JPH087053B2 - Object position measurement method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring an object position, which is used, for example, for installing a magnet in an accelerator and can measure the object position with respect to a reference line with high accuracy.

[0002]

2. Description of the Related Art Conventionally, in order to measure the position of an object with respect to a reference line, a contact type displacement gauge such as a micrometer is used, and a wire such as a piano wire that matches the reference line is used and an object. And the method of measuring the amount of displacement. In this method, a certain pressing force when the tip of the micrometer contacts the reference wire material has a great influence on the measurement accuracy and requires skill. That is, if the pressing force of the micrometer is strong, the reference wire material escapes and the measurement accuracy fluctuates greatly. Therefore, in order to confirm whether the tip of the micrometer is in contact with the reference wire or not, a visual method using light such as a magnifying glass to irradiate the light, or a method of confirming by the presence or absence of electrical contact Are known.

FIG. 7 is a perspective view showing a configuration using a conventional object position measuring method which is confirmed by the presence or absence of electrical contact. On the support table 1a, a magnet 2 used as an accelerator, for example, is placed as an object whose position is measured via the air table 1b. A reference block 5 is provided on the magnet 2 for displaying the reference position of the magnet 2, and is fixedly supported by the reference block retainer 6. A contact between the wire 3 (diameter 0.1 mm) such as a piano wire, which is a reference wire, and the micrometer 4 fixed to the reference block 5 is detected by using a tester 7 on one end 8 of the wire 3 and on the reference block 5. The tester 7 is checked depending on whether or not a current is conducted between it and one point.
Check for the occurrence of a buzzer sound.

FIG. 8 is a diagram showing a configuration using a visual measurement method by irradiating light. Similar to FIG. 7, the micrometer 4 is fixed to the reference block 5 on the magnet 2, and the reference block retainer 6 is provided to fix and support the reference block 5. The contact between the wire 3 and the micrometer 4 is visually confirmed by irradiating light and using a magnifying glass or the like.

[0005]

The visual method has a drawback that the measuring position differs depending on the position of the eyes of the measurer, and the measuring accuracy is about 20 to 30 μm. Further, in the case of the method of generating the buzzer sound, the buzzer sound is not generated because the contact resistance is large unless the tip of the micrometer sufficiently contacts the reference wire. When the tip of the micrometer is sufficiently in contact with the reference wire, the pressing force of the micrometer against the reference wire is large, resulting in a large error, and it is not possible to obtain a correct measurement value. Further, in order to improve the measurement accuracy, it is necessary that the micrometer is in contact and the bending when the reference wire is strained is small, and the measurement accuracy of the outer diameter of the reference wire is good. The diameter of the reference wire is shown in FIG.
It is better to make it as thin as possible as in m), but if this is done, the difference in electrical resistance will increase due to the difference in measurement position, and the pressing amount of the micrometer against the reference wire will not be constant.

In order to solve the above-mentioned drawbacks, JP-A-48-5
In the invention proposed by 449, the contact pressure can be set small by increasing the resistance value of the detector such as a tester as much as possible, but the contact pressure is not completely eliminated. There is a limit to the measurement accuracy. Furthermore, depending on the surrounding environment, when there is wind, the reference wire also sways, which causes an error in measurement. That is, the mechanical dimension measuring instrument used as the contact type displacement gauge guarantees the measuring accuracy of the measuring instrument for the first time when the object to be measured such as the reference wire and the measuring contact terminal are completely in contact with each other. . Therefore, when the object to be measured is not fixed and is moved or deformed for measurement, the accuracy of the measured value is significantly reduced.

An object of the present invention is to provide an object position measuring method capable of measuring an object position with respect to a reference line with high accuracy without being affected by the movement of a reference wire or the like.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a step of measuring the displacement amount of an object and a reference wire which is aligned with a reference line by using a contact type displacement meter, and a step of contacting by a non-contact type displacement meter are used. Measuring the amount of deflection of the reference wire at the position of the non-contact type displacement gauge with respect to the reference line generated by the displacement type displacement gauge, and the amount of deflection measured at the position of the non-contact type displacement gauge at the position of the contact type displacement gauge. A step of converting the deflection amount, and a step of measuring the object position with respect to the reference line by correcting the displacement amount measured using the contact displacement meter using the deflection amount at the position of the contact displacement meter. The object position measuring method is characterized by including.

[0009]

According to the present invention, the amount of displacement between the object to be measured and the reference wire which has been previously aligned with the reference line is measured using the contact displacement meter. Since the contact-type displacement gauge is brought into contact with the reference wire to perform the measurement, the amount of deflection between the reference wire and the reference wire caused by the tension applied to the reference wire is measured using the non-contact displacement gauge. Since the non-contact displacement gauge measures the amount of deflection without contacting the reference wire, the amount of deflection due to the use of the non-contact displacement gauge does not occur, and the reference line and the reference wire produced only by the contact displacement gauge It is possible to measure the amount of flexure. Even if the measurement position of the non-contact type displacement gauge is not the same as the measurement position of the contact type displacement gauge, it is measured at the position of the non-contact type displacement gauge by conducting the bending analysis of the reference wire rod under tension beforehand. The amount of bending is converted into the amount of bending at the position of the contact displacement meter. The displacement amount measured using the contact displacement gauge is corrected by taking the difference between the displacement amount measured using the contact displacement gauge and the amount of deflection at the position of the contact displacement gauge, and the displacement with respect to the reference line is corrected. The object position can be measured with high accuracy.

[0010]

1 is a perspective view of an embodiment using the object position measuring method of the present invention. The magnet 12, which is an object whose position is to be measured, is fixedly supported by the air table 11b and installed on the support table 11a. Hereinafter, a method for highly accurately measuring the position of the magnet 12 fixed to the air table 11b on the support table 11a will be described. The wire 13 such as a piano wire, which is a reference wire, is pulled so as not to bend from both ends of the support table 11a, and is fixed so that the wire 13 is aligned with the reference line. In order to display the reference position of the magnet 12, the reference block 15 is installed on the magnet 12 and fixedly supported by the reference block retainer 16. In order to measure the amount of displacement between the reference block 15 and the wire 13, the micrometer 14 is fixed on the reference block 15 so that the wire 13 and the center line of the micrometer 14 are aligned with each other. The displacement amount between the reference block 15 and the wire 13 is measured by the micrometer 14. Whether or not the micrometer 14 has come into contact with the wire 13 is confirmed by irradiating light and visually observing.

It should be noted that the measurement is performed by using the micrometer 14 which is a contact type displacement meter and the optical outer diameter measuring device 20 which is a non-contact type displacement meter.
The optical outer diameter measuring device 20 emits and receives light by the detecting unit 17 configured in a U-shape, and measures the displacement amount of the measurement object inserted in the U-shaped space portion. The detection unit 17 of the optical outer diameter measuring device 20 is installed on the support table 11a. The wire 13 is inserted and arranged in the U-shaped space portion of the detection unit 17 as a measurement object. At this time, support table 1
The installation position along the longitudinal direction of the wire 13 of the micrometer 14 on the 1a and the installation position along the longitudinal direction of the wire 13 of the detection unit 17 of the optical outer diameter measuring device 20 are measured in advance, and the micrometer When the wire 13 is bent at the installation positions of 14, the amount of bending of the wire 13 at both installation positions is calculated. The recorder 19 is connected to the optical outer diameter measuring device 20, and the edge of the wire 13 in a stationary state of the wire 13 is measured and recorded in the recorder 19. Next, the micrometer 14 is brought into contact with the wire 13 and is pressed by a slight amount to bend the wire 13. The displacement amount between the reference block 15 and the wire 13 is measured from the value of the micrometer 14 at this time, and the edge of the wire 13 is also measured by the optical outer diameter measuring device 20.
From the measurement result recorded in the recorder 19 in the stationary state of the wire 13 and the measurement result measured using the optical outer diameter measuring device 20 when the wire 13 is bent,
The amount of displacement of the wire 13, that is, the amount of bending of the wire 13 at the installation position of the detection unit 17 is obtained. The installation position of the micrometer 14 calculated in advance and the detection unit 17
The amount of bending of the wire 13 at the installation position of the micrometer 14 is converted from the relationship of the amount of bending of the wire 13 at the installation position of. To accurately measure the position of the magnet 12 with respect to the wire 13 by subtracting the amount of deflection of the wire 13 at the installation position of the micrometer 14 from the amount of displacement between the reference block 15 and the wire 13 measured by the micrometer 14. You can

FIG. 2 is a diagram showing the principle of the object position measuring method of the present invention. An object 22 such as a magnet to be measured is placed on a mounting table 21 such as a support table. Reference wire 23 such as a wire from both ends of the mounting base 21
Is pulled so as not to bend, and is installed so as to coincide with the reference line 25 indicated by a broken line. In FIG. 2, a contact type displacement gauge 24 such as a micrometer is brought into contact with the reference wire 23,
And a certain amount of pressure is applied, tension is applied, and the reference wire 23
Shows a state in which it bends to the position indicated by the straight line 26. Xm
Is the amount of displacement between the object 22 and the reference wire 23 measured by the contact displacement meter 24, and Xb is the optical outer diameter measuring device 20.
A reference wire 2 with respect to the reference line 25 at the installation position of the non-contact type displacement meter 27 measured by the non-contact type displacement meter 27 such as
The amount of deflection, Xa, of the reference wire rod 2 with respect to the reference line 25 at the installation position of the contact displacement meter 24 is converted from Xb.
Deflection amount Xo of 3 is the distance L between the object 22 and the reference line 25.
“A” indicates the distance from one end of the mounting table 21 to the installation position of the contact type displacement meter 24, and “Lb” indicates the distance from one end of the mounting table 21 to the installation position of the non-contact displacement meter 27.

If the relationship between the amount of deflection of the reference wire 23 and the distance from one end of the reference wire 23 is calculated in advance and the amount of deflection is displayed as a function F of the distance, the displacement is measured by the non-contact displacement gauge 27. Xb and La, Lb to Xa measured in advance are functions of Xb, La, Lb, that is, Xa = F
It can be represented by (Xb, La, Lb). Xo can be obtained by subtracting Xa from Xm measured by the contact displacement meter 24 (Xo = Xm-Xa).
For example, if the weight of the reference wire 23 is ignored, L
Since the relationship of a: Xa = Lb: Xb is established,

[0014]

[Equation 1]

Can be expressed as In calculating the function F, if the weight of the reference wire 23 is taken into consideration, a more accurate Xo can be obtained, which is desirable.

FIG. 3 shows the measurement results shown on the display section 18 of the optical outer diameter measuring device 20 which is a non-contact type displacement gauge. The vertical axis represents time (seconds) and the horizontal axis represents voltage (mV), and the voltage (mV) corresponds to the amount of deflection (μm). Optical outer diameter measuring device 2 in a stationary state of the wire 13 which is the reference wire
A measurement result indicating the edge position of the wire 13 using 0 is indicated by an arrow 28, and the micrometer 1 which is a contact type displacement meter.
An arrow 29 indicates a measurement result indicating the edge position of the wire 13 using the optical outer diameter measuring device 20 in the contact state between the wire 4 and the wire 13. Micrometer 14 is wire 1
As a result of the wire 13 bending due to contact with the wire 3, the edge position of the wire 13 is displaced, and the voltage value indicated by the arrow 28 changes to the voltage value indicated by the arrow 29. Therefore, arrow 2
The difference between the two measurement results shown by 8 and 29 is the amount of bending of the wire 13 measured by the optical outer diameter measuring device 20.

FIG. 4 is a block diagram showing the configuration of the optical outer diameter measuring device 20 used in the method of the present invention shown in FIG. Light emitted from a light emitting diode (hereinafter referred to as “LED”) 31 provided in the U-shaped detection unit 17 is collimated through a lens 32a and is applied to the wire 13 which is an object. Since the shape portion of the wire 13 does not transmit light, light and darkness of the light is created, and the light and dark portion of the light condensed through the lens 32b has a light and dark portion as a charge transfer device (hereinafter, “CCD”).
A plurality of light receiving elements 33) are imaged on a light receiving surface arranged in a straight line and converted into a light receiving signal corresponding thereto. CC
The D drive circuit 34 transmits a signal for driving the LED to the LED drive circuit 35 at the same timing as driving the CCD 33. An analog signal sent from the CCD 33 is converted into a digital signal by an analog-digital converter (hereinafter referred to as “A / D converter”) 36. Also CCD
The A / D converter 36 is sampled by the drive circuit 34. The digital signal from the A / D converter 36 is sent to the edge detection circuit 37, and the digital data having a certain output value or more is removed to detect the edge of the digital data. After that, in the central processing unit (hereinafter referred to as “CPU”) 38, the edge position of the wire 13 is calculated as a function of the voltage value corresponding to the edge of the digital data. The outer diameter of the wire 13 is obtained from the edge of the digital data based on the relationship between the magnification of the lens diameter and the pitch of the light receiving element. In addition, the CPU 38 improves the accuracy by measuring the edge position of the object by projecting and receiving such light a plurality of times and taking the average. It should be noted that data and the like necessary for data processing in the CPU 38 are input from the data input device 39. Data representing the measurement result of the edge position of the wire 13 in a stationary state of the wire 13 is converted from the CPU 38 into an analog signal by the digital-analog converter (D / A converter) 40 and recorded in the recorder 19. The measurement result of the edge position of the wire 13 in the bent state of the wire 13 is also the CPU 3 similarly.
The data is processed at 8, and the data in the still state of the wire 13 recorded in the recorder 19 is displayed on the display unit 18 as shown in the graph of FIG. As shown in the graph of FIG. 3, the amount of deflection obtained is the amount of displacement of the edge position that changes depending on whether the wire 13 is stationary or in a deflected state. Further, the interface 41 may be connected to the CPU 38 to perform data communication with a computer or the like.

5 and 6 show examples in which it is very effective to use the method of the invention. FIG. 5 shows a magnet 12 for focusing an electron beam used in the accelerator, and FIG. 6 is a cross-sectional view of the magnet taken along the section line A in FIG. As shown in FIG. 5, a plurality of magnets 1
2 are installed to accelerate the electron 44 and the electron 44
A tube 43a connecting the magnet 12a and the magnet 12b is provided as a passage of the. The electrons are accelerated each time they pass through the magnet. In the cross section of the magnet shown in FIG. 6 taken along the section line A, the coil magnets 46a, 46b,
46c and 46d are extended inward from four directions,
The magnetic pole can be changed by the electric current. A passage 45 for passing the electrons 44 is provided in the center.
While passing through the passage 45, the electron 44 accelerated by the change of the magnetic pole is extracted as an electron beam, but its focus is several μm.
Since a high accuracy of m unit is required, it is extremely effective for installing the magnet 12 by applying the method of the present invention. When the method of the present invention is used, the measurement reproducibility can be measured at ± 1 μm without being affected by the individual difference of the measurer.

[0019]

As described above, according to the present invention, the displacement amount between the object and the reference wire rod, which is measured by using the contact displacement gauge,
Since the amount of deflection at the position of the contact type displacement gauge converted from the amount of deflection between the reference line and the reference wire measured at the position of the non-contact type displacement gauge is used for correction, the object position with respect to the reference line is highly accurate. In addition, the measured values can be easily measured without individual differences. Furthermore, since the conventional contact type displacement meter can be used without any modification, it is possible to reduce the equipment cost without using an expensive measuring instrument.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment using the object position measuring method of the present invention.

FIG. 2 is a diagram showing the principle of the object position measuring method of the present invention.

FIG. 3 is a measurement result displayed on a detection unit 18 of an optical outer diameter measuring device 20 which is a non-contact type displacement meter.

FIG. 4 is a block diagram showing a configuration of an optical outer diameter measuring device 20 used in the object position measuring method of the present invention.

FIG. 5 is a perspective view of a magnet as an example in which it is effective to use the object position measuring method of the present invention.

6 is a cross-sectional view of the magnet shown in FIG. 5 taken along the section line A. FIG.

FIG. 7 is a perspective view showing a configuration using a conventional object position measuring method which is confirmed by the presence or absence of electrical contact.

FIG. 8 is a diagram showing a configuration in which a measuring method by irradiating light and visually observing is used.

[Explanation of symbols]

 11a Support table 11b Air table 12 Magnet 13 Wire 14 Micrometer 15 Reference block 16 Reference block retainer 17 Detecting unit 18 Display unit 19 Recorder 20 Optical outside diameter measuring instrument 21 Installation table 22 Object 23 Reference wire 24 Contact displacement meter 25 Reference Line 27 Non-contact displacement meter 31 Light emitting diode (LED) 32a, 32b Lens 33 Charge transfer device (CCD) 37 Edge detection circuit 38 Central processing unit (CPU) 39 Data input section

Claims (1)

[Claims] 1. A step of measuring a displacement amount of an object and a reference wire material matched on a reference line using a contact displacement meter, and a reference line generated by the contact displacement meter using a non-contact displacement meter. A step of measuring the amount of deflection of the reference wire at the position of the non-contact type displacement gauge, and a step of converting the amount of deflection measured at the position of the non-contact type displacement meter into the amount of deflection at the position of the contact type displacement meter, An object that is characterized by including a step of measuring an object position with respect to a reference line by correcting a displacement amount measured using a contact displacement meter using a deflection amount at a position of the contact displacement meter. Position measurement method.