WO2018119845A1

WO2018119845A1 - State detection method and system for numerical control machine tool

Info

Publication number: WO2018119845A1
Application number: PCT/CN2016/112958
Authority: WO
Inventors: 佟荣磊
Original assignee: 深圳配天智能技术研究院有限公司
Priority date: 2016-12-29
Filing date: 2016-12-29
Publication date: 2018-07-05
Also published as: CN109496285A

Abstract

Disclosed are a state detection method and system (10) for a numerical control machine tool, wherein the method comprises: detecting a vibration signal generated by a numerical control machine tool during a working process; converting the vibration signal from a time domain to a frequency domain; and determining a working state of the numerical control machine tool according to frequency domain information about the vibration signal or according to a combination of frequency domain information and time domain information about the vibration signal. A working state of a numerical control machine tool is determined according to a vibration signal generated by the numerical control machine tool during a working process, a detection method can be achieved with an algorithm, the cost is low, and unified monitoring of the numerical control machine tool can be achieved.

Description

State detection method and system for numerically controlled machine tools

[Technical Field]

Embodiments of the present invention relate to the field of numerical control, and in particular, to a method and system for detecting a state of a numerically controlled machine tool.

【Background technique】

The CNC workshop with high degree of automation can realize long-term unmanned production with the same processing and auxiliary processes. In view of this, the domestic factory continuously improves the automation degree of the CNC workshop, and the coverage of the numerical control machine tool is continuously expanded, so that the demand for the intelligent workshop management system of the cutting machine of the numerical control machine tool is continuously enhanced.

Condition monitoring of CNC machine tools can help producers confirm the machining status of CNC machine tools and optimize machining efficiency. However, at present, in the CNC workshops in domestic factories, the use systems of CNC machine tools are various, including domestic or imported; the use system of CNC machine tools is not only uneven in performance, but also the system interface is not matched. The intelligent workshop management system is difficult to achieve integrated monitoring of the machining status of CNC machine tools, or the monitoring cost is large.

[Summary of the Invention]

The embodiment of the invention provides a method and a system for detecting the state of a numerically controlled machine tool, so as to solve the problems that the intelligent workshop management system of the prior art can not realize the integrated monitoring of the processing status of the numerically controlled machine tool, or the monitoring cost is large.

In order to solve the above technical problem, a technical solution adopted by the embodiment of the present invention is to provide a state detecting method for a numerically controlled machine tool, and the method includes:

Receiving a vibration signal generated by the numerical control machine tool during the working process detected by the detecting device;

Converting the vibration signal from a time domain to a frequency domain;

Determining an operating state of the numerically controlled machine tool according to frequency domain information of the vibration signal or a combination of the frequency domain information and the time domain information.

Wherein, the vibration signal is a noise signal generated during the working process of the numerical control machine tool.

The step of determining the working state of the numerically controlled machine tool according to the frequency domain information of the vibration signal or the combination of the frequency domain information and the time domain information includes:

Frequency domain information according to the vibration signal or frequency domain information and time domain information according to the vibration signal The combination of the information determines whether the vibration signal satisfies a preset state recognition condition;

If the state recognition condition is satisfied, the numerically controlled machine tool is in an operating state corresponding to the state recognition condition.

The step of determining, according to the frequency domain information of the vibration signal or the combination of the frequency domain information and the time domain information of the vibration signal, whether the vibration signal satisfies a preset state recognition condition includes:

Determining, according to frequency domain information of the vibration signal, whether a frequency of the vibration signal matches a preset processing frequency or a multiple of the processing frequency;

The CNC machine tool is in a machining state if it matches the machining frequency or the multiple of the machining frequency.

The step of determining, according to the frequency domain information of the vibration signal, whether the frequency of the vibration signal matches a preset processing frequency or a frequency multiplication of the processing frequency, further includes:

The machining frequency is set according to the machining tool and machining information of the numerical control machine tool.

Wherein, the step of setting the processing frequency according to the machining tool and the processing information of the numerical control machine tool comprises:

The processing frequency is calculated according to the following formula:

ω _T =(teeth×n)/60;

Where ω _T is the machining frequency, teeth is the number of teeth of the machining tool, and n is the number of revolutions per minute of the machining tool.

Wherein, the detecting device detects that the sampling frequency of the vibration signal generated by the CNC machine tool during the working process is at least five times the processing frequency.

Determining, according to the time domain information of the vibration signal, whether the amplitude of the vibration signal is less than a preset first amplitude threshold, and determining, according to frequency domain information of the vibration signal, whether the frequency of the vibration signal is less than a preset value. First frequency threshold;

If the amplitude of the vibration signal is less than the first amplitude threshold, and the frequency of the vibration signal is less than the first frequency threshold, the numerical control machine is in a stop or feed hold state.

The step of determining, according to the frequency domain information of the vibration signal or the combination of the frequency domain information and the time domain information of the vibration signal, whether the vibration signal satisfies a preset state recognition condition The steps include:

Determining, according to time domain information of the vibration signal, whether the amplitude of the vibration signal is greater than a preset second amplitude threshold, and determining, according to frequency domain information of the vibration signal, whether the frequency of the vibration signal is less than a preset value. Second frequency threshold;

If the amplitude of the vibration signal is at least partially greater than the second amplitude threshold, and the frequency of the vibration signal is less than the second frequency threshold, the numerically controlled machine tool is in a collision state.

Determining, according to the time domain information of the vibration signal, whether the amplitude of the vibration signal is greater than a preset third amplitude threshold, and determining, according to frequency domain information of the vibration signal, whether the frequency of the vibration signal is greater than a preset value. Third frequency threshold;

The numerically controlled machine tool is in a dither state if the amplitude of the vibration signal is at least partially greater than the third amplitude threshold and the frequency of the vibration signal is at least partially greater than the third frequency threshold.

The step of detecting the vibration signal generated by the CNC machine tool during the working process further includes:

Receiving an identification mark of the numerical control machine tool;

After the step of determining the working state of the numerically controlled machine tool according to the frequency domain information of the vibration signal or the combination of the frequency domain information and the time domain information of the vibration signal, the method further includes:

Corresponding processing is performed according to the working state and the identification mark.

In order to solve the above technical problem, a technical solution adopted by the embodiment of the present invention is to provide a state detecting system for a numerically controlled machine tool, characterized in that the system comprises an analyzing device and a detecting device, wherein the detecting device comprises a sensor and a sampling device. a module and a first wireless communication module, the analyzing device comprising a second wireless communication module and a processor; wherein the sensor is configured to detect a vibration signal generated by the numerically controlled machine tool during operation, and the sampling module is configured to The vibration signal detected by the sensor is used for sampling, the first wireless communication module is configured to send the vibration signal sampled by the sampling module to the second wireless communication module, and the processor is configured to The vibration signal received by the second wireless communication module performs conversion from the time domain to the frequency domain, and determines the numerical control machine tool according to the frequency domain information of the vibration signal or the combination of the frequency domain information and the time domain information. Working status.

Wherein, the sensor is a sound sensor, and the vibration signal is a noise signal generated by the CNC machine tool during operation.

The processor determines, according to frequency domain information of the vibration signal or according to a combination of frequency domain information and time domain information of the vibration signal, whether the vibration signal satisfies a preset state recognition condition, if the The state recognition condition determines that the numerically controlled machine tool is in an operating state corresponding to the state recognition condition.

The processor determines, according to the frequency domain information of the vibration signal, whether the frequency of the vibration signal matches a preset processing frequency or a multiple of the processing frequency, if the processing frequency or the processing When the frequency multiplications match, it is determined that the numerically controlled machine tool is in a machining state.

The processor sets the processing frequency according to the machining tool and machining information of the numerical control machine tool.

The processor determines, according to time domain information of the vibration signal, whether an amplitude of the vibration signal is less than a preset first amplitude threshold, and determines a frequency of the vibration signal according to frequency domain information of the vibration signal. Whether it is less than a preset first frequency threshold, if the amplitude of the vibration signal is less than the first amplitude threshold, and the frequency of the vibration signal is less than the first frequency threshold, determining that the numerical control machine is Stop or feed in hold.

The processor determines, according to time domain information of the vibration signal, whether an amplitude of the vibration signal is greater than a preset second amplitude threshold, and determines a frequency of the vibration signal according to frequency domain information of the vibration signal. Whether it is less than a preset second frequency threshold, if the amplitude of the vibration signal is at least partially greater than the second amplitude threshold, and the frequency of the vibration signal is less than the second frequency threshold, determining the numerical control machine tool In a collision state.

The processor determines, according to time domain information of the vibration signal, whether an amplitude of the vibration signal is greater than a preset third amplitude threshold, and determines a frequency of the vibration signal according to frequency domain information of the vibration signal. Whether it is greater than a preset third frequency threshold, if the amplitude of the vibration signal is at least partially greater than the third amplitude threshold, and the frequency of the vibration signal is at least partially greater than the third frequency threshold, determining the numerical control The machine is in a dither state.

The sampling module associates the vibration signal with an identification mark of the numerically controlled machine tool set in advance, and then sends the vibration signal to the analysis device through the first wireless communication module, and the analysis device is configured according to the working state and the The identification mark is processed accordingly.

The beneficial effects of the embodiment of the present invention are: in the system and method for detecting the state of the numerical control machine tool provided by the embodiment of the present invention, determining the working state of the numerically controlled machine tool according to the vibration signal generated during the working process of detecting the numerical control machine tool, the detecting method It can be realized by an algorithm, the cost is low, and the unified monitoring of the numerical control machine tool can be realized.

[Description of the Drawings]

1 is a schematic flow chart of a first embodiment of a state detecting method for a numerically controlled machine tool according to the present invention;

2 is a schematic flow chart of a second embodiment of a state detecting method for a numerically controlled machine tool according to the present invention;

3 is a partial flow chart showing the machining state of the numerical control machine tool in the second embodiment;

4 is a partial flow chart showing the shutdown or feed hold state of the numerical control machine tool in the second embodiment;

Figure 5 is a partial flow chart showing the state of the collision of the numerically controlled machine tool in the second embodiment;

6 is a partial flow chart showing a flutter state of a numerically controlled machine tool in a second embodiment;

7 is a schematic flow chart of a third embodiment of a state detecting method for a numerically controlled machine tool according to the present invention;

Figure 8 is a block diagram showing the structure of a first embodiment of a state detecting system for a numerically controlled machine tool according to the present invention.

【detailed description】

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. 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 obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

As shown in FIG. 1, FIG. 1 is a schematic flow chart of a first embodiment of a state detecting method for a numerically controlled machine tool according to the present invention. In this embodiment, the working state of the numerically controlled machine tool is judged based on detecting the vibration signal generated by the numerically controlled machine tool during the working process. Specifically, the calibration method of this embodiment includes the following steps:

Step S11: Receiving a vibration signal generated by the numerical control machine tool detected by the detecting device during the working process.

The CNC machine tool is an automatic machine tool equipped with a program control system. When the CNC machine tool is working, it will generate a vibration signal due to the cutting action. The numerical control machine tool is provided with an analysis device and a detection device. The analysis device receives the vibration signal generated by the numerical control machine tool detected by the detection device during the working process, and processes the vibration signal. The following will describe in detail how to deal with it. . Wherein, the analyzing device and the detecting device may be two separate devices, or may be two device modules of one total device.

The detecting device is a sensor. In this embodiment, the vibration signal is a noise signal generated by the CNC machine tool during the working process, the detecting device is a noise sensor, and the noise sensor is also a sound sensor, and the sound sensor functions as a microphone or a microphone, and the sound sensor is used as a microphone or a microphone. To receive sound waves and convert the sound signals into electrical signals.

Step S12: Performing a conversion from the time domain to the frequency domain on the vibration signal.

The vibration signal collected by the detecting device is a time domain signal, and the time domain is the only objectively existing domain, and the time domain can be The shape of the signal is visually observed, but the signal cannot be accurately described with limited parameters. For example, the noise signal detected by the noise sensor is the time domain signal, and the amplitude of the noise signal changes not only with time but also with the frequency information. Related, this requires further analysis of the frequency structure of the noise signal, and describes the noise signal in the frequency domain, the frequency domain of the independent variable is the frequency of the noise signal, that is, the horizontal axis is the frequency, and the vertical axis is the amplitude of the frequency signal, The frequency domain is also a mathematical category domain that follows certain rules. Frequency domain analysis can decompose complex signals into superpositions of simple signals (such as sinusoidal signals), which can more accurately understand the "construction" of signals, through Fourier transform, The vibration signal is converted from the time domain to the frequency domain.

Step S13: determining the working state of the numerically controlled machine tool according to the frequency domain information of the vibration signal or according to the combination of the frequency domain information and the time domain information of the vibration signal.

The frequency domain information converted by the vibration signal or the combination of the frequency domain information and the time domain information of the vibration signal, and the frequency domain information of the vibration signal corresponding to the preset state in the system or the frequency domain information of the corresponding vibration signal The combination of the time domain information is compared to determine the working state of the numerically controlled machine tool. The preset state in the system includes the machining state, the stop or feed hold state, the collision state, and the flutter state, which will be described in detail later, and will not be described here.

In the system and method for detecting the state of the numerical control machine tool provided by the embodiment of the present invention, the working state of the numerically controlled machine tool is judged according to the vibration signal generated during the working process of the numerical control machine tool, and the detection method can be realized by an algorithm with low cost. And can achieve unified monitoring of CNC machine tools.

2 to FIG. 6, FIG. 2 is a schematic flow chart of a second embodiment of a state detecting method for a numerically controlled machine tool according to the present invention, and FIG. 3 to FIG. 6 are respectively a second embodiment of detecting whether a numerically controlled machine tool is in a processing state, A partial flow diagram of the shutdown or feed hold status, collision status, and dither status. The steps S21-S22 are substantially the same as the steps S11-S12 of the first embodiment, and are not described herein again. The difference between this embodiment and the first embodiment is that the embodiment further includes the following steps:

Step S23: determining whether the vibration signal satisfies a preset state recognition condition according to the frequency domain information of the vibration signal or the combination of the frequency domain information and the time domain information of the vibration signal.

In this embodiment, the vibration signal is a noise signal generated by the numerical control machine tool during the working process. The preset state recognition condition mainly includes a preset time domain information parameter of the noise signal or a combination of the time domain information parameter of the noise signal and the frequency domain information parameter. Specifically, the time domain information parameter of the noise signal includes the first amplitude threshold. And a second amplitude threshold and a third amplitude threshold; the frequency domain information parameter of the noise signal includes a frequency multiplication of the processing frequency or the processing frequency, a first frequency threshold, a second frequency threshold, and a third frequency threshold.

Step S24: If the state recognition condition is satisfied, the numerical control machine tool is in an operation state corresponding to the state recognition condition.

The working state of the CNC machine tool mainly includes the machining state, the stop or feed hold state, the collision state and the flutter state. The following describes the different working states in detail.

As shown in FIG. 3, when the operating state of the numerically controlled machine tool is the machining state, steps S23 and S24 are replaced with steps S231 and S241, respectively.

Step S231: Determine whether the frequency of the vibration signal matches the preset processing frequency or the frequency multiplication of the processing frequency according to the frequency domain information of the vibration signal.

Step S241: If the machining frequency or the frequency multiplication of the machining frequency is matched, the numerically controlled machine tool is in the machining state.

Specifically, before step S231, the processing frequency is set according to the machining tool and the machining information of the numerical control machine tool. Among them, the calculation formula for setting the machining frequency according to the machining tool and machining information of the CNC machine tool is as follows:

ω _T =(teeth×n)/60;

Where ω _T is the machining frequency, teeth is the number of teeth of the machining tool, and n is the revolutions per minute of the machining tool. According to the sampling theorem, the sampling frequency needs to be two to three times higher than the frequency of the sampling. In the embodiment, the detecting device detects that the sampling frequency of the vibration signal generated by the numerically controlled machine tool during the working process is set to at least five times the processing frequency.

In the specific application example, when a teeth is a 4-tooth tool and n is 3000 rpm (RPM), it can be concluded that the machining frequency ω _T of the CNC machine is 200 Hz. In the machining of CNC machine tools, the overall structural vibration of CNC machine tools is relatively rare. The flutter is mostly the natural frequency of the CNC machine tool and the processing frequency and its multiplication frequency are close. Therefore, it is more economical not to consider the natural frequency of the CNC machine tool as a whole. The sampling frequency is set by the frequency of the working frequency of the numerically controlled machine tool, and the sampling frequency is calculated to be about 5000 Hz according to the formula of this frequency.

As shown in FIG. 4, when the operating state of the numerically controlled machine tool is the stop or feed hold state, step S23 and step S24 are replaced with step S232 and step S242, respectively.

Step S232: Determine whether the amplitude of the vibration signal is less than a preset first amplitude threshold according to the time domain information of the vibration signal, and determine whether the frequency of the vibration signal is less than a preset first frequency threshold according to the frequency domain information of the vibration signal.

Step S242: If the amplitude of the vibration signal is less than the first amplitude threshold, and the frequency of the vibration signal is less than the first frequency threshold, the numerically controlled machine tool is in the stop or feed hold state.

Specifically, the first amplitude threshold and the first frequency threshold are both smaller than the working amplitude and the operating frequency of the CNC machining state, that is, the amplitude of the vibration signal is low, and the vibration signal is a low frequency signal, and the numerical control machine is stopped or fed. On hold. In practical applications, the noise signal of the shutdown or feed hold state is mostly white noise, and its amplitude is normally distributed. The first amplitude threshold is greater than the maximum value of the white noise amplitude, and the first frequency threshold ranges from 10 Hz to 50 Hz. . Among them, the amplitude of the noise signal will be different due to the different installation positions of the noise sensor, and the environment of different workshops is different, and will not be described in detail here, and the actual situation is set.

As shown in FIG. 5, when the operating state of the numerically controlled machine tool is the collision state, steps S23 and S24 are replaced with steps S233 and S243, respectively.

Step S233: Determine whether the amplitude of the vibration signal is greater than a preset second amplitude threshold according to the time domain information of the vibration signal, and determine whether the frequency of the vibration signal is less than a preset second frequency threshold according to the frequency domain information of the vibration signal.

Step S243: If the amplitude of the vibration signal is at least partially greater than the second amplitude threshold, and the frequency of the vibration signal is less than the second frequency threshold, the numerically controlled machine tool is in a collision state.

The second amplitude threshold is greater than the working amplitude of the CNC machine tool processing state, and the second frequency threshold is less than the operating frequency of the CNC machine tool processing state, if the amplitude of the vibration signal is at least partially greater than the second amplitude threshold, and the vibration signal frequency is less than the The second frequency threshold, that is, the amplitude of the vibration signal is high, but the vibration signal is a low frequency signal, and the CNC machine tool is highly likely to have a collision. In a practical application example, the amplitude of the noise signal in the collision state is more than three times the amplitude of the noise signal in the processing state, and the frequency is lower than the processing frequency; the second amplitude threshold is set to three times the working amplitude, and the second frequency threshold is greater than The first frequency threshold is less than the processing frequency.

As shown in FIG. 6, when the operating state of the numerically controlled machine tool is the flutter state, step S23 and step S24 are replaced with steps S234 and S244, respectively.

Step S234: Determine whether the amplitude of the vibration signal is greater than a preset third amplitude threshold according to the time domain information of the vibration signal, and determine whether the frequency of the vibration signal is greater than a preset third frequency threshold according to the frequency domain information of the vibration signal.

Step S244: If the amplitude of the vibration signal is at least partially greater than the third amplitude threshold, and the frequency of the vibration signal is at least partially greater than the third frequency threshold, the numerically controlled machine tool is in a dither state.

Wherein, the third amplitude threshold and the third frequency threshold are both greater than the working amplitude and the operating frequency of the CNC machine tool processing state, if the amplitude of the vibration signal is at least partially greater than the third amplitude threshold, rather than all, and the frequency of the vibration signal is at least partially greater than At the third frequency threshold, that is, the amplitude of the vibration signal is high, and The vibration signal is a high frequency signal, and the CNC machine is in a dither state. In a practical application example, the amplitude of the noise signal in the dither state is greater than the amplitude of the noise signal in the processing state, and is smaller than the amplitude of the noise signal when the collision state is greater than the operating frequency or the frequency multiplication of the operating frequency; The amplitude threshold is greater than the operating amplitude and less than the second amplitude, and the third frequency threshold is set to a multiple of the processing frequency, such as 2 times, 3 times or 4 times. In the production process, in general, the chattering of CNC machine tools is undesirable.

The steps of the working states of the numerically controlled machine tool are described in detail, wherein the working amplitude and the working frequency of the machining state are designed according to the noise sensor installation position and the environment of the workshop, and the stop or feed state, the collision machine The state and the flutter state are controlled by the CNC machine based on the machining state. The method for detecting the state of the numerical control machine tool provided by the invention determines the various working states of the numerical control machine tool according to the vibration signal generated by the detection of the numerical control machine tool in the working process, and the various working states satisfy the entire working process of the numerical control machine tool, the detection The method can realize the monitoring of the numerical control machine tool.

As shown in FIG. 7, FIG. 7 is a schematic flow chart of a third embodiment of a state detecting method for a numerically controlled machine tool according to the present invention. This embodiment includes the following steps:

Step S31: Receiving a vibration signal generated by the numerical control machine tool detected by the detecting device during the working process.

It can be described in the above S11, and will not be described herein.

Step S32: Receiving an identification mark of the numerical control machine tool.

In this embodiment, the numerical control machine tool works in a numerical control system, and the detection device and the analysis device of the numerical control machine tool are two separate devices, wherein the detection device is a sensor, the analysis device is a smart device, and the analysis device can be a computer, It can be a mobile device, and the data transmission between the detection device and the analysis device of the numerical control machine tool is performed via a wireless network. The analyzing device has an identification mark for each connected numerical control machine detecting device, so that one analyzing device can communicate with the detecting devices of the plurality of numerical control machine tools, and the identification mark of the detecting device of each numerical control machine tool is unique in the same wireless local area network. The identification mark is IP, which can be automatically assigned or manually assigned, and the analysis device identifies the monitored CNC machine tool by an identification mark (IP). Among them, the transmission mode of the wireless network may be any one of ZigBee, Buletooth, and Wifi, and the specific priority is Wifi. The Wifi has the characteristics of wide transmission distance, fast transmission rate, and high interoperability, and is suitable for the numerical control machine tool. Workshop environment.

Step S33: Performing a conversion from the time domain to the frequency domain on the vibration signal.

It can be described in the above S12, and will not be described herein.

Step S34: determining the working state of the numerically controlled machine tool according to the frequency domain information of the vibration signal or according to the combination of the frequency domain information and the time domain information of the vibration signal.

It can be described in the above S13, and will not be described herein.

Step S35: Perform corresponding processing according to the working state and the identification mark.

The analyzing device performs corresponding processing according to the working state and the identification mark, and the corresponding processing includes but is not limited to display, transmission or storage. The display interface of the analysis device can display the working state of the CNC machine tool, which is beneficial for the user to know the state of the CNC machine tool in time, can optimize the use efficiency of the CNC machine tool, and can be stopped in time when an accident occurs, so as to avoid more damage in the accident; The working status can be sent to the user's smart terminal, so that the user can control the state of the CNC machine at any time; the analysis device can also store the working state locally, for researching or analyzing the peak period of the accident of the CNC machine tool.

Please refer to FIG. 8. FIG. 8 is a schematic structural diagram of a first embodiment of a state detecting system for a numerically controlled machine tool according to the present invention.

As shown in FIG. 8, the state detecting system 10 includes an analyzing device 200 and a detecting device 100. The detecting device 100 includes a sensor 130, a sampling module 120, and a first wireless communication module 110. The analyzing device 200 includes a second wireless communication module 210. And a processor 220; wherein the sensor 130 is configured to detect a vibration signal generated by the numerically controlled machine tool during operation, the sampling module 120 is configured to sample the vibration signal detected by the sensor 130, and the first wireless communication module 110 is configured to use the sampling module The 120 samples of the vibration signal are sent to the second wireless communication module 210, and the processor 220 is configured to perform the time domain to the frequency domain conversion on the vibration signal received by the second wireless communication module 210, and according to the frequency domain information of the vibration signal. Or judge the working state of the numerically controlled machine tool according to the combination of the frequency domain information of the vibration signal and the time domain information.

In this embodiment, the sensor 130 is a sound sensor, which can convert the sound signal into an electrical signal, and the vibration signal is a noise signal generated by the CNC machine tool during the working process. In practical applications, the sound sensor should be as close as possible to the cutting area of the CNC machine tool. The sound sensor can obtain the noise information of the entire processing area, so that one CNC machine tool only needs one noise sensor to work together, which saves cost.

The first wireless communication module 110 and the second wireless communication module 210 are transmitted through a wireless network, and the transmission mode of the wireless network may be any one of three types: ZigBee, Buletooth, and Wifi. The specific priority is Wifi, and the Wifi has a wide transmission distance. It has the characteristics of high transmission rate and high interoperability. It is very suitable for the workshop environment of CNC machine tools, especially in places with harsh environment, wide geographical distribution and high automation.

The sampling module 120 is configured to sample the vibration signal detected by the sensor 130, and the sampling module 120 associates the vibration signal with the identification mark of the preset numerical control machine tool, and then sends the vibration signal to the analysis device 200 through the first wireless communication module 110, and the analysis device 200 corresponding processing according to the working state and the identification mark, specifically, the corresponding processing includes displaying the working state of the numerical control machine tool on the display interface of the analyzing device; transmitting the working state to the intelligent terminal of the user; storing the working state in the working state Local and many more.

In actual production, the power supply of the detecting device 100 can be provided by the electrical cabinet of the numerical control machine tool. The detecting device 100 is placed in the processing area of the numerically controlled machine tool during use, and the detecting device 100 needs to be installed with the fixing device and the protective device to prevent The damage of the cutting fluid and the chip to the sensor 130 and the collecting module 120; the sound sensor 130 should be as close as possible to the cutting area of the CNC machine tool, and the sound sensor 130 and the collecting module 120 detect and collect the noise signal generated by the CNC machine tool during the working process, and collect the noise signal. The module 120 performs an acquisition task by using a preset sampling frequency and a sampling period, and converts the collected data into an upper detection device protocol frame, and sends the data to the analysis device 200 through the first wireless communication module 110. After the second wireless communication module 210 of the analyzing device 200 receives the noise signal, the processor 220 performs analysis and filtering to obtain clean processing noise, and then processes the signal in the time domain and the frequency domain to obtain practical information related to cutting. Therefore, the processing state of the machine tool is determined. Specifically, the analyzing device 200 may be a smart device that analyzes the machining state of the numerically controlled machine tool running under different operating systems. The built-in software of the analyzing device 200 supports viewing and configuring the key segment of the detecting device 100. The processor 220 acquires a time domain signal of the processing noise, and performs noise reduction, filtering, frequency domain conversion, etc., and then calculates a processing frequency according to the tool information and the processing information, thereby setting a distinctive characteristic sound (the sounder can be customized separately) , such as buzzers, etc., to match the noise characteristics in the time domain.

The corresponding steps in the foregoing method embodiments are all performed by the processor 220 of the analyzing device 200. Therefore, the processor 220 is not described herein. For details, refer to the description of the corresponding steps.

The system 10 for numerically controlled machine tool state detection provided by the embodiment of the present invention may be composed of one analysis device 200 and a plurality of detection devices 100, so that one analysis device 200 can simultaneously monitor multiple detection devices 100. The analyzing device 200 can realize the monitoring processing state of each CNC machine tool in the numerical control workshop by using software, thereby counting the processing efficiency of the numerical control machine tool, saving labor for the CNC cutting occasion with high automation degree, the system can realize long-time monitoring and statistics, and effectively shorten the shutdown. Time, cost savings. In addition, in order to meet the unmanned production demand, the analysis device 200 can also transmit the collected data, the analysis data and the monitoring result to the mobile device of the producer in real time through the server, so that the producer can monitor the processing status outside the workshop.

In summary, those skilled in the art can easily understand that in the system and method for detecting the state of the numerical control machine tool provided by the embodiment of the present invention, the working state of the numerically controlled machine tool is judged according to the vibration signal generated during the working process of detecting the numerical control machine tool, The detection method can be realized by an algorithm, the cost is low, and the unified monitoring of the numerical control machine tool can be realized.

The above is only the embodiment of the present invention, and is not intended to limit the scope of the invention, and the equivalent structure or equivalent process transformation, or direct or indirect, using the description of the present invention and the contents of the drawings. The use of other related technical fields is equally included in the scope of patent protection of the present invention.

Claims

A state detecting method for a numerically controlled machine tool, characterized in that the method comprises:

Receiving a vibration signal generated by the numerical control machine tool during the working process detected by the detecting device;

Converting the vibration signal from a time domain to a frequency domain;

Determining an operating state of the numerically controlled machine tool according to frequency domain information of the vibration signal or according to a combination of frequency domain information and time domain information of the vibration signal.
The method of claim 1 wherein said vibration signal is a noise signal generated during operation of said numerically controlled machine tool.
The method according to claim 1, wherein the step of determining the operating state of the numerically controlled machine tool according to frequency domain information of the vibration signal or according to a combination of frequency domain information and time domain information of the vibration signal include:

Determining whether the vibration signal satisfies a preset state recognition condition according to frequency domain information of the vibration signal or according to a combination of frequency domain information and time domain information of the vibration signal;

If the state recognition condition is satisfied, the numerically controlled machine tool is in an operating state corresponding to the state recognition condition.
The method according to claim 3, wherein the determining whether the vibration signal satisfies a preset according to frequency domain information of the vibration signal or according to a combination of frequency domain information and time domain information of the vibration signal The steps of the status recognition condition include:

Determining, according to frequency domain information of the vibration signal, whether a frequency of the vibration signal matches a preset processing frequency or a multiple of the processing frequency;

The CNC machine tool is in a machining state if it matches the machining frequency or the multiple of the machining frequency.
The method according to claim 4, wherein said step of determining, according to frequency domain information of said vibration signal, whether said frequency of said vibration signal matches a predetermined processing frequency or a frequency multiplication of said processing frequency Previously, it further included:

The machining frequency is set according to the machining tool and machining information of the numerical control machine tool.
The method according to claim 5, wherein the step of setting the processing frequency according to the machining tool and machining information of the numerical control machine tool comprises:

The processing frequency is calculated according to the following formula:

ω T =(teeth×n)/60;

Where ω T is the machining frequency, teeth is the number of teeth of the machining tool, and n is the number of revolutions per minute of the machining tool.
The method according to claim 5, wherein said detecting means detects that the sampling frequency of the vibration signal generated by said numerically controlled machine tool during operation is at least five times said processing frequency.
The method according to claim 3, wherein the determining whether the vibration signal satisfies a preset according to frequency domain information of the vibration signal or according to a combination of frequency domain information and time domain information of the vibration signal The steps of the status recognition condition include:

Determining, according to the time domain information of the vibration signal, whether the amplitude of the vibration signal is less than a preset first amplitude threshold, and determining, according to frequency domain information of the vibration signal, whether the frequency of the vibration signal is less than a preset value. First frequency threshold;

If the amplitude of the vibration signal is less than the first amplitude threshold, and the frequency of the vibration signal is less than the first frequency threshold, the numerical control machine is in a stop or feed hold state.
The method according to claim 3, wherein the determining whether the vibration signal satisfies a preset according to frequency domain information of the vibration signal or according to a combination of frequency domain information and time domain information of the vibration signal The steps of the status recognition condition include:

Determining, according to time domain information of the vibration signal, whether the amplitude of the vibration signal is greater than a preset second amplitude threshold, and determining, according to frequency domain information of the vibration signal, whether the frequency of the vibration signal is less than a preset value. Second frequency threshold;

If the amplitude of the vibration signal is at least partially greater than the second amplitude threshold, and the frequency of the vibration signal is less than the second frequency threshold, the numerically controlled machine tool is in a collision state.
The method according to claim 3, wherein the determining whether the vibration signal satisfies a preset according to frequency domain information of the vibration signal or according to a combination of frequency domain information and time domain information of the vibration signal The steps of the status recognition condition include:

Determining, according to the time domain information of the vibration signal, whether the amplitude of the vibration signal is greater than a preset third amplitude threshold, and determining, according to frequency domain information of the vibration signal, whether the frequency of the vibration signal is greater than a preset value. Third frequency threshold;

The numerically controlled machine tool is in a dither state if the amplitude of the vibration signal is at least partially greater than the third amplitude threshold and the frequency of the vibration signal is at least partially greater than the third frequency threshold.
The method according to claim 1, wherein after the step of receiving the vibration signal generated by the numerical control machine tool during the operation of the detecting device, the method further comprises:

Receiving an identification mark of the numerical control machine tool;

The frequency domain information according to the vibration signal or the frequency domain information according to the vibration signal After the step of determining the working state of the numerically controlled machine tool by the combination of the domain information, the method further includes:

Corresponding processing is performed according to the working state and the identification mark.
A state detection system for a numerically controlled machine tool, characterized in that the system comprises an analysis device and a detection device, wherein the detection device comprises a sensor, a sampling module and a first wireless communication module, the analysis device comprising a second wireless communication module And a processor; wherein the sensor is configured to detect a vibration signal generated by the CNC machine tool during operation, the sampling module is configured to sample a vibration signal detected by the sensor, the first wireless communication module And the method is configured to send the vibration signal sampled by the sampling module to the second wireless communication module, where the processor is configured to perform time domain to frequency on the vibration signal received by the second wireless communication module Converting the domain, and determining the working state of the numerically controlled machine tool according to frequency domain information of the vibration signal or according to a combination of frequency domain information and time domain information of the vibration signal.
The system of claim 12 wherein said sensor is a sound sensor and said vibration signal is a noise signal generated during operation of said CNC machine tool.
The system according to claim 12, wherein the processor determines whether the vibration signal satisfies in advance according to frequency domain information of the vibration signal or according to a combination of frequency domain information and time domain information of the vibration signal. The set state recognition condition determines that the numerically controlled machine tool is in an operation state corresponding to the state recognition condition if the state recognition condition is satisfied.
The system according to claim 14, wherein said processor determines, according to frequency domain information of said vibration signal, whether a frequency of said vibration signal matches a preset processing frequency or a frequency multiplication of said processing frequency And if the processing frequency or the multiplication frequency of the processing frequency is matched, it is determined that the numerical control machine tool is in a processing state.
The system of claim 15 wherein said processor sets said machining frequency based on machining tools and machining information of said CNC machine.
The system according to claim 14, wherein the processor determines whether the amplitude of the vibration signal is smaller than a preset first amplitude threshold according to time domain information of the vibration signal, and according to the vibration signal The frequency domain information determines whether the frequency of the vibration signal is less than a preset first frequency threshold, if the amplitude of the vibration signal is less than the first amplitude threshold, and the frequency of the vibration signal is less than the first A frequency threshold determines that the CNC machine is in a stop or feed hold state.
The system according to claim 14, wherein the processor determines whether the amplitude of the vibration signal is greater than a preset second amplitude threshold according to time domain information of the vibration signal. And determining, according to the frequency domain information of the vibration signal, whether the frequency of the vibration signal is less than a preset second frequency threshold, if the amplitude of the vibration signal is at least partially greater than the second amplitude threshold, and the vibration signal If the frequency is less than the second frequency threshold, it is determined that the CNC machine is in a collision state.
The system according to claim 14, wherein the processor determines whether the amplitude of the vibration signal is greater than a preset third amplitude threshold according to time domain information of the vibration signal, and according to the vibration signal The frequency domain information determines whether the frequency of the vibration signal is greater than a preset third frequency threshold, if the amplitude of the vibration signal is at least partially greater than the third amplitude threshold, and the frequency of the vibration signal is at least partially greater than The third frequency threshold is determined to determine that the numerically controlled machine tool is in a dither state.
The system according to claim 12, wherein the sampling module associates the vibration signal with an identification mark of the numerically controlled machine tool set in advance, and then sends the vibration signal to the analysis device through the first wireless communication module. The analyzing device performs corresponding processing according to the working state and the identification mark.