JPS6131905A - Three-dimensional measuring instrument - Google Patents

Abstract

PURPOSE:To measure the position of a body to be measured with precision simultaneously with its shape by providing an arithmetic circuit which calculates and measures the three-dimensional position of each irradiation point on the surface of the object body on the basis of positions of respective irradiation points on image pickup surfaces of both image pickup means. CONSTITUTION:A couple of image pickup means S1 and S2 composed of a CCD type linear image sensor which picks up an image of the body to be measured (work) are provided at the right-end and left-end parts in a moving body 6. This device is equipped with the arithmetic circuit which calculates and measures the three-dimensional position of each irradiation point on the surface of the object body on the basis of positions of respective irradiation positions on the image pickup surfaces of both image pickup means S1 and S2. Therefore, both image pickup means S1 and S2 move to right and left and both image pickup means S1 and S2 and a light source LS move forth and back to irradiate the respective irradiation points on the entire surface of the object body, and while the three- dimensional position of each irradiation point is calculated and measured continuously to shorten the measurement time, the shape and position of the object body are measured simultaneously and precisely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a three-dimensional measuring device that derives the three-dimensional position of each point on the surface of an object to be measured and measures the shape of the object.

[Prior art]

Conventionally, methods for calculating the three-dimensional position of each point on the surface of the object to be measured and measuring the shape of the object to be measured include the contact method, which measures the shape of the object by bringing a sensing probe into contact with the object. , a stereo photography method in which the same object is imaged simultaneously by two cameras and the common points of both images are determined to measure the shape of the object to be measured. The hair aletopography method is based on which the shape of the object to be measured is measured, and the object to be measured is irradiated with a vertically elongated slit light, the irradiated area is imaged with a television camera, and the characteristic points of the image are determined to determine the shape of the object to be measured. There are non-contact methods such as optical cutting methods that measure the shape of objects, and these methods are widely applied as object recognition technologies for industrial robots and various inspection devices.

However, the contact method described above has the disadvantage that measurement takes a long time, and even in the case of a non-contact method, the position of the object, that is, the position in any coordinate system, can only be determined by recognizing the shape of the object. Since the coordinates are not directly measured, in order to determine the position of the object to be measured, the target point is determined from the obtained image, and then the position, or coordinates, of the determined point is calculated.

The calculations are time consuming, and the resolution of the measurement equipment used to implement these methods is very low. The method has the disadvantage that it cannot accurately recognize the shape of the object to be measured and the state of surface irregularities, and lacks reliability, and is therefore insufficient for measuring the shape of the object to be measured.

[Purpose of the invention]

This invention was made with the above points in mind,
The purpose is to be able to accurately measure the three-dimensional position of each point on the surface of an object to be measured in a short time.

[Structure of the invention]

The present invention includes a pair of imaging means that are provided movably in the left-right direction and in the front-rear direction and take images of the object to be measured; a light source that sequentially irradiates slit light to a plurality of locations on a line in the horizontal direction on the surface of the object to be measured within an overlapping field of view, a movement of both the imaging means in the left-right direction, and a movement of the imaging means and the light source in the front-rear direction; a processing circuit that processes images of each of the irradiation points of each of the slit lights by the two imaging means due to the movement of the slit light, and derives the position of each of the irradiation points on the imaging surfaces of the two imaging means; The three-dimensional measuring device is provided with an arithmetic circuit that calculates and measures a three-dimensional position of each of the irradiation points on the surface of the object to be measured based on the positions of the two imaging planes.

〔Effect of the invention〕

Therefore, according to the three-dimensional measurement apparatus of the present invention, a pair of imaging means and a light source that irradiates slit light within the overlapping field of view of both the imaging means are provided, and images of each irradiation point on the surface of the object to be measured are processed and both A processing circuit is provided for deriving the position of each irradiation point on the imaging surface of the imaging means, and an arithmetic circuit is provided for calculating the actual three-dimensional position of each irradiation point based on the position of each irradiation point on both of the imaging surfaces. By moving both imaging means in the left-right direction and moving both imaging means and the light source in the front-back direction, each irradiation point on the entire surface of the object to be measured can be irradiated, and each irradiation point can be illuminated in three dimensions. It is possible to reduce the measurement time by continuously calculating and measuring the position, and the shape and position of the object to be measured can be measured simultaneously with high precision, which is very practical.

[Embodiment] Next, the present invention will be described in detail with reference to drawings showing one embodiment thereof.

First, in FIG. 1, fi+ is a first guide body provided at a predetermined height on a pedestal and is elongated in the front and back direction, and (2) is a first guide body that is long in the front and back direction.
The second part, which will be described later, is attached to the rear end on the guide body ill.
The first motor (3) for moving the guide body has its lower left end screwed onto the first feed screw whose both ends are fixed to the rotating shaft and bearing of the first motor 12), so that it can move freely in the front and back direction. The second guide body (4), which is long in the left-right direction and is provided in Expandable bellows-shaped envelope, i5+, +5 movable second heater and bearing for moving the moving body (to be described later) attached to the left and right ends of the second guide body (3), (6) is the lower surface It is a moving body in the form of a casing with an opening, and an actuating body (6)' is integrally formed at the upper left end of the rear side, and both ends are locked to the second movable member (5) and the bearing (6)'. The operating body [6]' is screwed into the second feed screw, and the movable body (6) can move in the left and right direction in front of the second guide body (3), and the inside of the movable body (6) A pair of imaging means (not shown) consisting of a CCD type linear image sensor for imaging an object to be measured (not shown) (hereinafter referred to as a work) are fixedly provided at the left end and right end of the A light source (not shown) consisting of a laser, a xenon lamp with a circular slit, etc. is provided in the center of the body (6) and is rotatable by a stepping motor.

Next, in FIG. 2 showing a processing circuit that processes signals from both of the image pickup means, (7) indicates that a plurality of light receiving elements are one
an imaging surface of the one imaging means that is arranged dimensionally and images the irradiation point of the spot light through the condensing lens of the one imaging means, and outputs an image signal obtained by combining the imaging signals from the respective light receiving elements; , (8) is a slicer that slices the image decoded analog signal from the imaging surface (7) and converts it into a digital image signal, (9) is the slice level setting device of the slicer (8), and αQ is the ), (11) is a setting switch for setting the unnecessary parts, and (121 is a masking circuit for erasing the unnecessary part of the image signal from the sliced imaging surface (7).) The address counter 03) counts the addresses corresponding to the light-receiving elements of the counter 121.
(141 is a storage unit that stores the address data counted by the counter Q21, 05 is an interface that transfers the data stored in the output terminal (from the IQ to the storage unit α4), and the slicer ( 8)
, level setter (9), masking circuit α0. Setting switch I11.

The counter α22 display unit αJ, the storage unit (141 and the interface Q5) constitute a processing circuit (17a) of one of the imaging means, and likewise a processing circuit (17b) of the other imaging means. There is.

Furthermore, in FIG. 3 showing the arithmetic circuit, Q8] calculates the coordinates of the spot light irradiation point on the workpiece in an arbitrary XYZ coordinate system based on the address data transferred from both processing circuits (17a) and (17b). The calculation unit to derive, (
19) is a display section, which is adapted to display the coordinates of the irradiation point derived by the arithmetic section tll19.The arithmetic section (1&) and the display section (19) constitute an arithmetic circuit consisting of a computer or the like. , both processing circuits (17a)
, (17b) and the arithmetic circuit (17b) constitute an image processing means (1).

Now, as shown in Figure 1, the X, Y, Z coordinates of the XYZ coordinate system whose origin is an arbitrary point in each of the left, right, up, down, and back directions.
When measuring the shape of the workpiece by taking each axis of the workpiece and deriving the three-dimensional position of each point on the surface of the workpiece, that is, the coordinates in the XYZ coordinate system, When each of them is stopped at a predetermined position and a spot light from the light source is irradiated on a certain irradiation point P on a line parallel to the X axis of the work surface within the overlapping field of both imaging means, both imaging means will The vicinity of the irradiation point P is imaged during the output period of the two start pulses S as shown in FIG. The signals are sequentially combined and shown in FIG. 4(b). In one processing circuit (17a), a masking circuit αQ
At the same time, the masking area M is set in the image signal, and at the same time, the slice level as shown in FIG. The following composite imaging signals are each cut and sliced, and only the peak signal higher than the level J corresponding to the irradiation point PVc is extracted to obtain a slice signal as shown in FIG. The counter 1121 determines the address where the high level pulse of the slice signal exists, that is, the address N corresponding to the light receiving element that is the output source of the extracted signal.
is counted, and the counted address N is stored in the storage unit 1141 as address data indicating the position of the irradiation point P on one imaging surface (7).

One processing circuit (x7b) processes the image signal from the imaging surface (7) of the other imaging means in the same manner as described above, and generates address data indicating the position of the irradiation point P on the other imaging surface (7) K. The address is derived as .

It is stored in the storage section (14).

Then, the image signals from both the image pickup means are transmitted to the fifth image signal.
If the signal is as shown in Figures (a) and (t)),
Both processing circuits (17a) and (17b) obtain slice signals in the same manner as described above, and address N1 . N, is counted by each counter l12I, each address N1.
4) and is stored in the arithmetic unit α to both addresses N1.
．． N.

Based on this, the coordinates of the irradiation point P are calculated and derived.

That is, considering only the XY plane of an arbitrary XYZ coordinate system whose coordinate axes are the X, Y, and Z axes shown in FIG. 1, and assuming an XY coordinate system as shown in FIG. S,, S2. The light source is LS, and both imaging hands 81
．． The magnifications of both lenses S and S are set to □ and 2, and the intersections of the X-axis and the limit lines R1 and R2 of the field of view of both imaging means S□ and S2, which are closer to the Y-axis, are 1°■ If the coordinates of 2 '6 are (a, 0) and (b, O), respectively, then the intersection points of the X-axis and the lines connecting both imaging means S, S, and the irradiation point P on the actual work surface, respectively. 1′.

■The X-axis components α and β of the coordinates of 2′ are α= a
+K,・N1・・・・・・・・・
・・－・■β−b＋、・N2−・・・・・・・・・■
It is expressed as

At this time, for example, if the center lines of both imaging means S, S2 are inclined at an angle t with respect to the Y axis, this state of imaging means S2 will be illustrated as shown in FIG. F is a condensing lens of the imaging means S2, and a point corresponding to the irradiation point P on the imaging surface [7], that is, a line T connecting the irradiation point P and the center point 0 of the lens E4, and the imaging surface (
7) is p, the center point of the imaging plane (7) is q, and the intersection between the line T and a line X' passing through point q and parallel to the X axis is p'.
Then, in the triangle pqp', it becomes pqp'-t, so the lengths d, , d2 of side pq1 and side p'q are d, q d, / cos 7'
・・・・・・・・・
...■, and the true value α' can be obtained by correcting what is derived from the above equation 0 with a correction coefficient obtained from the relationship of the above equation 0.

Furthermore, the coordinate X-axis component of the lens center point , , L, representing the installation point of both imaging means S, , S, is α
. ,β.・K is based on the Y-axis component, and D is the distance between both image sensors (6a) and (6b) in the XY plane.
Then, the coordinates of the irradiation point P on the work surface (xp, yp)
The X-axis and Y-axis components of are xp=(β.-β)(1-D+i,-β)+β...
...ΦD−K ,,,,,,
It is expressed as @yp:D+l-β, and a straight line horse passing through point V1''Ll and point ■2'・
It is given as the intersection of the straight line R4 passing through L2, and each point V1. V, , L
l, L2 coordinates (a, O), (b, 0
) ・((to, K), (β., K) By inputting the distance between , N2 and both imaging means S, , S into the calculation unit θ in advance, the magnification of both lenses is , Based on the address data N, , N2 obtained by image processing, the coordinates of points v1' and v2' are calculated according to the above 0.0 formula, and the X axis of the coordinates of the calculated points v,' , v,' Based on the components α: and β, the coordinates (xp, yp) of the irradiation point P are derived according to the above formulas Φ and is derived.

Further, the same operation as described above is repeated for each irradiation point of the spot light on the line, and the image processing means (2) 1)
The coordinates of each irradiation point in the XY plane are derived through image processing, and the three-dimensional and five-dimensional coordinates of each irradiation point are derived together with the Z-axis component determined by the position of the second guide body (3), and the irradiation point is When the point at the end of the 8-point line is reached within the overlapping field of view, the next irradiation point will be out of the overlapping field of view, so the spot light is fixed at the irradiation point at the end of the overlapping field of view. The moving body 161 f is moved by a predetermined amount in the positive direction of the X-axis, and the imaging ranges of both imaging means s,, 's, are moved within a range including the irradiation point, and both imaging means S1. A spot light is irradiated to each irradiation point on the front and back line of the work surface within the overlapping field of view of S.

Then, in the same manner as the position derivation of the irradiation point P described above, the position of each irradiation point on the JL of the surface of the workpiece (8) within the overlapping field of view after being moved by the image processing means Ca1l, that is, the coordinates in the XYZ coordinate system. is derived and moved in the positive direction of the X-axis by the moving body (6) and the second guide body (:1), and these operations are repeated to determine the position of each irradiation point on the line on the work surface. is derived, then the moving body (
6) in the opposite direction to the above by 1 sqlh'y in the negative direction of the X-axis, the imaging ranges of both imaging means S,, S, are returned to the measurement start position, and then the first motor The operation of (2) moves the second guide body (3) by a predetermined amount in the positive direction of the Z axis, and the above operation is repeated again, and the second guide body (3) is moved in the positive direction of the Z axis. The above operation is repeated each time the workpiece is moved by the predetermined amount, and the image processing means (21) determines the position of each irradiation point on the work surface, that is, the X and Y coordinate components and the amount of movement of the second guide body (3). Each three-dimensional coordinate consisting of the Z-axis component is derived,
Based on the derived three-dimensional coordinates of each irradiation point, the shape and position of the workpiece are derived and measured at the same time.

Therefore, according to the embodiment, both the imaging means S,
By moving S2 in the left-right direction and moving both imaging means S and S2 light source LS in the front-back direction, each irradiation point on the entire surface of the object to be measured can be irradiated, and moreover, each irradiation point can be illuminated in three dimensions. It is possible to reduce the measurement time by continuously calculating and measuring the position, and the shape and position of the object to be measured can be measured simultaneously with high precision, which is very practical.

Furthermore, the magnification of the lenses of both imaging means S, , S,
By selecting 2 appropriately, it is possible to accurately measure not only the shape of the workpiece but also the state of minute irregularities. Very practical.

Furthermore, since the shape of the workpiece is measured without contact, even if the workpiece is made of rubber or other flexible material that easily deforms, the shape can be easily measured.

Furthermore, since spot light is used, the energy density is low, and even weak light can be used without causing distortion to the workpiece compared to when using illumination.

Although CCD type linear image sensors are used as both imaging means, it is of course possible to use an MO8 type image sensor, an image pickup tube, or the like.

Further, in addition to rotating the light source by a motor to rotate the optical path of the spot light, the optical path of the spot light may be magnetically rotated by an electron beam or the like.

In addition, as shown in FIG. 4th guide body +2a
, 1231 are installed on the two pairs of legs -, (2)' erected at the four corners of the pedestal t241, and both ends of the second guide body (3) are placed along both guide bodies (2) and (c). It may also be moved in the front-back direction.

Further, a movable body (6) is provided on the U-shaped guide body portion so as to be movable in the left-right direction, and the guide body is attached to the left side of the mount t271.

The front and rear rails w and I2s' laid on both ends of the right side
The present invention can be implemented in the same manner even if the robot moves along the following directions.

[Brief explanation of the drawing]

The drawings show an embodiment of the three-dimensional measuring device of the present invention, FIGS. 1 to 7 show one embodiment, FIG. 1 is a perspective view of the measuring device, FIG. 2 is a block diagram of a processing circuit, Figure 3 is a block diagram of the arithmetic circuit, Figures 4 (a) to (C) are signal waveform diagrams for explaining operation, and Figures 5 (a) and (b).
are waveform diagrams of image signals from both imaging means, FIGS. 6 and 7 are operation explanatory diagrams, and FIGS. 8 and 9 are diagrams, respectively.
The figures are perspective views of other embodiments. (7)...Imaging surface, (17a), (17b)...Processing circuit, M...Arithmetic circuit, t21)...Image processing means, L...Line, P...Irradiation point. Agent Patent Attorney Fuji 1) Ryutabe WJ5 diagram

Claims (1)

[Claims] (1) A pair of imaging means that are provided movably in the left-right direction and in the front-rear direction and take images of the object to be measured, and an overlap between the two imaging means that are provided so as to be movable and rotatable in the front-rear direction together with both of the imaging means. a light source that sequentially irradiates slit light to a plurality of locations on a line in the left-right direction on the surface of the object to be measured within a field of view, a movement of both the imaging means in the left-right direction, and a movement of the imaging means and the light source in the front-rear direction; a processing circuit that processes images of each irradiation point of each of the slit lights by the two imaging means due to movement and derives the position of each of the irradiation points on the imaging surfaces of the two imaging means; A three-dimensional measurement device comprising: an arithmetic circuit that calculates and measures a three-dimensional position of each of the irradiation points on the surface of the object to be measured based on the positions on both of the imaging planes.