JPH05126541A - Instrument for three-dimensionally measuring shape of object - Google Patents

Abstract

PURPOSE:To continuously measure the shape of an object to be measured even when reflected light from the object is intercepted by a V-groove formed on the surface of the object when the Vgroove, etc., on the surface of the object is irradiated with light emitted from a light emitting section. CONSTITUTION:This instrument for three-dimensionally measuring shapes of objects is provided with an arithmetic unit which calculates the distance between a light emitting section 2 and measuring point by selecting an arbitrary light receiving section 3 receiving reflected light among the plurality of light receiving sections 3 of a distance sensor 1 provided along a circumference around the optical axis of the section 2. The arithmetic unit continuously calculates the distance between the section 2 and measuring point by selecting another light receiving section 3 receiving the reflected light when the selected arbitrary section 3 becomes impossible to receive the reflected light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to three-dimensional measurement by measuring the shape of a prototype model, for example, when manufacturing a product by NC cutting or making a mold or a die used for press working with an NC machine tool. The present invention relates to an object shape three-dimensional measuring apparatus for obtaining data.

[0002]

2. Description of the Related Art A three-dimensional measuring device of this type, as shown in FIG. 8, emits a laser beam to a measuring point P of an object to be measured W and a reflected light from the measuring point P. Light receiving section 32 including a large number of light receiving elements that receive light according to the reflection angle.
The distance sensor 30 including the
-2082, Japanese Patent Publication No. 2-16965).

In the light receiving section 32, 1024 light receiving elements 34 such as CCDs are provided in a line in a direction orthogonal to the optical axis of the light receiving lens 33, and the light receiving lens 33 emits light along the optical axis. For example, 15 with respect to the optical axis of the part 31
It is provided so that it intersects with °.

At the measuring point P of the object to be measured W, the light emitting section 3
When the light is irradiated from 1, the light is diffusely reflected at the measurement point P, and only the reflected light that has passed through the light receiving lens 33 is received by the light receiving section 32. Therefore, depending on the height of the measurement point P, the light receiving section from the measurement point P is received. The reflection angle of the light reflected toward 32 changes, and the light receiving position on the light receiving unit 32 also changes.

That is, since the light receiving position at the light receiving unit 32 changes according to the distance between the measuring point P and the light emitting unit 31, the distance to the measuring point P can be obtained according to the light receiving position. Then, the coordinate value of the measurement point P can be easily obtained based on the coordinate value of the light emitting unit 31 and the obtained distance.

[0006]

However, when a steep slope 35 such as a V groove or a step is formed on the surface of the object to be measured W, even if the light is emitted from the light emitting section 31 to the slope 35, the reflected light is not reflected. The object to be measured W is blocked by the slope and does not reach the light receiving unit 32.
Since it is not possible to obtain the distance to, it is not possible to obtain the three-dimensional data of that portion. Therefore, the present invention is
Even if a steep slope or the like is formed on the surface of the object to be measured W, it is a technical problem to be able to accurately measure the three-dimensional data of the object to be measured.

[0007]

In order to solve this problem, the present invention relates to a light emitting section for irradiating a measuring point of an object to be measured with light and a reflected light from the measuring point according to its reflection angle. Three-dimensional measuring device of object shape for obtaining the distance between the light emitting portion and the measuring point by a distance sensor having a light receiving portion composed of a large number of light receiving elements for receiving light and calculating coordinate values of the measuring point based on the distance. In the above, the light receiving section of the distance sensor is provided in a plurality of sets along a circumference centered on the optical axis of the light emitting section, and any light receiving section receiving reflected light is selected to select a light emitting section and a measurement point. When the reflected light is no longer received by the light receiving part, another light receiving part receiving the reflected light is selected and the distance between the light emitting part and the measurement point is continuously calculated. It is characterized by having a computing device.

[0008]

According to the present invention, when light is emitted from the light emitting portion to the object to be measured, the light is diffusely reflected on the surface of the light emitting portion, and a plurality of light emitting portions are arranged along the circumference centered on the optical axis of the light emitting portion. The light is received by each of the light receiving units. Therefore, the distance between the light emitting unit and the object to be measured can be accurately obtained by any light receiving unit that receives the reflected light.

Further, even if the light reflected from the measuring point toward the light receiving portion being measured is blocked by the unevenness or steps formed on the surface of the object to be measured, other light receiving light is received. Since the distance between the light emitting unit and the object to be measured can be measured by switching to the unit, the coordinate value of the measurement point can be calculated reliably and quickly without making measurement impossible.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on the embodiments shown in the drawings. FIG. 1 is a perspective view showing an example of the device of the present invention, FIGS. 2 and 3 are schematic configuration diagrams showing a distance sensor, and FIG.
Is a block diagram of the device of the present invention, and FIGS. 5 to 7 are explanatory views showing a usage state.

In the figure, reference numeral 1 is a distance sensor for measuring the distance to the measuring point of the object to be measured W, which is an X-direction moving table Tx and a Y-direction moving table for supporting the object to be measured W in the XY directions. The table Ty and the Z-direction moving table Tz that moves the distance sensor 1 in the Z direction are arranged so as to be relatively movable in the XYZ directions with respect to the measured object W.

The distance sensor 1 includes, for example, He-Ne.
A light emitting part 2 for outputting a laser beam is arranged in the central part, and two light receiving parts 3, 3 are arranged in the diametrical direction along a circumference centered on the optical axis. Each light receiving unit 3
Is provided with a light receiving element 5 formed by, for example, 1024 CCDs arranged in a line in a direction orthogonal to the optical axis of the light receiving lens 4, and the optical axis of the light receiving lens 4 is at a predetermined angle (eg, with the optical axis of the light emitting unit 2). It is attached integrally so as to intersect at 15 °).

The distance sensor 1 is tiltably supported by a lower end portion of a rotation axis Az parallel to the Z axis, and has a rotation axis Az.
The optical axis of the light emitting unit 2 can be tilted at an arbitrary angle by an Az axis drive motor 6 that rotates the lens and a tilt motor 7 that tilts the distance sensor 1. Further, the light emitting unit 2 and the light receiving unit 3 are attached to a piston rod of a cylinder 8 that can advance and retreat in the optical axis direction of the light emitting unit 2 and can be rotated about the optical axis of the light emitting unit 2 by, for example, an ultrasonic motor 9. It is supported.

Reference numeral 10 denotes a support for supporting the object to be measured W, and in the case of this example, a rotation axis Ax for rotatably supporting the central axis of the object to be measured W and A for rotating the axis Ax by a predetermined angle.
It is composed of an x-axis drive motor 11. The rotation axis Ax is arranged in parallel with the X axis, and the cut surface passing through the central axis of the object to be measured W is used as a reference plane so that the reference plane can be attached in a state parallel to the XY plane. Has been done. In addition,
When it is not necessary to measure only the front surface side and the back surface side of the object to be measured W, the object to be measured W may be directly attached to the X-direction moving table Tx without being attached to the rotation axis Ax.

Reference numeral 12 is a focusing device for focusing the focal point F on the measuring point, and is provided in the distance sensor 1.
As the measurement accuracy of the light receiving unit 3 is increased, the measurement depth becomes shallower (for example, about 10 mm). Therefore, if unevenness or a step deeper than the measurement depth is formed on the object to be measured W, the position of the measurement point becomes the measurement depth. It deviates from and becomes impossible to measure.

Therefore, as shown in FIG. 3, the measurement depth is selected deeper than that of the light receiving section 3, and the focus position thereof is set to the light receiving section 5.
The focus device 12 set within the measurement depth of
When the position of the measurement point exceeds the measurement depth of the light receiving element 5 due to the unevenness or steps of the object to be measured W, the distance to the measurement point and the moving direction are output as a detection signal.

Therefore, according to the detection signal, the focus F
According to the position of the measurement point, the Z-direction moving table Tz is moved by a predetermined amount when the optical axis is parallel to the Z axis, and when the optics is tilted, the moving tables Tx, Ty and Tz are simultaneously moved. The optical sensor 1 is moved in the optical axis direction by moving it by a fixed amount. The cylinder 8 may be expanded and contracted by a predetermined length, and in this case, the optical sensor 1 can be moved in the optical axis direction regardless of the inclination of the optical axis.

Although the focus device 12 cannot measure the distance as accurately as the light receiving section 3, it has such an accuracy that it can focus within the measurement depth of the light receiving section 3, so that the focus F is By measuring the distance by the light receiving unit 3 at the time when the measurement point is met, it is possible to perform quick and highly accurate measurement.

Reference numeral 13 denotes each moving table Tx, Ty and T according to a preset program and the shape of the object to be measured W.
z, Az axis drive motor 6, tilt motor 7, cylinder 8,
When a control signal for driving the ultrasonic motor 9 and the Ax-axis drive motor 11 is output, and one of the light receiving units 3 that receives reflected light is selected and no reflected light is received by the light receiving unit 3. The control device outputs a control signal for selecting the other light-receiving unit 3 that receives the reflected light.

Numeral 14 is an arithmetic unit for calculating the XYZ coordinate values of the measuring points, which are the moving tables Tx, Ty.
And a moving amount of Tz, a rotation angle of the Az axis, a tilt angle of the tilt motor 7, and a calculation unit 15 that calculates the coordinate value of the light emitting unit 2 based on the expansion and contraction amount of the cylinder 8, and the rotation angle of the Az axis and the tilt motor 7. An arithmetic means 16 for calculating the inclination of the optical axis of the light emitting portion 2 with respect to the coordinate axis based on the inclination angle of, and an arithmetic means 17 for obtaining the distance between the light emitting portion 2 and the measurement point based on the output signal from the distance sensor 1. The calculation means 18 calculates the XYZ coordinate values of the measurement points based on the calculation results of the calculation means 15, 16 and 17.

The above is an example of the configuration of the present invention, and its operation will be described below. For example, a case of raising a metal mold for molding a doll's head will be described. A head model is attached to the Ax axis as the object to be measured W, and the optical axis of the light emitting unit 2 is irradiated onto the surface of the object to be measured W. Then, the coordinates of each measurement point are measured in a line while moving the X-direction movement table Tx from the throat toward the crown at a predetermined pitch. At this time, if the optical axis of the light emitting unit 2 is directed vertically downward so as to be in the direction of the Z axis and intersects with the Ax axis, the coordinate value of the measurement point can be more easily calculated.

Next, the object W to be measured is rotated by a predetermined angle (for example, 1 °) by the Ax-axis drive motor 11, and the X-direction moving table Tx is moved at a predetermined pitch from the top of the head to the throat. Calculate the coordinate values. At this time, since the object to be measured W is rotated, its coordinate value is calculated by being corrected by the calculation means 18 according to the rotation angle of the rotation axis Ax. Then, by repeating this, the coordinate values can be calculated for the measurement points on the entire circumference of the object W to be measured.

Further, as shown in FIG. 5 (a), when the positions of the light receiving portions 3 and 3 are set parallel to the X-axis, for example, and the light receiving portion 3 behind the traveling direction (left side in the drawing) is used for measurement. To
When the V groove 20 having an angle smaller than the reflection angle of the reflected light is formed on the surface of the object to be measured W in the direction orthogonal to the X-axis direction, the reflected light from the slope of the V groove 20 is blocked by the slope. Therefore, the light does not reach the light receiving unit 3. At this time, the control device 13
A control signal from the switch switches to the light receiving unit 3 (on the right side in the drawing) in the forward direction.

Further, as shown in FIG. 5B, the reflected light from the vicinity of the bottom of the V groove 20 is blocked by the slopes on both sides and is not input to any of the light receiving portions 3 and 3, so that at this time. As shown in FIG. 5C, the distance sensor 1 is rotated by the control signal from the control device 13 about the optical axis of the light emitting unit 2 to a position where the light receiving unit 3 receives light.
The measurement is performed by one of the light receiving units 3 that receives the reflected light.

In this case, when the optical axis of the light emitting section 2 is parallel to the Z axis, the distance sensor 1 may be rotated by driving the Az axis drive motor 6 or the ultrasonic motor 9, and the optical axis is tilted. If so, the distance sensor 1 may be rotated by driving the ultrasonic motor 9.

Further, as shown in FIG. 3, when the measurement point deviates from the measurement depth of the light receiving portion 3 due to a step or unevenness formed on the surface of the object to be measured W and having a depth larger than the measurement depth, the focus device 12 is operated. The distance sensor 1 is moved in the optical axis direction based on the detection signal. Since the distance to the measurement point and the moving direction are output from the focus device 12 as a detection signal, the distance sensor 1 is moved in the predetermined direction along the optical axis of the light emitting unit 2 by the predetermined distance, and the measurement point and the focus point are moved. F is matched,
It is possible to measure three-dimensional data without loss of measurement time.

At this time, when the optical axis is parallel to the X axis, Y axis or Z axis, the corresponding moving tables Tx, Ty, Tz are moved in a predetermined direction by a predetermined amount, and the optical axis is tilted. If so, the optical sensors 1 can be moved in the optical axis direction by simultaneously moving the moving tables Tx, Ty, Tz by a predetermined amount. Of course cylinder 8
May be expanded or contracted by a predetermined length.

Further, for example, as shown in FIG. 6, when a steep slope 21 is formed on the object to be measured W and a recess 22 is formed in the middle of the slope, the optical axis is parallel to the Z axis. When the measurement is performed under the condition, the measurement points P _{1 to} P
_Since only the three-dimensional data of ₈ can be measured, it is not possible to grasp the accurate object shape, and even if the measurement pitch is made fine, it is not possible to measure the inside of the recess 22.

Therefore, in such a case, the recess 22 is obtained by driving the Az axis drive motor 6 and the tilt motor 7 and measuring the optical axis of the light emitting section 2 in a state in which the optical axis is tilted in a direction substantially orthogonal to the slope. The XYZ coordinate values inside the can also be measured.

Further, for example, a semi-cylindrical cylinder as shown in FIG.
For the object to be measured W connected at 0 °, the light emitting unit 2
The object shape can be accurately measured by inclining the optical axis of the object in a direction substantially orthogonal to the measurement surface of the object to be measured W according to the measurement site. For example, in the portion extending in parallel with the X axis, the Az axis drive motor 6 is rotated by a predetermined angle so that the optical sensor 1 is tilted in parallel with the YZ plane, and an arc is formed in the YZ plane. Moving table T as you draw
y and Tz are moved by a predetermined amount, and the tilt motor 7 is rotated by a predetermined angle.

Regarding the portion extending in parallel with the Y axis, the Az axis drive motor 6 is rotated by a predetermined angle so that the optical sensor 1 is tilted in parallel with the XZ plane, and an arc is formed in the XZ plane. The moving tables Tx and Tz are moved by a predetermined amount so that the tilt motor 7 is rotated by a predetermined angle.

Further, regarding the connecting portion, the optical sensor 1 is Y-
The Az-axis drive motor 6 is rotated by a predetermined angle so as to be tilted parallel to the plane of 45 ° with respect to the Z-plane and the X-Z plane, and the moving table Tx, so as to draw an arc in the plane.
Ty and Tz are moved by a predetermined amount, and the tilt motor 7 is rotated by a predetermined angle.

In the description of the embodiment, the light receiving section 3
Although only two cases have been described, the number is arbitrary. However, as the number of light-receiving units 3 increases, particularly if light-receiving units are provided without gaps along the circumference centered on the optical axis of the light-emitting unit 2, the light diffusely reflected from the measurement point is received in all directions. Can reduce blind spots. Also, the optical sensor 1
In the case of rotating around the optical axis of the light emitting section 2, one light receiving section 3 is sufficient, but if the number is large, it is possible to cover all directions with a small rotation angle. Further, as means for moving the distance sensor 1 relative to the object to be measured W in the X-axis direction, the Y-axis direction, and the Z-axis direction, even if the distance sensor 1 is moved, the object to be measured W is It may be moved.

[0034]

As described above, according to the present invention, a plurality of light receiving portions are formed along the circumference centering on the light emitting portion of the distance sensor, and any light receiving portion used for distance measurement is formed. Even if the reflected light is not received at, the distance can be measured at the other light receiving part where the reflected light is received, so the coordinate values of the measurement points can be calculated continuously and accurately without interrupting the measurement. It has an excellent effect of being able to.

[Brief description of drawings]

FIG. 1 is a perspective view showing a device of the present invention.

FIG. 2 is a schematic configuration diagram showing a distance sensor.

FIG. 3 is a schematic configuration diagram showing a distance sensor.

FIG. 4 is a block diagram showing the device of the present invention.

FIG. 5 is an explanatory diagram showing a usage state.

FIG. 6 is an explanatory diagram showing a usage state.

FIG. 7 is an explanatory view showing a usage state.

FIG. 8 is a schematic configuration diagram showing a conventional measuring device.

[Explanation of symbols]

1 ... Distance sensor 2 ... Light emitting part 3 ... Light receiving part 6 ... Az axis drive motor 7 ... Tilt device 8 ... Cylinder 9 ... Ultrasonic motor 10 ... Measured Object support 11 ... Ax axis drive motor 12 ... Focus device 13 ... Control device 14 ... Arithmetic device

Claims (4)

[Claims] 1. A light receiving section comprising a light emitting section (2) for irradiating light to a measuring point of an object to be measured (W) and a plurality of light receiving elements for receiving reflected light from the measuring point according to its reflection angle. In a three-dimensional measuring device for an object shape, the distance sensor (1) including a part (3) determines a distance between a light emitting part (2) and a measurement point, and calculates coordinate values of the measurement point based on the distance. An arbitrary light receiving part (3) is provided in which a plurality of light receiving parts (3) of the distance sensor (1) are provided along the circumference centered on the optical axis of the light emitting part (2) and the reflected light is received. ) Is selected to calculate the distance between the light emitting unit (2) and the measurement point, and
When the reflected light is no longer received by the light receiving unit (3), another light receiving unit (3) receiving the reflected light is selected to continuously maintain the distance between the light emitting unit (2) and the measurement point. A three-dimensional measuring apparatus for object shape, comprising a calculation device (17) for calculating. 2. A light receiving section comprising a light emitting section (2) for irradiating light to a measuring point of the object to be measured (W) and a plurality of light receiving elements for receiving reflected light from the measuring point according to the reflection angle thereof. In a three-dimensional measuring device for an object shape, the distance sensor (1) including a part (3) determines a distance between a light emitting part (2) and a measurement point, and calculates coordinate values of the measurement point based on the distance. When the distance sensor (1) is attached to a rotating device (6, 9) whose rotation axis is the optical axis of the light emitting section (2), and the reflected light is no longer received by the light receiving section (3), the rotation is performed. The reflected light is received by the light receiving unit (3) and the control device (13) that drives the device (6, 9) to rotate the distance sensor (1) to a position where the light receiving unit (3) can receive the reflected light. An arithmetic unit (1 that sometimes calculates the distance between the light emitting unit (2) and the measurement point
7) A three-dimensional measuring device for measuring the shape of an object, comprising: 3. A light receiving section (2) for irradiating light to a measuring point of the object to be measured (W), and a plurality of light receiving elements for receiving reflected light from the measuring point according to its reflection angle. In a three-dimensional measuring device for an object shape, the distance sensor (1) including a part (3) determines a distance between a light emitting part (2) and a measurement point, and calculates coordinate values of the measurement point based on the distance. A rotation device (11) for rotatably supporting the object to be measured (W) by a rotation axis (Ax) parallel to any one of the three-dimensional coordinate axes, and the rotation device (11) is driven to rotate the rotation device (11). A control device (13) for rotating the shaft (Ax) by a predetermined angle, and an arithmetic device (14) for correcting and calculating the coordinate value of the measurement point according to the rotation angle of the rotation shaft (Ax) are provided. Three-dimensional measuring device for characteristic object shape. 4. A light receiving section comprising a light emitting section (2) for irradiating light to a measuring point of the object to be measured (W) and a large number of light receiving elements for receiving reflected light from the measuring point according to its reflection angle. In a three-dimensional measuring device for an object shape, the distance sensor (1) including a part (3) determines a distance between a light emitting part (2) and a measurement point, and calculates coordinate values of the measurement point based on the distance. A focus device (12) having a deeper measurement depth than that of the light receiving section (3) and having a focus within the measurement depth of the light receiving section (3) is integrally attached to the distance sensor (1). When the measurement point deviates from the measurement depth of the light receiving section (3), the distance sensor (1) is moved in the optical axis direction of the light emitting section (2) so as to focus the measurement point on the focus of the focusing device (12). Object comprising a control device (13) for relatively moving along Three-dimensional shape measuring device.