Fixture tool operation state real-time monitoring system based on Internet of Things

Abstract

The invention relates to the technical field of data processing, in particular to a clamp tool running state real-time monitoring system based on the Internet of Things, the system comprises a processor and a memory, and the processor executes a computer program of the memory to realize the following steps: collecting at least two vibration signal sequences; for any group of vibration signal sequences, acquiring a target signal at the current sampling moment, and acquiring a state score and a fusion weight of the target signal according to fluctuation characteristics of any group of vibration signal sequences, vibration signal types of any group of vibration signal sequences and vibration signal differences between the vibration signal sequences; and according to the state score and the fusion weight of the target signal in each group of vibration signal sequences, obtaining the overall state score of the clamp at the current sampling moment, and judging the operation state of the clamp at the current sampling moment. According to the invention, the comprehensive monitoring of the clamp is realized, so that the judgment of the operation state of the clamp is more accurate.

Description

Technical Field

[0001] This invention relates to the field of data processing technology, and in particular to a real-time monitoring system for the operating status of fixtures and tooling based on the Internet of Things. Background Art

[0002] Fixtures play a wide and vital role in industrial production, not only improving production efficiency and machining accuracy but also ensuring the consistency and stability of product quality. Traditional fixture maintenance often relies on post-failure repair, which is not only inefficient but can also lead to production interruptions and increased maintenance costs. Therefore, real-time monitoring of fixtures is necessary to prevent malfunctions from occurring.

[0003] Traditional methods utilize IoT technology to collect real-time vibration data of the fixture through sensors and data acquisition modules. By monitoring and issuing early warnings of vibration data during fixture operation, potential malfunctions can be detected promptly, allowing for preventative measures to avoid failures. However, traditional methods typically use a single sensor to collect vibration data at the connection point between the fixture and the workpiece, neglecting the influence of vibration data from other areas. Due to the complex structure of robotic arms, a single sensor cannot comprehensively reflect their vibration state, potentially leading to inaccurate monitoring results and production malfunctions.

[0004] Therefore, how to comprehensively monitor the fixtures and improve the accuracy of monitoring has become an urgent problem to be solved. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide an IoT-based real-time monitoring system for the operating status of fixtures and tooling to solve the problem of how to comprehensively monitor fixtures and improve the accuracy of monitoring.

[0006] This invention provides a real-time monitoring system for the operating status of a fixture based on the Internet of Things (IoT), including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the following method: During the operation of the fixture, at least two vibration signal sequences of each part to be tested are collected at the current sampling time to obtain all vibration signal sequences of a preset number of parts to be tested; For any set of vibration signal sequences, the vibration signal at the current sampling time in the set of vibration signal sequences is recorded as the target signal. Based on the fluctuation characteristics of the set of vibration signal sequences, the outlier value of the target signal is obtained. Based on the vibration signal type of the set of vibration signal sequences and the difference in vibration signals between each part to be detected at the current sampling time and the vibration signal type of the set of vibration signal sequences, the state consistency index of the target signal is obtained. Based on the outliers and state consistency index of the target signal, obtain the state score of the target signal; based on the fluctuation characteristics of any set of vibration signal sequences, obtain the fusion weight of the target signal. The state score and fusion weight of the target signal in each vibration signal sequence are obtained. Based on the state score and fusion weight of the target signal in each vibration signal sequence, the overall state score of the fixture at the current sampling time is obtained. Based on the overall state score of the fixture at the current sampling time, the operating state of the fixture at the current sampling time is judged.

[0007] The beneficial effects of the embodiments of the present invention compared with the prior art are as follows: This invention, during the operation of the fixture, collects at least two vibration signal sequences from each part to be tested at the current sampling time, obtaining all vibration signal sequences for a preset number of parts to be tested. For any set of vibration signal sequences, the vibration signal at the current sampling time is obtained from the set of vibration signal sequences and recorded as the target signal. Based on the fluctuation characteristics of the set of vibration signal sequences, the outlier of the target signal is obtained. Based on the vibration signal type of the set of vibration signal sequences and the difference in vibration signals between each part to be tested at the current sampling time and vibration signal sequences of the same type as the set of vibration signal sequences, the state consistency index of the target signal is obtained. Based on the outlier and state consistency index of the target signal, the state score of the target signal is obtained. Based on the fluctuation characteristics of the set of vibration signal sequences, the fusion weight of the target signal is obtained. The state score and fusion weight of the target signal in each set of vibration signal sequences are obtained. Based on the state score and fusion weight of the target signal in each set of vibration signal sequences, the overall state score of the fixture at the current sampling time is obtained. Based on the overall state score of the fixture at the current sampling time, the operating state of the fixture at the current sampling time is judged. This invention collects various vibration signals from different parts of the fixture, and obtains a state score for each vibration signal based on the fluctuation characteristics of each vibration signal sequence and the differences between vibration signals between the sequences. The state scores of various vibration signals at the current sampling time are weighted and fused to obtain the overall state score of the fixture at the current sampling time. This not only achieves comprehensive monitoring of the fixture, but also makes the judgment of the fixture's operating status at the current sampling time more accurate, thus achieving more comprehensive, intuitive and accurate monitoring of the fixture. Attached Figure Description

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 these drawings without paying any creative work.

[0009] Figure 1 This is a flowchart of a method for real-time monitoring of the operating status of a fixture based on the Internet of Things, provided in Embodiment 1 of the present invention. Figure 2 This is an example diagram of a fixture provided in Embodiment 1 of the present invention. Detailed Implementation

[0010] Embodiments of this disclosure are described in detail below, with examples of these embodiments illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting it.

[0011] It should be noted that the terms "first," "second," etc., used in this disclosure and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure.

[0012] To illustrate the technical solution of the present invention, specific embodiments are described below.

[0013] This invention provides an IoT-based real-time monitoring system for the operating status of fixtures and tooling, including a processor and a memory. The processor executes a computer program in the memory to implement an IoT-based method for real-time monitoring of the operating status of fixtures and tooling. Figure 1 As shown, the method includes the following steps: Step S101: During the operation of the fixture, at least two vibration signal sequences of each part to be tested are collected at the current sampling time to obtain all vibration signal sequences of a preset number of parts to be tested.

[0014] To comprehensively monitor the fixture, this embodiment sets up different types of sensors at each inspected part of the fixture to collect various vibration signals from each inspected part during operation. The inspected parts in this embodiment are as follows: Figure 2 As shown, including but not limited to Figure 2 The system consists of four locations: location 1 is the connection between the fixture and the workpiece; location 2 is the connection between the fixture and the robotic arm; location 3 is the lever of the robotic arm; and location 4 is the connection between the lever and the robotic arm. Displacement sensors, velocity sensors, and acceleration sensors are installed at each location to be detected. The specific settings are not limited and can be adjusted according to the specific implementation scenario. This embodiment collects three vibration signals from each location to be detected over a 24-hour period, including the current sampling time, at a sampling frequency of once per second. Each vibration signal from a location to be detected forms a vibration signal sequence, resulting in 12 sets of vibration signal sequences from the four locations to be detected. The specific settings are not limited and can be adjusted according to the specific implementation scenario.

[0015] Step S102: For any set of vibration signal sequences, obtain the vibration signal at the current sampling time in the set of vibration signal sequences and record it as the target signal. According to the fluctuation characteristics of the set of vibration signal sequences, obtain the abnormal value of the target signal. According to the vibration signal type of the set of vibration signal sequences and the difference in vibration signals between each part to be detected at the current sampling time and the vibration signal type of the set of vibration signal sequences, obtain the state consistency index of the target signal.

[0016] Since the motion trajectories of each part to be tested in the fixture are the same under the same operating state, and most of them are repetitive operations, the obtained vibration signals are periodic. Moreover, the workpieces used are of the same specification, so the obtained vibration signals should fluctuate within a fixed range. If the vibration signal at the current sampling time does not meet the periodicity of the vibration signal or the amplitude of the vibration signal is not within a fixed range, then the vibration signal at the current sampling time may be abnormal, and the part to be tested where the vibration signal is located may have a problem. Therefore, for any set of vibration signal sequences, the vibration signal at the current sampling time in any set of vibration signal sequences is recorded as the target signal. Based on the fluctuation characteristics of any set of vibration signal sequences, the abnormal value of the target signal can be obtained. The state of the part to be tested where the target signal is located can be judged by the abnormal value of the target signal, and then the operating state of the fixture can be judged.

[0017] The method for obtaining outliers of the target signal based on the wave characteristics of any set of vibration signal sequences is as follows: Obtain the vibration period of any set of vibration signal sequences, and divide the any set of vibration signal sequences into at least two sub-sequences based on the vibration period; Obtain the number of extreme points in each subsequence of any set of vibration signal sequences, and obtain the absolute value of the first difference between the number of extreme points in the subsequence where the target signal is located and the number of extreme points in the first subsequence. Obtain the position number of the target signal in the subsequence where the target signal is located, and form a first target sequence by combining the amplitudes of vibration signals with the same position number as the target signal in each subsequence; Obtain the first quartile and the third quartile in the first target sequence, calculate the first mean of the first quartile and the third quartile, obtain the first difference between the amplitude of the target signal and the first mean, and obtain the maximum value between the first difference and the constant 0. The sum of the absolute value of the first difference and the maximum value is obtained as the outlier of the target signal.

[0018] In one embodiment, firstly, a Fourier transform is performed on any set of vibration signal sequences to obtain the spectrum of the sequence. The Fourier transform is prior art and will not be elaborated here. The vibration period of the vibration signal is obtained from the spectrum. Based on the vibration period, and according to the method of dividing the vibration signals in each vibration period into a subsequence, the set of vibration signal sequences is divided into at least two subsequences. The extreme points of each subsequence are obtained using the derivative method, and the number of extreme points in each subsequence is determined. The derivative method is prior art and will not be elaborated here. Then, the position number of the target signal is obtained in the subsequence containing the target signal. In each subsequence, the amplitude of the vibration signal with the same position number as the target signal is obtained, forming a first target sequence. The first quartile and third quartile of the first target sequence are obtained. The quartile method is prior art and will not be elaborated here. Finally, based on the number of extreme points in each subsequence, the first quartile and third quartile of the first target sequence, and the amplitude of the target signal, the outlier of the target signal is calculated. in, A1 represents the outlier of the target signal; Ai represents the number of extreme points in the first subsequence; i represents the number of extreme points in the subsequence containing the target signal; i represents the sequence number of any subsequence divided by a set of vibration signal sequences; Q1 represents the first quartile in the first target sequence; Q3 represents the third quartile in the first target sequence; x represents the amplitude of the target signal; | represents the absolute value sign; max() is the maximum value function.

[0019] It should be noted that the greater the difference between the number of extreme points in the first subsequence and the number of extreme points in the subsequence containing the target signal, the greater the possibility that the period of the vibration signal in the subsequence containing the target signal is abnormal, the larger the abnormal value of the target signal, and the more likely the fixture will malfunction. The greater the difference between the amplitude of the target signal and the mean of the first quartile and the third quartile in the first target sequence, the greater the possibility that the amplitude of the target signal exceeds the fixed range of the vibration signal amplitude, the larger the abnormal value of the target signal, and the more likely the fixture will malfunction.

[0020] During the operation of the fixture, although the motion trajectories of different parts to be inspected differ, each part has its own fixed motion trajectory under the same motion state. Therefore, each part will have its own characteristics. For example, when the fixture is in the workpiece transport state, the robotic arm moves horizontally with no significant change in the vertical direction. At this time, the lever of the robotic arm will have a horizontal displacement change, and vibration displacement signals can be monitored. Moreover, the movement of the robotic arm is generally uniform, so vibration velocity signals can be monitored, but vibration acceleration signals may not be monitored. At the same time, the vibration displacement at the front end of the lever near the connection between the fixture and the workpiece is greater than the vibration displacement at the rear end of the lever away from the connection, but the vibration velocities of the two parts to be inspected may be consistent. In addition, for parts to be inspected that are fixed by connection, the main moving part and the connecting part are not the same part to be inspected. The speed of the non-main moving part may be slightly lower than that of the main moving part, and it may fluctuate slightly due to the influence of passive force.

[0021] Therefore, based on the vibration signal type of any set of vibration signal sequences and the difference in vibration signals between each part to be detected and any set of vibration signal sequences of the same vibration signal type at the current sampling time, the state consistency index of the target signal can be obtained. The state of the part to be detected where the target signal is located can be judged by the state consistency of the target signal, and then the operating state of the fixture can be judged.

[0022] The method for obtaining the state consistency index of the target signal based on the vibration signal type of any set of vibration signal sequences and the difference in vibration signals between each part to be detected and any set of vibration signal sequences of the same vibration signal type at the current sampling time is as follows: Since this embodiment sets a displacement sensor, a velocity sensor and an acceleration sensor at each part to be detected, the vibration signal types include: vibration displacement signal, vibration velocity signal and vibration acceleration signal.

[0023] (1) When the vibration signal type of any set of vibration signal sequences is a vibration displacement signal, the connection between the fixture and the workpiece is set as the reference position, and the distance between the position of each part to be detected and the reference position is obtained to form a distance sequence. In each set of vibration signal sequences with the same vibration signal type as any set of vibration signal sequences, the amplitude of the vibration signal at the current sampling time is obtained to form an amplitude sequence. The amplitude sequence and the distance sequence are inversely fitted to obtain the fitting inverse proportional function of amplitude and distance. Obtain the first distance between the location of the target signal and the reference location, obtain the fitting amplitude of the first distance in the fitting inverse proportional function, calculate the absolute value of the second difference between the amplitude of the target signal and the fitting amplitude, and obtain the reciprocal of the absolute value of the second difference as the state consistency index of the target signal.

[0024] In one embodiment, when the vibration signal type of any set of vibration signal sequences is a vibration displacement signal, the amplitude of the vibration signal in any set of vibration signal sequences is the displacement. First, the connection point between the fixture and the workpiece is set as the reference position. The amplitudes of the vibration signals at the current sampling time in each set of vibration signal sequences of vibration displacement signal type are combined into an amplitude sequence. The distance between the position of the part to be detected and the reference position corresponding to each set of vibration signal sequences of vibration displacement signal type is combined into a distance sequence. The amplitude sequence and the distance sequence are inversely fitted to obtain the fitting inverse proportional function of the displacement of the part to be detected and its distance from the reference position at the current sampling time. The inverse fitting is a prior art and will not be described in detail here. Then, the distance between the position of the part to be detected where the target signal is located and the reference position is obtained, which is recorded as the first distance. The fitting amplitude of the first distance is obtained using the fitting inverse proportional function. Based on the fitting amplitude of the first distance and the actual amplitude of the target signal, the state consistency index of the target signal is calculated. in, For any set of vibration signal sequences, the vibration signal type is the vibration displacement signal, which is the state consistency index of the target signal; C is the first distance; The amplitude of the target signal is denoted by t; t is the current sampling time. represents the constant term in the inverse proportional function; | represents the absolute value symbol.

[0025] It should be noted that in a vibration signal sequence of the vibration displacement signal type, the amplitude of the vibration signal represents the displacement of the detected part. This represents the amplitude (i.e., the fitted displacement) of the distance between the target signal location and the reference location in the fitted inverse proportional function. This represents the difference between the actual displacement and the fitted displacement of the target signal. The smaller the value, the closer the actual displacement of the target signal matches the expected displacement of the part to be detected, the higher the consistency index of the target signal, and the more normal the operating state of the fixture. The larger the value, the less the actual displacement of the target signal matches the expected displacement of the part to be detected, the smaller the state consistency index of the target signal, and the more likely the fixture is to experience abnormal conditions.

[0026] (2) When the vibration signal type of any set of vibration signal sequences is a vibration velocity signal, the subsequence where the target signal is located is recorded as the first target subsequence, the first target subsequence is divided into at least one sequence segment according to a preset length, the curvature of each sequence segment is calculated respectively, and the first curvature mean value is obtained accordingly. The detection method detects whether the detection part of any set of vibration signal sequences has a displacement change relative to the fixture. If the detection part of any set of vibration signal sequences has no displacement change relative to the fixture, the reciprocal of the first curvature mean is obtained as the state consistency index of the target signal. If the detection part of any set of vibration signal sequences undergoes displacement relative to the fixture, the first phase of the target signal is obtained. In each set of vibration signal sequences with the same vibration signal type as the set of vibration signal sequences, the phase of the vibration signal at the current sampling time is obtained to form a second target sequence. The phase with the highest frequency in the second target sequence is obtained. The absolute value of the third difference between the first phase of the target signal and the phase with the highest frequency in the second target sequence is calculated. The third summation result of the absolute value of the third difference and the constant 1 is calculated. The average of the reciprocal of the third summation result and the reciprocal of the first curvature mean is obtained as the state consistency index of the target signal.

[0027] In one embodiment, when the vibration signal type of any set of vibration signal sequences is a vibration velocity signal, the subsequence containing the target signal is first designated as the first target subsequence. Following the method of dividing a sequence into segments of three vibration signals, the first target subsequence is divided into at least one segment (if there are fewer than three vibration signals in the first target subsequence, the vibration signals preceding the first target subsequence are used to supplement them). This is not limited here and can be set according to the specific implementation scenario. The curvature of each segment is calculated separately, and the average curvature of all segments is obtained and designated as the first average curvature. Curvature is existing technology and will not be elaborated here. Then, it is detected whether the part to be detected in any set of vibration signal sequences undergoes displacement relative to the fixture. If the part to be detected in any set of vibration signal sequences does not undergo displacement relative to the fixture, then the part to be detected in any set of vibration signal sequences is confirmed as a non-primary moving part. The movement of the non-primary moving part is then... The motion value is set to 0, which is not restricted here and can be set according to the specific implementation scenario. The state consistency index of the target signal is calculated based on the curvature of each sequence segment in the first target subsequence. If the detection part of any set of vibration signal sequences undergoes displacement relative to the fixture, then the detection part of any set of vibration signal sequences is identified as the main moving part, and the motion value of the main moving part is set to 1. This is not restricted here and can be set according to the specific implementation scenario. The phase of the target signal is obtained and recorded as the first phase. In each set of vibration signal sequences of vibration velocity signal type, the phase of the vibration signal at the current sampling time is obtained to form the second target sequence. The phase with the highest frequency in the second target sequence is obtained. The state consistency index of the target signal is calculated based on the difference between the first phase and the highest frequency phase in the second target sequence, as well as the curvature of each sequence segment in the first target subsequence. The calculation formula for the state consistency index of the target signal is as follows: in, For any set of vibration signal sequences, the vibration signal type is the vibration velocity signal, which is the state consistency index of the target signal. The mean of the first curvature; The first phase is represented by t, which is the current sampling time. The phase with the highest frequency in the second target sequence; P is the motion value; || is the absolute value symbol.

[0028] It should be noted that the smaller the mean value of the first curvature, the smaller the fluctuation of the first target subsequence, the more stable the vibration signal, and the greater the state consistency index of the target signal. Since the speed of the fixture is consistent under normal circumstances, the entire fixture operates at this speed, so there will be no difference in the phase of the vibration signal. The smaller the difference between the first phase and the highest frequency phase in the second target sequence, the more consistent the operating speed of the part to be detected where the target signal is located is with the normal speed, and the greater the state consistency index of the target signal. The greater the state consistency index of the target signal, the more normal the operating state of the fixture.

[0029] (3) When the vibration signal type of any set of vibration signal sequences is a vibration acceleration signal, the subsequence where the target signal is located is recorded as the second target subsequence, the second target subsequence is divided into at least one sequence segment according to a preset length, the curvature of each sequence segment is calculated respectively, and the second curvature mean value is obtained accordingly. The detection unit determines whether the part to be detected, in any one set of vibration signal sequences, has undergone displacement change relative to the fixture. If the part to be detected, in any one set of vibration signal sequences, has not undergone displacement change relative to the fixture, the reciprocal of the second mean curvature value is obtained as the state consistency index of the target signal. If the detection part of any set of vibration signal sequences undergoes displacement relative to the fixture, then the second phase of the target signal is obtained. In each set of vibration signal sequences with the same vibration signal type as the set of vibration signal sequences, the phase of the vibration signal at the current sampling time is obtained to form a third target sequence. The phase with the highest frequency in the third target sequence is obtained. The absolute value of the fourth difference between the second phase of the target signal and the phase with the highest frequency in the third target sequence is calculated. The fourth sum of the absolute value of the fourth difference and the constant 1 is calculated. The average of the reciprocal of the fourth sum and the reciprocal of the second curvature mean is obtained as the state consistency index of the target signal.

[0030] In one embodiment, when the vibration signal type of any set of vibration signal sequences is a vibration acceleration signal, the state consistency index of the target signal when the vibration signal type of any set of vibration signal sequences is a vibration velocity signal is obtained according to the above-mentioned method for obtaining the state consistency index of the target signal when the vibration signal type of any set of vibration signal sequences is a vibration acceleration signal.

[0031] Thus, the outliers and state consistency indices of the target signal are obtained.

[0032] Step S103: Based on the outlier value and state consistency index of the target signal, obtain the state score of the target signal; based on the fluctuation characteristics of any set of vibration signal sequences, obtain the fusion weight of the target signal.

[0033] After obtaining the outliers and state consistency index of the target signal, the state score of the target signal can be obtained based on the outliers and state consistency index. Then, based on the fluctuation characteristics of any set of vibration signal sequences, the fusion weight of the target signal can be obtained. By using the fusion weight and state score of the target signal, the state of the part to be detected where the target signal is located can be judged. Then, by fusing the state scores of various vibration signals of all parts to be detected at the current sampling time, the operating state of the fixture at the current sampling time can be judged.

[0034] The method for obtaining the state score of the target signal based on outliers and state consistency indicators is as follows: The outliers of the target signal are normalized to obtain normalized outliers. The difference between the constant 1 and the normalized outliers is calculated. The second mean of the state consistency index of the target signal and the subtraction result is calculated. The second mean of the preset multiple is used as the state score of the target signal.

[0035] In one embodiment, the formula for calculating the state score of the target signal based on the outlier values ​​and state consistency index of the target signal is as follows: in, Score the state of the target signal; These are outliers in the target signal; is the state consistency index of the target signal; v is the index of the vibration signal type; norm() is the normalization function; 10 is the preset multiple.

[0036] It should be noted that the smaller the outlier of the target signal, the more the target signal satisfies the periodicity of the vibration signal it is in or the amplitude of the target signal is within the normal range, and the higher the state score of the target signal. The higher the state consistency index of the target signal, the more the detected part of the target signal conforms to the expected motion state, and the higher the state score of the target signal. The higher the state score of the target signal, the more normal the operating state of the fixture.

[0037] The method for obtaining the fusion weight of the target signal based on the wave characteristics of any set of vibration signal sequences is as follows: The maximum amplitude value in the subsequence containing the target signal is obtained. The maximum amplitude value in each subsequence at the current sampling time in each vibration signal sequence is obtained and accumulated to obtain the corresponding accumulated value. The ratio of the maximum amplitude value in the subsequence containing the target signal to the accumulated value is calculated and used as the fusion weight of the target signal.

[0038] In one implementation, the maximum amplitude value in the subsequence of each vibration signal at the current sampling time is obtained, and the fusion weight of the target signal is calculated: Where Y is the fusion weight of the target signal; The maximum amplitude value in the subsequence containing the target signal; E represents the maximum amplitude value in the subsequence containing the e-th vibration signal at the current sampling time; e is the sequence number of the vibration signal sequence; and E is the number of vibration signal sequences.

[0039] It should be noted that the larger the maximum amplitude value in the subsequence containing the target signal, the greater the influence on the target signal under the current operating state, and the greater the fusion weight of the target signal.

[0040] Thus, the state score and fusion weight of the target signal are obtained.

[0041] Step S104: Obtain the state score and fusion weight of the target signal in each vibration signal sequence; obtain the overall state score of the fixture at the current sampling time based on the state score and fusion weight of the target signal in each vibration signal sequence; and determine the operating state of the fixture at the current sampling time based on the overall state score of the fixture at the current sampling time.

[0042] After obtaining the state score and fusion weight of the target signal, the state score and fusion weight of the target signal (that is, each vibration signal of each part to be detected at the current sampling time) in each set of vibration signal sequences can be obtained according to the method of obtaining the state score and fusion weight of the target signal. Then, based on the state score and fusion weight of the target signal in each set of vibration signal sequences, the overall state score of the fixture at the current sampling time can be obtained, and the operating state of the fixture at the current sampling time can be judged.

[0043] The method for obtaining the overall state score of the fixture at the current sampling moment based on the state score and fusion weight of the target signal in each vibration signal sequence is as follows: Based on the fusion weight of the target signal in each vibration signal sequence, the state scores of the target signals in all vibration signal sequences are weighted and summed to obtain the overall state score of the fixture at the current sampling time.

[0044] In one embodiment, the formula for calculating the overall state score of the fixture at the current sampling time is: in, The overall state score of the fixture at the current sampling moment; The fusion weights are the values ​​for the e-th target signal at the current sampling time. The state score of the e-th target signal at the current sampling time is given; e is the sequence number of the vibration signal sequence; E is the number of vibration signal sequences; and t is the current sampling time.

[0045] It should be noted that the higher the status score of each target signal at the current sampling time, the more normal each target signal is at the current sampling time, the higher the overall status score of the fixture at the current sampling time, and the more normal the operating status of the fixture.

[0046] After obtaining the overall status score of the fixture at the current sampling time, the overall status score of the fixture integrates the vibration signals of all vibration types of all parts to be tested in the fixture, which can monitor the operating status of the fixture more comprehensively, intuitively and accurately. Therefore, the operating status of the fixture at the current sampling time can be judged by the overall status score of the fixture at the current sampling time.

[0047] Specifically, an overall status score threshold range is set, which includes a first abnormal range, a second abnormal range, a third abnormal range, and a normal range. The overall status score of the first abnormal range is less than the overall status score of the second abnormal range, the overall status score of the second abnormal range is less than the overall status score of the third abnormal range, and the overall status score of the third abnormal range is less than the overall status score of the normal range. When the overall status score of the fixture at the current sampling time is in the first abnormal range, it is confirmed that the fixture is in a severely abnormal operating state. When the overall status score of the fixture at the current sampling time is in the second abnormal range, it is confirmed that the fixture is in a moderately abnormal operating state. When the overall status score of the fixture at the current sampling time is in the third abnormal interval, it is confirmed that the fixture is in a slightly abnormal operating state. When the overall status score of the fixture at the current sampling time is within the normal range, the fixture is confirmed to be in normal operating condition.

[0048] In one embodiment, the overall status score threshold range is set to [0, 10], the first abnormal range is set to [0, 6), the second abnormal range is set to [6, 8), the third abnormal range is set to [8, 9), and the normal range is set to [9, 10]. There are no restrictions here, and the range can be set according to the specific implementation scenario. When the overall status score of the fixture at the current sampling time is in the range [0, 6), it is confirmed that the fixture is in a severely abnormal operating state and maintenance measures are required. When the overall status score of the fixture at the current sampling time is in the range [6, 8), it is confirmed that the fixture is in a moderately abnormal operating state and manual observation is required to determine whether the fixture has malfunctioned. When the overall status score of the fixture at the current sampling time is in the range [8, 9), it is confirmed that the fixture is in a slightly abnormal operating state and monitoring needs to continue. If the overall status score of the fixture is in the range [9, 10] after 3-5 sampling times, it is confirmed that the fixture is in a normal operating state. If the overall status score of the fixture is not in the range [9, 10] after 3-5 sampling times, manual observation is required. There is no restriction here, and it can be set according to the specific implementation scenario. When the overall status score of the fixture at the current sampling time is in the range [9, 10], it is confirmed that the fixture is in a normal operating state.

[0049] In summary, during the operation of the fixture, this embodiment of the invention collects at least two vibration signal sequences for each part to be tested at the current sampling time, obtaining all vibration signal sequences for a preset number of parts to be tested. For any set of vibration signal sequences, the vibration signal at the current sampling time is obtained from the set of vibration signal sequences and recorded as the target signal. Based on the fluctuation characteristics of the set of vibration signal sequences, the outlier of the target signal is obtained. Based on the vibration signal type of the set of vibration signal sequences and the difference in vibration signals between each part to be tested at the current sampling time and vibration signal sequences of the same vibration signal type as the set of vibration signal sequences, the state consistency index of the target signal is obtained. Based on the outlier and state consistency index of the target signal, the state score of the target signal is obtained. Based on the fluctuation characteristics of the set of vibration signal sequences, the fusion weight of the target signal is obtained. The state score and fusion weight of the target signal in each set of vibration signal sequences are obtained. Based on the state score and fusion weight of the target signal in each set of vibration signal sequences, the overall state score of the fixture at the current sampling time is obtained. Based on the overall state score of the fixture at the current sampling time, the operating state of the fixture at the current sampling time is judged. This invention collects various vibration signals from different parts of the fixture, and obtains a status score for each vibration signal based on the fluctuation characteristics of each vibration signal sequence and the differences between vibration signals in the sequences. The status scores of various vibration signals at the current sampling time are weighted and fused to obtain the overall status score of the fixture at the current sampling time. This not only achieves comprehensive monitoring of the fixture, but also makes the judgment of the fixture's operating status at the current sampling time more accurate, thus achieving more comprehensive, intuitive and accurate monitoring of the fixture.

[0050] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention 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 make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A real-time monitoring system for the operation status of a fixture based on the Internet of Things, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the following method is implemented: During the operation of the fixture, at least two vibration signal sequences of each part to be detected at the current sampling time are collected to obtain all vibration signal sequences of a preset number of parts to be detected; For any group of vibration signal sequences, a vibration signal at a current sampling moment is obtained from the any group of vibration signal sequences and recorded as a target signal; an abnormal value of the target signal is obtained according to a fluctuation characteristic of the any group of vibration signal sequences; and a state consistency index of the target signal is obtained according to a vibration signal type of the any group of vibration signal sequences and a difference in vibration signals between vibration signal sequences of the same vibration signal type as that of the any group of vibration signal sequences at each part to be detected at the current sampling moment; According to the abnormal value and state consistency index of the target signal, the state score of the target signal is obtained, and according to the fluctuation characteristics of the arbitrary group of vibration signal sequences, the fusion weight of the target signal is obtained; The state score and fusion weight of the target signal in each group of vibration signal sequences are obtained, and the overall state score of the fixture at the current sampling moment is obtained based on the state score and fusion weight of the target signal in each group of vibration signal sequences. The operating state of the fixture at the current sampling moment is judged based on the overall state score of the fixture at the current sampling moment.

2. The real-time monitoring system for fixture operation status based on the Internet of Things according to claim 1 is characterized in that: The obtaining, according to the fluctuation characteristics of the arbitrary group of vibration signal sequences, the abnormal value of the target signal comprises: Obtaining a vibration period of the arbitrary group of vibration signal sequences, and dividing the arbitrary group of vibration signal sequences into at least two subsequences according to the vibration period; Obtain the number of extreme value points of each subsequence in the arbitrary group of vibration signal sequences, and obtain the first absolute value of the difference between the number of extreme value points of the subsequence where the target signal is located and the number of extreme value points of the first subsequence; Obtaining the position number of the target signal in the subsequence where the target signal is located, and combining the amplitudes of the vibration signals having the same position number as the target signal in each subsequence into a first target sequence; Obtaining a first quartile and a third quartile in the first target sequence, calculating a first mean of the first quartile and the third quartile, obtaining a first difference between the amplitude of the target signal and the first mean, and obtaining a maximum value between the first difference and a constant 0; A sum of the first difference absolute value and the maximum value is obtained as an abnormal value of the target signal.

3. The real-time monitoring system for fixture operation status based on the Internet of Things according to claim 2 is characterized in that: The obtaining of the state consistency index of the target signal according to the vibration signal type of the arbitrary group of vibration signal sequences and the difference in vibration signals between each to-be-detected part and the vibration signal sequence of the same vibration signal type as the arbitrary group of vibration signal sequences at the current sampling moment comprises: The vibration signal types include: vibration displacement signal, vibration velocity signal and vibration acceleration signal; When the vibration signal type of any one group of vibration signal sequences is a vibration displacement signal, the connection point between the fixture and the workpiece is set as a reference position, the distance between the position of each part to be detected and the reference position is obtained to form a distance sequence, and in each group of vibration signal sequences with the same vibration signal type as the any one group of vibration signal sequences, the amplitude of the vibration signal at the current sampling moment is obtained to form an amplitude sequence, and the amplitude sequence and the distance sequence are inversely fitted to obtain a fitted inverse proportional function of amplitude and distance; Obtain a first distance between the position of the to-be-detected part where the target signal is located and the reference position, obtain a fitting amplitude of the first distance in the fitted inverse proportional function, calculate a second absolute value of a difference between the amplitude of the target signal and the fitting amplitude, and obtain the inverse of the absolute value of the second difference as a state consistency indicator of the target signal.

4. The real-time monitoring system for fixture operation status based on the Internet of Things according to claim 3 is characterized in that: The step of obtaining the state consistency index of the target signal according to the vibration signal type of the arbitrary group of vibration signal sequences and the difference in vibration signals between each vibration signal sequence of the to-be-detected part having the same vibration signal type as the arbitrary group of vibration signal sequences at the current sampling moment, further includes: When the vibration signal type of any one of the group of vibration signal sequences is a vibration velocity signal, the subsequence in which the target signal is located is recorded as a first target subsequence, the first target subsequence is divided into at least one sequence segment according to a preset length, the curvature of each sequence segment is calculated respectively, and a first curvature mean is obtained accordingly; Detecting whether the to-be-detected part where any one group of vibration signal sequences is located has a displacement change relative to the fixture; if the to-be-detected part where any one group of vibration signal sequences is located has not a displacement change relative to the fixture, obtaining the inverse of the first curvature mean as a state consistency indicator of the target signal; If the part to be detected where any one of the groups of vibration signal sequences is located produces a displacement change relative to the fixture, the first phase of the target signal is obtained, and in each group of vibration signal sequences with the same vibration signal type as the any one of the groups of vibration signal sequences, the phase of the vibration signal at the current sampling moment is obtained to form a second target sequence, and the phase with the highest frequency in the second target sequence is obtained. The absolute value of the third difference between the first phase of the target signal and the phase with the highest frequency in the second target sequence is calculated, and the third addition result of the third absolute value of the difference and the constant 1 is calculated. The average of the inverse of the third addition result and the inverse of the first curvature mean is obtained as the state consistency indicator of the target signal.

5. The real-time monitoring system for fixture operation status based on the Internet of Things according to claim 3 is characterized in that: The step of obtaining the state consistency index of the target signal according to the vibration signal type of the arbitrary group of vibration signal sequences and the difference in vibration signals between each vibration signal sequence of the to-be-detected part having the same vibration signal type as the arbitrary group of vibration signal sequences at the current sampling moment, further includes: When the vibration signal type of any one of the group of vibration signal sequences is a vibration acceleration signal, the subsequence where the target signal is located is recorded as a second target subsequence, the second target subsequence is divided into at least one sequence segment according to a preset length, and the curvature of each sequence segment is calculated respectively, so as to obtain a corresponding second curvature mean; Detecting whether the to-be-detected part where any one group of vibration signal sequences is located has a displacement change relative to the fixture; if the to-be-detected part where any one group of vibration signal sequences is located has not a displacement change relative to the fixture, obtaining the inverse of the second curvature mean as a state consistency indicator of the target signal; If the part to be detected where any one of the groups of vibration signal sequences is located produces a displacement change relative to the fixture, the second phase of the target signal is obtained, and in each group of vibration signal sequences with the same vibration signal type as the any one of the groups of vibration signal sequences, the phase composition of the vibration signal at the current sampling moment is obtained to form a third target sequence, and the phase with the highest frequency in the third target sequence is obtained. The fourth absolute value of the difference between the second phase of the target signal and the phase with the highest frequency in the third target sequence is calculated, and the fourth addition result of the fourth absolute value of the difference and the constant 1 is calculated. The average of the inverse of the fourth addition result and the inverse of the second curvature mean is obtained as the state consistency indicator of the target signal.

6. The real-time monitoring system for fixture operation status based on the Internet of Things according to claim 1 is characterized in that: The step of obtaining a state score of the target signal according to the abnormal value and the state consistency index of the target signal includes: Normalize the outlier value of the target signal to obtain a normalized outlier value, calculate the subtraction result of a constant 1 and the normalized outlier value, calculate the second mean of the subtraction result and the state consistency index of the target signal, and obtain the second mean of a preset multiple as the state score of the target signal.

7. The real-time monitoring system for fixture operation status based on the Internet of Things according to claim 2 is characterized in that: The obtaining the fusion weight of the target signal according to the fluctuation characteristics of the arbitrary group of vibration signal sequences includes: The maximum amplitude in the subsequence where the target signal is located is obtained, and the maximum amplitude in each subsequence at the current sampling moment in each group of vibration signal sequences is obtained and accumulated to obtain the corresponding accumulated value, and the ratio of the maximum amplitude in the subsequence where the target signal is located to the accumulated value is calculated as the fusion weight of the target signal.

8. The real-time monitoring system for fixture operation status based on the Internet of Things according to claim 1 is characterized in that: The step of obtaining the overall state score of the fixture at the current sampling moment according to the state score and fusion weight of the target signal in each group of vibration signal sequences includes: According to the fusion weight of the target signal in each group of vibration signal sequences, the state scores of the target signals in all vibration signal sequences are weighted and summed to obtain the overall state score of the fixture at the current sampling moment.

9. The real-time monitoring system for fixture operation status based on the Internet of Things according to claim 8 is characterized in that: The step of judging the operating state of the fixture at the current sampling moment according to the overall state score of the fixture at the current sampling moment includes: Setting an overall status score threshold interval, wherein the overall status score threshold interval includes a first abnormal interval, a second abnormal interval, a third abnormal interval and a normal interval, the overall status score of the first abnormal interval is less than the overall status score of the second abnormal interval, the overall status score of the second abnormal interval is less than the overall status score of the third abnormal interval, and the overall status score of the third abnormal interval is less than the overall status score of the normal interval; When the overall state score of the fixture at the current sampling moment is in the first abnormal interval, it is confirmed that the fixture is in a severely abnormal operating state; When the overall state score of the fixture at the current sampling moment is in the second abnormal interval, it is confirmed that the fixture is in a moderately abnormal operating state; When the overall state score of the clamp at the current sampling moment is in the third abnormal interval, it is confirmed that the clamp is in a slightly abnormal operation state; When the overall status score of the clamp at the current sampling moment is within the normal range, it is confirmed that the clamp is in a normal operating state.

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