CN105136094A - Curved surface auxiliary measuring device and curved surface coordinate system determining method for symmetrical double-curvature panels - Google Patents

Abstract

A curved surface auxiliary measuring device and a curved surface coordinate system determining method for symmetrical double-curvature panels relate to the field of aviation and aerospace manufacturing machinery. The device and the method are provided to solve the problem that the existing curved surface auxiliary measuring device and the coordinate system determining method are complex and need large amount of calculation. According to the technical scheme, the upper and lower end faces of a base are kept parallel to each other, two intersecting side walls on the base are respectively equipped with a first fixed seat, the remaining two side walls on the base are respectively equipped with a boss, each boss is provided with two internal threaded holes, and one end of each bolt is fixedly connected to a second fixed seat after passing through the corresponding internal threaded hole. The method comprises the following steps: step 1, putting and fixing a curved piece in the device; step 2, acquiring point cloud data; and step 3, establishing a coordinate system, and using Imageware software to process the point cloud data. The curved surface auxiliary measuring device and the curved surface coordinate system determining method of the invention are used in auxiliary measurement of the curved surface of a symmetric double-curvature panel.

Description

A curved surface auxiliary measuring device and a method for determining a curved surface coordinate system for a symmetrical double-curvature plate

technical field

The invention relates to a curved surface auxiliary measuring device and a curved surface coordinate system determination method for a symmetrical double-curvature plate, and relates to the field of aerospace manufacturing machinery.

Background technique

Double-curvature parts are mostly used in the aerospace industry, such as aircraft skins, double-curvature panels, etc., and also occupy a certain proportion in the civilian field. The radius of curvature of double-curvature parts changes in different directions, so their complex geometric profiles increase the difficulty of measurement. Sheet metal will rebound after bending, and springback is a key factor affecting the forming accuracy of sheet metal parts. In order to quantitatively study the springback, it is necessary to establish the center of symmetry of the surface part, and set the point to keep its position before and after the springback. A coordinate system can be established based on the center point of symmetry, and the springback of the unloaded curved surface piece relative to the unloaded curved surface piece can be evaluated.

The establishment of the coordinate system of the surface part needs to obtain the coordinate origin and the vertical relationship of the three-dimensional direction. For the surface with obvious symmetrical features, it is difficult to establish the coordinate origin and the three-dimensional direction (such as x-axis, y-axis and z-axis) only from the obtained surface point cloud. vertical relationship. An existing patent introduces a transformation method between a scanner coordinate system and an engineering survey coordinate system. However, the transformation method is cumbersome and requires a large amount of calculation. At the same time, it is necessary to set a target to determine the positional relationship of the measured contour, and the test work is heavy.

Contents of the invention

The object of the present invention is to provide a curved surface auxiliary measuring device and a method for determining a curved surface coordinate system for symmetrical double-curvature plates, so as to solve the problems that the current curved surface auxiliary measuring device and the method for determining the coordinate system are cumbersome and require a large amount of calculation.

The technical scheme that the present invention takes for solving the problems of the technologies described above is:

Device scheme: the device includes a base, two first fixed seats, two second fixed seats, two bosses and four bolts, the upper and lower end surfaces of the base are kept parallel, and the intersecting two side walls on the base are respectively Equipped with the first fixing base, bosses are provided on the remaining two side walls of the base, and each boss has two internally threaded holes, and one end of each bolt passes through the internally threaded holes and is fixed with the second The seat is fixed.

Method scheme: Step 1. Place the curved surface piece on the horizontal end surface of the base, so that the adjacent side walls of the curved surface piece are in close contact with the horizontal section sidewall of the first fixed seat, and make the horizontal section side wall of the second fixed seat The curved surface part is in contact with the other adjacent side wall, so that the bolt passes through the internal thread hole of the boss and contacts the rear end faces of the vertical sections of the two second fixing seats, and the bolt is rotated so that the front end surfaces of the vertical sections of the second fixing seats Keep in close contact with curved parts;

Step 2. Obtain point cloud data, use the probe of the portable measuring instrument to scan the curved surface of the curved surface, and simultaneously scan the contour of the front end surface of the vertical section of the second fixed seat, the contour of the front surface of the vertical section of the first fixed seat and the level of the base End face, to obtain the corresponding point cloud data;

Step 3: Construct the coordinate system, use Imageware software to process the point cloud data, use the software fitting function to obtain the reference surfaces of the five end faces, and use the software intersection function to obtain the horizontal end face of the base and the front face of the vertical section of the first fixed seat of the base The two intersection lines, the two intersection lines between the horizontal end surface of the base and the front end surface of the vertical section of the second fixed seat, according to the function of the section line, the member quadrilateral and the midpoint of each side are obtained, and the two opposite midpoints are respectively connected to obtain two The two straight lines are the x-axis and the y-axis in the horizontal end surface of the base. The perpendicular line of the x-axis and the y-axis is established through the intersection of the two straight lines. The vertical line is the z-axis, and the z-axis and the point cloud of the surface part The intersection point is the origin of symmetry of the curved surface. Moving the x-axis and y-axis to the origin of symmetry along the z-axis constitutes the three-dimensional coordinate system of the curved surface.

The present invention has the following beneficial effects: 1. The auxiliary measuring device of the present invention has small geometrical dimensions, is easy to operate, and can realize the measurement of various curved surfaces with symmetrical shapes. 2. The curved surface parts fastened by the auxiliary measuring device can be obtained by the contact or non-contact measuring instrument to obtain the point cloud of the surface contour of the part and the reference surface. 3. Through the Imageware software, the point cloud can be processed, and the symmetrical origin and coordinate system of the surface can be quickly obtained according to the geometric vertical relationship of the reference surface.

Description of drawings

Fig. 1 is a perspective view of the overall auxiliary measuring device and the curved surface part to be measured.

Detailed ways

Specific Embodiment 1: This embodiment is described in conjunction with FIG. 1. The device of this embodiment includes a base 1, two first fixing seats 2, two second fixing seats 3, two bosses 4 and four bolts 5. The upper and lower ends of the base 1 are kept parallel, the intersecting side walls of the base 1 are respectively equipped with first fixing seats 2, and the remaining two side walls of the base 1 are respectively provided with bosses 4, and each boss 4 There are two internally threaded holes 4-1, and one end of each bolt 5 passes through the internally threaded holes 4-1 and is affixed to the second fixing seat 3.

Specific Embodiment 2: This embodiment is described with reference to FIG. 1 . The cross-sectional shape of the first fixing seat 2 and the second fixing seat 3 in this embodiment is L-shaped, and this structure is convenient for manufacture. Other implementation manners are the same as the specific implementation manner 1.

Specific Embodiment 3: This embodiment is described with reference to FIG. 1 . In this embodiment, two first fixing bases 2 are fixedly connected and the angle between them is 90°. This structure is easy to operate during use. Other implementation manners are the same as the specific implementation manner 1.

Embodiment 4: This embodiment is described in conjunction with FIG. 1. This embodiment includes the following steps: Step 1. Place the curved surface member 6 on the horizontal end surface of the base 1, and make the adjacent two side walls of the curved surface member 6 and the first fixed surface. The side wall of the horizontal section of the seat 2 is in close contact, so that the side wall of the horizontal section of the second fixed seat 3 is in contact with the other adjacent side wall of the curved surface member 6, so that the bolt 5 passes through the internal threaded hole 4-1 of the boss 4, and contacts The rear end surfaces of the vertical sections of the two second fixed seats 3, the rotation bolt 5 makes the front end surfaces of the vertical sections of the second fixed seats 3 keep in close contact with the curved surface member 6;

Step 2, obtain point cloud data, utilize the probe of portable measuring instrument to scan the curved surface of curved surface part 6, scan the profile of the front end face of the vertical section of the second holder 3, the outline and the base of the front end face of the vertical section of the first holder 2 simultaneously. The horizontal end surface of seat 1, and obtain the corresponding point cloud data;

Step 3, form a coordinate system, use Imageware software to process point cloud data, use the software fitting function to obtain the reference surfaces of the 5 end faces, use the software intersection function to obtain the horizontal end face of the base 1 and the vertical position of the first fixed seat 2 of the base 1 The two intersection lines of the front end face of the segment, the two intersection lines of the horizontal end face of the base 1 and the vertical segment front end face of the second fixed seat 3, according to the section line function, the component quadrilateral and the midpoint of each side are obtained, and the pair of pairs are connected respectively. Obtain two straight lines toward the midpoint, the two straight lines are the x-axis and the y-axis in the horizontal end surface of the base 1, pass through the intersection of the two straight lines to establish a perpendicular line between the x-axis and the y-axis, the vertical line is the z-axis, and the z-axis The point of intersection with the point cloud of the surface part is the origin of symmetry of the surface. Moving the x-axis and y-axis to the origin of symmetry along the z-axis direction constitutes the three-dimensional coordinate system of the surface part.

Claims (4)

1. A curved surface auxiliary measuring device for a symmetrical double-curvature plate, characterized in that the device comprises a base (1), two first fixed seats (2), two second fixed seats (3), two a boss (4) and four bolts (5), the upper and lower end surfaces of the base (1) are kept parallel, the intersecting side walls of the base (1) are respectively equipped with a first fixed seat (2), and the base (1) 1) Bosses (4) are respectively provided on the remaining two side walls, and each boss (4) has two internally threaded holes (4-1), and one end of each bolt (5) passes through the inner The threaded hole (4-1) is fixedly connected with the second fixing seat (3) behind. 2. A curved surface auxiliary measuring device for symmetrical double-curvature plates according to claim 1, characterized in that the cross-sectional shape of the first fixing seat (2) and the second fixing seat (3) is L-shaped. 3. A curved surface auxiliary measuring device for a symmetrical double-curvature plate according to claim 1 or 2, characterized in that the two first fixing seats (2) are affixed and the angle formed by the two front faces is 90° . 4. Utilize the curved surface auxiliary measuring device for symmetrical double-curvature plate according to claim 1 to the method for determining the curved surface coordinate system, characterized in that Step 1. Place the curved surface part (6) on the horizontal end surface of the base (1), so that the adjacent side walls of the curved surface part (6) are in close contact with the side walls of the horizontal section of the first fixed seat (2), so that the second The side wall of the horizontal section of the second fixed seat (3) is in contact with the other adjacent side wall of the curved surface piece (6), so that the bolt (5) passes through the internal threaded hole (4-1) of the boss (4) and contacts the two The rear end surface of the vertical section of the second fixed seat (3), rotating the bolt (5) makes the front end surface of the vertical section of the second fixed seat (3) keep in close contact with the curved surface part (6); Step 2: Obtain point cloud data, use the probe of the portable measuring instrument to scan the curved surface of the curved surface part (6), and scan the contour of the front end face of the vertical section of the second fixed seat (3) and the vertical section of the first fixed seat (2) simultaneously. The profile of the front face and the horizontal end face of the base (1) obtain corresponding point cloud data; Step 3, form a coordinate system, use Imageware software to process point cloud data, use the software fitting function to obtain the reference surfaces of the 5 end faces, use the software intersection function to obtain the horizontal end face of the base (1) and the first fixation of the base (1) The two intersection lines of the front end face of the vertical section of the seat (2), the two intersection lines of the horizontal end face of the base (1) and the front end face of the vertical section of the second fixed seat (3), according to the section line function, the quadrilateral of the component is obtained and The midpoints of each side are respectively connected to the opposite midpoints to obtain two straight lines, the two straight lines are the x-axis and y-axis in the horizontal end surface of the base (1), and the x-axis and y-axis are established through the intersection of the two straight lines The vertical line is the z-axis, and the intersection point of the z-axis and the point cloud of the surface part is the origin of symmetry of the surface. Moving the x-axis and y-axis to the origin of symmetry along the z-axis constitutes the three-dimensional coordinate system of the surface part.