An eccentric shaft grinding control method for avoiding workpiece collision

Abstract

This application relates to the technical field of feed rate control, and specifically relates to an eccentric shaft grinding control method for avoiding workpiece collision. The method includes: during the grinding of the eccentric shaft by a processing machine tool, obtaining in real time the actual rotational speed of the grinding wheel at each moment within a preset local time period before the current moment, and the actual feed rate of the grinding wheel at the current moment; calculating the change in rotational speed; determining the friction balance degree of the grinding wheel at the current moment; obtaining the wear coefficient of the grinding wheel at the current moment, determining the adjusted feed rate of the grinding wheel at the current moment, and controlling and adjusting the feed rate of the grinding wheel through a control algorithm. This application adjusts the feed rate of the grinding wheel in real time, controls the feed rate of the grinding wheel more precisely, effectively avoids collisions and impacts during the grinding process, reduces the risk of damage to the workpiece and equipment, and improves the machining accuracy of the eccentric shaft.

Description

Technical Field

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

[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 techniques 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:

[0006] 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 in all grinding cycles are recorded as the moments of each cycle;

[0007] Analyze the difference situation and its change trend situation 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 value points of the rotational speed change amounts at all cycle moments and the number situation of the extreme value points;

[0008] 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;

[0009] Based on the wear coefficient, determine the adjusted feed rate of the grinding wheel at the current moment. Combine the actual feed rate and control the feed rate of the grinding wheel through a control algorithm.

[0010] Preferably, using the rotational speed condition of the eccentric shaft, divide all moments within a preset local time period into multiple grinding cycles, including: 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.

[0011] Preferably, calculating the rotational speed change amount at each cycle moment includes:

[0012] Select the actual rotational speeds corresponding to all grinding cycles at each cycle moment to form a cycle sequence for each cycle moment;

[0013] Calculate the average value of the differences between all any two elements within the cycle sequence, denoted as the relative difference amount;

[0014] 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;

[0015] The rotational speed change amount is the ratio of the quantity difference to the relative difference amount.

[0016] Preferably, the further determination process of the quantity difference is:

[0017] Calculate the first-order difference sequence for the cycle sequence, and count the number of elements that are positive and negative respectively within the first-order difference sequence;

[0018] Denote the difference between the number of positive values and the number of negative values as the quantity difference.

[0019] Preferably, determining the friction balance degree of the grinding wheel at the current moment includes:

[0020] 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;

[0021] Count the number of all extreme points; denote the difference between the number and the preset ideal number as the quantity deviation;

[0022] Perform negative fusion on the maximum value and the quantity deviation to obtain the friction balance degree of the grinding wheel at the current moment.

[0023] Preferably, 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.

[0024] Preferably, the further measurement process of the deviation degree is as follows: 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, which is denoted as the rotational speed deviation.

[0025] Preferably, the wear coefficient is the normalized result of the ratio of the friction balance degree to the rotational speed deviation.

[0026] Preferably, at the current moment the feed rate after adjustment has the following calculation formula: , where is the wear coefficient of the grinding wheel at the current moment , and is the preset initial feed rate.

[0027] 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.

[0028] This application has at least the following beneficial effects:

[0029] This application analyzes the differences in the actual rotational speeds corresponding to different grinding cycles at each cycle moment, calculates the change in rotational speed. The beneficial effect is that it takes into account 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; determines the friction balance degree of the grinding wheel at the current moment. The beneficial effect is that it takes into account 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, illustrates the adjustment of the feed rate of the grinding wheel, so as to avoid subsequent collision and severe vibration between the grinding wheel and the workpiece, which affects the machining quality of the surface of the eccentric shaft, and can further reflect the wear condition of the grinding wheel; secondly, obtains the wear coefficient of the grinding wheel at the current moment. The beneficial effect is that it takes into account 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 illustrates the significant situation of the wear of the grinding wheel, so as to judge whether it is necessary to increase the feed rate of the grinding wheel in the future to ensure that the grinding wheel has sufficient grinding force on the eccentric shaft; determines the adjusted feed rate of the grinding wheel at the current moment, combines the actual feed rate, and controls and adjusts the feed rate of the grinding wheel through a control algorithm. The beneficial effect is that compared with the traditional method, the feed rate is adjusted in real time according to the wear degree of the grinding wheel, solves the situation of insufficient or excessive feed rate caused by the wear of the grinding wheel, controls the feed rate of the grinding wheel more accurately, 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 needs of high-precision industrial production, and provides higher quality assurance for subsequent assembly and use. Brief Description of the Drawings

[0030] The following further elaborates in detail on a method for controlling the grinding of an eccentric shaft to avoid workpiece collision in this application with reference to the accompanying drawings.

[0031] Figure 1 It is a 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;

[0032] Figure 2 It is a flowchart of the steps of a method for obtaining the friction balance degree of the grinding wheel at the current moment provided by an embodiment of this application. Detailed Description of the Specific Embodiment

[0033] In order to make the purpose, technical solution and advantages of this application clearer, the following further elaborates in detail on a method for controlling the grinding of an eccentric shaft to avoid workpiece collision proposed in this application with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs.

[0035] Please refer to Figure 1 , which shows a step flowchart 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:

[0036] Step 1, during the grinding process of the eccentric shaft on the 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, and the actual feed rate of the grinding wheel at the current moment is obtained.

[0037] When the machining tool grinds the eccentric shaft and calculates the trajectory of the eccentric shaft by the method of tangent point tracking, during the grinding process, due to the radial wear of the grinding wheel, the radius of the grinding wheel continuously decreases with the machining process, and the change value is large, making it difficult for the theoretically calculated grinding point and the actual grinding point to coincide, resulting in a deviation in the feed rate of the grinding wheel, thus affecting the machining accuracy of the eccentric shaft part.

[0038] 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 machining process, and this embodiment does not make special limitations thereto. Thus, start the machining tool and install a rotational speed sensor on the grinding wheel for machining the eccentric shaft. Since the rotational speed of the eccentric shaft is 10 r / min, the actual rotational speeds of the grinding wheel at each moment are collected in real time, and all the collected data are subjected to denoising processing and normalization processing.

[0039] 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 the existing technology, such as the Kalman filtering algorithm, etc. This embodiment does not make special limitations thereto.

[0040] Secondly, the actual rotational speeds at each moment within a preset local time period before the current moment are divided into multiple grinding cycles, and each moment within each grinding cycle is numbered starting from 1. The moments corresponding to the same serial number within all grinding cycles are recorded as the cycle moments;

[0041] It should be noted that for the convenience of understanding, all the moments within 1 min before the current moment are scaled to 8 moments, which are respectively , assuming that it is divided into two grinding cycles, which are respectively recorded as and , then All moments within one grinding cycle are ; All moments within one grinding cycle are , and respectively for within one grinding cycle the moments are numbered starting from the value 1, the moment corresponding to the serial number 1, the moment corresponding to the serial number 2, the moment corresponding to the serial number 3, the moment corresponding to the serial number 4; for within one grinding cycle the moments are also numbered starting from the value 1, the moment corresponding to the serial number 1, the moment corresponding to the serial number 2, the moment corresponding to the serial number 3, the moment corresponding to the serial number 4.

[0042] In addition, the PID (proportion integration differentiation) controller in the processing machine tool obtains the actual feed rate of the grinding wheel at the current moment in real time;

[0043] In this embodiment, the time for the eccentric shaft to rotate one circle is recorded as one grinding cycle. Secondly, the preset local time period is 1 min. Since the rotation speed of the eccentric shaft is set to 10 r / min, there will be 10 grinding cycles within 1 min. As other implementation manners, the implementer can set it according to the actual situation.

[0044] So far, the actual rotation speed and actual feed rate of the grinding wheel are obtained in real time.

[0045] Step 2, analyze the difference situation and change trend situation of the actual rotation speeds corresponding to different grinding cycles at each cycle moment, and calculate the rotation 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 value points of the rotation speed change amounts at all cycle moments and the number situation of the extreme value points.

[0046] Furthermore, the step flow chart 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 is as Figure 2 shown.

[0047] 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. This 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.

[0048] 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 change. 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 in different grinding cycles at the same periodic moment, specifically:

[0049] Select the actual rotational speeds corresponding to all grinding cycles at each periodic moment to form a periodic sequence of each periodic moment;

[0050] Calculate the mean value of the differences between all any two elements in the periodic sequence, denoted as the relative difference amount;

[0051] 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.

[0052] 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;

[0053] Denote the difference between the number of positive values and the number of negative values as the quantity difference;

[0054] Take the ratio of the quantity difference to the relative difference amount as the change amount of the rotational speed at each periodic moment;

[0055] It should be noted that the larger the positive difference in the quantity is, 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. Then, within the entire grinding cycle, the grinding wheel is more sensitive to the adjustment of the grinding force, the grinding effect of the grinding wheel on the eccentric shaft is better, and the grinding speed is faster. The larger the relative difference is, 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 the grinding process 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. It shows that the grinding efficiency of the grinding wheel is relatively high and the rotational speed is stable, and the better the grinding effect of the grinding wheel on the eccentric shaft, the higher the corresponding wear degree of the grinding wheel, and the more the feed rate should be adjusted subsequently.

[0056] 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 change in rotational speed at different cycle times and calculating the friction balance degree, specifically:

[0057] Obtain the extreme points of the change in rotational speed at all cycle times;

[0058] 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.

[0059] Calculate the maximum value of the change in rotational speed corresponding to all extreme points;

[0060] Count the number of all extreme points; record the difference between the number and the preset ideal number as the quantity deviation;

[0061] In this embodiment, since within one grinding cycle, the rotational speed changes at different cycle times should show a state with one maximum value and one minimum value, the preset ideal number is set to 2.

[0062] Take the ratio of the maximum value to the quantity deviation as the friction balance degree of the grinding wheel at the current moment;

[0063] 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.

[0064] 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, the greater the wear of the material between the eccentric shaft and the grinding wheel, the insufficient feed rate between the eccentric shaft and the grinding wheel, and the reduced friction between the eccentric shaft and the grinding wheel. At this time, the feed rate 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 quantitative deviation is, the more the change state of the speed change is in line with the ideal situation, the smaller the collision between the grinding wheel and the eccentric shaft, and the greater the resulting friction balance, indicating that the grinding of the eccentric shaft is higher while avoiding multiple collisions between the grinding wheel and the eccentric shaft, thereby achieving a relative balance state, making the grinding effect of the grinding wheel better, and the more serious the wear is, the more the feed rate of the grinding wheel should be increased in the future, the processing accuracy and surface quality of the eccentric wheel should be increased, and ultimately the performance and service life of the eccentric shaft will be improved.

[0065] At this point, the friction balance of the grinding wheel at the current moment is obtained.

[0066] Step 3: Based on the deviation degree of the actual rotation speed at different times within the preset local time period at the current moment and in combination with the friction balance, the wear coefficient of the grinding wheel at the current moment is obtained.

[0067] During the eccentric shaft grinding process, the wear of the grinding wheel will lead to insufficient feed. At this time, although the grinding wheel speed will increase, due to the friction between the grinding wheel and the eccentric shaft, the actual speed of the grinding wheel when grinding the eccentric shaft is always lower than its speed when idling. Therefore, the smaller the difference between the grinding wheel speed during the grinding process and the speed when idling, the further the friction in the grinding process is reduced, which means that the grinding wheel wear is aggravated and the problem of insufficient feed is more significant. In this case, it is necessary to adjust the grinding wheel feed in time to ensure that the grinding wheel has sufficient grinding force on the eccentric shaft and ensure the precision processing of the eccentric shaft.

[0068] Based on the above analysis, the deviation between the actual speed at different times and the theoretical speed of idling is analyzed, and the wear coefficient is calculated in combination with the friction balance, specifically:

[0069] Calculate the average of the differences between the actual speed at all moments in the preset local time period at the current moment and the preset theoretical speed, and record it as the speed deviation;

[0070] In this embodiment, the preset theoretical linear speed is 1800 r / min. As other implementation methods, the implementer sets it according to the specific processing conditions. This embodiment does not impose any special restrictions on this. Secondly, the average of the absolute values of the differences between the actual speed at all moments in the preset local time period at the current moment and the preset theoretical speed is calculated and recorded as the speed deviation.

[0071] Take the normalization 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;

[0072] 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 existing technology, such as 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 according to the actual situation by themselves.

[0073] It should be noted that the smaller the rotational speed deviation, the smaller the difference between the actual rotational speed and the theoretical rotational speed during idling, 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, the more significant the wear state of the grinding wheel, and the smaller the frictional force between the grinding wheel and the eccentric shaft. 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.

[0074] Thus, the wear coefficient of the grinding wheel at the current moment is obtained.

[0075] 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.

[0076] Furthermore, based on the wear coefficient, adjust the feed rate of the grinding wheel at the current moment. Specifically:

[0077] The calculation formula for the adjusted feed rate of the grinding wheel at the current moment is:

[0078]

[0079] Wherein, 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.

[0080] In this embodiment, the preset initial feed rate is taken as 0.02 mm. As other implementation manners, implementers can set it according to the actual situation by themselves.

[0081] It should be noted that during the grinding process of the eccentric shaft, the wear of the grinding wheel is an inevitable phenomenon. The larger the wear coefficient, the higher the wear degree of the grinding wheel. The increased wear will lead to insufficient grinding force, thus affecting the grinding effect. In this case, it is necessary to appropriately increase the feed rate of the grinding wheel to ensure that there is sufficient frictional force 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.

[0082] Calculate the difference between the actual feed rate of the grinding wheel at the current moment and the adjusted feed rate, which is denoted as the target deviation.

[0083] In this embodiment, calculate the difference between the actual feed rate of the grinding wheel at the current moment and the adjusted feed rate, which is denoted as the target deviation.

[0084] Take the target deviation as the input of the PID (proportion integration differentiation) control algorithm to control and adjust the feed rate of the grinding wheel.

[0085] 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 rate of the grinding wheel is close to the adjusted feed rate, realizing high-precision grinding. Among them, the PID control algorithm is a well-known technology and will not be elaborated here.

[0086] It should be understood that although Figure 1 the steps in the flowchart of Figure 1 are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover,

[0087] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not conflict, it should be considered as the scope recorded in this specification.

[0088] 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 modifications and improvements can still be made. Therefore, any simple modifications, equivalent changes and decorations 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 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 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, denoted 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 between 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; Perform negative fusion of the maximum value and the quantity deviation to obtain the friction balance degree of the grinding wheel at the current moment; 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.

6. The eccentric shaft grinding control method for avoiding 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, denoted as the rotational speed deviation.

7. The eccentric shaft grinding control method for avoiding workpiece collision according to claim 6, characterized in that, The wear coefficient is the normalized result of the ratio of the friction balance degree to the rotational speed deviation.

8. 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 , is the preset initial feed rate.

9. 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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