Valve body-oriented inner hole positioning machining method and machining equipment

Abstract

The invention relates to the technical field of inner hole positioning and machining, in particular to an inner hole positioning and machining method and machining equipment for a valve body. Determining path jitter characteristics of each moment in the current cutting process by combining the cutting jitter characteristics of all acquisition moments in the previous cutting process; and determining the path difference weight at each moment in the cutting process, and correcting the feeding speed at each moment in the positioning and machining process of the inner hole of the valve body in combination with the feeding speed and the path jitter characteristic. The cutting vibration condition in the cutting process is monitored in real time, the feeding speed is adjusted in time, and the quality of a final finished product in the valve body inner hole positioning machining process is improved.

Description

Technical Field

[0001] This application relates to the technical field of internal hole positioning machining, and specifically relates to an internal hole positioning machining method and machining equipment for a valve body. Background Art

[0002] The valve body is the core component in various valves, and its function is to control the flow of fluids. The internal hole precision of the valve body directly affects the sealing performance and control flexibility of the valve. During the machining process of the valve body, the internal hole of the valve body is usually machined by milling. It cuts the material with a cutting tool and mills a cavity of the internal hole that meets the requirements inside the valve body to complete the machining of the valve body.

[0003] During the milling process, due to the continuous cutting collision between the cutting tool and the raw material, the cutting tool will vibrate continuously. The vibration of the cutting tool will cause uneven cutting inside the raw material, resulting in a rough internal hole surface and affecting the quality of the valve body. To eliminate the roughness of the internal hole surface caused by the vibration of the cutting tool, the traditional method is to detect the vibration of the cutting tool and adjust the feed rate of the cutting tool, thereby reducing the vibration of the cutting tool and improving the quality of the internal hole. However, the internal hole of the valve body usually has a complex geometric shape and high precision requirements. If the vibration data of the cutting tool is detected in real time, it is impossible to quickly adapt to the complex and changeable internal hole conditions in the valve body, resulting in a rough internal hole surface in the more complex parts of the valve body, reducing the quality of the final product during the internal hole positioning machining of the valve body. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide an internal hole positioning machining method and machining equipment for a valve body. The specific technical solutions adopted are as follows: In the first aspect, an embodiment of this application provides an internal hole positioning machining method for a valve body. The method includes the following steps: During each cutting process of the internal hole of the valve body, obtain the pressure data, the position coordinates of the cutting tool, and the feed speed at all acquisition times within a preset time period before each moment; Based on the pressure data at all acquisition times before each moment, obtain all decomposition vectors at each moment. Divide the neighborhood with any acquisition time in each decomposition vector as the center, and based on the average distribution of all elements in the neighborhood, determine the jitter energy of each decomposition vector at any acquisition time, and based on the distribution of the jitter energy of all decomposition vectors at any acquisition time, determine the cutting jitter characteristics at any acquisition time; Based on the position coordinates at any acquisition time and its previous acquisition time, determine the cutting direction at any acquisition time, and form a path feature vector at any acquisition time by combining the cutting jitter characteristics, position coordinates, and cutting direction at any acquisition time; Based on the differences in the path feature vectors between the previous acquisition moment at each moment during the current cutting process and any acquisition moment during the previous cutting process, determine the path feature weights at each moment during the current cutting process relative to any acquisition moment during the previous cutting process, and combine the cutting jitter characteristics of all acquisition moments during the previous cutting process to determine the path jitter characteristics at each moment during the current cutting process; Before each moment during the current cutting process, based on the differences in the path feature vectors between the adjacent and second - adjacent acquisition moments to that moment, determine the path difference weights at each moment during the current cutting process; Based on the preset feed speed and path difference weights at each moment during the current cutting process, as well as the path jitter characteristics at each moment and its previous acquisition moment, correct the feed speed at each moment during the positioning machining process of the valve inner hole.

[0005] Preferably, the acquisition process of all decomposition vectors at each moment is as follows: Take the pressure data of all acquisition moments before each moment as the input of the wavelet decomposition algorithm, and output all decomposition vectors at each moment.

[0006] Preferably, the method for determining the jitter energy of each decomposition vector at any acquisition moment is as follows: In each decomposition vector, take the mean value of all elements within the neighborhood of any acquisition moment as the jitter energy of each decomposition vector at any acquisition moment.

[0007] Preferably, the expression of the cutting jitter characteristic at any acquisition moment is: ; where represents the cutting jitter characteristic at acquisition moment i; represents the skewness of the jitter energy of all decomposition vectors at acquisition moment i; represents a preset constant greater than 0.

[0008] Preferably, the method for determining the cutting direction at a moment is as follows: Take the position coordinates of the previous acquisition moment of any acquisition moment as the starting point of the cutting motion vector, and take the position coordinates of any acquisition moment as the end point of the cutting motion vector to obtain the cutting motion vector at any acquisition moment. The cutting direction at any acquisition moment is the unit vector of the cutting motion vector at any acquisition moment.

[0009] Preferably, the path feature weight at each moment during the current cutting process relative to any acquisition moment during the previous cutting process is the normalized value of the reciprocal of the difference in the path feature vectors between the previous acquisition moment at each moment during the current cutting process and any acquisition moment during the previous cutting process.

[0010] Preferably, the method for determining the path jitter characteristics at each moment during the current cutting process is: Calculate the product of the path feature weight at each moment in the current cutting process relative to any acquisition moment in the previous cutting process and the cutting jitter feature at the corresponding acquisition moment in the previous cutting process, and use the sum of the products at each moment in the current cutting process relative to all acquisition moments in the previous cutting process as the path jitter feature at each moment in the current cutting process.

[0011] Preferably, the expression of the path difference weight at each moment in the current cutting process is: ; In the formula, represents the path difference weight at moment k in the current cutting process; represents the difference in the path feature vector between the acquisition moments adjacent to and next to moment k before moment k in the current cutting process.

[0012] Preferably, the correction of the feed speed at each moment in the process of positioning and machining the inner hole of the valve body includes: The corrected feed speed at moment k in the current cutting process has the following expression: ; In the formula, represents the preset feed speed at moment k in the current cutting process; represents the ratio of the path jitter feature at moment k in the current cutting process to the path jitter feature at the previous acquisition moment of moment k.

[0013] In a second aspect, an embodiment of the present application also provides an inner hole positioning machining device for a valve body, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of any one of the above-mentioned inner hole positioning machining methods for a valve body are implemented.

[0014] The present application has at least the following beneficial effects: By analyzing the vibration conditions of the cutting tool at different acquisition times before each moment in the historical cutting process, the cutting jitter characteristics at any acquisition time are determined. The beneficial effect is that by integrating the vibration data in the historical cutting process, the cutting conditions in the current cutting process are dynamically adjusted to reduce vibration, and the quality of the inner hole machining of the valve body is improved during the positioning machining process of the inner hole of the valve body. By analyzing the differences in cutting vibration characteristics, the position coordinates of the cutting tool, and the cutting direction between each moment in the current cutting process and all acquisition times in the historical cutting process, the path feature weight is determined. The beneficial effect is that by analyzing the differences in the cutting paths between the current moment and the historical moment, the reference value of the historical path features for the current cutting state is determined. While optimizing the cutting parameters, the quality and efficiency of the inner hole machining of the valve body are improved. By integrating the path feature weight and the cutting jitter characteristics, the path jitter characteristics at each moment in the current cutting process are constructed. The beneficial effect is that it reflects the vibration characteristics of the cutting tool in different postures, can control the cutting process more accurately, and improve the machining quality. By analyzing the degree of difference in the posture of the cutting tool between adjacent moments, the path difference weight at each moment in the current cutting process is determined. The beneficial effect is that the cutting parameters can be adjusted in a timely manner to improve the machining stability. Further, by integrating the path jitter characteristics, the path difference weight, and the preset feed speed at each moment in the current machining process, the speed at the current moment is corrected. By real-time monitoring the cutting vibration conditions during the cutting process and timely adjusting the feed speed, the quality of the final product in the inner hole positioning machining process of the valve body is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a flowchart of the steps of a method for inner hole positioning machining of a valve body provided by an embodiment of the present application; Figure 2 It is a schematic diagram of the process for obtaining cutting jitter characteristics provided by an embodiment of the present application; Figure 3 It is a flowchart of the process for obtaining path jitter characteristics provided by an embodiment of the present application; Figure 4 It is a schematic diagram of the process for extracting the corrected feed speed provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] To further elaborate on the technical means and effects adopted by this application to achieve the intended invention purpose, the following specifically describes, in conjunction with the accompanying drawings and preferred embodiments, a method and processing equipment for inner hole positioning processing of a valve body according to this application, including its specific implementation manner, structure, features, and effects. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs.

[0019] The following specifically describes the specific solutions of a method and processing equipment for inner hole positioning processing of a valve body provided by this application in conjunction with the accompanying drawings.

[0020] Please refer to Figure 1 , which shows a step flowchart of a method for inner hole positioning processing of a valve body provided by an embodiment of this application. The method includes the following steps: Step S1: During each cutting process of the inner hole of the valve body, obtain the pressure data, the position coordinates of the cutting tool, and the feed speed at all acquisition times within a preset time period before each moment.

[0021] In the control model of a numerical control machine tool, a fixed control path is usually given to the cutting tool to complete the cutting. During the cutting control process, it is necessary to control the feed amount of the cutting tool, that is, the moving amount of the cutting tool, to ensure the smoothness of the cutting surface of the cutting tool and avoid affecting the quality of the valve body. And during the cutting process, the measured pressure is the radial force exerted by the cutting tool on the inner hole material. When the pressure is small, it means that the cutting tool is far from the inner hole surface and the cutting force is small; when the pressure is large, it means that the cutting tool is close to the inner hole surface and the cutting force is large; the change in pressure can represent the vibration of the cutting tool during milling. The smaller the vibration, the more it can ensure the smoothness of the inner hole and improve the quality of the valve body.

[0022] Therefore, various data during the cutting process are obtained through the numerical control machine tool control system and the pressure sensor. Specifically, during each cutting process, obtain the pressure data, the position coordinates of the cutting tool, and the feed speed at all acquisition times at each moment and within a preset time period t before it, and set the data acquisition frequency to f. The position coordinates are in the form of a binary tuple, and the two elements in the binary tuple respectively represent the depth and height of the cutting tool in the valve body during the cutting process.

[0023] It should be noted that the values of the preset time period t and the data sampling frequency f are both set manually. In this embodiment, the value of the preset time period t is 1 s, and the value of the data sampling frequency f is 100 KHz. Implementers can also set them according to specific situations, and this embodiment does not make special restrictions.

[0024] Step S2: Based on the pressure data at all acquisition times before each time, obtain all decomposition vectors at each time. Divide a window centered on any acquisition time in each decomposition vector, and based on the average distribution of all elements in the window, determine the jitter energy of each decomposition vector at any acquisition time, and based on the distribution of the jitter energy of all decomposition vectors at any acquisition time, determine the cutting jitter characteristics at any acquisition time.

[0025] The traditional cutting tool control method eliminates the jitter of the cutting tool through adaptive control. Usually, it only adaptively adjusts the feed rate based on the real-time jitter intensity of the cutting tool. When the jitter is too large, the feed rate is reduced to reduce the jitter. The traditional cutting tool control method does not consider the influence of the cutting tool control path on the jitter. Therefore, at complex paths, the numerical control machine tool cannot quickly respond to the cutting tool jitter caused by the path change in time, and as a result, the surface of the valve body will be relatively rough.

[0026] Therefore, in this embodiment, by combining the path movement characteristics of the cutting tool in the previous cutting process of the current cutting process, the feed rate of the cutting tool during the cutting process is controlled. Specifically: (1) Take the pressure data at all acquisition times before each time as the input of the wavelet decomposition algorithm, and output all decomposition vectors at each time; Among them, the wavelet decomposition algorithm is a well-known technology in the field of signal processing. The lengths of all decomposition vectors output by this algorithm are the same, and its specific principle will not be elaborated here.

[0027] (2) Further, divide a neighborhood centered on any acquisition time in each decomposition vector, and use the mean value of all elements in the neighborhood as the jitter energy of each decomposition vector at any acquisition time.

[0028] It should be noted that the value of the radius of the neighborhood is set artificially. In this embodiment, the value of the neighborhood radius is 12. The implementer can also set it according to the specific situation, and this embodiment does not make special restrictions.

[0029] In addition, it should be understood that all decomposition vectors obtained by the wavelet decomposition algorithm have the same length as the vector composed of the original pressure data at all acquisition times. Therefore, it can be understood that each decomposition vector is also composed of element values at multiple acquisition times. Therefore, it can be understood that there are multiple decomposition vectors corresponding to any acquisition time.

[0030] It can be understood from the jitter energy of each decomposed vector at any acquisition moment that the larger the value of the jitter energy, the more likely the jitter of the cutting tool at the corresponding acquisition moment is caused by the cutting tool squeezing the cutting material to cause plastic deformation, and a larger feed rate should be maintained; on the contrary, the smaller the value of the jitter energy, the better the stability of the cutting tool at the corresponding acquisition moment.

[0031] (3) Further, based on the distribution of the jitter energy of all decomposed vectors at any acquisition moment, determine the cutting jitter characteristics at any acquisition moment, specifically: Cutting jitter characteristics at acquisition moment k The expression is: ; where represents the skewness of the jitter energy of all decomposed vectors at acquisition moment i; represents a preset constant greater than 0, which is used to prevent the calculation result from being 0, where the value of is set artificially. In this embodiment,

[0032] the value of

[0033] is 0. In the premise of ensuring that it does not overly affect the calculation result, the implementer can set it according to the specific situation by himself, and this embodiment does not make special restrictions.

[0034] Preferably, the schematic diagram of the process for obtaining the cutting jitter characteristics provided in this embodiment is as Figure 2 shown.

[0035] Specifically, if this cutting is the first machining use of the numerical control machine tool and there are no data of the previous cutting process, then this cutting still adopts the traditional cutting tool control method.

[0036] Step S3: Based on the position coordinates at any acquisition moment and its previous acquisition moment, determine the cutting direction at any acquisition moment, and form a path feature vector at any acquisition moment by combining the cutting jitter feature, position coordinates, and cutting direction at any acquisition moment; based on the differences in the path feature vectors between the previous acquisition moment at each moment during the current cutting process and any acquisition moment during the previous cutting process, determine the path feature weights at each moment during the current cutting process relative to any acquisition moment during the previous cutting process, and combine the cutting jitter features at all acquisition moments during the previous cutting process to determine the path jitter features at each moment during the current cutting process.

[0037] When machining the inner hole of the valve body using a cutting tool, different path directions of the cutting tool movement, different contact surfaces between the cutting tool and the material inside, and different cutting postures will all cause changes in the jitter characteristics of the cutting tool during the machining process. Therefore, in this embodiment, the cutting jitter characteristics under different paths are comprehensively analyzed to establish the connection between the posture of the cutting tool and the cutting jitter characteristics during the cutting path process, so as to more accurately control the cutting process, reduce machining errors, and improve the machining accuracy of the inner hole of the valve body. Specifically: (1) Since the cutting posture is related to the cutting path direction and the position of the cutting tool, the position coordinates of the previous acquisition moment at any acquisition moment are used as the starting point of the cutting motion vector, and the position coordinates at any acquisition moment are used as the end point of the cutting motion vector to obtain the cutting motion vector at any acquisition moment. The unit vector of the cutting motion vector at any acquisition moment is used as the cutting direction at any acquisition moment.

[0038] (2) Further, the cutting jitter feature, position coordinates, and cutting direction at any acquisition moment are combined to form a path feature vector at any acquisition moment. There are four attribute values in the path feature vector, namely the cutting jitter feature, the depth and height of the cutting tool inside the valve body during the cutting process in the position coordinates, and the cutting direction.

[0039] (3) Further, the normalized value of the reciprocal of the difference in the path feature vectors between the previous acquisition moment at each moment during the current cutting process and any acquisition moment during the previous cutting process is used as the path feature weight at each moment during the current cutting process relative to any acquisition moment during the previous cutting process.

[0040] It should be noted that there are many methods to measure the differences between vectors. In this embodiment, the Euclidean distance between the path feature vectors at each moment during the current cutting process and any acquisition moment during the previous cutting process is calculated to measure the differences between the path feature vectors. Implementers can also use other methods such as Mahalanobis distance and Manhattan distance that can measure the differences between vectors. Regarding the selection of methods for measuring the differences between vectors, this embodiment does not make special restrictions.

[0041] Among them, the calculation process of the Euclidean distance is a well-known technology, and its specific calculation steps will not be elaborated here.

[0042] Furthermore, according to the path feature weights of each moment in the current cutting process relative to any acquisition moment in the previous cutting process, it can be understood that the greater the path feature weight, the smaller the difference between the path feature vectors of the current moment in the current cutting process and the corresponding acquisition moment in the previous cutting process, indicating that the path features between the current moment in the current cutting process and the corresponding acquisition moment in the previous cutting process are more similar, and it shows that the cutting jitter characteristics at the corresponding acquisition moment are more valuable as a reference for the cutting jitter characteristics at this moment; on the contrary, the smaller the path feature weight, the greater the difference between the path feature vectors of the current moment in the current cutting process and the corresponding acquisition moment in the previous cutting process, indicating that the similarity degree of the path features between the current moment in the current cutting process and the corresponding acquisition moment in the previous cutting process is smaller, and it shows that the cutting jitter characteristics at the corresponding acquisition moment are less valuable as a reference for the cutting jitter characteristics at this moment.

[0043] (4) Further, calculate the product of the path feature weight of each moment in the current cutting process relative to any acquisition moment in the previous cutting process and the cutting jitter characteristics at the corresponding acquisition moment in the previous cutting process, and take the sum of the accumulations of the said products of each moment in the current cutting process relative to all acquisition moments in the previous cutting process as the path jitter characteristics of each moment in the current cutting process.

[0044] According to the path jitter characteristics of each moment in the current cutting process, it can be understood that the greater the path feature weight, the greater the cutting jitter characteristics, and the greater the obtained path jitter characteristics, indicating that the cutting jitter at the current moment in the current cutting process is more likely to be the cutting tool jitter caused by the plastic deformation of the cutting tool extruding the cutting material, and a larger feed rate should be maintained; on the contrary, the smaller the path feature weight, the smaller the cutting jitter characteristics, and the smaller the obtained path jitter characteristics, indicating that the cutting tool is relatively stable during the cutting process at the current moment in the current cutting process, and the current feed rate can be maintained.

[0045] Preferably, the flow chart of the process for obtaining the path jitter characteristics provided in this embodiment is as Figure 3 shown.

[0046] Step S4: Before each moment in the current cutting process, based on the difference between the path feature vectors between the adjacent and sub-adjacent acquisition moments to this moment, determine the path difference weights of each moment in the current cutting process; based on the feed rate, path jitter characteristics and path difference weights of the previous acquisition moment of each moment in the current cutting process, correct the feed rate of each moment in the process of positioning and machining the inner hole of the valve body.

[0047] A numerical control machine tool controls the feed amount of the cutting tool during the cutting process by controlling the feed speed of the cutting tool. Therefore, in this embodiment, by analyzing the differences in the path feature vectors between the adjacent and sub-adjacent acquisition times before each moment and the current moment during the current cutting process, and combining the feed speed, path jitter feature, and path difference weight at each moment and its previous acquisition moment during the current cutting process, the feed speed at each moment during the positioning machining process of the inner hole of the valve body is corrected. Specifically: (1) To improve the stability of the positioning machining process of the inner hole of the valve body, based on the differences in the path feature vectors between the adjacent and sub-adjacent acquisition times before each moment and the current moment during the current cutting process, the path difference weight at each moment during the current cutting process is determined to accurately control the cutting process. Specifically: The path difference weight at moment k during the current cutting process is expressed as: ; where represents the difference in the path feature vectors between the adjacent and sub-adjacent acquisition times before moment k during the current cutting process.

[0048] It should be noted that there are many methods to measure the difference between vectors. In this embodiment, the Euclidean distance between the path feature vectors between the adjacent acquisition time and the sub-adjacent acquisition time before moment k during the current cutting process is calculated to measure the difference between the path feature vectors. Implementers can also use other methods to measure the difference between vectors, such as the Manhattan distance or the DTW distance. There are no special restrictions on the selection of the method for measuring the difference between vectors in this embodiment.

[0049] From the path difference weights at each moment during the current cutting process, it can be understood that the greater the difference between the path feature vectors, the greater the path difference weight, indicating that the posture difference of the cutting tool between adjacent moments is greater, and the feed speed should be corrected according to the path jitter feature; conversely, the smaller the difference between the path feature vectors, the smaller the path difference weight, indicating that the posture difference of the cutting tool between adjacent moments is smaller, indicating that the cutting tool is relatively stable during the cutting process, and the feed speed can be appropriately adjusted.

[0050] (2) Further, based on the feed speed, path jitter feature, and path difference weight at the previous acquisition moment of each moment during the current cutting process, the feed speed at each moment during the positioning machining process of the inner hole of the valve body is corrected. Specifically: The corrected feed speed at moment k during the current cutting process is expressed as: ; where represents the preset feed speed at moment k during the current cutting process; represents the ratio of the path jitter feature at moment k and the path jitter feature at the previous acquisition moment of moment k during the current cutting process.

[0051] It should be noted that the method for obtaining the path jitter characteristics at any acquisition moment is the same as that for the path jitter characteristics at each moment.

[0052] In addition, it should be understood that the preset feed rate can be obtained through a numerical control machine tool. Generally, for rough machining, the feed rate may be between 0.1 and 0.5 mm / rev; for semi-finishing machining, the feed rate may be between 0.05 and 0.2 mm / rev; for finishing machining, the feed rate may be between 0.01 and 0.1 mm / rev. However, due to the differences in the machining materials and cutting tools, the preset feed rates given by the numerical control machine tool are also different at each moment. Therefore, specific data are not given in this example, and the implementer can refer to the specific machining process for setting.

[0053] Preferably, the schematic diagram of the process for extracting the corrected feed rate provided in this embodiment is as Figure 4 shown.

[0054] So far, in this embodiment, by taking the complex shape of the inner hole of the valve body into consideration in the feed rate of the cutting tool during the cutting process, adjusting the feed rate based on the analysis of the cutting posture of the cutting tool and the relationship between the cutting tool jitter, the problem of cutting tool jitter caused by the complex shape of the inner hole of the valve body is solved, and the quality of the final product in the positioning machining process of the inner hole of the valve body is improved.

[0055] Based on the same inventive concept as the above method, the embodiment of the present application also provides an inner hole positioning machining device for a valve body, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above methods for an inner hole positioning machining method for a valve body.

[0056] It should be noted that: the above sequence of the embodiments of the present application is only for description and does not represent the superiority or inferiority of the embodiments. And the above description of specific embodiments of this specification is made. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0057] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other. The key point of each embodiment is to illustrate the differences from other embodiments.

[0058] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for inner hole positioning machining of a valve body, characterized in that, The method includes the following steps: During each cutting process of the inner hole of the valve, obtain the pressure data, the position coordinates of the cutting tool, and the feed rate at all acquisition times within a preset duration before each moment; Based on the pressure data at all acquisition times before each moment, obtain all decomposition vectors at each moment. Divide the neighborhood centered on any acquisition time in each decomposition vector, and based on the average distribution of all elements in the neighborhood, determine the jitter energy of each decomposition vector at any acquisition time, and based on the distribution of the jitter energy of all decomposition vectors at any acquisition time, determine the cutting jitter characteristics at any acquisition time; Based on the position coordinates at any acquisition time and its previous acquisition time, determine the cutting direction at any acquisition time, and form the path feature vector at any acquisition time by combining the cutting jitter characteristics, position coordinates, and cutting direction at any acquisition time; Based on the difference in the path feature vectors between the previous acquisition time at each moment during the current cutting process and any acquisition time during the previous cutting process, determine the path feature weight at each moment during the current cutting process relative to any acquisition time during the previous cutting process, and combine the cutting jitter characteristics at all acquisition times during the previous cutting process to determine the path jitter characteristics at each moment during the current cutting process; Before each moment during the current cutting process, determine the path difference weight at each moment during the current cutting process based on the difference in the path feature vectors between the adjacent and the second adjacent acquisition times to that moment; Based on the preset feed rate and path difference weight at each moment during the current cutting process, as well as the path jitter characteristics at each moment and its previous acquisition time, correct the feed rate at each moment during the positioning machining process of the inner hole of the valve.

2. The inner hole positioning machining method for a valve body according to claim 1, characterized in that The process of obtaining all decomposition vectors at each moment is as follows: Take the pressure data at all acquisition times before each moment as the input of the wavelet decomposition algorithm, and output all decomposition vectors at each moment.

3. The inner hole positioning machining method for a valve body according to claim 1, characterized in that The method for determining the jitter energy of each decomposition vector at any acquisition time is as follows: In each decomposition vector, take the mean value of all elements within the neighborhood of any acquisition time as the jitter energy of each decomposition vector at any acquisition time.

4. A method for positioning and machining the inner hole of a valve body according to claim 1, characterized in that, The expression for the cutting jitter feature at any acquisition moment is as follows: ; where represents the cutting jitter feature at acquisition moment i; represents the skewness of the jitter energy of all decomposed vectors at acquisition moment i; represents a preset constant greater than 0.

5. A method for positioning and machining the inner hole of a valve body according to claim 1, characterized in that, The method for determining the cutting direction at any acquisition time is as follows: Take the position coordinates of the previous acquisition time at any acquisition time as the starting point of the cutting motion vector, and take the position coordinates at any acquisition time as the end point of the cutting motion vector to obtain the cutting motion vector at any acquisition time. The cutting direction at any acquisition time is the unit vector of the cutting motion vector at any acquisition time.

6. The inner hole positioning machining method for a valve body according to claim 1, characterized in that, The path feature weight at each moment during the current cutting process relative to any acquisition time during the previous cutting process is the normalized value of the reciprocal of the difference in the path feature vectors between the previous acquisition time at each moment during the current cutting process and any acquisition time during the previous cutting process.

7. A method for positioning and machining the inner hole of a valve body according to claim 1, characterized in that The method for determining the path jitter characteristics at each moment during the current cutting process is as follows: Calculate the product of the path feature weight at each moment in the current cutting process relative to any acquisition moment in the previous cutting process and the cutting jitter feature at the corresponding acquisition moment in the previous cutting process, and use the sum of the products at each moment in the current cutting process relative to all acquisition moments in the previous cutting process as the path jitter feature at each moment in the current cutting process.

8. A method for positioning and machining the inner hole of a valve body according to claim 1, characterized in that The expression for the path difference weight at each moment during the current cutting process is as follows: ; In the formula, represents the path difference weight at moment k during the current cutting process; represents the difference in path feature vectors between the acquisition moments adjacent and sub-adjacent to moment k before moment k during the current cutting process.

9. A method for positioning and machining the inner hole of a valve body according to claim 8, characterized in that, The correction of the feed speed at each moment in the positioning machining process of the inner hole of the valve body includes: The corrected feed rate at time k during this cutting process has the following expression: ; where represents the preset feed rate at time k during this cutting process; represents the ratio of the path jitter characteristic at time k to the path jitter characteristic at the previous acquisition time of time k during this cutting process.

10. An inner hole positioning machining device for a valve body, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, the steps of a method for positioning machining of the inner hole of a valve body according to any one of claims 1-9 are implemented.

Images