A high-precision numerical control machining method for offshore wind power rotor house annular workpieces

Abstract

The application relates to the technical field of numerical control machining, in particular to a high-precision numerical control machining method for a ring-shaped workpiece of a marine wind power rotor house, which comprises the following steps: determining the distortion deviation degree of a profile point in a first machining turn by using cutting force data and machining profile difference; determining a reference point corresponding to a position point of an instruction cutting track in a next machining turn of the first machining turn; determining a moving vector of the position point by using the position point, the reference point and the distortion deviation degree, and then adjusting the following instruction cutting track; determining the distortion deviation degree difference of the profile point by using the adjusted instruction cutting track of adjacent remaining machining turns, and then determining a current moving vector of a profile point in a current machining turn to be machined, and finally obtaining a current cutting speed of the current machining turn to be machined. According to the technical scheme, the real-time adjustment of the track during the machining of the ring-shaped workpiece is more accurate, and the machining precision of the ring-shaped workpiece is improved.

Description

Technical Field

[0001] This invention relates to the field of CNC machining technology, specifically to a high-precision CNC machining method for annular workpieces used in offshore wind turbine rotor houses. Background Technology

[0002] In the high-precision CNC machining of the ring-shaped workpiece for offshore wind turbine rotor houses, proper adjustment of the cutting trajectory can significantly improve machining accuracy and efficiency. By optimizing toolpath planning, machining errors can be reduced, tool life extended, and machining stability improved. Such adjustments help achieve high-precision, high-efficiency machining of complex parts, meeting the requirements of precision manufacturing for quality and cost control.

[0003] Traditional methods obtain the trajectory distortion at different positions by measuring the change in cutting force during machining. However, they do not take into account the interference of changes in the cutting allowance in the trajectory design on the distortion judgment. As a result, the obtained distortion does not match the actual situation, leading to insufficient machining accuracy for the ring-shaped workpiece of offshore wind turbine rotor house. Summary of the Invention

[0004] To address the technical problem of insufficient machining accuracy of existing machining methods for ring-shaped workpieces in offshore wind turbine rotor houses, the present invention aims to provide a high-precision CNC machining method for ring-shaped workpieces in offshore wind turbine rotor houses. The specific technical solution adopted is as follows:

[0005] This invention provides a high-precision CNC machining method for annular workpieces used in offshore wind turbine rotor houses, the method comprising:

[0006] By using cutting force data and the difference in machining contours between adjacent machining cycles, the degree of distortion deviation of contour points on the first machining cycle is determined;

[0007] If the distortion deviation is greater than the preset distortion threshold, determine the reference point corresponding to the position point of the cutting trajectory of the next machining cycle command in the first machining cycle;

[0008] The movement vector of the position point is determined by using the position point, reference point, and degree of distortion deviation. The position point is adjusted according to the movement vector to obtain the adjusted cutting trajectory of the remaining machining circles.

[0009] The difference in distortion deviation of the contour points is determined by the adjusted cutting trajectory of the adjacent remaining machining cycles, and the current movement vector of the contour point of the current number of machining cycles is determined by the difference in distortion deviation.

[0010] Using the current movement vector and the initial cutting rate, the current cutting rate for the current number of revolutions to be processed is obtained.

[0011] Furthermore, determining the degree of distortion deviation of the contour points on the first machining cycle by utilizing cutting force data and the machining contour differences of adjacent machining cycles includes:

[0012] Based on the cutting force time series data, the difference in cutting force between adjacent time moments is determined, and the target cutting force at the target time moment is determined.

[0013] The degree of contour distortion of the contour points at the target time is calculated using the difference in cutting force and the target cutting force.

[0014] The degree of distortion deviation of the contour points on the first processing cycle is determined by using the degree of contour distortion of the contour points on the first processing cycle and the difference in processing contours of the adjacent processing cycles.

[0015] Further, determining the degree of distortion deviation of the contour point on the first processing cycle by utilizing the degree of contour distortion of the contour point on the first processing cycle and the difference in processing contours of its adjacent processing cycles includes:

[0016] Determine the maximum distance between the contour points of the first processing cycle and the corresponding contour points of the previous adjacent processing cycle;

[0017] The distortion correction degree of the contour points in the first processing cycle is calculated by using the maximum distance difference between adjacent contour points in the first processing cycle and the degree of contour distortion.

[0018] The degree of distortion deviation of the contour points on the first machining cycle is calculated by using the degree of contour distortion and the degree of distortion correction on the first machining cycle.

[0019] Furthermore, when the distortion deviation exceeds a preset distortion threshold, determining the reference point corresponding to the position point of the cutting trajectory of the next machining cycle command in the first machining cycle includes:

[0020] If the distortion deviation is greater than the preset distortion threshold, determine multiple contour points corresponding to the position points of the cutting trajectory of the next machining cycle command in the first machining cycle.

[0021] The contour point with the largest distortion deviation among multiple contour points is used as the reference point corresponding to the position point of the cutting trajectory of the next machining cycle command.

[0022] Furthermore, the step of determining the movement vector of the position point using the position point, reference point, and distortion deviation degree, and adjusting the position point according to the movement vector to obtain the adjusted cutting trajectory of the remaining machining revolutions includes:

[0023] The direction of the line connecting the position point to the reference point is used as the direction of movement of the position point in the next processing cycle after the first processing cycle.

[0024] The movement vector is determined by the direction of movement and the degree of distortion deviation. The position points are adjusted according to the movement vector to obtain the adjusted cutting trajectory of the remaining machining revolutions.

[0025] Furthermore, determining the movement vector using the direction of movement and the degree of distortion deviation includes:

[0026] Using the distortion deviation of the reference point of the first processing cycle and the preset initial distance value, the moving distance of the position point of the next processing cycle is calculated, and the moving direction and moving distance are combined to obtain the moving vector.

[0027] Further, the step of determining the difference in distortion deviation of the contour points using the adjusted cutting trajectory of adjacent remaining machining cycles, and determining the current movement vector of the contour point of the current number of machining cycles using the difference in distortion deviation, includes:

[0028] The cutting process is performed using the adjusted cutting trajectory of each of the adjacent remaining machining cycles, and the contour points of the adjusted cutting trajectory are obtained.

[0029] Determine the degree of distortion deviation of each contour point and the difference in the degree of distortion deviation between contour points;

[0030] The current movement vector of the contour point of the current number of turns to be processed is determined by the difference in the degree of distortion deviation.

[0031] Furthermore, determining the current movement vector of the current contour point of the current number of cycles to be processed by utilizing the difference in distortion deviation includes:

[0032] Among adjacent remaining processing cycles, the remaining processing cycle number that is closer to the current processing cycle number is taken as the target cycle number;

[0033] By utilizing the differences in distortion deviation and the distortion deviation of the target circle number contour point, the current movement vector of the current circle number contour point to be processed is determined.

[0034] Further, the step of obtaining the current cutting rate for the current number of machining revolutions using the current movement vector and the initial cutting rate includes:

[0035] By adjusting the number of contour points based on the current movement vector and the current number of machining revolutions, the degree of reduction in the cutting rate for the current number of machining revolutions is determined.

[0036] The current cutting rate is calculated by using the degree of reduction in cutting rate and the initial cutting rate to determine the current number of machining revolutions.

[0037] Furthermore, the step of determining the degree of reduction in cutting rate for the current number of machining revolutions by adjusting the number of contour points using the current movement vector and the current number of machining revolutions includes:

[0038] Determine the proportion of the number of contour points to be adjusted in the current number of processing cycles to the total number of contour points.

[0039] By using the maximum movement vector in the current movement vector and the proportion of the adjustment quantity, the degree of reduction in the cutting rate for the current number of machining revolutions is calculated.

[0040] The present invention has the following beneficial effects:

[0041] This invention makes a preliminary judgment on the degree of deviation of the cutting trajectory based on the changes in cutting force during machining. It eliminates interference from changes in cutting force caused by trajectory settings by considering the cutting allowance when cutting the same position on the commanded trajectory in different revolutions, and corrects the trajectory deviation by considering the influence of morphological changes in the commanded cutting trajectory on the cutting force. It obtains the change in the commanded cutting trajectory for different numbers of cutting revolutions based on the abrupt changes in cutting force. Based on the trajectory deviation performance during machining, the machining rate is reasonably adjusted, making the real-time trajectory adjustment more accurate when machining ring-shaped workpieces, reducing tool wear, and improving the machining accuracy of ring-shaped workpieces for offshore wind turbine rotor houses. Attached Figure Description

[0042] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A flowchart illustrating the steps of a high-precision CNC machining method for annular workpieces in offshore wind turbine rotor housing, provided in one embodiment of the present invention;

[0044] Figure 2 This is a detailed flowchart of step S1 in a high-precision CNC machining method for annular workpieces of offshore wind turbine rotor housing provided in an embodiment of the present invention.

[0045] Figure 3 This is a detailed flowchart of step S13 in a high-precision CNC machining method for annular workpieces of offshore wind turbine rotor housing provided in an embodiment of the present invention.

[0046] Figure 4 This is a detailed flowchart of step S3 in a high-precision CNC machining method for annular workpieces of offshore wind turbine rotor housing provided in an embodiment of the present invention.

[0047] Figure 5This is a detailed flowchart of step S4 in a high-precision CNC machining method for annular workpieces of offshore wind turbine rotor housing provided in an embodiment of the present invention.

[0048] Figure 6 This is a detailed flowchart of step S5 in a high-precision CNC machining method for annular workpieces of offshore wind turbine rotor houses provided in an embodiment of the present invention.

[0049] Figure 7 This is a schematic diagram of the hardware operating environment of a high-precision CNC machining equipment for annular workpieces of offshore wind turbine rotor houses, as described in an embodiment of the present invention.

[0050] Figure 8 This is a schematic diagram of the displacement direction of the trajectory position point in the high-precision CNC machining method for the annular workpiece of offshore wind turbine rotor house according to the embodiment of the present invention;

[0051] Figure 9 This is a schematic diagram of the command cutting trajectory and the actual cutting trajectory in the high-precision CNC machining method for the ring-shaped workpiece of offshore wind turbine rotor house involved in the embodiment of the present invention. Detailed Implementation

[0052] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a high-precision CNC machining method for annular workpieces in offshore wind turbine rotor houses proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0054] Before proceeding with the following embodiments, the purpose of this invention and the main scenarios it addresses are briefly explained below.

[0055] The main objective of this invention is:

[0056] This invention makes a preliminary judgment on the degree of deviation of the cutting trajectory based on the changes in cutting force during machining. It corrects the deviation by considering the influence of morphological changes in the commanded cutting trajectory on the cutting force. It obtains the changes in the commanded cutting trajectory for different cutting revolutions based on the abrupt changes in cutting force at different cutting revolutions. Finally, it adjusts the machining rate appropriately based on the trajectory deviation observed during machining.

[0057] The main scenarios addressed by this invention can be:

[0058] In the high-precision CNC machining of ring-shaped workpieces for offshore wind turbine rotor houses, reasonable adjustment of the cutting trajectory can significantly improve machining accuracy and efficiency. Optimizing toolpath planning can reduce machining errors, extend tool life, and improve machining stability. Such adjustments help achieve high-precision, high-efficiency machining of complex parts, meeting the quality and cost control requirements of precision manufacturing. This invention makes a preliminary judgment on the degree of cutting trajectory deviation based on the changes in cutting force during machining. The deviation is corrected by considering the influence of morphological changes in the commanded cutting trajectory on the cutting force. The change in the commanded cutting trajectory for different cutting revolutions is obtained based on the abrupt changes in cutting force at different cutting revolutions. The machining rate is then reasonably adjusted based on the trajectory deviation behavior during machining.

[0059] The following description, in conjunction with the accompanying drawings, details a specific scheme for a high-precision CNC machining method for annular workpieces in offshore wind turbine rotor houses provided by the present invention.

[0060] Example 1:

[0061] For a high-precision CNC machining method for annular workpieces used in offshore wind turbine rotor houses provided by this invention, please refer to [link to relevant documentation]. Figure 1 The diagram illustrates a flowchart of a high-precision CNC machining method for annular workpieces in offshore wind turbine rotor houses, provided by an embodiment of the present invention.

[0062] The high-precision CNC machining method for the ring-shaped workpiece of offshore wind turbine rotor house includes:

[0063] Step S1: Using cutting force data and the difference in machining contours between adjacent machining cycles, determine the degree of distortion deviation of the contour points on the first machining cycle.

[0064] The complex curved surfaces on the ring-shaped workpiece (hereinafter referred to as "ring workpiece") of offshore wind turbine rotor house can be machined using the GSK 218M series CNC system or other CNC systems and machine tools.

[0065] A piezoelectric sensor is installed near the cutting point of the tool. The piezoelectric effect is used to convert the cutting force into an electrical charge output. After processing by a charge amplifier and a digital signal processor (DSP), the cutting force during machining can be monitored in real time to obtain the corresponding time series data, namely the cutting force time series data. It can also generate a cutting force change curve with the vertical axis as the magnitude of the cutting force and the horizontal axis as the time.

[0066] When machining high-precision ring-shaped workpieces, if the workpiece is partially suspended or not securely clamped, it is more prone to vibration and deformation, leading to irregular contours. For high-precision arcs, multi-circle cutting operations may be used. When the contour is irregular due to workpiece suspension or other reasons, subsequent cutting of the irregular area using the original cutting trajectory will result in larger cutting forces at the abnormally raised parts of the trajectory due to the increased cutting allowance. Furthermore, increased cutting resistance may cause further contour irregularities during the current cutting circle. Therefore, the location of contour irregularities should be determined based on the differences in cutting forces at different times during machining, in order to compensate for them later.

[0067] Specifically, please refer to Figure 2 Step S1 includes:

[0068] Step S11: Determine the difference in cutting force between adjacent time moments based on the cutting force time series data, and determine the target cutting force at the target time.

[0069] Step S12: Calculate the degree of contour distortion of the contour points at the target time using the difference in cutting force and the target cutting force.

[0070] In this embodiment, the difference in cutting force at adjacent times i-1 and i (where i is the target time, referring to any time) is obtained based on cutting force time series data. This refers to the difference in cutting force (positive or negative, the cutting force value at time i-1 minus the cutting force value at time i). The magnitude of the tool cutting force at time i is obtained. That is, the target cutting force.

[0071] The difference in cutting force between adjacent times i-1 and i The smaller the value, the greater the cutting force of the tool at time i. When the value is larger, the cutting force increases more suddenly when the tool reaches the contour position at time i, the cutting allowance increases sharply, and the contour position is more likely to experience prominent deformation.

[0072] This allows us to obtain the degree of contour distortion at the cutting position at time i. As mentioned above, Indicates the difference in cutting force. This represents the target cutting force. To avoid the denominator being zero, it is used as the denominator here. You can add any minimum value 'a', for example, a = 0.0000001.

[0073] The degree of contour distortion at all cutting positions at any given time can be obtained through the above operations.

[0074] Step S13: Determine the degree of distortion deviation of the contour points on the first processing cycle by using the degree of contour distortion of the contour points on the first processing cycle and the difference in processing contours of the adjacent processing cycles.

[0075] In this embodiment, when machining multiple turns at different positions in a ring-shaped workpiece, the machining accuracy and curve trend are not necessarily the same at different numbers of machining turns (hereinafter referred to as "number of turns"). This may lead to differences in the cutting allowance when machining at different positions, thereby interfering with the distortion judgment during the machining of the cutting trajectory.

[0076] Please refer to Figure 3 Step S13 includes:

[0077] Step S131: Determine the maximum distance between the contour points of the first processing cycle and the corresponding multiple contour points of the previous adjacent processing cycle.

[0078] Step S132: Calculate the distortion correction degree of the contour points in the first processing cycle by using the maximum distance difference between adjacent contour points in the first processing cycle and the degree of contour distortion.

[0079] Step S133: Calculate the distortion deviation of the contour points on the first processing cycle using the degree of contour distortion and the degree of distortion correction of the contour points on the first processing cycle.

[0080] In this embodiment, the processing contours of adjacent processing rounds j-1 and j (j being the first processing round, referring to any processing round at the beginning of processing, and j-1 being the preceding adjacent processing round) are compared using the DTW (Dynamic Time Warping) algorithm. Multiple contour points of the contour points on processing round j are obtained on processing round j-1.

[0081] The Euclidean distance formula is used to calculate the distance between a contour point k (any contour point) on machining circle j and multiple corresponding points on machining circle j-1. The maximum distance is obtained by comparison. .

[0082] Calculate the maximum distance between adjacent contour points k-1 and k on the processing circle j. The maximum distance difference between them .

[0083] when( The smaller the value, the less distortion of the contour obtained when cutting to the contour point k of the machining circle j. The larger the value, the less the cutting allowance changes at this point in the command's cutting trajectory, and the less the distortion of the contour is affected by the command's cutting contour arrangement. The greater the degree of distortion of the contour at the current position.

[0084] This allows us to determine the degree of distortion correction of the contour when cutting to the contour point k after machining revolution j. In the formula, This represents the maximum distance difference. The value exp represents the degree of contour distortion, and exp represents an exponential function with the natural constant as the base.

[0085] Using the maximum-minimum normalization method After normalization, we get Its range is [-0.5, 0.5]. It should be noted that the normalization interval is generally [0, 1]. In order to set the range to [-0.5, 0.5], it can be achieved through a simple linear transformation, that is, subtracting 0.5 from [0, 1].

[0086] when The larger the value, the greater the distortion of the contour should be. Therefore, the degree of distortion deviation at contour point k when cutting to the machining circle number j can be obtained. ; Indicates the degree of contour distortion. This indicates the degree of distortion correction after normalization.

[0087] The distortion deviation at different cutting contour positions (contour points) was calculated using the above implementation process. The maximum-minimum normalization method was then used to... After normalization, we get Its range is [0,1]. When When the value is greater than 0.5 (preset distortion threshold, which can be adjusted), the corresponding contour position in the next loop is adjusted.

[0088] Step S2: If the distortion deviation is greater than the preset distortion threshold, determine the reference point corresponding to the position point of the cutting trajectory of the next machining cycle command in the first machining cycle.

[0089] Specifically, step S2 includes:

[0090] If the distortion deviation is greater than the preset distortion threshold, determine multiple contour points corresponding to the position points of the cutting trajectory of the next machining cycle command in the first machining cycle.

[0091] The contour point with the largest distortion deviation among multiple contour points is used as the reference point corresponding to the position point of the cutting trajectory of the next machining cycle command.

[0092] Please refer to Figure 8 , Figure 8 This is a schematic diagram of the displacement direction of the trajectory position point in the high-precision CNC machining method for the annular workpiece of offshore wind turbine rotor house according to the embodiment of the present invention;

[0093] The DTW algorithm is used to compare the original cutting trajectory of the (j+1)th cycle (the next machining cycle after the first machining cycle) with the current cutting trajectory of the jth cycle, resulting in multiple sets of corresponding points. Since the (j+1)th cycle is a smaller machining cycle, a single point on it may have multiple corresponding points in the jth cycle. For the trajectory position point (referred to as "position point," also called a contour point, which can be considered synonymous with contour point) p in the (j+1)th cycle's cutting trajectory, the degree of distortion deviation among the multiple contour points corresponding to it in the jth cycle's cutting trajectory is taken. The largest point is used as the reference point.

[0094] Step S3: Determine the movement vector of the position point using the position point, reference point, and distortion deviation degree; adjust the position point according to the movement vector to obtain the adjusted cutting trajectory of the remaining machining circles.

[0095] To prevent excessive cutting resistance and wear on the workpiece or tool due to severe contour distortion, the cutting contour position in the command should be appropriately modified based on the current contour protrusion to reduce the magnitude of sudden changes in cutting force. Since workpiece contour distortion caused by factors such as workpiece suspension may still occur in later stages of machining, real-time dynamic judgment should be performed during the cutting process to rationally arrange the cutting trajectory in the command.

[0096] Specifically, please refer to Figure 4 Step S3 includes:

[0097] Step S31: Use the direction of the line connecting the position point to the reference point as the direction of movement of the position point in the next processing cycle of the first processing cycle.

[0098] Step S32: Determine the movement vector using the movement direction and the degree of distortion deviation, and adjust the position points according to the movement vector to obtain the adjusted cutting trajectory of the remaining machining revolutions.

[0099] Specifically, step S32, which determines the movement vector using the movement direction and the degree of distortion deviation, includes:

[0100] Using the distortion deviation of the reference point of the first processing cycle and the preset initial distance value, the moving distance of the position point of the next processing cycle is calculated, and the moving direction and moving distance are combined to obtain the moving vector.

[0101] Continue to refer to Figure 8 Based on the above embodiments, in this embodiment, the direction of the line connecting the trajectory position point p to the reference point is taken as the moving direction of the trajectory position point p in the (j+1)th cycle of the command cutting trajectory. In this embodiment of the invention, the direction of movement refers to the direction that the trajectory position point p needs to be adjusted.

[0102] When cutting reaches the contour point k of machining circle j, the degree of distortion deviation at the position of contour point k. When the value is larger, the point corresponding to this position should have a shallower machining depth than the original cutting trajectory in the next machining cycle, and the movement distance in the corresponding direction should be greater.

[0103] Therefore, the distance traveled by point p in the command cutting trajectory when the machining revolution number j+1 can be obtained. (L is the preset initial distance value, which can be set to 0.1mm and is adjustable). Next, when the positions of the contour points in the remaining circles are initially determined to require adjustment of the command cutting trajectory, the moving distance is calculated in this way. Then, combined with the above-mentioned moving direction, the position points are adjusted according to the moving vector to obtain the adjusted command cutting trajectory for the remaining machining circles.

[0104] It is understandable that adjusting the position point according to the movement vector means adjusting the position of the trajectory position point p in the corresponding movement direction and distance.

[0105] Step S4: Determine the difference in distortion deviation of the contour points by using the adjusted cutting trajectory of the adjacent remaining machining cycles, and determine the current movement vector of the contour points of the current number of machining cycles by using the difference in distortion deviation.

[0106] Specifically, please refer to Figure 5 Step S4 includes:

[0107] Step S41: Perform cutting machining using the adjusted command cutting trajectory of each of the adjacent remaining machining cycles, and obtain the contour points of the adjusted command cutting trajectory;

[0108] Step S42: Determine the degree of distortion deviation of each contour point and the difference in the degree of distortion deviation between contour points;

[0109] Step S43: Determine the current movement vector of the current contour point of the current number of turns to be processed by utilizing the difference in the degree of distortion deviation.

[0110] It should be noted that after machining the adjusted cutting paths of adjacent remaining machining cycles, the contour points on the adjusted cutting paths are extracted. Each adjusted cutting path of the remaining machining cycles has contour points.

[0111] Each contour point can be used to calculate the degree of distortion deviation at its position. For two contour points at the same position with different remaining machining cycles, the absolute value of the difference in the degree of distortion deviation can be calculated as the difference in the degree of distortion deviation.

[0112] Specifically, step S43 includes:

[0113] Among the adjacent remaining processing cycles, the remaining processing cycle that is closer to the current processing cycle is taken as the target cycle; the current movement vector of the current processing cycle contour point is determined by using the difference in distortion deviation degree and the distortion deviation degree of the target cycle contour point.

[0114] In this embodiment of the invention, the (m-2)th and (m-1)th cycles are considered as two adjacent remaining processing cycles. Among these two cycles, the remaining processing cycle that is closer to the current processing cycle m is the (m-1)th cycle. Therefore, the (m-1)th cycle is taken as the target cycle.

[0115] In this embodiment, please refer to Figure 9 , Figure 9 This is a schematic diagram of the command cutting trajectory and the actual cutting trajectory in the high-precision CNC machining method for the ring-shaped workpiece of offshore wind turbine rotor house involved in the embodiment of the present invention.

[0116] Even after adjusting the trajectory position points corresponding to a single location, workpiece contour distortion due to factors such as workpiece suspension may still occur in later processing. Therefore, the above implementation process... The adjustment was not accurate enough. Therefore, referring to the feedback after adjusting the trajectory of the adjacent (m-2)th and (m-1)th cycles after the instruction trajectory adjustment (to obtain the actual cutting trajectory), the distance and direction of the instruction cutting trajectory adjustment at the mth cycle (as the current number of cycles to be processed) are obtained according to the above embodiment. It should be noted that the various cycles represented by m here refer to the remaining number of processing cycles after adjusting the instruction cutting trajectory.

[0117] The trajectory points for initial trajectory adjustment are mapped to the trajectories of different revolutions using the above-described process. The distortion deviation of the contour point k position after the command cutting trajectory adjustment is calculated in adjacent revolutions m-1 and m-2. , .

[0118] When the degree of distortion deviation differs The larger, and The greater the distortion deviation of the target circle, the more accurate the adjustment of the trajectory point position in the (m-1)th circle is, and the goal of smoothing the protruding area is not achieved. The adjustment value in the mth circle should be increased.

[0119] This allows us to determine the degree of movement of the contour point k at the m-th lap (excluding the initial adjustment lap). Using the max-min normalization method to... After normalization, we get Its range is [0,1]. When The larger the value, the greater the adjustment distance. Therefore, the current movement distance of the contour point k at the m-th lap can be obtained. The current movement direction is the same as in the above embodiment, thereby obtaining the current movement vector of the contour point of the current number of turns to be processed, and in this way, the positions of multiple contour points of the command cutting trajectory are reasonably adjusted.

[0120] Step S5: Using the current movement vector and the initial cutting rate, obtain the current cutting rate for the current number of machining revolutions.

[0121] To ensure accurate and timely adjustment of contour distortion and to maintain the precision of the ring-shaped workpiece, the cutting rate should be appropriately reduced when the contour distortion is significant, thus ensuring accurate acquisition of relevant data.

[0122] Specifically, please refer to Figure 6 Step S5 includes:

[0123] Step S51: Adjust the number of contour points using the current movement vector and the current number of machining revolutions to determine the degree of reduction in the cutting rate of the current number of machining revolutions;

[0124] Specifically, step S51 includes:

[0125] Determine the proportion of the number of contour points to be adjusted in the current number of processing cycles to the total number of contour points.

[0126] By using the maximum movement vector in the current movement vector and the proportion of the adjustment quantity, the degree of reduction in the cutting rate for the current number of machining revolutions is calculated.

[0127] Step S52: Calculate the current cutting rate for the current number of machining revolutions using the degree of reduction in cutting rate and the initial cutting rate.

[0128] In this embodiment, the percentage of the total number of contour points that underwent position adjustments (the number of contour points adjusted) during the current m-th machining cycle is obtained. .

[0129] Obtain the displacement adjustment of all contour points during the m-th machining cycle, and find the maximum value by comparison. That is, the maximum movement vector in the current movement vector.

[0130] when The larger, and The larger the value, the more severe the contour distortion in the current ring-shaped workpiece, and the more the cutting rate should be reduced.

[0131] Therefore, the degree of reduction in cutting rate during the m-th machining cycle can be obtained. In the formula, norm represents linear normalization. The max-min normalization method is used to... After normalization and subtracting 0.5, we get... Its range is [-0.5, 0.5]. As mentioned above, this range can be handled through a simple linear transformation.

[0132] when The larger the value, the greater the decrease in cutting rate during the m-th machining cycle. Therefore, the current cutting rate during the m-th machining cycle can be obtained. . The cutting rate during the (m-1)th machining cycle can be used as the initial cutting rate.

[0133] Furthermore, the adjustment movement size (movement distance) of different command cutting trajectory position points can be obtained through the above embodiments. Then, the coordinates of the command cutting trajectory position points before and after adjustment can be obtained through system analysis. The coordinate data before and after adjustment can be matched and transmitted to the database for storage.

[0134] The coordinates of different command trajectory positions before and after adjustment were obtained using SQL queries, and then visualized in a table format, as shown in Table 1 below:

[0135]

[0136] This invention makes a preliminary judgment on the degree of deviation of the cutting trajectory based on the changes in cutting force during machining. It eliminates interference from changes in cutting force caused by trajectory settings by considering the cutting allowance when cutting the same position on the commanded trajectory in different revolutions, and corrects the trajectory deviation by considering the influence of morphological changes in the commanded cutting trajectory on the cutting force. It obtains the change in the commanded cutting trajectory for different numbers of cutting revolutions based on the abrupt changes in cutting force. Based on the trajectory deviation performance during machining, the machining rate is reasonably adjusted, making the real-time trajectory adjustment more accurate when machining ring-shaped workpieces, reducing tool wear, and improving the machining accuracy of ring-shaped workpieces for offshore wind turbine rotor houses.

[0137] Example 2:

[0138] This invention also proposes a high-precision CNC machining equipment for ring-shaped workpieces in offshore wind turbine rotor houses. The equipment can be a CNC machine tool, a computer, a server, or a combination of multiple devices.

[0139] like Figure 7 As shown, Figure 7 This is a schematic diagram of the hardware operating environment of a high-precision CNC machining equipment for annular workpieces in offshore wind turbine rotor houses, which is involved in the embodiments of the present invention.

[0140] like Figure 7As shown, the high-precision CNC machining equipment for the ring-shaped workpiece of an offshore wind turbine rotor house may include: a processor 1001, such as a CPU; a network interface 1004; a user interface 1003; a memory 1005; and a communication bus 1002. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display or an input unit such as a control panel; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a WIFI interface). The memory 1005 may be a high-speed RAM memory or a stable, non-volatile memory, such as a disk storage device. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001. The memory 1005, as a computer storage medium, may include a high-precision CNC machining program.

[0141] Those skilled in the art will understand that Figure 7 The hardware structure shown does not constitute a limitation on the device and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0142] Continue to refer to Figure 7 , Figure 7 The memory 1005, which is a computer-readable storage medium, may include an operating system, a user interface module, a network communication module, and a high-precision CNC machining program.

[0143] exist Figure 7 In this embodiment, the network communication module is mainly used to connect to the server and can communicate with the server for data; while the processor 1001 can call the high-precision CNC machining program stored in the memory 1005 and execute the steps in the above embodiments.

[0144] Based on the hardware structure of the high-precision CNC machining equipment for the ring-shaped workpiece of offshore wind turbine rotor house described above, various embodiments of the high-precision CNC machining method for the ring-shaped workpiece of offshore wind turbine rotor house of the present invention are implemented.

[0145] Furthermore, the present invention also provides a computer-readable storage medium. The computer-readable storage medium of the present invention stores a high-precision CNC machining program, wherein, when executed by a processor, the high-precision CNC machining program implements the steps of the high-precision CNC machining method for the ring-shaped workpiece of an offshore wind turbine rotor house as described above.

[0146] The method implemented when the high-precision CNC machining program is executed can be referred to in various embodiments of the high-precision CNC machining method for the ring-shaped workpiece of offshore wind turbine rotor house of the present invention, and will not be repeated here.

[0147] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0148] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0149] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0150] The above description is only a preferred embodiment of the present invention and does not limit the scope of protection of the present invention. All equivalent structural / method transformations made under the inventive concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A high-precision CNC machining method for annular workpieces used in offshore wind turbine rotor houses, characterized in that, The method includes: By using cutting force data and the difference in machining contours between adjacent machining cycles, the degree of distortion deviation of contour points on the first machining cycle is determined; If the distortion deviation is greater than the preset distortion threshold, determine the reference point corresponding to the position point of the cutting trajectory of the next machining cycle command in the first machining cycle; The movement vector of the position point is determined by using the position point, reference point, and degree of distortion deviation. The position point is adjusted according to the movement vector to obtain the adjusted cutting trajectory of the remaining machining circles. The difference in distortion deviation of the contour points is determined by the adjusted cutting trajectory of the adjacent remaining machining cycles, and the current movement vector of the contour point of the current number of machining cycles is determined by the difference in distortion deviation. Using the current movement vector and the initial cutting rate, the current cutting rate for the current number of revolutions to be processed is obtained; The method for determining the degree of distortion deviation of the contour points in the first machining cycle includes: Based on the cutting force time series data, the difference in cutting force between adjacent time moments is determined, and the target cutting force at the target time moment is determined. The degree of contour distortion of the contour points at the target time is calculated using the difference in cutting force and the target cutting force. The degree of distortion deviation of the contour points on the first processing cycle is determined by using the degree of contour distortion of the contour points on the first processing cycle and the difference in processing contours of the adjacent processing cycles.

2. The high-precision CNC machining method for annular workpieces in offshore wind turbine rotor houses according to claim 1, characterized in that, The determination of the distortion deviation degree of the contour point on the first processing cycle by utilizing the degree of contour distortion of the contour point on the first processing cycle and the difference in processing contour of its adjacent processing cycles includes: Determine the maximum distance between the contour points of the first processing cycle and the corresponding contour points of the previous adjacent processing cycle; The distortion correction degree of the contour points in the first processing cycle is calculated by using the maximum distance difference between adjacent contour points in the first processing cycle and the degree of contour distortion. The degree of distortion deviation of the contour points on the first machining cycle is calculated by using the degree of contour distortion and the degree of distortion correction on the first machining cycle.

3. The high-precision CNC machining method for annular workpieces in offshore wind turbine rotor houses according to claim 1, characterized in that, When the distortion deviation exceeds a preset distortion threshold, determining the reference point corresponding to the position point of the cutting trajectory of the next machining cycle command in the first machining cycle includes: If the distortion deviation is greater than the preset distortion threshold, determine multiple contour points corresponding to the position points of the cutting trajectory of the next machining cycle command in the first machining cycle. The contour point with the largest distortion deviation among multiple contour points is used as the reference point corresponding to the position point of the cutting trajectory of the next machining cycle command.

4. The high-precision CNC machining method for annular workpieces in offshore wind turbine rotor houses according to claim 1, characterized in that, The process of determining the movement vector of the position point using the position point, reference point, and distortion deviation degree, and adjusting the position point according to the movement vector to obtain the adjusted cutting trajectory for the remaining machining revolutions includes: The direction of the line connecting the position point to the reference point is used as the direction of movement of the position point in the next processing cycle after the first processing cycle. The movement vector is determined by the direction of movement and the degree of distortion deviation. The position points are adjusted according to the movement vector to obtain the adjusted cutting trajectory of the remaining machining revolutions.

5. The high-precision CNC machining method for annular workpieces in offshore wind turbine rotor houses according to claim 4, characterized in that, The method of determining the movement vector using the direction of movement and the degree of distortion deviation includes: Using the distortion deviation of the reference point of the first processing cycle and the preset initial distance value, the moving distance of the position point of the next processing cycle is calculated, and the moving direction and moving distance are combined to obtain the moving vector.

6. The high-precision CNC machining method for annular workpieces in offshore wind turbine rotor houses according to claim 1, characterized in that, The step of determining the difference in distortion deviation of the contour points using the adjusted cutting trajectory of adjacent remaining machining cycles, and determining the current movement vector of the contour point for the current number of machining cycles using the difference in distortion deviation, includes: The cutting process is performed using the adjusted cutting trajectory of each of the adjacent remaining machining cycles, and the contour points of the adjusted cutting trajectory are obtained. Determine the degree of distortion deviation of each contour point and the difference in the degree of distortion deviation between contour points; The current movement vector of the contour point of the current number of turns to be processed is determined by the difference in the degree of distortion deviation.

7. The high-precision CNC machining method for annular workpieces in offshore wind turbine rotor houses according to claim 6, characterized in that, The method of determining the current movement vector of the current contour point of the current number of cycles to be processed by utilizing the difference in the degree of distortion deviation includes: Among adjacent remaining processing cycles, the remaining processing cycle number that is closer to the current processing cycle number is taken as the target cycle number; By utilizing the differences in distortion deviation and the distortion deviation of the target circle number contour point, the current movement vector of the current circle number contour point to be processed is determined.

8. The high-precision CNC machining method for annular workpieces in offshore wind turbine rotor houses according to claim 1, characterized in that, The step of obtaining the current cutting rate for the current number of machining revolutions using the current movement vector and the initial cutting rate includes: By adjusting the number of contour points based on the current movement vector and the current number of machining revolutions, the degree of reduction in the cutting rate for the current number of machining revolutions is determined. The current cutting rate is calculated by using the degree of reduction in cutting rate and the initial cutting rate to determine the current number of machining revolutions.

9. The high-precision CNC machining method for annular workpieces in offshore wind turbine rotor houses according to claim 8, characterized in that, The step of adjusting the number of contour points based on the current movement vector and the current number of machining revolutions to determine the degree of reduction in the cutting rate for the current number of machining revolutions includes: Determine the proportion of the number of contour points to be adjusted in the current number of processing cycles to the total number of contour points. By using the maximum movement vector in the current movement vector and the proportion of the adjustment quantity, the degree of reduction in the cutting rate for the current number of machining revolutions is calculated.

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