A cabin docking measurement method

Abstract

The present invention proposes a cabin docking measurement method. The method comprises: using a 2D laser displacement sensor to obtain 2D contour data of multiple points on the flanges of two cabins; identifying the spatial positions of multiple edge points on the flanges of the cabins to be docked based on the 2D contour data of the multiple points; calculating the spatial angle deviation of the end face of the cabin to be docked relative to the end face of the reference cabin based on the spatial positions of the multiple edge points; identifying and calculating other posture deviations of the cabin to be docked relative to the reference cabin based on the geometric shape of the cabin end face; and sending the measurement results to an actuator to complete the posture adjustment of the cabin to be docked. The method provided by the present invention is a non-contact measurement method that does not require human participation, improves the automation level of cabin docking, and solves the problems of low cabin docking efficiency and poor docking quality.

Description

Technical Field

[0001] The invention relates to the field of automatic cabin docking, and in particular to a cabin docking measurement method. Background Art

[0002] Cabin docking is an important part of aerospace manufacturing. The accuracy and stability of docking directly affect the overall performance. At present, the docking operation of cabins in China adopts manual methods, which has low docking efficiency and difficult to ensure quality. In cabin docking, the accuracy and efficiency of the relative posture measurement of the two cabins are the requirements and difficulties of this task. At present, there are four main measurement methods used in the field of cabin docking. The first type is the early three-coordinate measuring machine and articulated measuring arm products. These products are large in size and require manual movement of the probe to complete the measurement, which is difficult to meet the needs of automation; the second type is the laser tracker, which requires the use of a target. The laser tracker is used to collect the target position and calculate the cabin posture. The target needs to be manually arranged on the object to be measured in advance. This link reduces the efficiency of docking and is not convenient for on-site implementation; the third type is to use a binocular vision camera to complete the posture measurement with the help of a target. The fourth type is to use a laser displacement sensor combined with a CCD camera to scan the outer contour surface of the cabin to fit the circle and calculate the cabin posture. Limited by the camera measurement range, this method is difficult to achieve high-precision measurement for large-diameter cabins. Summary of the invention

[0003] The purpose of the invention is to solve the problems of complex operation, low automation level, poor docking quality and low docking efficiency in the current cabin docking and to propose a cabin docking measurement method.

[0004] According to one aspect of an embodiment of the present invention, a cabin section docking measurement method is provided, comprising: adjusting a cabin section to be docked to a pre-installed position; using a 2D laser displacement sensor to obtain 2D contour data of multiple points at the docking position of the flanges of the two cabin sections; based on the 2D contour data of the above multiple points, identifying multiple edge points on the flanges of the reference cabin section and the cabin section to be docked, and obtaining the spatial positions of the multiple edge points on the flanges of the cabin section to be docked; according to the spatial positions of the multiple edge points on the flanges of the cabin section to be docked, obtaining the spatial position of the plane of the flange of the cabin section to be docked by least squares fitting, and then obtaining the spatial angular deviation of the end face of the cabin section to be docked relative to the end face of the reference cabin section; according to the spatial positions of the multiple edge points on the flanges of the cabin section to be docked, combined with the geometric shape of the cabin flange, matching and calculating to obtain other degree of freedom deviations of the cabin section to be docked relative to the reference cabin section; and sending the measurement results to the actuator to complete the posture adjustment of the cabin section to be docked.

[0005] Optionally, a 2D laser displacement sensor is used to obtain 2D profile data of multiple points at the joint of the two compartment flanges, including:

[0006] Establish the cabin joint flange model, and define the reference coordinate system O with the center of the reference cabin flange end face contour as the origin. b -X b Y b Z b , define the axial direction of the end face of the cabin as X b Axis, define the horizontal direction of the end face as Y b , define the vertical direction of the end face as Z b ;

[0007] According to the measurement principle of 2D laser displacement sensor, the camera coordinate system is established and recorded as O c -X c Y c Z c , the coordinate system X of multiple detection positions c Direction and reference coordinate system X b The directions are consistent, and multiple detection positions are relative to the base coordinate system X b The rotation angle of the direction is denoted as θ i (1≤i≤n), where n represents the number of detection positions;

[0008] A 2D laser displacement sensor is used to obtain 2D contour data of multiple points at the joint of the two compartment flanges at multiple detection positions.

[0009] Optionally, based on the 2D contour data of multiple points, multiple edge points on the flanges of the reference cabin section and the cabin section to be docked are identified to obtain the spatial positions of the multiple edge points on the flanges of the cabin section to be docked, including:

[0010] When there are three detection positions, in the camera coordinate system, the three edge points P on the flange of the reference compartment are identified according to the 2D contour data of the three points. c1 , P c2 , P c3 and three edge points P on the flange of the docking compartment c1 '、P c2 '、P c3 ';

[0011] According to the reference cabin docking flange model, the coordinates of the three edge points of the reference cabin flange in the reference coordinate system at the three detection positions are calculated and recorded as: P b1 , P b2 , P b3 , then the coordinates of the three edge points on the flange of the docking compartment in the reference coordinate system are:

[0012]

[0013] in

[0014]

[0015] Optionally, according to the spatial positions of multiple edge points on the flange of the to-be-joined cabin section, the spatial position of the to-be-joined flange plane is obtained by least squares fitting, and then the spatial angle deviation of the end face of the to-be-joined cabin section relative to the end face of the reference cabin section is obtained, including:

[0016] According to the spatial position P of multiple edge points on the flange of the docking compartment b1 '、P b2 ', ..., P bn 'Through the least square method, the spatial equation of the flange plane of the docking compartment is obtained by fitting calculation, which is recorded as: Ax+By+Cz+D=0;

[0017] The end face equation of the reference cabin is z=0. Based on the two plane equations, the two rotation components of the cabin to be docked relative to the reference cabin, excluding the rotation angle, can be obtained: the pitch angle β and the deflection angle γ.

[0018] Optionally, according to the spatial positions of multiple edge points on the flange of the cabin to be docked, combined with the geometric shape of the cabin flange, other degrees of freedom deviations of the cabin to be docked relative to the reference cabin are obtained by matching calculation, including:

[0019] According to the spatial position P of multiple edge points on the flange of the docking compartment b1 '、P b2 ', ..., P bn ', and its projection points on the plane Ax+By+Cz+D=0 are denoted as: Q b1 , Q b2 ,…,Q bn According to the flange contour of the docking compartment, the coordinates P of the center of the flange end face contour of the docking compartment in the reference coordinate system are obtained by fitting O =[x b ,y b ,z b ] T and its rotation angle α (for cylindrical cabin sections, the rotation angle is not calculated).

[0020] For the circular flange cabin, docking mark features are designed on the reference cabin and the cabin to be docked. The 2D images of the docking mark positions on the flanges of the two cabins are acquired by using an area array camera. The relative position deviation S of the docking mark is obtained by the image processing algorithm, and the rotation angle α of the cabin to be docked relative to the reference cabin is further calculated:

[0021] α=S / R

[0022] Where R is the coordinate of the docking mark feature point in Y b Z b The projected length of the plane.

[0023] The method provided by the present invention is to detect and calculate the flange joints of the two cabins in real time by means of multiple 2D laser displacement sensors distributed at different positions of the two cabins, and complete the real-time measurement of the relative posture of the two cabins with high measurement efficiency; the object measured by this method is not limited to circular flange cabins, and accurate measurement of non-circular flange cabins can also be achieved; this method is a non-contact measurement method that is detached from the target and does not require human participation; this method calculates the relative posture of the cabins by obtaining the contour information of different points on the flange joint surfaces of the two cabins, so this method is applicable to cabins of different sizes, and the measurement accuracy is not affected by the size of the cabin. This method solves the problems of low automation level, low docking efficiency, and difficult to ensure docking quality in the field of cabin docking. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 A flow chart of a cabin docking measurement method of the present invention

[0026] Figure 2 The cabin section docking flange model of the present invention;

[0027] Figure 3 Schematic diagram of circular compartment detection position in an embodiment of the present invention;

[0028] Figure 4 The figure is a flow chart of the cabin docking part in an embodiment of the present invention.

[0029] The above-mentioned Figure 3 The following reference numerals are included:

[0030] 1. Reference module, 2. Docking mark of reference module, 3. 2D array camera, 4. Docking mark of module to be docked, 5. Laser, 6. Module to be docked. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] The present invention provides an embodiment of a cabin docking measurement method. Figure 1The flowchart of the method used in this embodiment is shown, which specifically includes the following steps:

[0033] Step S1, adjust the cabin to be docked to a pre-installed position about 50 mm away from the reference cabin, and use a 2D laser displacement sensor to obtain 2D contour data of multiple points at the docking of the flanges of the two cabins;

[0034] Step S2, based on the 2D contour data of the above multiple points, identify multiple edge points on the flanges of the reference cabin section and the cabin section to be docked, and obtain the spatial positions of the multiple edge points on the flanges of the cabin section to be docked;

[0035] Step S3, according to the spatial positions of multiple edge points on the above-mentioned cabin section flange, the spatial position of the plane of the cabin section flange to be docked is obtained by least squares fitting, and then the spatial angle deviation of the end face of the cabin section to be docked relative to the end face of the reference cabin section is obtained;

[0036] Step S4, according to the spatial positions of the plurality of edge points on the above-mentioned cabin flange to be docked, combined with the geometric shape of the cabin flange, matching and calculating to obtain the other degree of freedom deviations of the cabin to be docked relative to the reference cabin;

[0037] Step S5, sending the measurement results to the actuator to complete the posture adjustment of the cabin to be docked.

[0038] In step S1, a 2D laser displacement sensor is used to obtain 2D contour data of multiple points at the joint of the two compartment flanges, specifically including:

[0039] Establish the cabin joint flange model, such as Figure 2 The reference coordinate system O is defined with the center of the flange end face profile of the reference compartment as the origin. b -X b Y b Z b , define the axial direction of the end face of the cabin as X b Axis, define the horizontal direction of the end face as Y b , define the vertical direction of the end face as Z b ; According to the measurement principle of 2D laser displacement sensor, the camera coordinate system is established and recorded as O c -X c Y c Z c .like Figure 3 As shown, three detection positions are set around the flanges of the two compartments, namely the first detection position, the second detection position, and the third detection position. The coordinate system X of the three detection positions c Direction and reference coordinate system X b The directions are consistent, where the angle between the first detection position and the second detection position is θ 1 , and the angle between it and the third detection position is θ 2 ;

[0040] A 2D profile sensor composed of an area array camera and a laser is used to obtain 2D profile data at the first point position, the second point position, and the third point position on the flanges of the two cabin sections at the first detection position, the second detection position, and the third detection position;

[0041] In step S2, based on the 2D contour data of the above-mentioned multiple points, multiple edge points on the flanges of the reference cabin section and the cabin section to be docked are identified to obtain the spatial positions of the multiple edge points on the flanges of the cabin section to be docked, which specifically includes:

[0042] In the camera coordinate system, the three edge points P on the flange of the reference compartment are identified based on the 2D contour data of the three points. c1 , P c2 , P c3 and multiple edge points P on the flange of the docking compartment c1 '、P c2 '、P c3 ';

[0043] According to the reference cabin docking flange model, the coordinates of the three edge points of the reference cabin flange in the reference coordinate system at the three detection positions are calculated and recorded as: P b1 , P b2 , P b3 , then the coordinates of the three edge points on the flange of the docking compartment in the reference coordinate system are:

[0044]

[0045] in

[0046]

[0047] In step S3, the spatial position of the plane of the flange of the cabin to be docked is obtained by least square fitting according to the spatial positions of multiple edge points on the above-mentioned cabin flange, and then the spatial angle deviation of the end face of the cabin to be docked relative to the end face of the reference cabin is obtained, including:

[0048] The relative position of the two cabins in any posture is expressed by six degrees of freedom, namely, x deviation, y deviation, z deviation, rotation angle, pitch angle, and deflection angle, denoted by x b ,y b 、z b , α, β, γ;

[0049] According to the spatial position P of the three edge points on the flange of the docking compartment b1 '、P b2 '、P b3 'Through the least square method, the spatial equation of the flange plane of the docking compartment is obtained by fitting calculation, which is recorded as: Ax+By+Cz+D=0;

[0050] The end face equation of the reference cabin is z=0. Based on the two plane equations, the two rotation components of the cabin to be docked relative to the reference cabin, excluding the rotation angle, can be obtained: the pitch angle β and the deflection angle γ.

[0051] In step S4, according to the spatial positions of the plurality of edge points on the flange of the cabin to be docked, combined with the geometric shape of the cabin flange, the other degree of freedom deviations of the cabin to be docked relative to the reference cabin are obtained by matching calculation, including:

[0052] According to the spatial position P of multiple edge points on the flange of the docking compartment b1 '、P b2 ', ..., P bn ', and its projection points on the plane Ax+By+Cz+D=0 are denoted as: Q b1 , Q b2 ,…,Q bn According to the flange contour of the docking compartment, the coordinates P of the center of the flange end face contour of the docking compartment in the reference coordinate system are obtained by fitting O =[x b ,y b ,z b ] T and its rotation angle α (for cylindrical cabin sections, the rotation angle is not calculated).

[0053] For circular flange compartments, such as Figure 3 As shown in the figure, docking mark features are designed on the reference cabin and the cabin to be docked, respectively. An area array camera is used to obtain 2D images of the docking mark positions on the flanges of the two cabins. The relative position deviation S of the docking mark is obtained by the image processing algorithm, and the rotation angle α of the cabin to be docked relative to the reference cabin is further calculated:

[0054] α=S / R

[0055] Where R is the coordinate of the docking mark feature point in Y b Z b The projected length of the plane.

[0056] In step S5, the above measurement results are sent to the actuator to complete the cabin docking posture adjustment operation. The docking process is as follows: Figure 4 As shown, the specific steps include:

[0057] The first acquisition step is to obtain the relative position α, β, γ, x of the docking compartment relative to the reference compartment. b ,y b 、z b ;

[0058] The first adjustment step is to drive the actuator to adjust α, β, γ, y b and zb ;

[0059] The second acquisition step is to obtain the relative position α, β, γ, x of the docking compartment relative to the reference compartment. b ,y b 、z b ;

[0060] The first judgment step is to judge α, β, γ, and y b and z b Whether all the accuracy requirements are met, if not, return to the first adjustment step; if yes, proceed to the next step;

[0061] The second adjustment step is to drive the actuator to adjust x b Deviation completes the cabin docking operation.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cabin docking measurement method, characterized in that: include: Adjust the cabin section to be docked to the pre-installation position; Use 2D laser displacement sensors to obtain 2D contour data of multiple points at the joint of the two compartment flanges; A reference coordinate system is defined with the center of the end face contour of the reference cabin section flange as the origin, and based on the 2D contour data of the above-mentioned multiple points, multiple edge points on the flanges of the reference cabin section and the cabin section to be docked are identified to obtain the spatial positions of the multiple edge points on the flange of the cabin section to be docked; According to the spatial positions of multiple edge points on the above-mentioned cabin section flange, the spatial position of the plane of the cabin section flange to be docked is obtained by least square fitting, and then the pitch angle and deflection angle of the end face of the cabin section to be docked relative to the end face of the reference cabin section are obtained; According to the spatial positions of multiple edge points on the flange of the cabin to be docked, combined with the contour shape of the flange of the cabin to be docked, the coordinates of the center of the flange end face contour of the cabin to be docked in the reference coordinate system and the rotation angle of the cabin to be docked relative to the reference cabin are matched and calculated. For the cabin with a circular flange, the rotation angle is not calculated. For the cabin with a circular flange, a 2D image of the docking mark position on the flanges of the two cabins is obtained by using an array camera to calculate the rotation angle of the cabin to be docked relative to the reference cabin. The measurement results are sent to the actuator to complete the position adjustment of the docking module.

2. The method for measuring cabin docking according to claim 1, characterized in that: A 2D laser displacement sensor is used to obtain 2D contour data of multiple points at the joint of the two compartment flanges, including: Establish the cabin joint flange model, and define the reference coordinate system O with the center of the reference cabin flange end face contour as the origin. b -X b Y b Z b , define the axial direction of the end face of the cabin as X b Axis, define the horizontal direction of the end face as Y b , define the vertical direction of the end face as Z b ; According to the measurement principle of 2D laser displacement sensor, the camera coordinate system is established and recorded as O c -X c Y c Z c , the coordinate system X of multiple detection positions c Direction and reference coordinate system X b The directions are consistent, and multiple detection positions are relative to the reference coordinate system X b The rotation angle of the direction is denoted as θ i (1≤i≤n), where n represents the number of detection positions; A 2D laser displacement sensor is used to obtain 2D contour data of multiple points at the flange joint of the two compartment sections at multiple detection positions.

3. The method for measuring cabin docking according to claim 2, characterized in that: Based on the 2D contour data of multiple points, multiple edge points on the flanges of the reference cabin and the cabin to be docked are identified, and the spatial positions of multiple edge points on the flanges of the cabin to be docked are obtained, including: When there are three detection positions, in the camera coordinate system, the three edge points P on the flange of the reference compartment are identified according to the 2D contour data of the three points. c1 , P c2 , P c3 and three edge points P on the flange of the docking compartment c1 '、P c2 '、P c3 '; According to the reference cabin docking flange model, the coordinates of the three edge points of the reference cabin flange in the reference coordinate system at the three detection positions are calculated and recorded as: P b1 , P b2 , P b3 , then the coordinates of the three edge points on the flange of the docking compartment in the reference coordinate system are: in 4. The method for measuring cabin docking according to claim 1, characterized in that: According to the spatial positions of multiple edge points on the flange of the cabin to be docked, the spatial position of the flange plane of the cabin to be docked is obtained by least square fitting, and then the pitch angle and deflection angle of the end face of the cabin to be docked relative to the end face of the reference cabin are obtained, including: According to the spatial position P of multiple edge points on the flange of the docking compartment b1 '、P b2 ', ..., P bn ', the spatial equation of the flange plane of the docking compartment is obtained by fitting and calculating with the least square method, which is recorded as: Ax+By+Cz+D=0; The end face equation of the reference cabin is z=0. Based on the two plane equations, the two rotation components of the cabin to be docked relative to the reference cabin, excluding the rotation angle, can be obtained: the pitch angle β and the deflection angle γ.

5. The method for measuring cabin docking according to claim 4, characterized in that: According to the spatial positions of multiple edge points on the flange of the cabin to be docked, combined with the contour shape of the flange of the cabin to be docked, the coordinates of the center of the flange end face contour of the cabin to be docked in the reference coordinate system and the rotation angle of the cabin to be docked relative to the reference cabin are obtained by matching and calculating. For the circular flange cabin, the rotation angle is not calculated. For circular flange cabins, an array camera is used to obtain 2D images of the docking mark positions on the flanges of the two cabins, and the rotation angle of the cabin to be docked relative to the reference cabin is calculated, including: According to the spatial position P of multiple edge points on the flange of the docking compartment b1 '、P b2 ', ..., P bn ', and its projection points on the plane Ax+By+Cz+D=0 are denoted as: Q b1 , Q b2 , …, Q bn According to the flange contour of the docking compartment, the coordinates of the center of the flange end face contour of the docking compartment in the reference coordinate system are obtained by fitting and the rotation angle α of the cabin to be docked relative to the reference cabin. For the circular flange cabin, the rotation angle is not calculated; For the circular flange cabin, docking mark features are designed on the reference cabin and the cabin to be docked. The 2D images of the docking mark positions on the flanges of the two cabins are acquired by using an area array camera. The relative position deviation S of the docking mark is obtained by the image processing algorithm, and the rotation angle α of the cabin to be docked relative to the reference cabin is further calculated: α=S / R Where R is the coordinate of the docking mark feature point in Y b Z b The projected length of the plane.

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