JPS5943308A - Method and apparatus for detecting three-dimensional shape - Google Patents

Abstract

PURPOSE:To enable to determine the coordinate values of a contact point with high accuracy by a method wherein a rotary vibrator is attached to a feeler shaft supporting a spherical measuring probe to apply a rotating vibration of minute angle to the probe. CONSTITUTION:A rotary vibrator 3 is attached to a feeler shaft 2 supporting a spherical measuring probe 1 to apply a rotating vibration omega of minute angle to the probe about the Z-axis passing the center thereof. An output from a dynamometer issued when the measuring probe 1 comes into contact with the material to be measured is integrated over a time longer than the period of the rotating vibration. By so doing, an error due to friction resistance can be ignored, and it becomes possible to determine the coordinate values of the contact point with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the Jj method and apparatus for measuring the shape and size of an object whose surface is fully curved, such as a bow, by bringing a spherical measuring tip into contact with the surface of the object. To measure the shape and dimensions of
) T': A spherical measuring element is provided on the IU, and it is brought into contact with the surface to be measured, and the I116 target value at JC is determined from the shape metalwork coordinate values.

First, conventional measurement using a spherical probe will be explained. Auto' tree 1 figure Hikoo... and the perpendicular direction tIll + F end (16 spherical 1lli constants are removed 1, j, X)'
Fix Φ11J and lower ZIllllI by r'', I
Assume that the probe contacts the surface to be measured at point l'O. In other words, if the measurement point is 1f perpendicular to the Z axis or the apex of a convex surface, then the coordinates of the PO point are the center coordinates of the sphere 0 (Xo, ~0°ZO), then the radius of one sphere is 1゜'
, J>++ ego value for HZo.

That is, (XO, '10, ZO4-TO).

Generally, the IF 0 point is determined by this method.

However, as shown in Figure 2, the surface to be measured is Z II! Il
On the other hand, if the volcanic stone (-) is dropped directly, as in Figure 1, it will come into contact at the Qo point, but not at the PO point on the vertical line.However, 4
With 0-1 leopard, let P(-1 point) be the target value of -16 and 2).

・　　　1 , ε To(, -ζ7-1).

Here, β is the angle that the surface to be measured makes with the X·)′ plane. However, conventionally this contact point (20's i+'j: +
Alternatively, there is no way to accurately detect the nodding angle β of the i-regular surface. Therefore, to reduce this error ε, a method is used to reduce the cliff diameter of the sphere2, but this not only lowers the mechanical strength but also causes pressure damage on the surface to be measured. In practice, there was a limit to how small the radius of the sphere could be.

Therefore, using a spherical measuring tip that does not cause any practical problems,
It is an object of the present invention to detect whether the ball is in contact with the surface to be measured υ or υ at the position of the ball, perform correction, and obtain a measurement result of j)-L.

As shown in Figure 3, place the probe on the surface to be measured with the measurement pressure
), the vector direction of the force (P) coincides with the normal vector of the surface to be measured.
Iゝ) is accurately detected. 71<-J-(iν1 structure) for the child's group ξ, make a probe'\nod,'ζ.This 52-piece mouth-)' head is made into a mold for taking A'. Yo・Tute use ζ mark (1 river 'y'rl + Iku no Z tllll
lt 'l-' y, i, i Uko1lVi=+KerereZ]. Spherical 4) 11 fixed 1 is enough rigidity to be able to hold 2U of noisy material. And 7 ten no 1 no axis 20111 day 51 spherical measurement, I'&' this one state gill it
(Rule 5j Stomach 14 Power 11 for detecting reaction force P
4VC taken 1.1 digits. Power here, 114baX・)
The component of the force in the two directions of ゛・Z is also qi 1. ) A device that is detected separately as a bow, commonly available in commercially available tongues.

Then, if the -force surface component of Jj1 is not processed by 1i13', then the normal vector of the fixed surface is 7 (I and the contact point of 9 balls is found. It will be done.

However, when I took measurements in January, I found the following problem.

As shown in Figure 2, fix the X-Y bow.

Z ll1llll 'i: Speed~'()mo-biC1・
Let it fall, X. This top, 21', shown in Figure 5-J', sea urchin,
Frictional force at the contact point 1゛ei/-, i=zu;6 +9. :
The direction of the j force is 4111 agency f-, and here I
) h 1llllll constant pressure, 7+ is friction coefficient. This j
? Due to the frictional force J, the output of the dynamometer is L (moxibustion).
Each +lii direction component of the quantitative pressure reaction force P has this frictional force 1.
Each axis direction component of ゛ is added, and there is only that much error.

In other words, in Fig. 5, t, there is a tangent at the QO point, 11 + tl.
: Despite the fact that there is a friction force of 1.
−1・゛), and the contact point (bow, direction of this vector I
%! Jinping 1J (moved 7 times, the center of taste intersects with the spherical surface (my wife/:,) and I'll be disappointed. So this error ↓; Zeng (212) shi) It is necessary to make 1 shaku of Nagisa L (
It turns out that there is. In addition, this 11. Since the old force F varies depending on the surface condition of the surface to be measured and the speed of contact 11.5, it can be easily expressed as follows. reactor·?
J I can't do that.

In order to improve the present invention (-, j, u [・
child.

Spherical 11111 constant J'-1 supported 1)
・At 1112, move the rotational vibration exciter 3 to the center 4: Trace the rotational vibration ω at the center of the axis.

Now, X・)′′ is fully fixed + Z′l′+ll is the speed V
(Fig. 3 (・(: Showing the garden 1st cow, target (・Ko 1 slanted guko cover 11ijl fixed position A BCp・ko contact) QJ: Consider the relationship when゛J“ru.

Figure 7 shows the state of the force generated at the contact point l0 at this time, and 1 in Figure 1 is Figure 0. It is a plan view of Al-30 of spherical measuring point 1' (-1) and the relative velocity V d with the direction to be measured (Al[') at -1.
A1. , '3 C-''(l[ril- provided on 1(-S
e (If you think about it in terms of votes.

■-[\envy sin β, ωYos group β'C05 (t) 11
What is the content of the frictional force components of Fs and Fe?

matter(・yo\/(1-,,,>small (lower contact measurement)
, CD-Inu Yo) Thick (rotating Yu-+41 to make it faster) Where, from this condition vrc, the 1・゛s component of the frictional force (
f is a negligible value. On the other hand, due to the 1.0 configuration,
l”e-knee 1p-p square n 戊(around $IJl 2π
-ω[), so one person ゛)・-? Integrate the signal for the evening time and find the average value of 2 hours]/-.

Assuming that the peaks are all Fs and I'8.

1G=Me=’-J”Ps・di Knee ()t.

剋二郎”-J”11・e・(lt-: 0 とな-).

t.

It is theoretically clear that errors due to frictional resistance can be ignored.

As a result, the signal values (Rx, I'Ly, I(z
) is 19Rx-I) sinβ-5in7- Ry = p sinβ-cos 7'1 is also 7. ::
I) CO8β Rx2+R, y2-L Rx2-1)2 (r is the angle J of the angle OBC in Figure 6), calculate the angles of β and 7', and determine the normal vector N from this Jt. 1 Tangent of spherical probe 1'l! l! I
'4- The target position can be determined. Therefore, with high precision, the j of the contact point can be
No. 1 is the target for all decisions L]" Notona 2].

Figure 1
,,,lOtori L2) If all conditions are specified, the radius of taste is i! - is several mm or more I-, and its -1・descending speed'' (Rep. 1) Ii' A frequency 2 where the circumferential velocity is nJ [For example, when moving the pig at a minute angle from 10011z to 3,00011z] It vibrates. Then, the contact 11, -Ni ( ) et al J"L /This power -11 output (11 - rotation vibration period I11" of the bow) IK is more than 11, Explosion jj] - C Integrating V , -), the frictional resistance t is greater than tj! :4
;'r removed [7, high precision measurement is possible.

In addition, the method of removing the vibration component due to rotational vibration (, Toshide, and the method of taking the average 'H1iI'j'i?' with the precision [7) (one situation is clear for two /, -, but in an electric circuit, it is equal to the JJft component) A similar result can be obtained with the equivalent effect of the lower range [1] for Luther's [7].

[Brief explanation of drawings]

FIG. 1 Q'' is an explanatory diagram of an ideal contact state of a spherical probe. Figure 2 U shows a measurement error when the direction to be measured is F cinders.
Figure 4 is a side view showing the configuration of the throat of the glove for measuring cubic round shapes of the present invention, Figure 5 is an explanation of errors caused by frictional resistance. Figure, 6th
The figure is an explanatory diagram showing the relationship between the tilted direction to be measured and the force of the measuring element according to the present invention.
Figures 1, 8, and 9 are 1.5. A waveform diagram of I/θ. 14 Spherical measuring head 2 Neurer limb 3 Rotating exciter 4 Dynamometer Patent applicant Co., Ltd. Tokyo Seisuiwa Unrun No. 1 [Z / Xr, s t〆] 1.5 ＼ bar
-Oth (I shukul・1

Claims (1)

[Claims] (1) A probe head of a coordinate measuring machine, etc. that detects the dimension and shape of a surface to be measured by bringing a probe into contact with the surface to be measured (
, and ↓...Then, each axial component lLx, Ry, 11.z of (1 (11 constant II multiplication vector 1)) which the spherical measurement -J'- receives from the surface to be measured is measured by the dynamometer υ. Electricity 10 and (7) are taken out, (- output No. 18 is connected to d11
Find the surface normal vector t of the constant j, and from this vector value, detect the contact position 1r1- on the 1st ice-like probe-42)
and -11, to. Keeping the spherical measurement J゛-, the small angle rotational vibration I'lIJket) can be obtained at a constant circumference on the neu-5-axis of l''1I-J'.
(From -, at the time of contact C' Force method. (:2) N1 - range of search 11-1" 1 description 6' (2)..., the rotation force added by Eve j, the dynamic component as 1 force, the power 2 ", 1・v out)"J 'I't
T-bow 5: A two-dimensional shape detection method that integrates over a period longer than the length of a sphere. (3) In the statement of claim 1, 41 force tl
1. - A three-dimensional detection power method in which the output signal of the dynamometer is passed through a low-pass filter with a cut-off frequency lower than the fundamental frequency of the rotational vibration frequency of the spherical probe as a means for removing the rotational vibration component. (4) Coordinate measuring machine scrap I' that uses a spherical measuring tip:
i - In Buhenot, solidify the sphere on the tip ☆, tj, H 5
F', X, Y, which receives the /C filler shaft at the time of contact
7.0 stress is coupled to a two-way component electric signal and a dynamometer outputting at 17, and two 1 seal l1ll11 (・(
A detecting device for a three-dimensional shape of an ox, which is characterized by the following: (a) a rotary exciter (a) which performs two constant period minute angular rotational vibrations;