CN105136094B - A kind of surface coordinates system based on symmetric double curved plate curved surface aided measurement device determines method - Google Patents

Abstract

A curved surface auxiliary measuring device and a curved surface coordinate system determination method for a symmetrical double curvature plate relate to the field of aerospace manufacturing machinery. The device and the method solve the problems that the current auxiliary surface measuring device and the method for determining the coordinate system are cumbersome and the amount of calculation is large. Solution: the upper and lower ends of the base are kept parallel, the intersecting side walls of the base are respectively equipped with first fixing seats, and the remaining two side walls of the base are respectively provided with bosses, and each boss has inner two one end of each bolt passes through the inner threaded hole and is affixed to the second fixing seat. Method scheme: step 1, place the surface piece in the device for fixation; step 2, obtain point cloud data; step 3, form a coordinate system, and use Imageware software to process point cloud data. The invention is used for the auxiliary measurement of the curved surface of the symmetrical double curvature plate.

Description

Determination of Curved Surface Coordinate System Based on Auxiliary Measuring Device of Symmetrical Double Curvature Plate Surface method

technical field

The invention relates to a method for determining a curved surface coordinate system based on an auxiliary measuring device for a symmetrical double curvature plate curved surface, 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 purpose of the present invention is to provide a method for determining the coordinate system of a curved surface based on an auxiliary measuring device for a curved surface of a symmetrical double-curvature plate, so as to solve the problems that the auxiliary measuring device for a curved surface 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 of 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 intercept line, construct a quadrilateral and obtain the midpoint of each side, respectively connect the opposite midpoints 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 description

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 section, the two intersection lines of the horizontal end face of the base 1 and the vertical end face of the second fixed seat 3, according to the function of the section line, construct a quadrilateral and obtain the midpoint of each side, and connect the two pairs of 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 (1)

1. a kind of surface coordinates system based on symmetric double curved plate curved surface aided measurement device determines method, the curved surface auxiliary is surveyed Amount device includes pedestal (1), two the first fixed seats (2), two the second fixed seats (3), two boss (4) and four bolts (5), pedestal (1) upper and lower end face keeping parallelism, the first fixed seat (2), pedestal are respectively provided with the two side intersected on pedestal (1) (1) boss (4) is respectively provided with upper remaining two side walls, each boss (4) is provided with two internal thread holes (4-1), each bolt (5) one end is affixed with the second fixed seat (3) afterwards through internal thread hole (4-1), the first fixed seat (2) and the second fixed seat (3) Shape of cross section be L-shaped, the angle that two the first fixed seats (2) are affixed and the two front end face is formed is 90 °,

It is characterized in that：It the described method comprises the following steps：

Step 1: curved-surface piece (6) is placed on the horizontal end face of pedestal (1), make the adjacent two side of curved-surface piece (6) solid with first The horizontal segment side wall of reservation (2) is in close contact, and makes the horizontal segment side wall and curved-surface piece (6) another adjacent wall of the second fixed seat (3) Contact, bolt (5) is passed through the internal thread hole (4-1) of boss (4), and contact the rear end of two the second fixed seat (3) vertical sections Face, swivel bolt (5) make the front end face of the second fixed seat (3) vertical section and curved-surface piece (6) keep being in close contact；

Step 2: obtain cloud data, using the curved surface of the scanning probe curved-surface piece (6) of portable surveying instrument, while the is scanned The profile, the profile of the first fixed seat (2) vertical section front end face and the level of pedestal (1) of two fixed seats (3) vertical section front end face End face, obtain corresponding cloud data；

Step 3: forming coordinate system, using Imageware software processing cloud datas, 5 ends of gain-of-function are fitted using software The plane of reference in face, the first fixed seat (2) vertical section of the horizontal end face of gain-of-function pedestal (1) and pedestal (1) is intersected using software Two intersections of two intersections of front end face, the horizontal end face of pedestal (1) and the second fixed seat (3) vertical section front end face, according to cut Line function, build quadrangle and obtain the midpoint of each edge, connect respectively to obtaining two straight lines to midpoint, two straight lines are X-axis and y-axis in pedestal (1) horizontal end face, cross the vertical line that two straight-line intersections establish x-axis and y-axis, and vertical line is Z-axis line, z-axis and the intersection point of curved-surface piece point cloud are the symmetrical origin of curved surface, x-axis and y-axis are moved into symmetrical origin along the z-axis direction, then Constitute the three-dimensional system of coordinate of curved-surface piece.