JP2642818B2 - Position measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position measuring device for measuring the position of an object by bringing a contact or the like into contact with the object.

[0002]

2. Description of the Related Art A conventional example is disclosed in Japanese Patent Application Laid-Open No. 60-1042.
02 and JP-A-60-119402.

[0003]

Although it is stated that these can be measured even for articles having low rigidity, it is difficult to set a very low contact pressure because the moving mechanism of the contact is a parallel spring. The present invention has been made in view of the above points, and can provide a contact with an object to be measured with a very low contact pressure, can perform position detection with high resolution, and is obstructed by a position detection sensor. It is an object of the present invention to provide a position measuring device capable of detecting a position only by bringing only a contact into contact with an object to be measured without using a contact.

[0004]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a low friction moving mechanism comprising a fluid bearing or a magnetic bearing, and a linear DC actuator or an electromagnet for driving the low friction moving mechanism. Actuator means consisting of, and a position detection sensor provided at a position different from the measured object and detecting the position of the low friction moving mechanism,
A movable body provided in the low friction moving mechanism is provided, and a contact and a target used by the position detection sensor for position detection are provided on the movable body, and the contact comes into contact with the object to be measured.
The position of the low-friction moving mechanism at the time is determined by the position detection sensor.
The position of the object to be measured is detected by measuring .

According to a second aspect of the present invention, in the first aspect of the invention, an alarm is generated based on a detection output of a position detection sensor.
Control means for feedback control of the actuator
It is provided. According to the third aspect of the present invention, the first aspect
Driven by three or more actuator means
Equipped with a two-degree-of-freedom movable body in a low-friction moving mechanism that acts on force
And a contact on the movable body, and the position detection sensor
It detects the position of the movable body in two degrees of freedom.

[0006] In the invention of claim 4, the invention of claim 1 is provided.
And the driving force by three or more actuator means
Equipped with a 3-DOF movable body in the low-friction moving mechanism
A contact is provided on the body, and the position detection sensor has three freedoms of the movable body
Ru der detects the position of the degree.

[0007]

According to the first aspect of the present invention, the contact is provided on the low-friction moving mechanism, and the position detection sensor for detecting the position of the low-friction moving mechanism is provided at a position different from the object to be measured.
It is not necessary to provide a position detection sensor in the low friction moving mechanism, and a low friction moving mechanism with almost zero friction can be realized. Therefore, the force for moving the low friction moving mechanism depends only on the actuator means. The force is determined only by the performance, and a very delicate contact pressure can be realized, and the low frictional transfer when the contact comes into contact with the object to be measured.
Since the position of the moving mechanism is measured by the position detection sensor ,
The position of the object to be measured can be measured indirectly by detecting the position of the low-friction movement mechanism, so that the position can be detected by contacting only the contact with the object without being disturbed by the position detection sensor. Therefore, if the contact can be brought into contact, measurement can be performed, and restrictions on the object to be measured are reduced. Furthermore, since the movable body is provided with a target used by the position detection sensor for position detection, the position detection sensor can be arranged at a position corresponding to the target and at a position away from the contact, and the target is attached to the movable body. With this arrangement, the relationship between the position detection sensor and the object to be measured becomes clear via the target, and the accuracy of position detection by the position detection sensor is improved.

According to the invention of claim 2, according to claim 1,
In the invention of the above, based on the detection output of the position detection sensor
Control means for feedback control of actuator means
A step is provided to accurately detect the position of the low-friction moving mechanism
Position control, force control, compliance control,
Control, etc. Furthermore, according to the invention of claim 3,
The invention according to claim 1, wherein three or more actuator hands are provided.
Two-degree-of-freedom
A movable body is provided and a contact is provided on the movable body for position detection.
The output sensor detects the position of the movable body in two degrees of freedom,
Position detection in a plane can be accurately performed.

Further, according to the invention of claim 4, according to the invention,
Item 3. In the invention of Item 1, the three or more actuator means
With three degrees of freedom on a low friction moving mechanism with a driving force
Body, a contact is provided on the movable body, and the position detection sensor is
Since the position of the movable body with three degrees of freedom is detected, the position within the plane
And angle can be detected at once.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) Figs. 1 to 3 show this embodiment. In FIG. 1, a low-friction moving mechanism 1 uses an air bearing as a fluid bearing, and compressed air is sent from outside. A movable body 2 is movably provided as a one-axis table at the center of the low friction moving mechanism 1, and a contact 3 is attached to a lower surface of the movable body 2. A target 4 is provided on a side surface of the movable body 2, and a position detection sensor 5 for detecting the position of the low-friction moving mechanism 1 corresponding to the target 4.
Are arranged. That is, the position detection sensor 5 is provided at a position different from the position of the contact 3 to be brought into contact with the measured object,
By detecting the position of the low friction moving mechanism 1, the position of the object to be measured can be indirectly measured. Note that the fluid bearing of the low friction moving mechanism 1 may be configured as a liquid bearing.

Actuator for driving low friction moving mechanism 1
The linear DC actuator 6 serving as a motor means includes an E-shaped yoke 7 and a movable coil 8 inserted into the center of the yoke 7.
The movable coil 8 is a low-friction moving mechanism 1
Is connected to a support piece 9 provided on the movable body 2. Therefore, the movable body 2 is freely movable in the lateral direction. The linear DC actuator 6 uses a voice coil motor (VCM) here.

Further, control means for feedback controlling the linear DC actuator 6 based on the output of the position detecting sensor 5 is provided, and this control means is driven by the linear DC actuator 6 as shown in the control system of FIG. The position of the low-friction moving mechanism 1 is detected by the position detection sensor 5, and the linear DC actuator 6 is feedback-controlled based on the detection output of the position detection sensor 5 so that the detected position matches the desired position.

The movable body 2 of the low-friction moving mechanism 1 is driven by the linear DC actuator 6, and the contact 3
, And the position of the movable body 2 is detected by the position detection sensor 5 to measure the position. That is, the Lorentz force is applied to the movable body 2 by the linear DC actuator 6, so that the movable body 2 can be controlled at a predetermined position. In the damping, minute vibration from the outside by compressed air is handled by damping control of the linear DC actuator 6.

As described above, the current flowing to the electromagnetic force of the linear DC actuator 6 or the electromagnet can be controlled for the low-friction moving mechanism 1 capable of detecting the position, and by controlling the current value, each force can be controlled. Precisely detects the position of the low-friction moving mechanism 1 that has been generated arbitrarily and the known force has been applied, and can perform position control, force control, compliance control, damping control, etc., and can also detect force during control. Therefore, it can also have a function as a force sensor.Thus, for example, by simultaneously performing low-load force control and damping control, it becomes possible to minimize vibration and measure with low contact pressure. is there.

FIG. 3 shows an example using the configuration shown in FIG.
An X-axis table 12 and a Z-axis table 13 are installed on a gantry 11, and a workpiece 14, a stylus (stylus) 1
5, a work clamper 16, an actuator 17 and the like are provided. Here, the large stroke uses a general positioning device, and the small stroke uses the linear DC actuator 6 and the low friction moving mechanism 1 to accurately measure the position.

Embodiment 2 In this embodiment, as shown in FIGS. 4 and 5, a repulsion type magnetic bearing is used in place of the fluid bearing.
As shown in FIG. 5, a movable body 2 composed of a magnetized permanent magnet 18 and a permanent magnet 18
And a permanent magnet 19 that is magnetized so as to be repelled from the movable body 2, and a contact 3 is attached to the lower surface of the movable body 2.

As described above, according to the present embodiment, a magnetic bearing which moves on one axis is provided as a low friction moving mechanism, and a contact is arranged in a part of the low friction moving mechanism to detect the position of an article. There are two types of magnetic bearings: an active control type using electromagnets and a passive type using permanent magnets.The passive type using permanent magnets is particularly inferior in rigidity to fluid bearings, but the fluid path Since there is no need for design, the device can be simplified.

(Embodiment 3) In this embodiment, as shown in FIGS. 6 and 7, a linear DC actuator 6 and a low friction moving mechanism 1 composed of an air bearing are integrally formed. In the present embodiment, by integrating the linear DC actuator 6 and the one-axis low-friction moving mechanism 1, the device can be made compact, and the size and weight can be reduced.

(Embodiment 4) In this embodiment, as shown in FIGS.
) And a low friction moving mechanism 1
Three or more activators that apply suction and repulsion to a movable body
Detects the position of the electromagnet 20 and the movable body
Position detection sensor 5 with two degrees of freedom in a plane and position detection
Each electromagnet 20 is fed back based on the output of the sensor 5.
Control means (not shown) for controlling the magnet 20
With the suction force of the above, the suction force that can control the position of the movable body with two degrees of freedom
To enable the movable body to be controlled at a desired position.
It is a thing. This makes it possible to accurately detect the position in the plane.
Can be done well.

In this embodiment, secondary (X, Y) control is performed.
Yes, points on the plane can be measured . The third order
Can be attached instead of the original measuring instrument probe
You. FIG. 9 shows an example of the measurement system. (Embodiment 5) This embodiment is directed to an air bearing as shown in FIGS.
Low friction moving mechanism 1 and movable body of low friction moving mechanism 1
Linear DC actuators 6 for applying force to
And three-degree-of-freedom position detection to detect the position of the movable body
Based on the output of the sensor 5, each linear DC actuator
Control means (not shown) for feedback-controlling the
It is provided.

Then, the linear DC actuator 6
The movable body is made to act on the moving body with a force that can be controlled in three degrees of freedom.
Can be controlled at a desired position and angle.
The contact 3 is arranged on a part of the movable body,
At a time (simultaneously).
Can be. Also, instead of a probe for a 3D measuring device
Can also be attached.

(Embodiment 6) In this embodiment, as shown in FIGS.
It is a constant current I (one
Apply acceleration and load with constant force F) and measure the stop point of contact 3
Is to be specified. That is, a constant current
A By flowing the current through the movable coil 8 of the DC actuator 6
A constant force is generated, and the contact 3 is moved to the article, that is, the object 10 to be measured.
Move the low-friction moving mechanism 1 at constant acceleration until it contacts
After the contact 3 comes into contact with the DUT 10, the constant force
The position is measured under the measurement pressure. Follow
Without feedback control, at the desired measurement pressure,
It can be easily measured.

(Embodiment 7) In this embodiment, as shown in FIG. 14 and FIG.
This is based on the target position increase method using the measurement method.
The target position is brought closer to the DUT 10 by
Minimize impact by measuring stop points
doing. That is, the value of the position detection sensor 5 is input and
And a feedback that outputs the coil current of the movable coil 8.
Control is performed, and the target position of the low-friction moving mechanism 1 is set to one step.
Approach the device under test 10 at a time and provide feedback
When the current exceeds the coil current required for the contact pressure,
Check the contact (stop) and measure the position with the desired measurement pressure.
Things. This reduces the impact on the article
it can.

(Embodiment 8) In this embodiment, as shown in FIG. 16 and FIG.
This is based on the target position setting method using the measurement method.
Position within the range that always hits the DUT
Re-set the measurement to a lower load and measure at the maximum speed.
I'm trying. That is, the value of the position detection sensor 5 is entered.
And the coil current of the movable coil 8 as output.
The contact 3 collides with the DUT 10.
The target position of the low friction moving mechanism 1 is set
Is detected by the position detection sensor 5 and then reaches a desired measurement pressure.
It converts and measures the position. This allows the measured
Since the fixed object 10 can be reached quickly, the measurement speed is increased.

[0025]

According to the first aspect of the present invention, the contact is provided on the low-friction moving mechanism, and the position detecting sensor for detecting the position of the low-friction moving mechanism is provided at a position different from the object to be measured.
It is not necessary to provide a position detection sensor in the low friction moving mechanism, and a low friction moving mechanism with almost zero friction can be realized. Therefore, the force for moving the low friction moving mechanism depends only on the actuator means. The force is determined only by the performance, and a very delicate contact pressure can be realized, and the low frictional transfer when the contact comes into contact with the object to be measured.
Since the position of the moving mechanism is measured by the position detection sensor ,
The position of the object to be measured can be measured indirectly by detecting the position of the low-friction movement mechanism, so that the position can be detected by contacting only the contact with the object without being disturbed by the position detection sensor. Therefore, if the contact can be brought into contact, measurement is possible, and there is an effect that the restriction on the object to be measured is reduced. Further, since the movable body is provided with a target used by the position detection sensor for position detection, the position detection sensor is provided. Can be placed at a position corresponding to the target and at a position away from the contact, and by providing the target on the movable body, the relationship between the position detection sensor and the DUT can be clearly defined via the target. to become the position detection in which the position detection accuracy of the sensor is improved, especially contactors cell within the movable range of the actuator means <br/> Tsu Te I Ngusa If it is, it naturally be moved the movable body,
There is an operational effect that the contact can be brought into contact with the measured object at an arbitrary contact pressure.

The invention of claim 2 is the invention of claim 1.
In the case of
Control means for feedback control of the tutor means is provided.
The position of the low-friction moving mechanism is precisely detected because
Control, force control, compliance control, damping control
And the like. Further, the invention of claim 3
The invention according to claim 1, wherein three or more actuators
2 free for low friction moving mechanism where the driving force is applied by
With a movable body and a contact on the movable body.
The position detection sensor detects the position of the movable body in two degrees of freedom.
It is said that it is possible to accurately detect the position in the plane
Has the effect.

Further, the invention of claim 4 is the invention of claim 1
In the invention, drive by three or more actuator means
Equipped with a three-degree-of-freedom movable body in a low-friction moving mechanism that acts on power.
A contact is provided on the movable body, and the position detection sensor is
Position of three degrees of freedom is detected.
Can be detected at once.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of a control system of the above.

FIG. 3 is a perspective view showing an example of the measurement system of the above.

FIG. 4 is a schematic configuration diagram of Embodiment 2 of the above.

FIG. 5 is a schematic configuration diagram of Embodiment 2 of the above.

FIG. 6 is a perspective view of the third embodiment.

FIG. 7 is a schematic configuration diagram of the above.

FIG. 8 It is a perspective view of Example 4 same as the above.

FIG. 9 FIG. 2 is a perspective view showing an example of the measurement system of the above.
You.

FIG. 10 It is a perspective view of Example 5 same as the above.

FIG. 11 FIG. 2 is a perspective view showing an example of the measurement system of the above.
You.

FIG. It is explanatory drawing of Example 6 same as the above.

FIG. 13 It is a figure which shows the flowchart same as the above.

FIG. 14 It is explanatory drawing of Example 7 same as the above.

FIG. It is a figure which shows the flowchart same as the above.

FIG. 16 It is explanatory drawing of Example 8 same as the above.

FIG. It is a figure which shows the flowchart same as the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low friction movement mechanism 2 Movable body 3 Contact 5 Position detection sensor 6 Linear DC actuator 8 Movable coil 10 DUT

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Hara 1048 Odomo Kadoma, Kadoma, Osaka Pref. Matsushita Electric Works, Ltd. (JP, A) JP-A-63-302477 (JP, A)

Claims (4)

(57) [Claims] 1. A low-friction moving mechanism comprising a fluid bearing or a magnetic bearing; an actuator means comprising a linear DC actuator or an electromagnet for driving the low-friction moving mechanism; a position detection sensor for detecting the position of the mechanism provided with a movable body provided in the low friction moving mechanism, and contacts the movable body, provided the target position detection sensor is used to detect the position, the contact is Low friction when contacting the object
Measuring the position of the moving mechanism with a position detection sensor
Position measuring device according to feature to detect the position of the object to be measured by. 2. The position measuring device according to claim 1, further comprising control means for performing feedback control of the actuator means based on a detection output of the position detection sensor. 3. A low-friction moving mechanism to which a driving force is applied by three or more actuators is provided with a movable body having two degrees of freedom and a contact is provided on the movable body. The position measuring device according to claim 1, wherein the position is detected. 4. A low-friction moving mechanism, to which a driving force is applied by three or more actuators, includes a movable member having three degrees of freedom, a contact is provided on the movable member, and the position detection sensor has three degrees of freedom of the movable member. 2. The method according to claim 1, wherein the position is detected.
The position measuring device as described.