Method, system and medium for realizing machine tool collision protection through vibration and load

Abstract

The embodiment of the present invention discloses a method, system and medium for realizing machine tool collision protection through vibration and load, the method comprising obtaining vibration data of the moving parts of the machine tool and power data of the machine tool spindle motor, i.e., power data; fusing the vibration data and power data; judging whether the result of the fusing process is not less than a preset collision alarm boundary value; if the judgment result is yes, judging that a machine tool collision event has occurred, triggering machine tool collision protection, and controlling the machine tool to stop immediately. The technical solution provided by the embodiment of the present invention monitors the vibration data of the moving parts of the machine tool and the power data of the machine tool spindle motor, i.e., load data, in real time, comprehensively judging whether the machine tool has collided from the two dimensions of vibration and power, with high accuracy and low false alarm rate, thus improving the stability and reliability of machine tool collision protection, and being suitable for popularization and application.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of intelligent machine tools, and in particular to a method, system and medium for implementing collision protection of machine tools through vibration and load. Background Art

[0002] During the processing of current machine tools (machining centers, lathes, milling machines, turn-milling composites, grinders and some special machine tools, etc.), it is inevitable that various accidents such as misoperation, programming errors, system abnormalities, etc. will occur. These accidents will cause the processing parts of the machine tools to collide, that is, machine tool collision. Once a machine tool collision occurs, the tool may be damaged at the least, and the core components such as the workbench and spindle may be scrapped at the worst. Not only will huge maintenance costs be incurred, but the downtime for maintenance will also affect the normal production of the enterprise. Therefore, there is an urgent need for a machine tool collision protection solution to protect the machine tool processing parts from being seriously damaged. Summary of the invention

[0003] In order to solve the related technical problems, the present invention provides a method, system and medium for realizing machine tool collision protection through vibration and load, so as to solve the problems mentioned in the above background technology part.

[0004] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0005] In a first aspect, an embodiment of the present invention provides a method for implementing machine tool collision protection through vibration and load, comprising:

[0006] Obtain vibration data of the moving parts of the machine tool and power data (i.e. load data) of the machine tool spindle motor;

[0007] Performing fusion processing on the vibration data and the power data;

[0008] Determining whether the result of the fusion processing is not less than a preset collision alarm boundary value;

[0009] If the judgment result is yes, it is determined that a machine tool collision event occurs, and the machine tool collision protection is triggered, wherein the machine tool collision protection includes but is not limited to machine tool shutdown.

[0010] As an optional implementation manner, the obtaining of vibration data of a moving part of a machine tool includes:

[0011] The vibration sensor is arranged on the moving parts of the machine tool, wherein the moving parts of the machine tool include but are not limited to a spindle, a moving axis and a work table;

[0012] The vibration sensor collects the vibration signal of the moving parts of the machine tool in real time and outputs it to the vibration signal AD acquisition module;

[0013] The vibration signal AD acquisition module performs analog-to-digital conversion on the received vibration signal and sends the result to the data processing module of the control unit;

[0014] The data processing module processes the received data to obtain the required vibration data.

[0015] As an optional implementation manner, the data processing module processes the received data to obtain the required vibration data, including:

[0016] The response time of the machine tool collision protection and the period of the data processing module collecting data from the vibration signal AD acquisition module, that is, the time from the start of sampling to the end of sampling, are set to T; wherein, within the T time, the data processing module collects n groups of data, and each group of data in the n groups of data consists of vibration data in three directions of A, B, and C;

[0017] The data processing module calculates the vector and data X[n] of n sets of data acquired each time, and then pushes the vector and data into the vector and queue, wherein,

[0018]

[0019] The data processing module reads the latest n sets of vectors and data and (mn) sets of vectors and data in the historical data from the vector and queue, calculates the average value UX[n] and pushes them into the average queue in sequence;

[0020] The data processing module takes the latest n sets of vectors and data from the vector and queue, and takes the latest n sets of data from the mean queue, and calculates the first variance of the latest data

[0021]

[0022] The data processing module calculates the mean C of the latest m groups of data in the vector and queue:

[0023]

[0024] As an optional implementation, obtaining the power data of the machine tool spindle motor includes:

[0025] The current acquisition module is arranged on the power supply line of the machine tool spindle motor; the current signal of the machine tool spindle motor is collected in real time by the current acquisition module, and outputted to the current and voltage AD acquisition module;

[0026] The voltage signal of the machine tool spindle motor is collected in real time by any one of the following two methods, and outputted to the current and voltage AD collection module; wherein the two methods include: 1. collecting the voltage signal of the machine tool spindle motor in real time by the voltage collection module; 2. directly collecting the phase voltage signal or line voltage signal of the machine tool spindle motor;

[0027] The current and voltage AD acquisition module performs analog-to-digital conversion on the received current signal and voltage signal, and sends the converted data to the data processing module of the control unit;

[0028] The data processing module calculates the current value and voltage value of the machine tool spindle motor, and calculates the power data of the machine tool spindle motor according to the current value and voltage value.

[0029] As an optional implementation, the data processing module calculates the current value and voltage value of the machine tool spindle motor, and calculates the power value of the machine tool spindle motor according to the current value and voltage value, and then further includes:

[0030] The data processing module pushes the power value into a power value queue;

[0031] The data processing module reads the latest n power values ​​and (mn) power values ​​in the historical data from the power value queue, calculates the average value UY[n] and pushes them into the average value queue in sequence;

[0032] The data processing module takes the latest n power values ​​from the power value queue and the latest n means from the mean value queue, and calculates the first variance β[n] of the latest data:

[0033]

[0034] The data processing module calculates the average value D of the latest m power values ​​in the power value queue:

[0035]

[0036] As an optional implementation manner, the fusing processing of the vibration data and the power data includes:

[0037] The data processing module calculates the weight ratio of vibration data to power data in the tool machine collision protection judgment based on the mean value C of the latest m groups of data in the vector sum queue and the mean value D of the latest m power values ​​in the power value queue:

[0038] b is a constant;

[0039] The data processing module calculates the fusion status of the latest n groups of data:

[0040]

[0041] Where X[n] is the vector sum data of the latest n sets of vibration data, Y[n] is the latest n sets of power data corresponding to the vibration data, a is the weight ratio C / D, b is a constant, is the first variance of the latest n sets of vibration data, and β[n] is the first variance of the latest n sets of power data.

[0042] In a second aspect, an embodiment of the present invention provides a system for implementing machine tool collision protection through vibration and load, comprising:

[0043] An acquisition module, used for acquiring vibration data of the moving parts of the machine tool and power data of the spindle motor of the machine tool;

[0044] A fusion calculation module, used for fusing the vibration data and the power data;

[0045] A judgment module, used to determine whether the result of the fusion processing is not less than a preset collision alarm boundary value;

[0046] The execution module is used to determine that a machine tool collision event occurs when the judgment result of the judgment module is yes, and trigger the machine tool collision protection, wherein the machine tool collision protection includes but is not limited to machine tool shutdown.

[0047] As an optional implementation, the acquisition module includes:

[0048] A vibration sensor is arranged on the moving part of the machine tool, and the vibration signal of the moving part of the machine tool is collected in real time by the vibration sensor, and outputted to the vibration signal AD collection module;

[0049] The vibration signal AD acquisition module performs analog-to-digital conversion on the received vibration signal and sends it to the data processing module of the control unit;

[0050] A current acquisition module is arranged on the power supply line of the machine tool spindle motor, and is used to collect the current signal of the machine tool spindle motor in real time and output it to the current and voltage AD acquisition module;

[0051] The current and voltage AD acquisition module is used to perform analog-to-digital conversion on the received current signal and voltage signal, and send the converted data to the control unit;

[0052] A control unit, on the one hand, processes the data sent by the vibration signal AD acquisition module through the data processing module to obtain the required vibration data, and on the other hand, calculates the current value and voltage value of the machine tool spindle motor through the data processing module, and calculates the power data of the machine tool spindle motor according to the current value and voltage value;

[0053] The fusion calculation module, judgment module and execution module are all integrated in the data processing module.

[0054] As an optional implementation, the system for implementing machine tool collision protection through vibration and load also includes:

[0055] The host computer is used to configure parameters for the control unit and monitor the machine tool collision protection data in real time.

[0056] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium, in which computer execution instructions are stored. When the computer execution instructions are executed by a processor, they are used to implement the method for machine tool collision protection through vibration and load as described in any one of the first aspects.

[0057] In a fourth aspect, an embodiment of the present invention provides a computer program product, including a computer program, which, when executed by a processor, implements the method for machine tool collision protection through vibration and load as described in any one of the first aspects.

[0058] The method, system and medium for realizing machine tool collision protection through vibration and load provided by the embodiment of the present invention include obtaining vibration data of the moving parts of the machine tool and power data of the machine tool spindle motor, i.e., power data; fusing the vibration data and power data; judging whether the result of the fusing process is not less than the preset collision alarm boundary value; if the judgment result is yes, judging that a machine tool collision event has occurred, triggering the machine tool collision protection, and controlling the machine tool to stop immediately. The technical solution provided by the embodiment of the present invention monitors the vibration data of the moving parts of the machine tool and the power data of the machine tool spindle motor, i.e., load data, in real time, comprehensively judging whether the machine tool has collided from the two dimensions of vibration and power, with high accuracy and low false alarm rate, thus improving the stability and reliability of the machine tool collision protection, and being suitable for popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate and understand the technical solutions in the embodiments of the present invention, the following briefly introduces the background technology of the present invention and the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0060] Figure 1 A schematic flow chart of a method for realizing machine tool collision protection through vibration and load provided in the first embodiment of the present invention;

[0061] Figure 2A A fluctuation diagram of vibration data and power data of a machine tool during heavy cutting provided by an embodiment of the present invention;

[0062] Figure 2B A fluctuation diagram of vibration data and power data when an external object hits a machine tool housing provided by an embodiment of the present invention;

[0063] Figure 3 A schematic diagram of a system for implementing machine tool collision protection through vibration and load provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0064] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. It should also be noted that for ease of description, only the parts related to the relevant inventions are shown in the accompanying drawings. The embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0065] The present disclosure will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0066] Embodiment 1

[0067] like Figure 1 As shown, Figure 1 A schematic flow chart of a method for realizing machine tool collision protection through vibration and load provided in the first embodiment of the present invention;

[0068] In this embodiment, the method 100 for realizing machine tool collision protection through vibration and load includes:

[0069] S101. Obtain vibration data of a moving part of a machine tool and power data of a spindle motor of the machine tool; it is worth mentioning that the power data of the spindle motor of the machine tool refers to the load data of the spindle motor of the machine tool.

[0070] For example, in this embodiment, the moving parts include but are not limited to a spindle, a moving axis, and a work surface. In specific applications, the vibration data of a machine tool spindle is often obtained.

[0071] S102. Fusion processing of the vibration data and power data;

[0072] S103. Determine whether the result of the fusion processing is not less than a preset collision alarm boundary value;

[0073] Exemplarily, in this embodiment, the process of obtaining the collision alarm boundary value is as follows: the vibration data of the machine tool moving parts and the power data of the machine tool spindle motor during normal processing are obtained through experiments, and the collision alarm boundary value is obtained by multiplying the fusion result by an empirical coefficient.

[0074] S104. If the judgment result of step S103 is yes, it is determined that a machine tool collision event occurs, and the machine tool collision protection is triggered, wherein the machine tool collision protection includes but is not limited to machine tool shutdown.

[0075] The technical solution provided by the embodiment of the present invention solves the problem of only collecting vibration data of the moving parts of the machine tool and judging whether the machine tool has collided only by the vibration situation. Specifically, only collecting vibration data of the moving parts of the machine tool and judging whether the machine tool has collided only by the vibration situation has a good monitoring effect on the high-speed collision situation. However, if Figure 2A As shown in the figure, during heavy cutting, the load data of the machine tool is often large, while the vibration data often does not fluctuate significantly. If the vibration data is used alone to determine whether a collision has occurred, it will easily lead to misjudgment. In addition, Figure 2B As shown, during the normal processing of the machine tool, if something from the outside hits the machine tool shell, it may sometimes be mistakenly judged as a machine tool collision. The method for realizing machine tool collision protection through vibration and load provided by the embodiment of the present invention monitors the vibration data of the moving parts of the machine tool and the power data of the machine tool spindle motor, i.e., load data, in real time, comprehensively judges whether the machine tool has collided from the two dimensions of vibration and power, and triggers the machine tool collision protection when it is determined that the machine tool has collided, with high accuracy and low false alarm rate, thus improving the stability and reliability of the machine tool collision protection.

[0076] Embodiment 2

[0077] The method for realizing machine tool collision protection through vibration and load in this embodiment includes:

[0078] S201. Obtain vibration data of a moving part of a machine tool and power data of a spindle motor of the machine tool; it is worth mentioning that the power data of the spindle motor of the machine tool refers to the load data of the spindle motor of the machine tool.

[0079] S202. Fusion processing is performed on the vibration data and the power data;

[0080] S203. Determine whether the result of the fusion processing is not less than a preset collision alarm boundary value;

[0081] Exemplarily, in this embodiment, the process of obtaining the collision alarm boundary value is as follows: the vibration data of the machine tool moving parts and the power data of the machine tool spindle motor during normal processing are obtained through experiments, and the collision alarm boundary value is obtained by multiplying the fusion result by an empirical coefficient.

[0082] S204. If the judgment result of step S203 is yes, it is determined that a machine tool collision event occurs, and the machine tool collision protection is triggered, wherein the machine tool collision protection includes but is not limited to machine tool shutdown.

[0083] Exemplarily, in step 201 of this embodiment, the vibration data of the moving parts of the machine tool are obtained, which specifically includes:

[0084] S20111. The vibration sensor is disposed on the moving part of the machine tool;

[0085] In this embodiment, the installation position of the vibration sensor needs to be determined according to the situation of the machine tool, generally based on the moving parts of the machine tool but not limited to the moving parts of the machine tool. Different machine tools will be installed in different positions. For example, in this embodiment, the moving parts include but are not limited to the spindle, the moving axis and the work table. In specific applications, the spindle is the most common.

[0086] Exemplarily, the vibration sensor in this embodiment uses a uniaxial sensor or a triaxial sensor, preferably a triaxial acceleration sensor, and the acceleration range of the triaxial acceleration sensor is flexibly selected according to the specific application scenario.

[0087] S20112. The vibration sensor collects the vibration signal of the moving parts of the machine tool in real time and outputs it to the vibration signal AD acquisition module;

[0088] S20113. The vibration signal AD acquisition module performs analog-to-digital conversion on the received vibration signal and sends it to the data processing module of the control unit;

[0089] Exemplarily, in this embodiment, according to the requirements of the machine tool collision protection response speed in different scenarios, a vibration signal AD acquisition module with the acquisition frequency and acquisition accuracy that meet the requirements is selected. Exemplarily, in this embodiment, the vibration signal AD acquisition module converts the received vibration signal analog-to-digital into vibration data, and sends a large amount of vibration data to the data processing module of the control unit every second. For example, in one application, the vibration signal AD acquisition module pushes 3600 groups of data per second to the data processing module of the control unit, where a group of data refers to a group of vibration data. Exemplarily, in this embodiment, the AD acquisition module can choose to send data to the control unit through the SPI interface, but is not limited to this data communication method.

[0090] S20114. The data processing module processes the received data to obtain the required vibration data, specifically including:

[0091] S20115. The response time of the machine tool collision protection and the period of the data processing module collecting data from the vibration signal AD acquisition module, i.e., the time from the start of sampling to the end of sampling, are set to T; wherein, within the T time, the data processing module collects n groups of data, each of the n groups of data consists of vibration data in three directions of A, B, and C; in this embodiment, n is a positive integer; in this embodiment, the vibration data in the three directions of A, B, and C refer to the vibration data in the three directions of x, y, and z, respectively;

[0092] S20116. The data processing module calculates the vector and data X[n] of the n sets of data acquired each time, and then pushes the vector and data into the vector and queue, wherein:

[0093]

[0094] In this embodiment, the vibration signal AD acquisition module converts the received vibration signal analog-to-digital into vibration data, and sends a large amount of vibration data to the data processing module of the control unit every second. The data processing module obtains n groups of data each time, calculates the vector and data X[n] of the n groups of data obtained each time, and then pushes the vector and data into the vector and queue. Therefore, new vectors and data will always be added to the vector and queue during operation.

[0095] S20117. The data processing module reads the latest n sets of vectors and data and (mn) sets of vectors and data in the historical data from the vector and queue, calculates the average value UX[n] and pushes them into the average queue in sequence;

[0096] It should be noted that the latest n sets of vectors and data here refer to the n sets of vectors and data pushed into the vector and queue within the latest time T. In this embodiment, m is a positive integer greater than n. In this embodiment, n is preferably 4 and m is 64.

[0097] S20118. The data processing module takes the latest n sets of vectors and data from the vector and queue, and takes the latest n sets of data from the mean queue, and calculates the first variance of the latest data

[0098]

[0099] S20119. The data processing module calculates the mean C of the latest m groups of data in the vector and queue:

[0100]

[0101] Exemplarily, in step 201 of this embodiment, obtaining the power data of the moving parts of the machine tool specifically includes:

[0102] S20121. The current acquisition module is set on the power supply line of the machine tool spindle motor; the current acquisition module collects the current signal of the machine tool spindle motor in real time and outputs it to the current and voltage AD acquisition module;

[0103] For example, in a specific application, the current acquisition module is not limited to being set on the power supply line of the machine tool spindle motor, that is, the power line of the machine tool spindle motor. Depending on the monitoring scenario and other requirements, the current acquisition module can also be set on the processing axis of the machine tool, such as a servo axis. This embodiment takes the machine tool spindle as an example. Applications installed in other locations are similar to those installed on the spindle, and will not be described one by one.

[0104] In this embodiment, the current acquisition module is used to collect the current signal of the machine tool spindle motor in real time, and output it to the current and voltage AD acquisition module. Exemplarily, the current acquisition module is preferably a Hall current sensor. According to the requirements of the machine tool collision protection response speed in different scenarios, it is necessary to select a Hall current sensor with corresponding accuracy. Normally, a Hall current sensor with an accuracy of not less than 5 / 1000 is used. It is worth mentioning that in this embodiment, the Hall current sensor is installed on the power supply line of the machine tool spindle motor. The installation is simple, convenient and easy to operate, and does not change the existing state of the machine tool. The current is collected as a monitoring object with high real-time performance, and the current has a good AC frequency characteristic and is not easily interfered by external signals. After a large number of comparative analysis experiments, it is determined that the current is very suitable for the machine tool collision protection solution.

[0105] Exemplarily, the voltage signal of the machine tool spindle motor is collected in real time by any of the following two methods, and output to the current and voltage AD acquisition module; wherein, the two methods include: 1. The voltage signal of the machine tool spindle motor is collected in real time by the voltage acquisition module; wherein, the voltage acquisition module is preferably a Hall current sensor. According to the requirements of the machine tool collision protection response speed in different scenarios, it is necessary to select a Hall current sensor with corresponding accuracy; 2. Directly collect the phase voltage signal or line voltage signal of the machine tool spindle motor.

[0106] Exemplarily, in this embodiment, it is preferred to directly acquire the phase voltage signal or line voltage signal of the machine tool spindle motor to obtain the voltage signal of the machine tool spindle motor.

[0107] S20122. The current and voltage AD acquisition module performs analog-to-digital conversion on the received current signal and voltage signal, and sends the converted data to the data processing module of the control unit;

[0108] For example, in this embodiment, according to the requirements of the machine tool collision protection response speed in different scenarios, a current and voltage AD acquisition module with the required acquisition frequency and acquisition accuracy is selected. For example, in this embodiment, the current and voltage AD acquisition module converts the received current signal and voltage signal (i.e., three-phase current signal and three-phase voltage signal) into three-phase current data and three-phase voltage data, and sends a large amount of three-phase current data and three-phase voltage data to the control unit every second. For example, in this embodiment, the current and voltage AD acquisition module can choose to send data to the control unit through the SPI interface, but is not limited to this data communication method.

[0109] S20123. The data processing module processes the received current data and voltage data to obtain the current value and voltage value of the machine tool spindle motor, and calculates the power value of the machine tool spindle motor according to the current value and voltage value;

[0110] Exemplarily, in this embodiment, the data processing module performs filtering and precise bandpass filtering on the collected data in sequence to obtain the current value and voltage value of the machine tool spindle motor. An implementation scheme is now selected and described as follows:

[0111] The response time of the machine tool collision protection and the period of the control unit collecting data from the current and voltage AD acquisition module, that is, the time from the start of sampling to the end of sampling each time, are set to T; wherein, within the T time, the control unit collects n groups of data, and each of the n groups of data consists of a group of three-phase current data and a group of three-phase voltage data; wherein n is a positive integer, and the preferred empirical value is 4.

[0112] The control unit performs FFT transformation on the collected M groups of data each time to obtain FFT frequency domain data of the M groups of data, queries the data with the largest frequency domain amplitude in the FFT frequency domain data of the M groups of data and uses it as the core frequency FH ​​of the group of data; wherein, the M groups of data are composed of the n groups of data most recently collected by the control unit and (Mn) groups of historical data; it is worth mentioning that M is any positive integer that meets the FFT requirement for the number of data, and the preferred empirical value is 1024.

[0113] The control unit retains the amplitude and symmetry (M-FH) of the positive and negative setting values ​​of the core frequency FH ​​for the FFT frequency domain data of the M groups of data, and sets other frequency domain data to zero, thereby completing precise bandpass filtering; illustratively, in this embodiment, the positive and negative setting values ​​need to be determined based on actual conditions, and the preferred empirical value is 10.

[0114] The control unit performs an inverse FFT operation on the frequency domain data after the precise bandpass filtering to obtain M groups of time domain data, and extracts the first n groups of data from the M groups of time domain data, wherein the first n groups of data are the actual three-phase current values ​​I of the spindle motor of the machine tool within the time T.a , I b , I c And the three-phase voltage value U a , U a , U c .

[0115] The control unit calculates the actual three-phase current value I of the machine tool spindle motor within the time T. a , I b , I c And the three-phase voltage value U a , U a , U c Perform integral operation to calculate the instantaneous power value P of the machine tool spindle motor:

[0116]

[0117] The instantaneous power value P is smoothed by formula (1) and formula (2):

[0118]

[0119]

[0120] Wherein, P[N] refers to the power data calculated each time in step S3014, and N refers to the number of data to be smoothed. By moving smoothing, interference and abnormal burr data can be effectively removed, and the accuracy of machine tool collision protection judgment can be improved.

[0121] Exemplarily, in this embodiment, the data processing module calculates the current value and voltage value of the machine tool spindle motor, and calculates the power value of the machine tool spindle motor according to the current value and voltage value, and then further includes:

[0122] S20124. The data processing module pushes the power value into a power value queue;

[0123] Exemplarily, in this embodiment, in order to achieve synchronization of vibration data and power data, in this embodiment, the vibration signal AD acquisition module and the current and voltage AD acquisition module push the same amount and frequency of data to the control unit within the same time. For example, in one application, the vibration signal AD acquisition module pushes 3600 groups of data per second to the data processing module of the control unit, and the current and voltage AD acquisition module also pushes 3600 groups of data per second to the data processing module of the control unit.

[0124] S20125. The data processing module reads the latest n power values ​​and (mn) power values ​​in the historical data from the power value queue, calculates the average value UY[n] and pushes them into the average value queue in sequence;

[0125] Here, the latest n power values ​​refer to the n power values ​​pushed into the power value queue within the latest time T. In this embodiment, m is a positive integer greater than n. In this embodiment, n is preferably 4 and m is preferably 64.

[0126] S20126. The data processing module takes the latest n power values ​​from the power value queue, and takes the latest n means from the mean value queue, and calculates the first variance β[n] of the latest data:

[0127]

[0128] S20127. The data processing module calculates the average value D of the latest m power values ​​in the power value queue:

[0129]

[0130] In step S202 of this embodiment, the vibration data and the power data are fused, which specifically includes:

[0131] S2021. The data processing module calculates the weight ratio of vibration data to power data in the machine tool collision protection judgment according to the mean value C of the latest m groups of data in the vector sum queue and the mean value D of the latest m power values ​​in the power value queue:

[0132] b is a constant;

[0133] S2022. The data processing module calculates the fusion status of the latest n groups of data:

[0134]

[0135] Where X[n] is the vector sum data of the latest n sets of vibration data, Y[n] is the latest n sets of power data corresponding to the vibration data, a is the weight ratio C / D, b is a constant, is the first variance of the latest n sets of vibration data, and β[n] is the first variance of the latest n sets of power data.

[0136] In the step S203 of the present embodiment, judging whether the result of the fusion processing is not less than the preset collision alarm boundary value specifically includes: judging whether the result of the fusion processing within the time T is not less than the preset collision alarm boundary value.

[0137] In this embodiment, the collision alarm boundary value is obtained by experimenting to obtain the fusion result of the vibration data of the machine tool moving parts and the power data of the machine tool spindle motor during normal processing, and the collision alarm boundary value is obtained by multiplying the fusion result by an empirical coefficient. The preferred empirical coefficient in practical applications is 1.3. Therefore, it is necessary to obtain the fusion result of the vibration data of the machine tool moving parts and the power data of the machine tool spindle motor during normal processing of the machine tool in advance through experiments, and then determine an empirical coefficient to calculate the collision protection boundary value, that is, the collision alarm boundary value, to maximize the accuracy of the collision protection response, and reduce or even avoid the false triggering of the collision protection. Specifically, in this embodiment, after the vibration sensor and the current acquisition module are installed, the machine tool is allowed to run normally for a period of time. The control unit collects statistics on the data during the operation. The running time can be set by the host computer. After the data statistics are completed, the control unit sends the upper and lower boundary values ​​of the statistical data to the host computer, so that the data boundary values ​​during the normal operation of the machine tool can be known, and the boundary values ​​of the fusion results of the vibration data of the moving parts of the machine tool and the power data of the spindle motor of the machine tool during normal processing are counted. In the actual monitoring process, the boundary value of the fusion result is multiplied by an empirical coefficient, which is the collision alarm boundary value. The coefficient value is generally greater than 1. The smaller the coefficient, the more sensitive the alarm.

[0138] It is worth mentioning that in the present embodiment, the feed rate of the machine tool spindle is different, and the corresponding collision alarm boundary value is different. Therefore, it is necessary to obtain the vibration data of the machine tool moving parts and the power data of the machine tool spindle motor corresponding to each feed rate scenario of the machine tool spindle through experiments in advance, that is, the absolute alarm boundary in each scenario, and then determine an empirical coefficient to calculate the collision alarm boundary value in each feed rate scenario, that is, the collision alarm boundary value in each scenario, to ensure the accuracy of the collision protection response in each feed rate scenario, and reduce or even avoid the false triggering of the collision protection in each feed rate scenario. At the beginning of the machine tool collision protection monitoring, the feed rate of the current machine tool spindle is obtained in real time, and the corresponding collision alarm boundary value under the current feed rate scenario is retrieved for machine tool collision protection judgment, wherein the method of obtaining the feed rate of the current machine tool spindle in real time is preferably but not limited to any one of the following two methods: 1. The control unit obtains the state of the machine tool spindle in real time by communicating with the machine tool controller, for example, the IO / Ethernet / 232 and other communication interfaces of the control unit communicate with the machine tool controller; 2. Modify the T diagram, wherein the T diagram is the running program in the machine tool controller. Some machine tools do not provide the points or addresses of the machine tool working mode, and the output is performed by modifying the machine tool program.

[0139] In this embodiment, the collision event of the machine tool generally occurs during the movement of the moving parts, and the collision will not occur when the spindle stops rotating. Therefore, in this embodiment, the state of the machine tool spindle is monitored in real time. When the machine tool spindle is monitored to start rotating, the control unit works, starts the machine tool collision protection scheme proposed in this embodiment, and the machine tool implements the collision monitoring work; when the machine tool spindle is monitored to stop rotating, the control unit stops working, closes the machine tool collision protection scheme proposed in this embodiment, and the machine tool collision monitoring stops. Exemplarily, in this embodiment, the state of the machine tool spindle is preferably but not limited to any of the following two methods: 1. The control unit obtains the state of the machine tool spindle in real time by communicating with the machine tool controller, for example, the control unit's IO / Ethernet / 232 and other communication interfaces communicate with the machine tool controller; 2. Modify the T diagram, where the T diagram is the running program in the machine tool controller. Some machine tools do not provide the point or address of the machine tool working mode, and the output is performed by modifying the machine tool program.

[0140] Exemplarily, in step S204 described in this embodiment, once it is determined that a machine tool collision event has occurred, the machine tool collision protection is triggered. In this embodiment, the machine tool collision protection includes but is not limited to machine tool shutdown. When the control unit determines that a machine tool collision event has occurred, the preferred method of this embodiment is that the control unit immediately feeds back the result of the machine tool collision event to the machine tool end through the alarm feedback module. The machine tool end will realize the machine tool shutdown within the collision protection response time (such as 1ms), and can simultaneously trigger a voice alarm, a red light alarm, a voice alarm, etc., and can also display the alarm content on the machine tool end.

[0141] Exemplarily, in this embodiment, the alarm feedback module realizes data communication with the machine tool end through interfaces such as but not limited to IO / Ethernet / RS232 / RS422 / PROFIBUS / PROFINET / ETHERCAT. Exemplarily, in this embodiment, the alarm trigger signal is preferably incorporated into the emergency stop signal of the machine tool through a dry contact. When a machine tool collision occurs, the alarm is triggered and the machine tool stops immediately. Exemplarily, in this embodiment, by modifying the machine tool T diagram, when the alarm information is input into the machine tool end, the alarm content will be displayed on the machine tool end. Among them, the T diagram is the running program in the machine tool controller. Some machine tools do not provide the points or addresses of the machine tool working mode, and the output is performed by modifying the machine tool program. Exemplarily, in this embodiment, the types of alarms can also be expanded at the machine tool end and the machine tool collision protection system end, such as SMS alarms, voice alarms, PLC alarms, etc., to notify relevant personnel of the occurrence of a machine tool collision event as soon as possible.

[0142] The technical solution provided by the embodiment of the present invention solves the problem of only collecting vibration data of the moving parts of the machine tool and judging whether the machine tool has collided only by the vibration situation. Specifically, only collecting vibration data of the moving parts of the machine tool and judging whether the machine tool has collided only by the vibration situation has a good monitoring effect on the high-speed collision situation. However, if Figure 2A As shown in the figure, during heavy cutting, the load data of the machine tool is often large, while the vibration data often does not fluctuate significantly. If the vibration data is used alone to determine whether a collision has occurred, it will easily lead to misjudgment. In addition, Figure 2B As shown, during the normal processing of the machine tool, if something from the outside hits the machine tool shell, it may sometimes be mistakenly judged as a machine tool collision. The method for realizing machine tool collision protection through vibration and load provided by the embodiment of the present invention monitors the vibration data of the moving parts of the machine tool and the power data of the machine tool spindle motor, i.e., load data, in real time, comprehensively judges whether the machine tool has collided from the two dimensions of vibration and power, and triggers the machine tool collision protection when it is determined that the machine tool has collided, with high accuracy and low false alarm rate, thus improving the stability and reliability of the machine tool collision protection.

[0143] Embodiment 3

[0144] like Figure 3 As shown, Figure 3 A schematic diagram of the structure of a system for implementing machine tool collision protection through vibration and load provided in Embodiment 3 of the present invention;

[0145] This embodiment provides a system for machine tool collision protection through vibration and load, and the system adopts the method for machine tool collision protection through vibration and load described in any one of the above-mentioned embodiments 1 or 2. Exemplarily, the system for machine tool collision protection through vibration and load specifically includes:

[0146] An acquisition module, used for acquiring vibration data of the moving parts of the machine tool and power data of the spindle motor of the machine tool;

[0147] A fusion calculation module, used for fusing the vibration data and the power data;

[0148] A judgment module, used to determine whether the result of the fusion processing is not less than a preset collision alarm boundary value;

[0149] The execution module is used to determine that a machine tool collision event occurs when the judgment result of the judgment module is yes, and trigger the machine tool collision protection, wherein the machine tool collision protection includes but is not limited to machine tool shutdown.

[0150] Exemplarily, in this embodiment, the acquisition module includes:

[0151] A vibration sensor is arranged on the moving part of the machine tool, and the vibration signal of the moving part of the machine tool is collected in real time by the vibration sensor, and outputted to the vibration signal AD collection module;

[0152] In this embodiment, the installation position of the vibration sensor needs to be determined according to the situation of the machine tool. Generally, the moving parts of the machine tool are mainly used, but not limited to the moving parts of the machine tool. Different machine tools will be installed in different positions. For example, in this embodiment, the moving parts include but are not limited to the spindle, the motion axis and the work table. In specific applications, the spindle is the most common. For example, in this embodiment, the vibration sensor uses a single-axis sensor or a three-axis sensor, preferably a three-axis acceleration sensor, and the acceleration range of the three-axis acceleration sensor is flexibly selected according to the specific application scenario.

[0153] The vibration signal AD acquisition module performs analog-to-digital conversion on the received vibration signal and sends it to the data processing module of the control unit;

[0154] Exemplarily, in this embodiment, according to the requirements of the machine tool collision protection response speed in different scenarios, a vibration signal AD acquisition module with the acquisition frequency and acquisition accuracy that meet the requirements is selected. Exemplarily, in this embodiment, the vibration signal AD acquisition module converts the received vibration signal analog-to-digital into vibration data, and sends a large amount of vibration data to the data processing module of the control unit every second. For example, in one application, the vibration signal AD acquisition module pushes 3600 groups of data per second to the data processing module of the control unit, where a group of data refers to a group of vibration data. Exemplarily, in this embodiment, the AD acquisition module can choose to send data to the control unit through the SPI interface, but is not limited to this data communication method.

[0155] A current acquisition module is arranged on the power supply line of the machine tool spindle motor, and is used to collect the current signal of the machine tool spindle motor in real time and output it to the current and voltage AD acquisition module;

[0156] For example, in a specific application, the current acquisition module is not limited to being set on the power supply line of the machine tool spindle motor, that is, the power line of the machine tool spindle motor. Depending on the monitoring scenario and other requirements, the current acquisition module can also be set on the processing axis of the machine tool, such as a servo axis. This embodiment takes the machine tool spindle as an example. Applications installed in other locations are similar to those installed on the spindle, and will not be described one by one.

[0157] In this embodiment, the current acquisition module is used to collect the current signal of the machine tool spindle motor in real time, and output it to the current and voltage AD acquisition module. Exemplarily, the current acquisition module is preferably a Hall current sensor. According to the requirements of the machine tool collision protection response speed in different scenarios, it is necessary to select a Hall current sensor with corresponding accuracy. Normally, a Hall current sensor with an accuracy of not less than 5 / 1000 is used. It is worth mentioning that in this embodiment, the Hall current sensor is installed on the power supply line of the machine tool spindle motor. The installation is simple, convenient and easy to operate, and does not change the existing state of the machine tool. The current is collected as a monitoring object with high real-time performance, and the current has a good AC frequency characteristic and is not easily interfered by external signals. After a large number of comparative analysis experiments, it is determined that the current is very suitable for the machine tool collision protection solution.

[0158] Exemplarily, the voltage signal of the machine tool spindle motor is collected in real time by any of the following two methods, and output to the current and voltage AD acquisition module; wherein, the two methods include: 1. The voltage signal of the machine tool spindle motor is collected in real time by the voltage acquisition module; wherein, the voltage acquisition module is preferably a Hall current sensor. According to the requirements of the machine tool collision protection response speed in different scenarios, it is necessary to select a Hall current sensor with corresponding accuracy; 2. Directly collect the phase voltage signal or line voltage signal of the machine tool spindle motor.

[0159] Exemplarily, in this embodiment, it is preferred to directly acquire the phase voltage signal or line voltage signal of the machine tool spindle motor to obtain the voltage signal of the machine tool spindle motor.

[0160] The current and voltage AD acquisition module is used to perform analog-to-digital conversion on the received current signal and voltage signal, and send the converted data to the control unit;

[0161] For example, in this embodiment, according to the requirements of the machine tool collision protection response speed in different scenarios, a current and voltage AD acquisition module with the required acquisition frequency and acquisition accuracy is selected. For example, in this embodiment, the current and voltage AD acquisition module converts the received current signal and voltage signal (i.e., three-phase current signal and three-phase voltage signal) into three-phase current data and three-phase voltage data, and sends a large amount of three-phase current data and three-phase voltage data to the control unit every second. For example, in this embodiment, the current and voltage AD acquisition module can choose to send data to the control unit through the SPI interface, but is not limited to this data communication method.

[0162] A control unit, on the one hand, processes the data sent by the vibration signal AD acquisition module through the data processing module to obtain the required vibration data, and on the other hand, calculates the current value and voltage value of the machine tool spindle motor through the data processing module, and calculates the power data of the machine tool spindle motor according to the current value and voltage value;

[0163] Exemplarily, the fusion calculation module, judgment module and execution module are all integrated in the data processing module.

[0164] Exemplarily, in this embodiment, the control unit further includes an alarm feedback module. When the control unit determines that a machine tool collision event occurs, the preferred method of this embodiment is that the control unit immediately feeds back the result of the machine tool collision event to the machine tool end through the alarm feedback module, and the machine tool end will realize the machine tool shutdown within the collision protection response time (such as 1ms), and can simultaneously trigger the voice control alarm, red light alarm, voice alarm, etc., and can also display the alarm content on the machine tool end. Exemplarily, in this embodiment, the alarm feedback module realizes data communication with the machine tool end through but not limited to IO / Ethernet / RS232 / RS422 / PROFIBUS / PROFINET / ETHERCAT and other interfaces. Exemplarily, in this embodiment, the alarm trigger signal is preferably incorporated into the emergency stop signal of the machine tool through a dry contact, and a machine tool collision event occurs, the alarm is triggered, and the machine tool stops immediately. Exemplarily, in this embodiment, by modifying the machine tool T diagram, after the alarm information is input into the machine tool end, the alarm content will be displayed on the machine tool end. Among them, the T diagram is the running program in the machine tool controller. Some machine tools do not provide the points or addresses of the machine tool working mode, and the output is performed by modifying the machine tool program. For example, in this embodiment, the alarm type can also be expanded on the machine tool side and the machine tool collision protection system side, such as SMS alarm, voice alarm, PLC alarm, etc., to notify relevant personnel of the machine tool collision incident as soon as possible.

[0165] Exemplarily, in this embodiment, a host computer is also provided, and the host computer communicates with the control unit, and is used to configure parameters for the control unit, and monitor the machine tool collision protection data in real time. Exemplarily, in this embodiment, the configuration parameters include but are not limited to the filtering parameters of vibration data, the boundary parameter setting of vibration data, the filtering parameters of power data, the alarm boundary parameters of power data, current monitoring, power monitoring option parameters, alarm type setting (PLC alarm, emergency stop alarm, three-color light alarm, voice alarm, SMS alarm, etc.), alarm duration setting (holding time after alarm triggering). The real-time monitoring of machine tool collision protection data includes but is not limited to the current current and voltage real-time data, vibration real-time data, alarm status, historical alarm records, etc. Exemplarily, in this embodiment, the host computer includes but is not limited to mobile phones, tablets or other smart terminals.

[0166] The system for machine tool collision protection through vibration and load provided by the embodiment of the present invention monitors the vibration data of the machine tool moving parts and the power data of the machine tool spindle motor, i.e., load data, in real time, and comprehensively judges whether the machine tool has a collision from the two dimensions of vibration and power. When it is determined that a machine tool collision has occurred, the machine tool collision protection is triggered, with high accuracy and low false alarm rate, thereby improving the stability and reliability of the machine tool collision protection, and is easy and quick to install, making it suitable for popularization and application.

[0167] Embodiment 4

[0168] The present embodiment provides a computer-readable storage medium, which may include: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, and other media that can store program codes. Specifically, the computer-readable storage medium stores computer execution instructions, and when the computer execution instructions are executed by the processor, they are used to implement the machine tool collision protection through vibration and load as described in any of the above-mentioned embodiments 1 and 2.

[0169] Embodiment 5

[0170] This embodiment provides a computer program product, including a computer program. When the computer program is executed by a processor, the method for implementing machine tool collision protection through vibration and load as described in any one of the above-mentioned embodiments 1 and 2 is implemented.

[0171] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the claims of the present application.

[0172] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

[0173] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for realizing machine tool collision protection through vibration and load, characterized in that: include: Obtain vibration data of the moving parts of the machine tool and power data (i.e. load data) of the machine tool spindle motor; Performing fusion processing on the vibration data and the power data; Determining whether the result of the fusion processing is not less than a preset collision alarm boundary value; If the judgment result is yes, it is determined that a machine tool collision event occurs, and the machine tool collision protection is triggered, wherein the machine tool collision protection includes but is not limited to machine tool shutdown; Wherein, the obtaining of vibration data of the moving parts of the machine tool includes: The vibration sensor is arranged on the moving parts of the machine tool, wherein the moving parts of the machine tool include but are not limited to a spindle, a moving axis and a work table; The vibration sensor collects the vibration signal of the moving parts of the machine tool in real time and outputs it to the vibration signal AD acquisition module; The vibration signal AD acquisition module performs analog-to-digital conversion on the received vibration signal and sends the result to the data processing module of the control unit; The data processing module processes the received data to obtain the required vibration data; The data processing module processes the received data to obtain the required vibration data, including: The response time of the machine tool collision protection and the period of the data processing module collecting data from the vibration signal AD acquisition module, that is, the time from the start of sampling to the end of sampling, are set to T; wherein, within the T time, the data processing module collects n groups of data, and each group of data in the n groups of data consists of vibration data in three directions of A, B, and C; The data processing module calculates the vector and data X[n] of n sets of data acquired each time, and then pushes the vector and data into the vector and queue, wherein, The data processing module reads the latest n sets of vectors and data and (mn) sets of vectors and data in the historical data from the vector and queue, calculates the average value UX[n] and pushes them into the average queue in sequence; The data processing module takes the latest n sets of vectors and data from the vector and queue, and takes the latest n sets of data from the mean queue, and calculates the first variance of the latest data : The data processing module calculates the mean C of the latest m groups of data in the vector and queue: The data processing module calculates the current value and voltage value of the machine tool spindle motor, and calculates the power value of the machine tool spindle motor according to the current value and voltage value, and then further includes: The data processing module pushes the power value into a power value queue; The data processing module reads the latest n power values ​​and (mn) power values ​​in the historical data from the power value queue, calculates the average value UY[n] and pushes them into the average value queue in sequence; The data processing module takes the latest n power values ​​from the power value queue and the latest n means from the mean value queue, and calculates the first variance β[n] of the latest data: The data processing module calculates the average value D of the latest m power values ​​in the power value queue: The fusing of the vibration data and the power data comprises: The data processing module calculates the mean C of the latest m groups of data in the vector and queue and the power value in the queue. The mean value D of the new m power values ​​is used to calculate the weight ratio of vibration data to power data in the judgment of collision protection of the machine tool: b is a constant; The data processing module calculates the fusion status of the latest n groups of data: Where X[n] is the vector sum data of the latest n sets of vibration data, Y[n] is the latest n sets of power data corresponding to the vibration data, a is the weight ratio C / D, b is a constant, is the first variance of the latest n sets of vibration data, and β[n] is the first variance of the latest n sets of power data.

2. The method for realizing machine tool collision protection through vibration and load according to claim 1, characterized in that: Obtain the power data of the machine tool spindle motor, including: The current acquisition module is arranged on the power supply line of the machine tool spindle motor; the current signal of the machine tool spindle motor is collected in real time by the current acquisition module, and outputted to the current and voltage AD acquisition module; The voltage signal of the machine tool spindle motor is collected in real time by any one of the following two methods, and outputted to the current and voltage AD collection module; wherein the two methods include:

1. collecting the voltage signal of the machine tool spindle motor in real time by the voltage collection module; 2. directly collecting the phase voltage signal or line voltage signal of the machine tool spindle motor; The current and voltage AD acquisition module performs analog-to-digital conversion on the received current signal and voltage signal, and sends the converted data to the data processing module of the control unit; The data processing module calculates the current value and voltage value of the machine tool spindle motor, and calculates the power data of the machine tool spindle motor according to the current value and voltage value.

3. A system for protecting machine tools from collisions by vibration and load, characterized in that: The system adopts the method for realizing machine tool collision protection through vibration and load as described in claim 1, comprising: An acquisition module, used for acquiring vibration data of the moving parts of the machine tool and power data of the spindle motor of the machine tool; A fusion calculation module, used for fusing the vibration data and the power data; A judgment module, used to determine whether the result of the fusion processing is not less than a preset collision alarm boundary value; An execution module, configured to determine that a machine tool collision event occurs and trigger machine tool collision protection when a judgment result of the judgment module is yes, wherein the machine tool collision protection includes but is not limited to machine tool shutdown; Wherein, the acquisition module includes: A vibration sensor is arranged on the moving part of the machine tool, and the vibration signal of the moving part of the machine tool is collected in real time by the vibration sensor, and outputted to the vibration signal AD collection module; The vibration signal AD acquisition module performs analog-to-digital conversion on the received vibration signal and sends it to the data processing module of the control unit; A current acquisition module is arranged on the power supply line of the machine tool spindle motor, and is used to collect the current signal of the machine tool spindle motor in real time and output it to the current and voltage AD acquisition module; The current and voltage AD acquisition module is used to perform analog-to-digital conversion on the received current signal and voltage signal, and send the converted data to the control unit; A control unit, on the one hand, processes the data sent by the vibration signal AD acquisition module through the data processing module to obtain the required vibration data, and on the other hand, calculates the current value and voltage value of the machine tool spindle motor through the data processing module, and calculates the power data of the machine tool spindle motor according to the current value and voltage value; The fusion calculation module, judgment module and execution module are all integrated in the data processing module.

4. The system for protecting machine tools from collision by vibration and load according to claim 3, characterized in that: The system for realizing machine tool collision protection through vibration and load also includes: The host computer is used to configure parameters for the control unit and monitor the machine tool collision protection data in real time.

5. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method for machine tool collision protection through vibration and load as described in any one of claims 1 or 2.

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