KR20190013344A - An Intelligent CNC machine control system for smart monitering, smart diagnosis and smart control by using the physical cutting characteristic map in which the cutting characteristics are mapped in accordance to cutting location in terms of cutting time on working coordinate - Google Patents

Abstract

The present invention relates to an intelligent computer numerical control (CNC) machine tool control system capable of intelligently monitoring and diagnosing a cutting state, and controlling a cutting condition and, more specifically, to an intelligent CNC machine tool control system capable of performing a cutting state monitoring function, a diagnosis function for defect in the cutting state, and changing a poor and low-productive cutting condition into a high quality and high productive cutting condition to control the cutting condition when performing cutting. In particular, the intelligent CNC machine tool control system uses a cutting characteristic map mapping a processing position and a corresponding physical result value including processing vibration and sound in a CNC virtual coordinate system in accordance with a processing time in order to intelligently monitor and diagnose the cutting state, and change and control the cutting condition. To this end, the control system comprises: a sync mapping module mapping the characteristic value of a physical situation to processing information arranged in an advancing sequence; a diagnosis module comparing the mapped physical characteristic value received through the sync mapping module with a previously stored processing NC code to perform intelligent diagnosis through a diagnosis logic related to processing quality and processing productivity; and a control module performing control for changing the processing condition in accordance with a diagnosis result of the diagnosis module.

Description

An intelligent CNC machine tool control system capable of intelligently monitoring and diagnosing cutting conditions and controlling cutting conditions using a cutting characteristic map that maps machining positions and physical machining characteristic values according to machining time on a machining coordinate system {An Intelligent CNC machine control system for smart monitering, smart diagnosis and smart control by using the cutting characteristic of the cutting edge,

The present invention relates to an intelligent CNC machine tool control system capable of intelligently monitoring and diagnosing cutting conditions and controlling cutting conditions. More particularly, the present invention relates to a CNC machine tool control system, The present invention relates to an intelligent CNC machine tool system capable of performing a function to change and control defective and low productivity cutting conditions to high quality and high productivity cutting conditions.

In particular, the above-mentioned intelligent monitoring, diagnosis, and control of change of cutting conditions are performed by using a cutting characteristic map in which the physical characteristic values of sensors such as machining vibration and machining noise are mapped on the CNC machined coordinate system according to the machining time The present invention relates to an intelligent CNC machine tool system capable of performing the above-

In general, machining operations such as milling, raising, drilling, and boring are performed in a machining center, which is a single integrated machine that can be performed in a dedicated machine tool or in a variety of cutting processes. In recent years, the use of machining centers, which are favorable for machining small-quantity parts in a variety of different types, is increasing. In addition, CNC machine tools in machining centers are machined to CNC (Computer Numerical Controller) This is possible.

Such a CNC machine tool is a NC (Numerical Control) machine tool incorporating a high-performance computing device. The CNC machine tool automatically converts the machining shape, machining conditions, and machining operation data into NC data, And drives the machine tool in the signaled state.

As described above, the CNC machine tool is advantageous in that it has high machining precision and can perform various types of cutting operations. On the other hand, there are the following problems. Specifically, the chatter vibration generated during machining causes the tool to shake, There is a problem related to CNC cutting processing such as generation of defects, overload due to tool wear, and breakage of tools.

In order to solve the above problems, there is a registered technology 10-0724809 (registered on May 28, 2007, hereinafter referred to as "Prior Art 1"). To the CNC cutting process. That is, the prior art 1 relates to a 'method of processing a material in a CNC machine tool', in particular, a weight compensation function is applied to a CNC machine tool to automatically detect a change in weight of a workpiece By automatically optimizing the CNC Servo System and machining parameters, it is possible to maintain the stability of the servo system by eliminating the cumbersome operation of the user due to the weight change of the material.

However, the above-mentioned prior art 1 optimizes the processing parameters according to the weight change of the object to be processed. Since only the weight change of the object is used under the optimizing conditions of the processing parameters, There is a limit.

[0004] The prior art 2 relates to an intelligent CNC machine tool having an automatic machining function and a control method thereof. [0005] , The operating state of the CNC machine tool is measured by a sensor, the measurement value is compared with the reference value of the reference DB to diagnose the goodness of the cutting operation of the CNC machine tool, and the processing variable is controlled to the value of the reference DB Processing technology.

In the prior art 2, after a shape model, a material, a tool, and the like to be used for machining are determined, machining is performed by selecting an appropriate machining condition in the reference DB, and in particular, axial displacement and angular displacement according to the spindle rotation speed A spindle of the machine tool, a speed sensor attached to the transfer part, a thermal sensor, etc. for detecting a machining position error due to thermal deformation or the like occurring in the transfer part of the machining table, and the measured value is compared with the value of the reference DB And the machine tool maintains the optimum machining state.

However, the above-mentioned prior art 2 is limited to utilizing the changing characteristic of the machine tool due to axial displacement, thermal deformation, and the like, which occurs in the driving and feeding part of the machine tool. There has been a limit in improving machining errors due to chatter vibration caused by abrasion or the like. In addition, CNC machine tools having the same physical characteristics and conditions for performing monitoring, diagnosis, and control based on the reference DB based on ideal condition values of the CNC machine tools are realistically unique, It is difficult to build a standard DB.

[0002] Recently, a registered trademark 10-1501409 (Registered as "Prior Art 3") refers to an apparatus for monitoring a machining state of a machine tool, and includes a main shaft of a machine tool, A calculation output unit for outputting the rotation accuracy of the spindle by measuring a displacement value between the spindle and the workpiece through the same measuring means, and a photographing means for photographing the state of the workpiece in real time, Based on this, it is possible to find the processing parameters influencing the state of the workpiece and the tool and to obtain the optimum processing conditions.

However, since the above-mentioned conventional nose 3 can grasp the machining state only by the distance displacement value between the spindle and the workpiece and the image of the workpiece state image by the measurement means provided on the main shaft and chuck, accurate machining error can not be monitored and diagnosed, There is a problem that the improvement of the condition can not be achieved.

0001. Registration No. 10-0724809 (registered on May 28, 2007) 0002. Registration No. 10-1257275 (April 15, 2013, registered) 0003. Registration No. 10-1501409 (Registered on April 03, 2015)

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the above-described problems, and it is an object of the present invention to provide a cutting machining map by mapping machining-related physical property values corresponding to a machining position and a machining time on a machining coordinate system, And to provide an intelligent CNC machine tool control system for controlling the cutting conditions by utilizing the CNC machine tool control system.

At this time, the present invention synchronizes the machining position according to the machining time, and detects and diagnoses the defective factors such as the tool shaking and the machining overload which occur during cutting, and then controls the cutting condition so as to stably and high- An object of the present invention is to provide an intelligent CNC machine tool control system that improves productivity by upwardly controlling cutting conditions that are machining but have a low machining speed.

According to an aspect of the present invention, there is provided a method of processing a physical object, the method comprising: a synchronization mapping module for mapping a characteristic value of a physical situation to be processed in accordance with a machining time and a machining order; A diagnostic module for performing intellectual diagnosis through processing logic related to machining quality and machining productivity by concurrently using machining NC codes generated by existing commercially available CAM software or the like and control for changing machining conditions according to the diagnosis result of the diagnosis module And a control module for controlling the display device.

The diagnostic module may include a diagnostic information monitoring submodule for displaying the diagnosed information on a screen and a precision diagnostic logic submodule for precisely diagnosing the processing state.

In addition, the plurality of sensors may include an acoustic sensor for collecting a machining noise (sound) generated when the machining tool cuts off, a current sensor for measuring a machining load to which the machining tool is transmitted to the main axis at the time of cutting, At least one of an accelerometer sensor for measuring, an IR sensor and an infrared image sensor for measuring heat generated between the processing tool and the workpiece, and a spindle processing load sensor for measuring the processing load of the spindle motor built in the CNC machine tool .

Further, the diagnostic module may use the information transmitted through the synchronization mapping module and the machining NC code in parallel to calculate a machining load pattern mathematically predicted through the machining NC code, from the physical characteristic values transmitted through the synchronization mapping module It is used as intelligent diagnosis logic through pattern analysis by processing position and processing time of machining tool.

For example, the degree of wear of the machining tool and the possibility of breakage of the machining tool are diagnosed, or a pattern in which the machining load continuously increases during machining of the machining tool is displayed, and the machining load is close to "0" In the case where a sudden pattern appears, it is diagnosed that the cutting tool can not be practically broken due to the breakage of the cutting tool, or the inherent vibration characteristic of each blade of the cutting tool is analyzed through the FFT analysis. If the magnitude of the vibration is large compared to the magnitude of vibration generated by normal machining (close to '0' or at least twice the magnitude of the normal machining vibration) Or FFT analysis of the vibration generated during cutting of the small diameter tool and FFT analysis of the vibration of the main axis spindle motor are carried out, After eliminating the overlap between the excitation frequency and the harmonic frequency of the dog vibration and obtaining only the frequencies due to the cutting vibration of the small tool, the magnitude of the frequency due to the cutting vibration of the small tool is made larger than the excitation frequency of the main axis spindle motor And a pattern of the first to sixth frequencies is analyzed in terms of the pattern and size to diagnose whether or not the small-diameter tool is damaged.

In addition, when the defective machining conditions are changed and controlled to high-quality machining conditions after the diagnosis, or when the productivity is low even though the machining conditions are good, high-quality machining can be performed with high productivity by controlling the feed rate and the RPM of the spindle. So as to be controlled.

According to the present invention as described above, while the CNC machine tool is being machined, the machining position corresponding to the machining time and the physical characteristic value generated at each position are grasped and diagnosed, And the like can be improved.

In addition, it is possible to reduce machining defects caused by excessive machining load and chatter vibration occurring during machining of CNC machine tools, improve the quality of cutting machining, and intelligently control machining to perform high quality machining with high productivity. It is advantageous to develop various application work tools such as application that can be performed.

Further, the present invention is characterized in that when correcting the NC machining data by using the data of the above-described diagnosis result and the physical property value, the machining position corresponding to the machining position, and the machining time, And the cutting condition is corrected on the basis of the physical principle. Therefore, the modified NC machining data which can perform the high quality machining and the high productivity machining compared with the existing NC machining data before the modification can be easily And by using it, it is possible to develop a cutting processing control application for improving the processing quality and processing productivity.

Further, the present invention can also be utilized for developing an intelligent machine tool and an open controller for performing intelligent machining by applying the intelligent monitoring, intelligent diagnosis, intelligent control function and implementation technology to a CNC machine tool.

1 is a schematic view showing an intelligent CNC machine tool control system according to the present invention.
2 is a flow chart schematically illustrating an operation state of an intelligent CNC machine tool control system according to the present invention.
FIG. 3 is a diagram showing an example in which the shaking of a cutting tool diagnosed through the fine diagnosis logic submodule according to the present invention is diagnosed through FFT analysis, and then the rotation speed of the spindle is changed to control the shaking of the cutting tool.
Figure 4 is an illustration of a method for controlling the transfer rate to prevent a sharp increase in the machining load during machining of edge features through the Fine Diagnostic Logic submodule according to the present invention.
FIG. 5 is a diagram schematically illustrating a process of controlling the rotation speed of a spindle for stable machining without chatter when chatter is generated in the control module according to the present invention. FIG.

Hereinafter, other objects and features of the present invention will be apparent from the following description of embodiments with reference to the accompanying drawings.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, an intelligent CNC cutting and processing control system according to the present invention will be described with reference to an embodiment applied to a CNC machine tool equipped with a Numerical Control (NC) and a Programmable Logic Controller (PLC).

1 is a conceptual diagram showing an intelligent CNC machine tool control system according to the present invention.

Referring to FIG. 1, an intelligent CNC machine tool control system 1 according to the present invention is coupled to a CNC machine tool, and is configured in the following steps.

First, the data transfer module 10 receives information on the machining operation of the machine tool from the controller of the CNC machine tool through the communication interface submodule 11 such as Ethernet in real time, such as the machining position of the machining tool, machining time, And receives the physical property values of the cutting process from the plurality of sensors (12).

The synchronization mapping module 20 synchronizes and maps the physical property values received from the plurality of sensors 12 with respect to the processing position and processing time received from the communication interface submodule 11, And a synchronization monitoring sub module 21 for displaying information on the screen.

The diagnostic module 30 determines whether or not the machining state is bad and productivity through the mapping logic acquired through the synchronization mapping module 20. The diagnostic module 30 includes a diagnostic module 30 for displaying the information of the diagnostic module 30 on the screen, An information monitoring submodule 31 and a fine diagnosis logic submodule 32 for precisely diagnosing the machining state.

The control module 40 controls cutting conditions so as to change the defective machining state to a high quality machining state based on the diagnosis module 30, and controls the cutting machining conditions so as to increase the machining speed within a high quality machining range .

The communication interface submodule 11 of the data transfer module 10 is used to transmit information such as a machining position and a machining time of a machining tool in a machining coordinate system in real time during a machining operation. The communication method is parallel, serial, Ethernet, And so on.

The plurality of sensors 12 of the data transfer module 10 are installed in a CNC machine tool to sense different physical property values. For example, the sensors 12 are installed in a CNC machine tool to measure a machining tone of the tool. An acoustical sensor, an accelerometer sensor that measures the vibration generated in the machining tool and spindle spindle during machining, and a current sensing sensor that measures the amount of input current of the spindle spindle motor to measure the machining load generated on the spindle spindle during machining.

The plurality of sensors measure the physical characteristics such as processing load and vibration generated when a CNC machine tool is machined with a machining tool mounted on a spindle of a spindle, and the number and specifications of the sensors can be different have.

In addition, in the case of acoustic sensors, in order to more precisely measure the physical characteristic value generated at the point where the processing tool processes the material, the shape of the object having the directivity toward the processing point, It is preferable to be further bonded.

The current sensor for measuring the machining load of the spindle equipped with the machining tool is installed at the input terminal of the spindle motor, and the accelerometer sensor for sensing the machining vibration is preferably mounted on the spindle of the spindle and the machining table.

Meanwhile, among the signals transmitted from the plurality of sensors, the analog signal is preferably converted into digital signal data through a DAS (Data Acquisition System).

The synchronization mapping module 20 transmits the measured values of the sensors obtained from the plurality of sensors 12 of the data transfer module 10 and the machining position (X, Y, Z) of the machining tool to the communication interface submodule 11 , And maps the physical result values acquired by the plurality of sensors 12 synchronized with the machining time by machining positions synchronized with machining time.

Then, the synchronization mapping module 20 displays physical processing values corresponding to the machining position and the machining time on the screen through the synchronization monitoring sub-module 21 so that the machining-related researcher and the worker can determine the machining time sequence and the machining position sequence And the pattern of the physical property value can be confirmed by the graph method, and the researcher and the worker related to the processing can utilize the confirmed pattern as the data for analysis and prediction of the processing state.

The diagnostic module 30 analyzes the data acquired through the synchronization mapping module 20 to diagnose whether the processing is defective and productivity, and displays the diagnostic information through a diagnostic information monitoring submodule 31 And the precise diagnosis logic sub-module 32 for diagnosing using the CNC information and the sensor data in combination, will be described together with the use state of the diagnosis module 30 through the following embodiments.

The control module 40 analyzes the data acquired through the diagnosis module 30 to diagnose whether the machining is defective or not, and then controls the feed speed and spindle rotational speed to be changed or controlled based on high quality machining conditions, The feed speed and the main shaft rotation speed are controlled so as to be upwardly changed and controlled.

First, the failure due to the chatter vibration is determined by the FFT analysis and the FRF analysis processing among the sensor detection values obtained through the accelerometer sensor attached to the main spindle and the acoustic sensor installed at the processing point, do. At this time, Fast Fourie Transforms (FFT) analysis and Frequency Response Fouction (FRF) analysis are performed by using the existing theory of cutting dynamics.

For example, when FFT analysis of vibration data is performed, the excitation frequency at which the cutting tool is machined is calculated by the number of cutting tools and the spindle spindle RPM of the main spindle. A chatter occurs when the magnitude of the vibration increases, and the diagnostic module 30 diagnoses the failure due to the chatter.

Next, the method of analyzing the degree of productivity is based on the vibration characteristics obtained from the accelerometer sensor among the plurality of sensors, the non-cutting resistance of the workpiece, the torque of the main spindle of the CNC machine tool (data obtained from the CNC- Therefore, the optimum range of the machining load capable of performing stable machining is searched, and in particular, the degree of productivity is diagnosed based on the upper limit value within the optimum range of the machining load. For example, if the processing load has a processing load that is 20% or less lower than the upper limit within the optimum range of the processing load, the diagnostic module diagnoses that the productivity has deteriorated.

At this time, the diagnostic information such as the range of the optimal processing load calculated by the diagnostic module 30 and the measured values related to the machining load is displayed on the screen through the diagnostic information monitoring sub-module 31 as diagnostic texts, graphics, The status of the workpiece and the quality of the machining are displayed on the screen.

The precise diagnosis logic sub-module 32 analyzes the data of the synchronization mapping module 20 and the diagnosis information diagnosed through the diagnosis module 30 to precisely diagnose the processing state.

At this time, the operating status of the precise diagnosis logic sub-module 32 may be, for example, a state in which the blade of the machining tool is damaged due to foreign matter or cutting chips of the work (workpiece) The defect of the tool can be diagnosed. That is, the machining tool has 2 to 4 blades as a rotating tool, and each blade has a characteristic vibration characteristic of each blade when the blade rotates for cutting by the spindle of the main shaft, and it can be grasped by FFT analysis. However, if the FFT analysis is confirmed in the case where the defect described above is confirmed, it is confirmed that the magnitude of the vibration in the excitation frequency and the harmonic frequency band for the abnormal blade is nearly or very small to '0'. Therefore, It is possible to diagnose the abnormality. In order to diagnose this failure phenomenon precisely, it is possible to diagnose by using a combination of the reduction of the machining load of the spindle due to the reduction of the machining area due to the abnormal blade.

FIG. 3 shows that the shaking of the cutting tool diagnosed through the above-described fine diagnosis logic submodule 32 is diagnosed through FFT analysis and then the rotation speed of the spindle is changed to control the shaking of the cutting tool.

As another example of the operation state of the fine diagnosis logic submodule 32, when the cutting is performed with a small-diameter tool (? 2 or less), the rigidity of the tool is low. Therefore, cutting conditions such as cutting depth and machining speed The depth is relatively thin and the speed is set relatively slow compared to the large diameter tool. This enables fine cutting with a cutting depth of 100 μm or less.

However, in the above-described fine cutting, since the shape of the small-diameter tool is a shape of a circular and elongated circular beam, the rigidity of the small-diameter tool may be relatively weak compared to the vibration characteristics and cutting load of the spindle motor, Can not be accurately detected.

In order to solve this problem, the precision diagnosis logic sub-module 32 performs an FFT analysis on the cutting vibration of the small-diameter tool and an FFT analysis on the vibration of the main spindle motor, Only the frequencies due to the cutting vibration of the small-diameter tool are obtained by removing the values corresponding to the vibration of the spindle motor. If the size of the frequency due to the cutting vibration of the small tool is converted into a size larger than the vibrating frequency of the spindle motor and the patterns and sizes of the first to sixth frequencies are analyzed, it is possible to accurately grasp whether the small tool is broken or not.

As another example of the operating state of the precise diagnosis logic sub-module 32, if a certain machining time elapses during machining with the machining tool, wear of the machining tool occurs and if the wear continues, There is a problem that serious machining failure occurs due to breakage of the tool. In the current CNC machine tool machining area, the operator does not perceive the wear and breakage of the tool by visually obstructing the visual field of the worker, Because it is judged only by the sound, quick and accurate diagnosis is not done.

In order to solve this problem, the precise diagnosis logic sub-module 32 can diagnose the state of the machining failure through the pattern of the spindle load value of the CNC and the current sensor installed on the spindle.

That is, the processing load increases gradually as the processing tool wears, and when the processing tool experiences serious wear, the processing load increases rapidly, and the processing load dips at a certain point. This is because the cutting edge of the machining tool is broken by the surge of the machining load, and the machining load is reduced while the cutting amount is reduced. However, the pattern of the machining load may similarly occur in a section in which rapid movement is performed, not in actual machining even when the cutting edge of the machining tool is in a normal state, so that it is necessary to accurately diagnose whether it is a rapid movement section or a defect due to a tool breakage.

The precise diagnosis logic submodule 32 secures a machining NC code for instructing the CNC cutting path in advance, and obtains information on the cutting speed of the CNC machining subassembly in accordance with the information obtained by classifying the cutting feed section (G01 command section) and the rapid feed section (G00 command section) And when the pattern of the main axis spindle machining load of the current sensor and the CNC shows a sharp decrease in the high-strength load due to the breakage of the tool blade in the cutting and conveying section, the machining tool blade It is possible to precisely diagnose the breakage and the machining defects.

As an example of another operating state of the precise diagnosis logic sub-module 32, an excessive processing load is generated at the corners or the like during machining of the workpiece, thereby causing breakage of the machining tool and jamming of the machining tool. It is possible to diagnose that the processing defects such as machining dimensional errors and the like are caused.

That is, the precise diagnosis logic sub-module 32 utilizes the machining load pattern mathematically calculated from the machining NC code and the machining load pattern of the actual machining from the current sensor attached to the spindle spindle, so that the excessive machining load The moving speed of the machining tool is lowered before the machining tool enters the generated portion to prevent the occurrence of the overload.

More specifically, the machining load pattern calculated from the machining NC code is very similar to the machining load pattern of the physical machining, but the machining load value is different. The difference in the magnitude of the machining load in the two patterns is because the physical machining load is larger than the mathematical calculation value due to wear of the machining tool which is not reflected in the NC code.

The machining load pattern calculated from the machining NC code is information that can be used to grasp and predict the pattern of the machining load. Based on this, it is possible to predict the part where the excessive machining load is generated through the machining load pattern calculated from the machining NC code Through the diagnosed information, the precise diagnosis logic sub-module 32 predicts breakage or the like of the machining tool and reduces the moving speed of the machining tool before machining such as a corner portion.

Fig. 4 is a conceptual diagram illustrating the above embodiment. Fig. 4 is a conceptual diagram illustrating the above embodiment. In this embodiment, a combination of a mathematical load (lower pattern) calculated from the NC code and the actual machining load (upper pattern) FIG. 2 is a conceptual diagram illustrating a concept of controlling an actual machining load so as not to be overloaded by controlling a feed rate by precise diagnosis and advance precedence control in order to prevent machining overload and damage to the machining tool and breakage of the machining tool.

The control module 40 controls the cutting conditions so that the defective machining state can be switched to a high quality machining state based on the diagnosis calculated by the diagnosis module 30, To a cutting condition capable of achieving high productivity within the cutting tool.

First of all, the diagnosis module 30 diagnoses defects due to chatter vibrations as in the first embodiment. If the diagnosis module 30 diagnoses defects due to chatter vibrations as in the first embodiment, Change the RPM to eliminate chatter vibration and ensure good quality machining. At this time, it is preferable to select the maximum RPM within the allowable RPM range of the change range of the RPM of the main spindle, and control the cutting condition to the maximum RPM.

In the case of the second embodiment described later, the machining speed is increased and the productivity is improved by changing and controlling the cutting condition at the maximum speed in the optimum machining range.

In the machining operation for fine cutting with the small-diameter tool of the third embodiment described above, damage to the workpiece and defective machining are prevented by replacing the small-diameter tool before the small-diameter tool is broken. This is implemented by instructing the control module 40 to immediately exchange the small-diameter tool when an abnormality diagnosis of the small-diameter tool occurs through the diagnostic module.

That is, when the diagnosis of the third embodiment occurs, the control module 40 first instructs the replacement of the cutting tool, and the machining position for restarting with the replaced cutting tool is shifted from the machining NC code The machining position is controlled so as to perform the machining at the third machining position. This is for eliminating processing steps that may occur in the workpiece.

On the other hand, when the machining tool of the fourth embodiment described above is damaged due to wear and abrasion of the machining tool occurs, the machining position of the machining tool is changed as in the second embodiment The machining position is controlled so as to perform the machining at the third machining position before the machining position.

For the diagnosis of the corner portion of the above-described fifth embodiment, the change of the cutting condition is controlled at a feed speed not exceeding the upper limit of the optimum machining load range of the second embodiment.

As a method of controlling the speed of the main spindle, the rotational speed of the spindle can be checked by comparing the acoustic frequency acquired through the microphone among the plurality of sensors 12 by contrast.

The formula used in the process of controlling the rotation speed of the spindle using the acoustic frequency acquired through the microphone is expressed by Equation (1).

Where F _t is the oscillation frequency of the machining tool, RPM is the spindle rotation rate per minute, and N _t is the number of machining tools.

If chatter vibration occurs in the machining tool among the values sensed by the plurality of sensors 12, the speed of the spindle is controlled by the following equation (2).

Equation (2) changes the spindle speed (RPM) at which the chatter is generated to the RPM corresponding to the frequency and harmonic frequency of the machining tool capable of stable machining.

는 가공공구의 날수 K=1,2,3,4,...이다.Where RPM _n is the chatter-free spindle speed, ω _c is the spindle RPM at which chatter occurs,

Is the number of teeth of the tool K = 1, 2, 3, 4, ....

5 is a flowchart showing solving chatter vibration of a machining tool using Equation (2).

More specifically, when the control module 40 instructs the driving of the machining program, the machining path of the machining tool is confirmed after confirming the corresponding drive command (S10), and it is confirmed whether or not the active control is performed S20).

When the active control is performed, a load and a fast Fourier transform (FFT) transmitted to the spindle are confirmed (S30), and it is confirmed whether the vibration is detected or exceeded the threshold (S40).

If a tremor is found or exceeded the critical value, a new RPM is provided through the above equation (2) or the transfer speed of the object to be processed is changed (S50). Thereafter, the process returns to step S40 to confirm whether the shaking has been found or exceeded the threshold through the changed RPM, and repeats the process of providing the new RPM again if the shaking is found or the threshold is exceeded.

If no tremor is detected or the threshold is not exceeded, it is determined whether to continue monitoring the machining tool (S760). If the monitoring is terminated, the process is stored (S80) and the next drive command is awaited.

At this time, if active control is not performed in step of determining whether or not to perform the active control, step S21 may be displayed through a separate monitoring module and simultaneously stored as data (S21).

In addition, the above intelligent CNC machine tool control system is not limited to showing mathematical model and mathematical data through existing software system when performing cutting-related training such as CAM (Computer Aided Manufacturing) Etc. can be displayed as knowledge data such as numerical values, patterns, and indications of badness. This allows the trainees and machine tool workers to provide some field experience in the CNC cutting and processing stage and can take the actual product quality into consideration. Furthermore, in the related tests such as certification, it is possible to perform an in - depth evaluation in consideration of objective and physical characteristics as compared with subjective and dependent evaluation of the existing evaluator.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains.

Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

1: Intelligent CNC machine tool control system according to the present invention
10: Data transfer module
20: Synchronization Mapping Module
30: Diagnostic module
40: Control module

Claims (6)

Processing information such as the machining position and machining time of the machining tool is received in real time through the communication interface submodule 11 connected to the controller of the CNC machine tool and is transmitted through the plurality of sensors 12 to the physical state A data transfer module (10) for receiving a property value of the data transfer module
The plurality of sensors 12 are connected to processing operation information, such as a processing position, a processing time, and the like, of a processing tool that is transmitted through the communication interface submodule 11 among the information transmitted through the data transfer module 10, A synchronization mapping module 20 for mapping the characteristic values of the physical conditions occurring during the cutting process so as to be associated with the machining operation information arranged in the progress order;
A diagnostic module (30) for comparing the mapped physical property value transmitted through the synchronization mapping module (20) with a pre-stored NC code and performing intelligent diagnosis through processing quality and processing productivity related diagnosis logic;
And a control module (40) for performing control to change machining conditions according to a diagnosis result of the diagnosis module (30). The diagnostic system of claim 1, wherein the diagnostic module (30)
A diagnostic information monitoring submodule (31) for displaying the diagnosed information on the screen, and a precision diagnostic logic submodule (32) for precisely diagnosing the machining state. The apparatus according to claim 1, wherein the plurality of sensors (12)
An acoustic sensor for measuring the machining noise generated when the cutting tool is cutting,
A current sensor for measuring a machining load which is transmitted to the main axis by the cutting tool during cutting,
An accelerometer sensor for measuring the vibration of the machining tool,
IR sensors and thermal imagers that measure the heat generated between the processing tool and the workpiece,
And a spindle machining load confirmation sensor provided inside the CNC machine tool and measuring a machining load transferred to the spindle. 4. The system according to any one of claims 1 to 3, wherein the diagnostic module (30)
Comparing the information transmitted through the synchronization mapping module 20 with a processed NC code,
The machining load pattern predicted mathematically through the machining NC code is compared with the machining position of the machining tool and the machining time among the characteristic values transmitted through the synchronization mapping module 20 to determine the degree of wear of the machining tool, Wherein the controller is configured to diagnose the intelligent CNC machine tool control system. 4. The system according to any one of claims 1 to 3, wherein the diagnostic module (30)
When a pattern in which the machining load is continuously increased during the machining of the machining tool and a pattern in which the machining load plunges close to '0' at a specific position and time appears, the machining tool is broken and the machining can not be practically performed Diagnosis,
The vibration characteristics of a plurality of blades arranged on a machining tool are analyzed through FFT analysis. In the case where the magnitude of the vibration in the blade frequency and harmonic frequency band is close to 0 or very small, or 2 Wherein abnormality of the blade of the machining tool is diagnosed on the basis of the abnormal physical property value when the magnitude of abnormal vibration increases. 4. The system according to any one of claims 1 to 3, wherein the diagnostic module (30)
The FFT analysis of the vibration occurring during the cutting operation of the small diameter tool and the FFT analysis of the vibration of the main axis spindle motor are performed and then the frequency of the main axis spindle motor in the frequency band where the excitation frequency of the two vibrations overlaps with the harmonic frequency After the relative values are removed and only the frequencies due to the cutting process vibration of the small diameter tool are acquired, the magnitude of the frequency due to the cutting process vibration of the small diameter tool is converted into the size larger than the excitation frequency of the main axis spindle motor, And diagnoses whether the small-diameter tool is damaged or not by analyzing the pattern and size of the small-diameter tool.

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