Motor control method, device and system suitable for leather production

Abstract

The invention relates to the technical field of industrial motor control, in particular to a motor control method, device and system suitable for leather production, and the method comprises the steps: collecting motor parameters and historical leather edge thickness; selecting each sampling point, and calculating the inflection point possibility of each sampling point; dividing each cutting stage; acquiring a parameter fluctuation coefficient of each motor parameter at each acquisition moment based on a difference condition and a distance between each motor parameter and the motor parameter in the local neighborhood; on the basis of the parameter fluctuation coefficient and the difference condition between the torque and the rotating speed, acquiring a fluctuation optimization factor of each motor parameter at each acquisition moment; obtaining the cutting resistance degree of each cutting stage; the rotating speed optimal selection value and the primary selection rotating speed of each cutting stage are calculated; and the optimal rotating speeds of all the cutting stages in the current cutting process of the leather production cutter are obtained, and a leather production motor is controlled. The cutting efficiency and precision of leather production are improved.

Description

Technical Field

[0001] The present application relates to the field of industrial motor control technology, and in particular to a motor control method, device and system suitable for leather production. Background Art

[0002] Industrial controlled leather production is the denatured and non-perishable animal skin obtained through physical and chemical processing such as depilation and tanning. From raw leather to finished leather that meets product quality requirements, it needs to go through many complex chemical and mechanical treatments, usually after depilation, degreasing, disinfection and other treatments, and then soaked and cut.

[0003] Leather cutting is one of the most important links in leather production in industrial control systems. The existing leather cutting method usually uses a leather cutting machine to cut leather. In leather cutting machines, DC motors are usually used as power sources to provide power for the cutter. The speed of the DC motor in the industrial control system is a key parameter in leather production and cutting. Too high a speed may cause damage to the leather surface or uneven cutting, and too low a speed may result in low cutting efficiency. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide a motor control method, device and system suitable for leather production. The technical solutions adopted are as follows:

[0005] In a first aspect, an embodiment of the present application provides a motor control method suitable for leather production, the method comprising the following steps:

[0006] Collecting motor parameters at each collection moment in the historical leather production and cutting process and the historical leather edge thickness; the motor parameters include speed and torque;

[0007] Select sampling points at equal intervals on the preset tool movement curve of the leather cutting machine, and obtain the possibility of the inflection point of each sampling point based on the difference in the slope of the connection line between each sampling point and its adjacent sampling point; divide the cutting process of each leather production tool into cutting stages according to the possibility of the inflection point;

[0008] Based on the difference and distance between each motor parameter and its motor parameter in the local neighborhood, the parameter fluctuation coefficient of each motor parameter at each acquisition moment is obtained; based on the parameter fluctuation coefficient and the difference between the torque and the speed, the volatility optimization factor of each motor parameter at each acquisition moment is obtained;

[0009] Based on the parameter fluctuation coefficient, the fluctuation optimization factor and the average discrete degree of the historical leather edge thickness, the cutting resistance degree of each cutting stage is obtained;

[0010] Based on the frequency of speed occurrence and cutting resistance, the preferred speed value and preliminary speed of each cutting stage are obtained; based on the difference between cutting resistance and the preferred speed value and preliminary speed, the optimal speed of all cutting stages in the current leather production tool cutting process is obtained to control the leather production motor.

[0011] Furthermore, the method for obtaining the possibility of the inflection point is:

[0012] Connect each sampling point with its previous adjacent sampling point to obtain the front adjacent straight line of each sampling point, connect each sampling point with its subsequent adjacent sampling point to obtain the back adjacent straight line of each sampling point, and calculate the slopes of the front adjacent straight line and the back adjacent straight line of each sampling point;

[0013] For each sampling point, the absolute value of the difference between the slopes of the preceding and succeeding adjacent straight lines of the sampling point is calculated, and the ratio of the absolute value of the difference to the maximum absolute value of the slopes of the preceding and succeeding adjacent straight lines of the sampling point is taken as the inflection point possibility of each sampling point.

[0014] Further, the acquisition method of each cutting stage is:

[0015] The sampling points are clustered using a clustering algorithm, and the distance metric is the difference between the possibilities of the inflection points, and two clusters are obtained;

[0016] For each cluster, calculate the mean of the inflection point likelihood of all sampling points in the cluster, and take all sampling points in the cluster with the largest mean as inflection points;

[0017] All inflection points are sorted according to the order in which the tool reaches the inflection point position. The cutting process between the starting point and the first inflection point is regarded as the first cutting stage, and the cutting process between the first inflection point and the second inflection point is regarded as the second cutting stage. Similarly, the leather production tool cutting process is divided into various cutting stages.

[0018] Further, the method for obtaining the parameter fluctuation coefficient is:

[0019] For each motor parameter in each cutting stage, a neighborhood with a radius of a preset length is divided with each motor parameter as the center;

[0020] The calculation formula of parameter fluctuation coefficient is: Wherein, B is the parameter fluctuation coefficient of each motor parameter at each acquisition time; Z is the Z score of all motor parameter values ​​in its neighborhood at each acquisition time for each motor parameter; tot is the total number of motor parameters in the neighborhood of the motor parameter at each acquisition time for each motor parameter; ω is the data value of the motor parameter at each acquisition time; ω r is the value of the rth motor parameter in the neighborhood of the motor parameter at each acquisition moment, d rIt is the absolute value of the difference between the motor parameter at each acquisition time and the acquisition time of the rth motor parameter in its neighborhood.

[0021] Furthermore, the calculation formula of the volatility optimization factor is: Where Y is the volatility optimization factor of the motor parameters at each acquisition time, totm is the minimum value of the total number of motor parameters in the neighborhood of the motor parameters at each acquisition time for each motor parameter, ω is the speed parameter value at each acquisition time, F is the torque parameter value at each acquisition time, ω r is the rth speed parameter value in the neighborhood of the speed at each acquisition time, F r is the rth torque parameter value in the neighborhood of the torque at each acquisition moment, B ω is the parameter fluctuation coefficient of the speed parameter at each acquisition moment, B F is the parameter fluctuation coefficient of the torque parameter at each acquisition moment, and ε is the preset parameter adjustment factor.

[0022] Further, the method for obtaining the cutting resistance is:

[0023] For each acquisition moment, the product of the parameter fluctuation coefficient of the speed parameter at each acquisition moment and the volatility optimization factor is used as the optimized fluctuation coefficient of the speed parameter at each acquisition moment;

[0024] For each cutting stage, the sum of the optimized fluctuation coefficients of the rotation speed parameters at all sampling moments in the cutting stage is calculated, and the product of the variance of the historical leather edge thickness of all sampling points on the edge of the leather product in the cutting stage and the sum is used as the cutting resistance of each cutting stage.

[0025] Furthermore, the method for obtaining the preferred speed value and the preliminary speed is as follows:

[0026] For each cutting stage in each historical leather product production cutting process, the rotation speed parameter that appears most frequently in the same cutting stage in all historical leather product production cutting processes is used as the characteristic rotation speed of each cutting stage;

[0027] For the characteristic rotation speed of each cutting stage, obtain the frequency of the characteristic rotation speed appearing in the characteristic rotation speed of the same cutting stage in all historical leather product production cutting processes, calculate the sum of the cutting resistance of the same cutting stage in all historical leather product production cutting processes, and use the ratio of the frequency to the sum as the preferred rotation speed value of the characteristic rotation speed of each cutting stage;

[0028] For the preferred speed value of the characteristic speed of each cutting stage in the current leather production tool cutting process, the characteristic speed with the largest preferred speed value for the same cutting stage in all historical leather product production cutting processes is used as the preliminary selected speed for each cutting stage in the current leather production tool cutting process.

[0029] Furthermore, the method for obtaining the optimal speed is:

[0030] The initially selected rotation speed in the first cutting stage of the current leather production knife cutting process is taken as the optimal rotation speed;

[0031] Randomly select a historical leather product production cutting process from the historical leather product production cutting process with the same initial rotation speed and the same cutting stage as the current leather production tool cutting process as the historical leather product production cutting process corresponding to each cutting stage of the current leather production tool cutting process;

[0032] Based on the cutting resistance, the cutting approximation of each cutting stage in the current leather production tool cutting process is obtained. The calculation formula is: Where S is the cutting approximation of the Pth cutting stage in the current leather production tool cutting process; P is the number of cutting stages that have been completed in the current leather production tool cutting process, G p It indicates the cutting resistance degree of the pth cutting stage in the current leather production tool cutting process. It represents the cutting resistance of the pth cutting stage in the historical leather product production cutting process corresponding to the current leather production tool cutting process;

[0033] Calculate the sum of the cutting approximations of the cutting stages in all historical leather production tool cutting processes that are the same as the cutting stages in the current leather production tool cutting process; multiply the preferred rotation speed value of each cutting stage in the current leather production tool cutting process by the summed result as the optimized rotation speed preferred value of each cutting stage in the current leather production tool cutting process;

[0034] For each cutting stage in the current leather production tool cutting process, the characteristic speed of the cutting stage with the largest preferred value of the optimized speed among the cutting stages in the same stage as each cutting stage in all historical leather production tool cutting processes is selected as the optimal speed for each cutting stage in the current leather production tool cutting process.

[0035] In a second aspect, an embodiment of the present application provides a motor control device suitable for leather production, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein when the processor executes the computer program, the steps of a motor control method suitable for leather production described in any one of the above items are implemented.

[0036] In a third aspect, an embodiment of the present application provides a motor control system adapted for leather production, the system comprising:

[0037] A data acquisition module is used to collect motor parameters at each acquisition moment in the historical leather production and cutting process and the historical leather edge thickness; the motor parameters include rotation speed and torque;

[0038] A cutting resistance acquisition module is used to select sampling points at equal intervals on a preset tool movement curve of a leather cutting machine, and obtain the possibility of an inflection point of each sampling point based on the difference in the slope of the line between each sampling point and its adjacent sampling point; divide the cutting process of each leather production tool into cutting stages according to the possibility of the inflection point; obtain the parameter fluctuation coefficient of each motor parameter at each collection moment based on the difference and distance between each motor parameter and its motor parameter in a local neighborhood; obtain the volatility optimization factor of each motor parameter at each collection moment based on the parameter fluctuation coefficient and the difference between torque and speed; obtain the cutting resistance of each cutting stage based on the parameter fluctuation coefficient, the volatility optimization factor and the average discrete degree of the historical leather edge thickness;

[0039] The industrial leather production motor control module is used to obtain the preferred speed value and preliminary speed of each cutting stage based on the frequency of speed occurrence and cutting resistance; based on the difference between cutting resistance and the preferred speed value and preliminary speed, the optimal speed of all cutting stages in the current leather production tool cutting process is obtained to control the leather production motor.

[0040] This application has at least the following beneficial effects:

[0041] In the present application, leather cutting is adaptively divided according to the characteristics of the fixed movement curve of the tool in the leather product production process of the industrial control system. In the process of industrial controlled leather product production, different cutting stages are obtained, and the cutting process of the industrial controlled leather production tool is analyzed more accurately, so as to more accurately control the motor of the industrial control system. The parameter fluctuation coefficient and the volatility optimization factor are adaptively constructed through the motor parameters in the cutting stage of the historical cutting process and the parameters after the leather product production, which reflects the volatility of the motor parameters in the industrial controlled leather production tool cutting process, and the volatility is optimized to obtain the optimized fluctuation coefficient, and the acquisition of the optimized motor parameter volatility is completed. Based on the optimized motor parameter volatility and the parameter changes after the leather product production, the cutting resistance is adaptively constructed, and the resistance of the motor in the leather production tool cutting process is simultaneously reflected while considering the motor parameter volatility. Based on the cutting resistance and the frequency of the historical motor cutting, the preferred value of the motor speed in different cutting stages is adaptively constructed to complete the acquisition of the optimal speed of the motor, so that the motor of the industrial control system can reach the optimal speed according to the actual cutting situation at different cutting stages, thereby improving the cutting efficiency and accuracy of the industrial controlled leather production. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 A flowchart of a motor control method suitable for leather production provided in one embodiment of the present application;

[0044] Figure 2 A flow chart for obtaining cutting resistance provided for one embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of the motor control method, device and system suitable for leather production proposed in accordance with the present application, its specific implementation, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[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 application belongs.

[0047] The following is a detailed description of a specific scheme of a motor control method, device and system suitable for leather production provided by the present application in conjunction with the accompanying drawings.

[0048] See also Figure 1 , which shows a flow chart of a motor control method suitable for leather production provided by an embodiment of the present application, the method comprising the following steps:

[0049] Step S001, collecting motor parameters at each collection moment in the historical leather production and cutting process and the historical leather edge thickness.

[0050] Industrial controlled leather production cutting is usually for producing corresponding leather products. When leather products are cut using a leather cutting machine, the movement trajectory of the tool is usually fixed.

[0051] In the production and cutting process of historical leather products in the industrial control system, the parameters of the motor at each acquisition moment are obtained, including the speed and torque of the motor, and the edge thickness of the leather product after cutting is obtained using an ultrasonic thickness gauge.

[0052] At this point, the motor parameters of the industrial control system and the historical leather edge cutting thickness are obtained.

[0053] Step S002, selecting sampling points at equal intervals on the preset tool movement curve of the leather cutting machine, and obtaining the possibility of the inflection point of each sampling point based on the difference in the slope of the line between each sampling point and its adjacent sampling points; dividing the cutting process of each leather production tool into cutting stages according to the inflection point possibility; obtaining the parameter fluctuation coefficient of each motor parameter at each collection moment based on the difference and distance between each motor parameter and its motor parameter in the local neighborhood; obtaining the volatility optimization factor of each motor parameter at each collection moment based on the parameter fluctuation coefficient and the difference between the torque and the speed; obtaining the cutting resistance of each cutting stage based on the parameter fluctuation coefficient, the volatility optimization factor and the average discrete degree of the historical leather edge thickness.

[0054] When the leather cutting machine of the industrial control system cuts leather, the tool movement trajectory of the same leather product is the same, and different parts of the leather may have different physical properties, such as elasticity and hardness, which will directly affect the resistance of the tool during cutting. Between the two inflection points, the movement direction of the tool is close. When moving along a fixed direction, its elasticity and hardness change less, and the resistance encountered by the tool during cutting changes less. Therefore, this embodiment analyzes the tool movement curve. Among them, the tool movement curve of the leather cutting machine is fixed, and the acquisition method is not repeated in this embodiment.

[0055] K equally spaced sampling points are selected on the tool movement curve. In this embodiment, the value is K=200, and the implementer may select the sampling points according to the actual situation.

[0056] The sampling points are sorted in the order in which the tool reaches the sampling point position on the tool movement curve, each sampling point is connected with its previous adjacent sampling point to obtain the front adjacent straight line of each sampling point, and each sampling point is connected with its previous adjacent sampling point to obtain the back adjacent straight line of each sampling point, and the slopes of the front adjacent straight line and the back adjacent straight line of each sampling point are calculated.

[0057] For each sampling point, the corresponding inflection point possibility is obtained, and the calculation formula is: Where U is the inflection point probability of each sampling point; K1 is the slope of the straight line connecting the sampling point with the previous sampling point, and K2 is the slope of the straight line connecting the sampling point with the next sampling point. max() means selecting the maximum value.

[0058] It should be noted that, in the above formula, the greater the change in slope, the greater the change in direction of the local data of the sampling point, and the more likely the sampling point is to be an inflection point; conversely, the less likely the sampling point is to be an inflection point; wherein the denominator selects the maximum value of |K1|, |K2| to ensure that the value of the inflection point possibility is between 0 and 1.

[0059] At this point, the inflection point probability of each sampling point is obtained.

[0060] The sampling points are clustered by the K-means mean clustering algorithm, where the number of cluster categories is set to 2, the distance metric is the absolute value of the difference between the inflection point possibilities, and the initial cluster center point is randomly selected. The K-means mean clustering algorithm and the clustering process are well-known technologies and will not be described here. The sampling points can be divided into two categories, which are respectively recorded as the first category and the second category. If the average inflection point possibility of the sampling points in the first category is greater than the average inflection point possibility of the sampling points in the second category, the sampling points in the first category are inflection points.

[0061] At this point, the inflection point detection of the tool movement process is completed. The inflection points are also sorted according to the order in which the tool cutting reaches the inflection point position. The cutting process between the starting point and the first inflection point is taken as the first cutting stage, and the cutting process between the first inflection point and the second inflection point is taken as the second cutting stage. And so on, the leather production tool cutting process is divided into various cutting stages.

[0062] At this point, the leather production tool cutting process is divided into various cutting stages.

[0063] Furthermore, the greater the change in the elasticity and hardness of the leather during the production and cutting of leather products, the greater the cutting resistance. Therefore, for different cutting stages, the cutting resistance of each cutting stage is adaptively constructed according to the fluctuations in the motor parameters in the historical production process and the changes in the edge thickness of the leather products actually produced.

[0064] First, the volatility of each motor parameter is obtained, and each motor parameter in each cutting stage is analyzed.

[0065] For each motor parameter in each cutting stage, a neighborhood with a radius of R is divided with each motor parameter as the center. In this embodiment, the value of R is 10, and the implementer can select it according to the actual situation.

[0066] Specifically, in order to reflect the fluctuation degree of each motor parameter at each collection time in each cutting stage, based on the difference and distance between the motor parameters, for each motor parameter, the parameter fluctuation coefficient of the motor parameter at each collection time is constructed, and the calculation formula is: Wherein, B is the parameter fluctuation coefficient of each motor parameter at each acquisition moment; Z is the Z score of all motor parameter values ​​in its neighborhood at each acquisition moment for each motor parameter, which reflects the deviation of the overall distribution of the data points of each motor parameter in its neighborhood; tot is the total number of motor parameters in the neighborhood of the motor parameter at each acquisition moment for each motor parameter; ω is the data value of the motor parameter at each acquisition moment; ω r is the value of the rth motor parameter in the neighborhood of the motor parameter at each acquisition moment, d r is the absolute value of the difference between the motor parameter at each acquisition time and the acquisition time of the rth motor parameter in its neighborhood. The calculation method of the Z score is a well-known technology and will not be described here.

[0067] Among them, the greater the local change of the motor parameter value during the cutting process, the greater the change in the elasticity and hardness of the leather surface during the cutting process of leather product production, the greater the degree of noise interference at this time, and the greater the volatility of each motor parameter, that is, the greater the value of the parameter fluctuation coefficient of each motor parameter; conversely, the smaller the value of the parameter fluctuation coefficient of each motor parameter.

[0068] Since the working environment of the motor of the leather cutting machine is relatively complex, it is very easy to be interfered by noise when collecting the corresponding motor parameter data, resulting in low motor parameter accuracy, which in turn makes the construction of motor parameter volatility inaccurate.

[0069] The motor cutting machine usually works with a fixed preset power, and the power of the motor is usually equal to the multiplication of the motor torque and the speed. Therefore, when the motor speed fluctuates, the motor torque must also fluctuate accordingly. Therefore, this application optimizes the volatility of the motor parameters based on the correlation between the motor parameters, that is, according to the speed and torque, a volatility optimization factor is constructed, and the calculation formula is: Where Y is the volatility optimization factor of the motor parameters at each acquisition time, totm is the minimum value of the total number of motor parameters in the neighborhood of the motor parameters at each acquisition time for each motor parameter, ω is the speed parameter value at each acquisition time, F is the torque parameter value at each acquisition time, ω r is the rth speed parameter value in the neighborhood of the speed at each acquisition time, F r is the rth torque parameter value in the neighborhood of the torque at each acquisition moment, B ω is the parameter fluctuation coefficient of the speed parameter at each acquisition moment, B F is the parameter fluctuation coefficient of the torque parameter at each acquisition moment, ε is the preset parameter adjustment factor to prevent the denominator from being zero, and in this embodiment, the value is 1.

[0070] It should be noted that the volatility of the motor parameters is optimized by the difference between the speed parameters and the torque parameters at each acquisition moment. The greater the difference between the speed parameters and the torque parameters at each acquisition moment, the smaller the difference between the parameter fluctuation coefficients, which means that the speed fluctuation of the speed data point has a greater impact on the torque parameter, and the greater the volatility optimization factor at this time; otherwise, the smaller the volatility optimization factor.

[0071] Furthermore, the parameter fluctuation coefficient of each motor parameter in each cutting stage at each collection moment is optimized according to the volatility optimization factor. For each collection moment, the product of the parameter fluctuation coefficient of each motor parameter at each collection moment and the volatility optimization factor is used as the optimized fluctuation coefficient of each motor parameter at each collection moment.

[0072] At this point, the optimized fluctuation coefficient of each motor parameter at each acquisition time is obtained.

[0073] Furthermore, the cutting resistance of each cutting stage is calculated according to the optimized fluctuation coefficient of the rotation speed parameter at each collection moment and the historical leather edge thickness. The calculation method is as follows: for each cutting stage, the sum of the optimized fluctuation coefficients of the rotation speed parameter at all collection moments in the cutting stage is calculated, and the product of the variance of the historical leather edge thickness of all sampling points on the edge of the leather product in the cutting stage and the sum is used as the cutting resistance of each cutting stage. The flow chart for obtaining the cutting resistance is shown in FIG. Figure 2 shown.

[0074] The larger the optimization fluctuation coefficient, the greater the change in the elasticity and hardness of the leather during the production and cutting of leather products, the greater the cutting resistance; the larger the variance of the historical leather edge thickness, the greater the change in hardness during the production and cutting of leather products, and the greater the cutting resistance; conversely, the smaller the cutting resistance.

[0075] Step S003, based on the frequency of the speed and the cutting resistance, the preferred speed value and the preliminary speed of each cutting stage are obtained; based on the difference between the cutting resistance and the preferred speed value and the preliminary speed, the optimal speed of all cutting stages in the current leather production tool cutting process is obtained to control the leather production motor.

[0076] According to the above steps, the construction of the cutting resistance at each cutting stage in each historical production process of leather products is completed. When the efficiency and accuracy during cutting are low, the rotation speed at this time should not be the optimal value. Therefore, the motor speed parameters and cutting resistance corresponding to the cutting stage of the historical production process are used to construct the optimal value of the motor speed, and then the optimal speed of the motor at different cutting stages in the current leather product cutting process is obtained.

[0077] For each cutting stage in each historical leather product production cutting process, the rotation speed parameter that appears most frequently in the same cutting stage in all historical leather product production cutting processes is used as the characteristic rotation speed of each cutting stage.

[0078] For the characteristic rotational speed of each cutting stage, obtain the frequency of the characteristic rotational speed in the characteristic rotational speed of the same cutting stage in all historical leather product production cutting processes, and calculate the sum of the cutting resistance of the same cutting stage in all historical leather product production cutting processes, and use the ratio of the frequency to the summation result as the preferred rotational speed value of the characteristic rotational speed of each cutting stage.

[0079] It should be noted that the greater the cutting resistance, the lower the efficiency and accuracy of cutting at the current rotation speed, and the smaller the preferred value of the rotation speed; otherwise, the larger the preferred value of the rotation speed.

[0080] At this point, the setting of the optimal value of the characteristic speed of each cutting stage is completed.

[0081] Furthermore, for the preferred speed value of the characteristic speed at each cutting stage in the current leather production tool cutting process, the characteristic speed with the largest preferred speed value in each cutting stage in all historical leather product production cutting processes is used as the preliminary selected speed for each cutting stage in the current leather production tool cutting process.

[0082] Furthermore, from the historical leather product production cutting processes in which the cutting stages have the same initial rotation speed and the same cutting stage as the current leather production tool cutting process, a historical leather product production cutting process is randomly selected as the corresponding historical leather product production cutting process of the current leather production tool cutting process.

[0083] Furthermore, when optimizing the rotation speed of the subsequent cutting stage, it is necessary to consider the situation of the previous cutting stage in the leather production tool cutting process, and obtain the preliminary rotation speed of the subsequent cutting stage according to the situation of the previous cutting stage. Therefore, based on the difference between the cutting resistance of each cutting stage and the cutting resistance of the previous cutting stage, the cutting approximation of each cutting stage in the current leather production tool cutting process is obtained, and the calculation formula is: Where S is the cutting approximation of the Pth cutting stage in the current leather production tool cutting process; P is the number of cutting stages that have been completed in the current leather production tool cutting process, G p It indicates the cutting resistance degree of the pth cutting stage in the current leather production tool cutting process. It represents the cutting resistance of the pth cutting stage in the historical leather product production cutting process corresponding to the current leather production tool cutting process.

[0084] It should be noted that the greater the difference between the cutting resistance in the cutting stage of the current leather production tool cutting process and the cutting resistance in the cutting stage of the corresponding historical leather product production cutting process, the greater the difference in materials, and the smaller the impact weight corresponding to the historical leather product production cutting; conversely, the smaller the impact weight corresponding to the historical leather product production cutting.

[0085] At this point, the cutting approximation of each cutting stage of the current leather production tool cutting process is obtained.

[0086] The cutting speed of each cutting stage in the current leather production tool cutting process is optimized by cutting approximation, and the optimal value of the optimized speed is obtained. The calculation formula is: H ′ =H*S; where H ′is the optimized rotation speed preferred value of each cutting stage in the current leather production tool cutting process, H is the optimized rotation speed preferred value of each cutting stage in the current leather production tool cutting process, and S represents the sum of the cutting similarities of the cutting stages in all historical leather production tool cutting processes that are the same as the cutting stages in the current leather production tool cutting process.

[0087] Furthermore, for each cutting stage in the current leather production tool cutting process, the characteristic speed of the cutting stage with the largest preferred value of the optimized speed among the cutting stages that are at the same stage as each cutting stage in all historical leather production tool cutting processes is selected as the optimal speed for each cutting stage in the current leather production tool cutting process.

[0088] The characteristic speed corresponding to the optimized maximum speed preferred value is selected as the optimal speed of the motor in each cutting stage during the current leather production tool cutting process.

[0089] At this point, the optimal rotation speed of all cutting stages in the current leather production tool cutting process is obtained, so that the motor completes the cutting of the leather cutting stage at the optimal rotation speed.

[0090] Based on the same inventive concept as the above method, an embodiment of the present application also provides a motor control device suitable for leather production, including a memory, a processor, and a computer program stored in the memory and running on the processor, and when the processor executes the computer program, the steps of any one of the above-mentioned motor control methods suitable for leather production are implemented.

[0091] Similarly, based on the same inventive concept as the above method, the embodiment of the present application provides a motor control system suitable for leather production, the system comprising:

[0092] A data acquisition module is used to collect motor parameters at each acquisition moment in the historical leather production and cutting process and the historical leather edge thickness; the motor parameters include rotation speed and torque;

[0093] A cutting resistance acquisition module is used to select sampling points at equal intervals on a preset tool movement curve of a leather cutting machine, and obtain the possibility of an inflection point of each sampling point based on the difference in the slope of the line between each sampling point and its adjacent sampling point; divide the cutting process of each leather production tool into cutting stages according to the possibility of the inflection point; obtain the parameter fluctuation coefficient of each motor parameter at each collection moment based on the difference and distance between each motor parameter and its motor parameter in a local neighborhood; obtain the volatility optimization factor of each motor parameter at each collection moment based on the parameter fluctuation coefficient and the difference between torque and speed; obtain the cutting resistance of each cutting stage based on the parameter fluctuation coefficient, the volatility optimization factor and the average discrete degree of the historical leather edge thickness;

[0094] The industrial leather production motor control module is used to obtain the preferred speed value and preliminary speed of each cutting stage based on the frequency of speed occurrence and cutting resistance; based on the difference between cutting resistance and the preferred speed value and preliminary speed, the optimal speed of all cutting stages in the current leather production tool cutting process is obtained to control the leather production motor.

[0095] It should be noted that the above sequence of the embodiments of the present application is for description only and does not represent the advantages and disadvantages of the embodiments. The above is a description of a specific embodiment of this specification. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0096] The various embodiments in the present application are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0097] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application should be included in the protection scope of the present application.

Claims

1. A motor control method suitable for leather production, characterized in that: The method comprises the following steps: Collecting motor parameters at each collection moment in the historical leather production and cutting process and the historical leather edge thickness; the motor parameters include speed and torque; Select sampling points at equal intervals on the preset tool movement curve of the leather cutting machine, and obtain the possibility of the inflection point of each sampling point based on the difference in the slope of the connection line between each sampling point and its adjacent sampling point; divide the cutting process of each leather production tool into cutting stages according to the possibility of the inflection point; Based on the difference and distance between each motor parameter and its motor parameter in the local neighborhood, the parameter fluctuation coefficient of each motor parameter at each acquisition moment is obtained; based on the parameter fluctuation coefficient and the difference between the torque and the speed, the volatility optimization factor of each motor parameter at each acquisition moment is obtained; Based on the parameter fluctuation coefficient, the fluctuation optimization factor and the average discrete degree of the historical leather edge thickness, the cutting resistance degree of each cutting stage is obtained; Based on the frequency of speed occurrence and cutting resistance, the preferred speed value and preliminary speed of each cutting stage are obtained; based on the difference between cutting resistance and the preferred speed value and preliminary speed, the optimal speed of all cutting stages in the current leather production tool cutting process is obtained to control the leather production motor.

2. A motor control method suitable for leather production as claimed in claim 1, characterized in that: The method for obtaining the possibility of the inflection point is: Connect each sampling point with its previous adjacent sampling point to obtain the front adjacent straight line of each sampling point, connect each sampling point with its subsequent adjacent sampling point to obtain the back adjacent straight line of each sampling point, and calculate the slopes of the front adjacent straight line and the back adjacent straight line of each sampling point; For each sampling point, the absolute value of the difference between the slopes of the preceding and succeeding adjacent straight lines of the sampling point is calculated, and the ratio of the absolute value of the difference to the maximum absolute value of the slopes of the preceding and succeeding adjacent straight lines of the sampling point is taken as the inflection point possibility of each sampling point.

3. A motor control method suitable for leather production as claimed in claim 1, characterized in that: The acquisition method of each cutting stage is: The sampling points are clustered using a clustering algorithm, and the distance metric is the difference between the possibilities of the inflection points, and two clusters are obtained; For each cluster, calculate the mean of the inflection point likelihood of all sampling points in the cluster, and take all sampling points in the cluster with the largest mean as inflection points; All inflection points are sorted according to the order in which the tool reaches the inflection point position. The cutting process between the starting point and the first inflection point is regarded as the first cutting stage, and the cutting process between the first inflection point and the second inflection point is regarded as the second cutting stage. Similarly, the leather production tool cutting process is divided into various cutting stages.

4. A motor control method suitable for leather production as claimed in claim 1, characterized in that: The method for obtaining the parameter fluctuation coefficient is: For each motor parameter in each cutting stage, a neighborhood with a radius of a preset length is divided with each motor parameter as the center; The calculation formula of parameter fluctuation coefficient is: Wherein, B is the parameter fluctuation coefficient of each motor parameter at each acquisition time; Z is the Z score of all motor parameter values ​​in its neighborhood at each acquisition time for each motor parameter; tot is the total number of motor parameters in the neighborhood of the motor parameter at each acquisition time for each motor parameter; ω is the data value of the motor parameter at each acquisition time; ω r is the value of the rth motor parameter in the neighborhood of the motor parameter at each acquisition moment, d r It is the absolute value of the difference between the motor parameter at each acquisition time and the acquisition time of the rth motor parameter in its neighborhood.

5. A motor control method suitable for leather production as claimed in claim 1, characterized in that: The calculation formula of the volatility optimization factor is: Where Y is the volatility optimization factor of the motor parameters at each acquisition time, totm is the minimum value of the total number of motor parameters in the neighborhood of the motor parameters at each acquisition time for each motor parameter, ω is the speed parameter value at each acquisition time, F is the torque parameter value at each acquisition time, ω r is the rth speed parameter value in the neighborhood of the speed at each acquisition time, F r is the rth torque parameter value in the neighborhood of the torque at each acquisition moment, B ω is the parameter fluctuation coefficient of the speed parameter at each acquisition moment, B F is the parameter fluctuation coefficient of the torque parameter at each acquisition moment, and ε is the preset parameter adjustment factor.

6. A motor control method suitable for leather production as claimed in claim 1, characterized in that: The method for obtaining the cutting resistance is: For each acquisition moment, the product of the parameter fluctuation coefficient of the speed parameter at each acquisition moment and the volatility optimization factor is used as the optimized fluctuation coefficient of the speed parameter at each acquisition moment; For each cutting stage, the sum of the optimized fluctuation coefficients of the rotation speed parameters at all sampling moments in the cutting stage is calculated, and the product of the variance of the historical leather edge thickness of all sampling points on the edge of the leather product in the cutting stage and the sum is used as the cutting resistance of each cutting stage.

7. A motor control method suitable for leather production as claimed in claim 1, characterized in that: The method for obtaining the preferred speed value and the preliminary speed is as follows: For each cutting stage in each historical leather product production cutting process, the rotation speed parameter that appears most frequently in the same cutting stage in all historical leather product production cutting processes is used as the characteristic rotation speed of each cutting stage; For the characteristic rotation speed of each cutting stage, obtain the frequency of the characteristic rotation speed appearing in the characteristic rotation speed of the same cutting stage in all historical leather product production cutting processes, calculate the sum of the cutting resistance of the same cutting stage in all historical leather product production cutting processes, and use the ratio of the frequency to the sum as the preferred rotation speed value of the characteristic rotation speed of each cutting stage; For the preferred speed value of the characteristic speed of each cutting stage in the current leather production tool cutting process, the characteristic speed with the largest preferred speed value for the same cutting stage in all historical leather product production cutting processes is used as the preliminary selected speed for each cutting stage in the current leather production tool cutting process.

8. A motor control method suitable for leather production as claimed in claim 1, characterized in that: The method for obtaining the optimal speed is: The initially selected rotation speed in the first cutting stage of the current leather production knife cutting process is taken as the optimal rotation speed; Randomly select a historical leather product production cutting process from the historical leather product production cutting process with the same initial rotation speed and the same cutting stage as the current leather production tool cutting process as the historical leather product production cutting process corresponding to each cutting stage of the current leather production tool cutting process; Based on the cutting resistance, the cutting approximation of each cutting stage in the current leather production tool cutting process is obtained. The calculation formula is: Where S is the cutting approximation of the Pth cutting stage in the current leather production tool cutting process; P is the number of cutting stages that have been completed in the current leather production tool cutting process, G p It indicates the cutting resistance degree of the pth cutting stage in the current leather production tool cutting process. It represents the cutting resistance of the pth cutting stage in the historical leather product production cutting process corresponding to the current leather production tool cutting process; Calculate the sum of the cutting approximations of the cutting stages in all historical leather production tool cutting processes that are the same as the cutting stages in the current leather production tool cutting process; multiply the preferred rotation speed value of each cutting stage in the current leather production tool cutting process by the summed result as the optimized rotation speed preferred value of each cutting stage in the current leather production tool cutting process; For each cutting stage in the current leather production tool cutting process, the characteristic speed of the cutting stage with the largest preferred value of the optimized speed among the cutting stages in the same stage as each cutting stage in all historical leather production tool cutting processes is selected as the optimal speed for each cutting stage in the current leather production tool cutting process.

9. A motor control device adapted for leather production, 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 steps of a motor control method suitable for leather production as described in any one of claims 1-8 are implemented.

10. A motor control system suitable for leather production, characterized in that: The control system comprises: A data acquisition module is used to collect motor parameters at each acquisition moment in the historical leather production and cutting process and the historical leather edge thickness; the motor parameters include rotation speed and torque; A cutting resistance acquisition module is used to select sampling points at equal intervals on a preset tool movement curve of a leather cutting machine, and obtain the possibility of an inflection point of each sampling point based on the difference in the slope of the line between each sampling point and its adjacent sampling point; divide the cutting process of each leather production tool into cutting stages according to the possibility of the inflection point; obtain the parameter fluctuation coefficient of each motor parameter at each collection moment based on the difference and distance between each motor parameter and its motor parameter in a local neighborhood; obtain the volatility optimization factor of each motor parameter at each collection moment based on the parameter fluctuation coefficient and the difference between torque and speed; obtain the cutting resistance of each cutting stage based on the parameter fluctuation coefficient, the volatility optimization factor and the average discrete degree of the historical leather edge thickness; The industrial leather production motor control module is used to obtain the preferred speed value and preliminary speed of each cutting stage based on the frequency of speed occurrence and cutting resistance; based on the difference between cutting resistance and the preferred speed value and preliminary speed, the optimal speed of all cutting stages in the current leather production tool cutting process is obtained to control the leather production motor.

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