Blade non-interference measurement path planning method and system based on non-orthogonal in-machine measurement
By optimizing the measurement path through non-perpendicular measurement and a greedy algorithm, the problems of interference risk and low efficiency in blade measurement of impeller disks were solved, achieving high-precision and high-efficiency measurement results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI TOPNC NUMERICAL CONTROL TECH CO LTD
- Filing Date
- 2026-03-23
- Publication Date
- 2026-05-29
Smart Images
Figure CN122115573A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of complex curved surface detection and sampling technology, and in particular to a method and system for non-interference measurement path planning of blades for bladed disks based on non-perpendicular in-machine measurement. Background Technology
[0002] As a core component in the aerospace industry, the machining accuracy of bladed disks directly determines the power performance, operational stability, and service life of equipment such as aero engines. With the rapid development of digital manufacturing technology, in-machine measurement technology equipped with trigger-type probes has been widely used in the field of bladed disk manufacturing because it can realize online detection during the machining process, identify bladed disk machining errors in real time, and reconstruct the machining surface based on measurement data to optimize subsequent finishing processes, thereby significantly improving the final machining quality.
[0003] However, due to the complex structure of the bladed disk, the large number of blades that overlap and interweave, and the small flow channel space, efficient and interference-free blade measurement path planning has become a core challenge in current in-machine measurement technology applications. To address this challenge, researchers in related fields have conducted extensive research and achieved a series of results: He et al. (He G, Huang X, Ma W, et al. CAD-based measurement planning strategy of complex surface for five axes on machine verification[J]. The International Journal of Advanced Manufacturing Technology, 2017, 91: 2101-2111.) subdivided the surface into discrete grid points and used distance vectors to determine whether there was interference in the detection path; Li et al. (Li W, Wang G, Zhang G, et al. Interference-free inspection path generation for impeller blades using an on-machine probe[J]. IEEE / ASME Transactions on Mechatronics, 2017, 22(3): 1218-1226.) used the reachability cone method to calculate the feasible probe posture for each sampling point on the blade of the impeller disk; in order to minimize the number of probe posture adjustments, Wan et al. (Wan N, Zhuang Q, Guo Y, et al. Multi-Axis On-MachineInspection Path Planning for Free-Form Impeller Based on Least Rotation Times Optimization Model[J]. IEEE Transactions on Instrumentation and Measurement, 2023.) proposes an optimization model for minimizing the number of rotations of the rotating shaft in in-machine measurement of impeller disks, in order to reduce the movement of the rotating shaft, especially the reverse movement; Yi et al. (Yi B, Qiao F, Hua L, et al.)Touch trigger probe-based interference-free inspection path planning for free-form surfaces by optimizing the probe posture[J]. IEEE Transactions on Instrumentation and Measurement, 2022, 71: 1-8.) employs a classification algorithm to divide the detection points into several clusters to reduce the number of probe posture adjustments. For measurement path length optimization, Wan et al. (Wan N, Jiang R, Zhao H, et al. An inspectionpath optimization of impeller for balancing efficiency and accuracy[J]. Measurement, 2019, 141: 472-485.) shorten the measurement path length by keeping the probe within the impeller channel during the inspection process.
[0004] Despite numerous optimizations to existing technologies in on-machine measurement path planning for bladed disks, fundamental limitations remain: current measurement path planning schemes are constrained by vertical measurement, meaning the probe's approach direction must be along the normal to the sampling point. Under this constraint, interference between the probe and the bladed disk can only be avoided by adjusting the probe's attitude. However, due to the complex structure and narrow flow channels of the bladed disk, simply adjusting the probe's attitude is insufficient to completely eliminate interference risks, leading to frequent adjustments. Frequent attitude adjustments inevitably introduce rotation axis positioning errors, affecting measurement accuracy; furthermore, each adjustment requires controlling the probe to move away from the bladed disk to a safe position, significantly increasing measurement time and severely impacting the bladed disk's measurement efficiency.
[0005] Therefore, there is an urgent need to propose a novel measurement path planning method to break through the inherent constraints of vertical measurement, further improve the measurement efficiency and accuracy of bladed disks, and meet the aerospace industry's demand for high-precision and high-efficiency manufacturing and inspection of bladed disks. Summary of the Invention
[0006] To address the problems existing in the prior art, this invention provides a method for non-interference measurement path planning of bladed disks based on non-perpendicular in-machine measurement, comprising: Step S1: Import the three-dimensional model of the blade ... Step S2: Based on all the second probe posture feasible matrices, a greedy algorithm is used to calculate the minimum probe posture required for non-interference measurement of all the sampling points, so as to plan the planned probe posture for each sampling point. Step S3: Based on the planned probe posture of each sampling point, select the approach direction that is farthest from the interference boundary from the first probe posture feasible matrix associated with the sampling point as the planned approach direction of the sampling point; Step S4: The sampling points with the same planned probe posture are grouped into a group, and the measurement sequence of each sampling point in each group is planned to minimize the on-machine measurement path. Then, the sampling points in each group are measured in sequence.
[0007] Preferably, in step S1, the process of obtaining the first probe attitude feasibility matrix under different approach directions by non-perpendicular measurement includes: Step S11: For each approach direction, continuously adjust the posture of the probe, and when the probe approaches the sampling point in the approach direction without colliding with the blade of the impeller in the posture, mark the corresponding posture as a feasible posture. Step S12: Construct the first probe posture feasibility matrix under each of the corresponding feasible postures in each approach direction.
[0008] Preferably, the probe's attitude includes an attitude tilt angle and an attitude rotation angle, the rows and columns of the first probe attitude feasible matrix correspond to the attitude tilt angle and the attitude rotation angle, respectively, and the element values of the first probe attitude feasible matrix indicate whether a collision occurs.
[0009] Preferably, the approach direction includes a directional tilt angle and a directional rotation angle; Before performing step S11, the attitude tilt angle, attitude rotation angle, orientation tilt angle and orientation rotation angle are discretized respectively.
[0010] Preferably, in step S11, the process of determining whether the probe will collide with the blade of the impeller when it approaches the sampling point in the approach direction under the specified posture includes: Based on the three-dimensional model, the blade disk containing the blades is transformed into a triangular surface structure, and the probe is simplified into a ray. The area swept by the probe from the proximity point to the sampling point is simplified into a series of rays. If none of the rays pass through the triangular facet of the bladed disk, it is determined that approaching the sampling point in the approaching direction under the stated posture will not result in a collision with the bladed disk blades.
[0011] Preferably, in step S1, the second probe posture feasible matrix is obtained by performing a dot product operation on all the first probe posture feasible matrices.
[0012] Preferably, step S2 includes: Step S21: Extract the sampling points that can be measured without interference under each probe posture from all the second probe posture feasible matrices and add them to the sampling point set; Step S22: Count the number of sampling points in each of the sampling point sets, and select the probe posture with the most sampling points. If there are multiple probe postures that meet the conditions, select the probe posture that is farthest from the interference boundary. Step S23: Remove the sampling point corresponding to the selected probe posture from each of the sampling point sets; Step S24: Repeat steps S22 to S23 until all sampling points are assigned corresponding probe postures, so as to plan the probe postures for each sampling point.
[0013] Preferably, in step S4, a greedy algorithm is used to plan the measurement sequence of each sampling point in each group so as to minimize the in-machine measurement path.
[0014] Preferably, in step S4, the sequential measurement of each group of sampling points includes: Move the probe to a preset safe position, and perform non-perpendicular on-machine measurements on each sampling point in each group according to the planned measurement sequence, with the planned probe posture and the planned approach direction. After each group of measurements is completed, return to the preset safe position, and then perform the next group of measurements until all sampling points are measured.
[0015] This invention also provides a non-interference measurement path planning system for bladed disks based on non-vertical in-flight measurement. Applying the aforementioned non-interference measurement path planning method for bladed disks, the non-interference measurement path planning system for bladed disks includes: The feasible matrix acquisition module is used to import the three-dimensional model of the blade of the blade, extract the sampling points of the blade of the blade from the three-dimensional model, and for each sampling point, obtain the first probe posture feasible matrix under different approach directions by non-perpendicular measurement, and determine the second probe posture feasible matrix that can be measured without interference under different probe postures and different approach directions based on each first probe posture feasible matrix. The probe posture planning module, connected to the feasible matrix acquisition module, is used to calculate the minimum probe posture required for non-interference measurement of all sampling points based on all the second probe posture feasible matrices using a greedy algorithm, so as to plan the planned probe posture for each sampling point. The proximity direction planning module is connected to the feasible matrix acquisition module and the probe attitude planning module, respectively. It is used to select the proximity direction farthest from the interference boundary from the first probe attitude feasible matrix associated with the sampling point as the planned proximity direction of the sampling point based on the planned probe attitude of each sampling point. The measurement sequence planning module, connected to the probe posture planning module, is used to group the sampling points with the same planned probe posture into a group, and plan the measurement sequence of each sampling point in each group to minimize the on-machine measurement path, and then perform the measurement of each group of sampling points in sequence.
[0016] The above technical solution has the following advantages or beneficial effects: 1) This invention adopts a non-perpendicular measurement strategy, which breaks through the inherent constraint that the approach direction must be along the normal of the sampling point in the existing vertical measurement. The probe can avoid interference and collision by adjusting the approach direction and probe posture, rather than relying solely on adjusting the probe posture. This allows the probe to avoid interference risks more flexibly in the case of complex bladed disk structure and narrow flow channel, indirectly improving the effective measurement capability of narrow and easily interfered areas of bladed disk blades, and solving the problem of difficult measurement of such areas in the existing technology. 2) This invention uses a greedy algorithm to determine the minimum probe posture required for all sampling points in interference-free measurement, and rationally plans the combination of approach direction and probe posture to further reduce the number of probe posture adjustments. The reduction in the number of probe posture adjustments can significantly reduce the positioning error caused by frequent positioning of the machine tool rotating axis, thereby effectively reducing the impact of such errors on the on-machine measurement accuracy, ensuring the accuracy of blade disk blade measurement data, and meeting the needs of high-precision manufacturing and inspection. 3) By dividing sampling points with the same planned probe posture into a group and optimizing the measurement sequence of sampling points within each group, the present invention can significantly shorten the total length of the measurement path, thereby significantly improving the overall efficiency of in-machine measurement of blade disks and solving the problem of excessive measurement time in the prior art. Attached Figure Description
[0017] Figure 1 A flowchart illustrating a method for non-interference measurement path planning of bladed disks based on non-vertical in-machine measurement, as a preferred embodiment of the present invention. Figure 2 A three-dimensional model of the blade of the bladed disc is shown in a preferred embodiment of the present invention. Figure 3 In a preferred embodiment of the present invention, a flowchart illustrating the process of obtaining the first probe posture feasibility matrix under different approach directions by non-perpendicular measurement is provided. Figure 4 A schematic diagram of the first probe posture feasible matrix and the first probe posture feasible matrix in a preferred embodiment of the present invention; Figure 5 This is a schematic diagram of a sub-process of step S2 in a preferred embodiment of the present invention; Figure 6 In a preferred embodiment of the present invention, a schematic diagram is shown in which 36 sampling points on one of the blades of the impeller are divided into two groups and measured in a planned measurement sequence. Figure 7 A schematic diagram of a non-interference measurement path planning system for bladed disks based on non-vertical in-machine measurement is shown in a preferred embodiment of the present invention. Detailed Implementation
[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment; other embodiments that conform to the spirit of the present invention may also fall within the scope of the present invention.
[0019] In a preferred embodiment of the present invention, based on the aforementioned problems existing in the prior art, a non-interference measurement path planning method for bladed disks based on non-perpendicular on-machine measurement is provided. This method aims to overcome the inherent constraints of existing vertical measurement strategies and solve the problems of difficulty in measuring narrow, easily interfering areas of bladed disks, insufficient accuracy due to frequent probe attitude adjustments, and low measurement efficiency by flexibly adjusting the combination of probe approach direction and attitude. Figure 1 As shown, the non-interference measurement path planning method for the blade of this bladed disk includes: Step S1: Import the three-dimensional model of the blade of the blade disk, extract the sampling points of the blade of the blade disk from the three-dimensional model, and for each sampling point, obtain the first probe posture feasible matrix under different approach directions by non-perpendicular measurement, and determine the second probe posture feasible matrix that can be measured without interference under different probe postures and different approach directions based on each first probe posture feasible matrix. Step S2: Based on all the feasible matrices of second probe postures, a greedy algorithm is used to calculate the minimum probe posture required for all sampling points of the non-interference measurement, so as to plan the probe posture for each sampling point. Step S3: Based on the planned probe posture of each sampling point, select the approach direction that is farthest from the interference boundary from the first probe posture feasible matrix associated with the sampling point as the planned approach direction of the sampling point. Step S4: Group the sampling points with the same planned probe posture into a group, and plan the measurement sequence of each sampling point in each group to minimize the on-machine measurement path. Then, measure the sampling points of each group in sequence.
[0020] Specifically, in this embodiment, a three-dimensional model of the blade of the impeller to be measured is first imported. Preferably, based on the three-dimensional model, an existing surface sampling algorithm is used to extract sampling points on the surface of the blade. The number and distribution of sampling points can be flexibly set according to the surface complexity of the blade and the measurement accuracy requirements to ensure that the geometric characteristics of the blade can be fully reflected.
[0021] In a preferred embodiment of the present invention, the probe's attitude includes an attitude tilt angle and an attitude rotation angle, and the approach direction includes a direction tilt angle and a direction rotation angle. For ease of calculation, the attitude tilt angle, attitude rotation angle, direction tilt angle, and direction rotation angle are first discretized. In other words, the attitude tilt angle, attitude rotation angle, direction tilt angle, and direction rotation angle are discretized into several fixed values within their respective ranges. The discretization interval can be set in a balanced manner according to the measurement accuracy requirements and computational efficiency.
[0022] The discretization result can be expressed as:
[0023] In the formula, For the position of the probe, and These are the attitude tilt angle and the attitude rotation angle, respectively. To be closer to the direction, and These are the tilt angle and rotation angle, respectively. It is important to note that the probe's tilt angle and rotation angle are limited by the travel range of the machine tool's rotary axis to avoid invalid postures exceeding the machine tool's operating capabilities.
[0024] For each sampling point, during non-perpendicular measurement, such as Figure 2 As shown, first adjust the probe to an interference-free posture in a safe position and then move it to... The probe is then slowly moved closer to the blade of the impeller in an approaching direction until the ruby ball at the tip of the probe contacts the workpiece. The coordinates of the center of the ruby ball are recorded as the measurement result. Finally, the probe returns. point.
[0025] like Figure 2 As shown, This refers to the position of the center of the ruby sphere when the probe contacts the blade, i.e., the coordinates of the sampling point. It is the closest point, which can be calculated using the following formula:
[0026] in It is the proximity distance (which can be set according to the probe size and impeller structure). It's the direction of proximity.
[0027] For perpendicular measurements, the approach direction is always parallel to the normal vector, and interference can only be avoided by changing the probe posture. For non-perpendicular measurements, interference can be avoided by adjusting the probe posture or the approach direction. Therefore, the probe posture and approach direction for each sampling point need to be planned, specifically including: 1) Construct the first probe attitude feasible matrix In a preferred embodiment of the present invention, in step S1, as follows: Figure 3 As shown, the process of obtaining the first probe attitude feasibility matrix under different approach directions through non-perpendicular measurement includes: Step S11: For each approach direction, continuously adjust the probe's attitude, and mark the corresponding attitude as a feasible attitude when the probe approaches the sampling point in the approach direction without colliding with the blade of the impeller. Step S12: Construct the first probe attitude feasible matrix for each approach direction according to each feasible attitude.
[0028] Specifically, in this embodiment, a certain approach direction is first fixed (i.e., a fixed direction tilt angle is used). and direction rotation angle (discrete values), continuously adjust the probe posture (i.e., change the posture tilt angle) and attitude rotation angle The discrete values are then used to determine the interferometric combination of the approach direction and each probe posture. Subsequently, based on the interferometric determination results, a feasible matrix for the first probe posture under that approach direction is constructed, such as... Figure 4 shown The rows and columns of the first probe attitude feasible matrix correspond to the attitude tilt angle and attitude rotation angle, respectively. The element values of the first probe attitude feasible matrix indicate whether a collision occurs. For example, an element value of 0 indicates that there is no interference in the measurement under the combination of this attitude and the approach direction, while an element value of 1 indicates that interference exists. Taking a certain approach direction... For example, the element values of the corresponding first probe attitude feasibility matrix can be represented as follows:
[0029] Then, by adjusting the approach direction and repeating the above process, multiple feasible matrices of the first probe attitude under different approach directions can be obtained.
[0030] In step S11, the process of determining whether the probe will collide with the blade of the impeller when it approaches the sampling point in an approaching direction under the given attitude includes: Based on the three-dimensional model, the blade disk containing the blades is transformed into a triangular surface structure, and the probe is simplified into rays. The area swept by the probe from the proximity point to the sampling point is simplified into a series of rays. If none of the rays pass through the triangular facet of the bladed disk, it is determined that approaching the sampling point in the approach direction under the given orientation will not result in a collision with the bladed disk blades.
[0031] 2) Generate the second probe attitude feasible matrix by fusing the data. For a given probe posture, if at least one approach direction is feasible, then the probe posture is feasible. Therefore, the second probe posture feasible matrix FMSP is obtained by performing a dot product operation on all the first probe posture feasible matrices. The calculation formula is as follows: .
[0032] Further, in step S2, based on the second probe posture feasibility matrix of all sampling points obtained in step S1, a greedy algorithm is used to determine the minimum probe posture, i.e., to plan the probe posture. Specifically, as follows: Figure 5 As shown, step S2 includes: Step S21: Extract the sampling points that can be measured without interference under each probe posture from all the feasible matrices of second probe postures and add them to the sampling point set; Step S22: Count the number of sampling points in each sampling point set and select the probe posture with the most sampling points. If there are multiple probe postures that meet the conditions, select the probe posture that is farthest from the interference boundary. Step S23: Remove the sampling points corresponding to the selected probe posture from the set of sampling points; Step S24: Repeat steps S22 to S23 until all sampling points are assigned corresponding probe postures, so as to plan the probe postures for each sampling point.
[0033] The minimum probe posture obtained by the greedy algorithm described above can minimize the number of adjustments to the machine tool's rotary axis, thereby reducing the impact of rotary axis positioning error on measurement accuracy. At the same time, it reduces the number of times the probe travels to and from the safe position, improving measurement efficiency.
[0034] Once the planned probe posture for each sampling point is determined, all feasible matrices of the first probe posture corresponding to that sampling point in step S1 are retrieved. From these matrices, the approach directions with an element value of 0 corresponding to the planned probe posture are selected as feasible approach directions. From all feasible approach directions, the approach direction furthest from the interference boundary is chosen as the planned approach direction for that sampling point. This ensures that even if the probe experiences minor posture or positional deviations during measurement, interference is unlikely to occur, further improving the safety and stability of the measurement process.
[0035] Furthermore, step S3 generates the shortest on-machine measurement path by grouping the sampling points and optimizing the measurement order within each group. Specifically, by grouping sampling points with the same planned probe posture into the same group, sampling points within the same group can complete the measurement under the same probe posture without adjusting the probe posture, thus reducing the time spent on posture adjustment when measuring across groups.
[0036] The measurement order of sampling points within a group directly affects the length of the measurement path within the group. Therefore, a greedy algorithm is used to optimize the measurement order within the group, preferably including: Starting from the current probe position (initially a safe position), the nearest sampling point is selected as the next measurement point. After measuring this sampling point, it becomes the new starting point, and the nearest unmeasured sampling point is selected again. This process is iterated until the measurement sequence planning for all sampling points within the group is completed. This optimization method can minimize the measurement path within the group and reduce unnecessary probe movement.
[0037] After a set of sampling points is measured, the probe is moved to a preset safe position, and the probe posture is adjusted to the planned probe posture for the next set of sampling points. Then, the next set of sampling points is measured according to the planned measurement sequence. This process is repeated until all sets of sampling points are measured.
[0038] by Figure 6 Taking 36 sampling points on the surface of the blade as an example, after path planning using the method of this invention, it was determined that two probe postures were needed to measure all sampling points without interference. Therefore, the 36 sampling points were divided into two groups, and the measurement order was optimized using a greedy algorithm, such as... Figure 6 As shown, once all points in a group have been measured, the probe moves to a safe position and adjusts its posture to detect points in the next group.
[0039] The preferred safe position is determined based on the spatial relationship between the probe and the blade through a three-dimensional model of the blade disk, ensuring that the probe will not interfere with the blade disk when adjusting its posture.
[0040] It should be noted that the method proposed in this invention takes point-by-point on-machine measurement as an example, but it is not limited to on-machine measurement equipment. It is also applicable to equipment such as coordinate measuring machines for point-by-point measurement and has wide applicability.
[0041] This invention also provides a non-interference measurement path planning system for bladed disks based on non-perpendicular in-flight measurement, applying the aforementioned non-interference measurement path planning method for bladed disks, such as... Figure 7 As shown, the non-interference measurement path planning system for bladed disks includes: The feasible matrix acquisition module 1 is used to import the three-dimensional model of the blade of the blade, extract the sampling points of the blade of the blade from the three-dimensional model, and for each sampling point, obtain the first probe posture feasible matrix under different approach directions by non-perpendicular measurement, and determine the second probe posture feasible matrix that can be measured without interference under different probe postures and different approach directions based on each first probe posture feasible matrix. The probe posture planning module 2 is connected to the feasible matrix acquisition module 1. It is used to calculate the minimum probe posture required for all sampling points of non-interference measurement based on all second probe posture feasible matrices using a greedy algorithm, so as to plan the planned probe posture for each sampling point. The proximity direction planning module 3 is connected to the feasible matrix acquisition module 1 and the probe attitude planning module 2, respectively. It is used to select the proximity direction farthest from the interference boundary from the first probe attitude feasible matrix associated with the sampling point as the planned proximity direction of the sampling point based on the planned probe attitude of each sampling point. Measurement sequence planning module 4 is connected to probe posture planning module 2. It is used to group sampling points with the same planned probe posture into a group, and plan the measurement sequence of each sampling point in each group so that the on-machine measurement path is the shortest. Then, the sampling points of each group are measured in sequence.
[0042] In summary, this invention achieves the following significant technical effects through the innovative design of a non-perpendicular measurement strategy: 1. Enhanced measurement capability in narrow, easily interfered areas: By adopting a non-perpendicular measurement strategy, the inherent constraint that the approach direction must be along the normal of the sampling point in existing vertical measurements is overcome. The probe can avoid interference collisions by adjusting the approach direction in conjunction with the probe posture, rather than relying solely on adjusting the probe posture. This allows the probe to more flexibly avoid interference risks in the case of complex bladed disk structures and narrow flow channels, indirectly improving the effective measurement capability of narrow, easily interfered areas of bladed disks and solving the problem of measurement difficulties in such areas in existing technologies. 2. Improve measurement accuracy: By using a greedy algorithm to determine the minimum probe posture required for all sampling points in interference-free measurement, and rationally planning the combination of approach direction and probe posture, the number of probe posture adjustments is further reduced. The reduction in the number of probe posture adjustments can significantly reduce the positioning error caused by frequent positioning of the machine tool rotary axis, thereby effectively reducing the impact of such errors on the on-machine measurement accuracy, ensuring the accuracy of blade disk measurement data, and meeting the needs of high-precision manufacturing inspection. 3. Improve measurement efficiency: By grouping sampling points with the same planned probe posture into a group and optimizing the measurement sequence of sampling points within each group, the total length of the measurement path can be significantly shortened, thereby significantly improving the overall efficiency of in-machine measurement of blade disks and solving the problem of excessive measurement time in existing technologies.
[0043] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present invention.
Claims
1. A method for non-interference measurement path planning of bladed disks based on non-perpendicular on-machine measurement, characterized in that, include: Step S1: Import the three-dimensional model of the blade ... Step S2: Based on all the second probe posture feasible matrices, a greedy algorithm is used to calculate the minimum probe posture required for non-interference measurement of all the sampling points, so as to plan the planned probe posture for each sampling point. Step S3: Based on the planned probe posture of each sampling point, select the approach direction that is farthest from the interference boundary from the first probe posture feasible matrix associated with the sampling point as the planned approach direction of the sampling point; Step S4: The sampling points with the same planned probe posture are grouped into a group, and the measurement sequence of each sampling point in each group is planned to minimize the on-machine measurement path. Then, the sampling points in each group are measured in sequence.
2. The non-interference measurement path planning method for bladed disks according to claim 1, characterized in that, In step S1, the process of obtaining the first probe posture feasibility matrix under different approach directions by non-perpendicular measurement includes: Step S11: For each approach direction, continuously adjust the posture of the probe, and when the probe approaches the sampling point in the approach direction without colliding with the blade of the impeller in the posture, mark the corresponding posture as a feasible posture. Step S12: Construct the first probe posture feasibility matrix under each of the corresponding feasible postures in each approach direction.
3. The non-interference measurement path planning method for bladed disks according to claim 2, characterized in that, The probe's attitude includes an attitude tilt angle and an attitude rotation angle. The rows and columns of the first probe attitude feasible matrix correspond to the attitude tilt angle and the attitude rotation angle, respectively. The element values of the first probe attitude feasible matrix indicate whether a collision occurs.
4. The non-interference measurement path planning method for bladed disks according to claim 3, characterized in that, The approach direction includes the directional tilt angle and the directional rotation angle; Before performing step S11, the attitude tilt angle, attitude rotation angle, orientation tilt angle and orientation rotation angle are discretized respectively.
5. The non-interference measurement path planning method for bladed disks according to claim 2, characterized in that, In step S11, the process of determining whether the probe will collide with the blade of the impeller when it approaches the sampling point in the approach direction under the specified posture includes: Based on the three-dimensional model, the blade disk containing the blades is transformed into a triangular surface structure, and the probe is simplified into a ray. The area swept by the probe from the proximity point to the sampling point is simplified into a series of rays. If none of the rays pass through the triangular facet of the bladed disk, it is determined that approaching the sampling point in the approaching direction under the stated posture will not result in a collision with the bladed disk blades.
6. The non-interference measurement path planning method for bladed disks according to claim 1, characterized in that, In step S1, the second probe posture feasible matrix is obtained by performing a dot product operation on all the first probe posture feasible matrices.
7. The non-interference measurement path planning method for bladed disks according to claim 1, characterized in that, Step S2 includes: Step S21: Extract the sampling points that can be measured without interference under each probe posture from all the second probe posture feasible matrices and add them to the sampling point set; Step S22: Count the number of sampling points in each of the sampling point sets, and select the probe posture with the most sampling points. If there are multiple probe postures that meet the conditions, select the probe posture that is farthest from the interference boundary. Step S23: Remove the sampling point corresponding to the selected probe posture from each of the sampling point sets; Step S24: Repeat steps S22 to S23 until all sampling points are assigned corresponding probe postures, so as to plan the probe postures for each sampling point.
8. The non-interference measurement path planning method for bladed disks according to claim 1, characterized in that, In step S4, a greedy algorithm is used to plan the measurement sequence of each sampling point in each group so as to minimize the on-machine measurement path.
9. The non-interference measurement path planning method for bladed disks according to claim 1, characterized in that, In step S4, the measurement of each group of sampling points is performed sequentially, including: Move the probe to a preset safe position, and perform non-perpendicular on-machine measurements on each sampling point in each group according to the planned measurement sequence, with the planned probe posture and the planned approach direction. After each group of measurements is completed, return to the preset safe position, and then perform the next group of measurements until all sampling points are measured.
10. A non-interference measurement path planning system for bladed disks based on non-perpendicular on-machine measurement, characterized in that, The bladeless disk blade non-interference measurement path planning system, using the non-interference measurement path planning method for blades as described in any one of claims 1-9, comprises: The feasible matrix acquisition module is used to import the three-dimensional model of the blade of the blade, extract the sampling points of the blade of the blade from the three-dimensional model, and for each sampling point, obtain the first probe posture feasible matrix under different approach directions by non-perpendicular measurement, and determine the second probe posture feasible matrix that can be measured without interference under different probe postures and different approach directions based on each first probe posture feasible matrix. The probe posture planning module, connected to the feasible matrix acquisition module, is used to calculate the minimum probe posture required for non-interference measurement of all sampling points based on all the second probe posture feasible matrices using a greedy algorithm, so as to plan the planned probe posture for each sampling point. The proximity direction planning module is connected to the feasible matrix acquisition module and the probe attitude planning module, respectively. It is used to select the proximity direction farthest from the interference boundary from the first probe attitude feasible matrix associated with the sampling point as the planned proximity direction of the sampling point based on the planned probe attitude of each sampling point. The measurement sequence planning module, connected to the probe posture planning module, is used to group the sampling points with the same planned probe posture into a group, and plan the measurement sequence of each sampling point in each group to minimize the on-machine measurement path, and then perform the measurement of each group of sampling points in sequence.