Engine attitude adjustment control method and engine lifting system

Abstract

The invention relates to an engine attitude adjusting control method and an engine lifting system. The engine control method comprises the steps that S1, initial positioning is conducted on the lifting positioner and the displacement sensor arranged on the lifting positioner, and the displacement sensor is calibrated and calibrated; s2, arranging calibration blocks on an engine mounting system and an aircraft hanging bracket, scanning position environments of the engine mounting system and the aircraft hanging bracket by a laser radar, and generating a corresponding initial three-dimensional point cloud picture; s3, establishing a virtual coordinate system, and calibrating initial positions of an engine mounting system and an aircraft hanging bracket; and S4, the lifting path of the engine is calculated based on the initial position. According to the engine posture adjusting control method and the engine lifting system, on-wing hair changing can be effectively achieved, on-wing hair changing can be effectively achieved, and the hair changing accuracy and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft engine replacement operation, and in particular to an engine attitude adjustment control method and an engine lifting system. Background Art

[0002] In the field of aviation engines, in order to ensure the continued airworthiness and safe operation of aircraft, when an engine fails or reaches restricted use conditions, it is necessary to carry out on-wing engine replacement. Due to the large weight and volume of the engine, complex external layout, and small installation space, the engine replacement cycle is long and difficult.

[0003] In the existing technology, on-wing engine replacement requires the use of guiding tools, including thorn chains, tension scales and other tools, and the engine is raised and lowered by tightening or loosening the thorn chains with a wrench. According to research, it usually takes 8 people more than 6 hours to complete the on-wing engine replacement of an engine. The on-wing engine replacement process is highly dependent on the operator, has low work efficiency, poor reliability, and poses safety hazards. Summary of the invention

[0004] In view of the above problems in the prior art, the present invention proposes an engine attitude control method and an engine lifting system, which can effectively realize on-wing engine replacement and improve the accuracy and efficiency of engine replacement.

[0005] Specifically, the present invention proposes an engine attitude control method, which is applicable to on-wing engine replacement, comprising the steps of:

[0006] S1, initially positioning a lifting positioner and a displacement sensor disposed thereon, and calibrating and calibrating the displacement sensor, wherein the lifting positioner is used to lift the engine to adjust the engine posture;

[0007] S2, arranging calibration blocks on the engine mounting system and the aircraft hanger, and scanning the position environment of the engine mounting system and the aircraft hanger by a laser radar to generate a corresponding initial three-dimensional point cloud map;

[0008] S3, establishing a virtual coordinate system, and calibrating the initial positions of the engine mounting system and the aircraft hanger on the virtual coordinate system according to the initial three-dimensional point cloud image;

[0009] S4, calculating the lifting path of the engine based on the initial position, controlling the lifting positioner to lift the engine to a specified position according to the lifting path, and during the lifting process, the laser radar continuously scans the position environment of the engine mounting system and the aircraft hanger, updates the three-dimensional point cloud map, and synchronously updates the lifting path based on the virtual coordinate system.

[0010] According to one embodiment of the present invention, the aircraft hanger includes an aircraft hanger and a nacelle cover connected to both sides of the bottom of the aircraft hanger, and the mounting system includes an engine process part and a front mounting section and a rear mounting section arranged on the top of the engine process part;

[0011] In step S2, a first calibration block is arranged on the aircraft hanger and the nacelle cover, a second calibration block is arranged on the front mounting section and the rear mounting section, a laser radar is arranged on the top of each of the front mounting section and the rear mounting section, and the laser radar scans the location environment of the mounting system and the aircraft hanger based on the first calibration block and the second calibration block.

[0012] According to one embodiment of the present invention, at least three of the first calibration blocks are arranged at each of the two connection areas where the bottom of the aircraft pylon is aligned with the front mounting section and the rear mounting section, and at least nine of the first calibration blocks are arranged on the inner skin of each nacelle cover;

[0013] At least two of the second calibration blocks are arranged on the top of the front installation section and the top of the rear installation section.

[0014] According to one embodiment of the present invention, the nine first calibration blocks are divided into three groups, three in each group, and the three groups of first calibration blocks are evenly distributed on the inner skin of each nacelle cover according to a set rotation angle α, and 30°≤rotation angle α≤70°.

[0015] According to one embodiment of the present invention, in step S2, the process of generating an initial three-dimensional point cloud image includes:

[0016] Based on stereo vision technology and image processing technology, the left and right binocular vision images are calibrated and matched; a stereo vision matching algorithm is used to complete the mapping from image coordinates to actual coordinates; the area of ​​the marked area and the spatial coordinates of the feature points are calculated to achieve three-dimensional measurement and stereo reconstruction of the installation system and the aircraft hanger surface calibration block.

[0017] According to one embodiment of the present invention, in step S4, the optimized point cloud image is calculated by the KF-SLAM algorithm, including the steps of:

[0018] S41, determining the initial position and attitude information of the engine according to the first calibration block and the second calibration block on the aircraft hanging and mounting system, which is counted as a data set M0;

[0019] S42, engine attitude measurement, based on the initial position and attitude information of the engine, the displacement data obtained by the displacement sensor on the lift positioner is used to calculate the theoretical position and attitude information of the engine, and the data set M1 is calculated;

[0020] S43, based on the real-time scanning of the first calibration block and the second calibration block by the laser radar, obtain the position information of the installation system and the aircraft suspension, calculate the real-time position and attitude information of the engine, and count it as the data set M2;

[0021] S44, compare and analyze the data sets M1 and M2. If the data set setting conditions are met, associate the data sets M0, M1, and M2, continuously update the three-dimensional point cloud map, and calculate and update the lifting path.

[0022] According to one embodiment of the present invention, the data set setting condition is: |M1-M2|<10%×min{M1, M2}. If it is satisfied, the lifting positioner is controlled to lift the engine to a specified position. If it is not satisfied, the lifting operation is stopped.

[0023] The present invention also provides an engine lifting system, which is applicable to the above-mentioned engine attitude adjustment control method, comprising:

[0024] An engine lifting device comprises a mounting bracket, four lifting positioners and four process adapters, wherein the mounting bracket is used to carry the engine, the four lifting positioners include a main lifting positioner and three auxiliary lifting positioners, which are respectively arranged at a corner of the mounting bracket, each lifting positioner is connected to the mounting bracket through one process adapter, and each lifting positioner can move on the X / Y / Z axis of the engine to drive the engine to generate displacement through the process adapter;

[0025] A sensor group, including a force sensor and a displacement sensor, wherein one force sensor is arranged on each of the lifting positioners to obtain the pulling force of the lifting positioner driving the process adapter, and a plurality of displacement sensors are arranged on each of the lifting positioners to detect the displacement of the lifting positioner on the X / Y / Z axis of the engine;

[0026] An electronic control unit is arranged in the lifting main positioner, and the electronic control unit includes a data acquisition control module and a calculation module. The data acquisition control module is used to receive the detection signal obtained by the sensor group and the laser radar scanning signal. The calculation module generates an initial three-dimensional point cloud map based on the scanning signal, and establishes a virtual coordinate system. The initial positions of the engine mounting system and the aircraft hanger are calibrated on the initial three-dimensional point cloud map. The calculation module calculates the lifting path of the engine based on the initial position. The electronic control unit realizes 6-degree-of-freedom adjustment of the engine's spatial posture through the differential of four lifting positioners based on the lifting path; wherein, during the lifting process, the data acquisition control module continuously receives the detection signal and the scanning signal, and the calculation module continuously updates the three-dimensional point cloud map based on the detection signal and the scanning signal, and synchronously calculates the lifting path based on the virtual coordinate system.

[0027] According to an embodiment of the present invention, the signal of the displacement sensor received by the data acquisition control module should meet the displacement setting condition, multiple displacement sensors are arranged on each of the lift positioners, and two displacement sensors are arranged in any axis direction of the X / Y / Z axis of the engine to detect the displacement of the lift positioner on the axis, and the displacement signals obtained are P1 and P2;

[0028] The displacement setting conditions are:

[0029] If the P1 and P2 signals are normal and satisfy |P1-P2|<10%×min{P1, P2}, the mean value P3 of the signal is used as the displacement value of the axis, P3=(P1+P2) / 2;

[0030] If one of the signals in P1 or P2 is normal, the normal signal is used as the displacement value of the axis;

[0031] If the P1 and P2 signals are normal and |P1-P2|≥10%×min{P1, P2}, the displacement sensor needs to be calibrated;

[0032] If both P1 and P2 signals are abnormal, the corresponding displacement sensor needs to be replaced and calibrated.

[0033] According to an embodiment of the present invention, the signal of the force sensor received by the data acquisition control module should meet the tension setting condition. Assuming that the four tension signals are F1, F2, F3, and F4, the tension setting condition is:

[0034] If max{F1, F2, F3, F4}-min{F1, F2, F3, F4}<10%×min{F1, F2, F3, F4}, it means that the tension signal is normal;

[0035] If max{F1, F2, F3, F4}-min{F1, F2, F3, F4}≥10%×min{F1, F2, F3, F4}, the electronic control unit or the data acquisition control module triggers a safety alarm.

[0036] According to one embodiment of the present invention, each of the lifting positioners comprises:

[0037] A base module, comprising a base assembly, a first slide rail, a first motor and a motor fixing plate, wherein the first slide rail is fixedly arranged on the base assembly, the first motor is fixed on the motor fixing plate, and the first motor is used to drive the motor fixing plate to move along the first slide rail;

[0038] A ram module, comprising a mounting plate assembly, a ram moving assembly, a second slide rail, a second motor and a flexible connector, wherein the second slide rail is fixed to the ram moving assembly, the second motor is fixed to the mounting plate assembly, the second motor is used to drive the ram moving assembly to move along the length direction of the second slide rail, one end of the flexible connector is connected and fixed to the ram moving assembly, and the other end is connected and fixed to the process adapter;

[0039] The column module comprises a column assembly, a third slide rail, a third motor and a ball screw, wherein the bottom of the column assembly is fixed to the motor fixing plate, the ball screw cooperates with the mounting plate assembly, and the third motor is used to drive the ball screw to rotate, thereby driving the entire slide module to move along the length direction of the third slide rail through the mounting plate assembly;

[0040] The length directions of the first slide rail, the second slide rail and the third slide rail correspond to the X direction, the Y direction and the Z direction of the engine.

[0041] According to one embodiment of the present invention, the calculation module solves the specified posture of the engine corresponding to the lifting path, decomposes the spatial position and posture of the specified posture into the movement stroke of each lifting positioner in the X / Y / Z axis direction, and synchronously drives the lifting positioner linkage through the electronic control unit to make the engine reach the specified posture.

[0042] According to one embodiment of the present invention, the lifting methods of the engine include single-point movement, linear movement and non-linear movement;

[0043] The single-point movement means that the electronic control unit controls a certain lifting positioner to move along the X-axis, Y-axis or Z-axis according to actual needs;

[0044] The linear movement means that the electronic control unit performs linear synchronous control on the three lifting auxiliary positioners and the lifting main positioner, and the three-axis movement of the three lifting auxiliary positioners is synchronized with the three-axis movement of the lifting main positioner in a linear relationship so that the engine reaches the specified position at the set time;

[0045] The nonlinear movement means that the electronic control unit performs nonlinear synchronous control on the three lifting auxiliary positioners and the lifting main positioner, and the three-axis movement of the three lifting auxiliary positioners is synchronized with the three-axis movement of the lifting main positioner according to a nonlinear relationship so that the engine reaches the specified position at a set time;

[0046] The electronic control unit calculates nonlinear movement parameters, and the electronic control unit uses the nonlinear movement parameters to control the actions of the four lifting positioners. The nonlinear movement parameters are calculated according to the cam coupling quintuplets, and the formulas for calculating position, velocity and acceleration are:

[0047] Position: f(x)=a0+a1×x+a2×x^2+a3×x^3+a4×x^4+a5×x^5;

[0048] Speed: f'(x) = a1 + 2 × a2 × x + 3 × a3 × x^2 + 4 × a4 × x^3 + 5 × a5 × x^4;

[0049] Acceleration: f”(x) = 2×a2+6×a3×x+12×a4×x^2+20×a5×x^3;

[0050] Among them, x is time, f(x) is the position of a certain axis at a certain point in time, velocity is the first-order derivative, acceleration is the second-order derivative, and a0~a5 are nonlinear movement parameters.

[0051] An engine attitude control method and an engine lifting system provided by the present invention apply LiDAR SLAM to the on-wing engine replacement process of aircraft engines, supplement the traditional positioning system composed of displacement sensors and force sensors in the on-wing engine replacement process, and simultaneously estimate the position and posture of the engine, the three-dimensional point cloud map of the aircraft suspension and the nacelle cover in the on-wing engine replacement process, and construct the movement path of the engine in the on-wing engine replacement process through LiDAR SLAM, thereby improving the positioning accuracy of the on-wing engine replacement process, and improving the safety and overall efficiency of the on-wing engine replacement process.

[0052] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as described. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this application. The accompanying drawings illustrate embodiments of the present invention and together with the description serve to explain the principle of the present invention.

[0054] In the attached figure:

[0055] Figure 1 A flowchart of an engine attitude adjustment control method according to an embodiment of the present invention is shown.

[0056] Figure 2 A schematic diagram showing the structure of an aircraft hanger and a mounting system according to an embodiment of the present invention Figure 1 .

[0057] Figure 3 A schematic diagram showing the structure of an aircraft hanger and a mounting system according to an embodiment of the present invention Figure 2 .

[0058] Figure 4 A schematic diagram showing a structure in which a first calibration block is arranged on a nacelle cover according to an embodiment of the present invention Figure 1 .

[0059] Figure 5 A schematic diagram showing a structure in which a first calibration block is arranged on a nacelle cover according to an embodiment of the present invention Figure 2 .

[0060] Figure 6 A schematic structural diagram showing a second calibration block arranged on the front and rear mounting sections according to an embodiment of the present invention is shown.

[0061] Figure 7 A schematic structural diagram of an engine lifting system according to an embodiment of the present invention is shown.

[0062] Figure 8 A schematic structural diagram of a lifting positioner according to an embodiment of the present invention is shown.

[0063] Fig. 9 A cross-sectional view of a lift positioner according to one embodiment of the present invention is shown.

[0064] Fig.10 A schematic diagram showing the structure of a base module of a lifting positioner according to an embodiment of the present invention Figure 1 .

[0065] Fig.11 A schematic diagram showing the structure of a base module of a lifting positioner according to an embodiment of the present invention Figure 2 .

[0066] Fig.12 A schematic diagram showing the structure of a ram module of a lift positioner according to an embodiment of the present invention Figure 1 .

[0067] Fig.13 A schematic diagram showing the structure of a ram module of a lift positioner according to an embodiment of the present invention Figure 2 .

[0068] Fig.14 A schematic structural diagram of a column module of a lifting positioner according to an embodiment of the present invention is shown.

[0069] Fig.15 This is a schematic diagram of the stereoscopic vision principle.

[0070] The above drawings include the following reference numerals:

[0071] Aircraft hanging 501

[0072] Nacelle cover 502

[0073] Engine Process Parts 503

[0074] Front installation section 504

[0075] Rear installation section 505

[0076] First calibration block 506

[0077] The second calibration block 507

[0078] LiDAR 508

[0079] Connecting area 509

[0080] Engine Lift System 100

[0081] Mounting bracket 101

[0082] Lifting positioner 102

[0083] Lifting master positioner 1021

[0084] Lifting auxiliary positioner 1022

[0085] Process adapter 103

[0086] Base module 200

[0087] Base assembly 201

[0088] First slide rail 202

[0089] The first motor 203

[0090] Motor fixing plate 204

[0091] First meshing rack 205

[0092] First slider 206

[0093] Moving wheel 207

[0094] The first limit block 208

[0095] The first displacement sensor 209

[0096] Ram module 300

[0097] Mounting plate assembly 301

[0098] First horizontal board 3011

[0099] Second horizontal board 3012

[0100] Vertical board 3013

[0101] Ram moving assembly 302

[0102] Second slide rail 303

[0103] The second motor 304

[0104] Flexible connector 305

[0105] Second meshing rack 306

[0106] Second slider 307

[0107] The second limit block 308

[0108] The second displacement sensor 309

[0109] Screw limit block 310

[0110] Force Sensor 311

[0111] Column module 400

[0112] Column assembly 401

[0113] The third slide rail 402

[0114] The third motor 403

[0115] Ball Screw 404

[0116] The third slider 405

[0117] Bearing 406

[0118] The third displacement sensor 407

[0119] The third limit block 408 DETAILED DESCRIPTION

[0120] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0121] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually merely illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0122] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0123] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0124] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0125] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways, rotated 90 degrees or in other orientations, and the spatially relative descriptions used herein are interpreted accordingly.

[0126] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0127] Figure 1 A flowchart of an engine attitude control method according to an embodiment of the present invention is shown. As shown in the figure, an engine attitude control method suitable for on-wing engine replacement includes the following steps:

[0128] S1, initially positioning the lifting positioner and the displacement sensor disposed thereon, calibrating and calibrating the displacement sensor, the lifting positioner is used to lift the engine to adjust the engine posture;

[0129] S2, arranging calibration blocks on the engine mounting system and the aircraft hanger, scanning the position environment of the engine mounting system and the aircraft hanger based on the calibration block laser radar, and generating a corresponding initial three-dimensional point cloud map;

[0130] S3, establishing a virtual coordinate system, and calibrating the initial positions of the engine mounting system and the aircraft hanger on the virtual coordinate system according to the initial three-dimensional point cloud image;

[0131] S4, calculates the lifting path of the engine based on the initial position, controls the lifting positioner to lift the engine to the specified position according to the lifting path, and during the lifting process, the laser radar continuously scans the position environment of the engine installation system and the aircraft hanger, updates the three-dimensional point cloud map, and synchronously updates the lifting path based on the virtual coordinate system.

[0132] Figure 2 A schematic diagram showing the structure of an aircraft hanger and a mounting system according to an embodiment of the present invention Figure 1 . Figure 3 A schematic diagram showing the structure of an aircraft hanger and a mounting system according to an embodiment of the present invention Figure 2 . Figure 4 A schematic diagram showing a structure in which a first calibration block is arranged on a nacelle cover according to an embodiment of the present invention Figure 1 . Figure 5 A schematic diagram showing a structure in which a first calibration block is arranged on a nacelle cover according to an embodiment of the present invention Figure 2 . Figure 6The schematic diagram of the structure in which the second calibration block is arranged on the front and rear mounting sections of one embodiment of the present invention is shown. As shown in the figure, the aircraft hanger includes an aircraft hanger 501 and a nacelle cover 502 connected to both sides of the bottom of the aircraft hanger 501, and the mounting system includes an engine process part 503 and a front mounting section 504 and a rear mounting section 505 arranged on the top of the engine process part 503. The mounting system is installed on the engine, and the ultimate purpose of lifting the engine is to dock the mounting system with the aircraft hanger so that the engine is suspended to the bottom of the aircraft hanger, that is, to dock the front mounting section 504 and the rear mounting section 505 upward to the bottom of the aircraft hanger 501. Therefore, during the lifting process of the engine, the engine needs to be controlled for attitude adjustment.

[0133] In step S2, a first calibration block 506 is arranged on the aircraft pylon 501 and the nacelle cover 502, and a second calibration block 507 is arranged on the front mounting section 504 and the rear mounting section 505. A laser radar 508 is arranged on the top of each of the front mounting section 504 and the rear mounting section 505. The laser radar 508 scans the location environment of the mounting system and the aircraft pylon based on the first calibration block 506 and the second calibration block 507 to generate a corresponding initial three-dimensional point cloud map. For easy identification, the shape of the first calibration block 506 and the second calibration block 507 is preferably a cube, a cylinder or a cuboid.

[0134] Preferably, reference Figure 5 At least three first calibration blocks 506 are arranged at each of the two connection areas 509 at the bottom of the aircraft suspension 501 and aligned with the front installation section 504 and the rear installation section 505, and at least nine first calibration blocks 506 are arranged on the inner skin of each nacelle cover 502. Figure 6 At least two second calibration blocks 507 are arranged on the top of the front installation section 504 and the rear installation section 505. A certain number of calibration blocks are arranged in order to obtain a more accurate three-dimensional point cloud map and ensure the accuracy of the subsequent calculation of the lifting path.

[0135] Preferably, reference Figure 4 and Figure 5 , the 9 first calibration blocks 506 arranged on the nacelle cover 502 are divided into 3 groups, each with 3. On the inner skin of each nacelle cover 502, 3 groups of first calibration blocks 506 are evenly distributed according to the set rotation angle α. Figure 4 As shown, a group of first calibration blocks 506 are arranged at the bottom of the inner skin of the nacelle cover 502, and then another group of first calibration blocks 506 are arranged upward at intervals of a set angle α. The last group of first calibration blocks 506 are arranged upward at intervals of a set angle α. Figure 5 Each group of three first calibration blocks 506 is arranged along the X-axis of the engine and is evenly distributed over the axial length of the nacelle cover 502. The rotation angle α is preferably: 30°≤rotation angle α≤70°.

[0136] In step S2, the process of generating the initial three-dimensional point cloud includes: completing the calibration and matching of the left and right binocular vision images based on stereo vision technology and image processing technology; using stereo vision matching algorithm to complete the mapping from image coordinates to actual coordinates; calculating the area of ​​the marked area and the spatial coordinates of the feature points, and realizing the three-dimensional measurement and stereo reconstruction of the calibration block (position / calibration area) on the surface of the installation system and the aircraft hanger. Specifically, it is to use laser radar to scan the physical object itself, based on the damage image parameters of the image coordinate system, and use the stereo matching algorithm to combine the image coordinates of the image parameters with the actual physical coordinates of the image parameters to realize the three-dimensional reconstruction of the solid surface.

[0137] Stereo matching is the most important step in the parallax ranging process and is also the most difficult problem in stereo vision. When a spatial three-dimensional scene is projected into a two-dimensional image, the image of the same scene from different viewpoints will be very different. In addition, many factors such as the lighting conditions, noise interference and distortion in the scene, and camera characteristics are integrated into a single value of the grayscale in the image. At the same time, the previous preprocessing process may cause further distortion of the pixels. Therefore, it is difficult to perform unambiguous and high-accuracy stereo matching of images.

[0138] Common matching algorithms include correlation algorithm, relaxation algorithm, polyhedron correspondence algorithm and three-camera system correspondence algorithm. The laser radar 508 at the same position can emit two light beams, and perform virtual stereo reconstruction of the solid surface based on the principle of stereo vision. The calibration block (position) on the nacelle cover and aircraft suspension can be scanned and calculated and analyzed. The preferred algorithm example is as follows:

[0139] Fig.15 This is a schematic diagram of the stereoscopic vision principle. As shown in the figure, according to the depth calculation principle of stereoscopic vision, when the coordinate system is fixed at the optical center of the camera, we have:

[0140]

[0141] The two-dimensional coordinate information is converted into three-dimensional coordinate information. Among them: (X, Y, Z) is the coordinate of the object point; (u1, v1) and (u2, v2) are the coordinates of the corresponding points of the object point on the left and right image planes; D = (u1-u2) is the parallax. For two points M and N with a certain distance L in space, their image points can be found on the left and right image planes by matching. When the focal length f is determined, the baseline distance b can be calculated.

[0142]

[0143] M, N actual measurement points, determine key parameters

[0144] To convert the previously calculated image coordinate system into a physical coordinate system, the following formula can be used:

[0145]

[0146] Among them: u, v are the coordinates in the image coordinate system, in pixels; x, y are the physical coordinates in mm; u0, v0 are the pixel coordinates at the intersection of the camera optical axis and the image plane, and this point is taken as the center of the adjusted image in the system; dx, dy are the scale factors of the axes, which can be obtained by measurement.

[0147] After the coordinate system is established, the coordinates of the image midpoint and the imaging point need to be compared and measured to calculate the matching degree. L Take a point in (x, y) as the center and a template T of size mxn. Suppose that it moves △x in the horizontal direction and △y in the vertical direction, the f it covers R The kth subgraph of (x,y) is S k , if T and S k The same, then their difference is 0. Define T and S k The measure of the difference between is:

[0148]

[0149] The coordinates of the midpoint of the image are compared and measured with the imaging point to calculate the degree of matching.

[0150] When D(T,S k ) is minimum, T and S k To achieve the best match, the normalized cross-correlation function is defined as:

[0151]

[0152] When C(△x,△y) reaches the maximum, it means that the image point matches the imaging point.

[0153] Preferably, in step S4, the optimized point cloud map is calculated by KF-SLAM (Kalman Filter, Kalman Filter-Simultaneous Localization and Mapping) algorithm, including the steps of:

[0154] S41, determining the initial position and attitude information of the engine according to the first calibration block 506 and the second calibration block 507 on the aircraft suspension 501 and the installation system, which is counted as a data set M0;

[0155] S42, engine attitude measurement, based on the initial position and attitude information of the engine, the displacement data obtained by the displacement sensor on the lifting positioner is used to calculate the theoretical position and attitude information of the engine, and the data set M1 is calculated. It should be noted that during the engine lifting process, the displacement data is continuously obtained to calculate the theoretical position and attitude information of the engine.

[0156] S43, based on the real-time scanning of the laser radar 508, the first calibration block 506 and the second calibration block 507 are used to obtain the position information of the installation system and the aircraft pylon 501, and the real-time position and attitude information of the engine are calculated, which is counted as data set M2. Similarly, during the engine lifting process, the first calibration block 506 and the second calibration block 507 are continuously scanned to obtain the position information of the installation system and the aircraft pylon 501, and the real-time position and attitude information of the engine are calculated and updated.

[0157] S44, compare and analyze the data sets M1 and M2. If the data set setting conditions are met, associate the data sets M0, M1, and M2, continuously update the three-dimensional point cloud map, and calculate and update the lifting path.

[0158] The laser radar KF-SLAM is applied to the on-wing engine replacement process of aircraft engines to form a visual laser-assisted positioning, which can supplement the traditional positioning system composed of displacement sensors and the like in the on-wing engine replacement process. At the same time, the posture of the engine, the three-dimensional point cloud map of the aircraft suspension 501 and the nacelle cover 502 in the on-wing engine replacement process are estimated, and the movement path (lifting path) of the engine in the on-wing engine replacement process is constructed through the laser radar KF-SLAM, which can improve the positioning accuracy of the on-wing engine replacement process and improve the safety of the on-wing engine replacement process.

[0159] Preferably, in step S44, the data set setting condition is: |M1-M2|<10%×min{M1, M2}. If it is satisfied, it means that the data is normal, and the lifting positioner is controlled to lift the engine to the specified position. If it is not satisfied, it means that the data is abnormal, the lifting operation is stopped, and components such as sensors and lidar need to be checked.

[0160] Figure 7 A schematic structural diagram of an engine lifting system according to an embodiment of the present invention is shown. Figure 8 A schematic structural diagram of a lifting positioner according to an embodiment of the present invention is shown. Fig. 9 A cross-sectional view of a lift positioner according to an embodiment of the present invention is shown. Figure 7An engine lifting system 100 suitable for the aforementioned engine attitude control method includes a mounting bracket 101, four lifting positioners 102 and four process adapters 103. Among them, the mounting bracket 101 is used to carry the engine, and the four lifting positioners 102 include a lifting main positioner 1021 and three lifting auxiliary positioners 1022, which are respectively arranged at a corner of the mounting bracket 101. Each lifting positioner 102 is connected to the mounting bracket 101 through a process adapter 103. Each lifting positioner 102 can move in the X / Y / Z axis direction of the engine to drive the engine to produce displacement through the process adapter 103.

[0161] Furthermore, the engine lifting system 100 also includes a sensor group. The sensor group includes a force sensor and a displacement sensor. A force sensor is arranged on each lifting positioner 102 to obtain the pulling force of the lifting positioner 102 driving the process adapter 103. A plurality of displacement sensors are arranged on each lifting positioner 102 to detect the displacement of the lifting positioner in the X / Y / Z axis direction of the engine.

[0162] The engine lifting system 100 also includes an electronic control unit (not shown in the figure). The electronic control unit is arranged on the lifting main positioner 1021. The electronic control unit includes a data acquisition control module and a calculation module. The data acquisition control module is used to receive the detection signal and the laser radar scanning signal obtained by the sensor group. The calculation module generates an initial three-dimensional point cloud map based on the scanning signal, and establishes a virtual coordinate system, calibrates the initial position of the engine mounting system and the aircraft hanger on the initial three-dimensional point cloud map, and the calculation module calculates the lifting path of the engine based on the initial position. The electronic control unit realizes the 6-degree-of-freedom adjustment of the engine in the space posture through the differential of the four lifting positioners 102 based on the lifting path. Specifically, the calculation module calculates the output power of each lifting positioner 102 according to the lifting path, and the electronic control unit controls each lifting positioner 102 to act synchronously according to the output power. In the lifting process, the data acquisition control module continuously receives the detection signal and the scanning signal, and the calculation module continuously updates the three-dimensional point cloud map based on the detection signal and the scanning signal, and synchronously calculates the lifting path based on the virtual coordinate system.

[0163] Preferably, the signal of the displacement sensor received by the data acquisition control module should meet the displacement setting conditions, multiple displacement sensors are arranged on each lifting positioner 102, and two displacement sensors are arranged in any axis direction of the X / Y / Z axis of the engine to detect the displacement of the lifting positioner 102 on the axis, and the displacement signals obtained are P1 and P2. The displacement setting conditions are:

[0164] If the P1 and P2 signals are normal and satisfy |P1-P2|<10%×min{P1,P2}, the mean value P3 of the signal is used as the displacement value of the axis, P3=(P1+P2) / 2;

[0165] If one of the signals P1 or P2 is normal, the normal signal P1 or P2 is used as the displacement value of the axis;

[0166] If the P1 and P2 signals are normal and |P1-P2|≥10%×min{P1, P2}, the displacement sensor needs to be calibrated;

[0167] If both P1 and P2 signals are abnormal, the corresponding displacement sensor needs to be replaced and calibrated.

[0168] According to the displacement setting conditions, the displacement sensor with measurement error is replaced or calibrated to ensure the lifting operation of the engine.

[0169] Preferably, the signal of the force sensor received by the data acquisition control module should meet the tension setting condition. Assuming that the four tension signals are F1, F2, F3, and F4, the tension setting condition is:

[0170] If max{F1, F2, F3, F4}-min{F1, F2, F3, F4}<10%×min{F1, F2, F3, F4}, it means that the tension signal is normal;

[0171] If max{F1, F2, F3, F4}-min{F1, F2, F3, F4}≥10%×min{F1, F2, F3, F4}, the electronic control unit or the data acquisition control module triggers a safety alarm.

[0172] According to the tension setting conditions, the four lifting positioners 102 are guaranteed to maintain a balanced tension during the lifting process to prevent the engine from turning over or tilting.

[0173] Preferably, reference Figure 8 and Fig. 9 Each lift positioner 102 includes a base module 200 , a ram module 300 and a column module 400 .

[0174] Fig.10 A schematic diagram showing the structure of a base module of a lifting positioner according to an embodiment of the present invention Figure 1 . Fig.11 A schematic diagram showing the structure of a base module of a lifting positioner according to an embodiment of the present invention Figure 2As shown in the figure, the base module 200 includes a base assembly 201, a first slide rail 202, a first motor 203 and a motor fixing plate 204. The first slide rail 202 is fixedly arranged on the base assembly 201. The first motor 203 is fixed on the motor fixing plate 204. The first motor 203 is used to drive the motor fixing plate 204 to move along the first slide rail 202. It should be noted that Fig.11 The motor fixing plate 204 is removed to facilitate observation of the internal structure.

[0175] Fig.12 A schematic diagram showing the structure of a ram module of a lift positioner according to an embodiment of the present invention Figure 1 . Fig.13 A schematic diagram showing the structure of a ram module of a lift positioner according to an embodiment of the present invention Figure 2 As shown in the figure, the ram module 300 includes a mounting plate assembly 301, a ram moving assembly 302, a second slide rail 303, a second motor 304 and a flexible connector 305. The second slide rail 303 is fixed to the ram moving assembly 302. The second motor 304 is fixed to the mounting plate assembly 301. The second motor 304 is used to drive the ram moving assembly 302 to move along the length direction of the second slide rail 303. One end of the flexible connector 305 is connected and fixed to the ram moving assembly 302, and the other end is connected and fixed to the process adapter 103.

[0176] Fig.14 The structure diagram of the column module of the lifting positioner according to one embodiment of the present invention is shown. Fig. 9 As shown, the column module 400 includes a column assembly 401, a third slide rail 402 in the vertical direction, a third motor 403 and a ball screw 404. The bottom of the column assembly 401 is fixed on the motor fixing plate 204, that is, the entire column module 400 can move on the first slide rail 202 following the motor fixing plate 204. The ball screw 404 is arranged in the vertical direction and is threadedly matched with the mounting plate assembly 301. The third motor 403 is used to drive the ball screw 404 to rotate, and the ball screw 404 drives the entire ram module 300 to move along the length direction of the third slide rail 402 through the mounting plate assembly 301.

[0177] The length directions of the first slide rail 202, the second slide rail 303 and the third slide rail 402 correspond to the X direction, Y direction and Z direction of the engine. The heading of the aircraft is the X direction of the coordinate system, the vertical direction of the aircraft is the Y direction of the coordinate system, and the span direction of the aircraft is the Z direction of the coordinate system, which is consistent with the X / Y / X axis direction of the engine. It is easy to understand that the lifting positioner 102 controls the ram moving assembly 302 in the ram module 300 to move in the X / Y / X axis direction through the first motor 203, the second motor 304 and the third motor 403. The flexible connector 305 is used to connect the ram moving assembly 302 and the process adapter 103. Therefore, the lifting positioner 102 can cause the process adapter 103 to be displaced through the ram moving assembly 302, and the synchronous operation of the four lifting positioners 102 can drive the engine set on the mounting bracket 101 to adjust the posture to reach the installation position. The movement of the lifting positioner 102 in the X / Y / X axis direction mentioned below means that the lifting positioner 102 controls the movement of the ram moving assembly 302 in the X / Y / X axis direction, thereby acting on the process adapter 103 through the flexible connector 305. Since the lifting positioner 102 is driven by a motor, it can replace the complicated method of manually tightening the thorn chain with a wrench to lift the engine in the prior art, which greatly saves manpower, improves the work efficiency of the on-wing engine replacement process, and reduces safety hazards.

[0178] Preferably, reference Fig.11 , the base module 200 also includes a first meshing rack 205 and a first slider 206. The first meshing rack 205 is fixedly arranged on the base assembly 201, and its length direction is consistent with the first slide rail 202. The first slider 206 is fixedly arranged on the motor fixing plate 204, and the first slider 206 is slidably matched with the first slide rail 202. The output end of the first motor 203 cooperates with the first meshing rack 205, and the first motor 203 is started. The first motor 203 moves along the length direction of the first meshing rack 205 under the action of the first meshing rack 205, and then drives the motor fixing plate 204 to move along the first slide rail 202 under the cooperation of the first slider 206 and the first slide rail 202. In this embodiment, two parallel first slide rails 202 and four first sliders 206 are arranged to ensure that the motor fixing plate 204 moves smoothly on the X axis. More preferably, a moving wheel 207 is provided on one side of the bottom of the base assembly 201 to facilitate moving the entire lifting positioner 102 to a designated location.

[0179] Preferably, the base module 200 further includes a first limit block 208 and a first displacement sensor 209 disposed on the base assembly 201. The first limit block 208 has an anti-collision sensor, and the first limit block 208 and the first displacement sensor 209 are combined to limit the displacement of the motor fixing plate 204 to prevent the column module 400 from colliding when displacing on the X-axis, and to prevent the engine from flipping or tilting, thereby affecting the lifting operation.

[0180] Preferably, reference Fig.12 and Fig.13 , the ram module 300 also includes a second meshing rack 306 and a second slider 307. The second meshing rack 306 is fixedly arranged on the bottom surface of the ram moving assembly 302. The second slider 307 is fixedly arranged on the mounting plate assembly 301, and the second slider 307 is slidably matched with the second slide rail 303. The output end of the second motor 304 is matched with the second meshing rack 306. When the second motor 304 is started, under the action of the meshing rack and the cooperation of the second slider 307 and the second slide rail 303, the ram moving assembly 302 can move in the Y-axis direction. Specifically, the mounting plate assembly 301 is riveted or welded into one by the first transverse plate 3011, the second transverse plate 3012 and the vertical plate 3013. The second motor 304 is arranged at the bottom of the second transverse plate 3012, and the second slider 307 is arranged on the bottom surface of the first transverse plate 3011. The ram moving assembly 302 is penetrated on the vertical plate 3013.

[0181] Preferably, the ram module 300 further includes a second limit block 308 disposed on the ram moving assembly 302, and a second displacement sensor 309 disposed on the mounting plate assembly 301. The second limit block 308 has an anti-collision sensor, and the second limit block 308 and the second displacement sensor 309 are combined to limit the displacement of the ram moving assembly 302 to prevent the ram moving assembly 302 from colliding when displacing on the Y axis, thereby preventing the engine from flipping or tilting, thereby affecting the lifting operation.

[0182] Preferably, the ram module 300 further includes a screw stopper 310 disposed on the ram moving assembly 302. The screw stopper 310 is a hollow structure, the outer side of which is fixedly connected to the mounting plate assembly 301, and the inner side of which penetrates the ball screw 404 and is threadedly engaged with the ball screw 404. The ball screw 404 drives the mounting plate assembly 301 and the ram moving assembly 302 to move along the length direction of the third slide rail 402 through the screw stopper 310.

[0183] Preferably, the ram module 300 further includes a force sensor 311, which is disposed on the flexible connector 305 and is used to detect the tension borne by the flexible connector 305. The flexible connector 305 can avoid the rigid connection between the ram moving assembly 302 and the process adapter 103, and the tension value (tension signal) is obtained through the force sensor 311 to ensure that the tension of the four flexible connectors 305 is balanced, that is, the tension setting conditions of the four tension signals mentioned above need to be met.

[0184] refer to Fig.13 and Fig. 9The column module 400 further includes a third slider 405 and a bearing 406. The third slider 405 is slidably matched with the third slide rail 402. The third slider 405 is fixed to the vertical plate 3013 of the mounting plate assembly 301. The ball screw 404 is fixed to the column assembly 401 through the bearing 406. The third slider 405 is slidably matched with the third slide rail 402 to ensure that the ram module 300 moves smoothly in the direction of the third slide rail 402.

[0185] Preferably, reference Figures 11 to 13 , the column module 400 also includes a third displacement sensor 407 and a third limit block 408. The third displacement sensor 407 is arranged on the column assembly 401, and the third limit block 408 is arranged on the mounting plate assembly 301. The third limit block 408 has an anti-collision sensor, and the third limit block 408 and the third displacement sensor 407 are combined to limit the displacement of the ram module 300 in the length direction of the third slide rail 402 to prevent the ram moving assembly 302 from colliding when it is displaced on the Z axis, avoiding the engine from flipping or tilting, thereby affecting the lifting operation. It should be noted that each lifting positioner 102 needs to be provided with two first limit blocks 208 and two first displacement sensors 209 in the X-axis direction, a second limit block 308 and two second displacement sensors 309 in the Y-axis direction, and two third limit blocks 408 and two third displacement sensors 407 in the Z-axis direction. The combination of the limit block and the displacement sensor is used to detect the displacement of the slide moving component 302 of the lifting positioner 102 in the X / Y / X axis direction. The displacement signal obtained should meet the above-mentioned displacement setting conditions.

[0186] It is easy to understand that the heading of the aircraft is the X direction of the coordinate system, the vertical direction of the aircraft is the Y direction of the coordinate system, the span direction of the aircraft is the Z direction of the coordinate system, the rotation around the X axis of the aircraft coordinate system is an angle of α, the rotation around the Y axis of the aircraft coordinate system is an angle of β, and the rotation around the Z axis of the aircraft coordinate system is an angle of γ. The electronic control unit realizes the 6-degree-of-freedom adjustment of the engine's spatial attitude through the differential of the four lifting positioners 102. The 6 degrees of freedom are the degrees of freedom of movement along the X / Y / Z axis and the degrees of freedom of rotation around the three axes. The attitude control of the engine is to solve the specified posture of the engine corresponding to the lifting path through the calculation module according to the Jacobian matrix conversion, and decompose the spatial position and posture of the specified posture into the motion stroke of each lifting positioner 102 on the X / Y / Z axis. The output power of each lifting positioner 102 is calculated by the calculation module according to the motion stroke, and the electronic control unit synchronously drives the lifting positioner 102 to link so that the engine reaches the specified posture.

[0187] Preferably, the lifting modes of the engine by the lifting positioner 102 include single-point movement, linear movement and non-linear movement, so as to achieve precise adjustment of the position and spatial posture of the engine.

[0188] Among them, single-point movement means that the electronic control unit controls a certain lifting positioner 102 to move along the X-axis, Y-axis or Z-axis according to actual needs. Single-point movement can include positioning operation, stop, emergency stop, brake release, reset zero point and other operations.

[0189] Linear movement refers to the electronic control unit performing linear synchronous control on the three lifting auxiliary positioners 1022 and the lifting main positioner 1021. The three-axis movement of the three lifting auxiliary positioners 1022 is synchronized with the three-axis movement of the lifting main positioner 1021 in a linear relationship so that the engine reaches the specified position at the set time.

[0190] Non-linear movement refers to the non-linear synchronous control of the three lifting auxiliary positioners 1022 and the lifting main positioner 1021 by the electronic control unit. The three-axis movement of the three lifting auxiliary positioners 1022 is synchronized with the three-axis movement of the lifting main positioner 1021 according to a non-linear relationship so that the engine reaches the specified position at the set time.

[0191] The calculation module calculates the nonlinear movement parameters, and the electronic control unit uses the nonlinear movement parameters to control the actions of the four lifting positioners 102. The nonlinear movement parameters (cam synchronization coefficient) are calculated according to the cam coupling quintuple formula, and the formula for calculating position, speed and acceleration is:

[0192] Position: f(x)=a0+a1×x+a2×x^2+a3×x^3+a4×x^4+a5×x^5;

[0193] Speed: f'(x)=a1+2×a2×x+3×a3×x^2+4×a4×x^3+5×a5×x^4;

[0194] Acceleration: f”(x) = 2×a2+6×a3×x+12×a4×x^2+20×a5×x^3;

[0195] Among them, x is time, f(x) is the position of a certain axis at a certain point in time, velocity is the first-order derivative, acceleration is the second-order derivative, and a0~a5 are the nonlinear motion parameters that need to be solved.

[0196] It will be apparent to those skilled in the art that various modifications and variations may be made to the above exemplary embodiments of the present invention without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention covers modifications and variations of the present invention that fall within the scope of the appended claims and their equivalent technical solutions.

Claims

1. An engine attitude control method, applicable to on-wing engine replacement, comprising the steps of: S1, initially positioning a lifting positioner and a displacement sensor disposed thereon, and calibrating and calibrating the displacement sensor, wherein the lifting positioner is used to lift the engine to adjust the engine posture; S2, arranging calibration blocks on the engine mounting system and the aircraft hanger, and scanning the position environment of the engine mounting system and the aircraft hanger by a laser radar to generate a corresponding initial three-dimensional point cloud map; S3, establishing a virtual coordinate system, and calibrating the initial positions of the engine mounting system and the aircraft hanger on the virtual coordinate system according to the initial three-dimensional point cloud image; S4, calculating the lifting path of the engine based on the initial position, controlling the lifting positioner to lift the engine to a specified position according to the lifting path, and during the lifting process, the laser radar continuously scans the position environment of the engine mounting system and the aircraft hanger, updates the three-dimensional point cloud map, and synchronously updates the lifting path based on the virtual coordinate system.

2. The engine attitude control method according to claim 1, characterized in that: The aircraft hanger includes an aircraft hanger and a nacelle cover connected to both sides of the bottom of the aircraft hanger, and the mounting system includes an engine process part and a front mounting section and a rear mounting section arranged on the top of the engine process part; In step S2, a first calibration block is arranged on the aircraft hanger and the nacelle cover, a second calibration block is arranged on the front mounting section and the rear mounting section, a laser radar is arranged on the top of each of the front mounting section and the rear mounting section, and the laser radar scans the location environment of the mounting system and the aircraft hanger based on the first calibration block and the second calibration block.

3. The engine attitude control method according to claim 2, characterized in that: At least three of the first calibration blocks are arranged at each of the two connection areas of the bottom of the aircraft suspension and the front mounting section and the rear mounting section, and at least nine of the first calibration blocks are arranged on the inner skin of each nacelle cover; At least two of the second calibration blocks are arranged on the top of the front installation section and the top of the rear installation section.

4. The engine attitude control method according to claim 3, characterized in that: The nine first calibration blocks are divided into three groups, with three blocks in each group. The three groups of the first calibration blocks are evenly distributed on the inner skin of each nacelle cover according to a set rotation angle α, and 30°≤rotation angle α≤70°.

5. The engine attitude control method according to claim 1, characterized in that: In step S2, the process of generating an initial three-dimensional point cloud image includes: Based on stereo vision technology and image processing technology, the left and right binocular vision images are calibrated and matched; a stereo vision matching algorithm is used to complete the mapping from image coordinates to actual coordinates; the area of ​​the marked area and the spatial coordinates of the feature points are calculated to achieve three-dimensional measurement and stereo reconstruction of the installation system and the aircraft hanger surface calibration block.

6. The engine attitude control method according to claim 1, characterized in that: In step S4, the optimized point cloud map is calculated by the KF-SLAM algorithm, including the following steps: S41, determining the initial position and attitude information of the engine according to the first calibration block and the second calibration block on the aircraft hanging and mounting system, which is counted as a data set M0; S42, engine attitude measurement, based on the initial position and attitude information of the engine, the displacement data obtained by the displacement sensor on the lift positioner is used to calculate the theoretical position and attitude information of the engine, and the data set M1 is calculated; S43, based on the real-time scanning of the first calibration block and the second calibration block by the laser radar, obtain the position information of the installation system and the aircraft suspension, calculate the real-time position and attitude information of the engine, and count it as the data set M2; S44, compare and analyze the data sets M1 and M2. If the data set setting conditions are met, associate the data sets M0, M1, and M2, continuously update the three-dimensional point cloud map, and calculate and update the lifting path.

7. The engine attitude control method according to claim 6, characterized in that: The data set setting condition is: |M1-M2|<10%×min{M1, M2}. If it is satisfied, the lifting positioner is controlled to lift the engine to a specified position. If it is not satisfied, the lifting operation is stopped.

8. An engine lifting system, applicable to the engine attitude control method according to any one of claims 1 to 7, characterized in that: include: An engine lifting device comprises a mounting bracket, four lifting positioners and four process adapters, wherein the mounting bracket is used to carry the engine, the four lifting positioners include a main lifting positioner and three auxiliary lifting positioners, which are respectively arranged at a corner of the mounting bracket, each lifting positioner is connected to the mounting bracket through one process adapter, and each lifting positioner can move on the X / Y / Z axis of the engine to drive the engine to generate displacement through the process adapter; A sensor group, including a force sensor and a displacement sensor, wherein one force sensor is arranged on each of the lifting positioners to obtain the pulling force of the lifting positioner driving the process adapter, and a plurality of displacement sensors are arranged on each of the lifting positioners to detect the displacement of the lifting positioner on the X / Y / Z axis of the engine; An electronic control unit is arranged in the lifting main positioner, and the electronic control unit includes a data acquisition control module and a calculation module. The data acquisition control module is used to receive the detection signal obtained by the sensor group and the laser radar scanning signal. The calculation module generates an initial three-dimensional point cloud map based on the scanning signal, and establishes a virtual coordinate system. The initial positions of the engine mounting system and the aircraft hanger are calibrated on the initial three-dimensional point cloud map. The calculation module calculates the lifting path of the engine based on the initial position. The electronic control unit realizes 6-degree-of-freedom adjustment of the engine's spatial posture through the differential of four lifting positioners based on the lifting path; wherein, during the lifting process, the data acquisition control module continuously receives the detection signal and the scanning signal, and the calculation module continuously updates the three-dimensional point cloud map based on the detection signal and the scanning signal, and synchronously calculates the lifting path based on the virtual coordinate system.

9. The engine lifting system according to claim 8, characterized in that: The signal of the displacement sensor received by the data acquisition control module should meet the displacement setting condition. A plurality of displacement sensors are arranged on each of the lift positioners, and two displacement sensors are arranged in any axis direction of the X / Y / Z axis of the engine to detect the displacement of the lift positioner on the axis, and the displacement signals obtained are P1 and P2. The displacement setting conditions are: If the P1 and P2 signals are normal and satisfy |P1-P2|<10%×min{P1, P2}, the mean value P3 of the signal is used as the displacement value of the axis, P3=(P1+P2) / 2; If one of the signals in P1 or P2 is normal, the normal signal is used as the displacement value of the axis; If the P1 and P2 signals are normal and |P1-P2|≥10%×min{P1, P2}, the displacement sensor needs to be calibrated; If both P1 and P2 signals are abnormal, the corresponding displacement sensor needs to be replaced and calibrated.

10. The engine lifting system according to claim 8, characterized in that: The signal of the force sensor received by the data acquisition control module should meet the tension setting conditions. Assuming that the four tension signals are F1, F2, F3, and F4, the tension setting conditions are: If max{F1, F2, F3, F4}-min{F1, F2, F3, F4}<10%×min{F1, F2, F3, F4}, it means that the tension signal is normal; If max{F1, F2, F3, F4}-min{F1, F2, F3, F4}≥10%×min{F1, F2, F3, F4}, the electronic control unit or the data acquisition control module triggers a safety alarm.

11. The engine lifting system according to claim 8, characterized in that: Each of the lift positioners comprises: A base module, comprising a base assembly, a first slide rail, a first motor and a motor fixing plate, wherein the first slide rail is fixedly arranged on the base assembly, the first motor is fixed on the motor fixing plate, and the first motor is used to drive the motor fixing plate to move along the first slide rail; A ram module, comprising a mounting plate assembly, a ram moving assembly, a second slide rail, a second motor and a flexible connector, wherein the second slide rail is fixed to the ram moving assembly, the second motor is fixed to the mounting plate assembly, the second motor is used to drive the ram moving assembly to move along the length direction of the second slide rail, one end of the flexible connector is connected and fixed to the ram moving assembly, and the other end is connected and fixed to the process adapter; The column module comprises a column assembly, a third slide rail, a third motor and a ball screw, wherein the bottom of the column assembly is fixed to the motor fixing plate, the ball screw cooperates with the mounting plate assembly, and the third motor is used to drive the ball screw to rotate, thereby driving the entire slide module to move along the length direction of the third slide rail through the mounting plate assembly; The length directions of the first slide rail, the second slide rail and the third slide rail correspond to the X direction, the Y direction and the Z direction of the engine.

12. The engine lifting system according to claim 8, characterized in that: The calculation module solves the specified posture of the engine corresponding to the lifting path, decomposes the spatial position and posture of the specified posture into the movement stroke of each lifting positioner in the X / Y / Z axis direction, and synchronously drives the lifting positioner linkage through the electronic control unit to make the engine reach the specified posture.

13. The engine attitude control method according to claim 12, characterized in that: The lifting modes of the engine include single-point movement, linear movement and non-linear movement; The single-point movement means that the electronic control unit controls a certain lifting positioner to move along the X-axis, Y-axis or Z-axis according to actual needs; The linear movement means that the electronic control unit performs linear synchronous control on the three lifting auxiliary positioners and the lifting main positioner, and the three-axis movement of the three lifting auxiliary positioners is synchronized with the three-axis movement of the lifting main positioner in a linear relationship so that the engine reaches the specified position at the set time; The nonlinear movement means that the electronic control unit performs nonlinear synchronous control on the three lifting auxiliary positioners and the lifting main positioner, and the three-axis movement of the three lifting auxiliary positioners is synchronized with the three-axis movement of the lifting main positioner according to a nonlinear relationship so that the engine reaches the specified position at a set time; The electronic control unit calculates nonlinear movement parameters, and the electronic control unit uses the nonlinear movement parameters to control the actions of the four lifting positioners. The nonlinear movement parameters are calculated according to the cam coupling quintuplets, and the formulas for calculating position, velocity and acceleration are: Position: f(x)=a0+a1×x+a2×x^2+a3×x^3+a4×x^4+a5×x^5; Speed: f'(x) = a1+2×a2×x+3×a3×x^2+4×a4×x^3+5×a5×^ x4； Acceleration: f”(x) = 2×a2+6×a3×x+12×a4×x^2+20×a5×x^3; Among them, x is time, f(x) is the position of a certain axis at a certain point in time, velocity is the first-order derivative, acceleration is the second-order derivative, and a0~a5 are nonlinear movement parameters.

Images