Rotation accuracy compensation method and system applicable to five-axis numerical control machining

Abstract

The present invention relates to the technical field of numerical control machine tools, and particularly to a rotation accuracy compensation method and system applicable to five-axis numerical control machining, including: obtaining the position state of the rotating axis of the five-axis machining table during operation and the environmental conditions, and obtaining the temperature and humidity expansion and contraction abnormality degree through the temperature and humidity change conditions of the environment during the operation of the rotating axis and the synchronous characteristics in time when the temperature and humidity are abnormal; analyzing the position state of the rotating axis to obtain the position deviation of the rotating axis, and combining it with the temperature and humidity expansion and contraction abnormality degree to obtain the temperature and humidity characteristic influence degree of the rotating axis; dividing the temperature data and humidity data into intervals, analyzing the distribution differences between temperature and humidity in different intervals, and combining the temperature and humidity characteristic influence degree to calculate the rotation linkage influence coefficient of the rotating axis, and further compensating the rotation accuracy of the rotating axis. The present invention effectively improves the compensation effect on the rotation accuracy of the rotating axis.

Description

Technical Field

[0001] The present invention relates to the technical field of numerically controlled machine tools, and particularly to a method and system for compensating rotational accuracy applicable to five-axis numerical control machining. Background Art

[0002] Three-axis CNC machining generally refers to the machining of the linear feed axes X, Y, and Z, which is suitable for machining some disk-shaped parts and can only machine one surface at a time; four-axis CNC machining adds a rotating axis on the basis of three axes, usually rotating 360° in the horizontal plane, and is suitable for machining some box-shaped parts; five-axis CNC machining adds another rotating axis on the basis of four axes, which can complete the entire machining process at one time, with high flexibility, high precision, high integration, and complete machining capabilities, and the corresponding cost and precision are also gradually increasing. Also, due to the high-precision requirements for machining materials in fields such as aviation, considering the safety of actual applications, at present, for machining parts with high-precision requirements, a five-axis numerical control system corresponding to five-axis CNC is usually selected for machining.

[0003] When using a five-axis numerical control system for machining parts, the two rotating axes contained therein will rotate to varying degrees according to a predetermined program. Due to the different offsets of the external temperature and humidity as well as the assembly positions of the internal rotating axes from the machining positions of the actual materials, it is impossible to accurately and effectively compensate according to the exact cause of the error. Summary of the Invention

[0004] The present invention provides a method and system for compensating rotational accuracy applicable to five-axis numerical control machining to solve the existing problems.

[0005] The method and system for compensating rotational accuracy applicable to five-axis numerical control machining of the present invention adopt the following technical solutions:

[0006] An embodiment of the present invention provides a method for compensating rotational accuracy applicable to five-axis numerical control machining, and the method includes the following steps:

[0007] Obtain the position state of the rotating axis and the environmental conditions during the operation of the five-axis machining table, and the environmental conditions include temperature data and humidity data;

[0008] For any rotating axis, evaluate the environmental stability through the temperature and humidity changes in the environment during the operation of the rotating axis, and combine the synchronous characteristics in time when the temperature and humidity are abnormal to obtain the temperature and humidity expansion and contraction abnormality degree of the any rotating axis; analyze the position state of the rotating axis to obtain the position deviation of the rotating axis, and combine it with the temperature and humidity expansion and contraction abnormality degree to obtain the temperature and humidity characteristic influence degree of the rotating axis;

[0009] Divide the temperature data and humidity data of any rotating axis during operation into intervals, analyze the distribution differences between temperature and humidity in different intervals, and combine the influence degrees of temperature and humidity characteristics to calculate the rotation linkage influence coefficient of the rotating axis;

[0010] Utilize the rotation linkage influence coefficient and the influence degrees of temperature and humidity characteristics of the rotating axis to obtain the error compensation coefficient of each rotating axis, thereby performing rotation accuracy compensation on the rotating axis.

[0011] Furthermore, the specific method for obtaining the temperature and humidity expansion and contraction abnormality degree of any rotating axis is as follows:

[0012] For any rotating axis, calculate the environmental stability coefficient of the any rotating axis according to the distribution characteristics of the temperature data and humidity data of the any rotating axis within a preset time range;

[0013] Obtain the corresponding abnormal duration and the time interval of the abnormality when temperature abnormality and humidity abnormality occur during the operation of the rotating axis, so as to calculate the over-limit temperature and humidity synchronization degree of the rotating axis;

[0014] Combine the environmental stability coefficient and the over-limit temperature and humidity synchronization degree of the any rotating axis to calculate the temperature and humidity expansion and contraction abnormality degree of the any rotating axis, and both the environmental stability coefficient and the over-limit temperature and humidity synchronization degree are positively correlated with the temperature and humidity expansion and contraction abnormality degree.

[0015] Furthermore, the specific method for calculating the environmental stability coefficient of the any rotating axis according to the distribution characteristics of the temperature data and humidity data of the any rotating axis within a preset time range includes the following:

[0016] For any rotating axis, obtain the variances of the temperature data and humidity data of the rotating axis within a preset time range, and denote them as temperature parameters and humidity parameters respectively;

[0017] Calculate the environmental stability coefficient of the any rotating axis according to the temperature parameters and humidity parameters, and the environmental stability coefficient is negatively correlated with both the temperature parameters and the humidity parameters.

[0018] Furthermore, the specific method for obtaining the corresponding abnormal duration and the time interval of the abnormality when temperature abnormality and humidity abnormality occur during the operation of the rotating axis, so as to calculate the over-limit temperature and humidity synchronization degree of the rotating axis, includes the following:

[0019] For any rotation axis, obtain the temperature data and humidity data of the any rotation axis that continuously exceed the preset temperature range and the preset humidity range within a preset time range, and denote them as the over-limit temperature data and the over-limit humidity data respectively. Denote the number of data included in the over-limit temperature data and the over-limit humidity data as the temperature over-limit quantity and the humidity over-limit quantity respectively; obtain the minimum interval time between the over-limit temperature data and the over-limit humidity data.

[0020] Calculate the over-limit temperature-humidity synchronization degree of the any rotation axis according to the temperature over-limit quantity, humidity over-limit quantity and minimum interval time of the any rotation axis.

[0021] Further, the specific method included in calculating the over-limit temperature-humidity synchronization degree of the any rotation axis according to the temperature over-limit quantity, humidity over-limit quantity and minimum interval time of the any rotation axis is as follows:

[0022] The specific calculation method of the over-limit temperature-humidity synchronization degree is as follows:

[0023]

[0024] Among them, is the over-limit temperature-humidity synchronization degree of the th rotation axis; is the rd temperature over-limit quantity of the th rotation axis, is the th humidity over-limit quantity of the th rotation axis, is the quantity of the temperature over-limit quantity of the th rotation axis, is the quantity of the humidity over-limit quantity of the th rotation axis, is the minimum interval time between the over-limit temperature data and the over-limit humidity data of the th rotation axis, is the absolute value function, is the minimum value function.

[0025] Further, the specific method included in analyzing the position state of the rotation axis to obtain the position deviation of the rotation axis and combining it with the temperature-humidity expansion and contraction abnormality degree to obtain the temperature-humidity characteristic influence degree of the rotation axis is as follows:

[0026] Install a laser sensor on each of the two rotation axes on the five-axis processing table, and preset a number of laser stop points on the plane where each rotation axis rotates alone. Record the number of times the laser irradiates on the laser stop points and the corresponding moments within a preset time range for each rotation axis, and denote them as the stop times and the stop moments respectively. Based on the stop moments, construct a laser stop moment sequence of the corresponding rotation axis on each laser stop point.

[0027] For any rotation axis, calculate the absolute value of the difference between the residence times corresponding to the laser residence points of the any rotation axis, which is denoted as the residence time difference between the laser residence points of the any rotation axis; calculate the variance of all elements in the forward difference sequence of the laser residence time sequence corresponding to any laser residence point of the any rotation axis, which is denoted as the offset parameter of the any laser residence point; obtain the absolute value of the difference between the offset parameters of different laser residence points of any rotation axis, which is denoted as the offset value between the laser residence points of the any rotation axis.

[0028] According to the residence time difference and the offset value of any rotation axis, calculate the error deviation degree of the any rotation axis. Both the residence time difference and the offset value are positively correlated with the error deviation degree. The error deviation degree of the rotation axis is used to describe the position deviation of the rotation axis.

[0029] According to the temperature and humidity expansion and contraction anomaly degree and the error deviation degree of any rotation axis, calculate the temperature and humidity characteristic influence degree of the any rotation axis. Both the temperature and humidity expansion and contraction anomaly degree and the error deviation degree are positively correlated with the temperature and humidity characteristic influence degree.

[0030] Further, the method for partitioning the temperature data and humidity data of any rotation axis during operation includes the following specific steps:

[0031] Use the normalized value of the temperature and humidity characteristic influence degree as the weight of the intermediate value of the preset temperature range and the preset humidity range, take the result obtained by weighted multiplication as the clustering center, and use the K-means clustering algorithm to cluster the temperature data and humidity data of any rotation axis within the preset time range respectively, to obtain several clustering clusters included in the temperature data and humidity data respectively; respectively mark the clustering cluster with the largest number of data points in the temperature data and humidity data as the local temperature range clustering cluster and the local humidity range clustering cluster.

[0032] Obtain the interval formed by the minimum temperature value and the maximum temperature value in all clustering clusters under the temperature data, which is denoted as the temperature interval of the corresponding clustering cluster. Denote the temperature interval of the local temperature range clustering cluster as the temperature main influence interval of the corresponding rotation axis, and denote the temperature intervals of the remaining clustering clusters that do not overlap with the temperature main influence interval as the temperature weak influence intervals of the corresponding rotation axis; and so on, obtain the humidity main influence interval and the humidity weak influence interval of any rotation axis.

[0033] Further, the method for analyzing the distribution difference between temperature and humidity in different intervals and combining the temperature and humidity characteristic influence degree to calculate the rotation linkage influence coefficient of the rotation axis includes the following specific steps:

[0034] Obtain the temperature and humidity independent characteristic values of the rotation axis.

[0035] Calculate the variance of the temperature data of each rotation axis in the corresponding main influence interval of temperature, denoted as the local temperature variance; calculate the variance of the humidity data of each rotation axis in the main influence interval of humidity, denoted as the local humidity variance;

[0036] The specific calculation method of the rotation linkage influence coefficient is as follows:

[0037]

[0038] where, is the rotation linkage influence coefficient of the th rotation axis; is the temperature and humidity characteristic influence degree of the th rotation axis, is the temperature and humidity independent eigenvalue of the th rotation axis, is the local temperature variance of the th rotation axis, is the local humidity variance of the th rotation axis, is the absolute value function, is the preset first hyperparameter, is the preset second hyperparameter.

[0039] Furthermore, the specific method included in the temperature and humidity independent eigenvalue is as follows:

[0040] Preset the temperature and humidity independent eigenvalue Y. If the overlap degree between the main influence intervals of temperature and humidity among different rotation axes is less than , merge the corresponding main influence intervals of temperature and humidity, and assign the temperature and humidity independent eigenvalue of each rotation axis to ; otherwise, assign it to , where , and , and are all preset parameters.

[0041] A rotation accuracy compensation system applicable to five-axis numerical control machining includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the rotation accuracy compensation method applicable to five-axis numerical control machining are implemented.

[0042] The beneficial effects of the technical solution of the present invention are as follows: In the embodiments of the present invention, the influence of temperature and humidity changes on the rotating shaft is considered. By analyzing the temperature and humidity expansion and contraction abnormality degree of the rotating shaft and combining the deviation situation of the rotating shaft position, the influence of environmental factors on the rotation accuracy in five-axis numerical control machining can be evaluated more accurately. The errors of the rotating shaft can be adjusted in real time according to different environmental conditions, and dynamic compensation can be performed according to the real-time environmental conditions, that is, by obtaining temperature and humidity data in real time and combining the operating state of the rotating shaft, which has the ability of dynamic adjustment, helps to timely respond to the influence brought by environmental changes, and avoids the machining accuracy problems caused by environmental factor fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for description in the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0044] Figure 1 It is a flowchart of the steps of the rotation accuracy compensation method applicable to five-axis numerical control machining of the present invention;

[0045] Figure 2 It is a three-dimensional model schematic diagram of a five-axis machining table;

[0046] Figure 3 It is an assembly schematic diagram of a laser sensor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation manners, structures, features, and effects of the rotation accuracy compensation method and system applicable to five-axis numerical control machining proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0049] The following specifically describes the specific solutions of the rotation accuracy compensation method and system applicable to five-axis numerical control machining provided by the present invention with reference to the accompanying drawings.

[0050] Please refer to Figure 1, which shows the flowchart of the steps of the rotation accuracy compensation method applicable to five-axis numerical control machining provided by an embodiment of the present invention. The method includes the following steps:

[0051] Step S001: Obtain the position state of the rotating axes and the environmental conditions during the operation of the five-axis machining table.

[0052] It should be noted that the five-axis machining table is a numerically controlled machine tool that can perform machining simultaneously in five different axial directions. Compared with traditional three-axis machining machine tools, the five-axis machining table has higher machining accuracy and the ability to machine complex shapes. Specifically, by combining three linear axes (X, Y, Z axes) and two rotating axes (A axis and B axis), the cutting tool can move more flexibly in space, thus enabling more complex workpiece machining, such as Figure 2 Shown is a schematic three-dimensional model of the five-axis machining table.

[0053] Specifically, to implement the rotation accuracy compensation method applicable to five-axis numerical control machining proposed in this embodiment, first, it is necessary to obtain the position state of the rotating axes and the environmental conditions during the operation of the five-axis machining table. The specific process is as follows:

[0054] First, install a laser sensor on each of the two rotating axes of the five-axis machining table, and preset laser stay points on the plane corresponding to each rotating axis when it rotates alone. Record the number of times the laser shines on the laser stay points and the corresponding moments within the preset time range for each rotating axis, and denote them as the stay times and stay moments respectively. Based on the stay moments, construct the laser stay moment sequence of the corresponding rotating axis at each laser stay point. As Figure 3 Shown is the assembly schematic diagram of the laser sensor.

[0055] It should be noted that in the embodiment of the present invention, the preset time range is 5 minutes according to experience, and the preset time range can be adjusted according to the actual situation. The embodiment of the present invention does not make specific limitations.

[0056] Then, install a temperature sensor and a humidity sensor in the machining workshop where the five-axis machining table is located to obtain temperature data and humidity data.

[0057] Finally, make each rotating axis rotate alone at a rotational speed of 20 rpm (revolutions per minute) for 5 minutes.

[0058] Thus far, through the above method, the laser stay moment sequence reflecting the position state of the rotating axes and the environmental data reflecting the environmental conditions, namely temperature data and humidity data, are obtained.

[0059] Step S002: For any rotation axis, evaluate the environmental stability based on the temperature and humidity changes in the environment during the operation of the rotation axis, and combine the synchronous characteristics of temperature and humidity anomalies in terms of time to obtain the temperature and humidity expansion and contraction anomaly degree of the arbitrary rotation axis; analyze the position state of the rotation axis to obtain the position deviation of the rotation axis, and combine it with the temperature and humidity expansion and contraction anomaly degree to obtain the temperature and humidity characteristic influence degree of the rotation axis.

[0060] It should be noted that when using a five-axis numerical control system for part processing, due to the high-precision requirements of the parts, the surface of the rotation axis, which changes slightly due to the external temperature and humidity, will cause a large range of errors during the rotation of the rotation axis. And usually, the two rotation axes in the five-axis processing table usually rotate simultaneously along their respective rotation directions. The motion states of the two rotation axes during simultaneous rotation are different from those of a single rotation axis during rotation, so the influence on the change of the processing position will also be different. Therefore, in the embodiments of the present invention, it is selected to analyze the temperature and humidity changes in the processing environment for the expandable and contractible state of the rotation axis, and combine the influence on the corresponding processing position during the rotation of different rotation axes to obtain the error compensation coefficient of each rotation axis, which is used to compensate the rotation angle of the rotation axis during the processing, thereby improving the rotation accuracy.

[0061] Specifically, in step S201, for any rotation axis, according to the distribution characteristics of the temperature data and humidity data of the arbitrary rotation axis within a preset time range, calculate the environmental stability coefficient of the arbitrary rotation axis, obtain the corresponding abnormal duration and the time interval of the anomaly when the temperature anomaly and humidity anomaly occur during the operation of the rotation axis, so as to calculate the over-limit temperature and humidity synchronization degree, and combine the environmental stability coefficient and the over-limit temperature and humidity synchronization degree of the arbitrary rotation axis to calculate the temperature and humidity expansion and contraction anomaly degree of the arbitrary rotation axis.

[0062] It should be noted that usually, when using a five-axis numerical control system for part processing, the temperature and humidity in the corresponding workshop will be dynamically regulated within a certain range of changes; for the temperature and humidity data within this range of changes, as the processing process progresses, if the change of the corresponding data is smoother, it means that the difference degree of the surface of the rotation axis changing due to thermal expansion and contraction by external factors is smaller, and it reflects that the probability of the rotation axis shifting in position due to thermal expansion and contraction and thus causing a large error in the rotation accuracy is lower.

[0063] Step S201.1: For any rotation axis, calculate the environmental stability coefficient of the arbitrary rotation axis according to the distribution characteristics of the temperature data and humidity data of the arbitrary rotation axis within a preset time range.

[0064] First, for any rotation axis, obtain the variances of the temperature data and the humidity data of the rotation axis within a preset time range, and denote them as the temperature parameter and the humidity parameter respectively.

[0065] Then, calculate the environmental stability coefficient of the arbitrary rotation axis according to the temperature parameter and the humidity parameter, and the environmental stability coefficient is negatively correlated with both the temperature parameter and the humidity parameter.

[0066] As an embodiment, the specific calculation method of the environmental stability coefficient is:

[0067]

[0068] Where is the environmental stability coefficient of the th rotation axis; is the temperature parameter of the th rotation axis, is the humidity parameter of the th rotation axis, is the exponential function with the natural constant as the base.

[0069] It should be noted that the environmental stability coefficient of the rotation axis is used to describe the stability of the environmental conditions of the rotation axis during operation. When the temperature and humidity change greatly during operation, the corresponding environmental conditions are unstable, then the values of the corresponding temperature parameter and humidity parameter will be large, and the environmental stability coefficient will be small.

[0070] Step S201.2: When the rotation axis has temperature anomalies and humidity anomalies during operation, obtain the corresponding anomaly duration and the time interval between anomalies, so as to calculate the over-temperature and over-humidity synchronization degree of the rotation axis.

[0071] It should be noted that in the machining workshop environment of five-axis numerical control, if the abnormal changes of the rotation axis are mainly caused by external factors, then for the temperature and humidity in the external environment, there will usually be a relatively synchronous abnormal change time period, so as to ensure that under the influence of external factors as much as possible, there is a large error change in the rotation accuracy of the rotation axis.

[0072] First, for any rotation axis, obtain the temperature data and humidity data that continuously exceed the preset temperature range and the preset humidity range of the arbitrary rotation axis within a preset time range, and denote them as over-temperature data and over-humidity data respectively. Denote the number of data included in the over-temperature data and the over-humidity data as the temperature over-limit quantity and the humidity over-limit quantity respectively; obtain the minimum interval time between the over-temperature data and the over-humidity data.

[0073] It should be noted that since the temperature data and humidity data are sequential data that change continuously and fluctuatingly, there may be multiple consecutive occurrences of exceeding the preset range (i.e., the preset temperature range and preset humidity range) when the temperature and humidity change. Therefore, when obtaining the temperature overlimit and humidity overlimit, there may be multiple temperature overlimits and humidity overlimits in the temperature data and humidity data.

[0074] It should be noted that generally, the temperature of the normal working environment of the rotating shaft is within the range, and the humidity of the normal working environment is within the range. Therefore, in the embodiments of the present invention, the preset temperature range is , and the humidity range is . Specifically, it can be adjusted according to the requirements in the actual production and processing process, and the embodiments of the present invention do not make specific limitations.

[0075] Then, according to the temperature overlimit, humidity overlimit, and minimum interval time of any rotating shaft, calculate the overlimit temperature and humidity synchronization degree of the any rotating shaft.

[0076] As an embodiment, the specific calculation method of the overlimit temperature and humidity synchronization degree is:

[0077]

[0078] Wherein, is the overlimit temperature and humidity synchronization degree of the th rotating shaft; is the th temperature overlimit of the th rotating shaft, is the th humidity overlimit of the th rotating shaft, is the number of temperature overlimits of the th rotating shaft, is the number of humidity overlimits of the th rotating shaft, is the minimum interval time between the overlimit temperature data and overlimit humidity data of the th rotating shaft, is the absolute value function, is the minimum value function.

[0079] It should be noted that if the temperature and humidity data exceeding the defined range are more synchronized, it indicates that the corresponding rotating shaft is more significantly affected by the external factors of temperature and humidity.

[0080] Step S201.3: For any rotating shaft, combine the environmental stability coefficient and overlimit temperature and humidity synchronization degree of the any rotating shaft to calculate the temperature and humidity expansion and contraction abnormality degree of the any rotating shaft.

[0081] It should be noted that the more unstable the temperature and humidity in the processing environment are, and the more obvious the influence of the external temperature and humidity on the rotating shaft is, it indicates that the change of temperature and humidity in the processing environment is more obvious for the morphological change of the rotating shaft due to thermal expansion and contraction, reflecting that the change of temperature and humidity in the processing environment is more likely to cause a relatively large surface expansion and contraction of the rotating shaft.

[0082] As an embodiment, the specific calculation method of the temperature and humidity expansion and contraction abnormality degree is as follows:

[0083]

[0084] Wherein, is the temperature and humidity expansion and contraction abnormality degree of the th rotating shaft; is the environmental stability coefficient of the th rotating shaft, is the over-limit temperature and humidity synchronization degree of the th rotating shaft.

[0085] Step S202, analyze the position state of the rotating shaft to obtain the position deviation of the rotating shaft, and combine it with the temperature and humidity expansion and contraction abnormality degree to obtain the temperature and humidity characteristic influence degree of the rotating shaft.

[0086] It should be noted that when the volume of the rotating shaft changes due to the physical property of thermal expansion and contraction, the laser sensor installed on the rotating shaft will also cause the laser position after rotation to shift due to the volume change of the rotating shaft, thereby changing the distribution state between the laser rain laser stop points irradiated on the plane at the corresponding moment.

[0087] It should be noted that under normal circumstances, due to the fixed rotation speed and sampling frequency, the irradiation of a rotating shaft on two corresponding laser stop points is the same. However, because different external temperatures and humidities will continuously affect the expansion and contraction degree of the rotating shaft, there will also be a certain difference in the number of times the laser irradiates on two corresponding laser stop points. Therefore, in the embodiment of the present invention, by analyzing the position information of the laser stop points, the error deviation degree of the rotating shaft is obtained to describe the position deviation situation of the rotating shaft.

[0088] First, for any rotating shaft, calculate the absolute value of the difference between the corresponding residence times of the laser stop points of the any rotating shaft, denoted as the residence time difference between the laser stop points of the any rotating shaft; calculate the variance of all elements in the forward difference sequence of the corresponding laser residence time sequence of any laser stop point of the any rotating shaft, denoted as the offset parameter of the any laser stop point; obtain the absolute value of the difference between the offset parameters of different laser stop points of any rotating shaft, denoted as the offset value between the laser stop points of the any rotating shaft.

[0089] Then, according to the difference in the number of stops and the offset value of any rotation axis, calculate the error deviation degree of the any rotation axis, and both the difference in the number of stops and the offset value are positively correlated with the error deviation degree.

[0090] As an embodiment, the specific calculation method of the error deviation degree is:

[0091]

[0092] Wherein, is the error deviation degree of the th rotation axis, represents the number of laser stop points corresponding to the th rotation axis, is the th and th laser stop points of the th rotation axis, is the th and th laser stop points of the th rotation axis, is the absolute value function.

[0093] It should be noted that if the influence of external temperature and humidity factors on the rotation axis is greater, the actual rotation error of the rotation axis is greater, indicating that the rotation error generated by the rotation axis is more likely to be mainly affected by external temperature and humidity, and it reflects that it is more necessary to consider compensating the rotation accuracy according to the corresponding temperature and humidity factors.

[0094] Finally, according to the temperature and humidity expansion and contraction abnormality degree and the error deviation degree of any rotation axis, calculate the temperature and humidity characteristic influence degree of the any rotation axis, and both the temperature and humidity expansion and contraction abnormality degree and the error deviation degree are positively correlated with the temperature and humidity characteristic influence degree.

[0095] As an embodiment, the specific calculation method of the temperature and humidity characteristic influence degree is:

[0096]

[0097] Wherein, is the temperature and humidity characteristic influence degree of the th rotation axis; is the temperature and humidity expansion and contraction abnormality degree of the th rotation axis, is the th rotation axis.

[0098] So far, according to the temperature and humidity changes in the processing environment, analyze the expandable and contractible state of the rotation axis, and divide several error temperature and humidity intervals.

[0099] Step S003: Divide the temperature data and humidity data during the operation of any rotation axis into intervals, analyze the distribution differences between temperature and humidity in different intervals, and calculate the rotation linkage influence coefficient of the rotation axis by combining the influence degrees of temperature and humidity characteristics.

[0100] Specifically, in step S301, divide the temperature data and humidity data by the influence degrees of temperature and humidity characteristics to divide the temperature main influence interval, temperature weak influence interval, humidity main influence interval, and humidity weak influence interval.

[0101] As an embodiment, the method for obtaining the temperature main influence interval, temperature weak influence interval, humidity main influence interval, and humidity weak influence interval includes:

[0102] First, use the normalized value of the influence degree of temperature and humidity characteristics as the weight of the intermediate value of the preset temperature range and preset humidity range, take the result obtained by weighted multiplication as the clustering center, and use the K-means clustering algorithm to cluster the temperature data and humidity data of any rotation axis within the preset time range respectively to obtain several clustering clusters included in the temperature data and humidity data; respectively record the clustering clusters with the largest number of data points in the temperature data and humidity data as the local temperature range clustering cluster and the local humidity range clustering cluster.

[0103] It should be noted that according to experience, the value of K in the K-means clustering algorithm is preset to 3, which can be adjusted according to the actual situation, and the embodiments of the present invention do not make specific limitations.

[0104] Then, obtain the interval formed by the minimum temperature value and the maximum temperature value in all clustering clusters of the temperature data, and record it as the temperature interval of the corresponding clustering cluster. Record the temperature interval of the local temperature range clustering cluster as the temperature main influence interval of the corresponding rotation axis, and record the temperature intervals of the remaining clustering clusters that do not overlap with the temperature main influence interval as the temperature weak influence intervals of the corresponding rotation axis; and so on, obtain the humidity main influence interval and humidity weak influence interval of any rotation axis.

[0105] It should be noted that usually, since the two rotation axes are of the same model, the corresponding material size requirements are basically the same, and the corresponding interval ranges mainly affected by temperature and humidity in the environment are also basically the same.

[0106] In addition, preset the temperature and humidity independent characteristic value Y. If the coincidence degree between the temperature and humidity main influence intervals of different rotation axes is less than , merge the corresponding temperature and humidity main influence intervals, and assign the temperature and humidity independent characteristic value of each rotation axis to ; otherwise, assign it to , where , and , and are all preset parameters.

[0107] It should be noted that according to experience, the preset parameters , and are 90%, 1, and 0.2 respectively, and their values can be adjusted according to specific circumstances. The embodiments of the present invention do not make specific limitations.

[0108] Step S302, calculate the rotational linkage influence coefficient of the th rotating shaft within the main influence range of temperature and humidity.

[0109] It should be noted that if the degrees of influence of temperature and humidity on different rotating shafts are similar, the thermal expansion and contraction states of the corresponding shaft bodies are more similar, indicating that when different rotating shafts perform combined rotation (that is, both rotating shafts start to rotate, not just one rotating shaft rotates alone), there is synchronization in the influence of the rotating shafts on the vibration of the overall rotation activity, and it reflects that the offset generated by the overall rotation is more likely to fluctuate. In addition, if the degrees of influence of temperature and humidity on different rotating shafts are not similar, it means that the rotating shaft is more likely to have limited space for telescopic change due to improper assembly of the rotating shaft. When different rotating shafts perform combined rotation, the synchronization of the influence of the rotating shafts on the vibration of the overall rotation activity is worse, and it reflects that the offset generated by the overall rotation is relatively more stable.

[0110] As an embodiment, the method for obtaining the rotational linkage influence coefficient of any rotating shaft includes:

[0111] First, calculate the variance of the temperature data of each rotating shaft within the corresponding main influence range of temperature, denoted as the local temperature variance; calculate the variance of the humidity data of each rotating shaft within the main influence range of humidity, denoted as the local humidity variance.

[0112] Then, according to the temperature and humidity characteristic influence degrees, temperature and humidity independent characteristic values, local temperature variance, and local humidity variance of different rotating shafts, calculate the rotational linkage influence coefficient of any rotating shaft within the main influence ranges of temperature and humidity respectively.

[0113] As an embodiment, the specific calculation method of the rotational linkage influence coefficient is:

[0114]

[0115] Among them, is the rotational linkage influence coefficient of the th rotating shaft; is the temperature and humidity characteristic influence degree of the th rotating shaft, is the The temperature and humidity independent eigenvalue of a rotating shaft, is the local temperature variance of the th rotating shaft, is the local humidity variance of the th rotating shaft, is the absolute value function, is a preset first hyperparameter, is a preset second hyperparameter.

[0116] It should be noted that, according to experience, the first hyperparameter is preset to 0.1 to avoid the situation of a zero denominator, and the second hyperparameter is preset to 0.6. The first hyperparameter and the second hyperparameter can be adjusted according to the actual situation, and the embodiments of the present invention do not make specific limitations.

[0117] And so on, obtain the rotational linkage influence coefficient of the rotating shaft in each weak temperature and humidity influence interval.

[0118] So far, when analyzing the combined influence of the position offset between the rotating shafts during the combined rotation of multiple rotating shafts in different error temperature and humidity intervals, the rotational linkage influence coefficient of each rotating shaft in the same error temperature and humidity interval is obtained.

[0119] Step S004: Use the rotational linkage influence coefficient of the rotating shaft and the temperature and humidity characteristic influence degree to obtain the error compensation coefficient of each rotating shaft, so as to compensate the rotational accuracy of the rotating shaft.

[0120] It should be noted that during the operation of the five-axis machining table, when the rotation angle of the rotating shaft has an error due to the influence of different factors, it is necessary to obtain the compensation value according to the influence of the corresponding factor on the rotating shaft and compensate the rotation angle to improve the rotational accuracy of the rotating shaft. Specifically, the magnitude of the rotational linkage influence coefficient of the rotating shaft reflects the cause of the corresponding error when the rotational accuracy of the rotating shaft is insufficient. When the rotational linkage influence coefficient is too large, it is usually affected by the external environmental conditions, that is, the rotation accuracy of the rotating shaft is in error due to the dominance of the external temperature and humidity. When the rotational linkage influence coefficient is too small, it is usually due to the problem of the assembly position of the internal rotating shaft, resulting in an error in the rotational accuracy. In other cases, it is the insufficient rotational accuracy caused by the combined influence of the external temperature and humidity conditions and the assembly position of the rotating shaft. Therefore, the embodiments of the present invention are based on the magnitude of the rotational linkage influence coefficient of the rotating shaft, and respectively obtain the error compensation coefficients in different situations through the temperature and humidity characteristic influence degree of the rotating shaft, the rotational linkage influence coefficient, and the temperature and humidity independent eigenvalue.

[0121] Specifically, as an embodiment, for any rotating shaft, the specific method for obtaining the error compensation coefficient of the any rotating shaft is:

[0122]

[0123] Among them, is the error compensation coefficient of the rotating shaft, is the influence degree of temperature and humidity characteristics of the rotating shaft, is the rotation linkage influence coefficient of the rotating shaft, is the temperature and humidity independent eigenvalue of the rotating shaft, is the normalization function.

[0124] Through the above steps, the compensation process for the rotation accuracy of the rotating shaft of the five-axis machining table is completed.

[0125] An embodiment of the present invention also provides a rotation accuracy compensation system applicable to five-axis numerical control machining. The system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the rotation accuracy compensation method applicable to five-axis numerical control machining are implemented.

[0126] The embodiment of the present invention considers the influence of temperature and humidity changes on the rotating shaft. By analyzing the temperature and humidity expansion and contraction abnormality of the rotating shaft and combining the position deviation of the rotating shaft, it can more accurately evaluate the influence of environmental factors on the rotation accuracy in five-axis numerical control machining, and adjust the error of the rotating shaft in real time according to different environmental conditions. It can perform dynamic compensation according to the real-time environmental conditions, that is, by adopting the method of obtaining temperature and humidity data in real time and combining the operating state of the rotating shaft, and has the ability of dynamic adjustment, which helps to timely respond to the influence brought by environmental changes and avoid machining accuracy problems caused by environmental factor fluctuations.

[0127] It should be noted that the model used in this embodiment is only used to represent the negative correlation relationship and restrict the result of the model output to be within the interval. Specifically in implementation, it can be replaced with other models with the same purpose. This embodiment only takes the model as an example for description and does not make specific limitations on it. Among them, refers to the input of the model.

[0128] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for compensating rotational accuracy applicable to five-axis numerical control machining, characterized in that, The method includes the following steps: Obtain the position state of the rotating axes of the five-axis machining table during operation and the environmental conditions, where the environmental conditions include temperature data and humidity data; For any rotating axis, evaluate the environmental stability based on the temperature and humidity changes in the environment during the operation of the rotating axis, and combine the synchronous characteristics in time when the temperature and humidity are abnormal to obtain the temperature and humidity expansion and contraction abnormality degree of the any rotating axis; analyze the position state of the rotating axis to obtain the position deviation of the rotating axis, and combine it with the temperature and humidity expansion and contraction abnormality degree to obtain the temperature and humidity characteristic influence degree of the rotating axis; Divide the temperature data and humidity data of any rotating axis during operation into intervals, analyze the distribution differences between temperature and humidity in different intervals, and combine the temperature and humidity characteristic influence degree to calculate the rotation linkage influence coefficient of the rotating axis; Utilize the rotation linkage influence coefficient and temperature and humidity characteristic influence degree of the rotating axis to obtain the error compensation coefficient of each rotating axis, so as to perform rotation accuracy compensation on the rotating axis; The method of analyzing the distribution differences between temperature and humidity in different intervals and combining the temperature and humidity characteristic influence degree to calculate the rotation linkage influence coefficient of the rotating axis includes the following specific method: Obtain the temperature and humidity independent characteristic values of the rotating axis; Calculate the variance of the temperature data of each rotating axis in the corresponding temperature main influence interval, denoted as the local temperature variance; calculate the variance of the humidity data of each rotating axis in the humidity main influence interval, denoted as the local humidity variance; The specific calculation method of the rotation linkage influence coefficient is: Among them, is the rotational linkage influence coefficient of the th rotating axis; is the temperature and humidity characteristic influence degree of the th rotating axis, is the temperature and humidity independent eigenvalue of the th rotating axis, is the local temperature variance of the th rotating axis, is the local humidity variance of the th rotating axis, is the absolute value function, is the preset first hyperparameter, is the preset second hyperparameter.

2. The rotational accuracy compensation method applicable to five-axis numerical control machining according to claim 1, wherein The specific method of obtaining the temperature and humidity expansion and contraction abnormality degree of the any rotating axis is: For any rotating axis, calculate the environmental stability coefficient of the any rotating axis according to the distribution characteristics of the temperature data and humidity data of the any rotating axis within a preset time range; Obtain the corresponding abnormal duration and the time interval of the abnormality when the temperature abnormality and humidity abnormality occur during the operation of the rotating axis, so as to calculate the over-limit temperature and humidity synchronization degree of the rotating axis; Combine the environmental stability coefficient and the over-limit temperature and humidity synchronization degree of the any rotating axis to calculate the temperature and humidity expansion and contraction abnormality degree of the any rotating axis, and both the environmental stability coefficient and the over-limit temperature and humidity synchronization degree are positively correlated with the temperature and humidity expansion and contraction abnormality degree.

3. The rotational accuracy compensation method applicable to five-axis numerical control machining according to claim 2, characterized in that The method of calculating the environmental stability coefficient of the any rotating axis according to the distribution characteristics of the temperature data and humidity data of the any rotating axis within a preset time range includes the following specific method: For any rotating axis, obtain the variance of the temperature data and the variance of the humidity data of the rotating axis within a preset time range, denoted as the temperature parameter and the humidity parameter respectively; Calculate the environmental stability coefficient of the any rotating axis according to the temperature parameter and the humidity parameter, and the environmental stability coefficient is negatively correlated with both the temperature parameter and the humidity parameter.

4. The rotational precision compensation method applicable to five-axis numerical control machining according to claim 2, characterized in that, The method of obtaining the corresponding abnormal duration and the time interval of the abnormality when the temperature abnormality and humidity abnormality occur during the operation of the rotating axis, so as to calculate the over-limit temperature and humidity synchronization degree of the rotating axis includes the following specific method: For any rotation axis, obtain the temperature data and humidity data of the any rotation axis that continuously exceed the preset temperature range and the preset humidity range within a preset time range, and record them as the over-limit temperature data and the over-limit humidity data respectively. Record the number of data included in the over-limit temperature data and the over-limit humidity data as the temperature over-limit quantity and the humidity over-limit quantity respectively; obtain the minimum interval time between the over-limit temperature data and the over-limit humidity data. Calculate the over-limit temperature-humidity synchronization degree of the any rotation axis according to the temperature over-limit quantity, humidity over-limit quantity and minimum interval time of the any rotation axis.

5. The rotational accuracy compensation method applicable to five-axis numerical control machining according to claim 4, characterized in that, The specific method for calculating the over-limit temperature-humidity synchronization degree of the any rotation axis according to the temperature over-limit quantity, humidity over-limit quantity and minimum interval time of the any rotation axis includes: The specific calculation method of the over-limit temperature-humidity synchronization degree is: Wherein, is the over-temperature and over-humidity synchronization degree of the th rotation axis; is the over-temperature quantity of the th rotation axis and the th temperature over-limit quantity, is the over-humidity quantity of the th rotation axis and the th humidity over-limit quantity, is the quantity of the over-temperature quantity of the th rotation axis, is the quantity of the over-humidity quantity of the th rotation axis, is the minimum interval time between the over-temperature data and the over-humidity data of the th rotation axis, is the absolute value function, is the minimum value function.

6. The rotation accuracy compensation method applicable to five-axis numerical control machining according to claim 1, characterized in that The specific method for analyzing the position state of the rotation axis to obtain the position deviation of the rotation axis and combining it with the temperature-humidity expansion and contraction abnormality degree to obtain the temperature-humidity characteristic influence degree of the rotation axis includes: Install a laser sensor on each of the two rotation axes on the five-axis processing table, and preset a number of laser staying points on the plane where each rotation axis rotates alone. Record the number of times the laser irradiates on the laser staying points and the corresponding moments within a preset time range for each rotation axis, and record them as the staying times and the staying moments respectively. Based on the staying moments, construct a laser staying moment sequence of the corresponding rotation axis at each laser staying point. For any rotation axis, calculate the absolute value of the difference between the staying times corresponding to the laser staying points of the any rotation axis, and record it as the staying time difference between the laser staying points of the any rotation axis; calculate the variance of all elements in the forward difference sequence of the laser staying moment sequence corresponding to any laser staying point of the any rotation axis, and record it as the offset parameter of the any laser staying point; obtain the absolute value of the difference between the offset parameters of different laser staying points of the any rotation axis, and record it as the offset value between the laser staying points of the any rotation axis. Calculate the error deviation degree of the any rotation axis according to the staying time difference and the offset value of the any rotation axis. Both the staying time difference and the offset value are positively correlated with the error deviation degree. The error deviation degree of the rotation axis is used to describe the position deviation of the rotation axis. Calculate the temperature-humidity characteristic influence degree of the any rotation axis according to the temperature-humidity expansion and contraction abnormality degree and the error deviation degree of the any rotation axis. Both the temperature-humidity expansion and contraction abnormality degree and the error deviation degree are positively correlated with the temperature-humidity characteristic influence degree.

7. The rotational accuracy compensation method applicable to five-axis numerical control machining according to claim 1, wherein The specific method for dividing the temperature data and humidity data of any rotation axis during operation includes: The value obtained by normalizing the influence degree of temperature and humidity characteristics is used as the weight of the intermediate value of the preset temperature range and the preset humidity range, and the result obtained by weighted multiplication is used as the clustering center. The K-means clustering algorithm is used to cluster the temperature data and humidity data of any rotation axis within the preset time range respectively, and several clustering clusters included in the temperature data and humidity data are obtained; the clustering clusters with the largest number of data points in the temperature data and humidity data are respectively recorded as the local temperature range clustering cluster and the local humidity range clustering cluster. The interval formed by the minimum temperature value and the maximum temperature value in all clustering clusters under the temperature data is obtained and recorded as the temperature interval of the corresponding clustering cluster. The temperature interval of the local temperature range clustering cluster is recorded as the temperature main influence interval of the corresponding rotation axis, and the temperature interval that does not overlap with the temperature main influence interval in the remaining clustering clusters is recorded as the temperature weak influence interval of the corresponding rotation axis; by analogy, the humidity main influence interval and the humidity weak influence interval of any rotation axis are obtained.

8. The rotational accuracy compensation method applicable to five-axis numerical control machining according to claim 1, characterized in that The specific method included in the temperature and humidity independent characteristic value is as follows: Preset the temperature and humidity independent eigenvalue Y. If the overlap degree between the main influence intervals of temperature and humidity between different rotation axes is less than , merge the corresponding main influence intervals of temperature and humidity, and assign the temperature and humidity independent eigenvalue of each rotation axis to be ; otherwise, assign it to be , where , and , and are all preset parameters.

9. A rotation accuracy compensation system applicable to five-axis numerical control machining, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the rotation accuracy compensation method applicable to five-axis numerical control machining according to any one of claims 1 to 8.

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