A method for determining a clamping posture in five-axis detection of a bladed disc, a medium and an apparatus

Abstract

The present application relates to the field of precision measurement, in particular to a method for determining the clamping posture in five-axis detection of a blisk, a medium and an apparatus. The method comprises the following steps: obtaining the yaw angle ω and the pitch angle φ of the required probe direction and the measurement boundary direction in the spherical coordinate system for planning the measurement path of the blade to be measured of the blisk, and mapping them to the corresponding pixel points of the global accessibility map (GAM). According to the inclusion of each pixel group of the blade to be measured and the angle constraint curve of the measurement boundary direction in the map, the yaw angle and / or the pitch angle of the blisk clamping are adjusted, and the tilting posture of the blisk when the angle constraint curve contains the most pixel groups is determined as the optimal clamping posture. The method is based on the image data structure of GAM, converts the clamping optimization into an image processing problem, can intuitively present the constraint relationship between the probe direction and the motion boundary, can automatically plan the optimal clamping posture, and can accurately determine the minimum clamping times, and has more advantages than the existing commercial software.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of precision measurement, in particular to a method for determining a clamping posture in five-axis measurement of a blisk, a medium and an apparatus. BACKGROUND

[0002] The geometry of the blisk blade directly affects its aerodynamic performance, so the surface size detection of the blisk is particularly important in the manufacture of an aero-engine. Compared with non-contact optical measurement methods, contact detection represented by coordinate measuring machines has higher measurement accuracy, better robustness for highly reflective surfaces, and is suitable for blisk structures with more serious occlusion. A five-axis scanning measurement system composed of a three-coordinate measuring machine and a double-rotating-axis continuous scanning measuring seat can realize high-speed scanning measurement of complex surfaces. Compared with traditional three-axis scanning measurement, it has faster speed and better obstacle avoidance ability for complex structures, without the need to manually change the posture of the measuring head during measurement.

[0003] Due to the limitation of the mechanical structure of the measuring machine, the measuring head can only reach a limited area in space. For complex curved surface parts such as blisks, when the part is fixed on the workbench of the measuring machine in a certain posture, the measuring head can only scan and measure part of the area of the blade without interference. In order to realize complete measurement of the blade surface, the operator needs to change the posture and measure again after completing the measurement in a certain posture, and repeat the above process until all the blade surfaces of the blisk are completely measured. In actual detection, the posture of the blisk clamped each time is usually determined by the operator according to the spatial structure of the blade through experience. Although this clamping method based on experience is effective for simple workpieces, it is often difficult to obtain the minimum number of clamping times for complex structure parts such as impellers. Since the relationship between the workpiece coordinate system and the measuring machine coordinate system is re-established each time the part is clamped, the measurement error accumulates, and the more the number of clamping times, the more significant the accumulated error.

[0004] Currently, there is no function in existing commercial software that can automatically optimize the clamping posture of the workpiece, and the clamping posture of the part is completely determined by the experience of the operator. This method is feasible for simple structure parts, resulting in low measurement efficiency and large error. Therefore, there is an urgent need for a method that can automatically determine the minimum number of clamping times to solve the problems caused by the experience-based clamping of workpieces in the prior art. SUMMARY

[0005] In view of one of the above technical problems, the technical solution adopted by the present application is:

[0006] According to one aspect of the present application, a method for determining a clamping posture in five-axis measurement of a blisk is provided, the method comprising the following steps:

[0007] The required probe direction and the measurement boundary direction of each blade to be measured in the blade disc correspond to the yaw angle coordinate ω and the pitch angle coordinate φ in the same spherical coordinate system, respectively.

[0008] According to the ω and φ corresponding to each probe direction and the measurement boundary direction, each probe direction and the measurement boundary direction is mapped to the corresponding pixel point in the global reachability map. The global reachability map includes orthogonal pixel U axis and pixel V axis. The angle range corresponding to the pixel U axis is The angle range corresponding to the pixel V axis is [-π, π].

[0009] Each pair of ω and φ and the pixel coordinates [u GAM , v GAM ] of the corresponding pixel point in the global reachability map satisfy the following relationship:

[0010] .

[0011] Wherein, △φ is the distance between any two adjacent pixel points in the global reachability map.

[0012] According to the inclusion relationship between the pixel group corresponding to each blade to be measured and the angle constraint curve corresponding to the measurement boundary direction in the global reachability map, the yaw angle and / or pitch angle of the blade disc clamping is adjusted, and the corresponding blade disc tilt posture when the angle constraint curve contains the largest number of pixel groups is taken as the optimal blade disc clamping posture.

[0013] Further, the blades to be measured in the blade disc are in a central symmetric structure.

[0014] Further, the inclusion relationship between the pixel group corresponding to each blade to be measured and the angle constraint curve corresponding to the measurement boundary direction, adjusting the yaw angle and / or pitch angle of the blade disc clamping, taking the corresponding blade disc tilt posture when the angle constraint curve contains the largest number of pixel groups as the optimal blade disc clamping posture, includes:

[0015] After adjusting the yaw angle and / or pitch angle of the blade disc clamping each time, the new probe direction required for planning the measurement path of each blade to be measured is determined again.

[0016] According to the new probe direction, a new pixel group corresponding to each blade to be measured is generated in the global reachability map.

[0017] According to the inclusion relationship between the new pixel group and the angle constraint curve corresponding to the measurement boundary direction, it is determined that the number of new pixel groups contained in the angle constraint curve after adjusting the angle of the blade disc clamping.

[0018] According to the number of new pixel groups contained in the angle constraint curve after each adjustment of the blade clamping angle, the optimal blade clamping posture is determined.

[0019] Further, the original angle constraint curve corresponding to the boundary direction of measurement is a straight line of φ=φ lim , and φ lim is the pitch angle direction of the measuring head.

[0020] According to the inclusion between the pixel group corresponding to each to-be-measured blade in the global reachability map and the angle constraint curve corresponding to the boundary direction of measurement, the yaw angle and / or the pitch angle of the blade clamping is adjusted, and the corresponding blade tilt posture when the angle constraint curve contains the largest number of pixel groups is taken as the optimal blade clamping posture, comprising:

[0021] After each adjustment of the pitch angle of the blade clamping, the corresponding new angle constraint curve of the boundary direction of measurement in the global reachability map is determined again according to the adjusted pitch angle θ. The new angle constraint curve φ'(ω) satisfies the following conditions:

[0022] .

[0023] According to the number of new pixel groups contained in the angle constraint curve after each adjustment of the blade clamping angle, the optimal blade clamping posture is determined.

[0024] Further, the method further comprises:

[0025] According to the number n x of pixel groups contained in the angle constraint curve under the optimal blade tilt posture, and the total number n b of to-be-measured blades included in the blade, the clamping times P of the blade in a complete five-axis detection is generated. P satisfies the following condition: P=roundup(n b / n x ).

[0026] Further, the method further comprises: according to the number of new pixel groups contained in the angle constraint curve after each adjustment of the blade clamping angle, the optimal blade clamping posture is determined, comprising:

[0027] Using binary search, iterative search is performed in the initial pitch adjustment angle range [θ low , θ high ]; θ low is the pitch angle 0°, and θ high is the maximum pitch angle of the blade clamp.

[0028] In each iteration, the number of pixel groups contained in the angle constraint curve and the distance from the contained pixel groups to the angle constraint curve are taken as the corresponding angle evaluation value.

[0029] Furthermore, obtain the probe directions and probe measurement boundary directions required for the planned measurement path for all blades to be measured in the bladed disk, and their corresponding yaw angle coordinates ω and pitch angle coordinates φ in the same spherical coordinate system, including:

[0030] The probe directions and measurement boundary directions required for the planned measurement paths of all blades to be measured are mapped to the same spherical coordinate system. The origin of the spherical coordinate system is located at the joint center of the probe, and the X, Y, and Z axes of the spherical coordinate system are consistent with the XYZ axes in the MCS of the five-axis scanning measurement system. The spherical coordinate system includes two orthogonal axes: yaw and pitch. The unit direction vector V corresponding to any probe direction or measurement boundary direction in the MCS is... M In a spherical coordinate system, the corresponding yaw angle coordinates ω and pitch angle coordinates φ satisfy the following conditions:

[0031] .

[0032] Among them, V M x V M y and V M z V M Projected lengths in the X, Y, and Z axis directions.

[0033] Furthermore, before mapping the probe directions and probe measurement boundary directions required for the planned measurement paths corresponding to all the blades to be measured to the same spherical coordinate system, the method also includes:

[0034] In the part coordinate system, obtain the first unit direction vector V corresponding to the probe direction required for the planned measurement path of all blades to be measured. P .

[0035] V P Transformed into the MCS of a five-axis scanning measurement system to form V P The corresponding second unit direction vector V M The following conditions must be met:

[0036] .

[0037] Among them, R M P This is the rotation transformation matrix from the part coordinate system to the MCS.

[0038] According to a second aspect of the present invention, a non-transitory computer-readable storage medium is provided, which stores a computer program that, when executed by a processor, implements the above-described method for determining the clamping posture in a five-axis impeller detection.

[0039] According to a third aspect of the present application, there is provided an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor implementing the above-mentioned method for determining clamping posture in five-axis measurement of a bladed disk when executing the computer program.

[0040] The present application has at least one of the following beneficial effects:

[0041] The present application proposes a data structure based on images, called global accessibility map (GAM). By mapping the probe direction required for planning the measurement path of the blade to be measured and the measurement boundary direction of the probe to the same image area, i.e., GAM, the relationship between the probe direction required for part measurement and the boundary constraint of probe movement can be intuitively represented. Further, the clamping optimization problem is formulated as an image processing problem, and the optimal bladed disk clamping posture can be determined according to the number of pixel groups contained in the angle constraint curve under different clamping postures in the image, so that as many blades as possible can be measured at a single time under the optimal bladed disk clamping posture, so as to accurately solve the minimum clamping times. Compared with existing commercial software, this method can automatically plan the optimal clamping posture and more accurately determine the minimum clamping times. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0043] Figure 1 A flowchart of a method for determining clamping posture in five-axis measurement of a bladed disk is provided for the embodiments of the present application.

[0044] Figure 2 A structural schematic diagram of a spherical coordinate system is provided for the embodiments of the present application.

[0045] Figure 3 GAM schematic diagrams under different conditions are provided for the embodiments of the present application. (a) is the original GAM, (b) is the GAM when the workpiece is tilted by 45 degrees around the y-axis, and (c) is the GAM when the probe is tilted by -45 degrees.

[0046] Figure 4 A result schematic diagram of the bladed disk after adjusting the direction in the process of finding the optimal clamping posture is provided for the embodiments of the present application. DETAILED DESCRIPTION

[0047] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0048] As a possible embodiment of the present application, as shown in Figure 1 , a method for determining the clamping posture in five-axis detection of a blisk is provided, and the method comprises the following steps:

[0049] S100: Obtain the required probe direction and the measurement boundary direction of the probe corresponding to the planned measurement path of all the blades to be measured in the blisk, and the corresponding yaw angle coordinate ω and the pitch angle coordinate φ in the same spherical coordinate system.

[0050] In the embodiment, the five-axis scanning measurement system can be a five-axis coordinate measuring machine or a five-axis machine tool. Specifically, the five axes of the scanning measurement system specifically include three linear axes XYZ and two rotary axes of the pitch and yaw of the probe head. The probe is installed on the probe head and is adjusted by the five-axis drive to obtain the surface shape information of different positions of the blade to be measured. The blisk is clamped on the corresponding blisk clamp, which can drive the blisk to rotate around its center axis (rotate around the Z axis in Figure 4 to adjust the yaw angle), and can also drive the blisk to pitch (rotate around the Y axis in Figure 4 to adjust the pitch angle).

[0051] In addition, in order to facilitate the representation of the direction vector, three coordinate systems are involved in the embodiment, one is the machine coordinate system MCS of the five-axis scanning measurement system, one is the part (blisk) coordinate system PCS, and the other is the spherical coordinate system, as shown in Figure 2 , wherein the origin of the spherical coordinate system is located at the joint center of the probe head, and the X axis, Y axis and Z axis of the spherical coordinate system are consistent with the XYZ three-axis direction in the MCS. The spherical coordinate system includes two orthogonal axes of yaw and pitch, and the direction vector in space is represented by the yaw angle and the pitch angle.

[0052] Specifically, S100 comprises:

[0053] S101: In the part coordinate system (PCS), obtain the first unit direction vector V P corresponding to the required probe direction of the planned measurement path of all the blades to be measured.

[0054] In this step, in order to facilitate planning calculation, a five-axis linkage swing scan path planning method can be used to plan the measurement paths corresponding to all the to-be-measured blades in the PCS, and then the required probe direction for planning the measurement paths in the PCS can be obtained, and then the V P .

[0055] S102: Convert V P into the MCS of the five-axis scanning measurement system to form V P the corresponding second unit direction vector V M . The following conditions are met:

[0056] .

[0057] wherein R M P is the rotation transformation matrix from the part coordinate system to the MCS.

[0058] Since the probe is controlled and moved in the MCS, it is necessary to convert V P into the MCS to form V P the corresponding second unit direction vector V M . Since V P and V M are unit direction vectors, the conversion can be completed only by R M P .

[0059] S103: Map the required probe direction and the measurement boundary direction of the probe of the planning measurement path corresponding to all the to-be-measured blades into the same spherical coordinate system.

[0060] The unit direction vector V M corresponding to any probe direction or measurement boundary direction in the MCS, the corresponding yaw angle coordinate ω and the pitch angle coordinate φ in the spherical coordinate system, meet the following conditions:

[0061] .

[0062] wherein V M x , V M y and V M z are the projection lengths of V M in the X-axis, Y-axis and Z-axis directions.

[0063] In S103, the required probe direction and the measurement boundary direction of the probe of the planning measurement path are mapped into the same spherical coordinate system and are represented by ω and φ respectively, which lays a foundation for subsequent conversion of these direction vectors into the same graphical domain for representation.

[0064] S200: mapping each probe direction and measurement boundary direction to a corresponding pixel point in the global accessibility map according to the corresponding ω and φ of each probe direction and measurement boundary direction. The global accessibility map includes orthogonal pixel U-axis and pixel V-axis. The angle range corresponding to the pixel U-axis is [0, π]. The angle range corresponding to the pixel V-axis is [-π, π].

[0065] Each pair of ω and φ, and the pixel coordinates [u GAM , v GAM ] of the corresponding pixel point in the global accessibility map satisfy the following relationship:

[0066] .

[0067] Wherein, △φ is the distance between any two adjacent pixel points in the global accessibility map.

[0068] The construction method of GAM is to map the directions of the entire region to a rectangular image domain (GAM), and further discretize it into n ω ×n φ pixels, that is, the resolution is n ω ×n φ . The specific resolution size can be controlled according to the required discretization accuracy (that is, △φ) and the calculation consumption. The rectangular image domain includes orthogonal pixel U-axis and pixel V-axis. The pixel U-axis corresponds to the pitch angle, and the angle range is . The pixel V-axis corresponds to the yaw angle, and the angle range is [-π, π]. Each probe direction corresponding to the probe path can be represented as a pixel in the GAM, and the measurement boundary direction of the probe can be represented as a boundary range in the GAM.

[0069] Generally, since the probe head can rotate 360° in the yaw angle direction, when considering the measurement boundary, the restriction of the yaw angle direction can not be considered.

[0070] In addition, in the pitch angle direction, the rotation range of the probe is generally not a full 180 degrees. Usually, the probe can reach an angle of -π / 2 in the pitch direction, but the pitch angle will be different. Since -π / 2 is the lower limit of the GAM domain, the pixel will not exceed this range, so generally the lower limit of the pitch direction is not needed. For example, if the rotation angle of the probe in the pitch axis is 120°, that is, the corresponding pitch angle range is [-90°, 30°]. Since φ=-90°, the probe is in a singular position, and the φ angle cannot be further reduced. No matter which direction the probe rotates, the corresponding φ angle will increase. Therefore, the probe constraint only restricts the upper limit and cannot restrict the lower limit. That is, when φ=-90°, the object can be measured, and as long as the object is rotated and the corresponding φ angle does not exceed 30°, it can be measured because the φ angle will not further decrease to less than -90°. Therefore, in the GAM, when mapping the measurement boundary direction, only the curve corresponding to the upper limit measurement boundary direction of the pitch angle of the probe needs to be considered. The curve corresponding to the upper limit measurement boundary direction and the left and right boundaries in the GAM are the combined areas, that is, the reachable area of the probe. That is, the measurement direction corresponding to the pixel points in this area is feasible. For example, as shown in (b) and (c) in FIG. 6, the pixel groups are all located in the range drawn by the angle constraint curve; otherwise, it is not feasible, as shown in (a) in FIG. 6, the pixel groups all intersect with the range drawn by the angle constraint curve. Figure 3 Figure 3

[0071] S300: According to the inclusion relationship between each pixel group corresponding to a to-be-measured blade in the global reachability map and the angle constraint curve corresponding to the measurement boundary direction, adjust the yaw angle and / or the pitch angle of the blade disc clamping, and take the corresponding blade disc tilt posture when the angle constraint curve contains the largest number of pixel groups as the optimal blade disc clamping posture.

[0072] By continuously adjusting the clamping posture of the blade disc, more pixel groups in the GAM can be brought into the boundary range to determine the maximum number of blades that can be measured at a time. In this embodiment, the pixel group is the set of pixel points corresponding to the measurement needle direction when measuring a complete blade. Because blade parameter evaluation is usually performed on a complete blade as the minimum unit, if the measurement results of the same blade are obtained using two different clamping angles, positioning errors will be introduced, which will make the parameter evaluation inaccurate.

[0073] Therefore, in S300, when determining the optimal blade disc clamping posture, the complete pixel group needs to be included in the angle constraint curve to avoid the situation that the pixel group intersects with the angle constraint curve. By determining multiple optimal blade disc clamping postures, the measurement needle directions of all to-be-detected blades are included to realize the measurement of all to-be-detected blades.

[0074] ​​Typically, the blades to be measured in a bladed disk have a centrally symmetrical structure. Special attention needs to be paid to the original angle constraint curve corresponding to the measurement boundary direction of the upper limit of pitch, which is φ=φ. lim The straight line, φ lim This defines the measurement boundary in the pitch direction of the probe. For example, if the probe's pitch axis rotates at an angle of 120°, then the angle constraint curve to be drawn in GAM is φ=φ lim A horizontal straight line at a angle of 30°, such as Figure 3 As shown in (a) in the figure. The horizontal straight line with φ=30°, together with the left, right and lower boundaries of GAM, forms the reachable area of ​​the probe.

[0075] According to the formation principle of GAM, this GAM has two basic characteristics:

[0076] I. The rotation of the workpiece around the Z-axis can be represented by the horizontal movement of pixels along the V-axis. Furthermore, the first column (ω=-π) and the last column (ω=π) of the GAM are in the same position in actual space; therefore, a cyclic shift operation is required during horizontal movement. The attitude adjustment of the workpiece (bladed disk) in the yaw angle direction conforms to attribute I.

[0077] II. The tilt of the workpiece around the Y-axis can be represented in GAM as the result of the combined movement of pixels along the U-axis and V-axis. The attitude adjustment of the workpiece (impeller) in the pitch direction conforms to attribute II.

[0078] For example, when the workpiece is tilted 45 degrees around the Y-axis, according to attribute II, the pixel group will... Figure 3 (a) in the middle is converted to Figure 3 The location is shown in (b) above. In this case, all colored pixels are below the red line, meaning the entire scan path is fully accessible.

[0079] Therefore, after each adjustment of the bladed disk's clamping posture, the optimal bladed disk clamping posture can be determined by the positional relationship between the newly obtained pixel group and the original angle constraint curve.

[0080] In this case, S300 includes:

[0081] S301: After each adjustment of the yaw angle and / or pitch angle of the blade disk clamping, the new probe direction required for the planned measurement path of each blade to be measured is re-determined.

[0082] S302: Based on the new probe direction, generate a new pixel group corresponding to each blade to be measured in the global reachability map.

[0083] S303: Determine the number of new pixel groups contained in the angle constraint curve after adjusting the blade clamping angle according to the inclusion between the new pixel groups and the angle constraint curve corresponding to the measurement boundary direction.

[0084] S304: Determine the optimal blade clamping pose according to the number of new pixel groups contained in the angle constraint curve after adjusting the blade clamping angle each time.

[0085] In this embodiment, the current clamping pose is determined by recalculating the position of the pixel group after adjusting the pose each time.

[0086] In the above embodiment, although the positional relationship between the adjusted pixel group and the angle constraint curve can be determined, the calculation amount is large. In the following embodiment, a S300 implementation step with smaller calculation amount is provided:

[0087] S310: According to the inclusion between the pixel group corresponding to each to-be-measured blade in the global reachability map and the angle constraint curve corresponding to the measurement boundary direction, adjust the yaw angle and / or pitch angle of the blade disk clamping, and take the corresponding blade disk tilt pose when the angle constraint curve contains the maximum number of pixel groups as the optimal blade disk clamping pose, comprising:

[0088] S320: After adjusting the pitch angle of the blade disk clamping each time, determine the corresponding new angle constraint curve of the measurement boundary direction in the global reachability map according to the adjusted pitch angle θ. The new angle constraint curve φ'(ω) satisfies the following conditions:

[0089] .

[0090] Specifically, the angle constraint curve is φ=φ lim The direction vector K of the measuring needle on the angle constraint curve can be expressed as:

[0091] ;

[0092] When the workpiece is tilted by an angle θ around the y-axis, the original direction vector K is converted to K', ;

[0093] Since From the above formula, we can know Correspondingly, the new angle constraint curve .

[0094] S330: Determine the optimal blade clamping pose according to the number of pixel groups contained in the new angle constraint curve after adjusting the blade clamping angle each time.

[0095] Considering the relativity of the motion between the workpiece and the measuring head, i.e., tilting the part by φs The degree is equivalent to tilting the probe by -φ s Therefore, it is only necessary to transform the pixels of the angle constraint curve to the new position, such as... Figure 3 As shown in (c), the positional relationship between the adjusted pixel group and the angle constraint curve can be determined. Figure 3 (b) and Figure 3 The reachability shown in (c) is exactly the same. Therefore, by transforming the angle constraint lines instead of all direction-dependent pixels, the computational cost will be significantly reduced.

[0096] The S330 includes:

[0097] S331: Use binary search to adjust the initial angle range [θ] in pitch adjustment. low θ high Perform an iterative search. θ low With a pitch angle of 0°, θ high This is the maximum pitch angle of the bladed disk clamp. Typically, the upper limit is θ. high Determined based on the working range of the selected fixture, generally θ high =60°.

[0098] In each iteration, the number of pixel groups contained in the angle constraint curve and the distance of the contained pixel groups from the angle constraint curve are used as the corresponding angle evaluation value.

[0099] The amplitude of the angle constraint curve on the GAM can be changed by adjusting the workpiece's tilt angle around the Y-axis. The larger the absolute value of the tilt angle, the more prominent the angle constraint curve is in the middle and the more it dips at both ends. A significant bulge in the middle of the curve helps to include more pixel groups and move them away from the curve, while the dip at the ends has the opposite effect. Therefore, there must be a clamping angle that corresponds to the angle constraint curve containing the most pixel groups. Pixel groups below the curve are called qualified pixel groups because these pixels can be accessed through a specified machine configuration. If multiple clamping angles contain the same number of pixel groups, the clamping angle with the largest distance between its qualified pixel groups and the angle constraint curve is selected. The angle obtained in this way is called the optimal tilt angle.

[0100] Specifically, based on the above analysis of obtaining the optimal tilt angle, it is clear that binary search is suitable for this situation to narrow the search range. Therefore, as shown in S331, in each iteration, the search interval for the angle is divided into two parts, with the lower limit denoted as β. low The upper limit is denoted as β high The midpoint is denoted as β mid Then, calculate the number of pixel groups that meet the conditions, i.e., N. L N h N m And the distance from the qualifying pixel group to the curve, i.e., D.L , D h , D m , corresponding to the tilt angle β low , β high , β mid . By comparing the size of N L , N h , N m , we can determine the following three scenarios:

[0101] N L >N m : the optimal angle can be found in [β low , β mid ].

[0102] N m <N h : the optimal angle can be found in [β mid , β high ].

[0103] N m ≥N L and N m ≥N h : search for the best angle in the range of [β low , β mid ] and [β mid , β high ], compare the results of the two intervals.

[0104] This iterative search process can be implemented recursively. It continues until β low is adjacent to β high , that is, when β low =β high -1. At this time, the optimal angle in the interval can be directly determined by comparing N and D, and it should be noted that the workpiece is allowed to rotate around the Z axis. Therefore, in each iteration, the optimal movement of the pixel group along the V axis in the GAM can also be determined according to the minimum distance between the pixel group and the angle constraint curve.

[0105] Further, the method further comprises:

[0106] S400: generating the clamping times P of the leaf disc in a complete five-axis detection according to the number n x of pixel groups contained in the angle constraint curve at the optimal leaf disc tilt posture, and the total number n b of the measured blades included in the leaf disc. P satisfies the following condition: P = round up (n b / n x ).

[0107] In actual detection, considering that the impeller is a central symmetric component, the scanning path of each blade can be generated and mapped to the GAM as a series of pixels. The scanning path of each blade is generated at the leading edge, the trailing edge, the suction surface and the pressure surface, respectively. Therefore, the pixels corresponding to the probe direction of the scanning path in a single blade are usually composed of four parts. The four pixel areas corresponding to a single blade are represented by the same color in the GAM and named as a pixel group, as shown in Figure 4 .

[0108] Minimizing the number of clamping pose settings of the blisk is equivalent to adjusting the tilt angle of the workpiece around the Y axis to include as many pixel groups as possible. Then the inaccessible blades under this tilt angle are measured by rotating the workpiece around the Z axis. The whole process is shown in Figure 4 . Assuming that one adjustment of the tilt angle can include n x pixel groups, i.e. n x blades of the corresponding blisk are accessible, a total of P times is required to completely measure the entire impeller.

[0109] In addition, although the various steps of the method in the present disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. In addition or alternatively, certain steps can be omitted, multiple steps can be combined into one step, and / or one step can be divided into multiple steps, etc.

[0110] From the above description of the embodiments, those skilled in the art can easily understand that the example embodiments described herein can be implemented by software, or by software in combination with necessary hardware. Therefore, the technical solutions according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a U disk, a mobile hard disk, etc.) or a network, and includes a number of instructions to make a computing device (which can be a personal computer, a server, a mobile terminal, or a network device, etc.) execute the methods according to the embodiments of the present disclosure.

[0111] In the example embodiments of the present disclosure, an electronic device capable of implementing the above method is also provided.

[0112] Those skilled in the art can understand that each aspect of the present disclosure can be implemented as a system, a method or a program product. Therefore, each aspect of the present disclosure can be embodied in the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, microcode, etc.), or an embodiment combining hardware and software aspects, which can be collectively referred to as "circuitry", "module" or "system".

[0113] The electronic device according to this embodiment of the present application. The electronic device is merely an example and should not bring any limitation to the function and use range of the embodiments of the present application.

[0114] The electronic device is in the form of a general computing device. The components of the electronic device can include, but are not limited to, the at least one processor described above, the at least one memory described above, and a bus that connects different system components, including the memory and the processor.

[0115] The memory stores program codes that can be executed by the processor, so that the processor performs the steps described in the above "Exemplary Method" section according to various exemplary embodiments of the present application.

[0116] The memory can include a readable medium in the form of a volatile memory, such as a random access memory (RAM) and / or a cache memory, and can further include a read-only memory (ROM).

[0117] The memory can also include programs / utilities with a set of (at least one) program modules, such as an operating system, one or more application programs, other program modules, and program data, each of which or some combination of which can include the implementation of a network environment.

[0118] The bus can be one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor or a local bus using any of a variety of bus structures.

[0119] The electronic device can also communicate with one or more external devices (such as a keyboard, a pointing device, a Bluetooth device, etc.) and can also communicate with one or more devices that enable a user to interact with the electronic device, and / or with any devices (such as a router, a modem, etc.) that enable the electronic device to communicate with one or more other computing devices. Such communication can be carried out through an input / output (I / O) interface. In addition, the electronic device can also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter. The network adapter communicates with other modules of the electronic device through the bus. It should be understood that although not shown in the figure, other hardware and / or software modules can be used in conjunction with the electronic device, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, etc.

[0120] Those skilled in the art can clearly understand, through the description of the above embodiments, that the example embodiments described herein can be implemented by software, or by software in combination with necessary hardware. Therefore, the technical solutions according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a U disk, a mobile hard disk, etc.) or a network, and includes a plurality of instructions to enable a computing device (which can be a personal computer, a server, a terminal device, or a network device, etc.) to perform the method according to the embodiments of the present disclosure.

[0121] In the example embodiments of the present disclosure, a computer readable storage medium is also provided, which stores a program product capable of implementing the above-mentioned method of the present disclosure. In some possible embodiments, various aspects of the present disclosure can also be implemented in the form of a program product, which includes program code for causing a terminal device to perform the steps according to various example embodiments of the present disclosure described in the above-mentioned “example method” section of the present disclosure when the program product is run on the terminal device.

[0122] The program product can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium may, for example, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or component, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0123] The computer readable signal medium can include a data signal propagated in a baseband or as a part of a carrier wave, in which readable program code is borne. Such a propagated data signal can take on multiple forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. The readable signal medium can also be any readable medium other than the readable storage medium, which can send, propagate or transmit the program for use by or in connection with an instruction execution system, device or component.

[0124] The program code contained on the readable medium can be transmitted by any suitable medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination of the above.

[0125] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0126] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0127] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0128] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for determining the clamping posture in five-axis detection of a bladed disk, characterized in that, The method comprises the following steps: Obtaining the required probe direction and the measurement boundary direction of the probe of the planned measurement path of all the to-be-measured blades in the blade disc, and corresponding yaw angle coordinates ω and pitch angle coordinates φ in the same spherical coordinate system; Based on ω and φ corresponding to each probe direction and measurement boundary direction, respectively, each probe direction and measurement boundary direction are mapped to the corresponding pixel in the global reachability map; wherein, the global reachability map includes orthogonal pixel U-axis and pixel V-axis; the angle range corresponding to the pixel U-axis is [missing information]. The angle range corresponding to the V-axis of the pixel is [-π, π]. Each pair of ω and φ, with the pixel coordinates [u GAM , v GAM ] of the corresponding pixel point in the global reachability map, satisfies the following relationship: ； Wherein, △φ is the distance between any two adjacent pixel points in the global reachability map; According to the inclusion condition between the pixel group corresponding to each to-be-measured blade and the angle constraint curve corresponding to the measurement boundary direction in the global reachability map, the yaw angle and / or the pitch angle of the blade disc clamping is adjusted, and the corresponding blade disc tilting posture when the angle constraint curve contains the largest number of pixel groups is taken as the optimal blade disc clamping posture.

2. The method of claim 1, wherein, The to-be-measured blades in the blade disc are in a central symmetric structure.

3. The method of claim 2, wherein, According to the inclusion condition between the pixel group corresponding to each to-be-measured blade and the angle constraint curve corresponding to the measurement boundary direction in the global reachability map, the yaw angle and / or the pitch angle of the blade disc clamping is adjusted, and the corresponding blade disc tilting posture when the angle constraint curve contains the largest number of pixel groups is taken as the optimal blade disc clamping posture, comprising: After adjusting the yaw angle and / or the pitch angle of the blade disc clamping each time, the new probe direction required by the planned measurement path of each to-be-measured blade is re-determined; According to the new probe direction, a new pixel group corresponding to each to-be-measured blade is generated in the global reachability map; According to the inclusion condition between the new pixel group and the angle constraint curve corresponding to the measurement boundary direction, the number of new pixel groups contained in the angle constraint curve after adjusting the blade disc clamping angle is determined; According to the number of new pixel groups contained in the angle constraint curve after adjusting the blade disc clamping angle each time, the optimal blade disc clamping posture is determined.

4. The method of claim 2, wherein, The original angle constraint curve corresponding to the boundary direction of measurement is a straight line of φ = φ lim , and φ lim is the measurement boundary in the pitch angle direction of the probe. According to the inclusion condition between the pixel group corresponding to each to-be-measured blade and the angle constraint curve corresponding to the measurement boundary direction in the global reachability map, the yaw angle and / or the pitch angle of the blade disc clamping is adjusted, and the corresponding blade disc tilting posture when the angle constraint curve contains the largest number of pixel groups is taken as the optimal blade disc clamping posture, comprising: After adjusting the pitch angle of the blade disc clamping each time, according to the adjusted pitch angle θ, the corresponding new angle constraint curve of the measurement boundary direction in the global reachability map is re-determined; the new angle constraint curve φ'(ω) satisfies the following conditions: ； According to the number of pixel groups contained in the new angle constraint curve after adjusting the blade disc clamping angle each time, the optimal blade disc clamping posture is determined.

5. The method according to claim 3 or 4, characterized in that, The method further comprises: According to the number n of pixel groups contained in the angle constraint curve at the optimal blade disc tilt posture x , and the total number n of blades to be measured included in the blade disc b , the clamping times P of the blade disc in one complete five-axis detection are generated; P satisfies the following conditions: P = round up (n b / n x ).

6. The method of claim 4, wherein, The method further comprises: according to the number of pixel groups contained in the new angle constraint curve after adjusting the blade disc clamping angle each time, the optimal blade disc clamping posture is determined, comprising: Using a binary search, an iterative search is performed over a range of initial pitch adjustment angles [θ low , θ high ]; θ low is the pitch angle of 0° and θ high is the maximum pitch angle of the blade fixture; In each iteration, the number of pixel groups contained in the angle constraint curve and the distance from the contained pixel groups to the angle constraint curve are taken as the corresponding angle evaluation value.

7. The method of claim 4, wherein, Obtaining the required probe direction and the measurement boundary direction of the probe of the planned measurement path of all the to-be-measured blades in the blade disc, and corresponding yaw angle coordinates ω and pitch angle coordinates φ in the same spherical coordinate system, comprising: Mapping the probe direction and the measurement boundary direction of all the corresponding planned measurement paths of the blades to be measured to the same spherical coordinate system; the origin of the spherical coordinate system is located at the joint center of the probe head, the X axis, the Y axis and the Z axis of the spherical coordinate system are consistent with the XYZ three-axis direction in the MCS of the five-axis scanning measurement system; the spherical coordinate system includes two orthogonal axes of yaw and pitch; the unit direction vector V M The corresponding yaw angle coordinate ω and the pitch angle coordinate φ in the spherical coordinate system satisfy the following conditions: ； Among them, V M x V M y and V M z V M Projected lengths in the X, Y, and Z axis directions.

8. The method of claim 7, wherein, Before mapping the required probe direction and the measurement boundary direction of each planned measurement path of the to-be-measured blade into the same spherical coordinate system, the method further comprises: In the part coordinate system, obtain the first unit direction vector V corresponding to the direction of the measuring needle required for the planning measurement path corresponding to all the to-be-measured blades P ; V P converted into the MCS of the five-axis scanning measurement system, forming V P a corresponding second unit directional vector V M ; satisfy the following conditions: ； wherein R M P is a rotation transformation matrix from the part coordinate system to the MCS. 9.A non-transitory computer-readable storage medium storing a computer program, the computer program comprising instructions causing a processor to perform the method according to any one of claims 1 to 8. The computer program is executed by the processor to implement the method for determining the clamping posture in the five-axis detection of the blisk according to any one of claims 1 to 8.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the computer program to implement the method for determining the clamping posture in the five-axis detection of the blisk according to any one of claims 1 to 8.

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