Industrial servo motor operation control method and system

Abstract

The present application relates to the field of motor operation control technology, and specifically to an industrial servo motor operation control method and system, the method comprising: real-time acquisition of load torque data and moment of inertia data of the servo motor; obtaining each oscillation time period and constant time period; analyzing the vibration amplitude, vibration frequency and change rate of the load torque data in each oscillation time period, and obtaining the load torque oscillation coefficient of each oscillation time period; obtaining the abnormal value of the moment of inertia in each oscillation time period; obtaining the synchronization coefficient of the load torque and moment of inertia change in each oscillation time period; obtaining the servo motor disturbance value in each oscillation time period; obtaining the optimized value of the gain coefficient of the sliding surface in the sliding mode controller at the current moment. The present application improves the response speed of the servo system to disturbances while avoiding the occurrence of jitter due to the servo system being too sensitive to disturbances, thereby improving the control accuracy of the servo motor speed.

Description

Technical Field

[0001] The present application relates to the technical field of motor operation control, and in particular to an industrial servo motor operation control method and system. Background Art

[0002] Industrial servo motors are motors that control the operation of mechanical components in a servo system. They are mainly used as actuators in servo systems and can convert voltage signals into torque and speed to drive the controlled object. Nonlinear and uncertain motion often exists in the industrial control process. In order to pursue higher accuracy and faster dynamic response, sliding mode controllers are often used to control the speed of servo motors.

[0003] However, industrial servo motors have strict requirements on speed smoothness. Traditional sliding mode variable structure control schemes have limitations in dealing with the coupled interference of sudden changes in load torque and moment of inertia vibration. They do not fully consider the synergistic effect of changes in load torque and moment of inertia, resulting in slow response of the servo system and insufficient sensitivity to disturbance changes, which affects the control accuracy of the servo motor speed. Summary of the invention

[0004] In view of the above, it is necessary to provide an industrial servo motor operation control method and system. Compared with the traditional industrial servo motor operation control method, while avoiding the servo system's overly sensitive response to disturbances and causing chattering, it improves the servo system's response speed to disturbances, thereby improving the control accuracy of the servo motor speed:

[0005] In a first aspect, an embodiment of the present application provides an industrial servo motor operation control method, the method comprising the following steps:

[0006] Collect the load torque data and moment of inertia data of the servo motor in real time;

[0007] Analyze the mutation of load torque data and obtain each oscillation time period and constant time period;

[0008] Analyze the vibration amplitude, vibration frequency and change rate of the load torque data in each oscillation time period to obtain the load torque oscillation coefficient in each oscillation time period;

[0009] Analyze the degree to which the moment of inertia data in each oscillation time period deviates from the moment of inertia data in all constant time periods, and obtain the abnormal value of the moment of inertia in each oscillation time period;

[0010] Analyze the difference between the load torque oscillation coefficient and the abnormal value of the moment of inertia, and obtain the synchronization coefficient of the load torque and the moment of inertia change in each oscillation time period;

[0011] For each oscillation time period and its multiple adjacent oscillation time periods, the discrete degree of the synchronization coefficient, the distribution of the load torque oscillation coefficient, and the distribution of the abnormal value of the moment of inertia are analyzed to obtain the servo motor disturbance value of each oscillation time period;

[0012] The optimized value of the gain coefficient of the sliding mode surface in the sliding mode controller at the current moment is obtained by combining the disturbance value of the servo motor in the adjacent oscillation time period at the current moment with the preset initial value of the gain coefficient of the sliding mode surface in the sliding mode controller in the servo motor.

[0013] In one embodiment, the process of obtaining the oscillating time period and the constant time period is as follows:

[0014] A mutation point detection algorithm is used to obtain each mutation point in all load torque data, and the appearance time of each mutation point is used as the starting time of each oscillation time period;

[0015] A window of preset size is constructed with each mutation point as the starting point, and the window is gradually slid to the right until the discreteness of the load torque data in the window is less than the preset threshold value, and the time corresponding to the load torque data at the leftmost end of each window is taken as the end time of each oscillation time period;

[0016] The time interval between any two adjacent oscillation time periods is regarded as each constant time period.

[0017] In one embodiment, the process of obtaining the load torque oscillation coefficient is as follows:

[0018] Arrange all load torque data in any oscillation time period in time sequence to obtain a fitting curve of all load torque data in any oscillation time period;

[0019] Calculating the sum of the differences between any two adjacent extreme values ​​on the fitting curve; the vibration amplitude is reflected by the sum;

[0020] Calculating the mean of the time intervals between any two adjacent extreme values ​​on the fitting curve; the vibration frequency is reflected by the mean;

[0021] The slope of the straight line formed by any two adjacent maximum value points and the slope of the straight line formed by any two adjacent minimum value points on the fitting curve are calculated respectively, and the absolute values ​​of all the slopes corresponding to the fitting curve are arranged in time series to form a slope sequence; the change rate is reflected by the data distribution in the slope sequence;

[0022] The data distribution in the slope sequence is analyzed, and the load torque oscillation coefficient of any oscillation time period is determined by combining the sum and the mean.

[0023] In one embodiment, the expression of the load torque oscillation coefficient is:

[0024] ; In the formula, represents the load torque oscillation coefficient of the i-th oscillation time period; represents the mean value in the i-th oscillation time period; represents the sum value in the i-th oscillation time period; They respectively represent the 1st and jth data in the slope sequence of the i-th oscillation time period; and N represents the number of data in the slope sequence of the i-th oscillation time period.

[0025] In one embodiment, the process of obtaining the abnormal value of the moment of inertia is:

[0026] Arrange all the moment of inertia data in each oscillation time period in time sequence to form each moment of inertia sequence, and obtain the fitting curve of all the moment of inertia data in each moment of inertia sequence, which is recorded as each moment of inertia curve;

[0027] Calculate the average value of the moment of inertia data in all constant time periods before the current moment;

[0028] A rectangular coordinate system is constructed with the order of the moment of inertia data in the moment of inertia sequence as the abscissa and the moment of inertia data as the ordinate, and a straight line in the rectangular coordinate system whose ordinate value is equal to the average value is used as a constant state straight line;

[0029] The abnormal value of the moment of inertia is the area of ​​a graph enclosed by the moment of inertia curve and the steady state straight line.

[0030] In one embodiment, the synchronization coefficient is obtained by recording the difference between the normalized value of the load torque oscillation coefficient in each oscillation time period and the normalized value of the moment of inertia abnormal value as the abnormal difference, and the synchronization coefficient is negatively correlated with the abnormal difference.

[0031] In one embodiment, the process of obtaining the servo motor disturbance value is as follows:

[0032] The mean of the normalized values ​​of the load torque oscillation coefficient in each oscillation time period and its multiple adjacent oscillation time periods and the mean of the normalized values ​​of the moment of inertia abnormal values ​​are recorded as the first mean and the second mean, respectively;

[0033] The servo motor disturbance value is determined by the discrete degree of the synchronization coefficient in each oscillation time period and a plurality of adjacent oscillation time periods, the first mean value, and the second mean value.

[0034] In one embodiment, the expression of the servo motor disturbance value is:

[0035] ; In the formula, represents the disturbance value of the servo motor in the i-th oscillation time period; Indicates the discrete degree of the synchronization coefficient in the i-th oscillation time period and its multiple adjacent oscillation time periods; represents the average value of the first mean value and the second mean value in the i-th oscillation time period; γ represents a preset value greater than 0.

[0036] In one embodiment, the process of obtaining the optimized value of the gain coefficient of the sliding mode surface in the sliding mode controller at the current moment is:

[0037] The normalized value of the servo motor disturbance value in the previous oscillation time period adjacent to the current moment is recorded as the disturbance normalized value;

[0038] The optimized value is positively correlated with the preset initial value and the disturbance normalized value respectively.

[0039] In a second aspect, an embodiment of the present application also provides an industrial servo motor operation control system, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of any one of the above-mentioned industrial servo motor operation control methods when executing the computer program.

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

[0041] The present application obtains the load torque oscillation coefficient of each oscillation time period by analyzing the vibration amplitude, vibration frequency and change rate of the load torque data in each oscillation time period, and analyzes the oscillation degree of the load torque from multiple angles, which can improve the reliability of the analysis of the oscillation degree of the load torque; analyzes the speed of recovery from a sudden change in the moment of inertia to the state before the sudden change, and then obtains the synchronization coefficient in combination with the degree of synchronization between the load torque and the moment of inertia; obtains the servo motor disturbance value by the stability of the synchronization coefficient in multiple consecutive oscillation time periods, and the degree of influence of the load torque and the moment of inertia on the disturbance, and reflects the degree of disturbance to the servo motor. Compared with the conventional method of only analyzing the vibration of the load torque data, it can more accurately reflect the strength of the disturbance to the servo motor;

[0042] Furthermore, according to the real-time disturbance state during the operation of the servo motor, the gain coefficient of the sliding surface in the sliding film controller in the servo motor is adjusted in time, so as to avoid the servo system from being too sensitive to the disturbance and causing jitter, improve the response speed of the servo system to the disturbance, enhance the anti-disturbance ability of the servo system, and thus improve the control accuracy of the servo motor speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] 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.

[0044] Figure 1 A flowchart of a method for controlling the operation of an industrial servo motor provided by one embodiment of the present application;

[0045] Figure 2 It is a schematic diagram of the process of obtaining the load torque oscillation coefficient;

[0046] Figure 3 Schematic diagram of the process of obtaining the disturbance value of the servo motor. DETAILED DESCRIPTION

[0047] In the description of the embodiments of the present application, words such as "exemplary", "or", "for example" and the like are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "or", "for example" and the like is intended to present related concepts in a concrete manner.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the present application. The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. It should be understood that, unless otherwise specified, " / " means or.

[0049] It should also be noted that the terms "first" and "second" in the present application are used to distinguish similar objects rather than to describe a specific order or sequence.

[0050] The specific scheme of an industrial servo motor operation control method and system provided by the present application is described in detail below with reference to the accompanying drawings.

[0051] See also Figure 1 , which shows a flowchart of a method for controlling the operation of an industrial servo motor provided by an embodiment of the present application, the method comprising the following steps:

[0052] Step 1: collect the load torque data and rotational inertia data of the servo motor in real time.

[0053] During the operation of the servo motor, the speed needs to be kept constant and smooth to improve the accuracy of control. However, the speed constancy and smoothness will be affected by many factors, the main factors being the changes in load torque and moment of inertia. In order to analyze the changes in load torque and moment of inertia and the specific impact characteristics on the speed of the servo motor, this embodiment collects the load torque data of the servo motor in real time through a torque sensor, and uses a model reference adaptive algorithm to identify the moment of inertia of the servo motor. The model reference adaptive algorithm can identify the size of the moment of inertia based on the load torque data of the servo motor through a model, and output the moment of inertia data of the servo motor at each acquisition moment. Among them, the model reference adaptive algorithm is a well-known technology and will not be repeated in this application.

[0054] Among them, the collection frequency of load torque data and moment of inertia data is 1KHZ. The value of the collection frequency is preset manually and can be set by the implementer. This application does not impose any special restrictions.

[0055] Step 2, deeply analyze the oscillation characteristics of the load torque of the servo motor and the speed of smooth recovery of the moment of inertia, further obtain the synchronization characteristics of the load torque and the moment of inertia change, and obtain the servo motor disturbance value through the stable state of the synchronization characteristics and the degree of influence of the load torque and the moment of inertia on the disturbance.

[0056] Industrial servo motors usually require high position tracking accuracy and strong anti-interference ability. However, the load of the servo motor will change due to different tasks, causing certain disturbances to the servo system, which in turn causes a decrease in the control accuracy of the servo motor. Sliding mode variable structure control technology plays a key role in the above situation. Its core advantage lies in the fast and accurate tracking of the speed of the servo motor to ensure the constancy and smoothness of the speed. In the sliding mode controller, the gain coefficient of the sliding surface is the core parameter, which has a profound impact on the control accuracy of the speed. Specifically, if the gain coefficient is too large, the system will be overly sensitive to disturbances, resulting in frequent jitter, damaging system stability and reducing the service life of the equipment; on the contrary, if the gain coefficient is too small, it takes a long time for the system state to approach the sliding surface, and the response rate is slow when facing disturbances, which cannot meet the real-time control requirements.

[0057] Therefore, in order to achieve the goal of high-precision speed control, it is necessary to adjust the gain coefficient of the sliding surface according to the real-time disturbance state of the servo motor. The synchronous characteristics of the load torque and the moment of inertia change are the key characteristics of the motor disturbance state. By deeply exploring the intrinsic relationship between this synchronous characteristic and the disturbance, the gain coefficient of the sliding surface can be adaptively adjusted, thereby comprehensively improving the speed control accuracy, dynamic response performance and overall reliability of the servo motor under complex working conditions.

[0058] Step 2.1, analyze the mutation of load torque data and obtain each oscillation time period and constant time period.

[0059] Based on the above analysis, the specific change characteristics of the load torque data and the moment of inertia data are analyzed. Taking the load torque data as an example, the torque is a kind of torque that makes the object rotate. The torque of the industrial servo motor will change with the change of the torque required by the task. The change of the motor torque follows the law of gradual change, rather than a simple step-like mutation. The transition from the initial torque value to the target torque value will undergo a continuous and complex dynamic change process. Specifically, when the torque adjustment program is started, regardless of the increase or decrease trend, the oscillation phenomenon of the load torque data will be triggered, and the oscillation amplitude is initially large. As the servo system's own adjustment mechanism intervenes, it gradually decays according to the damping characteristics until it reaches a steady-state equilibrium. This process is affected by the interaction of multiple factors such as the electromagnetic characteristics of the motor, the flexibility of the mechanical transmission system, and the moment of inertia, presenting complex nonlinear dynamic characteristics.

[0060] Based on the above analysis, the time period when the load torque data oscillates is extracted. During the operation of the servo motor, the time period when the load torque oscillates is extremely short. In multiple consecutive oscillation time periods, if the changes in the load torque and the moment of inertia show synergistic characteristics, it can reflect the disturbance state of the servo motor to a certain extent.

[0061] In this embodiment, the motor speed is adjusted in each adjustment interval, and the adjustment interval is set from the end time of the previous oscillation time period to the end time of the next oscillation time period. One adjustment interval contains only one oscillation time period, and adjacent oscillation time periods are discontinuous in time. In order to obtain the time period when the load torque data oscillates, all the collected load torque data are arranged in time sequence, and the mutation point detection algorithm is used to obtain the mutation points in all the load torque data. The appearance time of each mutation point is the starting time of each oscillation time period, and each window of a preset size is constructed with each mutation point as the starting point. Slide to the right according to the preset step size until the discrete degree of the load torque data in the window is less than the preset threshold value, and the time corresponding to the load torque data at the leftmost end of each window is used as the end time of each oscillation time period. The time interval between any two adjacent oscillation time periods is used as each constant time period. For the first oscillation time period, the time interval before the oscillation time period is used as the constant time period. Each constant time period and the next adjacent oscillation time period form each adjustment interval.

[0062] In this embodiment, the Bernaola Galvan segmentation algorithm is used to obtain the mutation points in the load torque data. As other implementation methods, based on the ability to obtain the mutation points in the load torque data, the implementer may use other existing technologies to obtain the mutation points, such as the Bayesian mutation point detection algorithm, the Mann-Kendall mutation point detection algorithm, etc. This application does not impose any special restrictions.

[0063] In this embodiment, the size of the window is , the preset step size is 1, the preset threshold value is 0.1, the window size, the preset step size and the preset threshold value are preset manually, and the implementer can set them by himself. This application does not impose any special restrictions.

[0064] In this embodiment, the degree of discreteness of the load torque data is the standard deviation. As other implementation methods, on the basis of being able to measure the uneven distribution of the load torque data, the implementer may use other existing technologies for measurement, such as variance, coefficient of variation, etc., and this application does not impose any special restrictions.

[0065] Step 2.2, analyzing the vibration amplitude, vibration frequency and change rate of the load torque data in each oscillation time period, and obtaining the load torque oscillation coefficient of each oscillation time period.

[0066] The load torque data shows a characteristic of gradually decreasing in a wave-like manner during the oscillation process. If the rate of data oscillation decreases in the oscillation time period is slower, and the oscillation interval between adjacent waves is larger, and the difference in fluctuation is smaller, it indicates that the process of load torque reaching stability is slower, and the possibility of being affected by motor interference is greater. Taking the i-th oscillation time period as an example, based on the above characteristics, all load torque data in the i-th oscillation time period are arranged in time sequence to form a load torque sequence of the i-th oscillation time period. Obtain a fitting curve of all load torque data in the load torque sequence, record the difference between any two adjacent extreme values ​​on the fitting curve as the extreme value difference, and calculate the sum of all the extreme value differences corresponding to the fitting curve; calculate the time interval at the moment when any two adjacent extreme values ​​on the fitting curve are located, calculate the mean of all the time intervals corresponding to the fitting curve, calculate the slope of the straight line formed by any two adjacent maximum value points on the fitting curve, and the slope of the straight line formed by any two adjacent minimum value points, and arrange the absolute values ​​of all the slopes corresponding to the fitting curve in time sequence to form a slope sequence. Among them, the calculation of the slope is a well-known technology, and this application will not repeat it.

[0067] In this embodiment, the least squares method is used to obtain the fitting curve of the load torque data. As other implementation methods, based on the fitting curve of the load torque data, the implementer can adopt other existing technologies, such as local weighted regression, K-nearest neighbor regression, etc., and this application does not impose any special restrictions.

[0068] In this embodiment, the difference between adjacent extreme values ​​and the difference between the moments at which adjacent extreme values ​​are located are both absolute values ​​of the difference. On the basis of being able to measure the difference between adjacent extreme values ​​and the difference between the moments at which adjacent extreme values ​​are located, the implementer may adopt other calculation methods, such as the square of the difference, etc., and this application does not impose any special restrictions.

[0069] The data distribution in the slope sequence is analyzed, and the load torque oscillation coefficient of the i-th oscillation time period is determined by combining the sum and the mean. The expression is:

[0070] ; In the formula, represents the load torque oscillation coefficient of the i-th oscillation time period; represents the mean value in the i-th oscillation time period; represents the sum value in the i-th oscillation time period; They respectively represent the 1st and jth data in the slope sequence of the i-th oscillation time period; and N represents the number of data in the slope sequence of the i-th oscillation time period.

[0071] It should be noted that: If The larger it is, the greater the time difference between waves during the oscillation process; The smaller the value, the smaller the amplitude difference between the waves in the oscillation process; since the absolute value of the first slope in the oscillation process is the largest and then gradually decreases, the obtained The larger the load torque, the slower the oscillation rate. The larger the load torque oscillation coefficient, the larger the load torque oscillation coefficient. Figure 2 shown.

[0072] The load torque oscillation coefficients of the remaining oscillation time periods are obtained using the same calculation method as the load torque oscillation coefficient of the i-th oscillation time period.

[0073] Step 2.3, analyzing the degree to which the moment of inertia data in each oscillation time period deviates from the moment of inertia data in all constant time periods, and obtaining the abnormal value of the moment of inertia in each oscillation time period.

[0074] The sudden change of load torque is caused by the change of the torque required by the task. This change is usually accompanied by the change of the moment of inertia, so that the change time of the moment of inertia is consistent with the change time of the load torque. The moment of inertia data is constant most of the time. When a change occurs, its waveform shows that the data after the sudden change smoothly recovers to the data before the sudden change. The speed of smooth recovery reflects the degree of influence of the moment of inertia on the disturbance. The faster the smooth recovery, the smaller the area enclosed by the fluctuation curve formed when the moment of inertia changes and the constant state straight line. Conversely, the larger the area enclosed by the fluctuation curve formed when the moment of inertia changes and the constant state straight line, the greater the degree of influence of the disturbance.

[0075] Based on the above analysis, still taking the i-th oscillation time period as an example, all the moment of inertia data in the i-th oscillation time period are arranged in time sequence to form a moment of inertia sequence, and the least square method is used to obtain the fitting curve of all the moment of inertia data in the moment of inertia sequence, which is recorded as the moment of inertia curve, and the average value of the moment of inertia data in all constant time periods before the current moment is calculated. The order of the moment of inertia data in the moment of inertia sequence is used as the horizontal coordinate, and the moment of inertia data is used as the vertical coordinate to construct a rectangular coordinate system, and the straight line with the vertical coordinate value equal to the average value in the rectangular coordinate system is used as the constant state straight line, and the area of ​​the figure enclosed by the moment of inertia curve and the constant state straight line is used as the moment of inertia abnormal value of the i-th oscillation time period. The larger the moment of inertia abnormal value, the slower the speed of the moment of inertia data recovery. Among them, the use of definite integral to calculate the area of ​​the figure enclosed by the moment of inertia curve and the constant state straight line, and the process of using definite integral to calculate the area of ​​the figure is a well-known technology, and this application will not repeat it.

[0076] The abnormal values ​​of the moment of inertia of the remaining oscillation time periods are obtained by the same calculation method as the abnormal value of the moment of inertia of the i-th oscillation time period.

[0077] Step 2.4, analyzing the difference between the load torque oscillation coefficient and the abnormal value of the moment of inertia, and obtaining the synchronization coefficient of the load torque and the moment of inertia change in each oscillation time period.

[0078] The synchronous characteristics of the load torque and the moment of inertia change can reflect the degree of disturbance to the servo motor to a certain extent. When the servo motor encounters system vibration or overshoot, the slower the moment of inertia returns to a constant state and the greater the oscillation of the load torque, the more obvious the disturbance to the servo motor.

[0079] Based on the above analysis, the difference between the load torque oscillation coefficient and the abnormal value of the moment of inertia is analyzed to obtain the synchronization coefficient of the load torque and the moment of inertia change in each oscillation time period, and the expression is:

[0080] ; In the formula, It represents the synchronization coefficient between the load torque and the moment of inertia change in the i-th oscillation time period; represents the normalized value of the load torque oscillation coefficient in the i-th oscillation time period; represents the normalized value of the abnormal moment of inertia of the i-th oscillation time period; β represents a value greater than 0, in order to avoid the denominator being 0. The value of β is preset by humans and can be set by the implementer. In this embodiment, the value of β is 0.1. Recorded as abnormal differences.

[0081] In this embodiment, the Min-Max normalization method is used to normalize the load torque oscillation coefficient and the moment of inertia abnormal value. As other implementation methods, on the basis of being able to realize the normalization of the load torque oscillation coefficient and the moment of inertia abnormal value, the implementer can adopt other existing technologies, such as the Z-Score normalization method, the decimal calibration normalization method, etc., and this application does not make any special restrictions.

[0082] It should be noted that: The smaller the value, the closer the change degree of the load torque and the moment of inertia in the i-th oscillation time period is, and the stronger the synchronization of the load torque and the moment of inertia change is. The bigger.

[0083] The synchronization coefficients of the load torque and the moment of inertia change in the remaining oscillation time periods are obtained using the same calculation method as the synchronization coefficient in the i-th oscillation time period.

[0084] Step 2.5, for each oscillation time period and its multiple adjacent oscillation time periods, analyze the discreteness of the synchronization coefficient, the distribution of the load torque oscillation coefficient, and the distribution of the abnormal value of the moment of inertia, and obtain the servo motor disturbance value of each oscillation time period.

[0085] Furthermore, if the synchronization degree of the load torque and the moment of inertia in a plurality of consecutive oscillation time periods is similar, and the load torque and the moment of inertia are more obviously affected by the disturbance, it indicates that the disturbance existing in the servo motor is stronger.

[0086] Based on the above analysis, for each oscillation time period and its multiple adjacent oscillation time periods, the discrete degree of the synchronization coefficient, the distribution of the load torque oscillation coefficient, and the distribution of the abnormal value of the moment of inertia are analyzed to obtain the servo motor disturbance value of each oscillation time period. The expression is:

[0087] ; In the formula, represents the disturbance value of the servo motor in the i-th oscillation time period; Indicates the degree of dispersion of the synchronization coefficient in the i-th oscillation time period and its multiple neighboring oscillation time periods; the mean of the normalized value of the load torque oscillation coefficient in each oscillation time period and its multiple neighboring oscillation time periods and the mean of the normalized value of the moment of inertia anomaly are recorded as the first mean and the second mean, respectively; represents the average value of the first mean and the second mean in the i-th oscillation time period; γ represents a preset value greater than 0, the purpose of which is to avoid the denominator being 0. The value of γ is preset manually and can be set by the implementer. In this embodiment, the value of γ is 0.1.

[0088] In this embodiment, the 9 oscillation time periods before and adjacent to the i-th oscillation time period are used as the neighboring oscillation time periods of the i-th oscillation time period. If the number of neighboring oscillation time periods of the i-th oscillation time period is less than 9, the servo motor disturbance value of the i-th oscillation time period is not calculated, wherein 9 is only one embodiment of the present application, and the value of the number of neighboring oscillation time periods is preset artificially and can be set by the implementer, and the present application does not impose any special restrictions.

[0089] It should be noted that: The smaller it is, the more stable the change of the synchronization coefficient in the i-th oscillation time period and its multiple oscillation time periods is; The larger it is, the greater the influence of the disturbance on the load torque and moment of inertia in the i-th oscillation time period is; The larger the value is, the stronger the disturbance in the servo motor is. The schematic diagram of the process of obtaining the disturbance value of the servo motor is as follows: Figure 3 shown.

[0090] The servo motor disturbance values ​​of the remaining oscillation time periods are obtained using the same calculation method as the servo motor disturbance value of the i-th oscillation time period.

[0091] Step 3, obtaining the optimized value of the gain coefficient of the sliding mode surface in the sliding mode controller at the current moment through the servo motor disturbance value of the adjacent oscillation time period at the current moment and the preset initial value of the gain coefficient of the sliding mode surface in the sliding mode controller in the servo motor.

[0092] In actual operation, if the gain coefficient of the sliding surface is too large, the system will be overly sensitive to disturbances and produce chattering. To reduce the chattering phenomenon, the gain coefficient of the sliding surface needs to be reduced; if the gain coefficient of the sliding surface is too small, the system's response rate to disturbances is slow. To increase the response speed, the gain coefficient of the sliding surface needs to be increased. Therefore, the gain coefficient of the sliding surface should not be too large or too small. The range of the gain coefficient of the sliding surface needs to be determined based on the above reasons. In this embodiment, the range of the gain coefficient of the sliding surface is [-10, -0.7].

[0093] Since the servo motor disturbance value reflects the disturbance degree during the operation of the servo motor, in order to achieve more accurate speed control, the gain coefficient of the sliding mode surface in the sliding mode controller is adjusted based on the servo motor disturbance value.

[0094] If the disturbance degree of the servo motor is greater, a larger gain coefficient needs to be set to increase the response speed to the disturbance; if the disturbance degree of the servo motor is smaller, a smaller gain coefficient needs to be set to avoid the system's overly sensitive response to the disturbance and causing jitter. The specific optimization formula for the gain coefficient is: ; In the formula, Represents the optimized value of the gain coefficient of the sliding surface in the sliding mode controller at the current moment; Z represents the preset initial value of the gain coefficient of the sliding surface in the sliding mode controller in the servo motor; R represents the normalized value of the servo motor disturbance value in the previous oscillation time period adjacent to the current moment. The purpose of normalizing the servo motor disturbance value is to scale the servo motor disturbance value so that the optimized value of the gain coefficient of the sliding surface is within the value range; ε represents a preset value greater than 0, which is used to determine the adjustment amplitude of the gain coefficient. The larger ε is, the more sensitive the gain coefficient is to R. In the same adjustment interval, the optimized value at all acquisition moments is the same. R is recorded as the disturbance normalization value.

[0095] In this embodiment, in order to ensure that the optimized value of the gain coefficient of the sliding surface is within the value range, the value of Z is -7. The value of Z is preset manually, and the implementer can set it according to the actual situation. This application does not impose any special restrictions.

[0096] In this embodiment, the Min-Max normalization method is used to normalize the servo motor disturbance value. As other implementation methods, on the basis of being able to realize the normalization of the servo motor disturbance value, the implementer may use other existing technologies to normalize the servo motor disturbance value, such as decimal calibration normalization method, Sigmoid function, etc., and this application does not make any special restrictions.

[0097] In this embodiment, in order to avoid excessive adjustment of the gain coefficient, the value of ε is 5. The value of ε is preset manually and can be set by the implementer. This application does not impose any special restrictions.

[0098] Based on the same inventive concept as the above method, an embodiment of the present application also provides an industrial servo motor operation control system, 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 industrial servo motor operation control methods are implemented.

[0099] In summary, the present application obtains the load torque oscillation coefficient of each oscillation time period by analyzing the vibration amplitude, vibration frequency and change rate of the load torque data in each oscillation time period, and analyzes the oscillation degree of the load torque from multiple angles, which can improve the reliability of the analysis of the oscillation degree of the load torque; analyzes the speed of recovery from the sudden change of the moment of inertia to the state before the sudden change, and then obtains the synchronization coefficient in combination with the degree of synchronization between the load torque and the moment of inertia; obtains the servo motor disturbance value by the stability of the synchronization coefficient in multiple consecutive oscillation time periods, and the degree of influence of the load torque and the moment of inertia on the disturbance, and reflects the degree of disturbance to the servo motor. Compared with the conventional method of only analyzing the vibration of the load torque data, it can more accurately reflect the strength of the disturbance to the servo motor;

[0100] Furthermore, according to the real-time disturbance state during the operation of the servo motor, the gain coefficient of the sliding surface in the sliding film controller in the servo motor is adjusted in time, so as to avoid the servo system from being too sensitive to the disturbance and causing jitter, improve the response speed of the servo system to the disturbance, enhance the anti-disturbance ability of the servo system, and thus improve the control accuracy of the servo motor speed.

[0101] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

[0102] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the basic features of the present application. Therefore, no matter from which point of view, the above embodiments of the present application should be regarded as exemplary and non-restrictive.

Claims

1. An industrial servo motor operation control method, characterized in that: The method comprises the following steps: Collect the load torque data and moment of inertia data of the servo motor in real time; Analyze the mutation of load torque data and obtain each oscillation time period and constant time period; Analyze the vibration amplitude, vibration frequency and change rate of the load torque data in each oscillation time period to obtain the load torque oscillation coefficient in each oscillation time period; Analyze the degree to which the moment of inertia data in each oscillation time period deviates from the moment of inertia data in all constant time periods, and obtain the abnormal value of the moment of inertia in each oscillation time period; Analyze the difference between the load torque oscillation coefficient and the abnormal value of the moment of inertia, and obtain the synchronization coefficient of the load torque and the moment of inertia change in each oscillation time period; For each oscillation time period and its multiple adjacent oscillation time periods, the discrete degree of the synchronization coefficient, the distribution of the load torque oscillation coefficient, and the distribution of the abnormal value of the moment of inertia are analyzed to obtain the servo motor disturbance value of each oscillation time period; The optimized value of the gain coefficient of the sliding mode surface in the sliding mode controller at the current moment is obtained by combining the disturbance value of the servo motor in the adjacent oscillation time period at the current moment with the preset initial value of the gain coefficient of the sliding mode surface in the sliding mode controller in the servo motor; The acquisition process of the servo motor disturbance value is as follows: the mean of the normalized value of the load torque oscillation coefficient of the i-th oscillation time period and its multiple adjacent oscillation time periods and the mean of the normalized value of the moment of inertia abnormal value are recorded as the first mean and the second mean, respectively, and the average of the first mean and the second mean is recorded as , the servo motor disturbance value of the i-th oscillation time period is recorded as , The expression is: , where represents the discrete degree of the synchronization coefficient in the i-th oscillation time period and its multiple adjacent oscillation time periods, and γ represents a preset value greater than 0.

2. An industrial servo motor operation control method as claimed in claim 1, characterized in that: The acquisition process of the oscillating time period and the constant time period is as follows: A mutation point detection algorithm is used to obtain each mutation point in all load torque data, and the appearance time of each mutation point is used as the starting time of each oscillation time period; A window of preset size is constructed with each mutation point as the starting point, and the window is gradually slid to the right until the discreteness of the load torque data in the window is less than the preset threshold value, and the time corresponding to the load torque data at the leftmost end of each window is taken as the end time of each oscillation time period; The time interval between any two adjacent oscillation time periods is regarded as each constant time period.

3. The industrial servo motor operation control method according to claim 1, characterized in that: The process of obtaining the load torque oscillation coefficient is as follows: Arrange all load torque data in any oscillation time period in time sequence to obtain a fitting curve of all load torque data in any oscillation time period; Calculating the sum of the differences between any two adjacent extreme values ​​on the fitting curve; the vibration amplitude is reflected by the sum; Calculating the mean of the time intervals between any two adjacent extreme values ​​on the fitting curve; the vibration frequency is reflected by the mean; The slope of the straight line formed by any two adjacent maximum value points and the slope of the straight line formed by any two adjacent minimum value points on the fitting curve are calculated respectively, and the absolute values ​​of all the slopes corresponding to the fitting curve are arranged in time series to form a slope sequence; the change rate is reflected by the data distribution in the slope sequence; The data distribution in the slope sequence is analyzed, and the load torque oscillation coefficient of any oscillation time period is determined by combining the sum and the mean.

4. An industrial servo motor operation control method as claimed in claim 3, characterized in that: The expression of the load torque oscillation coefficient is: ; In the formula, represents the load torque oscillation coefficient of the i-th oscillation time period; represents the mean value in the i-th oscillation time period; represents the sum value in the i-th oscillation time period; They respectively represent the 1st and jth data in the slope sequence of the i-th oscillation time period; and N represents the number of data in the slope sequence of the i-th oscillation time period.

5. The industrial servo motor operation control method according to claim 1, characterized in that: The process of obtaining the abnormal value of the moment of inertia is as follows: Arrange all the moment of inertia data in each oscillation time period in time sequence to form each moment of inertia sequence, and obtain the fitting curve of all the moment of inertia data in each moment of inertia sequence, which is recorded as each moment of inertia curve; Calculate the average value of the moment of inertia data in all constant time periods before the current moment; A rectangular coordinate system is constructed with the order of the moment of inertia data in the moment of inertia sequence as the abscissa and the moment of inertia data as the ordinate, and a straight line whose ordinate value in the rectangular coordinate system is equal to the average value is used as a constant state straight line; The abnormal value of the moment of inertia is the area of ​​a graph enclosed by the moment of inertia curve and the steady state straight line.

6. The industrial servo motor operation control method according to claim 1, characterized in that: The process of acquiring the synchronization coefficient is as follows: the difference between the normalized value of the load torque oscillation coefficient in each oscillation time period and the normalized value of the moment of inertia abnormal value is recorded as the abnormal difference, and the synchronization coefficient is negatively correlated with the abnormal difference.

7. The industrial servo motor operation control method according to claim 1, characterized in that: The process of obtaining the optimized value of the gain coefficient of the sliding mode surface in the sliding mode controller at the current moment is: The normalized value of the servo motor disturbance value in the previous oscillation time period adjacent to the current moment is recorded as the disturbance normalized value; The optimized value is positively correlated with the preset initial value and the disturbance normalized value respectively.

8. An industrial servo motor operation control system, 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 the industrial servo motor operation control method as described in any one of claims 1-7 are implemented.

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