Assembly method and apparatus for special-shaped curved part in helicopter

Abstract

The present invention relates to the technical field of parts assembly, and in particular to an assembly method and apparatus for a special-shaped curved part in a helicopter. In the present invention, before a target part is assembled, planned scanning paths for scanning the target part and a target airframe are respectively determined; on the basis of the scanning results obtained by scanning according to the planned scanning paths, a first model corresponding to the target part and a second model corresponding to the target airframe are built, and the first model and second model thus obtained are more closely aligned with physical products, and can accurately reflect the positions and postures of the target part and the target airframe; and therefore, by comparing the first model and the second model, a contact stress distribution pattern during the assembly of the target part and the target airframe is predicted, so that before assembling the target part to the target airframe, an operator can perform assembly using an assembly robot on the basis of the contact stress distribution pattern, thereby preventing the target part from being damaged by excessive contact stress.

Description

Method and device for assembling special-shaped curved component in helicopter TECHNICAL FIELD

[0001] The present application relates to the technical field of component assembly, and in particular to a method and device for assembling special-shaped curved component in a helicopter. BACKGROUND

[0002] In the process of assembling components including special-shaped curved surfaces, such as the process of assembling windshield glass in a large helicopter, the traditional assembly method is to directly align the windshield glass to the helicopter skeleton by a worker operating a mechanical arm of an assembly robot. During the alignment process, the contact surface between the windshield glass and the skeleton is a special-shaped complex curved surface, and the windshield glass is also a high-brightness complex curved surface. When the position of the windshield glass is determined by a camera held by the mechanical arm, the image of the windshield glass captured by the camera is not clear, which leads to inaccurate determination of the position and posture of the windshield glass, and further leads to failure of the mechanical arm to pick up the windshield glass or damage to the windshield glass.

[0003] In addition, during the process of directly aligning the windshield glass to the helicopter skeleton, some defects (such as a shape of an assembly hole that does not correspond, deformation, abnormal protrusions, etc.) exist on the windshield glass or the helicopter skeleton, which will cause contact stress during the installation process, leading to damage to the windshield glass. Even if the windshield glass is safely installed on the helicopter skeleton, it may be damaged due to contact stress during the subsequent use of the helicopter, which is very unsafe.

[0004] Therefore, the present application provides a method and device for assembling special-shaped curved component in a helicopter to solve the above technical problems. SUMMARY

[0005] The present application describes a method and device for assembling special-shaped curved component in a helicopter, which can reduce damage to the component during assembly.

[0006] According to a first aspect, the present application provides a method for assembling special-shaped curved component in a helicopter, comprising:

[0007] According to the edge features corresponding to the target component and the target skeleton to be assembled respectively, a planned scanning path for scanning the target component and the target skeleton is determined respectively; wherein the target component includes a special-shaped curved component;

[0008] The target component and the target skeleton are scanned according to the planned scanning path, and a first model corresponding to the target component and a second model corresponding to the target skeleton are established based on the obtained scanning results;

[0009] The first model and the second model are compared, and a contact stress distribution diagram when the target accessory and the target framework are assembled is predicted based on a comparison result;

[0010] The target accessory is assembled to the target framework using an assembly robot according to the contact stress distribution diagram.

[0011] According to a second aspect, the application provides an assembly device for a special-shaped curved accessory in a helicopter, comprising:

[0012] A planning unit is configured to determine a planned scanning path for scanning the target accessory and the target framework respectively according to the edge features corresponding to the target accessory and the target framework respectively, wherein the target accessory comprises a special-shaped curved accessory;

[0013] A modeling unit is configured to scan the target accessory and the target framework according to the planned scanning path, and establish a first model corresponding to the target accessory and a second model corresponding to the target framework based on the obtained scanning results;

[0014] A prediction unit is configured to compare the first model and the second model, and predict a contact stress distribution diagram when the target accessory and the target framework are assembled based on a comparison result;

[0015] An assembly unit is configured to assemble the target accessory to the target framework using an assembly robot according to the contact stress distribution diagram.

[0016] According to the assembly method and device for a special-shaped curved accessory in a helicopter provided by the application, the planned scanning path for scanning the target accessory and the target framework is determined respectively before the target accessory is assembled, the first model corresponding to the target accessory and the second model corresponding to the target framework are established based on the scanning results obtained according to the planned scanning path, the first model and the second model obtained in this way are more fitted to the real object, and can accurately reflect the position and posture of the target accessory and the target framework. Then, the first model and the second model are compared, a contact stress distribution diagram when the target accessory and the target framework are assembled is predicted, so that the worker can use the assembly robot to assemble the target accessory to the target framework according to the contact stress distribution diagram before the target accessory is assembled to the target framework, and the damage of the target accessory caused by excessive contact stress can be avoided in advance. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0018] FIG. 1 shows a flowchart of an assembly method of a special-shaped curved component in a helicopter according to an embodiment;

[0019] FIG. 2 shows a flowchart of an assembly method of a special-shaped curved component in a helicopter according to another embodiment;

[0020] FIG. 3 shows a schematic block diagram of an assembly device of a special-shaped curved component in a helicopter according to an embodiment. DETAILED DESCRIPTION

[0021] The scheme provided by the present application is described below in conjunction with the accompanying drawings.

[0022] FIG. 1 shows a flowchart of an assembly method of a special-shaped curved component in a helicopter according to an embodiment. It can be understood that the method can be executed by any device, equipment, platform, cluster of equipment with computing and processing capabilities. As shown in FIG. 1, the method comprises:

[0023] Step 101, determining a planned scanning path for scanning the target component and the target skeleton respectively according to the edge features corresponding to the target component and the target skeleton respectively; wherein the target component comprises a special-shaped curved component.

[0024] In the present embodiment, the target component refers to a component comprising a special-shaped curved surface, such as a windshield and a cabin door of a large helicopter before assembly. The target skeleton refers to a blank skeleton to which the target component is to be installed, such as a helicopter skeleton. In the present embodiment, the target component is clamped to the target skeleton by a mechanical arm of an assembly robot to realize assembly of the target component and the target skeleton.

[0025] Step 102, scanning the target component and the target skeleton according to the planned scanning path, and establishing a first model corresponding to the target component and a second model corresponding to the target skeleton based on the obtained scanning results.

[0026] The planned scanning path refers to a path for scanning the target component and the target skeleton by a 3D scanner clamped at the end of a mechanical arm of an assembly robot. The target component and the target skeleton correspond to at least one planned scanning path respectively. Exemplarily, the planned scanning path corresponding to the target component indicates multiple positions on the target component that need to be photographed by the 3D scanner, and a photographing order of the multiple positions.

[0027] In this embodiment, the accessory with a high-brightness special-shaped complex curved surface such as a windshield has the following difficulties in modeling by directly shooting an image by a depth camera in the related art: the high-brightness background causes local exposure and environmental reflection in the shot image, resulting in unclear imaging; and the irregular contour of the special-shaped curved surface cannot present the irregular features of the special-shaped curved surface in the shot image, and the defects (such as abnormal protrusions) of the edge contour of the special-shaped curved surface are also not clear in the image due to unclear imaging.

[0028] The embodiment designs a planned scanning path for scanning the target accessory and the target skeleton, and obtains a plurality of scanning images by step-by-step scanning of the target accessory and the target skeleton, so as to improve the modeling accuracy of the target accessory and the target skeleton.

[0029] In step 103, the first model and the second model are compared, and a contact stress distribution map of the target accessory and the target skeleton when assembled is predicted based on the comparison result.

[0030] The contact stress distribution map is used to represent the contact stress that the target accessory will bear when the target accessory and the target skeleton are assembled. The contact stress is mainly caused by the following factors: the contact stress caused by the mismatch of the shape or position of the assembly hole when the target accessory and the target skeleton are connected by screws or the like; the contact stress caused by the abnormal protrusions or depressions on the target accessory or the target skeleton when the edges of the two are fitted; and the contact stress caused by the deformation of the target accessory or the target skeleton when the edges of the two are fitted.

[0031] In step 104, the target accessory is assembled to the target skeleton by using an assembly robot according to the contact stress distribution map.

[0032] In specific implementation, a professional assembly worker can determine whether to assemble according to the contact stress distribution map. After obtaining the contact stress distribution map, the professional assembly worker can determine whether to directly assemble or to modify the target accessory or the target skeleton before assembling according to professional knowledge.

[0033] In the embodiment, before assembling the target accessory, a planned scanning path for scanning the target accessory and the target skeleton is determined respectively, a first model corresponding to the target accessory and a second model corresponding to the target skeleton are established based on scanning results obtained according to the planned scanning path, and the first model and the second model obtained in this way are more fitted to the real object and can accurately reflect the position and posture of the target accessory and the target skeleton. Then, the first model and the second model are compared to predict a contact stress distribution map of the target accessory and the target skeleton when they are assembled, so that the worker can use the assembly robot to assemble before the target accessory is assembled to the target skeleton according to the contact stress distribution map, and damage of the target accessory caused by excessive contact stress can be avoided in advance.

[0034] The execution mode of each step shown in FIG. 1 is described below.

[0035] For step 101:

[0036] In an embodiment of the application, the method for obtaining the edge feature in step 101 includes:

[0037] A depth camera installed by the assembly robot obtains a photo corresponding to the target accessory and a photo corresponding to the target skeleton respectively;

[0038] A first initial model corresponding to the target accessory and a second initial model corresponding to the target skeleton are established based on the photos;

[0039] Feature analysis is performed on the first initial model and the second initial model to obtain edge features corresponding to the target accessory and the target skeleton respectively.

[0040] In the embodiment, after the approximate positions of the target accessory and the target skeleton are determined, the target accessory and the target skeleton are photographed by the depth camera installed by the assembly robot to obtain at least one photo corresponding to the target accessory and at least one photo corresponding to the target skeleton respectively. A first initial model corresponding to the target accessory is established based on the photo corresponding to the target accessory, and a second initial model corresponding to the target skeleton is established based on the photo corresponding to the target skeleton. The first initial model and the second initial model are relatively rough because they are directly modeled using the photos, so the target accessory and the target skeleton need to be scanned further according to the planned scanning path below, and a first model corresponding to the target accessory and a second model corresponding to the target skeleton are established based on the obtained scanning results.

[0041] The establishment of the first initial model corresponding to the target accessory and the second initial model corresponding to the target skeleton based on the photos can refer to 3D modeling in related technologies, and the application is not limited in this regard.

[0042] As an embodiment, the feature analysis performed on the first initial model and the second initial model to obtain the edge features corresponding to the target accessory and the target skeleton respectively includes:

[0043] identify and mark each corner on the outer edge of the first initial model and the second initial model;

[0044] characteristics of the marked corners in the first initial model as the edge characteristics corresponding to the target accessory, and characteristics of the marked corners in the second initial model as the edge characteristics corresponding to the target skeleton.

[0045] In the embodiment, each corner on the outer edge of the first initial model and the second initial model refers to the corner protruding from the outer contour of the first initial model and the second initial model. For example, if the target accessory is a windshield, the corners on the outer edge of the first initial model actually correspond to the four corners of the windshield. Here, the identification of each corner on the outer edge of the first initial model and the second initial model is mainly to determine the outer edge of the first initial model and the second initial model.

[0046] For step 101, the planned scanning path for scanning the target accessory and the target skeleton is determined based on the edge characteristics corresponding to the target accessory and the target skeleton, respectively. Specifically, it can include the following steps:

[0047] Determine the position coordinates of the target accessory and the target skeleton relative to the assembly robot and the contour coordinates of the target accessory and the target skeleton based on the edge characteristics corresponding to the target accessory and the target skeleton, respectively;

[0048] Determine the direction change and position change of the 3D scanner used when scanning the target accessory and the target skeleton based on the position coordinates and the contour coordinates;

[0049] Determine the direction change and position change of the 3D scanner as the planned scanning path for scanning the target accessory and the target skeleton.

[0050] In the embodiment, the position coordinates of the assembly robot are known, and the position coordinates of the target accessory and the target skeleton relative to the assembly robot can be determined based on the position coordinates of the assembly robot, the distance between the assembly robot and the target accessory, and the target skeleton. The distance between the assembly robot and the target accessory and the target skeleton can be determined by the photos taken when determining the edge characteristics corresponding to the target accessory and the target skeleton.

[0051] Further, based on the position coordinates of the assembly robot and the position coordinates of the target accessory and the target skeleton relative to the assembly robot, the contour coordinates of the target accessory and the target skeleton can be further determined. The contour coordinates here can be the coordinates of the corners corresponding to the edge characteristics determined in the above embodiment.

[0052] As an embodiment, for the target accessory or the target framework, the direction change and the position change of the 3D scanner used for scanning the target accessory or the target framework can be determined based on the corresponding position coordinates and contour coordinates thereof, the range of the region to be scanned by the 3D scanner can be determined by the position coordinates, the direction change of the 3D scanner can be determined by the change direction of the coordinate values in the contour coordinates, and the corresponding position of the 3D scanner can be determined according to the position of the contour coordinates in the change direction.

[0053] In a specific implementation, after the scanning path is planned, the target accessory and the target framework are scanned according to the planned scanning path, including:

[0054] For the direction change and the position change of the 3D scanner, a motion scheme of each joint of the mechanical arm clamping the 3D scanner is planned;

[0055] The 3D scanner clamped by the mechanical arm is controlled based on the motion scheme to scan the target accessory and the target framework.

[0056] In this embodiment, the motion scheme of each joint of the mechanical arm clamping the 3D scanner is planned based on the principles of robot kinematics and the planned scanning path, and the principles of robot kinematics can refer to related technologies, which will not be described here.

[0057] The motion scheme is used to control the mechanical arm to scan the target accessory and the target framework according to the planned scanning path.

[0058] Based on the process of scanning completed by the mechanical arm clamping the 3D scanner, for step 102:

[0059] Based on the obtained scanning results, a first model corresponding to the target accessory and a second model corresponding to the target framework are established, including:

[0060] The first model corresponding to the target accessory and the second model corresponding to the target framework are established by combining the motion trajectory formed after the scanning completed by the mechanical arm clamping the 3D scanner and the plurality of scanning photos obtained by the 3D scanner.

[0061] It should be noted that the plurality of scanning photos obtained by the 3D scanner are not global photos of the target accessory and the target framework, but are local detail photos of the target accessory and the target framework, so the first model and the second model established by combining the motion trajectory formed after the scanning completed by the mechanical arm clamping the 3D scanner and the plurality of scanning photos obtained by the 3D scanner can accurately reflect the details of the target accessory and the target framework.

[0062] Preferably, the first model and the second model can be established by optimizing the first initial model and the second initial model to obtain the first model and the second model that are more consistent with the real object by combining the global image presented by the photos.

[0063] A flowchart of an assembly method of a special-shaped curved fitting in a helicopter according to another embodiment shown in FIG. 2 is described below. It can be understood that the method can be executed by any device, equipment, platform, cluster of equipment with computing and processing capabilities. As shown in FIG. 2, the method comprises:

[0064] Step 201, determining a planned scanning path for scanning the target fitting and the target skeleton respectively according to the edge features corresponding to the target fitting and the target skeleton respectively; wherein the target fitting comprises a special-shaped curved surface;

[0065] Step 202, scanning the target fitting and the target skeleton according to the planned scanning path, and establishing a first model corresponding to the target fitting and a second model corresponding to the target skeleton based on the obtained scanning results;

[0066] The description of steps 201 and 202 above can refer to the description of FIG. 1, which will not be repeated here.

[0067] Step 203, determining, for the first model and the second model, a defect position where contact stress exists when the first model and the second model are fitted to simulate the assembly of the target fitting and the target skeleton, and a predicted contact stress corresponding to the defect position;

[0068] As an embodiment, the predicted contact stress corresponding to each defect position can be calculated by the following way:

[0069] First, a soft body mechanics model that can represent the relationship between the deformation of the target fitting and the force moment is established according to the known stiffness of the target fitting, and then based on the fitting of the target fitting and the target skeleton, the contact stress is generated due to the height difference at the defect position, and the generated contact stress is to make the target fitting deform to adapt to the height difference. Therefore, for each defect position, the deformation degree of each defect position on the target fitting when the target skeleton is fitted at different postures can be estimated by a simulation test, and then according to the stiffness of the target fitting and the deformation degree of the defect position, the force moment (i.e. the predicted contact stress) corresponding to the deformation of the defect position due to the height difference is determined.

[0070] Step 204, obtaining the geometric and positional error of each defect position; wherein the geometric and positional error comprises a height error and a shape error;

[0071] In this embodiment, the height error refers to the height difference generated when the first model and the second model are fitted. Ideally, the height difference after the first model and the second model are fitted should be 0. However, due to the possible deformation or protrusion, depression and other defects of the first model and the second model, there may be height difference at some point positions after the first model and the second model are fitted. The height error is represented by the three-dimensional coordinates corresponding to the defect positions. The shape error mainly refers to the error of the shape inconsistency and position inconsistency of the corresponding part of the assembly hole of the first model and the second model when the first model and the second model are fitted. The shape error is represented by the two-dimensional coordinates corresponding to the defect positions.

[0072] In step 205, a mapping equation between the shape and position error of each defect position and the corresponding predicted contact stress is established according to the shape and position error of each defect position and the corresponding predicted contact stress.

[0073] As an embodiment, it is assumed that the mapping equation between the shape and position error and the contact stress is: shape and position error * k = contact stress. The predicted contact stress and the shape and position error corresponding to each defect position are known through the above steps of the embodiment, but the coefficient k is unknown. Therefore, the mapping equation between the shape and position error and the contact stress needs to calculate the value of k. Exemplarily, k can be obtained by equation fitting of the shape and position error and the contact stress.

[0074] In step 206, the edges of the first model and the second model are compared and matched according to the mounting direction of the target accessory to the target skeleton, and the corresponding chromatogram when the first model and the second model are fitted is obtained. The chromatogram is used to represent the shape and position error of each point on the edge of the first model and the second model.

[0075] In this embodiment, the edges of the first model and the second model are compared and matched by simulation, and the height error and shape error (here mainly the height difference) existing on the fitting contact surface (i.e. the edge) of the first model and the second model are obtained. Since the shape and position error on the fitting contact surface of the first model and the second model has formed a surface from points, the shape and position error of each point on the edge of the first model and the second model is represented by the chromatogram in this embodiment. Exemplarily, the deeper the color of the chromatogram, the greater the shape and position error at that position.

[0076] In step 207, the fitting of the first model and the second model is digitally simulated based on the chromatogram and the mapping equation, and the contact stress distribution diagram when the target accessory and the target skeleton are assembled is predicted.

[0077] Here, the fitting of the first model and the second model based on the chromatogram and the mapping equation is digitally simulated, which can refer to related digital simulation technology. The simulation technology is not limited in this application.

[0078] Step 208, according to the contact stress distribution map, using the assembly robot, assembling the target accessory to the target skeleton.

[0079] In summary, before assembling the target accessory, the planned scanning path for scanning the target accessory and the target skeleton is determined respectively, the first model corresponding to the target accessory and the second model corresponding to the target skeleton are established based on the scanning results obtained according to the planned scanning path, and the first model and the second model obtained in this way are more fitted to the real object, which can accurately reflect the position and posture of the target accessory and the target skeleton. Then, the mapping equation between the form error and the contact stress is derived by predicting the contact stress of the defect position, and then the contact stress distribution map of the target accessory and the target skeleton during assembly is predicted based on the chromatogram for representing the form error of the whole target accessory and target skeleton when they are fitted. The prediction is more reasonable and accurate, and the worker can use the assembly robot to assemble according to the contact stress distribution map before assembling the target accessory to the target skeleton, so as to avoid damage to the target accessory caused by excessive contact stress in advance.

[0080] The execution mode of each step shown in FIG. 2 is described below.

[0081] For step 203:

[0082] Determine the defect position where the first model and the second model are fitted to simulate the assembly of the target accessory and the target skeleton to exist contact stress, comprising:

[0083] Identify and mark each defect point and assembly hole in the first model and the second model; wherein the defect point is the position of the abnormal protrusion and / or abnormal depression carried by the target accessory and the target skeleton when leaving the factory;

[0084] For each defect position and assembly hole, calculate the area feature, gray feature and gradient feature corresponding to the defect position and assembly hole respectively as the defect feature corresponding to the defect position and assembly hole respectively;

[0085] Compare each defect point and assembly hole in the first model and the second model, and based on the comparison result and the defect feature corresponding to each defect point and assembly hole, obtain the form error corresponding to each defect point and assembly hole;

[0086] The defect point and / or assembly hole whose form error meets the preset rule for generating contact stress is determined as the defect position.

[0087] In the embodiment, before identifying and marking each defect point and assembly hole in the first model and the second model, the first model and the second model can be preprocessed by denoising (including removing noise from the image in the contact surface (i.e., the surface that adheres when the two are assembled) of the first model and the second model) and region segmentation (here, the region segmentation is performed because the target accessory is too large, and the image is segmented into small blocks for processing).

[0088] After identifying and marking each defect point and assembly hole in the first model and the second model, the position of each defect point can be determined according to the region feature, gray feature, and gradient feature of the pixel point corresponding to the defect point being different from the surrounding pixel points, and the height difference with the surrounding adjacent points, and the position of the assembly hole can be determined according to the preset position corresponding to the assembly hole and the region feature, gray feature, and gradient feature of the pixel point corresponding to the assembly hole being different from the surrounding pixel points, and the height difference with the surrounding adjacent points and the shape of the assembly hole.

[0089] As an embodiment, based on the assembly relationship between the first model and the second model, the assembly holes need to correspond to each other when the two are assembled, therefore, by comparing each defect point and assembly hole in the first model and the second model, the shape and position of the assembly holes with the same coordinates can be compared to determine the height error and shape error corresponding to the assembly holes, and the defect points in one model and the corresponding points in the other model can be compared to determine the height error and shape error corresponding to the defect points.

[0090] Preferably, in the embodiment, the comparison result obtained by comparing each defect point and assembly hole in the first model and the second model can be taken as the first comparison result, the comparison result obtained by comparing each defect point and assembly hole in the first model with the first standard model can be taken as the second comparison result, and the comparison result obtained by comparing each defect point and assembly hole in the second model with the second standard model can be taken as the third comparison result, and the first comparison result, the second comparison result, and the third comparison result are integrated to determine the shape and position error corresponding to each defect point and assembly hole. The first standard model refers to a standard model corresponding to an ideal target accessory without any defects, and the second standard model refers to a standard model corresponding to an ideal target skeleton without any defects.

[0091] Finally, in the embodiment, the preset rule for generating contact stress can be that when the corresponding height error is greater than a preset height error and / or the shape error is greater than a preset shape error, the defect point or the assembly hole in the first model or the second model will generate contact stress.

[0092] For step 205:

[0093] According to the form and position error of each defect position and the corresponding predicted contact stress, a mapping equation between the form and position error and the contact stress is established, including:

[0094] For the first model, according to the form and position error of each defect position and the corresponding predicted contact stress, the stiffness of the target assembly, the rigid body coordinates of the simulated contact point between the assembly robot and the first model, and the flexible body coordinates of each assembly hole position on the first model relative to the simulated contact point, a mapping equation between the form and position error and the contact stress is established.

[0095] In this embodiment, the contact stress is related to the stiffness of the target assembly, the rigid body coordinates of the simulated contact point, and the flexible body coordinates of each assembly hole position relative to the simulated contact point, etc. In addition, in step 203, different poses of the target skeleton have a corresponding relationship with the rigid body coordinates of the simulated contact point. In the case where the pose of the target skeleton is determined, the rigid body coordinates of the simulated contact point are also known. The flexible body coordinates of each assembly hole position relative to the simulated contact point have a corresponding relationship with the rigid body coordinates. In the case where the rigid body coordinates are known, the flexible body coordinates can be calculated according to the rigid body coordinates. Therefore, preferably, in this embodiment, when k is calculated, k can be set to include the rigid body coordinates, the flexible body coordinates, the stiffness of the target assembly, etc. The corresponding predicted contact stress and the rigid body coordinates under multiple poses of the target skeleton are integrated to calculate the final k.

[0096] The rigid body coordinates of the simulated contact point between the assembly robot and the first model refer to the coordinates of the simulated contact point between the assembly robot and the first model. The flexible body coordinates of each assembly hole position on the first model relative to the contact point refer to the following: When the target assembly is a weak rigid structure, the target assembly may be slightly deformed when gripped by the assembly robot, which may cause slight coordinate changes of each assembly hole position. The coordinate changes cause the position coordinates of each assembly hole position to change relative to the rigid body coordinates of the simulated contact point, so the position coordinates of the changed assembly hole position are the flexible body coordinates.

[0097] At this point, the description of the flow shown in FIG. 2 is completed.

[0098] The above describes specific embodiments of the application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order other than that described in the embodiments and still achieve desirable results. In addition, the processes depicted in the figures do not necessarily require the particular order shown or sequential order to achieve the desired results. In certain implementations, multitasking and parallel processing can be advantageous or possible.

[0099] According to another aspect, the present application provides an assembly device for a special-shaped curved component in a helicopter. FIG. 3 shows a schematic block diagram of an assembly device for a special-shaped curved component in a helicopter according to an embodiment. It can be understood that the device can be implemented by any device, equipment, platform and cluster of equipment with computing and processing capabilities. As shown in FIG. 3, the device comprises a planning unit 301, a modeling unit 302, a prediction unit 303 and an assembly unit 304. The main functions of each component unit are as follows:

[0100] The planning unit 301 is configured to determine a planned scanning path for scanning the target component and the target skeleton respectively according to the edge features corresponding to the target component and the target skeleton respectively; wherein the target component comprises a special-shaped curved component.

[0101] The modeling unit 302 is configured to scan the target component and the target skeleton according to the planned scanning path, and to establish a first model corresponding to the target component and a second model corresponding to the target skeleton based on the obtained scanning results.

[0102] The prediction unit 303 is configured to compare the first model and the second model, and to predict a contact stress distribution map when the target component and the target skeleton are assembled based on the comparison result.

[0103] The assembly unit 304 is configured to assemble the target component to the target skeleton using an assembly robot according to the contact stress distribution map.

[0104] As a preferred implementation, the device further comprises an acquisition unit configured to:

[0105] acquire photos corresponding to the target component and the target skeleton respectively by a depth camera installed on the assembly robot;

[0106] establish a first initial model corresponding to the target component and a second initial model corresponding to the target skeleton based on the photos;

[0107] perform feature analysis on the first initial model and the second initial model to obtain edge features corresponding to the target component and the target skeleton respectively.

[0108] As a preferred implementation, the acquisition unit, when performing feature analysis on the first initial model and the second initial model to obtain edge features corresponding to the target component and the target skeleton respectively, comprises:

[0109] identifying and marking each corner at the outer edge of the first initial model and the second initial model;

[0110] The features of the marked corners in the first initial model are taken as the edge features corresponding to the target fitting part, and the features of the marked corners in the second initial model are taken as the edge features corresponding to the target skeleton.

[0111] As a preferred implementation, the planning unit 301 determines the position coordinates of the target fitting part and the target skeleton relative to the assembly robot and the contour coordinates of the target fitting part and the target skeleton according to the edge features corresponding to the target fitting part and the target skeleton respectively;

[0112] Based on the position coordinates and the contour coordinates, the direction change and the position change of the 3D scanner used when scanning the target fitting part and the target skeleton are determined;

[0113] The direction change and the position change of the 3D scanner are determined as the planned scanning path for scanning the target fitting part and the target skeleton.

[0114] As a preferred implementation, the modeling unit 302 scans the target fitting part and the target skeleton according to the planned scanning path, including:

[0115] For the direction change and the position change of the 3D scanner, a motion scheme for clamping the joints of the mechanical arm of the 3D scanner is planned;

[0116] Based on the motion scheme, the mechanical arm clamping the 3D scanner is controlled to scan the target fitting part and the target skeleton;

[0117] The modeling unit 302 establishes the first model corresponding to the target fitting part and the second model corresponding to the target skeleton based on the obtained scanning results, including:

[0118] Combined with the motion trajectory formed after the mechanical arm clamping the 3D scanner completes scanning and the plurality of scanning photos obtained by the 3D scanner, the first model corresponding to the target fitting part and the second model corresponding to the target skeleton are established.

[0119] As a preferred implementation, the device further includes an equation establishing unit for:

[0120] For the first model and the second model, the defect positions where contact stress exists when the first model and the second model are fitted to simulate the assembly of the target fitting part and the target skeleton, and the predicted contact stress corresponding to the defect positions are determined;

[0121] Obtain the geometric and position errors of the defect positions, including height errors and shape errors;

[0122] According to the form and position error of each defect position and the corresponding predicted contact stress, a mapping equation between the form and position error and the contact stress is established.

[0123] As a preferred implementation, the equation establishing unit determines that the first model and the second model are fitted to simulate the defect position where the contact stress exists when the target accessory and the target skeleton are assembled, including:

[0124] Identify and mark each defect point and assembly hole in the first model and the second model; the defect point is the position of the abnormal protrusion and / or abnormal depression carried by the target accessory and the target skeleton when leaving the factory;

[0125] For each defect position and assembly hole, calculate the area feature, gray feature and gradient feature corresponding to the defect position and assembly hole respectively as the defect feature corresponding to the defect position and assembly hole respectively;

[0126] Compare each defect point and assembly hole in the first model and the second model, and obtain the form and position error corresponding to each defect point and assembly hole based on the comparison result and the defect feature corresponding to each defect point and assembly hole;

[0127] The defect point and / or assembly hole whose form and position error meets the preset rule of generating contact stress is determined as the defect position.

[0128] As a preferred implementation, the equation establishing unit establishes a mapping equation between the form and position error and the contact stress according to the form and position error of each defect position and the corresponding predicted contact stress, including:

[0129] For the first model, according to the form and position error of each defect position and the corresponding predicted contact stress, combined with the stiffness of the target accessory, the rigid body coordinates of the simulated contact point between the assembly robot and the first model, and the flexible body coordinates of each assembly hole on the first model relative to the simulated contact point, a mapping equation between the form and position error and the contact stress is established.

[0130] Compare the first model and the second model, and predict the contact stress distribution diagram when the target accessory and the target skeleton are assembled based on the comparison result, including:

[0131] As a preferred implementation, the prediction unit 303 compares the first model and the second model, and predicts the contact stress distribution diagram when the target accessory and the target skeleton are assembled based on the comparison result, including:

[0132] According to an installation direction of the target accessory to the target framework, the edges of the first model and the second model are matched to obtain a corresponding chromatogram when the first model and the second model are fitted, and the chromatogram is used to represent the shape and position error of each point on the edges of the first model and the second model.

[0133] Based on the chromatogram and the mapping equation, the fitting of the first model and the second model is digitally simulated to predict a contact stress distribution map when the target accessory and the target framework are assembled.

[0134] According to another aspect of the embodiments, a computer readable storage medium is also provided, which stores a computer program, and when the computer program is executed in a computer, the computer executes the method described in combination with FIG. 1.

[0135] According to another aspect of the embodiments, an electronic device is also provided, which includes a memory and a processor, the memory stores executable code, and when the processor executes the executable code, the method described in combination with FIG. 1 is implemented.

[0136] Each of the embodiments in the present application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment mainly describes the difference from other embodiments. Especially, for the device embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the related parts can be referred to the part of the method embodiments.

[0137] Those skilled in the art should realize that, in one or more of the examples described above, the functions described in the present application can be implemented by hardware, software, firmware or any combination thereof. When implemented by software, the functions can be stored in a computer readable medium or transmitted as one or more instructions or codes on a computer readable medium.

[0138] The above detailed description of the specific embodiments of the present application further explains the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made on the basis of the technical solutions of the present application should be included in the protection scope of the present application.

Claims

1. A method of assembling a profiled curved component in a helicopter, characterised in that, The method comprises the following steps: According to the edge features corresponding to the target accessory and the target skeleton to be assembled respectively, the planning scanning path for scanning the target accessory and the target skeleton is determined respectively; wherein the target accessory includes a special-shaped curved accessory; According to the planning scanning path, the target accessory and the target skeleton are scanned, and based on the obtained scanning results, the first model corresponding to the target accessory and the second model corresponding to the target skeleton are established; The first model and the second model are compared, and the contact stress distribution map when the target accessory and the target skeleton are assembled is predicted based on the comparison result; According to the contact stress distribution map, the target accessory is assembled to the target skeleton by using an assembly robot.

2. The method of claim 1, wherein, The method for obtaining the edge features comprises: A depth camera installed by the assembly robot is used to obtain photos corresponding to the target accessory and the target skeleton respectively; Based on the photos, a first initial model corresponding to the target accessory and a second initial model corresponding to the target skeleton are established; Feature analysis is performed on the first initial model and the second initial model to obtain the edge features corresponding to the target accessory and the target skeleton respectively.

3. The method of claim 2, wherein, The feature analysis on the first initial model and the second initial model to obtain the edge features corresponding to the target accessory and the target skeleton respectively comprises: Identify and mark each corner on the outer edge of the first initial model and the second initial model; The features of each corner marked in the first initial model are taken as the edge features corresponding to the target accessory, and the features of each corner marked in the second initial model are taken as the edge features corresponding to the target skeleton.

4. The method according to claim 1 or 3, characterized in that, According to the edge features corresponding to the target accessory and the target skeleton to be assembled respectively, the planning scanning path for scanning the target accessory and the target skeleton is determined respectively, which comprises: According to the edge features corresponding to the target accessory and the target skeleton to be assembled respectively, the position coordinates of the target accessory and the target skeleton relative to the assembly robot and the contour coordinates of the target accessory and the target skeleton are determined; Based on the position coordinates and the contour coordinates, the direction change and the position change of the 3D scanner used for scanning the target accessory and the target skeleton are determined; The direction change and the position change of the 3D scanner are determined as the planning scanning path for scanning the target accessory and the target skeleton.

5. The method of claim 4, wherein, According to the planning scanning path, the target accessory and the target skeleton are scanned, which comprises: For the direction change and the position change of the 3D scanner, the motion scheme of each joint of the mechanical arm clamping the 3D scanner is planned; Based on the motion scheme, the mechanical arm clamping the 3D scanner is controlled to scan the target accessory and the target skeleton; Based on the obtained scanning results, the first model corresponding to the target accessory and the second model corresponding to the target skeleton are established, which comprises: The motion trajectory formed after the 3D scanner is gripped by the mechanical arm to complete scanning and the plurality of scanning photos obtained by the 3D scanner are combined to establish a first model corresponding to the target accessory and a second model corresponding to the target skeleton.

6. The method of claim 1, wherein, Before the first model and the second model are compared, the method further comprises: For the first model and the second model, a defect position where contact stress exists when the first model and the second model are fitted to simulate the assembly of the target accessory and the target skeleton is determined, and a predicted contact stress corresponding to the defect position is determined; Obtain the geometric and positional errors of the defect positions, the geometric and positional errors including height errors and shape errors; According to the geometric and positional errors of the defect positions and the corresponding predicted contact stress, a mapping equation between the geometric and positional errors and the contact stress is established.

7. The method of claim 6, wherein, The determination of the defect position where contact stress exists when the first model and the second model are fitted to simulate the assembly of the target accessory and the target skeleton comprises: Each defect point and assembly hole in the first model and the second model is identified and marked; the defect point is a position of an abnormal protrusion and / or an abnormal depression carried by the target accessory and the target skeleton when they are shipped; For each defect position and assembly hole, the area feature, the gray scale feature and the gradient feature corresponding to the defect position and the assembly hole are calculated as the defect feature corresponding to the defect position and the assembly hole, respectively; Each defect point and assembly hole in the first model and the second model is compared, and based on the comparison result and the defect feature corresponding to each defect point and assembly hole, the geometric and positional error corresponding to each defect point and assembly hole is obtained; The defect point and / or assembly hole whose geometric and positional error meets a preset rule for generating contact stress is determined as the defect position.

8. The method of claim 6, wherein, According to the geometric and positional errors of the defect positions and the corresponding predicted contact stress, a mapping equation between the geometric and positional errors and the contact stress is established, comprising: For the first model, according to the geometric and positional errors of the defect positions and the corresponding predicted contact stress, in combination with the rigidity of the target accessory, the rigid body coordinates of the simulated contact points between the assembly robot and the first model, and the flexible body coordinates of each assembly hole on the first model relative to the simulated contact points, the mapping equation between the geometric and positional errors and the contact stress is established.

9. The method of claim 6, wherein, The first model and the second model are compared, and based on the comparison result, the contact stress distribution diagram when the target accessory and the target skeleton are assembled is predicted, comprising: According to the mounting direction of the target accessory to the target skeleton, the edges of the first model and the second model are compared and matched to obtain a chromatogram corresponding to the fitting of the first model and the second model, the chromatogram being used to represent the geometric and positional errors of each point on the edges of the first model and the second model; Based on the chromatogram and the mapping equation, the fitting of the first model and the second model is digitally simulated to predict the contact stress distribution diagram when the target accessory and the target skeleton are assembled.

10. An assembly device for a profiled curved component in a helicopter, characterized in that, Comprise: A planning unit is configured to determine a planned scanning path for scanning the target fitting and the target framework respectively according to the edge features corresponding to the target fitting and the target framework respectively, wherein the target fitting comprises a special-shaped curved surface. A modeling unit is configured to scan the target fitting and the target framework according to the planned scanning path, and establish a first model corresponding to the target fitting and a second model corresponding to the target framework based on the obtained scanning results. A prediction unit is configured to compare the first model and the second model, and predict a contact stress distribution map when the target fitting and the target framework are assembled based on the comparison result. An assembling unit is configured to assemble the target fitting to the target framework using an assembling robot according to the contact stress distribution map.

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