Blade shape measurement method based on motion path planning, and optical scanning apparatus

Abstract

The present application relates to the technical field of optical scanning measurements, and specifically relates to a blade shape measurement method based on motion path planning, and an optical scanning apparatus. The blade shape measurement method based on motion path planning comprises: using a three-coordinate measurement machine to obtain profile discrete point data of a blade template to be measured, and fitting same into a blade profile; dividing the blade profile into four arc sections; arranging n reference points on each arc section, and making extension lines outwards from the reference points in a normal direction; sequentially connecting outer end points of all the extension lines to obtain a preliminarily planned motion path; using an optical scanning apparatus to measure and scan said blade template in view of the preliminarily planned motion path, so as to obtain a planned motion path; and on the basis of the planned motion path, measuring and scanning a blade to be measured. In the present application, a blade template to be measured is used, a blade profile is moved outwards in a normal direction to acquire measurement data, and a motion path planned by an optical scanning apparatus is then obtained, thereby reducing the deviation of a measurement result, and improving the measurement precision.

Description

Blade shape measurement method and optical scanning device based on motion path planning

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on January 30, 2024, with application number 202410132078.2 and invention name “Blade shape measurement method and optical scanning device based on motion path planning”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of optical scanning measurement technology, and in particular to a blade shape measurement method and an optical scanning device based on motion path planning. Background Art

[0004] 3D scanning using optical scanning devices primarily involves non-contact measurement of an object's spatial shape to obtain the spatial coordinates of its surface. This method offers advantages such as high speed and the ability to capture a wide range of measurement information. However, when measuring complex curved surfaces using an articulated arm measuring machine, the optical probe's varying angles and distances of incidence at the same point on the surface often lead to deviations in the measurement results.

[0005] Summary of the Invention

[0006] Therefore, the technical problem to be solved by this application is to overcome the defect that when using an articulated arm measuring machine to measure complex curved surfaces, the optical probe has different incident angles and incident distances on the same point of the surface, which often leads to deviations in the measurement results.

[0007] In order to solve the above problems, the present application provides a blade shape measurement method based on motion path planning, comprising:

[0008] Install the blade template to be tested onto the tooling base;

[0009] Use a three-dimensional coordinate measuring machine to perform contact shape measurement on the blade template to obtain the discrete point data of the blade template at different blade heights;

[0010] Fit the above profile discrete point data into a continuous blade profile;

[0011] The blade profile is divided into four arc segments: the leading edge arc segment, the trailing edge arc segment, the inner arc segment, and the outer arc segment. N reference points are arranged on each arc segment in a manner of equal arc length. An extension line of a set length is drawn outward from the reference point along the normal direction of the blade profile.

[0012] Connect the outer endpoints of all extension lines in sequence to obtain the preliminary planned motion path;

[0013] Using an optical scanning device to refer to the above-mentioned preliminary planned motion path, the corresponding outer end point and the direction of the corresponding extension line, measure and scan the blade template to be measured to obtain the planned motion path;

[0014] The blade to be measured is scanned by using an optical scanning device along the planned motion path.

[0015] Optionally, the set length is an optimal viewing distance of the optical scanning device.

[0016] Optionally, the normal direction of each reference point along the blade profile is obtained in a sketch module of a 3D modeling software.

[0017] Optionally, for the leading edge arc segment and the trailing edge arc segment, the angle between adjacent reference points along the normal line of the blade profile is no greater than 10°;

[0018] For the inner arc segment, the number of reference points n1 ≥ the arc length of the inner arc segment / W;

[0019] For the outer arc segment, the number of reference points n2 ≥ the arc length of the outer arc segment / W;

[0020] Wherein, W is the lateral field of view height of the optical scanning device.

[0021] Optionally, when the three-coordinate measuring machine is used to perform contact shape measurement on the blade template to be measured, the interval between different blade heights is no greater than the longitudinal field of view height H of the optical scanning device.

[0022] Optionally, when a three-coordinate measuring machine is used to perform contact shape measurement on the blade template to be measured, the interval between different blade height sections is the longitudinal field of view height H of the optical scanning device.

[0023] The present application also provides an optical scanning device, which is applied to the blade shape measurement method based on motion path planning, comprising:

[0024] An articulated arm measuring machine, with an optical probe at the end thereof; the articulated arm measuring machine is suitable for measuring and scanning using the optical probe;

[0025] An auxiliary mechanical arm component, detachably connected to the articulated arm measuring machine;

[0026] A control system is connected to the auxiliary manipulator component by signal; the control system is suitable for driving the articulated arm measuring machine to move through the auxiliary manipulator component according to the planned motion path, thereby enabling the optical probe to automatically perform measurement scanning.

[0027] Optionally, the articulated arm measuring machine includes:

[0028] A plurality of articulated arms are movably connected in sequence, and an optical measuring head is provided at the end of the articulated arm.

[0029] Optionally, the auxiliary robotic arm component includes:

[0030] Multiple robotic arms are movably connected in sequence, and the multiple robotic arms are detachably connected to the multiple articulated arms one by one, and the multiple robotic arms are respectively and parallelly arranged on the inner side or outer side of the multiple articulated arms, or the multiple robotic arms are respectively and parallelly arranged side by side with the multiple articulated arms.

[0031] Optionally, the number of the robotic arms is greater than the number of the articulated arms.

[0032] The above technical solution of the present application has the following advantages over the prior art:

[0033] 1. The present application provides a blade shape measurement method based on motion path planning, comprising: mounting a blade template to be measured on a tooling base; performing contact shape measurement of the blade template to be measured using a three-dimensional coordinate measuring machine to obtain discrete point data of the profile of the blade template to be measured at different blade heights; fitting the discrete point data of the profile into a continuous blade profile; dividing the blade profile into four arc segments: a leading edge arc segment, a trailing edge arc segment, an inner arc segment, and an outer arc segment; arranging n reference points on each arc segment in an equal arc length manner, and extending the blade profile outward by a set length from the reference point along the normal direction of the blade profile. Extension line; connect the outer endpoints of all extension lines in sequence to obtain a preliminary planned motion path; use an optical scanning device to refer to the above preliminary planned motion path, the corresponding outer endpoints and the direction of the corresponding extension line, measure and scan the blade template to be measured, and obtain the planned motion path; use an optical scanning device to measure and scan the blade to be measured with the above planned motion path; this application adopts the above technical solution, uses the blade template to be measured, and obtains measurement data by moving the blade profile outward along the normal direction, thereby obtaining the motion path planned by the optical scanning device; reduces the deviation in the measurement results and improves the measurement accuracy. For batches of blades to be measured with the same measurement requirements, it is only necessary to align the clamping position of the blade to be measured with the blade template to be measured, so as to achieve automatic and rapid measurement, which greatly saves measurement time and improves detection efficiency. In addition, by measuring the shape data with three coordinates, the initial data is obtained more accurately, ensuring the accuracy of the subsequent planned motion path.

[0034] 2. The set length described in this application is the optimal viewing distance of the optical scanning device; this application adopts the above technical solution, and the optical scanning device is always in the optimal viewing distance position, reducing measurement scanning errors.

[0035] 3. For the leading edge arc segment and the trailing edge arc segment, the angle between adjacent reference points along the normal of the blade profile is not greater than 10°; for the inner arc segment, the number of reference points n1 ≥ the arc length of the inner arc segment / W; for the outer arc segment, the number of reference points n2 ≥ the arc length of the outer arc segment / W; where W is the lateral field of view height of the optical scanning device; this application adopts the above technical solution to ensure measurement accuracy.

[0036] 4. When the present application utilizes a three-coordinate measuring machine to perform contact shape measurement on the blade template to be measured, the interval between different blade height sections is the longitudinal field of view height H of the optical scanning device; the present application adopts the above-mentioned technical solution to increase the interval between different blade height sections as much as possible within the scope of the scanning measurement capability of the optical scanning device, reduce the number of measuring points, and improve measurement efficiency.

[0037] 5. The optical scanning device provided in the present application is applied to the blade shape measurement method based on motion path planning, including: an articulated arm measuring machine, with an optical probe at the end; the articulated arm measuring machine is suitable for measuring and scanning using the optical probe; an auxiliary robotic arm component, which is detachably connected to the articulated arm measuring machine; a control system, which is signal-connected to the auxiliary robotic arm component; the control system is suitable for driving the articulated arm measuring machine to move through the auxiliary robotic arm component according to the planned motion path, thereby enabling the optical probe to automatically perform measurement scanning; the present application adopts the above-mentioned technical solution, and uses the optical scanning device to measure and scan the blade to be measured according to the planned motion path, so as to realize automatic and rapid measurement, greatly save measurement time, and improve detection efficiency.

[0038] 6. The number of robotic arms described in this application is greater than the number of articulated arms; this application adopts the above technical solution to ensure that the robotic arms have no fewer degrees of freedom than the articulated arms. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0040] FIG1 is a schematic diagram of a three-dimensional arrangement structure of an optical scanning device provided in an embodiment of the present application;

[0041] FIG2 is a schematic diagram of the arrangement structure for performing contact-type shape measurement of a blade template to be measured using a three-dimensional coordinate measuring machine according to an embodiment of the present application;

[0042] FIG3 is a schematic diagram of the horizontal field of view width, vertical field of view height, and optimal viewing distance of an optical scanning device provided in an embodiment of the present application;

[0043] FIG4 is a schematic diagram of the three-dimensional structure of a test platform provided in an embodiment of the present application;

[0044] FIG5 is a schematic diagram of a blade template to be measured provided in an embodiment of the present application when performing a measurement scan;

[0045] FIG6 is a schematic diagram of blade profile segments provided in an embodiment of the present application;

[0046] FIG7 is a schematic diagram of measuring and scanning a blade to be measured using an optical scanning device according to a planned motion path, provided in an embodiment of the present application.

[0047] Explanation of the accompanying symbols: 1. Blade template to be measured; 2. Tenon; 3. Tool base; 4. Wire; 5. Robotic arm; 6. Articulated arm measuring machine; 7. Control system; 8. Blade body; 9. Positioning pit; 10. Articulated arm; 11. Three-coordinate measuring machine; 12. Optical probe; 13. Test platform; 14. First normal; 15. Nth normal; 16. Light; 17. Leading edge; 18. Trailing edge; 19. Cross section. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solution of this application in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0049] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0050] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0051] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0052] With reference to FIG1 to FIG7 , the present application provides a blade profile measurement method based on motion path planning, comprising the following steps:

[0053] S1. As shown in FIG2 , the blade template 1 to be tested is mounted on the tooling base 3. As shown in FIG1 , the blade template 1 to be tested has a blade body 8 and a tenon 2.

[0054] S2. As shown in FIG2 , a three-coordinate measuring machine 11 is used to perform contact shape measurement on the blade template 1 to be measured, and discrete point data of the profile of the blade template 1 to be measured at different blade heights is obtained using the tooling base 3 to establish a coordinate system. When the three-coordinate measuring machine 11 is used to perform contact shape measurement on the blade template 1 to be measured, the intervals between sections 19 at different blade heights are no greater than the longitudinal field of view height H of the optical scanning device; specifically, as shown in FIG3 and FIG5 , when the three-coordinate measuring machine 11 is used to perform contact shape measurement on the blade template 1 to be measured, the intervals between sections 19 at different blade heights are the longitudinal field of view height H of the optical scanning device. When the optical scanning device scans the blade template 1 to be measured, a comprehensive measurement scan can be performed without omissions. The three-coordinate measuring machine 11 is a desktop three-coordinate measuring machine. The origin of the coordinate system of the tooling base 3 is set at the intersection of the two side surfaces on the tooling base 3.

[0055] S3. Fitting the above-mentioned discrete point data of the profile line into a continuous blade profile.

[0056] S4. As shown in Figures 3 and 6, the blade profile is divided into four arc segments: the leading edge segment LE, the trailing edge segment TE, the inner segment PS, and the outer segment SS. n reference points are arranged on each arc segment with equal arc lengths. Extended lines of a set length are drawn outward from the reference points along the normal direction of the blade profile. Specifically, the set length is the optimal viewing distance L of the optical scanning device. The normal direction of each reference point along the blade profile is obtained in the sketch module of the 3D modeling software. For the leading edge segment LE and the trailing edge segment TE, the angle between adjacent reference points along the blade profile normal is no greater than 10°. For the inner segment PS, the number of reference points n1 ≥ the arc length of the inner segment / W. For the outer segment SS, the number of reference points n2 ≥ the arc length of the outer segment / W. W is the lateral field of view height of the optical scanning device. As shown in Figures 3, 5, and 6, the optical scanning device includes an optical probe 12 that emits light 16. The distance between the optical probe 12 and the blade template 1 or the blade surface to be measured is the optimal viewing distance L of the optical scanning device. H is the height of the optical scanning device's longitudinal field of view, and W is the width of the optical scanning device's transverse field of view. In the inner arc segment PS, the first reference point corresponds to the first normal 14, and the nth reference point corresponds to the nth normal 15. The leading edge arc segment LE is close to the leading edge 17, and the trailing edge arc segment TE is close to the trailing edge 18.

[0057] S5. As shown in Figures 6 and 7, connect the outer endpoints of all extension lines in sequence to obtain the preliminary planned motion path way.

[0058] S6. As shown in FIG7 , an optical scanning device is used to measure and scan the blade template 1 to be measured by referring to the above-mentioned preliminary planned motion path way, the corresponding outer end point and the direction of the corresponding extension line to obtain the planned motion path way.

[0059] S7, using an optical scanning device to measure and scan the blade to be measured along the planned motion path way. The blade to be measured and the blade template to be measured 1 use the same tooling base 3 and are installed in the same position in the same installation method.

[0060] As shown in FIG1 and FIG4 , a specific embodiment of the optical scanning device is applied to the blade shape measurement method based on motion path planning. The optical scanning device includes: a control system 7, an auxiliary robotic arm component, and an articulated arm measuring machine 6 connected in sequence.

[0061] An optical probe 12 is provided at the distal end of the articulated arm measuring machine 6; the articulated arm measuring machine 6 is adapted to utilize the optical probe 12 for measurement scanning. The auxiliary robotic arm assembly is detachably connected to the articulated arm measuring machine 6. The control system 7 is signal-connected to the auxiliary robotic arm assembly. Specifically, the control system 7 and the auxiliary robotic arm assembly are signal-connected via a wire 4. The control system 7 is adapted to drive the articulated arm measuring machine 6 according to the planned motion path via the auxiliary robotic arm assembly, thereby enabling the optical probe 12 to automatically perform measurement scanning. The optical probe 12 is oriented directly in the direction normal to the blade profile.

[0062] The articulated arm measuring machine 6 and auxiliary robotic arm components are both fixed to the test platform 13. The blade template 1 and blade to be tested are secured to the test platform 13 via a fixture base 3. The fixture base 3 clamps the blade template 1 and the blade at the root of the blade to be tested, securing them. As shown in Figure 4, a positioning recess 9 with a depth of H0 is provided on the test platform 13, and the fixture base 3 is positioned using this recess.

[0063] The articulated arm measuring machine 6 includes: a plurality of articulated arms 10 movably connected in sequence, and an optical measuring head 12 is provided at the end of the articulated arm 10 .

[0064] The auxiliary robot arm component includes: a plurality of robot arms 5 that are movably connected in sequence, the plurality of robot arms 5 being detachably connected to the plurality of articulated arms 10 in a one-to-one correspondence, and the plurality of robot arms 5 being respectively and parallelly spaced apart and sleeved on the inner side or outer side of the plurality of articulated arms 10, or the plurality of robot arms 5 and the plurality of articulated arms 10 being respectively and parallelly spaced apart and arranged side by side. The position and angle data of the initially planned motion path way are input into the control system 7 as the planned motion path way of the optical probe 12, and then converted by the control system 7 into the motion path and rotation angle of the robot arm 5. The motion path and rotation angle of the robot arm 5 are obtained through coordinate conversion based on the positional relationship between the coordinate system of the tooling base 3 and the coordinate system of the test platform 13, and the planned motion path way of the optical probe 12.

[0065] Optionally, the number of the robotic arms 5 is greater than the number of the articulated arms 10 .

[0066] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of this application.

Claims

1. A blade shape measurement method based on motion path planning, characterized in that: include: Installing the blade template (1) to be tested onto the tooling base (3); Using a three-coordinate measuring machine (11) to perform contact-type shape measurement on the blade template (1) to be measured, and obtaining discrete point data of the profile of the blade template (1) to be measured at different blade heights; Fit the above profile discrete point data into a continuous blade profile; The blade profile is divided into four arc segments: the leading edge arc segment, the trailing edge arc segment, the inner arc segment, and the outer arc segment. N reference points are arranged on each arc segment in a manner of equal arc length. An extension line of a set length is drawn outward from the reference point along the normal direction of the blade profile. Connect the outer endpoints of all extension lines in sequence to obtain the preliminary planned motion path; Using an optical scanning device to refer to the above-mentioned preliminary planned motion path, the corresponding outer end point and the direction of the corresponding extension line, the blade template to be measured (1) is measured and scanned to obtain the planned motion path; The blade to be measured is scanned by using an optical scanning device along the planned motion path.

2. The blade shape measurement method based on motion path planning according to claim 1, characterized in that: The set length is the optimal viewing distance of the optical scanning device.

3. The blade shape measurement method based on motion path planning according to claim 1, characterized in that: The normal direction of each reference point along the blade profile is obtained in the sketch module of the 3D modeling software.

4. The blade shape measurement method based on motion path planning according to claim 1, characterized in that: For the leading edge arc segment and the trailing edge arc segment, the angle between adjacent reference points along the normal line of the blade profile shall not exceed 10°; For the inner arc segment, the number of reference points n1 ≥ the arc length of the inner arc segment / W; For the outer arc segment, the number of reference points n2 ≥ the arc length of the outer arc segment / W; Wherein, W is the lateral field of view height of the optical scanning device.

5. The blade shape measurement method based on motion path planning according to claim 1, characterized in that: When the three-coordinate measuring machine (11) is used to perform contact-type shape measurement on the blade template (1) to be measured, the intervals between different blade heights are no greater than the longitudinal field of view height H of the optical scanning device.

6. The blade shape measurement method based on motion path planning according to claim 5, characterized in that: When a three-coordinate measuring machine (11) is used to perform contact-type shape measurement on a blade template (1) to be measured, the interval between different blade height sections (19) is the longitudinal field of view height H of an optical scanning device.

7. An optical scanning device, applied to the blade profile measurement method based on motion path planning according to any one of claims 1 to 6, characterized in that: include: An articulated arm measuring machine (6) having an optical measuring head (12) at the end thereof; The articulated arm measuring machine (6) is suitable for performing measurement scanning using an optical measuring head (12); An auxiliary mechanical arm component, detachably connected to the articulated arm measuring machine (6); A control system (7) is connected to the auxiliary manipulator component by signal; the control system (7) is adapted to drive the articulated arm measuring machine (6) to move according to the planned motion path through the auxiliary manipulator component, thereby enabling the optical probe (12) to automatically perform measurement scanning.

8. The optical scanning device according to claim 7, wherein: The articulated arm measuring machine (6) comprises: Multiple articulated arms (10) are movably connected in sequence, and the articulated arms (10) at the end are provided with optical measuring Head (12).

9. The optical scanning device according to claim 8, wherein: The auxiliary mechanical arm components include: The plurality of mechanical arms (5) are movably connected in sequence, and the plurality of mechanical arms (5) are detachably connected to the plurality of articulated arms (10) in a one-to-one correspondence. The plurality of mechanical arms (5) are respectively arranged in parallel and at intervals on the inner side or the outer side of the plurality of articulated arms (10), or the plurality of mechanical arms (5) and the plurality of articulated arms (10) are respectively arranged in parallel and at intervals.

10. The optical scanning device according to claim 9, wherein The number of the mechanical arms (5) is greater than the number of the articulated arms (10).

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