characterized by, The application relates to a current system for a numerical control machine tool, comprising: an active current system and a reconstructed current system; wherein the active current system comprises a strong current output unit and a weak current output unit; the strong current output unit is used for outputting a first current to a strong current electric control module in the numerical control machine tool; the weak current output unit is used for outputting a second current to a weak current electric control module in the numerical control machine tool; the reconstructed current system comprises a bus sampling unit, a strong current reconstruction unit, a weak current reconstruction unit and a current comparison unit; the bus sampling unit is used for sampling an electric signal of the strong current electric control module to obtain a third current, and sampling an electric signal of the weak current electric control module to obtain a fourth current; the bus sampling unit comprises: a sampling bus; a two-alternative switch circuit, one output end of which is connected with the sampling bus, and two input ends of which are connected with the strong current electric control module and the weak current electric control module respectively; a sampling circuit, which samples an electric signal of the sampling bus to obtain the third current or the fourth current; the strong current reconstruction unit is used for reconstructing a first calibration current according to the third current, and comprises the following steps: reconstructing the third current according to a first sampling sequence at an insertion timing of a first reference current to obtain the first calibration current; reconstructing the first two phases of the first calibration current according to two continuous first sampling sequences; calculating the third phase of the first calibration current according to the first two phases of the first calibration current; the weak current reconstruction unit is used for reconstructing a second calibration current according to the fourth current, and comprises the following steps: reconstructing the fourth current according to a second sampling sequence at an insertion timing of a second reference current to obtain the second calibration current; reconstructing the first two phases of the second calibration current according to two continuous second sampling sequences; calculating the third phase of the second calibration current according to the first two phases of the second calibration current; the current comparison unit is used for comparing the first calibration current and outputting a first state judgment result of the strong current electric control module according to a comparison result, and is also used for comparing the second calibration current and outputting a second state judgment result of the weak current electric control module according to a comparison result.

2. The numerical control machine tool state determination system using a reconstructed current according to claim 1, characterized by, The active current system is built based on a PWM controller.

3. The numerical control machine tool state determination system using a reconstructed current according to claim 1, characterized by, The strong current reconstruction unit, the weak current reconstruction unit and the current comparison unit are built based on the same processor.

4. A determination method of a state determination system of a numerical control machine tool using a reconstructed current, characterized by, The method comprises the following steps: inserting a first sampling sequence at the beginning of each first reference current to form a first current; inserting a plurality of second sampling sequences at a set window of a second reference current to form a second current; wherein the sampling sequence is related to the fourth current; sampling the current in the first sampling sequence in sequence to form the third current; sampling the current in the first sampling sequence to form the third current, and sampling the current in the second sampling sequence to form the fourth current; reconstructing the third current according to the first sampling sequence at the insertion timing of the first reference current to obtain the first calibration current; reconstructing the fourth current according to the second sampling sequence at the insertion timing of the second reference current to obtain the second calibration current; When the difference between the first calibration current and the first set current is less than the first difference, the working state of the strong electric control module is determined to be normal, otherwise, to be abnormal; When the difference between the second calibration current and the second set current is less than the second difference, the working state of the weak electric control module is determined to be normal, otherwise, to be abnormal.

5. The determination method of the numerical control machine tool state determination system using the reconstructed current according to claim 4, characterized in that, The process of inserting the first sampling sequence at the beginning of each segment of the first reference current to form the first current comprises the steps of: Two effective vectors are inserted at the beginning of each segment of the first reference current to form the first current.

6. The determination method of the numerical control machine tool state determination system using the reconstructed current according to claim 4, characterized in that, The process of inserting a plurality of second sampling sequences at the set window of the second reference current to form the second current comprises the steps of: Two second sampling sequences are inserted at adjacent wave segments of the second reference current to form the second current.

7. The determination method of the numerical control machine tool state determination system using the reconstructed current according to claim 4, characterized in that, The process of reconstructing the third current according to the insertion timing of the first sampling sequence at the first reference current to obtain the first calibration current comprises the steps of: According to two continuous first sampling sequences, the first two phases of the first calibration current are reconstructed; According to the first two phases of the first calibration current, the third phase of the first calibration current is calculated.

8. The determination method of the numerical control machine tool state determination system using the reconstructed current according to claim 4, characterized in that, The process of reconstructing the fourth current according to the insertion timing of the second sampling sequence at the second reference current to obtain the second calibration current comprises the steps of: According to two continuous second sampling sequences, the first two phases of the second calibration current are reconstructed; According to the first two phases of the second calibration current, the third phase of the second calibration current is calculated.

9. The determination method of the numerical control machine tool state determination system using the reconstructed current according to claim 8, characterized in that, The process further comprises the steps of: The second calibration current is subjected to Clark transformation to obtain a first intermediate current value; The first intermediate current value is subjected to PARK transformation to obtain a second intermediate current value; According to the angle step of the PARK transformation and the second intermediate current value, inverse PARK transformation and inverse Clark transformation are sequentially performed to obtain the predicted value of the next carrier cycle of the second calibration current.

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