JPH02201211A - Three-dimensional coordinates input apparatus - Google Patents

Abstract

PURPOSE:To obtain three-dimensional coordinates of an object to be measured by arranging a position indicator for indicating two points in two-dimensions, a two-dimensional position detector, a vertical position detector and a signal processor and tracing a circumferential surface of an object to be measured. CONSTITUTION:For example, a probe 17 of a vertical position detector 14 is made to abut a circumferential surface of an object 4 to be measured vertically to copy it and positions of position indicators 12p and 12q at this time are outputted as two-dimensional position signal with a two-dimensional position detector 11. The current vertical position is detected with a vertical position detector 14 to output a vertical position signal. When all measurements are performed in the vertical way of the object 4 to be measured, a vertical measuring point is shifted by a specified position to perform a measurement again and all circumferential surfaces of the object 4 to be measured or a specified measuring area to complete the measurement. A processing of a signal obtained as a result of the measurement is performed with a processor 20.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a three-dimensional coordinate input device that can obtain three-dimensional coordinates of an object to be measured by tracing the surface of the object.

[Conventional technology]

FIG. 9 shows an outline of an example of a conventional three-dimensional coordinate input device.

This three-dimensional coordinate input device has a conversion element 2 at the tip of a pen-shaped position indicator 1 that converts an ultrasonic signal into an ultrasonic wave.
is provided, and an ultrasonic signal is guided from an ultrasonic generator 3 to the conversion element 2 of this position indicator 1.

The object to be measured 4 is traced with the tip of the position indicator 1, and the ultrasonic waves from the traced point are received by the sensors 5X, 5Y, and 5Z provided at each point on the X, Y, and Z axes. sensor 5
Signals from X, 5Y, and 5Z are input to the processing device 6, and the processing device 6 determines the coordinates of the point indicated by the tip of the position indicator 1. In other words, in this three-dimensional coordinate input device, ultrasonic waves are transmitted from the tip of the position indicator 1 to the sensors 5X, 5
The distance from the tip of the position indicator 1 to each reception point (sensors 5X, 5Y, 5Z) is calculated based on the time until reception at Y and 5Z, and based on this, the distance indicated by the tip of the position indicator 1 is calculated. It determines the coordinates of a point.

[Problem to be solved by the invention]

However, since the propagation speed of ultrasonic waves differs depending on the temperature, the above three-dimensional coordinate input device that uses ultrasonic waves for measurement needs to be corrected depending on the temperature, and this correction is extremely difficult. , a problem arises in terms of accuracy.

Further, in the three-dimensional coordinate input device, when the object to be measured 4 is cylindrical as shown in FIG. 10, when the tip of the position indicator 1 is inserted into the cylindrical shape, ultrasonic waves It has the disadvantage that it cannot reach the receiving points (sensors 5X, 5Y, 5Z) and cannot perform measurements.

Further, in the three-dimensional coordinate input device, the position instruction 111 indicates the position of the object to be measured 4 between each reception point (sensors 5X, 5Y, 5Z), that is, the position of the object to be measured 4 for each reception point. Even when located on the back side, ultrasonic waves are transmitted to each reception point (sensor 5
It has the disadvantage of not being able to reach X, 5Y, 5Z).

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a three-dimensional coordinate input device that has no restrictions on the measurement point when measuring the three-dimensional coordinates of an object to be measured, and is capable of measuring regardless of external environmental conditions such as temperature. The purpose is

[Means to solve the problem]

In order to achieve the above object, a three-dimensional coordinate input device according to the present invention includes a position indicator that indicates at least two points on a two-dimensional plane, and a two-dimensional coordinate input device that detects a position indicated by the position indicator. a two-dimensional position detection device that outputs a position signal; and a vertical position that is provided in the two-position indicator and detects a position perpendicular to the two-dimensional measurement surface of the two-dimensional position detection device and outputs a vertical position signal. It is characterized by comprising a detection device and a processing device that processes, stores and displays each signal from the two-dimensional position detection device and the vertical position detection device, The device is characterized by comprising a support provided on the device, a slider that slides along the support, a probe provided on the slider, and a conversion device that converts the amount of movement of the slider into an electrical signal.

[Effect]

For example, the probe of the vertical position detection device is brought into contact with and traced in the vertical direction of the surface of the object to be measured.

The position of the position indicator at this time is output as a two-dimensional position signal by the two-dimensional position detection device. Further, the vertical position at this time is detected by a vertical position detection device and a vertical position signal is output. In this way, when all measurements have been completed in the vertical direction of the object to be measured, the measurement point in the vertical direction is shifted by a predetermined position and the above measurement is performed again. Once the measurement area has been measured, the measurement ends. At this time, the signal obtained as a result of the measurement is processed by the processing device.

Although the above measurements were performed in the vertical direction, there is also a method of measuring in the horizontal direction. In this method, the above-mentioned measurement is performed in so-called round slices. Even in this manner, the three-dimensional coordinates of the object to be measured can be obtained.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A three-dimensional coordinate input device according to the present invention will be specifically described below based on an embodiment shown in one figure.

FIG. 1 is a perspective view showing an embodiment of a three-dimensional coordinate input device according to the present invention.

The three-dimensional coordinate input device 10 shown in FIG. 1 has a configuration in which a base 13 provided with position indicators 12p and 12q that can indicate at least two points on two dimensions can be freely moved on a two-dimensional position detection device 11. It has a structure in which a vertical position detection device 14 is provided on a base 13.

The two-dimensional position detection device 11 is a position indicator 12p.

This is a device that detects the position indicated by 12q and outputs it as a two-dimensional position signal, and its structure is described in, for example, Japanese Patent Laid-Open No. 63-295902. The two-dimensional position detecting device 11 is schematically shown in FIG. 2, and the principle of the two-dimensional position detecting device 11 will be explained in accordance with the figure.

This two-dimensional position detection device 11 is a position indicator that generates a steady magnetic field by winding a first coil 22 around the end of a magnetostrictive transmission medium 21 made of a ferromagnetic material such as an amorphous alloy containing a large amount of iron. The main component is a second coil 24 wound around the range where the position indicated by 12p and 12q is to be detected.

The first coils 22 generate instantaneous magnetic field fluctuations perpendicular to the coil surface to generate magnetostrictive vibration waves at each winding portion of the magnetostrictive transmission medium 21. Each first coil 22 is connected to the first multiplexer 25. is connected to a pulsed current generator 26 that can supply the first coil 22 with a pulsed current sufficient to generate magnetostrictive vibration waves. This first coil 22 is connected to a pair of adjacent magnetostrictive transmission media 21.
are wound as a set, and a pulse current is applied to each pair of magnetostrictive transmission media 21 selected by the first multiplexer 25. Here, each set of the combined magnetostrictive transmission media 21 is given a subscript "at be at d", and one of the same sets is given a subscript "2", and the other one is given a subscript "2".
with 21a, , 21a, , --, 21da
, , 21d, and the same applies to the members related to the magnetostrictive transmission medium 21 hereinafter.

A bias magnetic generator 28 made of, for example, a permanent magnet is disposed facing the end face of the magnetostrictive transmission medium 21 on the side around which the first coil 22 is wound. A bias magnetic field parallel to the longitudinal direction of the magnetostrictive transmission medium 21 is formed at the rotated portion.

Like the first coil 22, the second coil 24 is also wound with adjacent magnetostrictive transmission media 21 as a set, and the same pair of magnetostrictive transmission media 21 around which the first coil 22 is wound are wound as a set. It's Toshide. This second coil 24 is for detecting the induced voltage generated by the magnetostrictive oscillation wave propagating through the magnetostrictive transmission medium 21, and the winding direction of each second coil 24 is the same, and the - set of magnetostrictive transmission medium 2
1 reverses the polarity.

This second coil 24 is connected to a second multiplexer 27.
It is connected to the processing device 20 via.

The processing device 20 sends a signal to both the first multiplexer 25 and the second multiplexer 27 to connect the first coil 22 wound around the magnetostrictive transmission medium 21 of the set and the pulse current generator 26, and A second coil 24 wound around the set of magnetostrictive transmission media 21 is connected to this processing device 20 .

Then, when a pulse current is applied to the first coil 22, the first
An instantaneous magnetic field fluctuation occurs in the coil 22, and the magnetostrictive transmission medium 2
Magnetostrictive vibration waves are generated at the portion around which the first coil 22 of No. 1 is wound. This magnetostrictive vibration wave propagates in the longitudinal direction of the magnetostrictive transmission medium 21 at a propagation speed specific to the magnetostrictive transmission medium 21. During this propagation, the electromechanical coupling coefficient (a coefficient indicating the conversion efficiency from mechanical energy to electrical energy (or from electrical energy to mechanical energy)) at each part of the magnetostrictive transmission medium 21 where the magnetostrictive vibration wave exists. Conversion from mechanical energy to magnetic energy is performed depending on the magnitude of , and an induced voltage is generated in the second coil 24 .

At this time, if a steady magnetic field exists in any part of the magnetostrictive transmission medium 21 to the extent that its electromechanical coupling coefficient becomes large, when the magnetostrictive vibration wave reaches that part, the second
A large induced voltage V is generated in the coil 24.

The time T from the time when the pulse current is applied to the first coil 22 until the induced voltage V is detected is determined by the position indicator 12 from the position where the magnetostrictive vibration wave is wound around the first coil 22 of the magnetostrictive transmission medium 21. Therefore, if this time T is measured by the processing device 20 and multiplied by the propagation speed of the magnetostrictive vibration wave, the time T between the first coil 22 and the position indicator 12 The distance Ω, that is, the indicated position (coordinates) of the position indicator 12 can be calculated.

In the two-dimensional position detection device 11 shown in FIG.
0, the first multiplexer 25 and the second multiplexer 27 sequentially switch the connection between the first coil 22 and the pulse current generator 26 and the connection between the second coil 24 and the processing device 20, while A pulse current is applied to the coil 22, and the time T until the induced voltage V is generated in the second coil 24 is measured by the processing device 20.

That is, first, the first multiplexer 25 connects the first coil 2
2a to connect the pulse current generator 26 to the first coil 22a, and the second multiplexer 27 selects the second coil 24a to connect the processing device 20 to the second coil 24a. As shown in FIG. 2, when the position indicator 12p is present on the magnetostrictive transmission medium 21a1, when the magnetostrictive vibration wave reaches the position indicated by the position indicator 12p, the second coil 24a has a large An induced voltage Vyu is generated. Therefore, if the processing device 20 measures the time from the time when the pulse current is applied to the first coil 22a until the induced voltage v1 is detected, the first coil 22a
The distance Q1 from the part where a is wound to the position indicated by the position indicator 12p can be calculated. When the measurement of the magnetostrictive transmission medium 21a is completed, the first multiplexer 25 selects the first coil 22b, and the second multiplexer 27 selects the second coil 24b. Since there is no position indicator above the second coil 24b, no large induced voltage as described above is generated.In other words, since nothing is detected, no position is indicated on this second coil 24b. After the time has elapsed, the first multiplexer 25 selects the first coil 22c, and the second multiplexer 27 selects the second coil 24c. Since the position indicator 12q is present on the second coil 24c2, a large induced voltage v2 is generated, and the distance Q2 is determined as described above.

Note that one coil directly connected to the pulse current generator 26 is wound around the magnetostrictive transmission medium 21 in order without going through the multiplexers 25 and 27 to form the first coil, and a coil directly connected to the processing bag w20 is In the case where one coil is wound around the magnetostrictive transmission medium 21 to form the second coil, 2
If the positions indicated by two or more position indicators are close to each other, the induced voltages will interfere with each other, resulting in a detection result that looks as if one location is being indicated.

On the other hand, as described above, if the position indicated by the position indicator is detected separately for each magnetostrictive transmission medium 21 via the multiplexer 25, 27, two or more position indicators 12 to indicate two or more positions at the same time, the large induced voltages induced by these position indicators are prevented from interfering with each other as much as possible, so two or more positions should not be placed in close proximity. The position can be reliably detected even if the

Magnetostrictive transmission medium 21 and first coil 2 configured as above
If two sets of magnetostrictive transmission media 21 are provided and combined with their magnetostrictive transmission media 21 perpendicular to each other, a two-dimensional position detection device can be obtained, with the - set used for position detection in the X direction and the other set used for position detection in the Y direction. This means that you can configure

Vertical position detection device! 14 is a position indicator 12p, 1
It is a device that is provided on a base 13 having a diameter of 2q, detects a position in a direction perpendicular to a two-dimensional measurement surface A of the two-dimensional position detection device 11, and outputs a vertical position signal. This vertical position detection device 14 has a support 15 suspended on a base 13 at an intermediate position between the position indicators '2P* 12q, a slider 16 that slides along the support 15, and a probe attached to the slider 16. 17 is attached, and a conversion device 18 for converting the amount of movement of the slider 16 into an electric signal as a vertical position signal is built into the slider 16, and the output vertical position signal of the conversion device 18 can be taken out via a cable 19. It is.

Further, the output signals of the two-dimensional position detecting device 11 and the vertical position detecting device W14 are output together only when the probe 17 is in contact with the object to be measured.For example, a contact switch, a manual switch, etc. A more detailed structure of the vertical position detecting device 14, which can perform this operation, will be described later.

The signal from the two-dimensional position detection device 11 and the signal from the vertical position detection device 14 are supplied to the processing device 20. The processing device 20 is a device that processes and stores the above-mentioned signals and can display them on a CRT display or the like (not shown in the figure), and also controls the operation of circuits and the like within the two-dimensional position detection device 11.

FIG. 3 is a perspective view showing how the vertical position detection device 14 is installed. In the figure, position indicators 12P, 1
2q are arranged at regular intervals, and the position indicator 12p is located in the middle of the interval.

A column 15 is vertically disposed at a distance d from both the columns 12q and 12q. This support 15 has a prismatic shape, and has a guide surface 40 on its negative side. The shape of this support 15 is not limited to a prismatic shape, but may be any other shape as long as the amount of movement of the slider 16 can be detected as described later.However, the shape of the support 15 may be a cylinder or the like. slider 1
5 can be rotated around this support 15, two position indicators 12P, 1, as described later.
It is necessary to keep the direction of the probe 17 at a constant angle with respect to the vertical plane including 2q. Therefore, in conjunction with the rotation of the slider 16, the position indicators 12p and 12q
It is also necessary to have a structure that allows rotation around the pillar 15. Alternatively, the angle between the direction of the probe 17 and the above-mentioned vertical plane may be detected at all times. This is convenient because the direction of the probe 17 can be changed when measuring the three-dimensional coordinates of the object to be measured 4, and measurement can be carried out over a wide range while keeping the position of the base 13 constant.

The tip of the probe 17 attached to the slider 16 is located at a distance from the center line 0.

FIG. 4 is a diagram showing the conversion device 18 built into the slider 16. The converting device 18 has a speed reduction mechanism 41 and an encoder 42. The rotor 43 of the speed reduction mechanism 41 is brought into contact with a guide surface 40 provided on the support column 15, and the encoder is connected to the mechanical output end of the speed reduction mechanism 41. 42 is for installation. The output of the encoder 42 is connected to an output connector 45 via a lead wire 44. and.

When the slider 16 is moved, the rotor 43 rotates, and the rotation is appropriately decelerated via the deceleration mechanism 41 and transmitted to the encoder 42. The encoder 42 outputs the amount of movement of the slider 16, ie, a vertical position signal, in accordance with its rotation. Note that the support 15 and the slider 16 may have a structure similar to a so-called digital caliper.

Next, the principle for obtaining a two-dimensional position signal of the tip of the probe 17 will be explained with reference to FIGS. 5(1) to 2) and FIG. 6.

First, the tip of the probe 17 and the position indicator tzp, 12
The principle for obtaining the two-dimensional position of the tip of the probe 17 will be explained since the position is different from that of the tip of the probe 17.

As shown in FIG. 5 (1), position indicators 12p* 12q
The coordinates of (Xll 3'z) + (Xss 3'i
), the coordinates of the 0 point on the straight line r connecting these position indicators 12p and 12q are (< x t + x t )
/ 2 # < y 1 + y x ) / 2
), draw a perpendicular line from point 0 on the straight line r, and set the point with length L as the tip P of the probe 17, and define this point P as (x,
y). Then, the slope m of the straight line r is m= (ya
−yl) /(xi−xi) −−−−−−−°−
■The slope M of the line segment po is rlPo, so m-M=-1
Therefore, M=-(x□-X engineering)/(y,-y□)...
...■Here, as shown in Figure 5 (II), ΔPR
Considering O, if one side PR is 1, the side OR is.

(x z −x z ) / (y s −y t )
So, (xz'-X t) / (V m -3'
If z) is set as b, the hypotenuse op becomes fT]].

Therefore, if we divide the total by the hypotenuse 0P of ΔPRO = (r d wa] 7), we get the result shown in Fig. 5 (m).

The side PR is (1/(v'+b)), which is the side.

R is Cb/C (Ding Wa] P)].

Furthermore, when the length L of the probe 17 is multiplied by the length L of the probe 17 in FIG. 5 (III), as shown in FIG. 5 (mV), the hypotenuse OP
is L, the side PR is (L/C(Ding'TV')),
The side OR is [Lb/(f ℃ 7)).

The above content is on a straight line perpendicular to the straight line r, and the straight line ar
I found a point at a distance B from the point 0 above, and as shown in Figure 5 (I), this point is the distance between P and P'.
There will be a point. That is, the point P or P' is indicated depending on the direction in which the probe 17 is directed.

Subtracting the length of side PR (B, /(v'd1]7)) from the coordinates of point O gives X, and subtracting the length of side OR from the coordinates of point 0 (Lb/(
By subtracting ``v'TV''), we get y, and by adding the length of side PR (L/(7-17)) to the coordinates of point o, we get X'. Length (Lb/(4 pieces')
By adding TV')3, y' can be obtained.

This occurs because there are two position indicators 12p and 12q. In order to measure the shape of the object to be measured 4, P,
It must be determined which point of P' is the true measurement point.

As shown in FIG. 6, one corner of the two-dimensional position detection device 11 is set as the origin (0,0), and the opposite corner is set as the maximum point (X,.

V WIE ) and its midpoint is the reference point C, then
C is (xwm/2m'/yo/2), and when measuring, the object to be measured 4 is placed on this reference point C.

Then, during the measurement, the P obtained as described above was
Compare (x * y) and P'(x' + y').

The one having the value closer to the point C(Xwm/2, yyo/2) may be selected.

FIG. 7 is a diagram illustrating the 81II method. The object to be measured 4 is placed so that its center coincides with the reference point C,
Then, for example, measurement lines J3, . . . Jn are determined in the vertical direction of the surface of the object to be measured 4. Also, for each measurement line J1, J2, . . . Jn, vertical position measurement points P and P2. ...Determine Pa.

The probe 17 of the vertical position detection device 14 is moved to the vertical position measurement points P2, P3, ...Ps+ of the measurement line J1.
bring it into contact with. Position indicators 12p and 12q at this time
The two-dimensional position detection device 11 outputs the position as a two-dimensional position signal. Also, the vertical position at this time is
The vertical position detection device 14 detects and outputs a vertical position signal. In this way, when the measurement is completed, it is shifted to the measurement line J2 in the vertical direction.

The above measurement is performed again, and the entire circumference of the object to be measured (36
0 degree) or when a predetermined measurement area has been measured, the measurement is terminated, and the processing device 20 processes the signal obtained as a result of the measurement, thereby obtaining three-dimensional coordinates.

According to such an embodiment, it can be used without selecting any environmental conditions, and there are no points that cannot be measured.

FIG. 8 is a perspective view showing another embodiment of the three-dimensional coordinate input device according to the present invention.

The embodiment shown in FIG. 8 differs from the first embodiment in the shape of the probe. The probe 17' is.

Since the shape can be freely selected, by using the illustrated shape, even if the object to be measured 4 has a cylindrical shape, the inner circumferential surface of the object can be measured.

Furthermore, if the horizontal length of the probes 17 and 17' is made to be expandable and retractable, and the amount of expansion and contraction can be measured and inputted as a signal to the processing device 20, the base 1
While keeping 3 constant, set the vertical position measurement point P2,...
...Pa can be measured continuously.

In this embodiment, a device as shown in FIG. 2 is used as the two-dimensional position detecting device 11. However, it is also possible to detect the two-dimensional position using a two-dimensional position detecting device using other means. I don't mind.

Furthermore, although the explanation has been made regarding two position indicators 12p and 12q, there may be three or more, and as long as the three position indicators are arranged so that they are not on the same straight line, the measurement can be performed as described above. Since there are no multiple points to be
Calculation processing in the processing device can be performed more quickly.

〔Effect of the invention〕

As explained above, according to the three-dimensional input device according to the present invention, the two-dimensional position indicated by the position indicator can be detected by the two-dimensional position detecting device, and a vertical position signal can be obtained by the vertical position detecting device. Therefore, three-dimensional coordinates can be obtained at every measurement point.

Furthermore, since the three-dimensional coordinates are obtained mechanically, it is not affected by the external environment such as temperature.

Furthermore, since the measurement is performed in a mechanically semi-fixed state, the measurement point does not fluctuate and can be measured accurately.

In addition, the vertical position signal is accurate because the amount of movement along the column is slowed down by a conversion device and converted into an electrical signal.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a three-dimensional coordinate input device according to the present invention. FIG. 2 is a perspective view schematically showing a two-dimensional position detection device suitable for use in the same embodiment. FIG. 3 is a partially cutaway perspective view showing the positional relationship between the position indicator and the vertical position detection device. FIG. 4 is an explanatory diagram showing a schematic configuration of a converting device of a vertical position detecting device. FIG. 5 is an explanatory diagram for explaining the principle of determining the coordinates of the tip of the probe from the indicated point of the position indicator. FIG. 6 is an explanatory diagram shown to explain the principle of determining the coordinates of the tip of the probe when there are two position indicators. Figure 7 is. FIG. 2 is an explanatory diagram of a method for measuring an object using the present device. FIG. 8 is a perspective view showing another embodiment of the present invention. FIG. 9 is an explanatory diagram showing the principle of a conventional three-dimensional coordinate input device. FIG. 10 is a diagram for explaining the disadvantages of measurement using a conventional three-dimensional coordinate input device. 10... Three-dimensional coordinate input device 11... Two-dimensional position detection device 12p, 12q... Position indicator 13... Base 14... Vertical position detection device 15... Support 16... Slider 17
... Probe 18 ... Conversion device diagram

Claims (2)

[Claims] (1) A position indicator that indicates at least two points on two dimensions, a two-dimensional position detection device that detects the position indicated by the position indicator and outputs it as a two-dimensional position signal, and a position indicator that is provided in the position indicator. a vertical position detecting device that detects a position perpendicular to a two-dimensional measurement surface of the two-dimensional position detecting device and outputs a vertical position signal, and each of the two-dimensional position detecting device and the vertical position detecting device A three-dimensional coordinate input device comprising a processing device that processes, stores, and displays signals. (2) The vertical position detection device includes a support provided on the position indicator, and a slider that slides along the support.
2. The three-dimensional coordinate input device according to claim 1, comprising: a probe provided on the slider; and a conversion device that converts the amount of movement of the slider into an electrical signal.