Eccentric shaft grinding control method capable of avoiding workpiece collision

Abstract

The invention relates to the technical field of feeding amount control, in particular to an eccentric shaft grinding control method capable of avoiding workpiece collision, which comprises the following steps: in the process of grinding an eccentric shaft by a processing machine tool, acquiring the actual rotating speed of a grinding wheel at each moment in a preset local time period before the current moment and the actual feeding amount of the grinding wheel at the current moment in real time; calculating the rotating speed variation; determining the friction balance degree of the grinding wheel at the current moment; and the abrasion coefficient of the grinding wheel at the current moment is obtained, the adjusted feeding amount of the grinding wheel at the current moment is determined, and the feeding amount of the grinding wheel is controlled and adjusted through a control algorithm. The feeding amount of the grinding wheel is adjusted in real time, the feeding amount of the grinding wheel is controlled more accurately, collision and impact in the grinding process are effectively avoided, the risk of damage to workpieces and equipment is reduced, and the machining precision of the eccentric shaft is improved.

Description

Technical Field

[0001] This application relates to the technical field of feed rate control, and particularly to an eccentric shaft grinding control method for avoiding workpiece collision. Background Art

[0002] The eccentric shaft is one of the core components of the RV reducer. Through its eccentric design, it drives components such as the cycloid gear to perform eccentric motion, thereby realizing the deceleration function. During the grinding process of the eccentric shaft, the horizontal feed (X direction) of the grinding wheel frame and the rotation (C direction) of the workpiece need to be linked, and the grinding wheel needs to track the rotation of the eccentric shaft. However, due to factors such as commutation inertia, the grinding wheel is prone to reciprocating impact vibration at the end point of the X-direction stroke, resulting in collision between the grinding wheel and the workpiece, affecting the surface quality of the workpiece, and even damaging the workpiece and the grinding equipment.

[0003] Traditional technologies generally calculate the trajectory of the eccentric shaft through the method of tangent point tracking, and then control the feed rate of the grinding wheel in the X-C two-axis linkage grinding machine. However, during the grinding of the eccentric shaft, the grinding will cause the radius of the grinding wheel to gradually decrease, resulting in an error in the eccentricity calculated by the trajectory formula of the eccentric shaft, leading to a deviation in the control of the feed rate of the grinding wheel and affecting the machining accuracy of the eccentric shaft. Summary of the Invention

[0004] In order to solve the above technical problems, an eccentric shaft grinding control method for avoiding workpiece collision is provided to solve the existing problems.

[0005] The solution of this application to solve the technical problem is to provide an eccentric shaft grinding control method for avoiding workpiece collision, including the following steps: During the grinding process of the eccentric shaft by the processing machine tool, the actual rotational speed of the grinding wheel at each moment within a preset local time period before the current moment is obtained in real time, as well as the actual feed rate of the grinding wheel at the current moment; using the rotational speed situation of the eccentric shaft, all moments within the preset local time period are divided into multiple grinding cycles; each moment within each grinding cycle is numbered respectively, and the moments corresponding to the same serial number within all grinding cycles are recorded as the cycle moments; Analyze the difference situation and its change trend of the actual rotational speeds corresponding to different grinding cycles at each cycle moment, and calculate the rotational speed change amount at each cycle moment; determine the friction balance degree of the grinding wheel at the current moment through the change characteristics of the extreme points of the rotational speed change amounts at all cycle moments and the number of extreme points; Based on the deviation degree of the actual rotational speeds at different moments within the preset local time period at the current moment, combined with the friction balance degree, obtain the wear coefficient of the grinding wheel at the current moment; Based on the wear coefficient, determine the adjusted feed rate of the grinding wheel at the current moment, and combined with the actual feed rate, control and adjust the feed rate of the grinding wheel through a control algorithm.

[0006] Preferably, according to the rotational speed condition of the eccentric shaft, all moments within a preset local time period are divided into multiple grinding cycles, including: taking the time required for the eccentric shaft to rotate one week as one grinding cycle, and dividing all moments within the preset local time period into multiple grinding cycles.

[0007] Preferably, the calculation of the rotational speed change amount at each cycle moment includes: Selecting the actual rotational speeds corresponding to all grinding cycles at each cycle moment to form a cycle sequence at each cycle moment; Calculating the average value of the differences between all any two elements within the cycle sequence, which is denoted as the relative difference amount; Analyzing the difference situation between adjacent elements within the cycle sequence, and determining the quantity difference between the number of positive and negative differences among all adjacent elements; The rotational speed change amount is the ratio of the quantity difference to the relative difference amount.

[0008] Preferably, the further determination process of the quantity difference is: Calculating the first-order difference sequence for the cycle sequence, and statistically counting the number of elements that are positive and negative respectively within the first-order difference sequence; Denoting the difference between the number of positive values and the number of negative values as the quantity difference.

[0009] Preferably, determining the friction balance degree of the grinding wheel at the current moment includes: Obtaining the extreme points of the rotational speed change amounts at all cycle moments; calculating the maximum value of the rotational speed change amounts corresponding to all extreme points; Statistically counting the number of all extreme points; denoting the difference between the number and a preset ideal number as the quantity deviation; Negatively fusing the maximum value with the quantity deviation to obtain the friction balance degree of the grinding wheel at the current moment.

[0010] Preferably, the further determination method for the negative fusion is: calculating the ratio of the maximum value to the quantity deviation as the friction balance degree of the grinding wheel at the current moment.

[0011] Preferably, the further measurement process of the deviation degree is: calculating the average value of the differences between the actual rotational speeds of all moments within the preset local time period at the current moment and the preset theoretical rotational speed, which is denoted as the rotational speed deviation.

[0012] Preferably, the wear coefficient is the normalized result of the ratio of the friction balance degree to the rotational speed deviation.

[0013] Preferably, the feed rate after adjustment of the grinding wheel at the current moment ​ The calculation formula is as follows: , where is the wear coefficient of the grinding wheel at the current moment , and is the preset initial feed rate.

[0014] Preferably, the control and adjustment of the feed rate of the grinding wheel include: recording the difference between the actual feed rate of the grinding wheel at the current moment and the adjusted feed rate as the target deviation; using the target deviation as the input of the PID control algorithm to control and adjust the feed rate of the grinding wheel.

[0015] This application has at least the following beneficial effects: By analyzing the differences in the actual rotational speeds corresponding to different grinding cycles at each cycle moment, this application calculates the change in rotational speed. The beneficial effect is that it considers the periodic fluctuations in the rotational speed of the grinding wheel to illustrate the grinding effect of the grinding wheel on the eccentric shaft, and thereby indirectly reflects the wear condition of the grinding wheel; determining the friction balance degree of the grinding wheel at the current moment, the beneficial effect is that it considers the change in the change in rotational speed, reflects the situation of collision between the grinding wheel and the eccentric shaft and the grinding effect of the grinding wheel on the eccentric shaft, explains the adjustment of the feed rate of the grinding wheel, so as to avoid subsequent collisions and severe vibrations between the grinding wheel and the workpiece, which affect the machining quality of the surface of the eccentric shaft, and can further reflect the wear condition of the grinding wheel; secondly, obtaining the wear coefficient of the grinding wheel at the current moment, the beneficial effect is that it considers the deviation of the actual rotational speed of the grinding wheel during the grinding process, reflects the change in the frictional force between the grinding wheel and the eccentric shaft during the grinding process, and explains the significant wear condition of the grinding wheel, so as to determine whether it is necessary to increase the feed rate of the grinding wheel subsequently to ensure that the grinding wheel has sufficient grinding force on the eccentric shaft; determining the adjusted feed rate of the grinding wheel at the current moment, and combining the actual feed rate, controlling and adjusting the feed rate of the grinding wheel through a control algorithm. The beneficial effect is that compared with traditional methods, it adjusts the feed rate in real time according to the wear degree of the grinding wheel, solves the problem of insufficient or excessive feed rate caused by the wear of the grinding wheel, more precisely controls the feed rate of the grinding wheel, effectively avoids collisions and impacts during the grinding process, reduces the risk of damage to the workpiece and equipment, improves the machining accuracy of the eccentric shaft, reduces the dimensional error of the eccentric shaft, can better meet the requirements of high-precision industrial production, and provides higher quality assurance for subsequent assembly and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following further elaborates in detail a method for controlling the grinding of an eccentric shaft to avoid workpiece collision in this application with reference to the drawings.

[0017] Figure 1 is the flowchart of the steps of a method for controlling the grinding of an eccentric shaft to avoid workpiece collision provided by an embodiment of this application; Figure 2 The flowchart of the method for obtaining the friction balance degree of the grinding wheel at the current moment provided by the embodiment of the present application. Detailed implementation manners

[0018] In order to make the purpose, technical solutions and advantages of the present application clearer, the following further elaborates in detail on an eccentric shaft grinding control method for avoiding workpiece collision proposed by the present application in combination with the accompanying drawings and implementation examples. It should be understood that the specific implementation examples described herein are only used to explain the present application and are not used to limit the present application.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs.

[0020] Please refer to Figure 1 , which shows the flowchart of the steps of an eccentric shaft grinding control method for avoiding workpiece collision provided by an embodiment of the present application. The method includes the following steps: Step 1, during the grinding process of the eccentric shaft on the processing machine tool, obtain the actual rotational speed of the grinding wheel at each moment within a preset local time period before the current moment in real time, and the actual feed rate of the grinding wheel at the current moment.

[0021] When the machine tool grinds the eccentric shaft and calculates the trajectory of the eccentric shaft by the method of tangent point tracking, since the radial wear of the grinding wheel during the grinding process causes the radius of the grinding wheel to continuously decrease with the processing process and the change value is large, it is difficult to coincide the position of the theoretically calculated grinding point and the actual grinding point, resulting in a deviation in the feed rate of the grinding wheel, thereby affecting the machining accuracy of the eccentric shaft part.

[0022] Set the theoretical rotational speed of the grinding wheel to 1800 r / min, and the rotational speed of the eccentric shaft to 10 r / min. As other implementation manners, the implementer can set according to the actual processing process, and this embodiment does not make special restrictions on this. Thus, start the processing machine tool and install a rotational speed sensor on the grinding wheel for processing the eccentric shaft. Since the rotational speed of the eccentric shaft is 10 r / min, collect the actual rotational speed of the grinding wheel at each moment in real time, and perform denoising processing and normalization processing on all the collected data.

[0023] In this embodiment, the acquisition frequency of the rotational speed sensor is 100 Hz. As other implementation manners, the implementer can set it according to the actual situation. Secondly, the Savitzky-Golay filtering algorithm is used for denoising processing. Among them, the Savitzky-Golay filtering algorithm is a well-known technology and will not be elaborated here. As other implementation manners, the implementer can adopt other methods of existing technologies, such as the Kalman filtering algorithm, etc. This embodiment does not make special restrictions on this.

[0024] Secondly, divide the actual rotational speeds at each moment within a preset local time period before the current moment into multiple grinding cycles. Number each moment within each grinding cycle starting from the value 1. Denote the moments corresponding to the same serial number within all grinding cycles as the moments of each cycle. It should be noted that for the convenience of understanding, scale all the moments within 1 minute before the current moment to 8 moments, which are respectively . Assume that they are divided into two grinding cycles, denoted as and respectively. Then all the moments within the grinding cycle are ; all the moments within the grinding cycle are . Number the moments within the grinding cycle starting from the value 1. The moment corresponds to the serial number 1, the moment corresponds to the serial number 2, the moment corresponds to the serial number 3, and the moment corresponds to the serial number 4. Number the moments within the grinding cycle starting from the value 1 as well. The moment corresponds to the serial number 1, the moment corresponds to the serial number 2, the moment corresponds to the serial number 3, and the moment

[0025] In addition, the PID (proportion integration differentiation) controller in the processing machine tool obtains the actual feed rate of the grinding wheel in real time at the current moment. In this embodiment, record the time for the eccentric shaft to rotate one circle as a grinding cycle. Secondly, the preset local time period is 1 minute. Since the rotational speed of the eccentric shaft is set to 10 r / min, there will be 10 grinding cycles within 1 minute. As other implementation manners, the implementer can set it according to the actual situation.

[0026] So far, the actual rotational speed and the actual feed rate of the grinding wheel are obtained in real time.

[0027] Step 2: Analyze the differences and the change trends of the actual rotational speeds corresponding to different grinding cycles at the moments of each cycle, and calculate the rotational speed change amounts at the moments of each cycle. Determine the friction balance degree of the grinding wheel at the current moment based on the change characteristics of the extreme points of the rotational speed change amounts at all the moments of each cycle and the number of extreme points.

[0028] Further, the flowchart of the method for obtaining the friction balance degree of the grinding wheel at the current moment provided by the embodiments of the present application is as Figure 2 shown.

[0029] During the grinding process of the eccentric shaft by the grinding wheel, since the eccentric part of the eccentric shaft is non-circular, its geometric shape is complex and there is an eccentricity. Therefore, the position of the contact point between the grinding wheel and the eccentric shaft is not fixed. The contact point is the tangent point or grinding point between the grinding wheel and the eccentric shaft. Since the position of the tangent point changes continuously during the grinding process, the normal vector at the tangent point also changes accordingly, which makes it difficult to keep the frictional force between the grinding wheel and the eccentric shaft constant, thereby affecting the stability of the grinding process and the machining quality.

[0030] Based on the above analysis, since the position of the tangent point is constantly changing, the frictional force between the grinding wheel and the eccentric shaft is also constantly changing, which makes the acceleration of the grinding wheel also constantly changing. In the most ideal case, the acceleration of the grinding wheel shows a periodic change, and then the rotational speed of the grinding wheel also shows a periodic change. When actually grinding the eccentric shaft, due to the grinding of the surface material of the eccentric shaft and the wear of the grinding wheel, the feed rate of the grinding wheel will decrease, resulting in a decrease in the frictional force between the grinding wheel and the eccentric shaft, thereby increasing the acceleration of the grinding wheel and increasing the rotational speed of the grinding wheel. Thus, by calculating the change amount of the rotational speed of the grinding wheel through the change situation of the actual rotational speed at different grinding cycles at the same periodic moment, specifically: Select the actual rotational speeds corresponding to all grinding cycles at each periodic moment to form a periodic sequence of each periodic moment; Calculate the mean value of the differences between all any two elements in the periodic sequence, denoted as the relative difference amount; In this embodiment, calculate the mean value of the absolute values of the differences between all any two elements in the periodic sequence, denoted as the relative difference amount.

[0031] Calculate the first-order difference sequence for the periodic sequence, and count the number of positive and negative elements in the first-order difference sequence; Denote the difference between the number of positive values and the number of negative values as the quantity difference; Take the ratio of the quantity difference to the relative difference amount as the change amount of the rotational speed at each periodic moment; It should be noted that the larger the positive difference in quantity, the more times the rotational speed of the grinding wheel increases than decreases, indicating that the frictional force between the grinding wheel and the eccentric shaft gradually decreases. This means that the grinding wheel is more sensitive to the adjustment of the grinding force during the entire grinding cycle, resulting in a better grinding effect on the eccentric shaft and a faster grinding speed. The larger the relative difference, the greater the difference in the actual rotational speed at the same moment between different grinding cycles, indicating that the interaction between the grinding wheel and the eccentric shaft during grinding cannot ensure the stability of the grinding rotational speed. The greater the resulting change in rotational speed, the worse the grinding effect of the grinding wheel on the eccentric shaft. If the grinding efficiency of the grinding wheel is high and the rotational speed is stable, and the grinding effect of the grinding wheel on the eccentric shaft is good, then the degree of wear of the grinding wheel is correspondingly higher, and the feed rate should be adjusted accordingly in the future.

[0032] Furthermore, during the grinding process of the eccentric shaft, the offset shaft rotates according to the center shaft. Since the center of the offset shaft and the center of the center shaft are not on the same straight line, during the rotation of the eccentric shaft, within one grinding cycle, the rotational speed changes at different cycle times will show a state with one maximum value and one minimum value. When there are multiple maximum and minimum values, it indicates an unstable state during the grinding of the eccentric shaft. Therefore, by analyzing the change trend of the rotational speed change amount at different cycle times and calculating the friction balance degree, specifically: Obtain the extreme points of the rotational speed change amount at all cycle times; In this embodiment, an extreme point detection algorithm is used to obtain the extreme points. Among them, the extreme point detection algorithm is a well-known technology and will not be elaborated here.

[0033] Calculate the maximum value of the rotational speed change amount corresponding to all extreme points; Count the number of all extreme points; record the difference between the number and the preset ideal number as the quantity deviation; In this embodiment, since within one grinding cycle, the rotational speed change at different cycle times should show a state with one maximum value and one minimum value, the preset ideal number is set to 2.

[0034] Take the ratio of the maximum value to the quantity deviation as the friction balance degree of the grinding wheel at the current moment; It should be understood that when calculating the ratio, to avoid the denominator being 0, a preset value greater than 0 is added to the denominator. In this embodiment, the preset value greater than 0 is taken as 1. As other implementation methods, the implementer can set it according to the actual situation.

[0035] It should be noted that the larger the maximum value is, the better the grinding effect of the grinding wheel on the eccentric shaft during the grinding process. However, the larger the wear amount of the material between the eccentric shaft and the grinding wheel is, the insufficient feed amount between the eccentric shaft and the grinding wheel will be, resulting in a decrease in the frictional force between the eccentric shaft and the grinding wheel. At this time, the feed amount of the grinding wheel should be increased to ensure that the grinding wheel can provide sufficient grinding force to grind the eccentric shaft. The smaller the quantity deviation is, the more the change state of the rotational speed change conforms to the ideal situation, the smaller the collision between the grinding wheel and the eccentric shaft, and the larger the obtained friction balance degree. This indicates that while avoiding multiple collisions between the grinding wheel and the eccentric shaft, the grinding of the eccentric shaft is relatively high, so that a relatively balanced state can be achieved, the grinding effect of the grinding wheel is better, and the resulting wear is more serious. Subsequently, the feed amount of the grinding wheel should be increased more, the machining accuracy and surface quality of the eccentric wheel should be increased, and finally the service performance and service life of the eccentric shaft should be improved.

[0036] Thus, the friction balance degree of the grinding wheel at the current moment is obtained.

[0037] Step 3: Based on the deviation degree of the actual rotational speeds at different moments within the preset local time period at the current moment, and in combination with the friction balance degree, the wear coefficient of the grinding wheel at the current moment is obtained.

[0038] During the grinding process of the eccentric shaft, the wear of the grinding wheel will lead to insufficient feed amount. At this time, although the rotational speed of the grinding wheel will increase, due to the frictional force between the grinding wheel and the eccentric shaft, the actual rotational speed of the grinding wheel during the grinding of the eccentric shaft is always less than its no-load rotational speed. Therefore, the smaller the difference between the rotational speed of the grinding wheel during the grinding process and its no-load rotational speed is, the further the frictional force during the grinding process is reduced, which means that the wear of the grinding wheel is aggravated and the problem of insufficient feed amount is more significant. In this case, it is necessary to adjust the feed amount of the grinding wheel in a timely manner to ensure that the grinding wheel has sufficient grinding force on the eccentric shaft and ensure the precision machining of the eccentric shaft.

[0039] Based on the above analysis, by analyzing the deviation degree between the actual rotational speed and the no-load theoretical rotational speed at different moments, and in combination with the friction balance degree, the wear coefficient is calculated. Specifically: Calculate the average value of the differences between the actual rotational speeds at all moments within the preset local time period at the current moment and the preset theoretical rotational speed, and denote it as the rotational speed deviation. In this embodiment, the preset theoretical linear velocity is 1800 r / min. As other implementation manners, the implementer can set it according to the specific processing conditions, and this embodiment does not make special restrictions on this. Secondly, calculate the average value of the absolute values of the differences between the actual rotational speeds at all moments within the preset local time period at the current moment and the preset theoretical rotational speed, and denote it as the rotational speed deviation.

[0040] Take the normalized result of the ratio of the friction balance degree to the rotational speed deviation as the wear coefficient of the grinding wheel at the current moment. In this embodiment, the sigmoid function is used for normalization. The sigmoid function is a well-known technology and will not be elaborated here. As other implementation manners, implementers can adopt other methods of the prior art. For example, the tanh function, etc. This embodiment does not make special restrictions on this. Secondly, when calculating the ratio, to avoid the denominator being 0, a preset value greater than 0 is added to the denominator. In this embodiment, the preset value greater than 0 is taken as 1. As other implementation manners, implementers can set it by themselves according to the actual situation.

[0041] It should be noted that the smaller the rotational speed deviation is, the smaller the difference between the actual rotational speed and the theoretical rotational speed of idling is, indicating that the wear of the grinding wheel is more serious. At the same time, due to the increase in the periodic rotational speed fluctuation of the grinding wheel, the friction balance degree of the grinding wheel during the grinding of the eccentric shaft will increase. The larger the obtained wear coefficient is, the more significant the wear state of the grinding wheel is, and the smaller the frictional force between the grinding wheel and the eccentric shaft is. At this time, the grinding parameters should be adjusted to increase the feed rate of the grinding wheel to increase the grinding force of the grinding wheel on the eccentric shaft, thereby improving the machining accuracy and surface quality and ensuring the stability and consistency of the machining process.

[0042] Thus, the wear coefficient of the grinding wheel at the current moment is obtained.

[0043] Step 4: Based on the wear coefficient, determine the adjusted feed rate of the grinding wheel at the current moment, and combine the actual feed rate to control and adjust the feed rate of the grinding wheel through a control algorithm.

[0044] Furthermore, based on the wear coefficient, the feed rate of the grinding wheel at the current moment is adjusted. Specifically: The calculation formula for the adjusted feed rate of the grinding wheel at the current moment is: where, is the adjusted feed rate of the grinding wheel at the current moment , is the wear coefficient of the grinding wheel at the current moment , is the preset initial feed rate.

[0045] In this embodiment, the preset initial feed rate is taken as 0.02 mm. As other implementation manners, implementers can set it by themselves according to the actual situation.

[0046] It should be noted that during the grinding of the eccentric shaft, the wear of the grinding wheel is an inevitable phenomenon. The larger the wear coefficient, the higher the degree of wear of the grinding wheel. Intensified wear will lead to insufficient grinding force, thus affecting the grinding effect. In this case, it is necessary to increase the feed rate of the grinding wheel appropriately to ensure that there is sufficient friction between the grinding wheel and the eccentric shaft. By adjusting the feed rate of the grinding wheel, not only can the grinding efficiency be improved, but also the service life of the grinding wheel can be extended and the production cost can be reduced.

[0047] Calculate the difference between the actual feed amount of the grinding wheel at the current moment and the adjusted feed amount, and record it as the target deviation; In this embodiment, the difference between the actual feed amount of the grinding wheel at the current moment and the adjusted feed amount is calculated and recorded as the target deviation.

[0048] The target deviation is used as the input of a PID (proportion integration differentiation) control algorithm to control and adjust the feed amount of the grinding wheel; It should be noted that the PID control algorithm controls the motor driver to adjust the feed speed and position of the grinding wheel on the X-axis to ensure that the feed amount of the grinding wheel is close to the adjusted feed amount to achieve high-precision grinding processing. The PID control algorithm is a well-known technology and will not be described in detail here.

[0049] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0050] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0051] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several variations and improvements can still be made. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application all fall within the protection scope of the technical solution of the present application.

Claims

1. An eccentric shaft grinding control method for avoiding workpiece collision, characterized in that The method includes the following steps: During the grinding process of the eccentric shaft on a machining tool, the actual rotational speeds of the grinding wheel at each moment within a preset local time period before the current moment are obtained in real time, as well as the actual feed rate of the grinding wheel at the current moment; using the rotational speed condition of the eccentric shaft, all moments within the preset local time period are divided into multiple grinding cycles; each moment within each grinding cycle is numbered respectively, and the moments corresponding to the same serial number within all grinding cycles are denoted as the cycle moments; Analyze the difference situation and its change trend of the actual rotational speeds corresponding to different grinding cycles at each cycle moment, and calculate the rotational speed change amount at each cycle moment; determine the friction balance degree of the grinding wheel at the current moment through the change characteristics of the extreme points of the rotational speed change amounts at all cycle moments and the number situation of the extreme points; Based on the deviation degree of the actual rotational speeds at different moments within the preset local time period at the current moment, combined with the friction balance degree, obtain the wear coefficient of the grinding wheel at the current moment; Based on the wear coefficient, determine the adjusted feed rate of the grinding wheel at the current moment, combined with the actual feed rate, and control and adjust the feed rate of the grinding wheel through a control algorithm.

2. The eccentric shaft grinding control method for avoiding workpiece collision according to claim 1, characterized in that, The step of using the rotational speed condition of the eccentric shaft to divide all moments within the preset local time period into multiple grinding cycles includes: taking the time required for the eccentric shaft to rotate one week as a grinding cycle, and dividing all moments within the preset local time period into multiple grinding cycles.

3. A method for controlling the grinding of an eccentric shaft to avoid workpiece collision according to claim 1, characterized in that, The calculation of the rotational speed change amount at each cycle moment includes: Select the actual rotational speeds corresponding to all grinding cycles at each cycle moment to form a cycle sequence at each cycle moment; Calculate the mean value of the differences between all any two elements within the cycle sequence, and denote it as the relative difference amount; Analyze the difference situation between adjacent elements within the cycle sequence, and determine the quantity difference between the number of positive and negative differences among all adjacent elements; The rotational speed change amount is the ratio of the quantity difference to the relative difference amount.

4. A method for controlling the grinding of an eccentric shaft to avoid workpiece collision according to claim 3, characterized in that, The further determination process of the quantity difference is: Calculate the first-order difference sequence for the cycle sequence, and count the number of positive and negative elements within the first-order difference sequence; Denote the difference between the number of positive values and the number of negative values as the quantity difference.

5. A method for controlling the grinding of an eccentric shaft to avoid workpiece collision according to claim 1, characterized in that, The determination of the friction balance degree of the grinding wheel at the current moment includes: Obtain the extreme points of the rotational speed change amounts at all cycle moments; calculate the maximum value of the rotational speed change amounts corresponding to all extreme points; Count the number of all extreme points; denote the difference between the number and a preset ideal number as the quantity deviation; Negatively fuse the maximum value with the quantity deviation to obtain the friction balance degree of the grinding wheel at the current moment.

6. The eccentric shaft grinding control method for avoiding workpiece collision according to claim 5, characterized in that, The further determination method of the negative fusion is: calculate the ratio of the maximum value to the quantity deviation as the friction balance degree of the grinding wheel at the current moment.

7. A method for controlling the grinding of an eccentric shaft to avoid workpiece collision according to claim 1, characterized in that, The further measurement process of the deviation degree is: calculate the mean value of the differences between the actual rotational speeds at all moments within the preset local time period at the current moment and the preset theoretical rotational speed, and denote it as the rotational speed deviation.

8. A method for controlling the grinding of an eccentric shaft to avoid workpiece collision according to claim 7, characterized in that, The wear coefficient is the normalized result of the ratio of the friction balance degree to the rotational speed deviation.

9. A method for controlling the grinding of an eccentric shaft to avoid workpiece collision according to claim 1, characterized in that, The grinding wheel at the current moment The adjusted feed rate after adjustment The calculation formula is as follows: , where is the wear coefficient of the grinding wheel at the current moment , and is the preset initial feed rate.

10. A method for controlling the grinding of an eccentric shaft to avoid workpiece collision according to claim 1, characterized in that, The control and adjustment of the feed rate of the grinding wheel include: recording the difference between the actual feed rate of the grinding wheel at the current moment and the adjusted feed rate as the target deviation; using the target deviation as the input of the PID control algorithm to control and adjust the feed rate of the grinding wheel.

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