JPH0575322B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a contact-type measuring instrument for measuring the three-dimensional position caused by machining errors at the center of a measured object, and particularly relates to a contact-type measuring instrument that is highly accurate, simple, and inexpensive. The present invention relates to a three-dimensional position detection device.

[Prior art] Conventionally, there is a device that uses image processing using a television camera to measure the three-dimensional position centered on the object to be measured, but the environment setting and calculation processing are complicated and the device is expensive. .

For example, when measuring machining errors in bolt holes of an object to be measured, the object to be measured is set on a mechanical surface plate having a perfectly horizontal surface via a support stand. Finely adjust the support using a dial gauge, etc. to maintain the horizontal reference line of the object to be measured horizontally. The position of the center of the bolt hole in the vertical direction, that is, in the Z direction, is measured from the surface plate, and the x and y directions also include the reference Z axis and are perpendicular to each other in the x and y planes (e.g., cross section, longitudinal section). Although it can be determined by actually measuring the dimensions from , the dimension measurement requires skill and requires several calculations, and the occurrence of errors is unavoidable.

[Problem that the invention seeks to solve]

Three-dimensional position measurement of an object to be measured requires expensive equipment such as image processing, and actual measurement on a surface plate requires skill and is difficult to obtain accuracy.

An object of the present invention is to provide a three-dimensional position detection device that is highly accurate, has a simple structure, and is inexpensive for measuring the three-dimensional position of an object to be measured.

[Means for solving problems]

In order to achieve the above object, the present invention provides a rod having a means for attaching the rod with the center of the tip aligned with the center of the object to be measured, and a linear ball that slidably supports the rod at a position separated by a predetermined length from the tip. A bearing, a ball joint for inserting the linear ball bearing toward the center of the sphere and passing through the rod, an upper surface member having a spherical recess into which the ball joint is rotatably fitted, and the upper surface member. A case consisting of a hollow cylindrical body forming an end face, a spring provided between the rod and the upper surface member for cushioning the sliding and rotational movement of the rod, and a circular plate housed in the case and at the rear end of the rod. A light source whose center part is fixed, a light source which is installed in the center part and emits slit light through slits provided in the radial direction in the disc, and a light source which is arranged on the inner surface of the side wall of the case and receives the slit light. It is configured to detect the three-dimensional position of the object to be measured by processing the light spot position of each position detection light receiving element.

[Effect]

According to the present invention, the center of the tip of the rod of the three-dimensional position detection device is mounted so that it coincides with the center of the object to be measured, so that the rod is placed in a reference position and moves three-dimensionally, and at the same time the rear end of the rod is aligned with the center of the object to be measured. A fixed light source moves three-dimensionally within the case. The light emitted from within the center of the light source becomes slit light through the radial slits of the disc, and is projected onto the position detection light receiving element installed on the side wall of the case, by calculating the position of each light point. As a result, data for calculating the three-dimensional position of the object to be measured with the spherical center of the ball joint as the origin of coordinates can be obtained.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, the rod 7 has a means for swingably attaching it with a self-aligning end 14 provided via a small spring 13, for example, with the center of the tip aligned with the center Q of the object to be measured. , a linear ball bearing 5 that extends a predetermined length from the tip and slidably supports the rod 7; a ball joint 4 that inserts the linear ball bearing 5 toward the center of the sphere and penetrates the rod 7; A case 12 consisting of an upper surface member 16 having a spherical recess that rotatably supports the ball joint 4, and a hollow cylindrical body whose end surface is formed by the upper surface member 16.
and a plurality of inclination angle stoppers 10 provided on the upper surface of the upper surface member 16 to limit the inclination angle of the rod 7;
A plurality of stoppers 8 and 9 are provided on the rod 7 to limit the sliding direction of the rod 7 and sandwich the upper surface member 16.
and cushions the sliding and rotation of the rod 7.
A spring 6 provided between the upper surface member 16 and the upper surface member 16
and a light source body 1 which is housed in a case 12 and has a central portion of a disc fixed to its rear end at right angles to the rod 7.
1, and a light source (LED) housed at point P in the center, connected to the electrical cord 15, and emitting slit light 3 through a slit provided in the radial direction within the disk.
1, and at least three position detection light receiving elements 2a to 2c disposed on the inner surface of the side wall of the case 12 to receive the slit light 3.As shown in FIG. ~2c
The light spot positions A to C are processed by calculation formula (1) to detect the three-dimensional position of the center Q of the object to be measured with the spherical center O of the ball joint 4 as the origin of coordinates.

In addition, the stoppers 8, 9 and 10 are connected to the light source 1.
1 collides with the inner surface of the case 12, or the light source 11
The slit light 3 from the position detection light receiving elements 2a to 2
The small spring 13 and the spring 6 are used to hold the tip of the rod 7 at the initial point _Q0 .

For example, to three-dimensionally determine the machining error of a bolt hole (Δx, Δy, Δz) at point Q, as the tip of rod 7 moves to point 11 moves three-dimensionally, and the slit light 3 is projected onto the position detection light receiving elements (for example, PSD) 2a to 2c by the slit groove or lens. three
PSD (2a, 2b, 2c) is one-dimensional PSD and A/V
Based on these light spot positions obtained through converters, amplifiers, calculations, etc., the three-dimensional position of point Q based on the O-xyz coordinates is calculated by computer processing using the calculation formula (1). be able to. Then, the case 12 is moved by an automatic control mechanism, etc., and the Qr of the design point is
It is sufficient to move point Q to the point via the self-aligning end 14.

Note that the three-dimensional position of the object to be measured is based on the coordinate origin O, and the relative position between the dimensional reference line of the object to be measured and the origin O should be confirmed as necessary. Further, the mounting angles between the rod 7, the light source body 11, and the position detection light receiving elements 2a to 2c are set at right angles and parallel to each other, and means for preventing rotation of the case 12 with respect to the rod 7 can be provided. Errors due to deviations in the relative positions of should be known in advance and the calculation formula (1) corrected.

Next, the arithmetic expression (1) will be explained with reference to FIG.

As shown in FIG. 3, the vectors and coordinates at each point are as follows.

OQ→=(x, y, z) OA→=(ax, ay, az) OB→=(bx, by, bz) OC→=(cx, cy, cz) OP→=(xp, yp, yz) x=−R・xp y=−R・yp z=−R・zp ………(1) Here, R=OQ/OP=PQ−OP/OP = constant =√ ² + ² + ² To find xp, yp, and zp from point positions A, B, and C, xp=S・|A ₁ | yp=S・|A ₂ | zp=S・|A ₃ | Here, S=|A| /｜A ₁ ｜ ² +｜A ₂ ｜ ² +｜A ₃ ｜ ² A=ax bx cx ay by cy az bz cz Ai is the i-th column of A replaced with column vector [111] ^T.

〔Effect of the invention〕

According to the present invention, by aligning the center of the tip of the rod of the three-dimensional position detection device with the center of the object to be measured, the light source body moves three-dimensionally together with the rod, and the tip position of the light source body is detected by the position detection light receiving element. As a result, the three-dimensional position of the object to be measured with the origin at point O can be detected through arithmetic processing, and measurement can be performed with high accuracy using a simple and inexpensive device.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the present invention, FIG. 2 is a cross-sectional view of FIG. 1, and FIG. 3 is an optical path diagram of the apparatus of the present invention. 1...Light source, 2a-2c...Position detection light receiving element, 3
...Slit light, 4...Ball joint, 5...Linear ball bearing, 6...Spring, 7...Rod, 11...Light source body, 12...Case, 16...Top surface member.

Claims (1)

[Claims] 1. A rod having means for attaching the rod with the center of the tip aligned with the center of the object to be measured, a linear ball bearing that slidably supports the rod at a position separated from the tip by a predetermined distance, and the linear ball bearing. A ball joint inserted toward the center of a sphere and passing through the rod, an upper surface member having a spherical recess into which the ball joint is rotatably fitted, and a hollow cylindrical body in which the upper surface member forms an end surface. a case consisting of a case, a spring provided between the rod and the upper surface member for cushioning the sliding and rotation of the rod, and a center portion of a disc housed in the case and at the rear end of the rod. a fixed light source body, a light source installed in the center and emitting slit light through slits provided in the radial direction in the disc, and a light source disposed on the inner surface of the side wall of the case to receive the slit light. A three-dimensional position detection device comprising at least three position detection light-receiving elements, and detecting the three-dimensional position of the object by calculating the light spot position of each of the position detection light-receiving elements. .