CN108151660B - A kind of aircraft components butt-joint clearance and the measurement equipment of scale, method and system - Google Patents

Abstract

The invention discloses a measuring device, method and system for the butt gap and step difference of aircraft components. The measuring equipment includes a positioning device, a measuring device and an upper computer; the positioning device includes a positioning tool; the measuring device includes a ring track, a measuring head, a measuring head driving device and a ring track driving device. By arranging the ring track and the measuring head on the positioning tool, the measuring head driving device can drive the measuring head to move along the ring track, and the ring track driving device can drive the ring track A translational movement is carried out on the positioning tool. Therefore, the measurement of the contour data of the entire docking area of the aircraft component under test can be realized through the movement of the measuring head and the ring track, which can effectively avoid the defect of low measurement accuracy caused by only measuring local feature points and incomplete measurement data, so as to realize the measurement of the measured data. High-precision measurement of butt gaps and steps in aircraft components.

Description

Equipment, method and system for measuring butt gap and step difference of aircraft components

technical field

The invention relates to the technical field of aircraft intelligent assembly, in particular to a measuring device, method and system for the butt gap and step difference of aircraft components.

Background technique

The outer surface of the aircraft is made up of many components. The geometric accuracy of the splicing directly affects the aerodynamic and electromagnetic continuity of the aircraft, and is an important indicator that affects the maneuverability, stealth and life of the aircraft. At present, aircraft assembly has been transformed from manual assembly to CNC automatic assembly, and is moving towards intelligent assembly. For the assembly process of aircraft components, the automatic measurement of the gap and level difference in the docking area is the basis for the attitude adjustment and trimming of CNC equipment, and it is also the key to the transformation of aircraft assembly to intelligence.

In the traditional assembly of small aircraft components, manual manual measurement is used to measure the deviation of the docking area. There are problems such as cumbersome measurement, repeated adjustment process, low efficiency and poor accuracy, which cannot meet the development needs of modern large aircraft assembly. In digital assembly, Boeing uses laser tracker or lidar to measure the space attitude of large parts of the aircraft, and then adjusts the position and attitude of the large parts of the aircraft to realize the docking and assembly work of large parts of the aircraft; most of the docking measurement of large aircraft developed in China adopts laser tracking The instrument measures the coordinates of the positioning point of the component, maps it with the theoretical value and adjusts the attitude to complete the docking. However, the above method has the defects of only measuring local feature points and incomplete measurement data when measuring the docking gap and step difference of large aircraft components, so the accuracy required in the docking process of large aircraft components cannot be achieved.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a measuring device, method and system for the butt gap and step difference of aircraft parts, by measuring the point cloud data of the outline of the entire butt area of the aircraft part to be tested, to achieve a high level of the butt gap and step difference of the aircraft part to be tested Accuracy measurement.

For achieving the above object, the present invention provides the following scheme:

A measuring equipment for the butt gap and step difference of aircraft components, the measuring equipment includes a positioning device, a measuring device and a host computer; the positioning device includes a positioning tool; the measuring device includes a ring track, a measuring head, and a measuring head driving device and ring track drive;

The aircraft component to be tested is mounted on the positioning device;

The ring track is installed on the positioning tool, and the measurement head is installed on the ring track; the ring track is used to ensure that there is a preset distance between the measurement head and the aircraft component to be measured;

The measuring head driving device is installed on the ring track, the measuring head driving device is connected with the measuring head, and is used for driving the measuring head to move along the ring track;

The ring track driving device is installed on the positioning tool, the ring track driving device is connected with the ring track, and is used for driving the ring track to perform translational movement on the positioning tool;

The measuring head is connected to the host computer; the measuring head is used to measure the contour data of the docking area of the aircraft component under test; the host computer is used to calculate the measured contour data according to the contour data of the docking area Butt gaps and steps in the docking area of aircraft components.

Optionally, the measuring head is a line structured light vision sensor.

Optionally, the measurement device further includes a calibration block and a laser tracking device;

The calibration block is installed on the bottom of the positioning tool; the laser tracking device is installed on the top of the ring track; the calibration block and the laser tracking device are used to determine the position of the ring track and the measuring head.

Optionally, the calibration block is a trapezoidal block structure; the number of the calibration blocks is multiple; and the multiple calibration blocks are installed at the bottom of the positioning tool at equal intervals.

Optionally, the positioning device further includes an attitude adjustment tool; the attitude adjustment tool is located on one side of the positioning tool; a roller is installed at the bottom of the attitude adjustment tool; The steps are used to adjust the docking attitude and trim the aircraft components under test.

The invention also discloses a method for measuring the butt gap and step difference of aircraft parts, the measurement method is applied to the measurement equipment for the butt gap and step difference of the aircraft parts, and the measurement method comprises:

Obtain the contour data of the docking area of the aircraft component under test;

generating a measurement model of the docking area according to the contour data of the docking area;

obtaining a theoretical model of the docking region;

According to the measurement model of the butt region and the theoretical model of the butt region, the butt gap and step difference of the butt region of the tested aircraft component are obtained.

Optionally, the acquiring the contour data of the docking area of the aircraft component under test specifically includes:

Obtain the contour data of the docking area of the tested aircraft part; the contour data of the docking area of the tested aircraft part is a plurality of point cloud data measured by the measuring head; each of the point cloud data is a measurement point at Measure the coordinate value in the coordinate system.

Optionally, the generating of the measurement model of the docking area according to the contour data of the docking area specifically includes:

Convert the coordinate value of each measurement point under the measurement coordinate system into the coordinate value under the workpiece coordinate system, and obtain point cloud data under multiple workpiece coordinate systems;

A least squares method is used to fit the point cloud data under the multiple workpiece coordinate systems to generate a measurement model of the docking area.

Optionally, according to the measurement model of the docking area and the theoretical model of the docking area, the docking clearance and step difference of the docking area of the aircraft component under test are obtained, specifically including:

Discretize the theoretical model of the docking area to generate discrete point cloud data of the same order of magnitude as the point cloud data under the workpiece coordinate system; each of the discrete point cloud data is a coordinate value of a discrete point;

Matching a plurality of the measurement points in the docking area of the aircraft component under test with a plurality of the discrete points in the corresponding positions in the theoretical model to obtain matching point pairs of the measurement points and the discrete points;

Obtain the coordinate value of the measurement point in the matching point pair under the workpiece coordinate system;

obtaining the coordinate values of the discrete points in the matching point pair;

Calculate the deviation value of the coordinate value of the measurement point in the workpiece coordinate system and the coordinate value of the discrete point in the length direction to obtain the docking gap of the docking area of the aircraft component under test;

Calculate the deviation value of the coordinate value of the measurement point in the workpiece coordinate system and the coordinate value of the discrete point in the height direction, and obtain the step difference of the docking area of the tested aircraft component.

The invention also discloses a measurement system for the butt gap and step difference of aircraft components, the measurement system comprising:

The contour data acquisition module is used to obtain the contour data of the docking area of the tested aircraft component;

a measurement model generation module for generating a measurement model of the docking area according to the contour data of the docking area;

a theoretical model acquisition module for acquiring the theoretical model of the docking area;

A butt gap and step difference obtaining module is used to obtain the butt gap and step difference of the butt area of the tested aircraft component according to the measurement model of the butt area and the theoretical model of the butt area.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

The invention provides a measuring device, method and system for the butt gap and step difference of aircraft components. The measuring equipment includes a positioning device, a measuring device and an upper computer; the positioning device includes a positioning tool; the measuring device includes a ring track, a measuring head, a measuring head driving device and a ring track driving device. By arranging the ring track and the measuring head on the positioning tool, the measuring head driving device can drive the measuring head to move along the ring track, and the ring track driving device can drive the ring track A translational movement is carried out on the positioning tool. Therefore, the measurement of the contour data of the entire docking area of the aircraft component under test can be realized through the movement of the measuring head and the ring track, which can effectively avoid the defect of low measurement accuracy caused by only measuring local feature points and incomplete measurement data, so as to realize the measurement of the measured data. The high-precision measurement of the docking clearance and step difference of aircraft components can provide accurate data support for the docking attitude and trimming of aircraft components, and realize the precise assembly of large aircraft components.

In addition, the measuring head used in the present invention is a line structured light vision sensor, and the line structured light vision sensor is a non-contact, stable and ultra-high-speed measurement sensor, which is used in the present invention for docking measurement of large aircraft components, It can improve the quality and efficiency of the measurement of the butt gap and step difference of the aircraft components, as well as the assembly of the aircraft components, and reduce the cost. At the same time, the present invention also uses the calibration block and the laser tracking device to calibrate the position of the measuring head and the ring track, which further improves the measurement accuracy of the butt gap and step difference of the aircraft components to be measured.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

Fig. 1 is a kind of structural schematic diagram of the measurement equipment of the butt gap and step difference of a kind of aircraft parts provided by the present invention;

Fig. 2 is a method flow chart of a method for measuring the butt gap and step difference of an aircraft component provided by the present invention;

3 is a schematic diagram of a measurement coordinate system and a tooling coordinate system provided by an embodiment of the present invention;

4 is a schematic diagram of a laser tracker coordinate system provided by an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a system for measuring the docking clearance and step difference of aircraft components provided by the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The purpose of the present invention is to provide a measuring device, method and system for the butt gap and step difference of aircraft parts, by measuring the point cloud data of the outline of the entire butt area of the aircraft part to be tested, to achieve a high level of the butt gap and step difference of the aircraft part to be tested Accuracy measurement.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a schematic structural diagram of a device for measuring the docking clearance and step difference of aircraft components provided by the present invention. Referring to FIG. 1 , a device for measuring the docking clearance and step difference of aircraft components provided by the present invention includes a positioning device, a measuring device and a host computer. The positioning device includes a positioning tool 101 . The measuring device includes a ring track 102 , a measuring head 103 , a measuring head driving device 104 and a ring track driving device 105 .

The aircraft part 106 under test is mounted on the positioning device.

The ring rail 102 is mounted on the positioning tool 101 , and the measuring head 103 is mounted on the ring rail 102 . The ring track 102 is used to ensure that there is a preset distance between the measuring head 103 and the aircraft component 106 to be tested.

The measurement head driving device 104 is mounted on the ring track 102 , and the measurement head driving device 104 is connected with the measurement head 103 for driving the measurement head 103 to move along the ring rail 102 .

The ring track driving device 105 is installed on the positioning tool 101 , and the ring track driving device 105 is connected to the ring track 102 for driving the ring track 102 to perform translational movement on the positioning tool 101 .

The measuring head 103 is connected to the upper computer 107 . The measuring head 103 is used to measure the contour data of the docking area of the aircraft component 106 under test. The upper computer 107 is configured to calculate the docking gap and the level difference of the docking area of the tested aircraft component 106 according to the contour data of the docking area.

The upper computer 107 is also connected to the measuring head driving device 104 and the ring track driving device 105 respectively, for controlling the operation of the measuring head driving device 104 and the ring track driving device 105 .

After the large-scale tested aircraft components 106 are docked, the measuring head driving device 104 drives the measuring head 103 to move at equal intervals along the ring track 102. The moving distance is roughly controlled by the internal encoder of the drive motor. The encoder signal triggers the laser tracking device 109 to record the position of the measuring head 103, and at the same time, the data acquisition unit in the host computer 107 records the contour data of the docking area. Due to the large area of the docking area of large aircraft components, multiple scans are required, that is, after one scan along the ring track is completed, the ring track driving device 105 drives the ring track 102 to move equidistant distances, and then the measuring head driving device 104 The measurement head 103 is driven to perform the next scan. Until all the docking areas of the aircraft part 106 under test are scanned.

The data measured by the measuring head 103 at one time is not the data of the entire contour, the measured data needs to be cleaned, and the superposition principle is used to splicing the measured data to obtain the data of the entire measured contour.

Wherein, the measuring head 103 is a line structured light vision sensor. The line structured light vision sensor is a non-contact, stable and ultra-high-speed measurement sensor. The present invention uses it for the butt measurement of large aircraft parts, which can improve the accuracy and efficiency of the measurement of the butt gap and step difference of the aircraft parts, thereby improving the The quality and efficiency of aircraft component assembly, reducing costs.

The measuring device also includes a calibration block 108 and a laser tracking device 109 . The laser tracking device 109 is a laser tracker. The calibration block 108 is installed on the bottom of the positioning tool 101 . The calibration block 108 is a trapezoidal block structure, and the measurement head 103 can be calibrated by three-point measurement. The three points are the three points 1, 2, and 3 on the calibration block 103 of the trapezoidal block structure in FIG. 1 . The position of the measurement head 103 is related to the accuracy of the measurement data. The number of the calibration blocks 108 is multiple. The number of the calibration blocks 108 is determined according to the measurement range of the measuring head 103 and the size of the docking area, and generally the more the more accurate, the more accurate. The calibration blocks 108 are kept at equal intervals, and a plurality of the calibration blocks 108 are installed at the bottom of the positioning tool 101 at equal intervals.

The calibration block 108 is used to determine the corresponding relationship between the measuring head 103 and the tool (the positioning tool and the attitude adjustment tool are collectively referred to as tool in the present invention), and the moving distance of the ring track 102 driven by the guide ring track driving device 105 . The distance that the ring track driving device 105 drives the ring track 102 to move must be within the measurable range of the measuring head 103, and the data of the two measurements may partially overlap. Since the relative distance between the two calibration blocks 108 is determined, the moving distance of the loop track 102 can be determined by interpolation. According to the size of the docking area, set the number of calibration blocks 108, such as calibration block A, calibration block B, calibration block C, etc., and scan them with the laser tracking device 109 to determine that the calibration blocks 108 are installed at equal intervals . The laser tracking device 109 is mounted on top of the ring track 102 . The calibration block 108 and the laser tracking device 109 are used to calibrate the positions of the ring track 102 and the measuring head 103 , so that the ring track 102 and the measuring head 103 can move at equal intervals.

By calibrating the positions of the measuring head 103 and the ring track 102 by the calibration block 108 and the laser tracking device 109, the accuracy of measuring the contour data of the entire docking area of the aircraft component under test can be further improved, thereby further improving Accuracy of butt clearance and step measurement of aircraft components under test.

The docking of large aircraft components generally requires two toolings (a positioning tool and an attitude adjustment tool) to operate, so the positioning device includes the positioning tool and the attitude adjustment tool. The positioning tool is used for fixing the measuring device. The posture-adjusting tooling has a docking function and can be moved. That is, the positioning device further includes a posture adjustment tool 110 . The posture adjustment tool 110 is located on one side of the positioning tool 101 . A roller 111 is installed at the bottom of the posture adjustment tool 110 so that the posture adjustment tool 110 can move. The attitude adjustment tool 110 is used for docking attitude adjustment and trimming of the aircraft component 106 under test according to the docking clearance and step difference.

It can be seen that the present invention provides a measurement equipment for the butt gap and step difference of aircraft components. By arranging the ring track 102 and the measuring head 103 on the positioning tool 101, the measuring head driving device 104 can drive the The measuring head 103 moves along the ring track 102 , and the ring track driving device 105 can drive the ring track 102 to perform translational movement on the positioning tool 101 . Therefore, the measurement of the contour data of the entire docking area of the aircraft component 106 under test can be realized by the movement of the measuring head 103 and the ring track 102, which can effectively avoid the defect of low measurement accuracy caused by only measuring local feature points and incomplete measurement data. To achieve high-precision measurement of the docking gap and step difference of the aircraft components under test, it can provide accurate data support for the docking attitude adjustment and edge trimming of the aircraft components, and realize the precise assembly of large aircraft components.

The invention also provides a method for measuring the butt gap and step difference of aircraft components, and the measurement method is applied to the measurement equipment for the butt gap and step difference of the aircraft components. FIG. 2 is a method flow chart of a method for measuring the butt gap and step difference of an aircraft component provided by the present invention. Referring to Figure 2, the measurement method includes:

Step 201: Acquire contour data of the docking area of the tested aircraft component.

The contour data of the docking area of the aircraft component under test is a plurality of point cloud data measured by the measuring head; each of the point cloud data is a coordinate value of a measurement point in the measurement coordinate system.

Step 202: Generate a measurement model of the docking area according to the contour data of the docking area.

The step 202 specifically includes:

The coordinate values of each measurement point under the measurement coordinate system are converted into coordinate values under the workpiece coordinate system, and point cloud data under multiple workpiece coordinate systems are obtained.

To realize the conversion between the measurement coordinate system and the workpiece coordinate system, the corresponding relationship between the workpiece coordinate system, the tooling coordinate system, the laser tracker coordinate system and the measuring head coordinate system must first be established, specifically:

The first step is to establish the correspondence between the workpiece coordinate system X ₂ Y ₂ Z ₂ and the tooling coordinate system X ₁ Y ₁ Z ₁ .

The tool coordinate system X ₁ Y ₁ Z ₁ is the coordinate system set on the docking tool (including the positioning tool and the attitude adjustment tool) of the aircraft component under test, and the workpiece coordinate system X ₂ Y ₂ Z ₂ is the coordinate system on the aircraft under test. The coordinate system set on the part.

Establish a reference point O ₁ (x ₁ , y ₁ , z ₁ ) of the tool coordinate system X ₁ Y ₁ Z ₁ on the docking tool, and use the laser tracking device 109 to correct the reference point O ₁ (x ₁ , y ₁ , z ₁ ) position to ensure accurate position. The reference point O ₂ (x ₂ , y ₂ , z ₂ ) of the workpiece coordinate system X ₂ Y ₂ Z ₂ is established on the aircraft part to be tested. The reference point O ₂ (x ₂ , y ₂ , z ₂ ) of the workpiece coordinate system X ₂ Y ₂ Z ₂ is relative to the reference point O ₁ (x ₁ , y ₁ of the tool coordinate system X ₁ Y ₁ Z ₁ ) , z ₁ ) coordinate offset is

The theoretical tooling (positioning device) and the workpiece (the aircraft part under test) are kept in close contact, regardless of the deformation of the workpiece, the corresponding relationship of the coordinate system is:

Wherein, Δx ₂ represents the coordinate offset of the workpiece coordinate system X ₂ Y ₂ Z ₂ relative to the tool coordinate system X ₁ Y ₁ Z ₁ in the X direction; Δy ₂ represents the workpiece coordinate system X ₂ Y ₂ Z ₂ is relative to the coordinate offset of the tool coordinate system X ₁ Y ₁ Z ₁ in the Y direction; Δz ₂ represents the workpiece coordinate system X ₂ Y ₂ Z ₂ relative to the tool coordinate system X ₁ Y ₁ Z The coordinate offset of ₁ in the Z direction.

In the second step, the measuring device is fixed on the positioning tool 101, the measuring head 103 is calibrated with the laser tracking device 109, and the measuring coordinate system X ₃ Y ₃ Z ₃ and the tooling coordinate system X ₁ are established The correspondence between Y ₁ Z ₁ . FIG. 3 is a schematic diagram of a measurement coordinate system and a tooling coordinate system provided by an embodiment of the present invention. The Bursa-Wolf model is chosen as the transformation model between the measurement coordinate system X ₃ Y ₃ Z ₃ and the tooling coordinate system X ₁ Y ₁ Z ₁ .

Let X ₁ Y ₁ Z ₁ be the tool coordinate system, the reference point O ₁ (x ₁ , y ₁ , z ₁ ) is the origin of the tool coordinate system X ₁ Y ₁ Z ₁ ; X ₃ Y ₃ Z ₃ is the measurement coordinate The reference point O ₃ (x ₃ , y ₃ , z ₃ ) is the origin of the measurement coordinate system X ₃ Y ₃ Z ₃ ; the origin of the measurement coordinate system and the tooling coordinate system do not coincide, and there is a deflection angle. The coordinate value of the origin O ₃ (x ₃ , y ₃ , z ₃ ) of the measuring coordinate system X ₃ Y ₃ Z ₃ in the tooling coordinate system X ₁ Y ₁ Z ₁ is The Euler angle of the measurement coordinate system X ₃ Y ₃ Z ₃ relative to the tool coordinate system X ₁ Y ₁ Z ₁ is [ε _X ε _Y ε _Z ], and the scaling factor between the measurement coordinate system and the tool coordinate system is k, There are seven parameters in total, denoted as [Δx ₃ Δy ₃ Δz ₃ ε _X ε _Y ε _Z k]. Let P _J be a common associated point, and the coordinate value of P _J in the measurement coordinate system is The coordinate value in the tooling coordinate system is According to the Bursa-Wolfe seven-parameter transformation model:

in,

The third step is to use the laser tracking device 109 to determine the position B (x _B , y _B , z _B ) of the calibration block 108 in the tool coordinate system, according to the coordinates of point B in the laser tracker coordinate system and the coordinates of point B in the tool coordinate system The coordinates under the system can calculate the coordinates of the laser tracker. FIG. 4 is a schematic diagram of a coordinate system of a laser tracker provided by an embodiment of the present invention. Referring to Figure 4, the coordinate relationship of point B in the laser tracker coordinate system is:

Among them, d represents the distance between point B and the origin of the laser tracker coordinate system, α represents the angle between point B and the XOZ plane of the laser tracker coordinate system, and β represents the projection of point B on the XOY plane of the laser tracker coordinate system. The included angle of the XOZ plane.

Set the calibration block A to be fixed on the tooling, and determine its coordinate value in the tooling coordinate system through the laser tracker The coordinate value of calibration block A in the laser tracker coordinate system is The corresponding relationship between the tool coordinate system and the laser tracker coordinate system can be determined. Then, the coordinate value of the measuring head in the coordinate system under the laser tracker is determined by the laser tracker, and the corresponding relationship between the measuring head and the tooling coordinate system is established. Thus, the coordinate transformation relationship between the laser tracker, the tooling and the calibration block can be realized.

The fourth step, according to the corresponding relationship between the workpiece coordinate system X ₂ Y ₂ Z ₂ and the tool coordinate system X ₁ Y ₁ Z ₁ , the measurement coordinate system X ₃ Y ₃ Z ₃ and the tool coordinate system X ₁ Y ₁ Z ₁ The corresponding relationship between the measurement coordinate system X ₃ Y ₃ Z ₃ and the workpiece coordinate system X ₂ Y ₂ Z ₂ can be obtained:

in, is the coordinate value of the common associated point P _J in the workpiece coordinate system, is the coordinate value of the origin O ₃ (x ₃ , y ₃ , z ₃ ) of the measuring coordinate system in the tooling coordinate system; k is the scaling factor between the measuring coordinate system and the tooling coordinate system; is the coordinate value of P _J in the measurement coordinate system; is the coordinate offset of the reference point O ₂ (x ₂ , y ₂ , z ₂ ) of the workpiece coordinate system relative to the reference point O ₁ (x ₁ , y ₁ , z ₁ ) of the tool coordinate system,

According to the corresponding relationship between the measurement coordinate system X ₃ Y ₃ Z ₃ and the workpiece coordinate system X ₂ Y ₂ Z ₂ , the coordinate values of each measurement point in the measurement coordinate system can be converted into the workpiece coordinate value Coordinate values in the coordinate system to obtain point cloud data in multiple workpiece coordinate systems. Each of the point cloud data is a coordinate value of a measurement point. The _i -th ( _i =1, 2, 3, . A least squares method is used to fit the point cloud data under the multiple workpiece coordinate systems to generate a measurement model of the docking area.

Step 203: Obtain a theoretical model of the docking area.

A theoretical model of the docking area is obtained, where the theoretical model is a CAD model of the docking area of the tested aircraft component provided by the aircraft design department. By comparing and analyzing the measurement model and the theoretical model of the docking area of the aircraft part to be tested, the measured point cloud data is matched with the point cloud data of the theoretical model of the aircraft part, and the deviation value in the length direction is obtained as the gap value, the height The deviation value of the direction is the step difference value, and the actual gap and step difference of the docking area of the large aircraft components can be solved, and then the data of the docking gap and step difference of the large aircraft components can be seen through the host computer.

Step 204 : Obtain the docking gap and step difference of the docking region of the aircraft component under test according to the measurement model of the docking region and the theoretical model of the docking region.

The CAD theoretical model of the docking area is discretized to generate discrete point cloud data of the same order of magnitude as the point cloud data in the workpiece coordinate system; each of the discrete point cloud data is a coordinate value of a discrete point. The coordinate value of the _i -th ( _i =1, 2, 3, . . . ) discrete point includes a coordinate value li in the length direction and a coordinate value hi in the height direction. Then, based on the invariance of surface curvature rigid body transformation, the measured point cloud data is mapped and registered with the CAD theoretical model, and the deviation value in the length direction is the gap value, and the deviation value in the height direction is the step difference value. Specifically:

Matching a plurality of the measurement points in the docking area of the aircraft component under test with a plurality of the discrete points at the corresponding positions in the theoretical model to obtain a matching point pair of the measurement point and the discrete point. That is, the i-th discrete point and the i-th measurement point are a pair of matching points.

Acquire the coordinate values (L _i , H _i ) of the measurement point in the matching point pair under the workpiece coordinate system;

obtaining the coordinate values (l _i , h _i ) of the discrete points in the matching point pair;

Calculate the deviation value of the coordinate value of the measurement point in the workpiece coordinate system and the coordinate value of the discrete point in the length direction to obtain the docking gap of the docking area of the aircraft component under test; the calculation formula of the docking gap for:

Δl _i =L _i -l _i (8)

Among them, Δl _i is the deviation between the coordinate value of the i-th measurement point in the workpiece coordinate system and the coordinate value of the i-th discrete point in the length direction, that is, the i-th point in the docking area of the tested aircraft component Li is the coordinate value of the _i -th measurement point in the length direction; Li is the coordinate value of the _i -th discrete point in the length direction.

Calculate the deviation value of the coordinate value of the measurement point in the workpiece coordinate system and the coordinate value of the discrete point in the height direction, and obtain the step difference of the docking area of the tested aircraft component. The calculation formula of the step difference is:

Δh _i =H _{i -hi} (9)

Among them, Δh _i is the deviation between the coordinate value of the ith measurement point in the workpiece coordinate system and the coordinate value of the ith discrete point in the height direction, that is, the ith point in the docking area of the tested aircraft component H _i is the coordinate value in the height direction of the i-th measurement point; h _i is the coordinate value in the height direction of the i-th discrete point.

So far, the docking gap and step difference of all points in the docking area of the aircraft part under test can be obtained, so that the docking gap and step difference data of the entire docking area of the aircraft part 106 under test can be seen through the host computer 107, and then According to the docking gap and step difference of each point in the docking area, the docking attitude adjustment and edge trimming of the aircraft component 106 to be tested can be performed to realize the precise assembly of large aircraft components.

The docking process of aircraft components is approximately the transformation of rigid body space pose and attitude, and the error of the attitude control point can be obtained by mapping the actual measured value to the theoretical value, namely:

E=(R·D+T)-M (10)

Among them, E is the error matrix, R is the rotation transformation matrix, D is the measured data measured by the measuring head, T is the translation transformation matrix, and M is the theoretical value. The values in the matrices E, R, D, T, and M are all values in the tooling coordinate system.

in,

in the formula respectively represent the error of the nth (n=1, 2, ...) attitude adjustment control point in the x, y, and z directions, and n is the number of attitude adjustment control points.

In the formula, ε _x , ε _x , ε _x are the Euler angles of the component attitude transformation.

in the formula Respectively represent the coordinate values of the x, y, and z axes of the measured data of the nth attitude adjustment control point.

T=[T _x T _y T _z ] ^T (14)

T _x , _Ty , and T _z represent translation transformation matrices in three directions of x, y, and z, respectively.

in the formula The coordinate values of the x, y, and z axes representing the theoretical value of the nth attitude control point, respectively.

Since the accuracy requirements are symmetrical in the direction of each coordinate value, that is, ±S, the accuracy requirement matrix is:

in the formula Represents the accuracy of the nth attitude control point in the x, y, and z directions, respectively.

Use the least squares objective function:

Build the constraint model:

Among them, f represents the residual sum function, X represents the rotation matrix and translation matrix conforming to the attitude adjustment control point error, n represents the number of attitude adjustment control points, respectively represent the weights of the i-th attitude control point in the x, y, and z directions, Indicates the error in the x, y, and z directions of the i-th attitude control point. c _ix , c _iy , and c _iz represent constraint functions in the x, y, and z directions, respectively.

After obtaining X, the rotation matrix R and the translation matrix T are obtained, so that the best fitting position matrix F of the attitude control point is obtained according to the rotation matrix R and the translation matrix T:

F=R·D+T (20)

The position in the best fitting position matrix F is the position of the attitude adjustment control point under the target pose of the component docking, which meets the accuracy requirements of the attitude adjustment control point. Therefore, it can provide the attitude adjustment and trimming position of the large aircraft components, so as to realize the precise assembly of the large aircraft components.

It can be seen that the method for measuring the docking clearance and step difference of an aircraft component provided by the present invention is used to calculate the docking clearance of all points in the docking area of the aircraft component under test through the measurement data of the contour of the entire docking area of the aircraft component under test. and step difference, so that the docking gap and step difference data of the entire docking area of the aircraft component 106 under test can be seen through the host computer 107, effectively avoiding the defect of low measurement accuracy caused by only measuring local feature points and incomplete measurement data. , and then according to the docking gap and step difference of each point in the docking area, the docking attitude adjustment and trimming of the aircraft component 106 to be tested can be performed, so as to realize the precise assembly of large aircraft components.

The invention also provides a measurement system for the butt gap and step difference of aircraft components. FIG. 5 is a schematic structural diagram of a system for measuring the docking clearance and step difference of aircraft components provided by the present invention. Referring to Figure 5, the measurement system includes:

The contour data acquisition module 501 is used to obtain contour data of the docking area of the aircraft component under test; the contour data of the docking area of the aircraft component under test is a plurality of point cloud data measured by the measuring head; Point cloud data is the coordinate value of a measurement point in the measurement coordinate system.

a measurement model generation module 502, configured to generate a measurement model of the docking area according to the contour data of the docking area;

A theoretical model obtaining module 503, configured to obtain a theoretical model of the docking area;

A docking gap and step difference obtaining module 504 is configured to obtain the butt gap and step difference of the butt area of the tested aircraft component according to the measurement model of the butt area and the theoretical model of the butt area.

Wherein, the measurement model generation module 502 specifically includes:

The point cloud data acquisition unit is used to convert the coordinate value of each measurement point under the measurement coordinate system into the coordinate value under the workpiece coordinate system, and obtain point cloud data under multiple workpiece coordinate systems;

The measurement model generation unit is used for fitting the point cloud data under the plurality of workpiece coordinate systems by using the least square method to generate the measurement model of the docking area.

The docking gap and step difference obtaining module 504 specifically includes:

A discrete point cloud data generation unit, used for discretizing the theoretical model of the docking area, and generating discrete point cloud data of the same order of magnitude as the point cloud data in the workpiece coordinate system; each of the discrete point cloud data is one Coordinate values of discrete points;

The matching point pair acquisition unit is used to match a plurality of the measurement points in the docking area of the aircraft component under test with a plurality of the discrete points in the corresponding positions in the theoretical model, and obtain the difference between the measurement point and the discrete point. match point pairs;

a measuring point coordinate obtaining unit, used for obtaining the coordinate value of the measuring point in the matching point pair under the workpiece coordinate system;

a discrete point coordinate obtaining unit, configured to obtain the coordinate value of the discrete point in the matching point pair;

a docking gap calculation unit, used to calculate the deviation value of the coordinate value of the measurement point in the workpiece coordinate system and the coordinate value of the discrete point in the length direction, so as to obtain the docking gap of the docking area of the aircraft component under test;

The step difference calculation unit is used for calculating the deviation value of the coordinate value of the measurement point in the workpiece coordinate system and the coordinate value of the discrete point in the height direction, so as to obtain the step difference of the docking area of the tested aircraft component.

By adopting the measurement system for the butt gap and step difference of the aircraft parts provided by the present invention, the butt gap and the step difference of all points of the butt area of the aircraft part to be tested can be calculated through the measurement data of the outline of the entire butt area of the aircraft part to be tested. The step difference can effectively avoid the defect of low measurement accuracy caused by only measuring local feature points and incomplete measurement data, and then according to the docking gap and step difference of each point in the docking area, the aircraft component 106 to be tested can be docked for attitude adjustment and adjustment. Trimming for precise assembly of large aircraft components.

To sum up, the equipment, method and system for measuring the butt gap and step difference of aircraft components provided by the present invention have at least the following advantages:

1. A device, method and system for measuring the butt gap and step difference of aircraft components provided by the present invention, the accuracy of the devices and sensors used are all within the range required by the accuracy index, which can eliminate the early measurement deviation and improve the accuracy of the measurement data. To achieve high-precision measurement of the gap and step difference in the docking area in a large-scale space.

2. The device, method and system for measuring the docking clearance and step difference of aircraft parts provided by the present invention have low requirements on the movement accuracy and rigidity of the annular guide rail, and can be applied to the measurement of the docking area of aircraft parts of different models, with good performance. The versatility can reduce the overall measurement cost.

3. A device, method and system for measuring the butt gap and step difference of aircraft parts provided by the present invention, the measuring head adopts a line laser sensor, which greatly improves the measurement accuracy and efficiency of the butt gap and step difference of aircraft parts; The contour data of the docking area is processed for the adjustment of the docking attitude of the components and the trimming of the docking area. Compared with the traditional phase method, the measurement efficiency is high and the result usability is good; It can determine the position F for docking, attitude adjustment or trimming of large aircraft components, so as to achieve precise assembly of aircraft components.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

In this paper, specific examples are used to illustrate the principles and implementations of the present invention. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present invention; meanwhile, for those skilled in the art, according to the present invention There will be changes in the specific implementation and application scope. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (8)

1. the measurement equipment of an aircraft component docking gap and step difference, it is characterized in that, described measurement equipment comprises positioning device, measuring device and upper computer; Described positioning device comprises positioning tool; Described measuring device comprises ring track, measurement head, measuring head drive and ring track drive; The aircraft component to be tested is mounted on the positioning device; The ring track is installed on the positioning tool, and the measurement head is installed on the ring track; the ring track is used to ensure that there is a preset distance between the measurement head and the aircraft component to be measured; The measuring head driving device is installed on the ring track, the measuring head driving device is connected with the measuring head, and is used for driving the measuring head to move along the ring track; The ring track driving device is installed on the positioning tool, the ring track driving device is connected with the ring track, and is used for driving the ring track to perform translational movement on the positioning tool; The measuring head is connected to the host computer; the measuring head is used to measure the contour data of the docking area of the aircraft component under test; the host computer is used to calculate the measured contour data according to the contour data of the docking area Butt gaps and steps in the docking area of aircraft components; The measuring device also includes a calibration block and a laser tracking device; The calibration block is installed on the bottom of the positioning tool; the laser tracking device is installed on the top of the ring track; the calibration block and the laser tracking device are used to calibrate the position of the ring track and the measuring head; The calibration block is a trapezoidal block structure, and the measurement head is calibrated through three-point measurement; the number of the calibration blocks is multiple; and the multiple calibration blocks are installed at the bottom of the positioning tool at equal intervals. 2 . The equipment for measuring the butt gap and step difference of aircraft components according to claim 1 , wherein the measuring head is a linear structured light vision sensor. 3 . 3 . The measuring equipment for docking clearance and step difference of aircraft components according to claim 2 , wherein the positioning device further comprises an attitude adjustment tool; the attitude adjustment tool is located on one side of the positioning tool; A roller is installed at the bottom of the attitude tool; the attitude adjustment tool is used to perform butt attitude adjustment and trimming of the tested aircraft component according to the butt gap and step difference. 4. a method for measuring the butt gap of aircraft parts and step difference, characterized in that, the measurement method is applied to the measuring equipment of the aircraft part butt gap and step difference described in any one of claims 1-3; the measurement Methods include: Obtain the contour data of the docking area of the aircraft component under test; generating a measurement model of the docking area according to the contour data of the docking area; obtaining a theoretical model of the docking region; According to the measurement model of the butt region and the theoretical model of the butt region, the butt gap and step difference of the butt region of the tested aircraft component are obtained. 5. the measuring method of aircraft part docking clearance and step difference according to claim 4, is characterized in that, described obtaining the contour data of the docking area of tested aircraft part, specifically comprises: Obtain the contour data of the docking area of the tested aircraft part; the contour data of the docking area of the tested aircraft part is a plurality of point cloud data measured by the measuring head; each of the point cloud data is a measurement point at Measure the coordinate value in the coordinate system. 6. The method for measuring docking clearance and step difference of aircraft components according to claim 5, wherein the generating the measurement model of the docking area according to the contour data of the docking area specifically comprises: Convert the coordinate value of each measurement point under the measurement coordinate system into the coordinate value under the workpiece coordinate system, and obtain point cloud data under multiple workpiece coordinate systems; A least squares method is used to fit the point cloud data under the multiple workpiece coordinate systems to generate a measurement model of the docking area. 7. The method for measuring the butt gap and step difference of aircraft parts according to claim 6, wherein the measurement model of the aircraft part to be tested is obtained according to the measurement model of the butt area and the theoretical model of the butt area. The docking gap and step difference in the docking area, including: Discretize the theoretical model of the docking area to generate discrete point cloud data of the same order of magnitude as the point cloud data under the workpiece coordinate system; each of the discrete point cloud data is a coordinate value of a discrete point; Matching a plurality of the measurement points in the docking area of the aircraft component under test with a plurality of the discrete points in the corresponding positions in the theoretical model to obtain matching point pairs of the measurement points and the discrete points; Obtain the coordinate value of the measurement point in the matching point pair under the workpiece coordinate system; obtaining the coordinate values of the discrete points in the matching point pair; Calculate the deviation value of the coordinate value of the measurement point in the workpiece coordinate system and the coordinate value of the discrete point in the length direction to obtain the docking gap of the docking area of the aircraft component under test; Calculate the deviation value of the coordinate value of the measurement point in the workpiece coordinate system and the coordinate value of the discrete point in the height direction, and obtain the step difference of the docking area of the tested aircraft component. 8. A measurement system for the butt gap and step difference of aircraft parts, characterized in that, the measurement system is applied to the measurement equipment of the aircraft part butt gap and step difference according to any one of claims 1-3; the measurement The system includes: The contour data acquisition module is used to obtain the contour data of the docking area of the tested aircraft component; a measurement model generation module for generating a measurement model of the docking area according to the contour data of the docking area; a theoretical model acquisition module for acquiring the theoretical model of the docking area; A butt gap and step difference obtaining module is used to obtain the butt gap and step difference of the butt area of the tested aircraft component according to the measurement model of the butt area and the theoretical model of the butt area.