A control system for a self-feeding horizontal band saw

Abstract

The present invention relates to the field of band saw control, and more specifically to a self-feeding horizontal band saw control system. The system first collects vibration signals and torque signals from the band saw within a preset time period before the current moment, decomposes the portion of the vibration signal within a preset time domain at a target moment, and obtains an interference index at the target moment based on the frequency bandwidth and overall intensity of each IMF signal at the target moment, the time-series distribution of the center frequency of the IMF signal within the preset time domain at the target moment, and the difference in decomposition residuals between the target moment and each moment in the preset time domain. Based on the distribution and variation of the interference index at each moment in the preset time period, and the time-series correlation between the interference index and the torque signal within the preset time period, a sawing speed adjustment weight at the current moment is obtained. Based on the sawing speed adjustment weight, the sawing speed of the band saw is adjusted in real time. The present invention can improve the control effect of a horizontal band saw.

Description

Technical Field

[0001] The invention relates to the field of band saw machine control, and in particular to a self-feeding horizontal band saw machine control system. Background Art

[0002] Horizontal band saws are capable of high-precision cutting of various metal profiles. They can accurately complete cutting tasks according to the set dimensions, so that the cut materials can meet the requirements of subsequent processing procedures. Some band saws can complete automatic feeding, which reduces the complexity of manual operation compared to manual feeding. At the same time, one person can operate multiple devices, greatly improving processing efficiency, and the cutting accuracy can reach the millimeter level.

[0003] In the related art, instructions are usually used to complete the setting of various parameters such as sawing paths and speeds, and during the sawing process, these parameters are usually kept unchanged, thereby completing the sawing task of the sawing material. However, due to the presence of hard foreign matter inside the sawing material and the load changes of the horizontal band saw during operation, the sawing speed of the horizontal band saw needs to be adjusted to avoid affecting the sawing quality, which results in the inability of the existing method to adjust the sawing speed in a timely and effective manner, reducing the control effect of the horizontal band saw. Summary of the Invention

[0004] In order to solve the technical problem that the existing method cannot timely and effectively adjust the sawing speed and reduces the control effect of the horizontal band saw machine, the purpose of the present invention is to provide a self-feeding horizontal band saw machine control system, and the technical solution adopted is as follows:

[0005] The present invention also proposes a self-feeding horizontal band saw control system, the system comprising:

[0006] A data acquisition module is used to obtain a vibration signal and a torque signal of the self-feeding horizontal band saw within a preset time period before a current moment;

[0007] An anomaly analysis module is used to take any moment within a preset time period as a target moment, decompose the portion of the vibration signal within the preset time domain at the target moment, obtain the decomposition residual and multiple IMF signals at the target moment, and the center frequency, frequency bandwidth, and overall strength of each IMF signal; based on the center frequency, label all IMF signals at the target moment to obtain the sequence number value of each IMF signal at the target moment; obtain the sawing anomaly index of each IMF signal at the target moment based on the frequency bandwidth and overall strength of each IMF signal at the target moment, and the distribution of the center frequency of IMF signals with the same sequence number value at different moments in the preset time domain at the target moment;

[0008] An adjustment weight analysis module is configured to obtain an interference index at a target moment based on the distribution of the sawing anomaly index of the IMF signal with the same sequence number value at different moments in a preset time domain at the target moment, and the difference in the decomposition residuals between the target moment and each moment in the preset time domain; and obtain a sawing speed adjustment weight at the current moment based on the distribution and change of the interference index at each moment in a preset time period, and the temporal correlation between the interference index and the torque signal in the preset time period;

[0009] The sawing speed adjustment module is used to adjust the sawing speed of the band saw in real time based on the sawing speed adjustment weight.

[0010] Furthermore, obtaining the sawing anomaly index of each IMF signal at the target moment includes:

[0011] Taking any sequence number value as the target sequence number value, integrating the frequency bandwidth and the overall strength of the IMF signal of the target sequence number value at the target time and performing normalization processing to obtain a first anomaly coefficient of the IMF signal with respect to the target sequence number value at the target time;

[0012] Analyzing the degree of dispersion of the center frequency of the IMF signal of the target sequence value at all moments in the preset time domain at the target moment to obtain a second abnormal coefficient of the IMF signal of the target sequence value at the target moment;

[0013] The first abnormal coefficient and the second abnormal coefficient are combined to obtain a sawing abnormality index of the IMF signal with respect to the target sequence value at the target moment.

[0014] Furthermore, obtaining a second abnormal coefficient of the IMF signal with respect to the target sequence value at the target time includes:

[0015] Normalize the standard deviation of the center frequency of the IMF signal of the target sequence value at all moments in the preset time domain at the target moment to obtain a second abnormal coefficient of the IMF signal about the target sequence value at the target moment.

[0016] Furthermore, obtaining the interference index at the target time includes:

[0017] Obtaining a first interference coefficient at the target moment according to the distribution of the sawing abnormality indicator of the IMF signal with the same sequence number value at different moments in the preset time domain at the target moment;

[0018] The absolute value of the difference between the average value of the decomposition residuals at all moments in the preset time domain of the target moment and the decomposition residuals at the target moment is used as the numerator, the standard deviation of the decomposition residuals at all moments in the preset time domain of the target moment is used as the denominator, and the ratio is used as the second interference coefficient at the target moment;

[0019] The first interference coefficient and the second interference coefficient are combined to obtain an interference index at a target moment.

[0020] Furthermore, obtaining the first interference coefficient at the target time includes:

[0021] Performing linear fitting on the sawing anomaly indicator of the IMF signal with the same sequence number value at all moments in the preset time domain at the target moment, and taking the angle between the fitted straight line and the horizontal direction as the fluctuation degree of the IMF signal for each sequence number value at the target moment;

[0022] The average value of the fluctuation degree of the IMF signal of all sequence values ​​at the target moment is used as the first interference coefficient at the target moment.

[0023] Furthermore, obtaining the sawing speed adjustment weight at the current moment includes:

[0024] Taking the average value of the interference index at all times within the preset time period as the overall interference index of the preset time period;

[0025] The absolute value of the difference between the overall interference index and the interference index at the first moment in the preset time period is used as the interference index deviation value at the current moment;

[0026] Obtaining a degree of change in the interference index at a current moment according to a difference in the interference index between two adjacent moments within a preset time period;

[0027] Combining the interference indicator deviation value and the interference indicator change degree to obtain a first adjustment evaluation value at a current moment;

[0028] sorting the interference indicators at all moments in a preset time period and the torque data of the torque signal at all moments in time in chronological order to obtain an interference indicator sequence and a torque sequence, performing negative correlation mapping on the absolute values ​​of the Pearson correlation coefficients between the interference indicator sequence and the torque sequence to obtain a second adjustment evaluation value at the current moment;

[0029] The first adjustment evaluation value and the second adjustment evaluation value are integrated and normalized to obtain the sawing speed adjustment weight at the current moment.

[0030] Furthermore, obtaining the interference index change degree at the current moment includes:

[0031] Any two adjacent moments within a preset time period are regarded as an adjacent moment group, and the absolute value of the difference between the interference indicators of the two moments in each adjacent moment group is regarded as the interference indicator variation of each adjacent moment group;

[0032] The average value of the interference index change amounts of all adjacent time groups is used as the interference index change degree at the current moment.

[0033] Furthermore, the real-time adjustment of the sawing speed of the band saw includes:

[0034] The product of the sawing speed adjustment weight and the standard sawing speed at the current moment is used as the sawing speed adjustment amount at the current moment;

[0035] The difference between the standard sawing speed and the sawing speed adjustment amount at the current moment is used as the adjusted sawing speed at the current moment.

[0036] Furthermore, obtaining the sequence number value of each IMF signal at the target time includes:

[0037] Using non-zero natural numbers, all IMF signals at the target time are numbered according to the ascending order of the center frequency to obtain the sequence number value of each IMF signal at the target time.

[0038] Furthermore, obtaining the decomposition residual and multiple IMF signals at the target time and the center frequency, frequency bandwidth and overall strength of each IMF signal includes:

[0039] Using the variational mode decomposition algorithm, the vibration signal is decomposed in the preset time domain at the target time to obtain the decomposition residual and multiple IMF signals at the target time as well as the center frequency of each IMF signal;

[0040] Perform frequency domain conversion on each IMF signal at the target moment to obtain the spectrum of each IMF signal at the target moment, and combine the spectrum of each IMF signal at the target moment to obtain the frequency bandwidth and overall strength of each IMF signal at the target moment.

[0041] The present invention has the following beneficial effects:

[0042] The present invention takes into account that the existing methods cannot timely and effectively adjust the sawing speed, which reduces the effect of controlling the horizontal band saw machine. Therefore, the vibration signal and torque signal of the automatic horizontal band saw machine in the preset time period before the current moment are first obtained. Considering that the presence of hard foreign matter in the sawing process will cause abnormal vibration of the band saw machine, making the vibration signal have obvious bands of different frequencies, the part of the vibration signal in the preset time domain at the target moment is first decomposed, and all IMF signals at the target moment are numbered, so as to facilitate the subsequent comprehensive analysis of the characteristics of the IMF signals with the same serial number value at different moments. Considering that when the sawing occurs at the target moment, the vibration signal is decomposed into the part of the preset time domain at the target moment, and the IMF signals are numbered. When abnormal, the frequency bandwidth and overall strength of the IMF signal are large, and the consistency of the center frequency of the IMF signals with the same serial number value at different times in the preset time domain of the target moment is poor. Therefore, the sawing abnormality index can be used to reflect the sawing abnormality characteristics of the target moment exhibited by each IMF signal. Considering that the interference of foreign matter in the sawing process will introduce additional high-frequency signals, the decomposed low-frequency IMF signal will be affected. Therefore, the interference index is used to reflect the degree of interference in the sawing process at the target moment, and then the sawing speed of the band saw is adjusted in real time by the obtained sawing speed adjustment weight, thereby improving the speed control effect of the horizontal band saw. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. 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.

[0044] Figure 1 This is a block diagram of a control system for a self-feeding horizontal band saw provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0045] To further illustrate the technical means and effectiveness of the present invention in achieving its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, describes in detail the specific implementation, structure, features, and effectiveness of a self-feeding horizontal band saw control system according to the present invention. In the following description, different references to "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0046] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0047] The specific scheme of the control system of a self-feeding horizontal band saw provided by the present invention is described in detail below with reference to the accompanying drawings.

[0048] See also Figure 1 , which shows a block diagram of a control system of a self-feeding horizontal band saw provided by an embodiment of the present invention. The system includes a data acquisition module 101, an abnormality analysis module 102, an adjustment weight analysis module 103 and a sawing speed adjustment module 104.

[0049] The data acquisition module 101 is used to obtain the vibration signal and torque signal of the self-feeding horizontal band saw within a preset time period before the current moment.

[0050] Self-feeding horizontal band saws will vibrate during operation, especially when there are hard foreign objects in the sawing material. The saw blade will vibrate more severely when sawing the foreign objects. When the vibration phenomenon is more obvious, if the sawing speed remains unchanged, it will lead to abnormal conditions such as deviation of the sawing path. At the same time, the hardness of the foreign objects in the sawing material is much higher than the sawing material itself. If the previous sawing torque is still maintained at this time, the sawing process of the material will not be able to proceed smoothly, or the sawing position will be offset, thereby affecting the sawing quality.

[0051] Therefore, in an embodiment of the present invention, a vibration sensor is first installed near the saw blade, and the vibration signal of the self-feeding horizontal band saw machine within a preset time period before the current moment is collected through the vibration sensor. At the same time, a torque sensor is installed at the spindle position of the horizontal band saw machine, and the torque signal of the self-feeding horizontal band saw machine within a preset time period before the current moment is collected through the torque sensor. The preset time period is usually 3 to 5 seconds. In one embodiment of the present invention, the preset time period is set to 3 seconds. The specific value of the preset time period can also be set by the implementer according to the specific implementation scenario, and is not limited here.

[0052] The anomaly analysis module 102 is used to take any moment within a preset time period as the target moment, decompose the part of the vibration signal in the preset time domain at the target moment, and obtain the decomposition residual and multiple IMF signals at the target moment, as well as the center frequency, frequency bandwidth and overall strength of each IMF signal; based on the center frequency, label all IMF signals at the target moment to obtain the serial number value of each IMF signal at the target moment; and obtain the sawing anomaly index of each IMF signal at the target moment based on the frequency bandwidth and overall strength of each IMF signal at the target moment and the distribution of the center frequencies of IMF signals with the same serial number value at different moments in the preset time domain at the target moment.

[0053] During normal sawing, torque remains stable, or it may exhibit periodic, small fluctuations due to systematic vibrations generated by sawing. However, if hard foreign matter is present in the material being sawed, the hardness of the material varies significantly at different locations, causing the horizontal band saw to experience a sudden increase in resistance when cutting the hardest area, leading to a sharp increase in torque during the sawing process. This destabilizes torque. Furthermore, the presence of foreign matter can cause significant vibration anomalies during the sawing process, resulting in distinct frequency bands in the vibration signal. Therefore, an embodiment of the present invention first analyzes any moment within a preset time period, designating it as a target moment. The portion of the vibration signal within a preset time domain at the target moment is then decomposed to obtain the decomposition residual and multiple IMF signals at the target moment, as well as the center frequency, frequency bandwidth, and overall intensity of each IMF signal. In one embodiment of the present invention, the length of the preset time domain is set to 0.5 seconds, meaning that the preset time domain at the target moment encompasses the 0.5 seconds closest to the target moment.

[0054] Preferably, in one embodiment of the present invention, the method for obtaining the decomposition residual and multiple IMF signals at the target time and the center frequency, frequency bandwidth and overall strength of each IMF signal specifically includes:

[0055] First, a variational mode decomposition (VMD) algorithm is used to decompose the portion of the vibration signal within a preset time domain at the target moment to obtain the decomposition residual and multiple IMF signals at the target moment, as well as the center frequency of each IMF signal. In one embodiment of the present invention, the number of decomposed IMF signals at the target moment is set to 8. The number of decomposed IMF signals can also be set by the implementer according to the specific implementation scenario and is not limited here.

[0056] Among them, the variational mode decomposition algorithm is a technical means well known to those skilled in the art. At the same time, the variational mode decomposition algorithm can automatically calculate the decomposition residual of each decomposition and the center frequency of each decomposed IMF signal, which will not be described in detail here.

[0057] Then, each IMF signal at the target moment is converted into the frequency domain to obtain a spectrum diagram of each IMF signal at the target moment. Combined with the spectrum diagram of each IMF signal at the target moment, the frequency bandwidth and overall strength of each IMF signal at the target moment are obtained. The method of obtaining the frequency bandwidth and the overall strength by combining the spectrum diagram is a technical means well known to those skilled in the art and will not be elaborated here. For example, the frequency bandwidth of each IMF signal can be calculated using a 3dB bandwidth (half-power bandwidth) or a Null-to-Null bandwidth method, and the average value of the amplitude of the spectrum diagram of each IMF signal at all frequencies at the target moment can be used as the overall strength of each IMF signal.

[0058] Since the center frequencies of the IMF signals at the target moment are different, the embodiment of the present invention also needs to label all the IMF signals at the target moment based on the center frequency to obtain the serial number value of each IMF signal at the target moment, so as to facilitate the subsequent comprehensive analysis of the characteristics of the IMF signals with the same serial number value at different moments, thereby accurately analyzing the abnormal conditions caused by interference from foreign objects during the sawing process.

[0059] Preferably, in one embodiment of the present invention, the method for obtaining the sequence number value of each IMF signal at the target time specifically includes:

[0060] Using non-zero natural numbers, all IMF signals at the target time are sorted in ascending order of center frequency, and the sequence number value of each IMF signal at the target time is obtained. For example, in one embodiment of the present invention, 8 IMF signals are decomposed from the portion of the vibration signal in the preset time domain at the target time. The sequence number value of the IMF signal with the smallest center frequency is 1, and the sequence number value of the IMF signal with the smallest center frequency is 8. In other embodiments of the present invention, the sequence number can also be sorted in descending order of center frequency, which is not limited here.

[0061] The same method as above can be used to obtain the decomposition residual and multiple IMF signals at each moment in the preset time period, as well as the center frequency, frequency bandwidth and overall strength of each IMF signal, and at the same time, the multiple IMF signals corresponding to each moment can be numbered.

[0062] When there is interference from hard foreign matter during the sawing process, the cutting resistance will suddenly increase. This additional resistance will cause the saw blade to produce an impact load, resulting in intensified vibration and increased vibration frequency. Therefore, the decomposed IMF signal shows a high overall intensity, and the vibration frequency distribution of the IMF signal is more divergent, that is, the frequency bandwidth of the IMF signal is large. At the same time, the consistency of the center frequency of the IMF signal with the same serial number value at different times in the preset time domain of the target moment is poor. At this time, it indicates that the possibility and degree of abnormality in the sawing process expressed by the IMF signal are relatively high. Therefore, the frequency bandwidth, overall intensity of each IMF signal at the target moment, and the distribution of the center frequency of the IMF signal with the same serial number value at different times in the preset time domain of the target moment can be analyzed, and the sawing abnormality characteristics of the target moment expressed by each IMF signal can be reflected by the obtained sawing abnormality index.

[0063] Preferably, in one embodiment of the present invention, the method for obtaining the sawing abnormality index of each IMF signal at the target moment specifically includes:

[0064] First, any sequence number value is taken as the target sequence number value. The frequency bandwidth and overall strength of the IMF signal of the target sequence number value at the target moment are integrated and normalized, and the calculation result is limited to the range of [0,1] to obtain the first anomaly coefficient of the IMF signal of the target sequence number value at the target moment.

[0065] In an embodiment of the present invention, the combination of the two can be achieved by calculating the sum or product of the frequency bandwidth and the overall strength of the IMF signal of the target sequence value at the target moment. This is not limited here, and the subsequent steps of the comprehensive processing of two or more data can also be achieved using the same method.

[0066] In one embodiment of the present invention, the normalization processing can be specifically, for example, maximum and minimum value normalization processing, and the normalization in subsequent steps can all adopt maximum and minimum value normalization processing. In other embodiments of the present invention, other normalization methods can be selected according to the specific range of values, or activation functions and hyperbolic tangent functions can be used to implement normalization processing, which will not be repeated or limited.

[0067] Then, the greater the degree of discreteness of the center frequency of the IMF signal of the target sequence number value at all moments in the preset time domain of the target moment, the worse the consistency of the center frequency of the IMF signal of the target sequence number value at all moments in the preset time domain of the target moment. Therefore, the degree of discreteness of the center frequency of the IMF signal of the target sequence number value at all moments in the preset time domain of the target moment can be analyzed to obtain the second abnormal coefficient of the IMF signal of the target sequence number value at the target moment.

[0068] Preferably, in one embodiment of the present invention, the standard deviation of the center frequency of the IMF signal of the target sequence value at all moments in the preset time domain of the target moment can be normalized, and the calculation result can be limited to the range of [0,1], so as to obtain the second abnormal coefficient of the IMF signal of the target sequence value at the target moment. In other embodiments of the present invention, statistics such as variance or range can also be used to realize the analysis of the degree of discreteness of the center frequency of the IMF signal of the target sequence value at all moments in the preset time domain of the target moment, which is not limited here.

[0069] Finally, the first abnormal coefficient and the second abnormal coefficient are combined to obtain the sawing abnormality index of the IMF signal with respect to the target sequence value at the target time.

[0070] As an example, in one embodiment of the present invention, the expression of the sawing anomaly index of the IMF signal with respect to the target sequence value at the target time may be specifically, for example, as follows:

[0071] P=norm(D+A)×norm(σ)

[0072] Among them, P represents the sawing anomaly index of the IMF signal of the target sequence value at the target moment; D represents the frequency bandwidth of the IMF signal of the target sequence value at the target moment; A represents the overall strength of the IMF signal of the target sequence value at the target moment; norm(D+A) represents the first anomaly coefficient of the IMF signal of the target sequence value at the target moment; σ represents the standard deviation of the center frequency of the IMF signal of the target sequence value at all moments in the preset time domain of the target moment; norm(σ) represents the second anomaly coefficient of the IMF signal of the target sequence value at the target moment; norm() represents the normalization function, which is used for normalization processing.

[0073] The same method as above can be used to obtain the sawing anomaly index of each IMF signal at the target moment and the sawing anomaly index of each IMF signal at each moment in the preset time period.

[0074] The adjustment weight analysis module 103 is used to obtain the interference index of the target moment based on the distribution of the sawing abnormality index of the IMF signal with the same serial number value at different moments in the preset time domain of the target moment, and the difference in the decomposition residual between the target moment and each moment in the preset time domain; and obtain the sawing speed adjustment weight of the current moment based on the distribution and change of the interference index at each moment in the preset time period, and the time series correlation between the interference index and the torque signal in the preset time period.

[0075] Variational mode decomposition is a signal decomposition performed based on the frequency range. Therefore, frequency differences between different IMF signals are normal, and thus different IMF signals have different abnormal performances for the sawing process. For example, the higher the frequency, the greater the reference value of the IMF component. Abnormal sawing of the workpiece causes the variational mode decomposition process to introduce additional vibration signals, thereby affecting the normal IMF signal decomposition, and thus destroying the stability of the IMF signal characteristics in the time series. If the IMF component signals at different moments in the time series maintain a high degree of normal sawing performance and have high similarity, then the IMF component at that moment belongs to normal variational mode decomposition, and the possibility of decomposition abnormality caused by sawing abnormality is small. Therefore, the embodiment of the present invention obtains the interference index at the target moment based on the distribution of sawing abnormality indicators of IMF signals with the same sequence value at different moments in the preset time domain at the target moment, and the difference in decomposition residuals between the target moment and each moment in the preset time domain. Subsequently, based on the interference indicators at each moment in the preset time period, the sawing speed adjustment weight at the current moment can be accurately calculated and analyzed, thereby achieving real-time adjustment of the sawing speed of the horizontal band saw.

[0076] Preferably, in one embodiment of the present invention, the method for obtaining the interference indicator at the target moment specifically includes:

[0077] First, a first interference coefficient at the target moment is obtained according to the distribution of sawing anomaly indicators of IMF signals with the same sequence number value at different moments in a preset time domain at the target moment.

[0078] Preferably, in one embodiment of the present invention, the method for obtaining the first interference coefficient at the target time specifically includes:

[0079] A straight line fitting is performed on the sawing anomaly indicators of the IMF signals with the same sequence number value at all moments in the preset time domain of the target moment, and the angle between the fitted straight line and the horizontal direction is used as the fluctuation degree of the IMF signal for each sequence number value at the target moment. In an embodiment of the present invention, the existing least squares method or other fitting methods can be used to implement straight line fitting, which is not limited here, and the range of the angle between the fitted straight line and the horizontal direction is 0 to 90 degrees. The greater the fluctuation degree, the worse the sawing stability exhibited by the IMF signals with the same sequence number value at all moments in the preset time domain of the target moment, and the greater the degree of interference at the target moment.

[0080] Then, the average value of the fluctuation degree of the IMF signal of all sequence values ​​at the target moment is used as the first interference coefficient at the target moment.

[0081] Then, the greater the difference between the decomposition residual at the target moment and the overall level of the decomposition residual at all moments in the preset time domain of the target moment, the more abnormal decomposition behavior there is in the variational mode decomposition performed at the target moment, and the greater the degree of interference at the target moment. Therefore, the absolute value of the difference between the average value of the decomposition residual at all moments in the preset time domain of the target moment and the decomposition residual at the target moment can be used as the numerator, the standard deviation of the decomposition residual at all moments in the preset time domain of the target moment can be used as the denominator, and the ratio can be used as the second interference coefficient at the target moment.

[0082] Then, the first interference coefficient and the second interference coefficient are combined to obtain the interference index at the target time.

[0083] As an example, in one embodiment of the present invention, the expression of the interference index at the target time may be specifically, for example, as follows:

[0084]

[0085] Among them, Q represents the interference index at the target time; θ n Indicates the fluctuation degree of the IMF signal with respect to the nth sequence value at the target time; represents the first interference coefficient at the target time; N represents the number of IMF signals corresponding to the target time; r represents the decomposition residual at the target time; represents the average value of the decomposition residuals of all moments in the preset time domain of the target moment; R represents the standard deviation of the decomposition residuals of all moments in the preset time domain of the target moment; Represents the second interference coefficient at the target time.

[0086] The interference index at each moment in the preset time period can be obtained by the same method as above. If the deviation between the overall level of the interference index at all moments in the preset time period and the interference index at the initial moment is greater, and the interference index in the preset time period changes more in time sequence, it means that there is an abnormality in the sawing process at the current moment. At this time, the sawing speed should be appropriately reduced to maintain the processing accuracy of the material sawing. At the same time, the load of the horizontal band saw can be reflected by the spindle torque. If the interference index and the torque signal show a strong correlation in time sequence, the adjustment range of the sawing speed should be smaller. On the contrary, if the correlation between the two is poor at this time, it means that the vibration and torque signals are contradictory, and a single adjustment will cause a reverse error and a parameter conflict. At this time, the sawing speed needs to be significantly reduced. Therefore, the distribution and changes of the interference indicators at each moment in the preset time period, as well as the time series correlation between the interference indicators and the torque signal in the preset time period can be analyzed. The obtained sawing speed adjustment weight reflects the degree to which the sawing speed at the current moment needs to be adjusted. Subsequently, the sawing speed of the horizontal band saw can be adjusted in real time through the sawing speed adjustment weight, thereby improving the control effect of the horizontal band saw.

[0087] Preferably, in one embodiment of the present invention, the method for obtaining the sawing speed adjustment weight at the current moment specifically includes:

[0088] First, the average value of the interference index at all moments in the preset time period is taken as the overall interference index of the preset time period, and the absolute value of the difference between the overall interference index and the interference index at the first moment in the preset time period is taken as the interference index deviation value at the current moment. The larger the interference index deviation value, the greater the degree of deviation between the overall level of the interference index at all moments in the preset time period and the interference index at the initial moment.

[0089] According to the difference between the interference indicators at two adjacent moments in the preset time period, the interference indicator variation degree at the current moment is obtained. The greater the interference indicator variation degree, the greater the temporal variation of the interference indicator in the preset time period.

[0090] Preferably, in one embodiment of the present invention, the method for obtaining the interference index change degree at the current moment specifically includes:

[0091] Any two adjacent moments within the preset time period are taken as an adjacent moment group, the absolute value of the difference between the interference indices of the two moments in each adjacent moment group is taken as the interference index change of each adjacent moment group, and the average value of the interference index change of all adjacent moment groups is taken as the interference index change degree of the current moment.

[0092] The interference index deviation value and the interference index variation are integrated to obtain a first adjustment evaluation value at the current moment. The larger the first adjustment evaluation value is, the greater the degree to which the sawing speed at the current moment needs to be adjusted.

[0093] As an example, in one embodiment of the present invention, the expression of the first adjustment evaluation value at the current moment may be specifically, for example, as follows:

[0094]

[0095] Wherein, E1 represents the first adjusted evaluation value at the current moment; Indicates the overall interference index of the preset time period; Q1 indicates the interference index of the first moment in the preset time period; Indicates the deviation value of the interference index at the current moment; ΔQ m represents the change in the interference index of the mth adjacent time group in the preset time period; represents the interference index change degree at the current moment; M represents the number of adjacent time groups.

[0096] Then, the interference indicators at all moments in the preset time period and the torque data of the torque signal at all moments are sorted in chronological order to obtain the interference indicator sequence and the torque sequence. The absolute value of the Pearson correlation coefficient between the interference indicator sequence and the torque sequence is negatively correlated to obtain the second adjustment evaluation value at the current moment. The larger the second adjustment evaluation value, the greater the degree of adjustment of the sawing speed at the current moment.

[0097] As an example, in one embodiment of the present invention, the expression of the second adjustment evaluation value at the current moment may be specifically, for example, as follows:

[0098]

[0099] Wherein, E2 represents the second adjustment evaluation value at the current moment; ρ represents the Pearson correlation coefficient between the interference index sequence and the torque sequence; ε represents a preset adjustment parameter used to prevent the denominator from being 0, and the value range of ε is [0.001, 0.01]. In one embodiment of the present invention, ε is set to 0.01. The specific value of ε can also be set by the implementer according to the specific implementation scenario and is not limited here.

[0100] It should be noted that in other embodiments of the present invention, negative correlation mapping may be achieved through other basic mathematical operations, which will not be described in detail here.

[0101] Finally, the first adjustment evaluation value and the second adjustment evaluation value are integrated and normalized, and the calculation result is limited to the range of [0, 1], so as to obtain the sawing speed adjustment weight at the current moment.

[0102] As an example, in one embodiment of the present invention, the expression for adjusting the sawing speed weight at the current moment may be specifically, for example:

[0103] U=tanh(E1+E2)

[0104] Among them, U represents the sawing speed adjustment weight at the current moment; E1 represents the first adjustment evaluation value at the current moment; E2 represents the second adjustment evaluation value at the current moment; tanh() represents the hyperbolic tangent function, which is used for normalization processing.

[0105] At this point, the sawing speed adjustment weight at the current moment is obtained, and the sawing speed at the current moment can be adjusted in real time based on the sawing speed adjustment weight.

[0106] The sawing speed adjustment module 104 is configured to adjust the sawing speed of the band saw in real time based on the sawing speed adjustment weight.

[0107] The greater the sawing speed adjustment weight at the current moment, the more it is necessary to reduce the sawing speed of the horizontal band saw machine to a greater extent to avoid abnormal sawing. Therefore, the sawing speed of the band saw machine can be adjusted in real time based on the sawing speed adjustment weight, thereby improving the control effect of the horizontal band saw machine.

[0108] Preferably, in one embodiment of the present invention, the method for obtaining the sawing speed adjustment weight at the current moment specifically includes:

[0109] The product of the sawing speed adjustment weight at the current moment and the standard sawing speed is used as the sawing speed adjustment amount at the current moment, and the difference between the standard sawing speed and the sawing speed adjustment amount at the current moment is used as the adjusted sawing speed at the current moment, wherein the standard sawing speed is a known value set before performing the sawing task.

[0110] As an example, in one embodiment of the present invention, the expression for adjusting the sawing speed at the current moment may be specifically, for example, as follows:

[0111] V ′ =VU×V

[0112] Among them, V ′ represents the current adjusted sawing speed; V represents the standard sawing speed; U represents the current sawing speed adjustment weight; U×V represents the current sawing speed adjustment amount.

[0113] It should be noted that the order in which the embodiments of the present invention are described above is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0114] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

Claims

1. A self-feeding horizontal band saw control system, characterized in that: The system comprises: A data acquisition module is used to obtain a vibration signal and a torque signal of the self-feeding horizontal band saw within a preset time period before a current moment; An anomaly analysis module is used to take any moment within a preset time period as a target moment, decompose the portion of the vibration signal within the preset time domain at the target moment, obtain the decomposition residual and multiple IMF signals at the target moment, and the center frequency, frequency bandwidth, and overall strength of each IMF signal; based on the center frequency, label all IMF signals at the target moment to obtain the sequence number value of each IMF signal at the target moment; obtain the sawing anomaly index of each IMF signal at the target moment based on the frequency bandwidth and overall strength of each IMF signal at the target moment, and the distribution of the center frequency of IMF signals with the same sequence number value at different moments in the preset time domain at the target moment; An adjustment weight analysis module is configured to obtain an interference index at a target moment based on the distribution of the sawing anomaly index of the IMF signal with the same sequence number value at different moments in a preset time domain at the target moment, and the difference in the decomposition residuals between the target moment and each moment in the preset time domain; and obtain a sawing speed adjustment weight at the current moment based on the distribution and change of the interference index at each moment in a preset time period, and the temporal correlation between the interference index and the torque signal in the preset time period; A sawing speed adjustment module, configured to adjust the sawing speed of the band saw in real time based on the sawing speed adjustment weight; The step of obtaining the sawing anomaly index of each IMF signal at the target time includes: Taking any sequence number value as the target sequence number value, integrating the frequency bandwidth and the overall strength of the IMF signal of the target sequence number value at the target time and performing normalization processing to obtain a first anomaly coefficient of the IMF signal with respect to the target sequence number value at the target time; Analyzing the degree of dispersion of the center frequency of the IMF signal of the target sequence value at all moments in the preset time domain at the target moment to obtain a second abnormal coefficient of the IMF signal of the target sequence value at the target moment; Combining the first abnormal coefficient and the second abnormal coefficient to obtain a sawing abnormality index of the IMF signal with respect to the target sequence value at the target time; The interference index for obtaining the target time includes: Obtaining a first interference coefficient at the target moment according to the distribution of the sawing abnormality indicator of the IMF signal with the same sequence number value at different moments in the preset time domain at the target moment; The absolute value of the difference between the average value of the decomposition residuals at all moments in the preset time domain of the target moment and the decomposition residuals at the target moment is used as the numerator, the standard deviation of the decomposition residuals at all moments in the preset time domain of the target moment is used as the denominator, and the ratio is used as the second interference coefficient at the target moment; The first interference coefficient and the second interference coefficient are combined to obtain an interference index at a target moment.

2. A self-feeding horizontal band saw control system according to claim 1, characterized in that: The obtaining of the second abnormal coefficient of the IMF signal of the target sequence value at the target time comprises: Normalize the standard deviation of the center frequency of the IMF signal of the target sequence value at all moments in the preset time domain at the target moment to obtain a second abnormal coefficient of the IMF signal about the target sequence value at the target moment.

3. The self-feeding horizontal band saw control system according to claim 1, characterized in that: The obtaining of the first interference coefficient at the target time comprises: Performing linear fitting on the sawing anomaly indicator of the IMF signal with the same sequence number value at all moments in the preset time domain at the target moment, and taking the angle between the fitted straight line and the horizontal direction as the fluctuation degree of the IMF signal for each sequence number value at the target moment; The average value of the fluctuation degree of the IMF signal of all sequence values ​​at the target moment is used as the first interference coefficient at the target moment.

4. The self-feeding horizontal band saw control system according to claim 1, characterized in that: The obtaining of the sawing speed adjustment weight at the current moment includes: Taking the average value of the interference index at all times within the preset time period as the overall interference index of the preset time period; The absolute value of the difference between the overall interference index and the interference index at the first moment in the preset time period is used as the interference index deviation value at the current moment; Obtaining a degree of change in the interference index at a current moment according to a difference in the interference index between two adjacent moments within a preset time period; Combining the interference indicator deviation value and the interference indicator change degree to obtain a first adjustment evaluation value at a current moment; sorting the interference indicators at all moments in a preset time period and the torque data of the torque signal at all moments in time in chronological order to obtain an interference indicator sequence and a torque sequence, performing negative correlation mapping on the absolute values ​​of the Pearson correlation coefficients between the interference indicator sequence and the torque sequence to obtain a second adjustment evaluation value at the current moment; The first adjustment evaluation value and the second adjustment evaluation value are integrated and normalized to obtain the sawing speed adjustment weight at the current moment.

5. The self-feeding horizontal band saw control system according to claim 4, characterized in that: Obtaining the interference index change degree at the current moment includes: Any two adjacent moments within a preset time period are regarded as an adjacent moment group, and the absolute value of the difference between the interference indicators of the two moments in each adjacent moment group is regarded as the interference indicator variation of each adjacent moment group; The average value of the interference index change amounts of all adjacent time groups is used as the interference index change degree at the current moment.

6. The self-feeding horizontal band saw control system according to claim 1, characterized in that: The real-time adjustment of the sawing speed of the band saw machine includes: The product of the sawing speed adjustment weight and the standard sawing speed at the current moment is used as the sawing speed adjustment amount at the current moment; The difference between the standard sawing speed and the sawing speed adjustment amount at the current moment is used as the adjusted sawing speed at the current moment.

7. The self-feeding horizontal band saw control system according to claim 1, characterized in that: The sequence number value of each IMF signal obtained at the target time includes: Using non-zero natural numbers, all IMF signals at the target time are numbered according to the ascending order of the center frequency to obtain the sequence number value of each IMF signal at the target time.

8. The self-feeding horizontal band saw control system according to claim 1, characterized in that: The obtaining of the decomposition residual and multiple IMF signals at the target time as well as the center frequency, frequency bandwidth and overall strength of each IMF signal includes: Using the variational mode decomposition algorithm, the vibration signal is decomposed in the preset time domain at the target time to obtain the decomposition residual and multiple IMF signals at the target time as well as the center frequency of each IMF signal; Perform frequency domain conversion on each IMF signal at the target moment to obtain the spectrum of each IMF signal at the target moment, and combine the spectrum of each IMF signal at the target moment to obtain the frequency bandwidth and overall strength of each IMF signal at the target moment.

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