Method and system for monitoring and evaluating cutting machining dust in working area of machine tool

Abstract

The invention belongs to the field of dust monitoring, and provides a method and a system for monitoring and evaluating cutting dust in a working area of a machine tool. According to the method, dust sensor point distribution is carried out based on spatial characteristics of a working area of a machine tool, multi-point multi-scale dust concentration information in the cutting machining process is collected, dust concentration data processing analysis and visualization are carried out based on a data fusion technology, and alarm indication is carried out when the dust concentration exceeds the standard. The system comprises a dust sensor module, a data transmission module, an upper computer module, a data visualization module and a standard exceeding alarm module. According to the invention, real-time acquisition and batch processing of the dust information of the working area of the machine tool in three dimensions of time, space and scale are realized, the dust distribution and concentration change rule in the machine tool can be revealed, and the dust in the working area of the machine tool can be analyzed and evaluated according to multiple evaluation indexes.

Description

Technical Field

[0001] The invention belongs to the field of dust monitoring, and relates to a method and system for monitoring and evaluating cutting dust in a working area of ​​a machine tool. Background Art

[0002] In the processing of high-end equipment in the aerospace field, high-speed metal cutting and cutting of certain special materials such as carbon fiber composite materials are very likely to generate a large amount of dust chips. The dust chips generated by these cutting processes are often of different sizes, ranging from micrometers to millimeters. Studies have shown that solid particles with an aerodynamic diameter of less than 75μm are very easy to suspend in the air and are difficult to settle in a short time. Long-term exposure to this dust can easily cause irritation to the skin and eyes of workers. After a large amount of inhalation, it is very easy to harm the health of the respiratory system. In severe cases, it may cause pneumoconiosis, renal failure, etc. Therefore, it is particularly important to prevent and control dust in the working area. However, many machine tools are not equipped with a dedicated dust collection system, and a small number of machine tools use wall suction or floor suction to extract the dust generated during the processing. This dust removal method is inefficient. It takes a lot of time to completely remove the dust, which affects the processing efficiency. Short-term negative pressure extraction is difficult to remove dust in the working area in time. When workers enter the working area of ​​the machine tool to clamp parts, adjust postures, etc., they are exposed to the dust environment for a long time, which seriously endangers their health.

[0003] In response to the monitoring problem of dust in different working environments, scholars in many fields such as construction, mining, and blasting have conducted research on related monitoring methods. The patent publication number of Li Li et al. is CN116519879, and the invention name is "A method and system for automatic monitoring of tunnel blasting dust". The method calculates the optimal layout of monitoring instruments according to the position of the support surface and the explosion energy, and monitors PM2.5 and TSP data. The layout method of this invention is formulated based on the tunnel explosion scene, so it is not suitable for dust monitoring during the cutting process in the working area of ​​the machine tool. The patent publication number of Zhao Cai et al. is CN116399773, and the invention name is "A system for monitoring dust in a construction environment". The system determines the optimal dust detection direction under different wind directions through calculation and analysis, and realizes the rapid detection of dust concentration in the construction environment. However, the air flow characteristics in the machine tool are more complicated due to the influence of negative pressure air source, machine tool movement, etc., and the wind direction factor cannot be considered alone. Therefore, it is not suitable for dust monitoring during the cutting process in the working area of ​​the machine tool. The patent publication number of Song Jiyuan et al. is CN117324148, and the invention name is "A patent for intelligent dust monitoring system at concrete production site". The system obtains the dust concentration of each dust detection point in each height layer of each dust sub-area at the concrete production site, analyzes and calculates the dust hazard index and issues an early warning. This method mainly analyzes and calculates the dust accumulation process in the height direction, while the machine tool pays more attention to the distribution of dust in the horizontal area. Therefore, this method is not suitable for dust monitoring during the cutting process in the working area of ​​the machine tool. The working area of ​​the machine tool is different from the construction site and the mine. It is not an open space, but generally a semi-enclosed or closed space. Dust is generated periodically with the cutting process, and is dispersed in the space due to the disturbance of the negative pressure air source and the movement of the machine tool. The staff enters the processing center according to the working hours and comes into intermittent contact with the dust environment. This difference makes many existing methods in similar fields unsuitable for monitoring and evaluating dust in the working area of ​​the machine tool. Therefore, how to accurately monitor and scientifically evaluate the cutting dust in the working area of ​​the machine tool in real time, and then guide the staff to arrange work hours so that they can start work when the dust concentration is lower than the safety threshold, is an important problem that needs to be solved urgently. Summary of the invention

[0004] Based on the above technical problems, the present invention provides a method and system for monitoring and evaluating cutting dust in the working area of ​​a machine tool. It can realize the real-time collection of dust information in the working area of ​​the machine tool in three dimensions: time, space, and scale, perform batch processing and analysis based on data fusion technology, and evaluate the dust in the machine tool based on multiple evaluation indicators.

[0005] The technical solution of the present invention:

[0006] A method for monitoring and evaluating cutting dust in a machine tool working area, the method comprising the following steps:

[0007] S1: Dust sensor placement based on the spatial characteristics of the machine tool working area;

[0008] S2: Use dust sensors to collect information on multi-point and multi-scale dust concentrations during cutting;

[0009] S3: The host computer obtains the data information of each dust sensor collected in step S2;

[0010] S4: Dust concentration data processing, analysis and visualization based on data fusion technology;

[0011] S5: Dust concentration safety threshold setting and exceeding the limit alarm indication.

[0012] Furthermore, the rules for distributing dust sensors based on the spatial characteristics of the machine tool working area described in step S1 are as follows: the dust sensors need to be evenly distributed on the side walls of the working area, with a certain distance between every two dust sensors, and the height of the monitoring point from the ground should be within the breathing zone of the workers; at the same time, areas where airflow passes or eddies are generated should be avoided.

[0013] Furthermore, the dust sensor in step S1 needs to have multiple monitoring channels, which can simultaneously monitor dust of multiple sizes including TSP (dust with an aerodynamic diameter less than 100 μm), PM10 (dust with an aerodynamic diameter less than 10 μm, and so on), PM2.5, and PM1.0.

[0014] Furthermore, the host computer described in step S3 needs to be equipped with a data acquisition interface and software, and each dust sensor is matched through the data acquisition interface, and each group of data collected by the dust sensor is unpacked and compiled to form a data file and temporarily stored in the specified path for subsequent batch processing and analysis and evaluation; in addition, the host computer must also have a dust sensor control function, and the dust sensor is controlled to start or stop working through the software in the host computer, and the calibration coefficients of different channels of the dust sensor are configured. At the same time, the working status of the dust sensor is monitored in real time, and a reconnection command is sent when the connection status of the dust sensor is abnormal.

[0015] Furthermore, the specific process of dust concentration data processing and analysis based on data fusion technology described in step S4 is as follows: the data read by the host computer covers the entire process before and after the machine tool works in terms of time, and involves multi-region dust distribution characteristics represented by multi-point dust sensors in space, and includes TSP, PM10, PM2.5, PM1.0 and other dust scales in terms of scale; the host computer needs to process the obtained data in real time and in batches based on data fusion technology, and update the dust concentration change curve and distribution diagram in real time according to the spatial area and dust scale classification; further, a scientific evaluation is carried out according to the relevant dust contact level assessment indicators, so as to guide the application of dust removal equipment and the working hours of the staff.

[0016] Furthermore, in step S4, the data fusion technology includes: (1) data preprocessing: standardizing and denoising the data to eliminate abnormal data and improve data quality. In addition, in order to address the problem of packet sticking and packet loss that is prone to occur during the transmission of string signals, a special buffer processing area is established in the preprocessing software to determine the string length. When the string length does not meet the preset length requirement, the data is discarded to ensure data consistency; (2) data alignment: using the timestamp synchronization method, the host computer system time is used as the reference time to synchronize the timestamps of all dust sensor return data to ensure that they can be compared and fused under the same reference frame; (3) feature-level fusion: processing the data returned by multiple dust sensors, extracting the concentration change characteristics of dust over time during the processing process, the distribution change characteristics of dust in space within the processing machine tool, and the differences in the above-mentioned spatiotemporal characteristics at different dust scales, and generating multi-scale dust concentration change curves, dust spatial distribution schematic diagrams, and dust contact level index evaluation results based on the feature-level fusion processing results.

[0017] Furthermore, the dust concentration safety threshold setting and excessive alarm indication in step S5: the dust concentration safety threshold setting needs to be performed based on the results of the dust concentration data processing and analysis in step 4, and a multi-channel electromagnetic relay is used to control the LED lights and buzzer alarm components to give an alarm indication when the dust concentration exceeds the standard in any area or scale within the machine tool working area.

[0018] A dust monitoring and evaluation system for cutting processing in a machine tool working area, the evaluation system comprising the following modules: a dust sensor module for obtaining dust concentration information in a machine tool space; a data transmission module, which needs to be adapted to the wiring requirements of the machine tool and is used to transmit data to a host computer; a host computer module, which needs to be equipped with relevant software to realize data collection, data processing, and sensor configuration functions; a data visualization module for visually displaying dust monitoring and evaluation results; and an over-standard alarm module for alarm indication when the dust concentration exceeds the standard.

[0019] The benefits of the present invention are: in view of the lack of accurate monitoring and scientific evaluation methods for cutting dust in the working area of ​​machine tools, which affects processing efficiency and endangers the health of workers, a method and system for monitoring and evaluating cutting dust in the working area of ​​machine tools is proposed. The dust sensors are arranged based on the spatial characteristics of the working area of ​​the machine tool, which to a certain extent avoids the influence of airflow disturbance on sensor sampling and improves the stability and accuracy of the monitoring results; the multi-channel laser dust sensor is used to synchronously monitor dust of multiple scales such as TSP, PM10, PM2.5, PM1.0, etc.; based on data fusion technology, the real-time collection and batch processing of dust information in the working area of ​​the machine tool in three dimensions of time, space and scale are realized, which can reveal the distribution and concentration change rules of dust in the machine tool, and analyze and evaluate the dust in the working area of ​​the machine tool based on multiple evaluation indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flow chart of a method for monitoring and evaluating cutting dust in the working area of ​​a machine tool;

[0021] Figure 2 A schematic diagram of a system for monitoring and evaluating cutting dust in a machine tool working area in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of dust sensor placement based on the spatial characteristics of a machining center in an embodiment of the present invention;

[0023] Figure 4 This is a flowchart of dust concentration data processing, analysis and visualization based on data fusion technology in one embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer and enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be noted that the technical solutions claimed to be protected by the present invention include but are not limited to the following embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative work should fall within the scope of protection of the present invention.

[0025] like Figure 1 As shown, an embodiment of the present invention provides a method and system for monitoring and evaluating cutting dust in a machine tool working area, specifically a method and system for monitoring and evaluating cutting dust in a large machining center, the method comprising the following steps:

[0026] S1: Dust sensor placement based on the spatial characteristics of the machine tool working area;

[0027] S2: Use dust sensors to collect information on multi-point and multi-scale dust concentrations during cutting;

[0028] S3: The host computer obtains the data information of each dust sensor collected in step S2;

[0029] S4: Dust concentration data processing, analysis and visualization based on data fusion technology;

[0030] S5: Dust concentration safety threshold setting and exceeding the limit alarm indication.

[0031] Furthermore, if Figure 2 As shown, the system includes the following modules: a dust sensor module, which is used to obtain dust concentration information in the machine tool space; a data transmission module, which needs to adapt to the machine tool wiring requirements and is used to transmit data to the host computer; the host computer module needs to have relevant software to realize data collection, data processing, and sensor configuration functions; a data visualization module, which is used to visualize the dust monitoring and evaluation results; an over-standard alarm module, which is used to alarm when the dust concentration exceeds the standard.

[0032] Furthermore, in step S1, the dust sensor placement based on the spatial characteristics of the machining center refers to: Figure 3 As shown in the figure, in order to accurately characterize the dust distribution at different locations in a large-scale machining center, dust sensors need to be evenly distributed on the side walls of the working area of ​​the machining center, with four dust sensors on each side and 1.6 meters between every two dust sensors. To ensure that the dust sensor monitoring point is in the breathing zone of the staff and avoids negative pressure air sources, air leakage gaps, corner grooves and other areas where airflow or eddy currents are easily generated, the dust sensor needs to be arranged at a height of 0.9 meters from the workbench, and each dust sensor is located at Figure 3 In the middle of the two dust collection square holes shown.

[0033] Furthermore, in step S2, the multi-point and multi-scale dust concentration information collection of the cutting process needs to use a multi-channel laser dust concentration sensor. Based on the principle of light scattering, the scattered light signal generated when the laser passes through the dust particles is converted into an electrical signal, and the dust concentration information of the area is obtained through calculation and analysis. The dust sensor monitoring channels include four different scales of monitoring channels, namely TSP, PM10, PM2.5 and PM1.0. In addition, the dust sensor module needs to be connected to a microprocessor and a small LCD display to display the dust mass concentration information of each scale in the area in real time.

[0034] Furthermore, in addition to the LCD screen displaying the monitoring results described in step S2, data can also be read by the method described in step S3: each dust sensor can establish communication with the host computer through serial communication protocols such as UART and I2C. Under the control of the host computer command, each dust sensor sends the collected data to the host computer in the form of a string. The host computer matches each dust sensor through port information, unpacks and compiles each group of data to form a data file and temporarily stores it in the specified path for subsequent batch processing and analysis and evaluation. The host computer must also have a dust sensor configuration function, control the dust sensor to start or stop working through the software in the host computer, and configure the calibration coefficients of different channels of the dust sensor to ensure the long-term accuracy of the system monitoring link. In addition, the host computer needs to monitor the working status of the dust sensor in real time, and send a reconnection command when the dust sensor connection status is abnormal to ensure the stability of the system operation.

[0035] Furthermore, in step S4, the dust concentration data processing, analysis and visualization based on data fusion technology are as follows: Figure 4 As shown, it includes: the host computer reads the temporarily stored collected data, which covers the whole process before and after the machining center works in time, and involves the multi-region dust distribution characteristics represented by multi-point dust sensors in space, and includes four dust scales of TSP, PM10, PM2.5, and PM1.0 in scale. The host computer needs to process the above data in real time and batch based on data fusion technology, and update the dust concentration change curve and distribution diagram in real time according to the spatial area and dust scale classification, so as to grasp the dust concentration change law and spatial distribution characteristics in the machining project, and then conduct scientific evaluation based on relevant dust contact level assessment indicators such as time-weighted average permissible concentration, short-time contact permissible concentration, contact limit ratio, etc., so as to guide the application of dust removal equipment and the working hours of staff.

[0036] Furthermore, in step S4, the data fusion technology includes: data preprocessing, which is to perform standardization and denoising before data fusion analysis to eliminate abnormal data and improve data quality. In addition, in order to address the problem of packet sticking and packet loss that is prone to occur during the transmission of string signals, a special buffer processing area is established in the preprocessing software to determine the string length and discard the data when it does not meet the preset length requirement to ensure data consistency; data alignment, which uses the timestamp synchronization method to synchronize the timestamps of all dust sensor return data with the host computer system time as the reference time to ensure that they can be compared and fused in the same reference frame; feature-level fusion, which processes the data returned by multiple dust sensors, extracts the concentration change characteristics of dust over time during the processing process, the distribution change characteristics of dust in space within the processing machine tool, and the differences in the above-mentioned spatiotemporal characteristics at different dust scales, and generates a multi-scale dust concentration change curve, a dust spatial distribution schematic diagram, and a dust contact level index evaluation result based on the feature-level fusion processing results.

[0037] Furthermore, in step S5, the dust concentration safety threshold setting and over-limit alarm indication refer to: according to the above-mentioned dust concentration evaluation index, the various concentration safety thresholds of multi-scale dust are determined, and according to the national standard "GB / Z 2.1-2019 Occupational Exposure Limits of Hazardous Factors in the Workplace" and the industry standard "T / CMIF 14-2017 Technical Specification for Green Design Product Evaluation Metal Cutting Machine Tools", the dust time-weighted average permissible concentration (PC-TWA) in the machining center is 3mg / m 3 That is, the time-weighted average concentration of dust that workers are exposed to during an 8-hour working day should be less than or equal to 3 mg / m 3 At the same time, the worker’s exposure level exceeds the value by 3 times the PC-TWA value, i.e. 9 mg / m 3 Each exposure should not exceed 15 minutes, and should not exceed 4 times during a working day, with a minimum interval of 1 hour; and in any case, it should not exceed 5 times the PC-TWA value, i.e. 15 mg / m 3 The electromagnetic relay controls the LED lights, buzzers and other alarm components to give an alarm indication when the dust concentration in any area or at any scale exceeds the above evaluation index.

Claims

1. A method for monitoring and evaluating cutting dust in a machine tool working area, characterized in that: The method comprises the following steps: S1: Dust sensor placement based on the spatial characteristics of the machine tool working area; S2: Use dust sensors to collect information on multi-point and multi-scale dust concentrations during cutting; S3: The host computer obtains the data information of each dust sensor collected in step S2; S4: Dust concentration data processing, analysis and visualization based on data fusion technology; S5: Dust concentration safety threshold setting and exceeding the limit alarm indication.

2. The method for monitoring and evaluating cutting dust in a machine tool working area according to claim 1, characterized in that: The rules for distributing dust sensors based on the spatial characteristics of the machine tool working area described in step S1 are as follows: dust sensors need to be evenly distributed on the side walls of the working area, with a certain distance between every two dust sensors, and the height of the monitoring point from the ground should be within the breathing zone of the workers; at the same time, areas where large air flows or eddies are generated should be avoided.

3. The method for monitoring and evaluating cutting dust in a machine tool working area according to claim 1, characterized in that: The dust sensor described in step S1 needs to have multiple monitoring channels and be able to simultaneously monitor dust of multiple scales, such as TSP, PM10, PM2.5, and PM1.

0. TSP, PM10, PM2.5, and PM1.0 refer to dust with aerodynamic diameters less than 100 μm, 10 μm, 2.5 μm, and 1.0 μm, respectively.

4. The method for monitoring and evaluating cutting dust in a machine tool working area according to claim 1, characterized in that: The host computer described in step S3 needs to be equipped with a data acquisition interface and software. Each dust sensor is matched through the data acquisition interface, and each group of data collected by the dust sensor is unpacked and compiled to form a data file and temporarily stored in the specified path for subsequent batch processing and analysis and evaluation; in addition, the host computer must also have a dust sensor control function, which controls the dust sensor to start or stop working through the software in the host computer, configures the calibration coefficients of different channels of the dust sensor, and monitors the working status of the dust sensor in real time, and sends a reconnection command when the dust sensor connection status is abnormal.

5. The method for monitoring and evaluating cutting dust in a machine tool working area according to claim 1, characterized in that: The specific process of dust concentration data processing and analysis based on data fusion technology described in step S4 is as follows: the data read by the host computer covers the entire process before and after the machine tool works in terms of time, and involves multi-region dust distribution characteristics represented by multi-point dust sensors in space, and includes TSP, PM10, PM2.5, PM1.0 and other dust scales in terms of scale; the host computer needs to process the obtained data in real time and in batches based on data fusion technology, and update the dust concentration change curve and distribution diagram in real time according to the spatial area and dust scale classification; further, a scientific evaluation is carried out according to the relevant dust contact level assessment indicators, so as to guide the application of dust removal equipment and the working hours of the staff.

6. The method for monitoring and evaluating cutting dust in a machine tool working area according to claim 1, characterized in that: The dust concentration safety threshold setting and excessive alarm indication described in step S5: The dust concentration safety threshold setting needs to be performed based on the results of the dust concentration data processing and analysis in step 4, and a multi-channel electromagnetic relay is used to control the LED lights and buzzer alarm components to give an alarm indication when the dust concentration exceeds the standard in any area or scale within the machine tool working area.

7. The method for monitoring and evaluating cutting dust in a machine tool working area according to claim 5, characterized in that: In step S4, the data fusion technology includes: (1) data preprocessing: standardizing and denoising the data to eliminate abnormal data and improve data quality. In addition, in order to solve the problem of packet sticking and packet loss that is prone to occur during the transmission of string signals, a special buffer processing area is established in the preprocessing software to determine the string length. When the string length does not meet the preset length requirement, the data is discarded to ensure data consistency; (2) data alignment: using the timestamp synchronization method, the host computer system time is used as the reference time to synchronize the timestamps of all dust sensor return data to ensure that they can be compared and fused under the same reference frame; (3) feature-level fusion: processing the data returned by multiple dust sensors, extracting the concentration change characteristics of dust in the time process, the distribution change characteristics in the space of the processing machine tool, and the differences in the above-mentioned spatiotemporal characteristics at different dust scales, and generating multi-scale dust concentration change curves, dust spatial distribution schematic diagrams, and dust contact level index evaluation results based on the feature-level fusion processing results.

8. A system for monitoring and evaluating cutting dust in the working area of ​​a machine tool, characterized in that: The evaluation system includes the following modules: a dust sensor module for obtaining dust concentration information in the machine tool space; The data transmission module needs to adapt to the machine tool wiring requirements and is used to transmit data to the host computer. The host computer module needs to have relevant software to realize data collection, data processing, and sensor configuration functions. The data visualization module is used to visualize the dust monitoring and evaluation results. The over-standard alarm module is used to indicate the alarm when the dust concentration exceeds the standard.

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